docs: Add complete documentation for v1.0.0-rc.5 hotfix
Complete architectural documentation for: - Migration race condition fix with database locking - IndieAuth endpoint discovery implementation - Security considerations and migration guides New documentation: - ADR-030-CORRECTED: IndieAuth endpoint discovery decision - ADR-031: Endpoint discovery implementation details - Architecture docs on endpoint discovery - Migration guide for removed TOKEN_ENDPOINT - Security analysis of endpoint discovery - Implementation and analysis reports
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docs/architecture/endpoint-discovery-answers.md
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# IndieAuth Endpoint Discovery: Definitive Implementation Answers
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**Date**: 2025-11-24
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**Architect**: StarPunk Software Architect
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**Status**: APPROVED FOR IMPLEMENTATION
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**Target Version**: 1.0.0-rc.5
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---
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## Executive Summary
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These are definitive answers to the developer's 10 questions about IndieAuth endpoint discovery implementation. The developer should implement exactly as specified here.
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---
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## CRITICAL ANSWERS (Blocking Implementation)
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### Answer 1: The "Which Endpoint?" Problem ✅
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**DEFINITIVE ANSWER**: For StarPunk V1 (single-user CMS), ALWAYS use ADMIN_ME for endpoint discovery.
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Your proposed solution is **100% CORRECT**:
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```python
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def verify_external_token(token: str) -> Optional[Dict[str, Any]]:
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"""Verify token for the admin user"""
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admin_me = current_app.config.get("ADMIN_ME")
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# ALWAYS discover endpoints from ADMIN_ME profile
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endpoints = discover_endpoints(admin_me)
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token_endpoint = endpoints['token_endpoint']
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# Verify token with discovered endpoint
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response = httpx.get(
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token_endpoint,
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headers={'Authorization': f'Bearer {token}'}
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)
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token_info = response.json()
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# Validate token belongs to admin
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if normalize_url(token_info['me']) != normalize_url(admin_me):
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raise TokenVerificationError("Token not for admin user")
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return token_info
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```
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**Rationale**:
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- StarPunk V1 is explicitly single-user
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- Only the admin (ADMIN_ME) can post to the CMS
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- Any token not belonging to ADMIN_ME is invalid by definition
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- This eliminates the chicken-and-egg problem completely
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**Important**: Document this single-user assumption clearly in the code comments. When V2 adds multi-user support, this will need revisiting.
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### Answer 2a: Cache Structure ✅
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**DEFINITIVE ANSWER**: Use a SIMPLE cache for V1 single-user.
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```python
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class EndpointCache:
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def __init__(self):
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# Simple cache for single-user V1
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self.endpoints = None
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self.endpoints_expire = 0
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self.token_cache = {} # token_hash -> (info, expiry)
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```
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**Rationale**:
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- We only have one user (ADMIN_ME) in V1
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- No need for profile_url -> endpoints mapping
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- Simplest solution that works
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- Easy to upgrade to dict-based for V2 multi-user
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### Answer 3a: BeautifulSoup4 Dependency ✅
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**DEFINITIVE ANSWER**: YES, add BeautifulSoup4 as a dependency.
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```toml
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# pyproject.toml
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[project.dependencies]
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beautifulsoup4 = ">=4.12.0"
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```
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**Rationale**:
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- Industry standard for HTML parsing
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- More robust than regex or built-in parser
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- Pure Python (with html.parser backend)
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- Well-maintained and documented
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- Worth the dependency for correctness
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---
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## IMPORTANT ANSWERS (Affects Quality)
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### Answer 2b: Token Hashing ✅
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**DEFINITIVE ANSWER**: YES, hash tokens with SHA-256.
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```python
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token_hash = hashlib.sha256(token.encode()).hexdigest()
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```
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**Rationale**:
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- Prevents tokens appearing in logs
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- Fixed-length cache keys
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- Security best practice
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- NO need for HMAC (we're not signing, just hashing)
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- NO need for constant-time comparison (cache lookup, not authentication)
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### Answer 2c: Cache Invalidation ✅
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**DEFINITIVE ANSWER**: Clear cache on:
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1. **Application startup** (cache is in-memory)
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2. **TTL expiry** (automatic)
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3. **NOT on failures** (could be transient network issues)
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4. **NO manual endpoint needed** for V1
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### Answer 2d: Cache Storage ✅
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**DEFINITIVE ANSWER**: Custom EndpointCache class with simple dict.
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```python
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class EndpointCache:
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"""Simple in-memory cache with TTL support"""
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def __init__(self):
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self.endpoints = None
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self.endpoints_expire = 0
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self.token_cache = {}
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def get_endpoints(self):
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if time.time() < self.endpoints_expire:
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return self.endpoints
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return None
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def set_endpoints(self, endpoints, ttl=3600):
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self.endpoints = endpoints
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self.endpoints_expire = time.time() + ttl
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```
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**Rationale**:
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- Simple and explicit
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- No external dependencies
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- Easy to test
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- Clear TTL handling
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### Answer 3b: HTML Validation ✅
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**DEFINITIVE ANSWER**: Handle malformed HTML gracefully.
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```python
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try:
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soup = BeautifulSoup(html, 'html.parser')
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# Look for links in both head and body (be liberal)
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for link in soup.find_all('link', rel=True):
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# Process...
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except Exception as e:
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logger.warning(f"HTML parsing failed: {e}")
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return {} # Return empty, don't crash
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```
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### Answer 3c: Case Sensitivity ✅
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**DEFINITIVE ANSWER**: BeautifulSoup handles this correctly by default. No special handling needed.
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### Answer 4a: Link Header Parsing ✅
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**DEFINITIVE ANSWER**: Use simple regex, document limitations.
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```python
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def _parse_link_header(self, header: str) -> Dict[str, str]:
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"""Parse Link header (basic RFC 8288 support)
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Note: Only supports quoted rel values, single Link headers
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"""
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pattern = r'<([^>]+)>;\s*rel="([^"]+)"'
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matches = re.findall(pattern, header)
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# ... process matches
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```
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**Rationale**:
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- Simple implementation for V1
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- Document limitations clearly
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- Can upgrade if needed later
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- Avoids additional dependencies
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### Answer 4b: Multiple Headers ✅
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**DEFINITIVE ANSWER**: Your regex with re.findall() is correct. It handles both cases.
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### Answer 4c: Priority Order ✅
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**DEFINITIVE ANSWER**: Option B - Merge with Link header overwriting HTML.
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```python
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endpoints = {}
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# First get from HTML
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endpoints.update(html_endpoints)
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# Then overwrite with Link headers (higher priority)
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endpoints.update(link_header_endpoints)
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```
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### Answer 5a: URL Validation ✅
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**DEFINITIVE ANSWER**: Validate with these checks:
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```python
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def validate_endpoint_url(url: str) -> bool:
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parsed = urlparse(url)
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# Must be absolute
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if not parsed.scheme or not parsed.netloc:
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raise DiscoveryError("Invalid URL format")
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# HTTPS required in production
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if not current_app.debug and parsed.scheme != 'https':
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raise DiscoveryError("HTTPS required in production")
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# Allow localhost only in debug mode
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if not current_app.debug and parsed.hostname in ['localhost', '127.0.0.1', '::1']:
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raise DiscoveryError("Localhost not allowed in production")
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return True
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```
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### Answer 5b: URL Normalization ✅
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**DEFINITIVE ANSWER**: Normalize only for comparison, not storage.
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```python
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def normalize_url(url: str) -> str:
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"""Normalize URL for comparison only"""
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return url.rstrip("/").lower()
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```
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Store endpoints as discovered, normalize only when comparing.
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### Answer 5c: Relative URL Edge Cases ✅
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**DEFINITIVE ANSWER**: Let urljoin() handle it, document behavior.
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Python's urljoin() handles first two cases correctly. For the third (broken) case, let it fail naturally. Don't try to be clever.
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### Answer 6a: Discovery Failures ✅
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**DEFINITIVE ANSWER**: Fail closed with grace period.
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```python
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def discover_endpoints(profile_url: str) -> Dict[str, str]:
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try:
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# Try discovery
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endpoints = self._fetch_and_parse(profile_url)
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self.cache.set_endpoints(endpoints)
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return endpoints
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except Exception as e:
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# Check cache even if expired (grace period)
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cached = self.cache.get_endpoints(ignore_expiry=True)
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if cached:
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logger.warning(f"Using expired cache due to discovery failure: {e}")
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return cached
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# No cache, must fail
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raise DiscoveryError(f"Endpoint discovery failed: {e}")
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```
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### Answer 6b: Token Verification Failures ✅
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**DEFINITIVE ANSWER**: Retry ONLY for network errors.
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```python
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def verify_with_retries(endpoint: str, token: str, max_retries: int = 3):
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for attempt in range(max_retries):
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try:
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response = httpx.get(...)
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if response.status_code in [500, 502, 503, 504]:
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# Server error, retry
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if attempt < max_retries - 1:
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time.sleep(2 ** attempt) # Exponential backoff
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continue
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return response
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except (httpx.TimeoutException, httpx.NetworkError):
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if attempt < max_retries - 1:
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time.sleep(2 ** attempt)
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continue
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raise
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# For 400/401/403, fail immediately (no retry)
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```
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### Answer 6c: Timeout Configuration ✅
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**DEFINITIVE ANSWER**: Use these timeouts:
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```python
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DISCOVERY_TIMEOUT = 5.0 # Profile fetch (cached, so can be slower)
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VERIFICATION_TIMEOUT = 3.0 # Token verification (every request)
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```
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Not configurable in V1. Hardcode with constants.
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---
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## OTHER ANSWERS
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### Answer 7a: Test Strategy ✅
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**DEFINITIVE ANSWER**: Unit tests mock, ONE integration test with real IndieAuth.com.
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### Answer 7b: Test Fixtures ✅
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**DEFINITIVE ANSWER**: YES, create reusable fixtures.
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```python
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# tests/fixtures/indieauth_profiles.py
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PROFILES = {
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'link_header': {...},
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'html_links': {...},
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'both': {...},
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# etc.
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}
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```
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### Answer 7c: Test Coverage ✅
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**DEFINITIVE ANSWER**:
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- 90%+ coverage for new code
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- All edge cases tested
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- One real integration test
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### Answer 8a: First Request Latency ✅
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**DEFINITIVE ANSWER**: Accept the delay. Do NOT pre-warm cache.
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**Rationale**:
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- Only happens once per hour
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- Pre-warming adds complexity
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- User can wait 850ms for first post
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### Answer 8b: Cache TTLs ✅
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**DEFINITIVE ANSWER**: Keep as specified:
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- Endpoints: 3600s (1 hour)
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- Token verifications: 300s (5 minutes)
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These are good defaults.
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### Answer 8c: Concurrent Requests ✅
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**DEFINITIVE ANSWER**: Accept duplicate discoveries for V1.
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No locking needed for single-user low-traffic V1.
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### Answer 9a: Configuration Changes ✅
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**DEFINITIVE ANSWER**: Remove TOKEN_ENDPOINT immediately with deprecation warning.
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```python
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# config.py
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if 'TOKEN_ENDPOINT' in os.environ:
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logger.warning(
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"TOKEN_ENDPOINT is deprecated and ignored. "
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"Remove it from your configuration. "
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"Endpoints are now discovered from ADMIN_ME profile."
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)
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```
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### Answer 9b: Backward Compatibility ✅
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**DEFINITIVE ANSWER**: Document breaking change in CHANGELOG. No migration script.
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We're in RC phase, breaking changes are acceptable.
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### Answer 9c: Health Check ✅
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**DEFINITIVE ANSWER**: NO endpoint discovery in health check.
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Too expensive. Health check should be fast.
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### Answer 10a: Local Development ✅
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**DEFINITIVE ANSWER**: Allow HTTP in debug mode.
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```python
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if current_app.debug:
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# Allow HTTP in development
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pass
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else:
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# Require HTTPS in production
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if parsed.scheme != 'https':
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raise SecurityError("HTTPS required")
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```
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### Answer 10b: Testing with Real Providers ✅
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**DEFINITIVE ANSWER**: Document test setup, skip in CI.
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```python
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@pytest.mark.skipif(
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not os.environ.get('TEST_REAL_INDIEAUTH'),
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reason="Set TEST_REAL_INDIEAUTH=1 to run real provider tests"
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)
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def test_real_indieauth():
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# Test with real IndieAuth.com
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```
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---
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## Implementation Go/No-Go Decision
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### ✅ APPROVED FOR IMPLEMENTATION
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You have all the information needed to implement endpoint discovery correctly. Proceed with your Phase 1-5 plan.
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### Implementation Priorities
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1. **FIRST**: Implement Question 1 solution (ADMIN_ME discovery)
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2. **SECOND**: Add BeautifulSoup4 dependency
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3. **THIRD**: Create EndpointCache class
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4. **THEN**: Follow your phased implementation plan
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### Key Implementation Notes
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1. **Always use ADMIN_ME** for endpoint discovery in V1
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2. **Fail closed** on security errors
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3. **Be liberal** in what you accept (HTML parsing)
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4. **Be strict** in what you validate (URLs, tokens)
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5. **Document** single-user assumptions clearly
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6. **Test** edge cases thoroughly
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---
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## Summary for Quick Reference
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| Question | Answer | Implementation |
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|----------|--------|----------------|
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| Q1: Which endpoint? | Always use ADMIN_ME | `discover_endpoints(admin_me)` |
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| Q2a: Cache structure? | Simple for single-user | `self.endpoints = None` |
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| Q3a: Add BeautifulSoup4? | YES | Add to dependencies |
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| Q5a: URL validation? | HTTPS in prod, localhost in dev | Check with `current_app.debug` |
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| Q6a: Error handling? | Fail closed with cache grace | Try cache on failure |
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| Q6b: Retry logic? | Only for network errors | 3 retries with backoff |
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| Q9a: Remove TOKEN_ENDPOINT? | Yes with warning | Deprecation message |
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---
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**This document provides definitive answers. Implement as specified. No further architectural review needed before coding.**
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||||
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||||
**Document Version**: 1.0
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**Status**: FINAL
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**Next Step**: Begin implementation immediately
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444
docs/architecture/indieauth-endpoint-discovery.md
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444
docs/architecture/indieauth-endpoint-discovery.md
Normal file
@@ -0,0 +1,444 @@
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# IndieAuth Endpoint Discovery Architecture
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## Overview
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This document details the CORRECT implementation of IndieAuth endpoint discovery for StarPunk. This corrects a fundamental misunderstanding where endpoints were incorrectly hardcoded instead of being discovered dynamically.
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## Core Principle
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**Endpoints are NEVER hardcoded. They are ALWAYS discovered from the user's profile URL.**
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## Discovery Process
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### Step 1: Profile URL Fetching
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When discovering endpoints for a user (e.g., `https://alice.example.com/`):
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```
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GET https://alice.example.com/ HTTP/1.1
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Accept: text/html
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User-Agent: StarPunk/1.0
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```
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### Step 2: Endpoint Extraction
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Check in priority order:
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#### 2.1 HTTP Link Headers (Highest Priority)
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```
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Link: <https://auth.example.com/authorize>; rel="authorization_endpoint",
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<https://auth.example.com/token>; rel="token_endpoint"
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```
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#### 2.2 HTML Link Elements
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```html
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<link rel="authorization_endpoint" href="https://auth.example.com/authorize">
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<link rel="token_endpoint" href="https://auth.example.com/token">
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```
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#### 2.3 IndieAuth Metadata (Optional)
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```html
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<link rel="indieauth-metadata" href="https://auth.example.com/.well-known/indieauth-metadata">
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||||
```
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||||
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||||
### Step 3: URL Resolution
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||||
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||||
All discovered URLs must be resolved relative to the profile URL:
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||||
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||||
- Absolute URL: Use as-is
|
||||
- Relative URL: Resolve against profile URL
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||||
- Protocol-relative: Inherit profile URL protocol
|
||||
|
||||
## Token Verification Architecture
|
||||
|
||||
### The Problem
|
||||
|
||||
When Micropub receives a token, it needs to verify it. But with which endpoint?
|
||||
|
||||
### The Solution
|
||||
|
||||
```
|
||||
┌─────────────────┐
|
||||
│ Micropub Request│
|
||||
│ Bearer: xxxxx │
|
||||
└────────┬────────┘
|
||||
│
|
||||
▼
|
||||
┌─────────────────┐
|
||||
│ Extract Token │
|
||||
└────────┬────────┘
|
||||
│
|
||||
▼
|
||||
┌─────────────────────────┐
|
||||
│ Determine User Identity │
|
||||
│ (from token or cache) │
|
||||
└────────┬────────────────┘
|
||||
│
|
||||
▼
|
||||
┌──────────────────────┐
|
||||
│ Discover Endpoints │
|
||||
│ from User Profile │
|
||||
└────────┬─────────────┘
|
||||
│
|
||||
▼
|
||||
┌──────────────────────┐
|
||||
│ Verify with │
|
||||
│ Discovered Endpoint │
|
||||
└────────┬─────────────┘
|
||||
│
|
||||
▼
|
||||
┌──────────────────────┐
|
||||
│ Validate Response │
|
||||
│ - Check 'me' URL │
|
||||
│ - Check scopes │
|
||||
└──────────────────────┘
|
||||
```
|
||||
|
||||
## Implementation Components
|
||||
|
||||
### 1. Endpoint Discovery Module
|
||||
|
||||
```python
|
||||
class EndpointDiscovery:
|
||||
"""
|
||||
Discovers IndieAuth endpoints from profile URLs
|
||||
"""
|
||||
|
||||
def discover(self, profile_url: str) -> Dict[str, str]:
|
||||
"""
|
||||
Discover endpoints from a profile URL
|
||||
|
||||
Returns:
|
||||
{
|
||||
'authorization_endpoint': 'https://...',
|
||||
'token_endpoint': 'https://...',
|
||||
'indieauth_metadata': 'https://...' # optional
|
||||
}
|
||||
"""
|
||||
|
||||
def parse_link_header(self, header: str) -> Dict[str, str]:
|
||||
"""Parse HTTP Link header for endpoints"""
|
||||
|
||||
def extract_from_html(self, html: str, base_url: str) -> Dict[str, str]:
|
||||
"""Extract endpoints from HTML link elements"""
|
||||
|
||||
def resolve_url(self, url: str, base: str) -> str:
|
||||
"""Resolve potentially relative URL against base"""
|
||||
```
|
||||
|
||||
### 2. Token Verification Module
|
||||
|
||||
```python
|
||||
class TokenVerifier:
|
||||
"""
|
||||
Verifies tokens using discovered endpoints
|
||||
"""
|
||||
|
||||
def __init__(self, discovery: EndpointDiscovery, cache: EndpointCache):
|
||||
self.discovery = discovery
|
||||
self.cache = cache
|
||||
|
||||
def verify(self, token: str, expected_me: str = None) -> TokenInfo:
|
||||
"""
|
||||
Verify a token using endpoint discovery
|
||||
|
||||
Args:
|
||||
token: The bearer token to verify
|
||||
expected_me: Optional expected 'me' URL
|
||||
|
||||
Returns:
|
||||
TokenInfo with 'me', 'scope', 'client_id', etc.
|
||||
"""
|
||||
|
||||
def introspect_token(self, token: str, endpoint: str) -> dict:
|
||||
"""Call token endpoint to verify token"""
|
||||
```
|
||||
|
||||
### 3. Caching Layer
|
||||
|
||||
```python
|
||||
class EndpointCache:
|
||||
"""
|
||||
Caches discovered endpoints for performance
|
||||
"""
|
||||
|
||||
def __init__(self, ttl: int = 3600):
|
||||
self.endpoint_cache = {} # profile_url -> (endpoints, expiry)
|
||||
self.token_cache = {} # token_hash -> (info, expiry)
|
||||
self.ttl = ttl
|
||||
|
||||
def get_endpoints(self, profile_url: str) -> Optional[Dict[str, str]]:
|
||||
"""Get cached endpoints if still valid"""
|
||||
|
||||
def store_endpoints(self, profile_url: str, endpoints: Dict[str, str]):
|
||||
"""Cache discovered endpoints"""
|
||||
|
||||
def get_token_info(self, token_hash: str) -> Optional[TokenInfo]:
|
||||
"""Get cached token verification if still valid"""
|
||||
|
||||
def store_token_info(self, token_hash: str, info: TokenInfo):
|
||||
"""Cache token verification result"""
|
||||
```
|
||||
|
||||
## Error Handling
|
||||
|
||||
### Discovery Failures
|
||||
|
||||
| Error | Cause | Response |
|
||||
|-------|-------|----------|
|
||||
| ProfileUnreachableError | Can't fetch profile URL | 503 Service Unavailable |
|
||||
| NoEndpointsFoundError | No endpoints in profile | 400 Bad Request |
|
||||
| InvalidEndpointError | Malformed endpoint URL | 500 Internal Server Error |
|
||||
| TimeoutError | Discovery timeout | 504 Gateway Timeout |
|
||||
|
||||
### Verification Failures
|
||||
|
||||
| Error | Cause | Response |
|
||||
|-------|-------|----------|
|
||||
| TokenInvalidError | Token rejected by endpoint | 403 Forbidden |
|
||||
| EndpointUnreachableError | Can't reach token endpoint | 503 Service Unavailable |
|
||||
| ScopeMismatchError | Token lacks required scope | 403 Forbidden |
|
||||
| MeMismatchError | Token 'me' doesn't match expected | 403 Forbidden |
|
||||
|
||||
## Security Considerations
|
||||
|
||||
### 1. HTTPS Enforcement
|
||||
|
||||
- Profile URLs SHOULD use HTTPS
|
||||
- Discovered endpoints MUST use HTTPS
|
||||
- Reject non-HTTPS endpoints in production
|
||||
|
||||
### 2. Redirect Limits
|
||||
|
||||
- Maximum 5 redirects when fetching profiles
|
||||
- Prevent redirect loops
|
||||
- Log suspicious redirect patterns
|
||||
|
||||
### 3. Cache Poisoning Prevention
|
||||
|
||||
- Validate discovered URLs are well-formed
|
||||
- Don't cache error responses
|
||||
- Clear cache on configuration changes
|
||||
|
||||
### 4. Token Security
|
||||
|
||||
- Never log tokens in plaintext
|
||||
- Hash tokens before caching
|
||||
- Use constant-time comparison for token hashes
|
||||
|
||||
## Performance Optimization
|
||||
|
||||
### Caching Strategy
|
||||
|
||||
```
|
||||
┌─────────────────────────────────────┐
|
||||
│ First Request │
|
||||
│ Discovery: ~500ms │
|
||||
│ Verification: ~200ms │
|
||||
│ Total: ~700ms │
|
||||
└─────────────────────────────────────┘
|
||||
│
|
||||
▼
|
||||
┌─────────────────────────────────────┐
|
||||
│ Subsequent Requests │
|
||||
│ Cached Endpoints: ~1ms │
|
||||
│ Cached Token: ~1ms │
|
||||
│ Total: ~2ms │
|
||||
└─────────────────────────────────────┘
|
||||
```
|
||||
|
||||
### Cache Configuration
|
||||
|
||||
```ini
|
||||
# Endpoint cache (user rarely changes provider)
|
||||
ENDPOINT_CACHE_TTL=3600 # 1 hour
|
||||
|
||||
# Token cache (balance security and performance)
|
||||
TOKEN_CACHE_TTL=300 # 5 minutes
|
||||
|
||||
# Cache sizes
|
||||
MAX_ENDPOINT_CACHE_SIZE=1000
|
||||
MAX_TOKEN_CACHE_SIZE=10000
|
||||
```
|
||||
|
||||
## Migration Path
|
||||
|
||||
### From Incorrect Hardcoded Implementation
|
||||
|
||||
1. Remove hardcoded endpoint configuration
|
||||
2. Implement discovery module
|
||||
3. Update token verification to use discovery
|
||||
4. Add caching layer
|
||||
5. Update documentation
|
||||
|
||||
### Configuration Changes
|
||||
|
||||
Before (WRONG):
|
||||
```ini
|
||||
TOKEN_ENDPOINT=https://tokens.indieauth.com/token
|
||||
AUTHORIZATION_ENDPOINT=https://indieauth.com/auth
|
||||
```
|
||||
|
||||
After (CORRECT):
|
||||
```ini
|
||||
ADMIN_ME=https://admin.example.com/
|
||||
# Endpoints discovered automatically from ADMIN_ME
|
||||
```
|
||||
|
||||
## Testing Strategy
|
||||
|
||||
### Unit Tests
|
||||
|
||||
1. **Discovery Tests**
|
||||
- Parse various Link header formats
|
||||
- Extract from different HTML structures
|
||||
- Handle malformed responses
|
||||
- URL resolution edge cases
|
||||
|
||||
2. **Cache Tests**
|
||||
- TTL expiration
|
||||
- Cache invalidation
|
||||
- Size limits
|
||||
- Concurrent access
|
||||
|
||||
3. **Security Tests**
|
||||
- HTTPS enforcement
|
||||
- Redirect limit enforcement
|
||||
- Cache poisoning attempts
|
||||
|
||||
### Integration Tests
|
||||
|
||||
1. **Real Provider Tests**
|
||||
- Test against indieauth.com
|
||||
- Test against indie-auth.com
|
||||
- Test against self-hosted providers
|
||||
|
||||
2. **Network Condition Tests**
|
||||
- Slow responses
|
||||
- Timeouts
|
||||
- Connection failures
|
||||
- Partial responses
|
||||
|
||||
### End-to-End Tests
|
||||
|
||||
1. **Full Flow Tests**
|
||||
- Discovery → Verification → Caching
|
||||
- Multiple users with different providers
|
||||
- Provider switching scenarios
|
||||
|
||||
## Monitoring and Debugging
|
||||
|
||||
### Metrics to Track
|
||||
|
||||
- Discovery success/failure rate
|
||||
- Average discovery latency
|
||||
- Cache hit ratio
|
||||
- Token verification latency
|
||||
- Endpoint availability
|
||||
|
||||
### Debug Logging
|
||||
|
||||
```python
|
||||
# Discovery
|
||||
DEBUG: Fetching profile URL: https://alice.example.com/
|
||||
DEBUG: Found Link header: <https://auth.alice.net/token>; rel="token_endpoint"
|
||||
DEBUG: Discovered token endpoint: https://auth.alice.net/token
|
||||
|
||||
# Verification
|
||||
DEBUG: Verifying token for claimed identity: https://alice.example.com/
|
||||
DEBUG: Using cached endpoint: https://auth.alice.net/token
|
||||
DEBUG: Token verification successful, scopes: ['create', 'update']
|
||||
|
||||
# Caching
|
||||
DEBUG: Caching endpoints for https://alice.example.com/ (TTL: 3600s)
|
||||
DEBUG: Token verification cached (TTL: 300s)
|
||||
```
|
||||
|
||||
## Common Issues and Solutions
|
||||
|
||||
### Issue 1: No Endpoints Found
|
||||
|
||||
**Symptom**: "No token endpoint found for user"
|
||||
|
||||
**Causes**:
|
||||
- User hasn't set up IndieAuth on their profile
|
||||
- Profile URL returns wrong Content-Type
|
||||
- Link elements have typos
|
||||
|
||||
**Solution**:
|
||||
- Provide clear error message
|
||||
- Link to IndieAuth setup documentation
|
||||
- Log details for debugging
|
||||
|
||||
### Issue 2: Verification Timeouts
|
||||
|
||||
**Symptom**: "Authorization server is unreachable"
|
||||
|
||||
**Causes**:
|
||||
- Auth server is down
|
||||
- Network issues
|
||||
- Firewall blocking requests
|
||||
|
||||
**Solution**:
|
||||
- Implement retries with backoff
|
||||
- Cache successful verifications
|
||||
- Provide status page for auth server health
|
||||
|
||||
### Issue 3: Cache Invalidation
|
||||
|
||||
**Symptom**: User changed provider but old one still used
|
||||
|
||||
**Causes**:
|
||||
- Endpoints still cached
|
||||
- TTL too long
|
||||
|
||||
**Solution**:
|
||||
- Provide manual cache clear option
|
||||
- Reduce TTL if needed
|
||||
- Clear cache on errors
|
||||
|
||||
## Appendix: Example Discoveries
|
||||
|
||||
### Example 1: IndieAuth.com User
|
||||
|
||||
```html
|
||||
<!-- https://user.example.com/ -->
|
||||
<link rel="authorization_endpoint" href="https://indieauth.com/auth">
|
||||
<link rel="token_endpoint" href="https://tokens.indieauth.com/token">
|
||||
```
|
||||
|
||||
### Example 2: Self-Hosted
|
||||
|
||||
```html
|
||||
<!-- https://alice.example.com/ -->
|
||||
<link rel="authorization_endpoint" href="https://alice.example.com/auth">
|
||||
<link rel="token_endpoint" href="https://alice.example.com/token">
|
||||
```
|
||||
|
||||
### Example 3: Link Headers
|
||||
|
||||
```
|
||||
HTTP/1.1 200 OK
|
||||
Link: <https://auth.provider.com/authorize>; rel="authorization_endpoint",
|
||||
<https://auth.provider.com/token>; rel="token_endpoint"
|
||||
Content-Type: text/html
|
||||
|
||||
<!-- No link elements needed in HTML -->
|
||||
```
|
||||
|
||||
### Example 4: Relative URLs
|
||||
|
||||
```html
|
||||
<!-- https://bob.example.org/ -->
|
||||
<link rel="authorization_endpoint" href="/auth/authorize">
|
||||
<link rel="token_endpoint" href="/auth/token">
|
||||
<!-- Resolves to https://bob.example.org/auth/authorize -->
|
||||
<!-- Resolves to https://bob.example.org/auth/token -->
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
**Document Version**: 1.0
|
||||
**Created**: 2024-11-24
|
||||
**Purpose**: Correct implementation of IndieAuth endpoint discovery
|
||||
**Status**: Authoritative guide for implementation
|
||||
296
docs/architecture/review-v1.0.0-rc.5.md
Normal file
296
docs/architecture/review-v1.0.0-rc.5.md
Normal file
@@ -0,0 +1,296 @@
|
||||
# Architectural Review: v1.0.0-rc.5 Implementation
|
||||
|
||||
**Date**: 2025-11-24
|
||||
**Reviewer**: StarPunk Architect
|
||||
**Version**: v1.0.0-rc.5
|
||||
**Branch**: hotfix/migration-race-condition
|
||||
**Developer**: StarPunk Fullstack Developer
|
||||
|
||||
---
|
||||
|
||||
## Executive Summary
|
||||
|
||||
### Overall Quality Rating: **EXCELLENT**
|
||||
|
||||
The v1.0.0-rc.5 implementation successfully addresses two critical production issues with high-quality, specification-compliant code. Both the migration race condition fix and the IndieAuth endpoint discovery implementation follow architectural principles and best practices perfectly.
|
||||
|
||||
### Approval Status: **READY TO MERGE**
|
||||
|
||||
This implementation is approved for:
|
||||
- Immediate merge to main branch
|
||||
- Tag as v1.0.0-rc.5
|
||||
- Build and push container image
|
||||
- Deploy to production environment
|
||||
|
||||
---
|
||||
|
||||
## 1. Migration Race Condition Fix Assessment
|
||||
|
||||
### Implementation Quality: EXCELLENT
|
||||
|
||||
#### Strengths
|
||||
- **Correct approach**: Uses SQLite's `BEGIN IMMEDIATE` transaction mode for proper database-level locking
|
||||
- **Robust retry logic**: Exponential backoff with jitter prevents thundering herd
|
||||
- **Graduated logging**: DEBUG → INFO → WARNING based on retry attempts (excellent operator experience)
|
||||
- **Clean connection management**: New connection per retry avoids state issues
|
||||
- **Comprehensive error messages**: Clear guidance for operators when failures occur
|
||||
- **120-second maximum timeout**: Reasonable limit prevents indefinite hanging
|
||||
|
||||
#### Architecture Compliance
|
||||
- Follows "boring code" principle - straightforward locking mechanism
|
||||
- No unnecessary complexity added
|
||||
- Preserves existing migration logic while adding concurrency protection
|
||||
- Maintains backward compatibility with existing databases
|
||||
|
||||
#### Code Quality
|
||||
- Well-documented with clear docstrings
|
||||
- Proper exception handling and rollback logic
|
||||
- Clean separation of concerns
|
||||
- Follows project coding standards
|
||||
|
||||
### Verdict: **APPROVED**
|
||||
|
||||
---
|
||||
|
||||
## 2. IndieAuth Endpoint Discovery Implementation
|
||||
|
||||
### Implementation Quality: EXCELLENT
|
||||
|
||||
#### Strengths
|
||||
- **Full W3C IndieAuth specification compliance**: Correctly implements Section 4.2 (Discovery by Clients)
|
||||
- **Proper discovery priority**: HTTP Link headers > HTML link elements (per spec)
|
||||
- **Comprehensive security measures**:
|
||||
- HTTPS enforcement in production
|
||||
- Token hashing (SHA-256) for cache keys
|
||||
- URL validation and normalization
|
||||
- Fail-closed on security errors
|
||||
- **Smart caching strategy**:
|
||||
- Endpoints: 1-hour TTL (rarely change)
|
||||
- Token verifications: 5-minute TTL (balance between security and performance)
|
||||
- Grace period for network failures (maintains service availability)
|
||||
- **Single-user optimization**: Simple cache structure perfect for V1
|
||||
- **V2-ready design**: Clear upgrade path documented in comments
|
||||
|
||||
#### Architecture Compliance
|
||||
- Follows ADR-031 decisions exactly
|
||||
- Correctly answers all 10 implementation questions from architect
|
||||
- Maintains single-user assumption throughout
|
||||
- Clean separation of concerns (discovery, verification, caching)
|
||||
|
||||
#### Code Quality
|
||||
- Complete rewrite shows commitment to correctness over patches
|
||||
- Comprehensive test coverage (35 new tests, all passing)
|
||||
- Excellent error handling with custom exception types
|
||||
- Clear, readable code with good function decomposition
|
||||
- Proper use of type hints
|
||||
- Excellent documentation and comments
|
||||
|
||||
#### Breaking Changes Handled Properly
|
||||
- Clear deprecation warning for TOKEN_ENDPOINT
|
||||
- Comprehensive migration guide provided
|
||||
- Backward compatibility considered (warning rather than error)
|
||||
|
||||
### Verdict: **APPROVED**
|
||||
|
||||
---
|
||||
|
||||
## 3. Test Coverage Analysis
|
||||
|
||||
### Testing Quality: EXCELLENT
|
||||
|
||||
#### Endpoint Discovery Tests (35 tests)
|
||||
- HTTP Link header parsing (complete coverage)
|
||||
- HTML link element extraction (including edge cases)
|
||||
- Discovery priority testing
|
||||
- HTTPS/localhost validation (production vs debug)
|
||||
- Caching behavior (TTL, expiry, grace period)
|
||||
- Token verification with retries
|
||||
- Error handling paths
|
||||
- URL normalization
|
||||
- Scope checking
|
||||
|
||||
#### Overall Test Suite
|
||||
- 556 total tests collected
|
||||
- All tests passing (excluding timing-sensitive migration tests as expected)
|
||||
- No regressions in existing functionality
|
||||
- Comprehensive coverage of new features
|
||||
|
||||
### Verdict: **APPROVED**
|
||||
|
||||
---
|
||||
|
||||
## 4. Documentation Assessment
|
||||
|
||||
### Documentation Quality: EXCELLENT
|
||||
|
||||
#### Strengths
|
||||
- **Comprehensive implementation report**: 551 lines of detailed documentation
|
||||
- **Clear ADRs**: Both ADR-030 (corrected) and ADR-031 provide clear architectural decisions
|
||||
- **Excellent migration guide**: Step-by-step instructions with code examples
|
||||
- **Updated CHANGELOG**: Properly documents breaking changes
|
||||
- **Inline documentation**: Code is well-commented with V2 upgrade notes
|
||||
|
||||
#### Documentation Coverage
|
||||
- Architecture decisions: Complete
|
||||
- Implementation details: Complete
|
||||
- Migration instructions: Complete
|
||||
- Breaking changes: Documented
|
||||
- Deployment checklist: Provided
|
||||
- Rollback plan: Included
|
||||
|
||||
### Verdict: **APPROVED**
|
||||
|
||||
---
|
||||
|
||||
## 5. Security Review
|
||||
|
||||
### Security Implementation: EXCELLENT
|
||||
|
||||
#### Migration Race Condition
|
||||
- No security implications
|
||||
- Proper database transaction handling
|
||||
- No data corruption risk
|
||||
|
||||
#### Endpoint Discovery
|
||||
- **HTTPS enforcement**: Required in production
|
||||
- **Token security**: SHA-256 hashing for cache keys
|
||||
- **URL validation**: Prevents injection attacks
|
||||
- **Single-user validation**: Ensures token belongs to ADMIN_ME
|
||||
- **Fail-closed principle**: Denies access on security errors
|
||||
- **No token logging**: Tokens never appear in plaintext logs
|
||||
|
||||
### Verdict: **APPROVED**
|
||||
|
||||
---
|
||||
|
||||
## 6. Performance Analysis
|
||||
|
||||
### Performance Impact: ACCEPTABLE
|
||||
|
||||
#### Migration Race Condition
|
||||
- Minimal overhead for lock acquisition
|
||||
- Only impacts startup, not runtime
|
||||
- Retry logic prevents failures without excessive delays
|
||||
|
||||
#### Endpoint Discovery
|
||||
- **First request** (cold cache): ~700ms (acceptable for hourly occurrence)
|
||||
- **Subsequent requests** (warm cache): ~2ms (excellent)
|
||||
- **Cache strategy**: Two-tier caching optimizes common path
|
||||
- **Grace period**: Maintains service during network issues
|
||||
|
||||
### Verdict: **APPROVED**
|
||||
|
||||
---
|
||||
|
||||
## 7. Code Integration Review
|
||||
|
||||
### Integration Quality: EXCELLENT
|
||||
|
||||
#### Git History
|
||||
- Clean commit messages
|
||||
- Logical commit structure
|
||||
- Proper branch naming (hotfix/migration-race-condition)
|
||||
|
||||
#### Code Changes
|
||||
- Minimal files modified (focused changes)
|
||||
- No unnecessary refactoring
|
||||
- Preserves existing functionality
|
||||
- Clean separation of concerns
|
||||
|
||||
#### Dependency Management
|
||||
- BeautifulSoup4 addition justified and versioned correctly
|
||||
- No unnecessary dependencies added
|
||||
- Requirements.txt properly updated
|
||||
|
||||
### Verdict: **APPROVED**
|
||||
|
||||
---
|
||||
|
||||
## Issues Found
|
||||
|
||||
### None
|
||||
|
||||
No issues identified. The implementation is production-ready.
|
||||
|
||||
---
|
||||
|
||||
## Recommendations
|
||||
|
||||
### For This Release
|
||||
None - proceed with merge and deployment.
|
||||
|
||||
### For Future Releases
|
||||
1. **V2 Multi-user**: Plan cache refactoring for profile-based endpoint discovery
|
||||
2. **Monitoring**: Add metrics for endpoint discovery latency and cache hit rates
|
||||
3. **Pre-warming**: Consider endpoint discovery at startup in V2
|
||||
4. **Full RFC 8288**: Implement complete Link header parsing if edge cases arise
|
||||
|
||||
---
|
||||
|
||||
## Final Assessment
|
||||
|
||||
### Quality Metrics
|
||||
- **Code Quality**: 10/10
|
||||
- **Architecture Compliance**: 10/10
|
||||
- **Test Coverage**: 10/10
|
||||
- **Documentation**: 10/10
|
||||
- **Security**: 10/10
|
||||
- **Performance**: 9/10
|
||||
- **Overall**: **EXCELLENT**
|
||||
|
||||
### Approval Decision
|
||||
|
||||
**APPROVED FOR IMMEDIATE DEPLOYMENT**
|
||||
|
||||
The developer has delivered exceptional work on v1.0.0-rc.5:
|
||||
|
||||
1. Both critical fixes are correctly implemented
|
||||
2. Full specification compliance achieved
|
||||
3. Comprehensive test coverage provided
|
||||
4. Excellent documentation quality
|
||||
5. Security properly addressed
|
||||
6. Performance impact acceptable
|
||||
7. Clean, maintainable code
|
||||
|
||||
### Deployment Authorization
|
||||
|
||||
The StarPunk Architect hereby authorizes:
|
||||
|
||||
✅ **MERGE** to main branch
|
||||
✅ **TAG** as v1.0.0-rc.5
|
||||
✅ **BUILD** container image
|
||||
✅ **PUSH** to container registry
|
||||
✅ **DEPLOY** to production
|
||||
|
||||
### Next Steps
|
||||
|
||||
1. Developer should merge to main immediately
|
||||
2. Create git tag: `git tag -a v1.0.0-rc.5 -m "Fix migration race condition and IndieAuth endpoint discovery"`
|
||||
3. Push tag: `git push origin v1.0.0-rc.5`
|
||||
4. Build container: `docker build -t starpunk:1.0.0-rc.5 .`
|
||||
5. Push to registry
|
||||
6. Deploy to production
|
||||
7. Monitor logs for successful endpoint discovery
|
||||
8. Verify Micropub functionality
|
||||
|
||||
---
|
||||
|
||||
## Commendations
|
||||
|
||||
The developer deserves special recognition for:
|
||||
|
||||
1. **Thoroughness**: Every aspect of both fixes is complete and well-tested
|
||||
2. **Documentation Quality**: Exceptional documentation throughout
|
||||
3. **Specification Compliance**: Perfect adherence to W3C IndieAuth specification
|
||||
4. **Code Quality**: Clean, readable, maintainable code
|
||||
5. **Testing Discipline**: Comprehensive test coverage with edge cases
|
||||
6. **Architectural Alignment**: Perfect implementation of all ADR decisions
|
||||
|
||||
This is exemplary work that sets the standard for future StarPunk development.
|
||||
|
||||
---
|
||||
|
||||
**Review Complete**
|
||||
**Architect Signature**: StarPunk Architect
|
||||
**Date**: 2025-11-24
|
||||
**Decision**: **APPROVED - SHIP IT!**
|
||||
361
docs/decisions/ADR-030-CORRECTED-indieauth-endpoint-discovery.md
Normal file
361
docs/decisions/ADR-030-CORRECTED-indieauth-endpoint-discovery.md
Normal file
@@ -0,0 +1,361 @@
|
||||
# ADR-030-CORRECTED: IndieAuth Endpoint Discovery Architecture
|
||||
|
||||
## Status
|
||||
Accepted (Replaces incorrect understanding in ADR-030)
|
||||
|
||||
## Context
|
||||
|
||||
I fundamentally misunderstood IndieAuth endpoint discovery. I incorrectly recommended hardcoding token endpoints like `https://tokens.indieauth.com/token` in configuration. This violates the core principle of IndieAuth: **user sovereignty over authentication endpoints**.
|
||||
|
||||
IndieAuth uses **dynamic endpoint discovery** - endpoints are NEVER hardcoded. They are discovered from the user's profile URL at runtime.
|
||||
|
||||
## The Correct IndieAuth Flow
|
||||
|
||||
### How IndieAuth Actually Works
|
||||
|
||||
1. **User Identity**: A user is identified by their URL (e.g., `https://alice.example.com/`)
|
||||
2. **Endpoint Discovery**: Endpoints are discovered FROM that URL
|
||||
3. **Provider Choice**: The user chooses their provider by linking to it from their profile
|
||||
4. **Dynamic Verification**: Token verification uses the discovered endpoint, not a hardcoded one
|
||||
|
||||
### Example Flow
|
||||
|
||||
When alice authenticates:
|
||||
```
|
||||
1. Alice tries to sign in with: https://alice.example.com/
|
||||
2. Client fetches https://alice.example.com/
|
||||
3. Client finds: <link rel="authorization_endpoint" href="https://auth.alice.net/auth">
|
||||
4. Client finds: <link rel="token_endpoint" href="https://auth.alice.net/token">
|
||||
5. Client uses THOSE endpoints for alice's authentication
|
||||
```
|
||||
|
||||
When bob authenticates:
|
||||
```
|
||||
1. Bob tries to sign in with: https://bob.example.org/
|
||||
2. Client fetches https://bob.example.org/
|
||||
3. Client finds: <link rel="authorization_endpoint" href="https://indieauth.com/auth">
|
||||
4. Client finds: <link rel="token_endpoint" href="https://indieauth.com/token">
|
||||
5. Client uses THOSE endpoints for bob's authentication
|
||||
```
|
||||
|
||||
**Alice and Bob use different providers, discovered from their URLs!**
|
||||
|
||||
## Decision: Correct Token Verification Architecture
|
||||
|
||||
### Token Verification Flow
|
||||
|
||||
```python
|
||||
def verify_token(token: str) -> dict:
|
||||
"""
|
||||
Verify a token using IndieAuth endpoint discovery
|
||||
|
||||
1. Get claimed 'me' URL (from token introspection or previous knowledge)
|
||||
2. Discover token endpoint from 'me' URL
|
||||
3. Verify token with discovered endpoint
|
||||
4. Validate response
|
||||
"""
|
||||
|
||||
# Step 1: Initial token introspection (if needed)
|
||||
# Some flows provide 'me' in Authorization header or token itself
|
||||
|
||||
# Step 2: Discover endpoints from user's profile URL
|
||||
endpoints = discover_endpoints(me_url)
|
||||
if not endpoints.get('token_endpoint'):
|
||||
raise Error("No token endpoint found for user")
|
||||
|
||||
# Step 3: Verify with discovered endpoint
|
||||
response = verify_with_endpoint(
|
||||
token=token,
|
||||
endpoint=endpoints['token_endpoint']
|
||||
)
|
||||
|
||||
# Step 4: Validate response
|
||||
if response['me'] != me_url:
|
||||
raise Error("Token 'me' doesn't match claimed identity")
|
||||
|
||||
return response
|
||||
```
|
||||
|
||||
### Endpoint Discovery Implementation
|
||||
|
||||
```python
|
||||
def discover_endpoints(profile_url: str) -> dict:
|
||||
"""
|
||||
Discover IndieAuth endpoints from a profile URL
|
||||
Per https://www.w3.org/TR/indieauth/#discovery-by-clients
|
||||
|
||||
Priority order:
|
||||
1. HTTP Link headers
|
||||
2. HTML <link> elements
|
||||
3. IndieAuth metadata endpoint
|
||||
"""
|
||||
|
||||
# Fetch the profile URL
|
||||
response = http_get(profile_url, headers={'Accept': 'text/html'})
|
||||
|
||||
endpoints = {}
|
||||
|
||||
# 1. Check HTTP Link headers (highest priority)
|
||||
link_header = response.headers.get('Link')
|
||||
if link_header:
|
||||
endpoints.update(parse_link_header(link_header))
|
||||
|
||||
# 2. Check HTML <link> elements
|
||||
if 'text/html' in response.headers.get('Content-Type', ''):
|
||||
soup = parse_html(response.text)
|
||||
|
||||
# Find authorization endpoint
|
||||
auth_link = soup.find('link', rel='authorization_endpoint')
|
||||
if auth_link and not endpoints.get('authorization_endpoint'):
|
||||
endpoints['authorization_endpoint'] = urljoin(
|
||||
profile_url,
|
||||
auth_link.get('href')
|
||||
)
|
||||
|
||||
# Find token endpoint
|
||||
token_link = soup.find('link', rel='token_endpoint')
|
||||
if token_link and not endpoints.get('token_endpoint'):
|
||||
endpoints['token_endpoint'] = urljoin(
|
||||
profile_url,
|
||||
token_link.get('href')
|
||||
)
|
||||
|
||||
# 3. Check IndieAuth metadata endpoint (if supported)
|
||||
# Look for rel="indieauth-metadata"
|
||||
|
||||
return endpoints
|
||||
```
|
||||
|
||||
### Caching Strategy
|
||||
|
||||
```python
|
||||
class EndpointCache:
|
||||
"""
|
||||
Cache discovered endpoints for performance
|
||||
Key insight: User's chosen endpoints rarely change
|
||||
"""
|
||||
|
||||
def __init__(self, ttl=3600): # 1 hour default
|
||||
self.cache = {} # profile_url -> (endpoints, expiry)
|
||||
self.ttl = ttl
|
||||
|
||||
def get_endpoints(self, profile_url: str) -> dict:
|
||||
"""Get endpoints, using cache if valid"""
|
||||
|
||||
if profile_url in self.cache:
|
||||
endpoints, expiry = self.cache[profile_url]
|
||||
if time.time() < expiry:
|
||||
return endpoints
|
||||
|
||||
# Discovery needed
|
||||
endpoints = discover_endpoints(profile_url)
|
||||
|
||||
# Cache for future use
|
||||
self.cache[profile_url] = (
|
||||
endpoints,
|
||||
time.time() + self.ttl
|
||||
)
|
||||
|
||||
return endpoints
|
||||
```
|
||||
|
||||
## Why This Is Correct
|
||||
|
||||
### User Sovereignty
|
||||
- Users control their authentication by choosing their provider
|
||||
- Users can switch providers by updating their profile links
|
||||
- No vendor lock-in to specific auth servers
|
||||
|
||||
### Decentralization
|
||||
- No central authority for authentication
|
||||
- Any server can be an IndieAuth provider
|
||||
- Users can self-host their auth if desired
|
||||
|
||||
### Security
|
||||
- Provider changes are immediately reflected
|
||||
- Compromised providers can be switched instantly
|
||||
- Users maintain control of their identity
|
||||
|
||||
## What Was Wrong Before
|
||||
|
||||
### The Fatal Flaw
|
||||
```ini
|
||||
# WRONG - This violates IndieAuth!
|
||||
TOKEN_ENDPOINT=https://tokens.indieauth.com/token
|
||||
```
|
||||
|
||||
This assumes ALL users use the same token endpoint. This is fundamentally incorrect because:
|
||||
|
||||
1. **Breaks user choice**: Forces everyone to use indieauth.com
|
||||
2. **Violates spec**: IndieAuth requires endpoint discovery
|
||||
3. **Security risk**: If indieauth.com is compromised, all users affected
|
||||
4. **No flexibility**: Users can't switch providers
|
||||
5. **Not IndieAuth**: This is just OAuth with a hardcoded provider
|
||||
|
||||
### The Correct Approach
|
||||
```ini
|
||||
# CORRECT - Only store the admin's identity URL
|
||||
ADMIN_ME=https://admin.example.com/
|
||||
|
||||
# Endpoints are discovered from ADMIN_ME at runtime!
|
||||
```
|
||||
|
||||
## Implementation Requirements
|
||||
|
||||
### 1. HTTP Client Requirements
|
||||
- Follow redirects (up to a limit)
|
||||
- Parse Link headers correctly
|
||||
- Handle HTML parsing
|
||||
- Respect Content-Type
|
||||
- Implement timeouts
|
||||
|
||||
### 2. URL Resolution
|
||||
- Properly resolve relative URLs
|
||||
- Handle different URL schemes
|
||||
- Normalize URLs correctly
|
||||
|
||||
### 3. Error Handling
|
||||
- Profile URL unreachable
|
||||
- No endpoints discovered
|
||||
- Invalid HTML
|
||||
- Malformed Link headers
|
||||
- Network timeouts
|
||||
|
||||
### 4. Security Considerations
|
||||
- Validate HTTPS for endpoints
|
||||
- Prevent redirect loops
|
||||
- Limit redirect chains
|
||||
- Validate discovered URLs
|
||||
- Cache poisoning prevention
|
||||
|
||||
## Configuration Changes
|
||||
|
||||
### Remove (WRONG)
|
||||
```ini
|
||||
TOKEN_ENDPOINT=https://tokens.indieauth.com/token
|
||||
AUTHORIZATION_ENDPOINT=https://indieauth.com/auth
|
||||
```
|
||||
|
||||
### Keep (CORRECT)
|
||||
```ini
|
||||
ADMIN_ME=https://admin.example.com/
|
||||
# Endpoints discovered from ADMIN_ME automatically!
|
||||
```
|
||||
|
||||
## Micropub Token Verification Flow
|
||||
|
||||
```
|
||||
1. Micropub receives request with Bearer token
|
||||
2. Extract token from Authorization header
|
||||
3. Need to verify token, but with which endpoint?
|
||||
4. Option A: If we have cached token info, use cached 'me' URL
|
||||
5. Option B: Try verification with last known endpoint for similar tokens
|
||||
6. Option C: Require 'me' parameter in Micropub request
|
||||
7. Discover token endpoint from 'me' URL
|
||||
8. Verify token with discovered endpoint
|
||||
9. Cache the verification result and endpoint
|
||||
10. Process Micropub request if valid
|
||||
```
|
||||
|
||||
## Testing Requirements
|
||||
|
||||
### Unit Tests
|
||||
- Endpoint discovery from HTML
|
||||
- Link header parsing
|
||||
- URL resolution
|
||||
- Cache behavior
|
||||
|
||||
### Integration Tests
|
||||
- Discovery from real IndieAuth providers
|
||||
- Different HTML structures
|
||||
- Various Link header formats
|
||||
- Redirect handling
|
||||
|
||||
### Test Cases
|
||||
```python
|
||||
# Test different profile configurations
|
||||
test_profiles = [
|
||||
{
|
||||
'url': 'https://user1.example.com/',
|
||||
'html': '<link rel="token_endpoint" href="https://auth.example.com/token">',
|
||||
'expected': 'https://auth.example.com/token'
|
||||
},
|
||||
{
|
||||
'url': 'https://user2.example.com/',
|
||||
'html': '<link rel="token_endpoint" href="/auth/token">', # Relative URL
|
||||
'expected': 'https://user2.example.com/auth/token'
|
||||
},
|
||||
{
|
||||
'url': 'https://user3.example.com/',
|
||||
'link_header': '<https://indieauth.com/token>; rel="token_endpoint"',
|
||||
'expected': 'https://indieauth.com/token'
|
||||
}
|
||||
]
|
||||
```
|
||||
|
||||
## Documentation Requirements
|
||||
|
||||
### User Documentation
|
||||
- Explain how to set up profile URLs
|
||||
- Show examples of link elements
|
||||
- List compatible providers
|
||||
- Troubleshooting guide
|
||||
|
||||
### Developer Documentation
|
||||
- Endpoint discovery algorithm
|
||||
- Cache implementation details
|
||||
- Error handling strategies
|
||||
- Security considerations
|
||||
|
||||
## Consequences
|
||||
|
||||
### Positive
|
||||
- **Spec Compliant**: Correctly implements IndieAuth
|
||||
- **User Freedom**: Users choose their providers
|
||||
- **Decentralized**: No hardcoded central authority
|
||||
- **Flexible**: Supports any IndieAuth provider
|
||||
- **Secure**: Provider changes take effect immediately
|
||||
|
||||
### Negative
|
||||
- **Complexity**: More complex than hardcoded endpoints
|
||||
- **Performance**: Discovery adds latency (mitigated by caching)
|
||||
- **Reliability**: Depends on profile URL availability
|
||||
- **Testing**: More complex test scenarios
|
||||
|
||||
## Alternatives Considered
|
||||
|
||||
### Alternative 1: Hardcoded Endpoints (REJECTED)
|
||||
**Why it's wrong**: Violates IndieAuth specification fundamentally
|
||||
|
||||
### Alternative 2: Configuration Per User
|
||||
**Why it's wrong**: Still not dynamic discovery, doesn't follow spec
|
||||
|
||||
### Alternative 3: Only Support One Provider
|
||||
**Why it's wrong**: Defeats the purpose of IndieAuth's decentralization
|
||||
|
||||
## References
|
||||
|
||||
- [IndieAuth Spec Section 4.2: Discovery](https://www.w3.org/TR/indieauth/#discovery-by-clients)
|
||||
- [IndieAuth Spec Section 6: Token Verification](https://www.w3.org/TR/indieauth/#token-verification)
|
||||
- [Link Header RFC 8288](https://tools.ietf.org/html/rfc8288)
|
||||
- [HTML Link Element Spec](https://html.spec.whatwg.org/multipage/semantics.html#the-link-element)
|
||||
|
||||
## Acknowledgment of Error
|
||||
|
||||
This ADR corrects a fundamental misunderstanding in the original ADR-030. The error was:
|
||||
- Recommending hardcoded token endpoints
|
||||
- Not understanding endpoint discovery
|
||||
- Missing the core principle of user sovereignty
|
||||
|
||||
The architect acknowledges this critical error and has:
|
||||
1. Re-read the IndieAuth specification thoroughly
|
||||
2. Understood the importance of endpoint discovery
|
||||
3. Designed the correct implementation
|
||||
4. Documented the proper architecture
|
||||
|
||||
---
|
||||
|
||||
**Document Version**: 2.0 (Complete Correction)
|
||||
**Created**: 2024-11-24
|
||||
**Author**: StarPunk Architecture Team
|
||||
**Note**: This completely replaces the incorrect understanding in ADR-030
|
||||
116
docs/decisions/ADR-031-endpoint-discovery-implementation.md
Normal file
116
docs/decisions/ADR-031-endpoint-discovery-implementation.md
Normal file
@@ -0,0 +1,116 @@
|
||||
# ADR-031: IndieAuth Endpoint Discovery Implementation Details
|
||||
|
||||
## Status
|
||||
Accepted
|
||||
|
||||
## Context
|
||||
|
||||
The developer raised critical implementation questions about ADR-030-CORRECTED regarding IndieAuth endpoint discovery. The primary blocker was the "chicken-and-egg" problem: when receiving a token, how do we know which endpoint to verify it with?
|
||||
|
||||
## Decision
|
||||
|
||||
For StarPunk V1 (single-user CMS), we will:
|
||||
|
||||
1. **ALWAYS use ADMIN_ME for endpoint discovery** when verifying tokens
|
||||
2. **Use simple caching structure** optimized for single-user
|
||||
3. **Add BeautifulSoup4** as a dependency for robust HTML parsing
|
||||
4. **Fail closed** on security errors with cache grace period
|
||||
5. **Allow HTTP in debug mode** for local development
|
||||
|
||||
### Core Implementation
|
||||
|
||||
```python
|
||||
def verify_external_token(token: str) -> Optional[Dict[str, Any]]:
|
||||
"""Verify token - single-user V1 implementation"""
|
||||
admin_me = current_app.config.get("ADMIN_ME")
|
||||
|
||||
# Always discover from ADMIN_ME (single-user assumption)
|
||||
endpoints = discover_endpoints(admin_me)
|
||||
token_endpoint = endpoints['token_endpoint']
|
||||
|
||||
# Verify and validate token belongs to admin
|
||||
token_info = verify_with_endpoint(token_endpoint, token)
|
||||
|
||||
if normalize_url(token_info['me']) != normalize_url(admin_me):
|
||||
raise TokenVerificationError("Token not for admin user")
|
||||
|
||||
return token_info
|
||||
```
|
||||
|
||||
## Rationale
|
||||
|
||||
### Why ADMIN_ME Discovery?
|
||||
|
||||
StarPunk V1 is explicitly single-user. Only the admin can post, so any valid token MUST belong to ADMIN_ME. This eliminates the chicken-and-egg problem entirely.
|
||||
|
||||
### Why Simple Cache?
|
||||
|
||||
With only one user, we don't need complex profile->endpoints mapping. A simple cache suffices:
|
||||
|
||||
```python
|
||||
class EndpointCache:
|
||||
def __init__(self):
|
||||
self.endpoints = None # Single user's endpoints
|
||||
self.endpoints_expire = 0
|
||||
self.token_cache = {} # token_hash -> (info, expiry)
|
||||
```
|
||||
|
||||
### Why BeautifulSoup4?
|
||||
|
||||
- Industry standard for HTML parsing
|
||||
- More robust than regex or built-in parsers
|
||||
- Pure Python implementation available
|
||||
- Worth the dependency for correctness
|
||||
|
||||
### Why Fail Closed?
|
||||
|
||||
Security principle: when in doubt, deny access. We use cached endpoints as a grace period during network failures, but ultimately deny access if we cannot verify.
|
||||
|
||||
## Consequences
|
||||
|
||||
### Positive
|
||||
- Eliminates complexity of multi-user endpoint discovery
|
||||
- Simple, clear implementation path
|
||||
- Secure by default
|
||||
- Easy to test and verify
|
||||
|
||||
### Negative
|
||||
- Will need refactoring for V2 multi-user support
|
||||
- Adds BeautifulSoup4 dependency
|
||||
- First request after cache expiry has ~850ms latency
|
||||
|
||||
### Migration Impact
|
||||
- Breaking change: TOKEN_ENDPOINT config removed
|
||||
- Users must update configuration
|
||||
- Clear deprecation warnings provided
|
||||
|
||||
## Alternatives Considered
|
||||
|
||||
### Alternative 1: Require 'me' Parameter
|
||||
**Rejected**: Would violate Micropub specification
|
||||
|
||||
### Alternative 2: Try Multiple Endpoints
|
||||
**Rejected**: Complex, slow, and unnecessary for single-user
|
||||
|
||||
### Alternative 3: Pre-warm Cache
|
||||
**Rejected**: Adds complexity for minimal benefit
|
||||
|
||||
## Implementation Timeline
|
||||
|
||||
- **v1.0.0-rc.5**: Full implementation with migration guide
|
||||
- Remove TOKEN_ENDPOINT configuration
|
||||
- Add endpoint discovery from ADMIN_ME
|
||||
- Document single-user assumption
|
||||
|
||||
## Testing Strategy
|
||||
|
||||
- Unit tests with mocked HTTP responses
|
||||
- Edge case coverage (malformed HTML, network errors)
|
||||
- One integration test with real IndieAuth.com
|
||||
- Skip real provider tests in CI (manual testing only)
|
||||
|
||||
## References
|
||||
|
||||
- W3C IndieAuth Specification Section 4.2 (Discovery)
|
||||
- ADR-030-CORRECTED (Original design)
|
||||
- Developer analysis report (2025-11-24)
|
||||
492
docs/migration/fix-hardcoded-endpoints.md
Normal file
492
docs/migration/fix-hardcoded-endpoints.md
Normal file
@@ -0,0 +1,492 @@
|
||||
# Migration Guide: Fixing Hardcoded IndieAuth Endpoints
|
||||
|
||||
## Overview
|
||||
|
||||
This guide explains how to migrate from the **incorrect** hardcoded endpoint implementation to the **correct** dynamic endpoint discovery implementation that actually follows the IndieAuth specification.
|
||||
|
||||
## The Problem We're Fixing
|
||||
|
||||
### What's Currently Wrong
|
||||
|
||||
```python
|
||||
# WRONG - auth_external.py (hypothetical incorrect implementation)
|
||||
class ExternalTokenVerifier:
|
||||
def __init__(self):
|
||||
# FATAL FLAW: Hardcoded endpoint
|
||||
self.token_endpoint = "https://tokens.indieauth.com/token"
|
||||
|
||||
def verify_token(self, token):
|
||||
# Uses hardcoded endpoint for ALL users
|
||||
response = requests.get(
|
||||
self.token_endpoint,
|
||||
headers={'Authorization': f'Bearer {token}'}
|
||||
)
|
||||
return response.json()
|
||||
```
|
||||
|
||||
### Why It's Wrong
|
||||
|
||||
1. **Not IndieAuth**: This completely violates the IndieAuth specification
|
||||
2. **No User Choice**: Forces all users to use the same provider
|
||||
3. **Security Risk**: Single point of failure for all authentications
|
||||
4. **No Flexibility**: Users can't change or choose providers
|
||||
|
||||
## The Correct Implementation
|
||||
|
||||
### Step 1: Remove Hardcoded Configuration
|
||||
|
||||
**Remove from config files:**
|
||||
|
||||
```ini
|
||||
# DELETE THESE LINES - They are wrong!
|
||||
TOKEN_ENDPOINT=https://tokens.indieauth.com/token
|
||||
AUTHORIZATION_ENDPOINT=https://indieauth.com/auth
|
||||
```
|
||||
|
||||
**Keep only:**
|
||||
|
||||
```ini
|
||||
# CORRECT - Only the admin's identity URL
|
||||
ADMIN_ME=https://admin.example.com/
|
||||
```
|
||||
|
||||
### Step 2: Implement Endpoint Discovery
|
||||
|
||||
**Create `endpoint_discovery.py`:**
|
||||
|
||||
```python
|
||||
"""
|
||||
IndieAuth Endpoint Discovery
|
||||
Implements: https://www.w3.org/TR/indieauth/#discovery-by-clients
|
||||
"""
|
||||
|
||||
import re
|
||||
from typing import Dict, Optional
|
||||
from urllib.parse import urljoin, urlparse
|
||||
import httpx
|
||||
from bs4 import BeautifulSoup
|
||||
|
||||
class EndpointDiscovery:
|
||||
"""Discovers IndieAuth endpoints from profile URLs"""
|
||||
|
||||
def __init__(self, timeout: int = 5):
|
||||
self.timeout = timeout
|
||||
self.client = httpx.Client(
|
||||
timeout=timeout,
|
||||
follow_redirects=True,
|
||||
limits=httpx.Limits(max_redirects=5)
|
||||
)
|
||||
|
||||
def discover(self, profile_url: str) -> Dict[str, str]:
|
||||
"""
|
||||
Discover IndieAuth endpoints from a profile URL
|
||||
|
||||
Args:
|
||||
profile_url: The user's profile URL (their identity)
|
||||
|
||||
Returns:
|
||||
Dictionary with 'authorization_endpoint' and 'token_endpoint'
|
||||
|
||||
Raises:
|
||||
DiscoveryError: If discovery fails
|
||||
"""
|
||||
# Ensure HTTPS in production
|
||||
if not self._is_development() and not profile_url.startswith('https://'):
|
||||
raise DiscoveryError("Profile URL must use HTTPS")
|
||||
|
||||
try:
|
||||
response = self.client.get(profile_url)
|
||||
response.raise_for_status()
|
||||
except Exception as e:
|
||||
raise DiscoveryError(f"Failed to fetch profile: {e}")
|
||||
|
||||
endpoints = {}
|
||||
|
||||
# 1. Check HTTP Link headers (highest priority)
|
||||
link_header = response.headers.get('Link', '')
|
||||
if link_header:
|
||||
endpoints.update(self._parse_link_header(link_header, profile_url))
|
||||
|
||||
# 2. Check HTML link elements
|
||||
if 'text/html' in response.headers.get('Content-Type', ''):
|
||||
endpoints.update(self._extract_from_html(
|
||||
response.text,
|
||||
profile_url
|
||||
))
|
||||
|
||||
# Validate we found required endpoints
|
||||
if 'token_endpoint' not in endpoints:
|
||||
raise DiscoveryError("No token endpoint found in profile")
|
||||
|
||||
return endpoints
|
||||
|
||||
def _parse_link_header(self, header: str, base_url: str) -> Dict[str, str]:
|
||||
"""Parse HTTP Link header for endpoints"""
|
||||
endpoints = {}
|
||||
|
||||
# Parse Link: <url>; rel="relation"
|
||||
pattern = r'<([^>]+)>;\s*rel="([^"]+)"'
|
||||
matches = re.findall(pattern, header)
|
||||
|
||||
for url, rel in matches:
|
||||
if rel == 'authorization_endpoint':
|
||||
endpoints['authorization_endpoint'] = urljoin(base_url, url)
|
||||
elif rel == 'token_endpoint':
|
||||
endpoints['token_endpoint'] = urljoin(base_url, url)
|
||||
|
||||
return endpoints
|
||||
|
||||
def _extract_from_html(self, html: str, base_url: str) -> Dict[str, str]:
|
||||
"""Extract endpoints from HTML link elements"""
|
||||
endpoints = {}
|
||||
soup = BeautifulSoup(html, 'html.parser')
|
||||
|
||||
# Find <link rel="authorization_endpoint" href="...">
|
||||
auth_link = soup.find('link', rel='authorization_endpoint')
|
||||
if auth_link and auth_link.get('href'):
|
||||
endpoints['authorization_endpoint'] = urljoin(
|
||||
base_url,
|
||||
auth_link['href']
|
||||
)
|
||||
|
||||
# Find <link rel="token_endpoint" href="...">
|
||||
token_link = soup.find('link', rel='token_endpoint')
|
||||
if token_link and token_link.get('href'):
|
||||
endpoints['token_endpoint'] = urljoin(
|
||||
base_url,
|
||||
token_link['href']
|
||||
)
|
||||
|
||||
return endpoints
|
||||
|
||||
def _is_development(self) -> bool:
|
||||
"""Check if running in development mode"""
|
||||
# Implementation depends on your config system
|
||||
return False
|
||||
|
||||
|
||||
class DiscoveryError(Exception):
|
||||
"""Raised when endpoint discovery fails"""
|
||||
pass
|
||||
```
|
||||
|
||||
### Step 3: Update Token Verification
|
||||
|
||||
**Update `auth_external.py`:**
|
||||
|
||||
```python
|
||||
"""
|
||||
External Token Verification with Dynamic Discovery
|
||||
"""
|
||||
|
||||
import hashlib
|
||||
import time
|
||||
from typing import Dict, Optional
|
||||
import httpx
|
||||
|
||||
from .endpoint_discovery import EndpointDiscovery, DiscoveryError
|
||||
|
||||
|
||||
class ExternalTokenVerifier:
|
||||
"""Verifies tokens using discovered IndieAuth endpoints"""
|
||||
|
||||
def __init__(self, admin_me: str, cache_ttl: int = 300):
|
||||
self.admin_me = admin_me
|
||||
self.discovery = EndpointDiscovery()
|
||||
self.cache = TokenCache(ttl=cache_ttl)
|
||||
|
||||
def verify_token(self, token: str) -> Dict:
|
||||
"""
|
||||
Verify a token using endpoint discovery
|
||||
|
||||
Args:
|
||||
token: Bearer token to verify
|
||||
|
||||
Returns:
|
||||
Token info dict with 'me', 'scope', 'client_id'
|
||||
|
||||
Raises:
|
||||
TokenVerificationError: If verification fails
|
||||
"""
|
||||
# Check cache first
|
||||
token_hash = self._hash_token(token)
|
||||
cached = self.cache.get(token_hash)
|
||||
if cached:
|
||||
return cached
|
||||
|
||||
# Discover endpoints for admin
|
||||
try:
|
||||
endpoints = self.discovery.discover(self.admin_me)
|
||||
except DiscoveryError as e:
|
||||
raise TokenVerificationError(f"Endpoint discovery failed: {e}")
|
||||
|
||||
# Verify with discovered endpoint
|
||||
token_endpoint = endpoints['token_endpoint']
|
||||
|
||||
try:
|
||||
response = httpx.get(
|
||||
token_endpoint,
|
||||
headers={'Authorization': f'Bearer {token}'},
|
||||
timeout=5.0
|
||||
)
|
||||
response.raise_for_status()
|
||||
except Exception as e:
|
||||
raise TokenVerificationError(f"Token verification failed: {e}")
|
||||
|
||||
token_info = response.json()
|
||||
|
||||
# Validate response
|
||||
if 'me' not in token_info:
|
||||
raise TokenVerificationError("Invalid token response: missing 'me'")
|
||||
|
||||
# Ensure token is for our admin
|
||||
if self._normalize_url(token_info['me']) != self._normalize_url(self.admin_me):
|
||||
raise TokenVerificationError(
|
||||
f"Token is for {token_info['me']}, expected {self.admin_me}"
|
||||
)
|
||||
|
||||
# Check scope
|
||||
scopes = token_info.get('scope', '').split()
|
||||
if 'create' not in scopes:
|
||||
raise TokenVerificationError("Token missing 'create' scope")
|
||||
|
||||
# Cache successful verification
|
||||
self.cache.store(token_hash, token_info)
|
||||
|
||||
return token_info
|
||||
|
||||
def _hash_token(self, token: str) -> str:
|
||||
"""Hash token for secure caching"""
|
||||
return hashlib.sha256(token.encode()).hexdigest()
|
||||
|
||||
def _normalize_url(self, url: str) -> str:
|
||||
"""Normalize URL for comparison"""
|
||||
# Add trailing slash if missing
|
||||
if not url.endswith('/'):
|
||||
url += '/'
|
||||
return url.lower()
|
||||
|
||||
|
||||
class TokenCache:
|
||||
"""Simple in-memory cache for token verifications"""
|
||||
|
||||
def __init__(self, ttl: int = 300):
|
||||
self.ttl = ttl
|
||||
self.cache = {}
|
||||
|
||||
def get(self, token_hash: str) -> Optional[Dict]:
|
||||
"""Get cached token info if still valid"""
|
||||
if token_hash in self.cache:
|
||||
info, expiry = self.cache[token_hash]
|
||||
if time.time() < expiry:
|
||||
return info
|
||||
else:
|
||||
del self.cache[token_hash]
|
||||
return None
|
||||
|
||||
def store(self, token_hash: str, info: Dict):
|
||||
"""Cache token info"""
|
||||
expiry = time.time() + self.ttl
|
||||
self.cache[token_hash] = (info, expiry)
|
||||
|
||||
|
||||
class TokenVerificationError(Exception):
|
||||
"""Raised when token verification fails"""
|
||||
pass
|
||||
```
|
||||
|
||||
### Step 4: Update Micropub Integration
|
||||
|
||||
**Update Micropub to use discovery-based verification:**
|
||||
|
||||
```python
|
||||
# micropub.py
|
||||
from ..auth.auth_external import ExternalTokenVerifier
|
||||
|
||||
class MicropubEndpoint:
|
||||
def __init__(self, config):
|
||||
self.verifier = ExternalTokenVerifier(
|
||||
admin_me=config['ADMIN_ME'],
|
||||
cache_ttl=config.get('TOKEN_CACHE_TTL', 300)
|
||||
)
|
||||
|
||||
def handle_request(self, request):
|
||||
# Extract token
|
||||
auth_header = request.headers.get('Authorization', '')
|
||||
if not auth_header.startswith('Bearer '):
|
||||
return error_response(401, "No bearer token provided")
|
||||
|
||||
token = auth_header[7:] # Remove 'Bearer ' prefix
|
||||
|
||||
# Verify using discovery
|
||||
try:
|
||||
token_info = self.verifier.verify_token(token)
|
||||
except TokenVerificationError as e:
|
||||
return error_response(403, str(e))
|
||||
|
||||
# Process Micropub request
|
||||
# ...
|
||||
```
|
||||
|
||||
## Migration Steps
|
||||
|
||||
### Phase 1: Preparation
|
||||
|
||||
1. **Review current implementation**
|
||||
- Identify all hardcoded endpoint references
|
||||
- Document current configuration
|
||||
|
||||
2. **Set up test environment**
|
||||
- Create test profile with IndieAuth links
|
||||
- Set up test IndieAuth provider
|
||||
|
||||
3. **Write tests for new implementation**
|
||||
- Unit tests for discovery
|
||||
- Integration tests for verification
|
||||
|
||||
### Phase 2: Implementation
|
||||
|
||||
1. **Implement discovery module**
|
||||
- Create endpoint_discovery.py
|
||||
- Add comprehensive error handling
|
||||
- Include logging for debugging
|
||||
|
||||
2. **Update token verification**
|
||||
- Remove hardcoded endpoints
|
||||
- Integrate discovery module
|
||||
- Add caching layer
|
||||
|
||||
3. **Update configuration**
|
||||
- Remove TOKEN_ENDPOINT from config
|
||||
- Ensure ADMIN_ME is set correctly
|
||||
|
||||
### Phase 3: Testing
|
||||
|
||||
1. **Test discovery with various providers**
|
||||
- indieauth.com
|
||||
- Self-hosted IndieAuth
|
||||
- Custom implementations
|
||||
|
||||
2. **Test error conditions**
|
||||
- Profile URL unreachable
|
||||
- No endpoints in profile
|
||||
- Invalid token responses
|
||||
|
||||
3. **Performance testing**
|
||||
- Measure discovery latency
|
||||
- Verify cache effectiveness
|
||||
- Test under load
|
||||
|
||||
### Phase 4: Deployment
|
||||
|
||||
1. **Update documentation**
|
||||
- Explain endpoint discovery
|
||||
- Provide setup instructions
|
||||
- Include troubleshooting guide
|
||||
|
||||
2. **Deploy to staging**
|
||||
- Test with real IndieAuth providers
|
||||
- Monitor for issues
|
||||
- Verify performance
|
||||
|
||||
3. **Deploy to production**
|
||||
- Clear any existing caches
|
||||
- Monitor closely for first 24 hours
|
||||
- Be ready to roll back if needed
|
||||
|
||||
## Verification Checklist
|
||||
|
||||
After migration, verify:
|
||||
|
||||
- [ ] No hardcoded endpoints remain in code
|
||||
- [ ] Discovery works with test profiles
|
||||
- [ ] Token verification uses discovered endpoints
|
||||
- [ ] Cache improves performance
|
||||
- [ ] Error messages are clear
|
||||
- [ ] Logs contain useful debugging info
|
||||
- [ ] Documentation is updated
|
||||
- [ ] Tests pass
|
||||
|
||||
## Troubleshooting
|
||||
|
||||
### Common Issues
|
||||
|
||||
#### "No token endpoint found"
|
||||
|
||||
**Cause**: Profile URL doesn't have IndieAuth links
|
||||
|
||||
**Solution**:
|
||||
1. Check profile URL returns HTML
|
||||
2. Verify link elements are present
|
||||
3. Check for typos in rel attributes
|
||||
|
||||
#### "Token verification failed"
|
||||
|
||||
**Cause**: Various issues with endpoint or token
|
||||
|
||||
**Solution**:
|
||||
1. Check endpoint is reachable
|
||||
2. Verify token hasn't expired
|
||||
3. Ensure 'me' URL matches expected
|
||||
|
||||
#### "Discovery timeout"
|
||||
|
||||
**Cause**: Profile URL slow or unreachable
|
||||
|
||||
**Solution**:
|
||||
1. Increase timeout if needed
|
||||
2. Check network connectivity
|
||||
3. Verify profile URL is correct
|
||||
|
||||
## Rollback Plan
|
||||
|
||||
If issues arise:
|
||||
|
||||
1. **Keep old code available**
|
||||
- Tag release before migration
|
||||
- Keep backup of old implementation
|
||||
|
||||
2. **Quick rollback procedure**
|
||||
```bash
|
||||
# Revert to previous version
|
||||
git checkout tags/pre-discovery-migration
|
||||
|
||||
# Restore old configuration
|
||||
cp config.ini.backup config.ini
|
||||
|
||||
# Restart application
|
||||
systemctl restart starpunk
|
||||
```
|
||||
|
||||
3. **Document issues for retry**
|
||||
- What failed?
|
||||
- Error messages
|
||||
- Affected users
|
||||
|
||||
## Success Criteria
|
||||
|
||||
Migration is successful when:
|
||||
|
||||
1. All token verifications use discovered endpoints
|
||||
2. No hardcoded endpoints remain
|
||||
3. Performance is acceptable (< 500ms uncached)
|
||||
4. All tests pass
|
||||
5. Documentation is complete
|
||||
6. Users can authenticate successfully
|
||||
|
||||
## Long-term Benefits
|
||||
|
||||
After this migration:
|
||||
|
||||
1. **True IndieAuth Compliance**: Finally following the specification
|
||||
2. **User Freedom**: Users control their authentication
|
||||
3. **Better Security**: No single point of failure
|
||||
4. **Future Proof**: Ready for new IndieAuth providers
|
||||
5. **Maintainable**: Cleaner, spec-compliant code
|
||||
|
||||
---
|
||||
|
||||
**Document Version**: 1.0
|
||||
**Created**: 2024-11-24
|
||||
**Purpose**: Fix critical IndieAuth implementation error
|
||||
**Priority**: CRITICAL - Must be fixed before V1 release
|
||||
807
docs/reports/2025-11-24-endpoint-discovery-analysis.md
Normal file
807
docs/reports/2025-11-24-endpoint-discovery-analysis.md
Normal file
@@ -0,0 +1,807 @@
|
||||
# IndieAuth Endpoint Discovery Implementation Analysis
|
||||
|
||||
**Date**: 2025-11-24
|
||||
**Developer**: StarPunk Fullstack Developer
|
||||
**Status**: Ready for Architect Review
|
||||
**Target Version**: 1.0.0-rc.5
|
||||
|
||||
---
|
||||
|
||||
## Executive Summary
|
||||
|
||||
I have reviewed the architect's corrected IndieAuth endpoint discovery design and the W3C IndieAuth specification. The design is fundamentally sound and correctly implements the IndieAuth specification. However, I have **critical questions** about implementation details, particularly around the "chicken-and-egg" problem of determining which endpoint to verify a token with when we don't know the user's identity beforehand.
|
||||
|
||||
**Overall Assessment**: The design is architecturally correct, but needs clarification on practical implementation details before coding can begin.
|
||||
|
||||
---
|
||||
|
||||
## What I Understand
|
||||
|
||||
### 1. The Core Problem Fixed
|
||||
|
||||
The architect correctly identified that **hardcoding `TOKEN_ENDPOINT=https://tokens.indieauth.com/token` is fundamentally wrong**. This violates IndieAuth's core principle of user sovereignty.
|
||||
|
||||
**Correct Approach**:
|
||||
- Store only `ADMIN_ME=https://admin.example.com/` in configuration
|
||||
- Discover endpoints dynamically from the user's profile URL at runtime
|
||||
- Each user can use their own IndieAuth provider
|
||||
|
||||
### 2. Endpoint Discovery Flow
|
||||
|
||||
Per W3C IndieAuth Section 4.2, I understand the discovery process:
|
||||
|
||||
```
|
||||
1. Fetch user's profile URL (e.g., https://admin.example.com/)
|
||||
2. Check in priority order:
|
||||
a. HTTP Link headers (highest priority)
|
||||
b. HTML <link> elements (document order)
|
||||
c. IndieAuth metadata endpoint (optional)
|
||||
3. Parse rel="authorization_endpoint" and rel="token_endpoint"
|
||||
4. Resolve relative URLs against profile URL base
|
||||
5. Cache discovered endpoints (with TTL)
|
||||
```
|
||||
|
||||
**Example Discovery**:
|
||||
```html
|
||||
GET https://admin.example.com/ HTTP/1.1
|
||||
|
||||
HTTP/1.1 200 OK
|
||||
Link: <https://auth.example.com/token>; rel="token_endpoint"
|
||||
Content-Type: text/html
|
||||
|
||||
<html>
|
||||
<head>
|
||||
<link rel="authorization_endpoint" href="https://auth.example.com/authorize">
|
||||
<link rel="token_endpoint" href="https://auth.example.com/token">
|
||||
</head>
|
||||
```
|
||||
|
||||
### 3. Token Verification Flow
|
||||
|
||||
Per W3C IndieAuth Section 6, I understand token verification:
|
||||
|
||||
```
|
||||
1. Receive Bearer token in Authorization header
|
||||
2. Make GET request to token endpoint with Bearer token
|
||||
3. Token endpoint returns: {me, client_id, scope}
|
||||
4. Validate 'me' matches expected identity
|
||||
5. Check required scopes present
|
||||
```
|
||||
|
||||
**Example Verification**:
|
||||
```
|
||||
GET https://auth.example.com/token HTTP/1.1
|
||||
Authorization: Bearer xyz123
|
||||
Accept: application/json
|
||||
|
||||
HTTP/1.1 200 OK
|
||||
Content-Type: application/json
|
||||
|
||||
{
|
||||
"me": "https://admin.example.com/",
|
||||
"client_id": "https://quill.p3k.io/",
|
||||
"scope": "create update delete"
|
||||
}
|
||||
```
|
||||
|
||||
### 4. Security Considerations
|
||||
|
||||
I understand the security model from the architect's docs:
|
||||
|
||||
- **HTTPS Required**: Profile URLs and endpoints MUST use HTTPS in production
|
||||
- **Redirect Limits**: Maximum 5 redirects to prevent loops
|
||||
- **Cache Integrity**: Validate endpoints before caching
|
||||
- **URL Validation**: Ensure discovered URLs are well-formed
|
||||
- **Token Hashing**: Hash tokens before caching (SHA-256)
|
||||
|
||||
### 5. Implementation Components
|
||||
|
||||
I understand these modules need to be created:
|
||||
|
||||
1. **`endpoint_discovery.py`**: Discover endpoints from profile URLs
|
||||
- HTTP Link header parsing
|
||||
- HTML link element extraction
|
||||
- URL resolution (relative to absolute)
|
||||
- Error handling
|
||||
|
||||
2. **Updated `auth_external.py`**: Token verification with discovery
|
||||
- Integrate endpoint discovery
|
||||
- Cache discovered endpoints
|
||||
- Verify tokens with discovered endpoints
|
||||
- Validate responses
|
||||
|
||||
3. **`endpoint_cache.py`** (or part of auth_external): Caching layer
|
||||
- Endpoint caching (TTL: 3600s)
|
||||
- Token verification caching (TTL: 300s)
|
||||
- Cache invalidation
|
||||
|
||||
### 6. Current Broken Code
|
||||
|
||||
From `starpunk/auth_external.py` line 49:
|
||||
```python
|
||||
token_endpoint = current_app.config.get("TOKEN_ENDPOINT")
|
||||
```
|
||||
|
||||
This hardcoded approach is the problem we're fixing.
|
||||
|
||||
---
|
||||
|
||||
## Critical Questions for the Architect
|
||||
|
||||
### Question 1: The "Which Endpoint?" Problem ⚠️
|
||||
|
||||
**The Problem**: When Micropub receives a token, we need to verify it. But **which endpoint do we use to verify it**?
|
||||
|
||||
The W3C spec says:
|
||||
> "GET request to the token endpoint containing an HTTP Authorization header with the Bearer Token according to [[RFC6750]]"
|
||||
|
||||
But it doesn't say **how we know which token endpoint to use** when we receive a token from an unknown source.
|
||||
|
||||
**Current Micropub Flow**:
|
||||
```python
|
||||
# micropub.py line 74
|
||||
token_info = verify_external_token(token)
|
||||
```
|
||||
|
||||
The token is an opaque string like `"abc123xyz"`. We have no idea:
|
||||
- Which user it belongs to
|
||||
- Which provider issued it
|
||||
- Which endpoint to verify it with
|
||||
|
||||
**ADR-030-CORRECTED suggests (line 204-258)**:
|
||||
```
|
||||
4. Option A: If we have cached token info, use cached 'me' URL
|
||||
5. Option B: Try verification with last known endpoint for similar tokens
|
||||
6. Option C: Require 'me' parameter in Micropub request
|
||||
```
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**1a)** Which option should I implement? The ADR presents three options but doesn't specify which one.
|
||||
|
||||
**1b)** For **Option A** (cached token): How does the first request work? We need to verify a token to cache its 'me' URL, but we need the 'me' URL to know which endpoint to verify with. This is circular.
|
||||
|
||||
**1c)** For **Option B** (last known endpoint): How do we handle the first token ever received? What is the "last known endpoint" when the cache is empty?
|
||||
|
||||
**1d)** For **Option C** (require 'me' parameter): Does this violate the Micropub spec? The W3C Micropub specification doesn't include a 'me' parameter in requests. Is this a StarPunk-specific extension?
|
||||
|
||||
**1e)** **Proposed Solution** (awaiting architect approval):
|
||||
|
||||
Since StarPunk is a **single-user CMS**, we KNOW the only valid tokens are for `ADMIN_ME`. Therefore:
|
||||
|
||||
```python
|
||||
def verify_external_token(token: str) -> Optional[Dict[str, Any]]:
|
||||
"""Verify token for the admin user"""
|
||||
admin_me = current_app.config.get("ADMIN_ME")
|
||||
|
||||
# Discover endpoints from ADMIN_ME
|
||||
endpoints = discover_endpoints(admin_me)
|
||||
token_endpoint = endpoints['token_endpoint']
|
||||
|
||||
# Verify token with discovered endpoint
|
||||
response = httpx.get(
|
||||
token_endpoint,
|
||||
headers={'Authorization': f'Bearer {token}'}
|
||||
)
|
||||
|
||||
token_info = response.json()
|
||||
|
||||
# Validate token belongs to admin
|
||||
if normalize_url(token_info['me']) != normalize_url(admin_me):
|
||||
raise TokenVerificationError("Token not for admin user")
|
||||
|
||||
return token_info
|
||||
```
|
||||
|
||||
**Is this the correct approach?** This assumes:
|
||||
- StarPunk only accepts tokens for `ADMIN_ME`
|
||||
- We always discover from `ADMIN_ME` profile URL
|
||||
- Multi-user support is explicitly out of scope for V1
|
||||
|
||||
Please confirm this is correct or provide the proper approach.
|
||||
|
||||
---
|
||||
|
||||
### Question 2: Caching Strategy Details
|
||||
|
||||
**ADR-030-CORRECTED suggests** (line 131-160):
|
||||
- Endpoint cache TTL: 3600s (1 hour)
|
||||
- Token verification cache TTL: 300s (5 minutes)
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**2a)** **Cache Key for Endpoints**: Should the cache key be the profile URL (`admin_me`) or should we maintain a global cache?
|
||||
|
||||
For single-user StarPunk, we only have one profile URL (`ADMIN_ME`), so a simple cache like:
|
||||
```python
|
||||
self.cached_endpoints = None
|
||||
self.cached_until = 0
|
||||
```
|
||||
|
||||
Would suffice. Is this acceptable, or should I implement a full `profile_url -> endpoints` dict for future multi-user support?
|
||||
|
||||
**2b)** **Cache Key for Tokens**: The migration guide (line 259) suggests hashing tokens:
|
||||
```python
|
||||
token_hash = hashlib.sha256(token.encode()).hexdigest()
|
||||
```
|
||||
|
||||
But if tokens are opaque and unpredictable, why hash them? Is this:
|
||||
- To prevent tokens appearing in logs/debug output?
|
||||
- To prevent tokens being extracted from memory dumps?
|
||||
- Because cache keys should be fixed-length?
|
||||
|
||||
If it's for security, should I also:
|
||||
- Use a constant-time comparison for token hash lookups?
|
||||
- Add HMAC with a secret key instead of plain SHA-256?
|
||||
|
||||
**2c)** **Cache Invalidation**: When should I clear the cache?
|
||||
- On application startup? (cache is in-memory, so yes?)
|
||||
- On configuration changes? (how do I detect these?)
|
||||
- On token verification failures? (what if it's a network issue, not a provider change?)
|
||||
- Manual admin endpoint `/admin/clear-cache`? (should I implement this?)
|
||||
|
||||
**2d)** **Cache Storage**: The ADR shows in-memory caching. Should I:
|
||||
- Use a simple dict with tuples: `cache[key] = (value, expiry)`
|
||||
- Use `functools.lru_cache` decorator?
|
||||
- Use `cachetools` library for TTL support?
|
||||
- Implement custom `EndpointCache` class as shown in ADR?
|
||||
|
||||
For V1 simplicity, I propose **custom class with simple dict**, but please confirm.
|
||||
|
||||
---
|
||||
|
||||
### Question 3: HTML Parsing Implementation
|
||||
|
||||
**From `docs/migration/fix-hardcoded-endpoints.md`** line 139-159:
|
||||
|
||||
```python
|
||||
from bs4 import BeautifulSoup
|
||||
|
||||
def _extract_from_html(self, html: str, base_url: str) -> Dict[str, str]:
|
||||
soup = BeautifulSoup(html, 'html.parser')
|
||||
|
||||
auth_link = soup.find('link', rel='authorization_endpoint')
|
||||
if auth_link and auth_link.get('href'):
|
||||
endpoints['authorization_endpoint'] = urljoin(base_url, auth_link['href'])
|
||||
```
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**3a)** **Dependency**: Do we want to add BeautifulSoup4 as a dependency? Current dependencies (from quick check):
|
||||
- Flask
|
||||
- httpx
|
||||
- Other core libs
|
||||
|
||||
BeautifulSoup4 is a new dependency. Alternatives:
|
||||
- Use Python's built-in `html.parser` (more fragile)
|
||||
- Use regex (bad for HTML, but endpoints are simple)
|
||||
- Use `lxml` (faster, but C extension dependency)
|
||||
|
||||
**Recommendation**: Add BeautifulSoup4 with html.parser backend (pure Python). Confirm?
|
||||
|
||||
**3b)** **HTML Validation**: Should I validate HTML before parsing?
|
||||
- Malformed HTML could cause parsing errors
|
||||
- Should I catch and handle `ParserError`?
|
||||
- What if there's no `<head>` section?
|
||||
- What if `<link>` elements are in `<body>` (technically invalid but might exist)?
|
||||
|
||||
**3c)** **Case Sensitivity**: HTML `rel` attributes are case-insensitive per spec. Should I:
|
||||
```python
|
||||
soup.find('link', rel='token_endpoint') # Exact match
|
||||
# vs
|
||||
soup.find('link', rel=lambda x: x.lower() == 'token_endpoint' if x else False)
|
||||
```
|
||||
|
||||
BeautifulSoup's `find()` is case-insensitive by default for attributes, so this should be fine, but confirm?
|
||||
|
||||
---
|
||||
|
||||
### Question 4: HTTP Link Header Parsing
|
||||
|
||||
**From `docs/migration/fix-hardcoded-endpoints.md`** line 126-136:
|
||||
|
||||
```python
|
||||
def _parse_link_header(self, header: str, base_url: str) -> Dict[str, str]:
|
||||
pattern = r'<([^>]+)>;\s*rel="([^"]+)"'
|
||||
matches = re.findall(pattern, header)
|
||||
```
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**4a)** **Regex Robustness**: This regex assumes:
|
||||
- Double quotes around rel value
|
||||
- Semicolon separator
|
||||
- No spaces in weird places
|
||||
|
||||
But HTTP Link header format (RFC 8288) is more complex:
|
||||
```
|
||||
Link: <url>; rel="value"; param="other"
|
||||
Link: <url>; rel=value (no quotes allowed per spec)
|
||||
Link: <url>;rel="value" (no space after semicolon)
|
||||
```
|
||||
|
||||
Should I:
|
||||
- Use a more robust regex?
|
||||
- Use a proper Link header parser library (e.g., `httpx` has built-in parsing)?
|
||||
- Stick with simple regex and document limitations?
|
||||
|
||||
**Recommendation**: Use `httpx.Headers` built-in Link header parsing if available, otherwise simple regex. Confirm?
|
||||
|
||||
**4b)** **Multiple Headers**: RFC 8288 allows multiple Link headers:
|
||||
```
|
||||
Link: <https://auth.example.com/authorize>; rel="authorization_endpoint"
|
||||
Link: <https://auth.example.com/token>; rel="token_endpoint"
|
||||
```
|
||||
|
||||
Or comma-separated in single header:
|
||||
```
|
||||
Link: <https://auth.example.com/authorize>; rel="authorization_endpoint", <https://auth.example.com/token>; rel="token_endpoint"
|
||||
```
|
||||
|
||||
My regex with `re.findall()` should handle both. Confirm this is correct?
|
||||
|
||||
**4c)** **Priority Order**: ADR says "HTTP Link headers take precedence over HTML". But what if:
|
||||
- Link header has `authorization_endpoint` but not `token_endpoint`
|
||||
- HTML has both
|
||||
|
||||
Should I:
|
||||
```python
|
||||
# Option A: Once we find in Link header, stop looking
|
||||
if 'token_endpoint' in link_header_endpoints:
|
||||
return link_header_endpoints
|
||||
else:
|
||||
check_html()
|
||||
|
||||
# Option B: Merge Link header and HTML, Link header wins for conflicts
|
||||
endpoints = html_endpoints.copy()
|
||||
endpoints.update(link_header_endpoints) # Link header overwrites
|
||||
```
|
||||
|
||||
The W3C spec says "first HTTP Link header takes precedence", which suggests **Option B** (merge and overwrite). Confirm?
|
||||
|
||||
---
|
||||
|
||||
### Question 5: URL Resolution and Validation
|
||||
|
||||
**From ADR-030-CORRECTED** line 217:
|
||||
|
||||
```python
|
||||
from urllib.parse import urljoin
|
||||
|
||||
endpoints['token_endpoint'] = urljoin(profile_url, href)
|
||||
```
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**5a)** **URL Validation**: Should I validate discovered URLs? Checks:
|
||||
- Must be absolute after resolution
|
||||
- Must use HTTPS (in production)
|
||||
- Must be valid URL format
|
||||
- Hostname must be valid
|
||||
- No localhost/127.0.0.1 in production (allow in dev?)
|
||||
|
||||
Example validation:
|
||||
```python
|
||||
def validate_endpoint_url(url: str, is_production: bool) -> bool:
|
||||
parsed = urlparse(url)
|
||||
|
||||
if is_production and parsed.scheme != 'https':
|
||||
raise DiscoveryError("HTTPS required in production")
|
||||
|
||||
if is_production and parsed.hostname in ['localhost', '127.0.0.1', '::1']:
|
||||
raise DiscoveryError("localhost not allowed in production")
|
||||
|
||||
if not parsed.scheme or not parsed.netloc:
|
||||
raise DiscoveryError("Invalid URL format")
|
||||
|
||||
return True
|
||||
```
|
||||
|
||||
Is this overkill, or necessary? What validation do you want?
|
||||
|
||||
**5b)** **URL Normalization**: Should I normalize URLs before comparing?
|
||||
```python
|
||||
def normalize_url(url: str) -> str:
|
||||
# Add trailing slash?
|
||||
# Convert to lowercase?
|
||||
# Remove default ports?
|
||||
# Sort query params?
|
||||
```
|
||||
|
||||
The current code does:
|
||||
```python
|
||||
# auth_external.py line 96
|
||||
token_me = token_info["me"].rstrip("/")
|
||||
expected_me = admin_me.rstrip("/")
|
||||
```
|
||||
|
||||
Should endpoint URLs also be normalized? Or left as-is?
|
||||
|
||||
**5c)** **Relative URL Edge Cases**: What should happen with these?
|
||||
|
||||
```html
|
||||
<!-- Relative path -->
|
||||
<link rel="token_endpoint" href="/auth/token">
|
||||
Result: https://admin.example.com/auth/token
|
||||
|
||||
<!-- Protocol-relative -->
|
||||
<link rel="token_endpoint" href="//other-domain.com/token">
|
||||
Result: https://other-domain.com/token (if profile was HTTPS)
|
||||
|
||||
<!-- No protocol -->
|
||||
<link rel="token_endpoint" href="other-domain.com/token">
|
||||
Result: https://admin.example.com/other-domain.com/token (broken!)
|
||||
```
|
||||
|
||||
Python's `urljoin()` handles first two correctly. Third is ambiguous. Should I:
|
||||
- Reject URLs without `://` or leading `/`?
|
||||
- Try to detect and fix common mistakes?
|
||||
- Document expected format and let it fail?
|
||||
|
||||
---
|
||||
|
||||
### Question 6: Error Handling and Retry Logic
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**6a)** **Discovery Failures**: When endpoint discovery fails, what should happen?
|
||||
|
||||
Scenarios:
|
||||
1. Profile URL unreachable (DNS failure, network timeout)
|
||||
2. Profile URL returns 404/500
|
||||
3. Profile HTML malformed (parsing fails)
|
||||
4. No endpoints found in profile
|
||||
5. Endpoints found but invalid URLs
|
||||
|
||||
For each scenario, should I:
|
||||
- Return error immediately?
|
||||
- Retry with backoff?
|
||||
- Use cached endpoints if available (even if expired)?
|
||||
- Fail open (allow access) or fail closed (deny access)?
|
||||
|
||||
**Recommendation**: Fail closed (deny access), use cached endpoints if available, no retries for discovery (but retries for token verification?). Confirm?
|
||||
|
||||
**6b)** **Token Verification Failures**: When token verification fails, what should happen?
|
||||
|
||||
Scenarios:
|
||||
1. Token endpoint unreachable (timeout)
|
||||
2. Token endpoint returns 400/401/403 (token invalid)
|
||||
3. Token endpoint returns 500 (server error)
|
||||
4. Token response missing required fields
|
||||
5. Token 'me' doesn't match expected
|
||||
|
||||
For scenarios 1 and 3 (network/server errors), should I:
|
||||
- Retry with backoff?
|
||||
- Use cached token info if available?
|
||||
- Fail immediately?
|
||||
|
||||
**Recommendation**: Retry up to 3 times with exponential backoff for network errors (1, 3). For invalid tokens (2, 4, 5), fail immediately. Confirm?
|
||||
|
||||
**6c)** **Timeout Configuration**: What timeouts should I use?
|
||||
|
||||
Suggested:
|
||||
- Profile URL fetch: 5s (discovery is cached, so can be slow)
|
||||
- Token verification: 3s (happens on every request, must be fast)
|
||||
- Cache lookup: <1ms (in-memory)
|
||||
|
||||
Are these acceptable? Should they be configurable?
|
||||
|
||||
---
|
||||
|
||||
### Question 7: Testing Strategy
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**7a)** **Mock vs Real**: Should tests:
|
||||
- Mock all HTTP requests (faster, isolated)
|
||||
- Hit real IndieAuth providers (slow, integration test)
|
||||
- Both (unit tests mock, integration tests real)?
|
||||
|
||||
**Recommendation**: Unit tests mock everything, add one integration test for real IndieAuth.com. Confirm?
|
||||
|
||||
**7b)** **Test Fixtures**: Should I create test fixtures like:
|
||||
|
||||
```python
|
||||
# tests/fixtures/profiles.py
|
||||
PROFILE_WITH_LINK_HEADERS = {
|
||||
'url': 'https://user.example.com/',
|
||||
'headers': {
|
||||
'Link': '<https://auth.example.com/token>; rel="token_endpoint"'
|
||||
},
|
||||
'expected': {'token_endpoint': 'https://auth.example.com/token'}
|
||||
}
|
||||
|
||||
PROFILE_WITH_HTML_LINKS = {
|
||||
'url': 'https://user.example.com/',
|
||||
'html': '<link rel="token_endpoint" href="https://auth.example.com/token">',
|
||||
'expected': {'token_endpoint': 'https://auth.example.com/token'}
|
||||
}
|
||||
|
||||
# ... more fixtures
|
||||
```
|
||||
|
||||
Or inline test data in test functions? Fixtures would be reusable across tests.
|
||||
|
||||
**7c)** **Test Coverage**: What coverage % is acceptable? Current test suite has 501 passing tests. I should aim for:
|
||||
- 100% coverage of new endpoint discovery code?
|
||||
- Edge cases covered (malformed HTML, network errors, etc.)?
|
||||
- Integration tests for full flow?
|
||||
|
||||
---
|
||||
|
||||
### Question 8: Performance Implications
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**8a)** **First Request Latency**: Without cached endpoints, first Micropub request will:
|
||||
1. Fetch profile URL (HTTP GET): ~100-500ms
|
||||
2. Parse HTML/headers: ~10-50ms
|
||||
3. Verify token with endpoint: ~100-300ms
|
||||
4. Total: ~200-850ms
|
||||
|
||||
Is this acceptable? User will notice delay on first post. Should I:
|
||||
- Pre-warm cache on application startup?
|
||||
- Show "Authenticating..." message to user?
|
||||
- Accept the delay (only happens once per TTL)?
|
||||
|
||||
**8b)** **Cache Hit Rate**: With TTL of 3600s for endpoints and 300s for tokens:
|
||||
- Endpoints discovered once per hour
|
||||
- Tokens verified every 5 minutes
|
||||
|
||||
For active user posting frequently:
|
||||
- First post: 850ms (discovery + verification)
|
||||
- Posts within 5 min: <1ms (cached token)
|
||||
- Posts after 5 min but within 1 hour: ~150ms (cached endpoint, verify token)
|
||||
- Posts after 1 hour: 850ms again
|
||||
|
||||
Is this acceptable? Or should I increase token cache TTL?
|
||||
|
||||
**8c)** **Concurrent Requests**: If two Micropub requests arrive simultaneously with uncached token:
|
||||
- Both will trigger endpoint discovery
|
||||
- Race condition in cache update
|
||||
|
||||
Should I:
|
||||
- Add locking around cache updates?
|
||||
- Accept duplicate discoveries (harmless, just wasteful)?
|
||||
- Use thread-safe cache implementation?
|
||||
|
||||
**Recommendation**: For V1 single-user CMS with low traffic, accept duplicates. Add locking in V2+ if needed.
|
||||
|
||||
---
|
||||
|
||||
### Question 9: Configuration and Deployment
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**9a)** **Configuration Changes**: Current config has:
|
||||
```ini
|
||||
# .env (WRONG - to be removed)
|
||||
TOKEN_ENDPOINT=https://tokens.indieauth.com/token
|
||||
|
||||
# .env (CORRECT - to be kept)
|
||||
ADMIN_ME=https://admin.example.com/
|
||||
```
|
||||
|
||||
Should I:
|
||||
- Remove `TOKEN_ENDPOINT` from config.py immediately?
|
||||
- Add deprecation warning if `TOKEN_ENDPOINT` is set?
|
||||
- Provide migration instructions in CHANGELOG?
|
||||
|
||||
**9b)** **Backward Compatibility**: RC.4 was just released with `TOKEN_ENDPOINT` configuration. RC.5 will remove it. Should I:
|
||||
- Provide migration script?
|
||||
- Automatic migration (detect and convert)?
|
||||
- Just document breaking change in CHANGELOG?
|
||||
|
||||
Since we're in RC phase, breaking changes are acceptable, but users might be testing. Recommendation?
|
||||
|
||||
**9c)** **Health Check**: Should the `/health` endpoint also check:
|
||||
- Endpoint discovery working (fetch ADMIN_ME profile)?
|
||||
- Token endpoint reachable?
|
||||
|
||||
Or is this too expensive for health checks?
|
||||
|
||||
---
|
||||
|
||||
### Question 10: Development and Testing Workflow
|
||||
|
||||
**My Questions**:
|
||||
|
||||
**10a)** **Local Development**: Developers typically use `http://localhost:5000` for SITE_URL. But IndieAuth requires HTTPS. How should developers test?
|
||||
|
||||
Options:
|
||||
1. Allow HTTP in development mode (detect DEV_MODE=true)
|
||||
2. Require ngrok/localhost.run for HTTPS tunneling
|
||||
3. Use mock endpoints in dev mode
|
||||
4. Accept that IndieAuth won't work locally without setup
|
||||
|
||||
Current `auth_external.py` doesn't have HTTPS check. Should I add it with dev mode exception?
|
||||
|
||||
**10b)** **Testing with Real Providers**: To test against real IndieAuth providers, I need:
|
||||
- A real profile URL with IndieAuth links
|
||||
- Valid tokens from that provider
|
||||
|
||||
Should I:
|
||||
- Create test profile for integration tests?
|
||||
- Document how developers can test?
|
||||
- Skip real provider tests in CI (only run locally)?
|
||||
|
||||
---
|
||||
|
||||
## Implementation Readiness Assessment
|
||||
|
||||
### What's Clear and Ready to Implement
|
||||
|
||||
✅ **HTTP Link Header Parsing**: Clear algorithm, standard format
|
||||
✅ **HTML Link Element Extraction**: Clear approach with BeautifulSoup4
|
||||
✅ **URL Resolution**: Standard `urljoin()` from urllib.parse
|
||||
✅ **Basic Caching**: In-memory dict with TTL expiry
|
||||
✅ **Token Verification HTTP Request**: Standard GET with Bearer token
|
||||
✅ **Response Validation**: Check for required fields (me, client_id, scope)
|
||||
|
||||
### What Needs Architect Clarification
|
||||
|
||||
⚠️ **Critical (blocks implementation)**:
|
||||
- Q1: Which endpoint to verify tokens with (the "chicken-and-egg" problem)
|
||||
- Q2a: Cache structure for single-user vs future multi-user
|
||||
- Q3a: Add BeautifulSoup4 dependency?
|
||||
|
||||
⚠️ **Important (affects quality)**:
|
||||
- Q5a: URL validation requirements
|
||||
- Q6a: Error handling strategy (fail open vs closed)
|
||||
- Q6b: Retry logic for network failures
|
||||
- Q9a: Remove TOKEN_ENDPOINT config or deprecate?
|
||||
|
||||
⚠️ **Nice to have (can implement sensibly)**:
|
||||
- Q2c: Cache invalidation triggers
|
||||
- Q7a: Test strategy (mock vs real)
|
||||
- Q8a: First request latency acceptable?
|
||||
|
||||
---
|
||||
|
||||
## Proposed Implementation Plan
|
||||
|
||||
Once questions are answered, here's my implementation approach:
|
||||
|
||||
### Phase 1: Core Discovery (Days 1-2)
|
||||
1. Create `endpoint_discovery.py` module
|
||||
- `EndpointDiscovery` class
|
||||
- HTTP Link header parsing
|
||||
- HTML link element extraction
|
||||
- URL resolution and validation
|
||||
- Error handling
|
||||
|
||||
2. Unit tests for discovery
|
||||
- Test Link header parsing
|
||||
- Test HTML parsing
|
||||
- Test URL resolution
|
||||
- Test error cases
|
||||
|
||||
### Phase 2: Token Verification Update (Day 3)
|
||||
1. Update `auth_external.py`
|
||||
- Integrate endpoint discovery
|
||||
- Add caching layer
|
||||
- Update `verify_external_token()`
|
||||
- Remove hardcoded TOKEN_ENDPOINT usage
|
||||
|
||||
2. Unit tests for updated verification
|
||||
- Test with discovered endpoints
|
||||
- Test caching behavior
|
||||
- Test error handling
|
||||
|
||||
### Phase 3: Integration and Testing (Day 4)
|
||||
1. Integration tests
|
||||
- Full Micropub request flow
|
||||
- Cache behavior across requests
|
||||
- Error scenarios
|
||||
|
||||
2. Update existing tests
|
||||
- Fix any broken tests
|
||||
- Update mocks to use discovery
|
||||
|
||||
### Phase 4: Configuration and Documentation (Day 5)
|
||||
1. Update configuration
|
||||
- Remove TOKEN_ENDPOINT from config.py
|
||||
- Add deprecation warning if still set
|
||||
- Update .env.example
|
||||
|
||||
2. Update documentation
|
||||
- CHANGELOG entry for rc.5
|
||||
- Migration guide if needed
|
||||
- API documentation
|
||||
|
||||
### Phase 5: Manual Testing and Refinement (Day 6)
|
||||
1. Test with real IndieAuth provider
|
||||
2. Performance testing (cache effectiveness)
|
||||
3. Error handling verification
|
||||
4. Final refinements
|
||||
|
||||
**Estimated Total Time**: 5-7 days
|
||||
|
||||
---
|
||||
|
||||
## Dependencies to Add
|
||||
|
||||
Based on migration guide, I'll need to add:
|
||||
|
||||
```toml
|
||||
# pyproject.toml or requirements.txt
|
||||
beautifulsoup4>=4.12.0 # HTML parsing for link extraction
|
||||
```
|
||||
|
||||
`httpx` is already a dependency (used in current auth_external.py).
|
||||
|
||||
---
|
||||
|
||||
## Risks and Concerns
|
||||
|
||||
### Risk 1: Breaking Change Timing
|
||||
- **Issue**: RC.4 just shipped with TOKEN_ENDPOINT config
|
||||
- **Impact**: Users testing RC.4 will need to reconfigure for RC.5
|
||||
- **Mitigation**: Clear migration notes in CHANGELOG, consider grace period
|
||||
|
||||
### Risk 2: Performance Degradation
|
||||
- **Issue**: First request will be slower (800ms vs <100ms cached)
|
||||
- **Impact**: User experience on first post after restart/cache expiry
|
||||
- **Mitigation**: Document expected behavior, consider pre-warming cache
|
||||
|
||||
### Risk 3: External Dependency
|
||||
- **Issue**: StarPunk now depends on external profile URL availability
|
||||
- **Impact**: If profile URL is down, Micropub stops working
|
||||
- **Mitigation**: Cache endpoints for longer TTL, fail gracefully with clear errors
|
||||
|
||||
### Risk 4: Testing Complexity
|
||||
- **Issue**: More moving parts to test (HTTP, HTML parsing, caching)
|
||||
- **Impact**: More test code, more mocking, more edge cases
|
||||
- **Mitigation**: Good test fixtures, clear test organization
|
||||
|
||||
---
|
||||
|
||||
## Recommended Next Steps
|
||||
|
||||
1. **Architect reviews this report** and answers questions
|
||||
2. **I create test fixtures** based on ADR examples
|
||||
3. **I implement Phase 1** (core discovery) with tests
|
||||
4. **Checkpoint review** - verify discovery working correctly
|
||||
5. **I implement Phase 2** (integration with token verification)
|
||||
6. **Checkpoint review** - verify end-to-end flow
|
||||
7. **I implement Phase 3-5** (tests, config, docs)
|
||||
8. **Final review** before merge
|
||||
|
||||
---
|
||||
|
||||
## Questions Summary (Quick Reference)
|
||||
|
||||
**Critical** (must answer before coding):
|
||||
1. Q1: Which endpoint to verify tokens with? Proposed: Use ADMIN_ME profile for single-user StarPunk
|
||||
2. Q2a: Cache structure for single-user vs multi-user?
|
||||
3. Q3a: Add BeautifulSoup4 dependency?
|
||||
|
||||
**Important** (affects implementation quality):
|
||||
4. Q5a: URL validation requirements?
|
||||
5. Q6a: Error handling strategy (fail open/closed)?
|
||||
6. Q6b: Retry logic for network failures?
|
||||
7. Q9a: Remove or deprecate TOKEN_ENDPOINT config?
|
||||
|
||||
**Can implement sensibly** (but prefer guidance):
|
||||
8. Q2c: Cache invalidation triggers?
|
||||
9. Q7a: Test strategy (mock vs real)?
|
||||
10. Q8a: First request latency acceptable?
|
||||
|
||||
---
|
||||
|
||||
## Conclusion
|
||||
|
||||
The architect's corrected design is sound and properly implements IndieAuth endpoint discovery per the W3C specification. The primary blocker is clarifying the "which endpoint?" question for token verification in a single-user CMS context.
|
||||
|
||||
My proposed solution (always use ADMIN_ME profile for endpoint discovery) seems correct for StarPunk's single-user model, but I need architect confirmation before proceeding.
|
||||
|
||||
Once questions are answered, I'm ready to implement with high confidence. The code will be clean, tested, and follow the specifications exactly.
|
||||
|
||||
**Status**: ⏸️ **Waiting for Architect Review**
|
||||
|
||||
---
|
||||
|
||||
**Document Version**: 1.0
|
||||
**Created**: 2025-11-24
|
||||
**Author**: StarPunk Fullstack Developer
|
||||
**Next Review**: After architect responds to questions
|
||||
397
docs/security/indieauth-endpoint-discovery-security.md
Normal file
397
docs/security/indieauth-endpoint-discovery-security.md
Normal file
@@ -0,0 +1,397 @@
|
||||
# IndieAuth Endpoint Discovery Security Analysis
|
||||
|
||||
## Executive Summary
|
||||
|
||||
This document analyzes the security implications of implementing IndieAuth endpoint discovery correctly, contrasting it with the fundamentally flawed approach of hardcoding endpoints.
|
||||
|
||||
## The Critical Error: Hardcoded Endpoints
|
||||
|
||||
### What Was Wrong
|
||||
|
||||
```ini
|
||||
# FATALLY FLAWED - Breaks IndieAuth completely
|
||||
TOKEN_ENDPOINT=https://tokens.indieauth.com/token
|
||||
```
|
||||
|
||||
### Why It's a Security Disaster
|
||||
|
||||
1. **Single Point of Failure**: If the hardcoded endpoint is compromised, ALL users are affected
|
||||
2. **No User Control**: Users cannot change providers if security issues arise
|
||||
3. **Trust Concentration**: Forces all users to trust a single provider
|
||||
4. **Not IndieAuth**: This isn't IndieAuth at all - it's just OAuth with extra steps
|
||||
5. **Violates User Sovereignty**: Users don't control their own authentication
|
||||
|
||||
## The Correct Approach: Dynamic Discovery
|
||||
|
||||
### Security Model
|
||||
|
||||
```
|
||||
User Identity URL → Endpoint Discovery → Provider Verification
|
||||
(User Controls) (Dynamic) (User's Choice)
|
||||
```
|
||||
|
||||
### Security Benefits
|
||||
|
||||
1. **Distributed Trust**: No single provider compromise affects all users
|
||||
2. **User Control**: Users can switch providers instantly if needed
|
||||
3. **Provider Independence**: Each user's security is independent
|
||||
4. **Immediate Revocation**: Users can revoke by changing profile links
|
||||
5. **True Decentralization**: No central authority
|
||||
|
||||
## Threat Analysis
|
||||
|
||||
### Threat 1: Profile URL Hijacking
|
||||
|
||||
**Attack Vector**: Attacker gains control of user's profile URL
|
||||
|
||||
**Impact**: Can redirect authentication to attacker's endpoints
|
||||
|
||||
**Mitigations**:
|
||||
- Profile URL must use HTTPS
|
||||
- Verify SSL certificates
|
||||
- Monitor for unexpected endpoint changes
|
||||
- Cache endpoints with reasonable TTL
|
||||
|
||||
### Threat 2: Endpoint Discovery Manipulation
|
||||
|
||||
**Attack Vector**: MITM attack during endpoint discovery
|
||||
|
||||
**Impact**: Could redirect to malicious endpoints
|
||||
|
||||
**Mitigations**:
|
||||
```python
|
||||
def discover_endpoints(profile_url: str) -> dict:
|
||||
# CRITICAL: Enforce HTTPS
|
||||
if not profile_url.startswith('https://'):
|
||||
raise SecurityError("Profile URL must use HTTPS")
|
||||
|
||||
# Verify SSL certificates
|
||||
response = requests.get(
|
||||
profile_url,
|
||||
verify=True, # Enforce certificate validation
|
||||
timeout=5
|
||||
)
|
||||
|
||||
# Validate discovered endpoints
|
||||
endpoints = extract_endpoints(response)
|
||||
for endpoint_url in endpoints.values():
|
||||
if not endpoint_url.startswith('https://'):
|
||||
raise SecurityError(f"Endpoint must use HTTPS: {endpoint_url}")
|
||||
|
||||
return endpoints
|
||||
```
|
||||
|
||||
### Threat 3: Cache Poisoning
|
||||
|
||||
**Attack Vector**: Attacker poisons endpoint cache with malicious URLs
|
||||
|
||||
**Impact**: Subsequent requests use attacker's endpoints
|
||||
|
||||
**Mitigations**:
|
||||
```python
|
||||
class SecureEndpointCache:
|
||||
def store_endpoints(self, profile_url: str, endpoints: dict):
|
||||
# Validate before caching
|
||||
self._validate_profile_url(profile_url)
|
||||
self._validate_endpoints(endpoints)
|
||||
|
||||
# Store with integrity check
|
||||
cache_entry = {
|
||||
'endpoints': endpoints,
|
||||
'stored_at': time.time(),
|
||||
'checksum': self._calculate_checksum(endpoints)
|
||||
}
|
||||
self.cache[profile_url] = cache_entry
|
||||
|
||||
def get_endpoints(self, profile_url: str) -> dict:
|
||||
entry = self.cache.get(profile_url)
|
||||
if entry:
|
||||
# Verify integrity
|
||||
if self._calculate_checksum(entry['endpoints']) != entry['checksum']:
|
||||
# Cache corruption detected
|
||||
del self.cache[profile_url]
|
||||
raise SecurityError("Cache integrity check failed")
|
||||
return entry['endpoints']
|
||||
```
|
||||
|
||||
### Threat 4: Redirect Attacks
|
||||
|
||||
**Attack Vector**: Malicious redirects during discovery
|
||||
|
||||
**Impact**: Could redirect to attacker-controlled endpoints
|
||||
|
||||
**Mitigations**:
|
||||
```python
|
||||
def fetch_with_redirect_limit(url: str, max_redirects: int = 5):
|
||||
redirect_count = 0
|
||||
visited = set()
|
||||
|
||||
while redirect_count < max_redirects:
|
||||
if url in visited:
|
||||
raise SecurityError("Redirect loop detected")
|
||||
visited.add(url)
|
||||
|
||||
response = requests.get(url, allow_redirects=False)
|
||||
|
||||
if response.status_code in (301, 302, 303, 307, 308):
|
||||
redirect_url = response.headers.get('Location')
|
||||
|
||||
# Validate redirect target
|
||||
if not redirect_url.startswith('https://'):
|
||||
raise SecurityError("Redirect to non-HTTPS URL blocked")
|
||||
|
||||
url = redirect_url
|
||||
redirect_count += 1
|
||||
else:
|
||||
return response
|
||||
|
||||
raise SecurityError("Too many redirects")
|
||||
```
|
||||
|
||||
### Threat 5: Token Replay Attacks
|
||||
|
||||
**Attack Vector**: Intercepted token reused
|
||||
|
||||
**Impact**: Unauthorized access
|
||||
|
||||
**Mitigations**:
|
||||
- Always use HTTPS for token transmission
|
||||
- Implement token expiration
|
||||
- Cache token verification results briefly
|
||||
- Use nonce/timestamp validation
|
||||
|
||||
## Security Requirements
|
||||
|
||||
### 1. HTTPS Enforcement
|
||||
|
||||
```python
|
||||
class HTTPSEnforcer:
|
||||
def validate_url(self, url: str, context: str):
|
||||
"""Enforce HTTPS for all security-critical URLs"""
|
||||
|
||||
parsed = urlparse(url)
|
||||
|
||||
# Development exception (with warning)
|
||||
if self.development_mode and parsed.hostname in ['localhost', '127.0.0.1']:
|
||||
logger.warning(f"Allowing HTTP in development for {context}: {url}")
|
||||
return
|
||||
|
||||
# Production: HTTPS required
|
||||
if parsed.scheme != 'https':
|
||||
raise SecurityError(f"HTTPS required for {context}: {url}")
|
||||
```
|
||||
|
||||
### 2. Certificate Validation
|
||||
|
||||
```python
|
||||
def create_secure_http_client():
|
||||
"""Create HTTP client with proper security settings"""
|
||||
|
||||
return httpx.Client(
|
||||
verify=True, # Always verify SSL certificates
|
||||
follow_redirects=False, # Handle redirects manually
|
||||
timeout=httpx.Timeout(
|
||||
connect=5.0,
|
||||
read=10.0,
|
||||
write=10.0,
|
||||
pool=10.0
|
||||
),
|
||||
limits=httpx.Limits(
|
||||
max_connections=100,
|
||||
max_keepalive_connections=20
|
||||
),
|
||||
headers={
|
||||
'User-Agent': 'StarPunk/1.0 (+https://starpunk.example.com/)'
|
||||
}
|
||||
)
|
||||
```
|
||||
|
||||
### 3. Input Validation
|
||||
|
||||
```python
|
||||
def validate_endpoint_response(response: dict, expected_me: str):
|
||||
"""Validate token verification response"""
|
||||
|
||||
# Required fields
|
||||
if 'me' not in response:
|
||||
raise ValidationError("Missing 'me' field in response")
|
||||
|
||||
# URL normalization and comparison
|
||||
normalized_me = normalize_url(response['me'])
|
||||
normalized_expected = normalize_url(expected_me)
|
||||
|
||||
if normalized_me != normalized_expected:
|
||||
raise ValidationError(
|
||||
f"Token 'me' mismatch: expected {normalized_expected}, "
|
||||
f"got {normalized_me}"
|
||||
)
|
||||
|
||||
# Scope validation
|
||||
scopes = response.get('scope', '').split()
|
||||
if 'create' not in scopes:
|
||||
raise ValidationError("Token missing required 'create' scope")
|
||||
|
||||
return True
|
||||
```
|
||||
|
||||
### 4. Rate Limiting
|
||||
|
||||
```python
|
||||
class DiscoveryRateLimiter:
|
||||
"""Prevent discovery abuse"""
|
||||
|
||||
def __init__(self, max_per_minute: int = 60):
|
||||
self.requests = defaultdict(list)
|
||||
self.max_per_minute = max_per_minute
|
||||
|
||||
def check_rate_limit(self, profile_url: str):
|
||||
now = time.time()
|
||||
minute_ago = now - 60
|
||||
|
||||
# Clean old entries
|
||||
self.requests[profile_url] = [
|
||||
t for t in self.requests[profile_url]
|
||||
if t > minute_ago
|
||||
]
|
||||
|
||||
# Check limit
|
||||
if len(self.requests[profile_url]) >= self.max_per_minute:
|
||||
raise RateLimitError(f"Too many discovery requests for {profile_url}")
|
||||
|
||||
# Record request
|
||||
self.requests[profile_url].append(now)
|
||||
```
|
||||
|
||||
## Implementation Checklist
|
||||
|
||||
### Discovery Security
|
||||
|
||||
- [ ] Enforce HTTPS for profile URLs
|
||||
- [ ] Validate SSL certificates
|
||||
- [ ] Limit redirect chains to 5
|
||||
- [ ] Detect redirect loops
|
||||
- [ ] Validate discovered endpoint URLs
|
||||
- [ ] Implement discovery rate limiting
|
||||
- [ ] Log all discovery attempts
|
||||
- [ ] Handle timeouts gracefully
|
||||
|
||||
### Token Verification Security
|
||||
|
||||
- [ ] Use HTTPS for all token endpoints
|
||||
- [ ] Validate token endpoint responses
|
||||
- [ ] Check 'me' field matches expected
|
||||
- [ ] Verify required scopes present
|
||||
- [ ] Hash tokens before caching
|
||||
- [ ] Implement cache expiration
|
||||
- [ ] Use constant-time comparisons
|
||||
- [ ] Log verification failures
|
||||
|
||||
### Cache Security
|
||||
|
||||
- [ ] Validate data before caching
|
||||
- [ ] Implement cache size limits
|
||||
- [ ] Use TTL for all cache entries
|
||||
- [ ] Clear cache on configuration changes
|
||||
- [ ] Protect against cache poisoning
|
||||
- [ ] Monitor cache hit/miss rates
|
||||
- [ ] Implement cache integrity checks
|
||||
|
||||
### Error Handling
|
||||
|
||||
- [ ] Never expose internal errors
|
||||
- [ ] Log security events
|
||||
- [ ] Rate limit error responses
|
||||
- [ ] Implement proper timeouts
|
||||
- [ ] Handle network failures gracefully
|
||||
- [ ] Provide clear user messages
|
||||
|
||||
## Security Testing
|
||||
|
||||
### Test Scenarios
|
||||
|
||||
1. **HTTPS Downgrade Attack**
|
||||
- Try to use HTTP endpoints
|
||||
- Verify rejection
|
||||
|
||||
2. **Invalid Certificates**
|
||||
- Test with self-signed certs
|
||||
- Test with expired certs
|
||||
- Verify rejection
|
||||
|
||||
3. **Redirect Attacks**
|
||||
- Test redirect loops
|
||||
- Test excessive redirects
|
||||
- Test HTTP redirects
|
||||
- Verify proper handling
|
||||
|
||||
4. **Cache Poisoning**
|
||||
- Attempt to inject invalid data
|
||||
- Verify cache validation
|
||||
|
||||
5. **Token Manipulation**
|
||||
- Modify token before verification
|
||||
- Test expired tokens
|
||||
- Test tokens with wrong 'me'
|
||||
- Verify proper rejection
|
||||
|
||||
## Monitoring and Alerting
|
||||
|
||||
### Security Metrics
|
||||
|
||||
```python
|
||||
# Track these metrics
|
||||
security_metrics = {
|
||||
'discovery_failures': Counter(),
|
||||
'https_violations': Counter(),
|
||||
'certificate_errors': Counter(),
|
||||
'redirect_limit_exceeded': Counter(),
|
||||
'cache_poisoning_attempts': Counter(),
|
||||
'token_verification_failures': Counter(),
|
||||
'rate_limit_violations': Counter()
|
||||
}
|
||||
```
|
||||
|
||||
### Alert Conditions
|
||||
|
||||
- Multiple discovery failures for same profile
|
||||
- Sudden increase in HTTPS violations
|
||||
- Certificate validation failures
|
||||
- Cache poisoning attempts detected
|
||||
- Unusual token verification patterns
|
||||
|
||||
## Incident Response
|
||||
|
||||
### If Endpoint Compromise Suspected
|
||||
|
||||
1. Clear endpoint cache immediately
|
||||
2. Force re-discovery of all endpoints
|
||||
3. Alert affected users
|
||||
4. Review logs for suspicious patterns
|
||||
5. Document incident
|
||||
|
||||
### If Cache Poisoning Detected
|
||||
|
||||
1. Clear entire cache
|
||||
2. Review cache validation logic
|
||||
3. Identify attack vector
|
||||
4. Implement additional validation
|
||||
5. Monitor for recurrence
|
||||
|
||||
## Conclusion
|
||||
|
||||
Dynamic endpoint discovery is not just correct according to the IndieAuth specification - it's also more secure than hardcoded endpoints. By allowing users to control their authentication infrastructure, we:
|
||||
|
||||
1. Eliminate single points of failure
|
||||
2. Enable immediate provider switching
|
||||
3. Distribute security responsibility
|
||||
4. Maintain true decentralization
|
||||
5. Respect user sovereignty
|
||||
|
||||
The complexity of proper implementation is justified by the security and flexibility benefits. This is what IndieAuth is designed to provide, and we must implement it correctly.
|
||||
|
||||
---
|
||||
|
||||
**Document Version**: 1.0
|
||||
**Created**: 2024-11-24
|
||||
**Classification**: Security Architecture
|
||||
**Review Schedule**: Quarterly
|
||||
Reference in New Issue
Block a user