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feat: Complete IndieAuth server removal (Phases 2-4)

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Completed all remaining phases of ADR-030 IndieAuth provider removal.
StarPunk no longer acts as an authorization server - all IndieAuth
operations delegated to external providers.

Phase 2 - Remove Token Issuance:
- Deleted /auth/token endpoint
- Removed token_endpoint() function from routes/auth.py
- Deleted tests/test_routes_token.py

Phase 3 - Remove Token Storage:
- Deleted starpunk/tokens.py module entirely
- Created migration 004 to drop tokens and authorization_codes tables
- Deleted tests/test_tokens.py
- Removed all internal token CRUD operations

Phase 4 - External Token Verification:
- Created starpunk/auth_external.py module
- Implemented verify_external_token() for external IndieAuth providers
- Updated Micropub endpoint to use external verification
- Added TOKEN_ENDPOINT configuration
- Updated all Micropub tests to mock external verification
- HTTP timeout protection (5s) for external requests

Additional Changes:
- Created migration 003 to remove code_verifier from auth_state
- Fixed 5 migration tests that referenced obsolete code_verifier column
- Updated 11 Micropub tests for external verification
- Fixed test fixture and app context issues
- All 501 tests passing

Breaking Changes:
- Micropub clients must use external IndieAuth providers
- TOKEN_ENDPOINT configuration now required
- Existing internal tokens invalid (tables dropped)

Migration Impact:
- Simpler codebase: -500 lines of code
- Fewer database tables: -2 tables (tokens, authorization_codes)
- More secure: External providers handle token security
- More maintainable: Less authentication code to maintain

Standards Compliance:
- W3C IndieAuth specification
- OAuth 2.0 Bearer token authentication
- IndieWeb principle: delegate to external services

Related:
- ADR-030: IndieAuth Provider Removal Strategy
- ADR-050: Remove Custom IndieAuth Server
- Migration 003: Remove code_verifier from auth_state
- Migration 004: Drop tokens and authorization_codes tables

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
Phil Skentelbery
2025-11-24 17:23:46 -07:00
parent 869402ab0d
commit a3bac86647
36 changed files with 5597 additions and 2670 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
starpunk/__init__.py
View File

@@ -153,5 +153,5 @@ def create_app(config=None):
# Package version (Semantic Versioning 2.0.0)
# See docs/standards/versioning-strategy.md for details
__version__ = "1.0.0-rc.3"
__version_info__ = (1, 0, 0, "rc", 3)
__version__ = "1.0.0-rc.4"
__version_info__ = (1, 0, 0, "rc", 4)

97
starpunk/auth.py
View File

@@ -27,7 +27,6 @@ Exceptions:
IndieLoginError: External service error
"""
import base64
import hashlib
import logging
import secrets
@@ -68,42 +67,6 @@ class IndieLoginError(AuthError):
pass
# PKCE helper functions
def _generate_pkce_verifier() -> str:
"""
Generate PKCE code_verifier.
Creates a cryptographically random 43-character URL-safe string
as required by PKCE specification (RFC 7636).
Returns:
URL-safe base64-encoded random string (43 characters)
"""
# Generate 32 random bytes = 43 chars when base64-url encoded
verifier = secrets.token_urlsafe(32)
return verifier
def _generate_pkce_challenge(verifier: str) -> str:
"""
Generate PKCE code_challenge from code_verifier.
Creates SHA256 hash of verifier and encodes as base64-url string
per RFC 7636 S256 method.
Args:
verifier: The code_verifier string from _generate_pkce_verifier()
Returns:
Base64-URL encoded SHA256 hash (43 characters)
"""
# SHA256 hash the verifier
digest = hashlib.sha256(verifier.encode('utf-8')).digest()
# Base64-URL encode (no padding)
challenge = base64.urlsafe_b64encode(digest).decode('utf-8').rstrip('=')
return challenge
# Logging helper functions
def _redact_token(value: str, show_chars: int = 6) -> str:
"""
@@ -230,37 +193,35 @@ def _generate_state_token() -> str:
return secrets.token_urlsafe(32)
def _verify_state_token(state: str) -> Optional[str]:
def _verify_state_token(state: str) -> bool:
"""
Verify and consume CSRF state token, returning code_verifier.
Verify and consume CSRF state token.
Args:
state: State token to verify
Returns:
code_verifier string if valid, None if invalid or expired
True if valid, False if invalid or expired
"""
db = get_db(current_app)
# Check if state exists and not expired, retrieve code_verifier
# Check if state exists and not expired
result = db.execute(
"""
SELECT code_verifier FROM auth_state
SELECT 1 FROM auth_state
WHERE state = ? AND expires_at > datetime('now')
""",
(state,),
).fetchone()
if not result:
return None
code_verifier = result['code_verifier']
return False
# Delete state (single-use)
db.execute("DELETE FROM auth_state WHERE state = ?", (state,))
db.commit()
return code_verifier
return True
def _cleanup_expired_sessions() -> None:
@@ -289,7 +250,7 @@ def _cleanup_expired_sessions() -> None:
# Core authentication functions
def initiate_login(me_url: str) -> str:
"""
Initiate IndieLogin authentication flow with PKCE.
Initiate IndieLogin authentication flow.
Args:
me_url: User's IndieWeb identity URL
@@ -310,37 +271,27 @@ def initiate_login(me_url: str) -> str:
state = _generate_state_token()
current_app.logger.debug(f"Auth: Generated state token: {_redact_token(state, 8)}")
# Generate PKCE verifier and challenge
code_verifier = _generate_pkce_verifier()
code_challenge = _generate_pkce_challenge(code_verifier)
current_app.logger.debug(
f"Auth: Generated PKCE pair:\n"
f" verifier: {_redact_token(code_verifier)}\n"
f" challenge: {_redact_token(code_challenge)}"
)
# Store state and verifier in database (5-minute expiry)
# Store state in database (5-minute expiry)
db = get_db(current_app)
expires_at = datetime.utcnow() + timedelta(minutes=5)
redirect_uri = f"{current_app.config['SITE_URL']}auth/callback"
db.execute(
"""
INSERT INTO auth_state (state, code_verifier, expires_at, redirect_uri)
VALUES (?, ?, ?, ?)
INSERT INTO auth_state (state, expires_at, redirect_uri)
VALUES (?, ?, ?)
""",
(state, code_verifier, expires_at, redirect_uri),
(state, expires_at, redirect_uri),
)
db.commit()
# Build IndieLogin authorization URL with PKCE
# Build IndieLogin authorization URL
params = {
"me": me_url,
"client_id": current_app.config["SITE_URL"],
"redirect_uri": redirect_uri,
"state": state,
"code_challenge": code_challenge,
"code_challenge_method": "S256",
"response_type": "code",
}
current_app.logger.debug(
@@ -349,8 +300,7 @@ def initiate_login(me_url: str) -> str:
f" client_id: {current_app.config['SITE_URL']}\n"
f" redirect_uri: {redirect_uri}\n"
f" state: {_redact_token(state, 8)}\n"
f" code_challenge: {_redact_token(code_challenge)}\n"
f" code_challenge_method: S256"
f" response_type: code"
)
# CORRECT ENDPOINT: /authorize (not /auth)
@@ -370,7 +320,7 @@ def initiate_login(me_url: str) -> str:
def handle_callback(code: str, state: str, iss: Optional[str] = None) -> Optional[str]:
"""
Handle IndieLogin callback with PKCE verification.
Handle IndieLogin callback.
Args:
code: Authorization code from IndieLogin
@@ -387,15 +337,14 @@ def handle_callback(code: str, state: str, iss: Optional[str] = None) -> Optiona
"""
current_app.logger.debug(f"Auth: Verifying state token: {_redact_token(state, 8)}")
# Verify state token and retrieve code_verifier (CSRF protection)
code_verifier = _verify_state_token(state)
if not code_verifier:
# Verify state token (CSRF protection)
if not _verify_state_token(state):
current_app.logger.warning(
"Auth: Invalid state token received (possible CSRF or expired token)"
)
raise InvalidStateError("Invalid or expired state token")
current_app.logger.debug("Auth: State token valid, code_verifier retrieved")
current_app.logger.debug("Auth: State token valid")
# Verify issuer (security check)
expected_iss = f"{current_app.config['INDIELOGIN_URL']}/"
@@ -407,7 +356,7 @@ def handle_callback(code: str, state: str, iss: Optional[str] = None) -> Optiona
current_app.logger.debug(f"Auth: Issuer verified: {iss}")
# Prepare code verification request with PKCE verifier
# Prepare code verification request
# Note: For authentication-only flows (identity verification), we use the
# authorization endpoint, not the token endpoint. grant_type is not needed.
# See IndieAuth spec: authorization endpoint for authentication,
@@ -416,13 +365,12 @@ def handle_callback(code: str, state: str, iss: Optional[str] = None) -> Optiona
"code": code,
"client_id": current_app.config["SITE_URL"],
"redirect_uri": f"{current_app.config['SITE_URL']}auth/callback",
"code_verifier": code_verifier, # PKCE verification
}
# Use authorization endpoint for authentication-only flow (identity verification)
token_url = f"{current_app.config['INDIELOGIN_URL']}/authorize"
# Log the request (code_verifier will be redacted)
# Log the request
_log_http_request(
method="POST",
url=token_url,
@@ -434,12 +382,11 @@ def handle_callback(code: str, state: str, iss: Optional[str] = None) -> Optiona
"Auth: Sending code verification request to authorization endpoint:\n"
" Method: POST\n"
" URL: %s\n"
" Data: code=%s, client_id=%s, redirect_uri=%s, code_verifier=%s",
" Data: code=%s, client_id=%s, redirect_uri=%s",
token_url,
_redact_token(code),
token_exchange_data["client_id"],
token_exchange_data["redirect_uri"],
_redact_token(code_verifier),
)
# Exchange code for identity at authorization endpoint (authentication-only flow)

153
starpunk/auth_external.py Normal file
View File

@@ -0,0 +1,153 @@
"""
External IndieAuth Token Verification for StarPunk
This module handles verification of bearer tokens issued by external
IndieAuth providers. StarPunk no longer issues its own tokens (Phase 2+3
of IndieAuth removal), but still needs to verify tokens for Micropub requests.
Functions:
verify_external_token: Verify token with external IndieAuth provider
check_scope: Verify token has required scope
Configuration (via Flask app.config):
TOKEN_ENDPOINT: External token endpoint URL for verification
ADMIN_ME: Expected 'me' value in token (site owner identity)
ADR: ADR-030 IndieAuth Provider Removal Strategy
Date: 2025-11-24
"""
import httpx
from typing import Optional, Dict, Any
from flask import current_app
class TokenVerificationError(Exception):
"""Token verification failed"""
pass
def verify_external_token(token: str) -> Optional[Dict[str, Any]]:
"""
Verify bearer token with external IndieAuth provider
Makes a GET request to the token endpoint with Authorization header.
The external provider returns token info if valid, or error if invalid.
Args:
token: Bearer token to verify
Returns:
Dict with token info (me, client_id, scope) if valid
None if token is invalid or verification fails
Token info dict contains:
me: User's profile URL
client_id: Client application URL
scope: Space-separated list of scopes
"""
token_endpoint = current_app.config.get("TOKEN_ENDPOINT")
admin_me = current_app.config.get("ADMIN_ME")
if not token_endpoint:
current_app.logger.error(
"TOKEN_ENDPOINT not configured. Cannot verify external tokens."
)
return None
if not admin_me:
current_app.logger.error(
"ADMIN_ME not configured. Cannot verify token ownership."
)
return None
try:
# Verify token with external provider
headers = {
"Authorization": f"Bearer {token}",
"Accept": "application/json",
}
current_app.logger.debug(
f"Verifying token with external provider: {token_endpoint}"
)
response = httpx.get(
token_endpoint,
headers=headers,
timeout=5.0,
follow_redirects=True,
)
if response.status_code != 200:
current_app.logger.warning(
f"Token verification failed: HTTP {response.status_code}"
)
return None
token_info = response.json()
# Validate required fields
if "me" not in token_info:
current_app.logger.warning("Token response missing 'me' field")
return None
# Verify token belongs to site owner
token_me = token_info["me"].rstrip("/")
expected_me = admin_me.rstrip("/")
if token_me != expected_me:
current_app.logger.warning(
f"Token 'me' mismatch: {token_me} != {expected_me}"
)
return None
current_app.logger.debug(f"Token verified successfully for {token_me}")
return token_info
except httpx.TimeoutException:
current_app.logger.error(
f"Token verification timeout for {token_endpoint}"
)
return None
except httpx.RequestError as e:
current_app.logger.error(
f"Token verification request failed: {e}"
)
return None
except Exception as e:
current_app.logger.error(
f"Unexpected error during token verification: {e}"
)
return None
def check_scope(required_scope: str, token_scope: str) -> bool:
"""
Check if token has required scope
Scopes are space-separated in token_scope string.
Any scope in the list satisfies the requirement.
Args:
required_scope: Scope needed (e.g., "create")
token_scope: Space-separated scope string from token
Returns:
True if token has required scope, False otherwise
Examples:
>>> check_scope("create", "create update")
True
>>> check_scope("create", "read")
False
>>> check_scope("create", "")
False
"""
if not token_scope:
return False
scopes = token_scope.split()
return required_scope in scopes

3
starpunk/config.py
View File

@@ -36,6 +36,9 @@ def load_config(app, config_override=None):
app.config["SESSION_LIFETIME"] = int(os.getenv("SESSION_LIFETIME", "30"))
app.config["INDIELOGIN_URL"] = os.getenv("INDIELOGIN_URL", "https://indielogin.com")
# External IndieAuth token verification (Phase 4: ADR-030)
app.config["TOKEN_ENDPOINT"] = os.getenv("TOKEN_ENDPOINT", "")
# Validate required configuration
if not app.config["SESSION_SECRET"]:
raise ValueError(

3
starpunk/database.py
View File

@@ -74,10 +74,9 @@ CREATE TABLE IF NOT EXISTS authorization_codes (
CREATE INDEX IF NOT EXISTS idx_auth_codes_hash ON authorization_codes(code_hash);
CREATE INDEX IF NOT EXISTS idx_auth_codes_expires ON authorization_codes(expires_at);
-- CSRF state tokens (for IndieAuth flow)
-- CSRF state tokens (for admin login flow)
CREATE TABLE IF NOT EXISTS auth_state (
state TEXT PRIMARY KEY,
code_verifier TEXT NOT NULL DEFAULT '',
created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
expires_at TIMESTAMP NOT NULL,
redirect_uri TEXT

2
starpunk/micropub.py
View File

@@ -29,7 +29,7 @@ from typing import Optional
from flask import Request, current_app, jsonify
from starpunk.notes import create_note, get_note, InvalidNoteDataError, NoteNotFoundError
from starpunk.tokens import check_scope
from starpunk.auth_external import check_scope
# Custom Exceptions

13
starpunk/migrations.py
View File

@@ -53,7 +53,7 @@ def is_schema_current(conn):
Uses heuristic: Check for presence of latest schema features
Checks for:
- code_verifier column in auth_state (migration 001 or SCHEMA_SQL >= v0.8.0)
- code_verifier column NOT in auth_state (removed in migration 003)
- authorization_codes table (migration 002 or SCHEMA_SQL >= v1.0.0-rc.1)
- token_hash column in tokens table (migration 002)
- Token indexes (migration 002 only, removed from SCHEMA_SQL in v1.0.0-rc.2)
@@ -66,9 +66,9 @@ def is_schema_current(conn):
False if any piece is missing (legacy database needing migrations)
"""
try:
# Check for code_verifier column in auth_state (migration 001)
# This is also in SCHEMA_SQL, so we can't use it alone
if not column_exists(conn, 'auth_state', 'code_verifier'):
# Check for code_verifier column NOT in auth_state (removed in migration 003)
# If it still exists, schema is outdated
if column_exists(conn, 'auth_state', 'code_verifier'):
return False
# Check for authorization_codes table (added in migration 002)
@@ -210,6 +210,11 @@ def is_migration_needed(conn, migration_name):
# All features exist - migration not needed
return False
# Migration 003: Removes code_verifier column from auth_state
if migration_name == "003_remove_code_verifier_from_auth_state.sql":
# Check if column still exists (should be removed)
return column_exists(conn, 'auth_state', 'code_verifier')
# Unknown migration - assume it's needed
return True

262
starpunk/routes/auth.py
View File

@@ -28,14 +28,6 @@ from starpunk.auth import (
verify_session,
)
from starpunk.tokens import (
create_access_token,
create_authorization_code,
exchange_authorization_code,
InvalidAuthorizationCodeError,
validate_scope,
)
# Create blueprint
bp = Blueprint("auth", __name__, url_prefix="/auth")
@@ -194,257 +186,3 @@ def logout():
return response
@bp.route("/token", methods=["POST"])
def token_endpoint():
"""
IndieAuth token endpoint for exchanging authorization codes for access tokens
Implements the IndieAuth token endpoint as specified in:
https://www.w3.org/TR/indieauth/#token-endpoint
Form parameters (application/x-www-form-urlencoded):
grant_type: Must be "authorization_code"
code: The authorization code received from authorization endpoint
client_id: Client application URL (must match authorization request)
redirect_uri: Redirect URI (must match authorization request)
me: User's profile URL (must match authorization request)
code_verifier: PKCE verifier (optional, required if PKCE was used)
Returns:
200 OK with JSON response on success:
{
"access_token": "xxx",
"token_type": "Bearer",
"scope": "create",
"me": "https://user.example"
}
400 Bad Request with JSON error response on failure:
{
"error": "invalid_grant|invalid_request|invalid_client",
"error_description": "Human-readable error description"
}
"""
# Only accept form-encoded POST requests
if request.content_type and 'application/x-www-form-urlencoded' not in request.content_type:
return jsonify({
"error": "invalid_request",
"error_description": "Content-Type must be application/x-www-form-urlencoded"
}), 400
# Extract parameters from form data
grant_type = request.form.get('grant_type')
code = request.form.get('code')
client_id = request.form.get('client_id')
redirect_uri = request.form.get('redirect_uri')
me = request.form.get('me')
code_verifier = request.form.get('code_verifier')
# Validate required parameters
if not grant_type:
return jsonify({
"error": "invalid_request",
"error_description": "Missing grant_type parameter"
}), 400
if grant_type != 'authorization_code':
return jsonify({
"error": "unsupported_grant_type",
"error_description": f"Unsupported grant_type: {grant_type}"
}), 400
if not code:
return jsonify({
"error": "invalid_request",
"error_description": "Missing code parameter"
}), 400
if not client_id:
return jsonify({
"error": "invalid_request",
"error_description": "Missing client_id parameter"
}), 400
if not redirect_uri:
return jsonify({
"error": "invalid_request",
"error_description": "Missing redirect_uri parameter"
}), 400
if not me:
return jsonify({
"error": "invalid_request",
"error_description": "Missing me parameter"
}), 400
# Exchange authorization code for token
try:
auth_info = exchange_authorization_code(
code=code,
client_id=client_id,
redirect_uri=redirect_uri,
me=me,
code_verifier=code_verifier
)
# IndieAuth spec: MUST NOT issue token if no scope
if not auth_info['scope']:
return jsonify({
"error": "invalid_scope",
"error_description": "Authorization code was issued without scope"
}), 400
# Create access token
access_token = create_access_token(
me=auth_info['me'],
client_id=auth_info['client_id'],
scope=auth_info['scope']
)
# Return token response
return jsonify({
"access_token": access_token,
"token_type": "Bearer",
"scope": auth_info['scope'],
"me": auth_info['me']
}), 200
except InvalidAuthorizationCodeError as e:
current_app.logger.warning(f"Invalid authorization code: {e}")
return jsonify({
"error": "invalid_grant",
"error_description": str(e)
}), 400
except Exception as e:
current_app.logger.error(f"Token endpoint error: {e}")
return jsonify({
"error": "server_error",
"error_description": "An unexpected error occurred"
}), 500
@bp.route("/authorization", methods=["GET", "POST"])
def authorization_endpoint():
"""
IndieAuth authorization endpoint for Micropub client authorization
Implements the IndieAuth authorization endpoint as specified in:
https://www.w3.org/TR/indieauth/#authorization-endpoint
GET: Display authorization consent form
Query parameters:
response_type: Must be "code"
client_id: Client application URL
redirect_uri: Client's callback URL
state: Client's CSRF state token
scope: Space-separated list of requested scopes (optional)
me: User's profile URL (optional)
code_challenge: PKCE challenge (optional)
code_challenge_method: PKCE method, typically "S256" (optional)
POST: Process authorization approval/denial
Form parameters:
approve: "yes" if user approved, anything else is denial
(other parameters inherited from GET via hidden form fields)
Returns:
GET: HTML authorization consent form
POST: Redirect to client's redirect_uri with code and state parameters
"""
if request.method == "GET":
# Extract IndieAuth parameters
response_type = request.args.get('response_type')
client_id = request.args.get('client_id')
redirect_uri = request.args.get('redirect_uri')
state = request.args.get('state')
scope = request.args.get('scope', '')
me_param = request.args.get('me')
code_challenge = request.args.get('code_challenge')
code_challenge_method = request.args.get('code_challenge_method')
# Validate required parameters
if not response_type:
return "Missing response_type parameter", 400
if response_type != 'code':
return f"Unsupported response_type: {response_type}", 400
if not client_id:
return "Missing client_id parameter", 400
if not redirect_uri:
return "Missing redirect_uri parameter", 400
if not state:
return "Missing state parameter", 400
# Validate and filter scope to supported scopes
validated_scope = validate_scope(scope)
# Check if user is logged in as admin
session_token = request.cookies.get("starpunk_session")
if not session_token or not verify_session(session_token):
# Store authorization request in session
session['pending_auth_url'] = request.url
flash("Please log in to authorize this application", "info")
return redirect(url_for('auth.login_form'))
# User is logged in, show authorization consent form
# Use ADMIN_ME as the user's identity
me = current_app.config.get('ADMIN_ME')
return render_template(
'auth/authorize.html',
client_id=client_id,
redirect_uri=redirect_uri,
state=state,
scope=validated_scope,
me=me,
response_type=response_type,
code_challenge=code_challenge,
code_challenge_method=code_challenge_method
)
else: # POST
# User submitted authorization form
approve = request.form.get('approve')
client_id = request.form.get('client_id')
redirect_uri = request.form.get('redirect_uri')
state = request.form.get('state')
scope = request.form.get('scope', '')
me = request.form.get('me')
code_challenge = request.form.get('code_challenge')
code_challenge_method = request.form.get('code_challenge_method')
# Check if user is still logged in
session_token = request.cookies.get("starpunk_session")
if not session_token or not verify_session(session_token):
flash("Session expired, please log in again", "error")
return redirect(url_for('auth.login_form'))
# If user denied, redirect with error
if approve != 'yes':
error_redirect = f"{redirect_uri}?error=access_denied&error_description=User+denied+authorization&state={state}"
return redirect(error_redirect)
# User approved, generate authorization code
try:
auth_code = create_authorization_code(
me=me,
client_id=client_id,
redirect_uri=redirect_uri,
scope=scope,
state=state,
code_challenge=code_challenge,
code_challenge_method=code_challenge_method
)
# Redirect back to client with authorization code
callback_url = f"{redirect_uri}?code={auth_code}&state={state}"
return redirect(callback_url)
except Exception as e:
current_app.logger.error(f"Authorization endpoint error: {e}")
error_redirect = f"{redirect_uri}?error=server_error&error_description=Failed+to+generate+authorization+code&state={state}"
return redirect(error_redirect)

4
starpunk/routes/micropub.py
View File

@@ -28,7 +28,7 @@ from starpunk.micropub import (
handle_create,
handle_query,
)
from starpunk.tokens import verify_token
from starpunk.auth_external import verify_external_token
# Create blueprint
bp = Blueprint("micropub", __name__)
@@ -71,7 +71,7 @@ def micropub_endpoint():
if not token:
return error_response("unauthorized", "No access token provided", 401)
token_info = verify_token(token)
token_info = verify_external_token(token)
if not token_info:
return error_response("unauthorized", "Invalid or expired access token", 401)

412
starpunk/tokens.py
View File

@@ -1,412 +0,0 @@
"""
Token management for Micropub IndieAuth integration
Handles:
- Access token generation and verification
- Authorization code generation and exchange
- Token hashing for secure storage (SHA256)
- Scope validation
- Token expiry management
Security:
- Tokens stored as SHA256 hashes (never plain text)
- Authorization codes use single-use pattern with replay protection
- Optional PKCE support for enhanced security
"""
import hashlib
import secrets
from datetime import datetime, timedelta
from typing import Optional, Dict, Any
from flask import current_app
# V1 supported scopes
SUPPORTED_SCOPES = ["create"]
DEFAULT_SCOPE = "create"
# Token and code expiry defaults
TOKEN_EXPIRY_DAYS = 90
AUTH_CODE_EXPIRY_MINUTES = 10
class TokenError(Exception):
"""Base exception for token-related errors"""
pass
class InvalidTokenError(TokenError):
"""Raised when token is invalid or expired"""
pass
class InvalidAuthorizationCodeError(TokenError):
"""Raised when authorization code is invalid, expired, or already used"""
pass
def generate_token() -> str:
"""
Generate a cryptographically secure random token
Returns:
URL-safe base64-encoded random token (43 characters)
"""
return secrets.token_urlsafe(32)
def hash_token(token: str) -> str:
"""
Generate SHA256 hash of token for secure storage
Args:
token: Plain text token
Returns:
Hexadecimal SHA256 hash
"""
return hashlib.sha256(token.encode()).hexdigest()
def create_access_token(me: str, client_id: str, scope: str) -> str:
"""
Create and store an access token in the database
Args:
me: User's identity URL
client_id: Client application URL
scope: Space-separated list of scopes
Returns:
Plain text access token (return to client, never logged or stored)
Raises:
TokenError: If token creation fails
"""
# Generate token
token = generate_token()
token_hash_value = hash_token(token)
# Calculate expiry
# Use UTC to match SQLite's datetime('now') which returns UTC
expires_at = (datetime.utcnow() + timedelta(days=TOKEN_EXPIRY_DAYS)).strftime('%Y-%m-%d %H:%M:%S')
# Store in database
from starpunk.database import get_db
try:
db = get_db(current_app)
db.execute("""
INSERT INTO tokens (token_hash, me, client_id, scope, expires_at)
VALUES (?, ?, ?, ?, ?)
""", (token_hash_value, me, client_id, scope, expires_at))
db.commit()
current_app.logger.info(
f"Created access token for client_id={client_id}, scope={scope}"
)
return token
except Exception as e:
current_app.logger.error(f"Failed to create access token: {e}")
raise TokenError(f"Failed to create access token: {e}")
def verify_token(token: str) -> Optional[Dict[str, Any]]:
"""
Verify an access token and return token information
Args:
token: Plain text token to verify
Returns:
Dictionary with token info: {me, client_id, scope}
None if token is invalid, expired, or revoked
"""
if not token:
return None
# Hash the token for lookup
token_hash_value = hash_token(token)
from starpunk.database import get_db
try:
db = get_db(current_app)
row = db.execute("""
SELECT me, client_id, scope, id
FROM tokens
WHERE token_hash = ?
AND expires_at > datetime('now')
AND revoked_at IS NULL
""", (token_hash_value,)).fetchone()
if row:
# Update last_used_at
db.execute("""
UPDATE tokens
SET last_used_at = datetime('now')
WHERE id = ?
""", (row['id'],))
db.commit()
return {
'me': row['me'],
'client_id': row['client_id'],
'scope': row['scope']
}
return None
except Exception as e:
current_app.logger.error(f"Token verification failed: {e}")
return None
def revoke_token(token: str) -> bool:
"""
Revoke an access token (soft deletion)
Args:
token: Plain text token to revoke
Returns:
True if token was revoked, False if not found
"""
token_hash_value = hash_token(token)
from starpunk.database import get_db
try:
db = get_db(current_app)
cursor = db.execute("""
UPDATE tokens
SET revoked_at = datetime('now')
WHERE token_hash = ?
AND revoked_at IS NULL
""", (token_hash_value,))
db.commit()
return cursor.rowcount > 0
except Exception as e:
current_app.logger.error(f"Token revocation failed: {e}")
return False
def create_authorization_code(
me: str,
client_id: str,
redirect_uri: str,
scope: str = "",
state: Optional[str] = None,
code_challenge: Optional[str] = None,
code_challenge_method: Optional[str] = None
) -> str:
"""
Create and store an authorization code for token exchange
Args:
me: User's identity URL
client_id: Client application URL
redirect_uri: Client's redirect URI (must match during exchange)
scope: Space-separated list of requested scopes (can be empty)
state: Client's state parameter (optional)
code_challenge: PKCE code challenge (optional)
code_challenge_method: PKCE method, typically 'S256' (optional)
Returns:
Plain text authorization code (return to client)
Raises:
TokenError: If code creation fails
"""
# Generate authorization code
code = generate_token()
code_hash_value = hash_token(code)
# Calculate expiry (short-lived)
# Use UTC to match SQLite's datetime('now') which returns UTC
expires_at = (datetime.utcnow() + timedelta(minutes=AUTH_CODE_EXPIRY_MINUTES)).strftime('%Y-%m-%d %H:%M:%S')
# Store in database
from starpunk.database import get_db
try:
db = get_db(current_app)
db.execute("""
INSERT INTO authorization_codes (
code_hash, me, client_id, redirect_uri, scope, state,
code_challenge, code_challenge_method, expires_at
)
VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
""", (
code_hash_value, me, client_id, redirect_uri, scope, state,
code_challenge, code_challenge_method, expires_at
))
db.commit()
current_app.logger.info(
f"Created authorization code for client_id={client_id}, scope={scope}"
)
return code
except Exception as e:
current_app.logger.error(f"Failed to create authorization code: {e}")
raise TokenError(f"Failed to create authorization code: {e}")
def exchange_authorization_code(
code: str,
client_id: str,
redirect_uri: str,
me: str,
code_verifier: Optional[str] = None
) -> Dict[str, Any]:
"""
Exchange authorization code for access token
Args:
code: Authorization code to exchange
client_id: Client application URL (must match original request)
redirect_uri: Redirect URI (must match original request)
me: User's identity URL (must match original request)
code_verifier: PKCE verifier (required if code_challenge was provided)
Returns:
Dictionary with: {me, client_id, scope}
Raises:
InvalidAuthorizationCodeError: If code is invalid, expired, used, or validation fails
"""
if not code:
raise InvalidAuthorizationCodeError("No authorization code provided")
code_hash_value = hash_token(code)
from starpunk.database import get_db
try:
db = get_db(current_app)
# Look up authorization code
row = db.execute("""
SELECT me, client_id, redirect_uri, scope, code_challenge,
code_challenge_method, used_at
FROM authorization_codes
WHERE code_hash = ?
AND expires_at > datetime('now')
""", (code_hash_value,)).fetchone()
if not row:
raise InvalidAuthorizationCodeError(
"Authorization code is invalid or expired"
)
# Check if already used (prevent replay attacks)
if row['used_at']:
raise InvalidAuthorizationCodeError(
"Authorization code has already been used"
)
# Validate parameters match original authorization request
if row['client_id'] != client_id:
raise InvalidAuthorizationCodeError(
"client_id does not match authorization request"
)
if row['redirect_uri'] != redirect_uri:
raise InvalidAuthorizationCodeError(
"redirect_uri does not match authorization request"
)
if row['me'] != me:
raise InvalidAuthorizationCodeError(
"me parameter does not match authorization request"
)
# Validate PKCE if code_challenge was provided
if row['code_challenge']:
if not code_verifier:
raise InvalidAuthorizationCodeError(
"code_verifier required (PKCE was used during authorization)"
)
# Verify PKCE challenge
if row['code_challenge_method'] == 'S256':
# SHA256 hash of verifier
computed_challenge = hashlib.sha256(
code_verifier.encode()
).hexdigest()
else:
# Plain (not recommended, but spec allows it)
computed_challenge = code_verifier
if computed_challenge != row['code_challenge']:
raise InvalidAuthorizationCodeError(
"code_verifier does not match code_challenge"
)
# Mark code as used
db.execute("""
UPDATE authorization_codes
SET used_at = datetime('now')
WHERE code_hash = ?
""", (code_hash_value,))
db.commit()
# Return authorization info for token creation
return {
'me': row['me'],
'client_id': row['client_id'],
'scope': row['scope']
}
except InvalidAuthorizationCodeError:
# Re-raise validation errors
raise
except Exception as e:
current_app.logger.error(f"Authorization code exchange failed: {e}")
raise InvalidAuthorizationCodeError(f"Code exchange failed: {e}")
def validate_scope(requested_scope: str) -> str:
"""
Validate and filter requested scopes to supported ones
Args:
requested_scope: Space-separated list of requested scopes
Returns:
Space-separated list of valid scopes (may be empty)
"""
if not requested_scope:
return ""
requested = set(requested_scope.split())
supported = set(SUPPORTED_SCOPES)
valid_scopes = requested & supported
return " ".join(sorted(valid_scopes)) if valid_scopes else ""
def check_scope(required: str, granted: str) -> bool:
"""
Check if granted scopes include required scope
Args:
required: Required scope (single scope string)
granted: Granted scopes (space-separated string)
Returns:
True if required scope is in granted scopes
"""
if not granted:
# IndieAuth spec: no scope means no access
return False
granted_scopes = set(granted.split())
return required in granted_scopes