Add OAuth2/OpenID Connect authorization server

Implement a full OAuth2 2.0 and OpenID Connect 1.0 authorization server with support for authorization code flow (with PKCE), refresh token rotation, device authorization grant, dynamic client registration, token introspection, and token revocation. Includes database schema, coredata layer, service logic, HTTP handlers, OIDC discovery endpoint, and JWKS publishing. Signed-off-by: Bryan Frimin <bryan@getprobo.com>
2026-03-30 14:49:18 +02:00
parent e84094e62c
commit 11770b4058
155 changed files with 14483 additions and 223 deletions
--- a/pkg/iam/oauth2server/id_token.go
+++ b/pkg/iam/oauth2server/id_token.go
@@ -0,0 +1,108 @@
+// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package oauth2server
+
+import (
+	"crypto/rsa"
+	"crypto/sha256"
+	"encoding/base64"
+	"time"
+
+	"go.probo.inc/probo/pkg/coredata"
+	"go.probo.inc/probo/pkg/gid"
+	"go.probo.inc/probo/pkg/uri"
+)
+
+type (
+	// SigningKey pairs an RSA private key with its key ID. All entries are
+	// published in the JWKS endpoint. Keys with Active set to true are
+	// used for signing new tokens; when multiple keys are active, the
+	// service round-robins between them.
+	SigningKey struct {
+		PrivateKey *rsa.PrivateKey
+		KID        string
+		Active     bool
+	}
+
+	IDTokenClaims struct {
+		Issuer        uri.URI               `json:"iss"`
+		Subject       string                `json:"sub"`
+		Audience      string                `json:"aud"`
+		ExpiresAt     int64                 `json:"exp"`
+		IssuedAt      int64                 `json:"iat"`
+		AuthTime      int64                 `json:"auth_time"`
+		Nonce         string                `json:"nonce,omitempty"`
+		AtHash        string                `json:"at_hash,omitempty"`
+		Email         string                `json:"email,omitempty"`
+		EmailVerified *bool                 `json:"email_verified,omitempty"`
+		Name          string                `json:"name,omitempty"`
+		Scope         coredata.OAuth2Scopes `json:"-"`
+	}
+
+	SigningKeys []SigningKey
+)
+
+// ComputeAtHash computes the at_hash claim value for an access token.
+// Per OIDC Core §3.1.3.6: left half of SHA-256 hash, base64url-encoded.
+func ComputeAtHash(accessToken string) string {
+	h := sha256.Sum256([]byte(accessToken))
+	return base64.RawURLEncoding.EncodeToString(h[:16])
+}
+
+func NewIDTokenClaims(
+	issuer uri.URI,
+	identityID gid.GID,
+	clientID gid.GID,
+	authTime time.Time,
+	scopes coredata.OAuth2Scopes,
+	nonce string,
+	accessToken string,
+	email string,
+	emailVerified bool,
+	fullName string,
+	ttl time.Duration,
+) *IDTokenClaims {
+	now := time.Now()
+
+	claims := &IDTokenClaims{
+		Issuer:    issuer,
+		Subject:   identityID.String(),
+		Audience:  clientID.String(),
+		ExpiresAt: now.Add(ttl).Unix(),
+		IssuedAt:  now.Unix(),
+		AuthTime:  authTime.Unix(),
+		Scope:     scopes,
+	}
+
+	if nonce != "" {
+		claims.Nonce = nonce
+	}
+
+	if accessToken != "" {
+		claims.AtHash = ComputeAtHash(accessToken)
+	}
+
+	for _, scope := range scopes {
+		switch scope {
+		case coredata.OAuth2ScopeEmail:
+			claims.Email = email
+			claims.EmailVerified = &emailVerified
+		case coredata.OAuth2ScopeProfile:
+			claims.Name = fullName
+		}
+	}
+
+	return claims
+}