ID Tokens (RS256-signed JWT)

Every token endpoint response that includes the openid scope delivers an ID Token - a compact, URL-safe JSON Web Token signed with the server's RSA-2048 private key using the RS256 algorithm.

The ID Token payload always contains the following registered claims:

• iss - Issuer: the base URL of your Odoo instance.
• sub - Subject: a stable, unique identifier for the authenticated user.
• aud - Audience: the client_id of the Relying Party.
• exp - Expiration time (Unix timestamp).
• iat - Issued-at time (Unix timestamp).
• nonce - Echoed back from the authorization request to prevent replay attacks (when provided).
• at_hash - Left-half SHA-256 hash of the access token (binds ID token to access token).
• c_hash - Left-half SHA-256 hash of the authorization code (in hybrid flows).

Relying Parties verify the token using the public key from /oauth2/jwks. No shared secret is required - any standard JWT library can perform offline verification.

JWKS Endpoint - /oauth2/jwks

The JSON Web Key Set (JWKS) endpoint publishes the RSA public key that clients use to verify ID token signatures. This is the standard mechanism defined in RFC 7517.

Relying Parties fetch this document once (or on key rotation) and cache the public key locally. All subsequent ID token verifications happen offline - no round-trip to Odoo required for each authentication event.

The JWKS document returned by this endpoint includes:

• kty: "RSA" - key type
• use: "sig" - intended use (signature verification)
• alg: "RS256" - signing algorithm
• kid - key identifier (matches the kid header in the ID token JWT)
• n, e - RSA modulus and exponent in base64url encoding

RSA key pairs are automatically generated and stored in Odoo system parameters on first use. No manual key management is required.

OIDC Discovery - /.well-known/openid-configuration

The OpenID Connect Discovery endpoint implements the OpenID Connect Discovery 1.0 specification. It returns a JSON document that fully describes the provider's capabilities - endpoint URLs, supported scopes, response types, signing algorithms, and claim types.

OIDC-aware applications (Keycloak, Auth0, any standards-compliant OIDC client library) only need your Odoo URL to auto-configure themselves. They fetch /.well-known/openid-configuration, discover all endpoint addresses dynamically, and require no manual configuration of individual endpoint URLs.

The discovery document includes:

• issuer - your Odoo base URL
• authorization_endpoint, token_endpoint, userinfo_endpoint, jwks_uri, revocation_endpoint
• response_types_supported - all supported OAuth2 + OIDC response type combinations
• scopes_supported - openid, profile, email, phone
• id_token_signing_alg_values_supported - RS256
• claims_supported - full list of returnable identity claims
• subject_types_supported - public

OIDC UserInfo Endpoint - /oauth2/userinfo

The UserInfo endpoint is an OAuth 2.0 protected resource endpoint defined in OIDC Core 1.0 §5.3. It accepts a valid Access Token via an Authorization: Bearer <token> header (per RFC 6750) and returns a JSON object containing claims about the authenticated user.

The claims returned are filtered by the scopes that were granted when the access token was issued. This allows fine-grained control over which user attributes each application can read:

Nonce Support - Replay Attack Prevention

The nonce is a client-generated, single-use random value included in the authorization request. The OpenID Provider stores the nonce with the authorization code and embeds it verbatim in the issued ID Token's nonce claim.

The Relying Party verifies that the nonce in the received ID Token matches the value it originally sent. This binding between the authentication request and the ID Token is the primary defence against token replay attacks and authorization code injection.

This module correctly propagates the nonce through the full authorization code flow: from the GET /oauth2/authorize consent screen, through the authorization code storage, and into the final JWT id_token.