Files
sub2api/backend/internal/handler/auth_oidc_oauth.go
2026-04-20 16:23:42 +08:00

945 lines
28 KiB
Go

package handler
import (
"context"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rsa"
"crypto/sha256"
"encoding/base64"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"log"
"math/big"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"github.com/Wei-Shaw/sub2api/internal/config"
infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
"github.com/Wei-Shaw/sub2api/internal/pkg/oauth"
"github.com/Wei-Shaw/sub2api/internal/pkg/response"
"github.com/Wei-Shaw/sub2api/internal/service"
"github.com/gin-gonic/gin"
"github.com/golang-jwt/jwt/v5"
"github.com/imroc/req/v3"
"github.com/tidwall/gjson"
)
const (
oidcOAuthCookiePath = "/api/v1/auth/oauth/oidc"
oidcOAuthStateCookieName = "oidc_oauth_state"
oidcOAuthVerifierCookie = "oidc_oauth_verifier"
oidcOAuthRedirectCookie = "oidc_oauth_redirect"
oidcOAuthNonceCookie = "oidc_oauth_nonce"
oidcOAuthCookieMaxAgeSec = 10 * 60 // 10 minutes
oidcOAuthDefaultRedirectTo = "/dashboard"
oidcOAuthDefaultFrontendCB = "/auth/oidc/callback"
)
type oidcTokenResponse struct {
AccessToken string `json:"access_token"`
TokenType string `json:"token_type"`
ExpiresIn int64 `json:"expires_in"`
RefreshToken string `json:"refresh_token,omitempty"`
Scope string `json:"scope,omitempty"`
IDToken string `json:"id_token,omitempty"`
}
type oidcTokenExchangeError struct {
StatusCode int
ProviderError string
ProviderDescription string
Body string
}
func (e *oidcTokenExchangeError) Error() string {
if e == nil {
return ""
}
parts := []string{fmt.Sprintf("token exchange status=%d", e.StatusCode)}
if strings.TrimSpace(e.ProviderError) != "" {
parts = append(parts, "error="+strings.TrimSpace(e.ProviderError))
}
if strings.TrimSpace(e.ProviderDescription) != "" {
parts = append(parts, "error_description="+strings.TrimSpace(e.ProviderDescription))
}
return strings.Join(parts, " ")
}
type oidcIDTokenClaims struct {
Email string `json:"email,omitempty"`
EmailVerified *bool `json:"email_verified,omitempty"`
PreferredUsername string `json:"preferred_username,omitempty"`
Name string `json:"name,omitempty"`
Nonce string `json:"nonce,omitempty"`
Azp string `json:"azp,omitempty"`
jwt.RegisteredClaims
}
type oidcUserInfoClaims struct {
Email string
Username string
Subject string
EmailVerified *bool
}
type oidcJWKSet struct {
Keys []oidcJWK `json:"keys"`
}
type oidcJWK struct {
Kty string `json:"kty"`
Kid string `json:"kid"`
Use string `json:"use"`
Alg string `json:"alg"`
N string `json:"n"`
E string `json:"e"`
Crv string `json:"crv"`
X string `json:"x"`
Y string `json:"y"`
}
// OIDCOAuthStart 启动通用 OIDC OAuth 登录流程。
// GET /api/v1/auth/oauth/oidc/start?redirect=/dashboard
func (h *AuthHandler) OIDCOAuthStart(c *gin.Context) {
cfg, err := h.getOIDCOAuthConfig(c.Request.Context())
if err != nil {
response.ErrorFrom(c, err)
return
}
state, err := oauth.GenerateState()
if err != nil {
response.ErrorFrom(c, infraerrors.InternalServer("OAUTH_STATE_GEN_FAILED", "failed to generate oauth state").WithCause(err))
return
}
redirectTo := sanitizeFrontendRedirectPath(c.Query("redirect"))
if redirectTo == "" {
redirectTo = oidcOAuthDefaultRedirectTo
}
browserSessionKey, err := generateOAuthPendingBrowserSession()
if err != nil {
response.ErrorFrom(c, infraerrors.InternalServer("OAUTH_BROWSER_SESSION_GEN_FAILED", "failed to generate oauth browser session").WithCause(err))
return
}
secureCookie := isRequestHTTPS(c)
oidcSetCookie(c, oidcOAuthStateCookieName, encodeCookieValue(state), oidcOAuthCookieMaxAgeSec, secureCookie)
oidcSetCookie(c, oidcOAuthRedirectCookie, encodeCookieValue(redirectTo), oidcOAuthCookieMaxAgeSec, secureCookie)
setOAuthPendingBrowserCookie(c, browserSessionKey, secureCookie)
clearOAuthPendingSessionCookie(c, secureCookie)
codeChallenge := ""
verifier, genErr := oauth.GenerateCodeVerifier()
if genErr != nil {
response.ErrorFrom(c, infraerrors.InternalServer("OAUTH_PKCE_GEN_FAILED", "failed to generate pkce verifier").WithCause(genErr))
return
}
codeChallenge = oauth.GenerateCodeChallenge(verifier)
oidcSetCookie(c, oidcOAuthVerifierCookie, encodeCookieValue(verifier), oidcOAuthCookieMaxAgeSec, secureCookie)
nonce := ""
nonce, err = oauth.GenerateState()
if err != nil {
response.ErrorFrom(c, infraerrors.InternalServer("OAUTH_NONCE_GEN_FAILED", "failed to generate oauth nonce").WithCause(err))
return
}
oidcSetCookie(c, oidcOAuthNonceCookie, encodeCookieValue(nonce), oidcOAuthCookieMaxAgeSec, secureCookie)
redirectURI := strings.TrimSpace(cfg.RedirectURL)
if redirectURI == "" {
response.ErrorFrom(c, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth redirect url not configured"))
return
}
authURL, err := buildOIDCAuthorizeURL(cfg, state, nonce, codeChallenge, redirectURI)
if err != nil {
response.ErrorFrom(c, infraerrors.InternalServer("OAUTH_BUILD_URL_FAILED", "failed to build oauth authorization url").WithCause(err))
return
}
c.Redirect(http.StatusFound, authURL)
}
// OIDCOAuthCallback 处理 OIDC 回调:校验 id_token、创建/登录用户并重定向到前端。
// GET /api/v1/auth/oauth/oidc/callback?code=...&state=...
func (h *AuthHandler) OIDCOAuthCallback(c *gin.Context) {
cfg, cfgErr := h.getOIDCOAuthConfig(c.Request.Context())
if cfgErr != nil {
response.ErrorFrom(c, cfgErr)
return
}
frontendCallback := strings.TrimSpace(cfg.FrontendRedirectURL)
if frontendCallback == "" {
frontendCallback = oidcOAuthDefaultFrontendCB
}
if providerErr := strings.TrimSpace(c.Query("error")); providerErr != "" {
redirectOAuthError(c, frontendCallback, "provider_error", providerErr, c.Query("error_description"))
return
}
code := strings.TrimSpace(c.Query("code"))
state := strings.TrimSpace(c.Query("state"))
if code == "" || state == "" {
redirectOAuthError(c, frontendCallback, "missing_params", "missing code/state", "")
return
}
secureCookie := isRequestHTTPS(c)
defer func() {
oidcClearCookie(c, oidcOAuthStateCookieName, secureCookie)
oidcClearCookie(c, oidcOAuthVerifierCookie, secureCookie)
oidcClearCookie(c, oidcOAuthRedirectCookie, secureCookie)
oidcClearCookie(c, oidcOAuthNonceCookie, secureCookie)
}()
expectedState, err := readCookieDecoded(c, oidcOAuthStateCookieName)
if err != nil || expectedState == "" || state != expectedState {
redirectOAuthError(c, frontendCallback, "invalid_state", "invalid oauth state", "")
return
}
redirectTo, _ := readCookieDecoded(c, oidcOAuthRedirectCookie)
redirectTo = sanitizeFrontendRedirectPath(redirectTo)
if redirectTo == "" {
redirectTo = oidcOAuthDefaultRedirectTo
}
browserSessionKey, _ := readOAuthPendingBrowserCookie(c)
if strings.TrimSpace(browserSessionKey) == "" {
redirectOAuthError(c, frontendCallback, "missing_browser_session", "missing oauth browser session", "")
return
}
codeVerifier := ""
codeVerifier, _ = readCookieDecoded(c, oidcOAuthVerifierCookie)
if codeVerifier == "" {
redirectOAuthError(c, frontendCallback, "missing_verifier", "missing pkce verifier", "")
return
}
expectedNonce := ""
expectedNonce, _ = readCookieDecoded(c, oidcOAuthNonceCookie)
if expectedNonce == "" {
redirectOAuthError(c, frontendCallback, "missing_nonce", "missing oauth nonce", "")
return
}
redirectURI := strings.TrimSpace(cfg.RedirectURL)
if redirectURI == "" {
redirectOAuthError(c, frontendCallback, "config_error", "oauth redirect url not configured", "")
return
}
tokenResp, err := oidcExchangeCode(c.Request.Context(), cfg, code, redirectURI, codeVerifier)
if err != nil {
description := ""
var exchangeErr *oidcTokenExchangeError
if errors.As(err, &exchangeErr) && exchangeErr != nil {
log.Printf(
"[OIDC OAuth] token exchange failed: status=%d provider_error=%q provider_description=%q body=%s",
exchangeErr.StatusCode,
exchangeErr.ProviderError,
exchangeErr.ProviderDescription,
truncateLogValue(exchangeErr.Body, 2048),
)
description = exchangeErr.Error()
} else {
log.Printf("[OIDC OAuth] token exchange failed: %v", err)
description = err.Error()
}
redirectOAuthError(c, frontendCallback, "token_exchange_failed", "failed to exchange oauth code", singleLine(description))
return
}
if strings.TrimSpace(tokenResp.IDToken) == "" {
redirectOAuthError(c, frontendCallback, "missing_id_token", "missing id_token", "")
return
}
idClaims, err := oidcParseAndValidateIDToken(c.Request.Context(), cfg, tokenResp.IDToken, expectedNonce)
if err != nil {
log.Printf("[OIDC OAuth] id_token validation failed: %v", err)
redirectOAuthError(c, frontendCallback, "invalid_id_token", "failed to validate id_token", "")
return
}
userInfoClaims, err := oidcFetchUserInfo(c.Request.Context(), cfg, tokenResp)
if err != nil {
log.Printf("[OIDC OAuth] userinfo fetch failed: %v", err)
redirectOAuthError(c, frontendCallback, "userinfo_failed", "failed to fetch user info", "")
return
}
subject := strings.TrimSpace(idClaims.Subject)
if subject == "" {
subject = strings.TrimSpace(userInfoClaims.Subject)
}
if subject == "" {
redirectOAuthError(c, frontendCallback, "missing_subject", "missing subject claim", "")
return
}
issuer := strings.TrimSpace(idClaims.Issuer)
if issuer == "" {
issuer = strings.TrimSpace(cfg.IssuerURL)
}
if issuer == "" {
redirectOAuthError(c, frontendCallback, "missing_issuer", "missing issuer claim", "")
return
}
emailVerified := userInfoClaims.EmailVerified
if emailVerified == nil {
emailVerified = idClaims.EmailVerified
}
if cfg.RequireEmailVerified {
if emailVerified == nil || !*emailVerified {
redirectOAuthError(c, frontendCallback, "email_not_verified", "email is not verified", "")
return
}
}
if userInfoClaims.Subject != "" && idClaims.Subject != "" && strings.TrimSpace(userInfoClaims.Subject) != strings.TrimSpace(idClaims.Subject) {
redirectOAuthError(c, frontendCallback, "subject_mismatch", "userinfo subject does not match id_token", "")
return
}
identityKey := oidcIdentityKey(issuer, subject)
email := oidcSyntheticEmailFromIdentityKey(identityKey)
username := firstNonEmpty(
userInfoClaims.Username,
idClaims.PreferredUsername,
idClaims.Name,
oidcFallbackUsername(subject),
)
// 传入空邀请码;如果需要邀请码,服务层返回 ErrOAuthInvitationRequired
tokenPair, _, err := h.authService.LoginOrRegisterOAuthWithTokenPair(c.Request.Context(), email, username, "")
if err != nil {
if errors.Is(err, service.ErrOAuthInvitationRequired) {
if err := h.createOAuthPendingSession(c, oauthPendingSessionPayload{
Intent: "login",
Identity: service.PendingAuthIdentityKey{
ProviderType: "oidc",
ProviderKey: issuer,
ProviderSubject: subject,
},
ResolvedEmail: email,
RedirectTo: redirectTo,
BrowserSessionKey: browserSessionKey,
UpstreamIdentityClaims: map[string]any{
"email": email,
"username": username,
"subject": subject,
"issuer": issuer,
"email_verified": emailVerified != nil && *emailVerified,
"provider_fallback": strings.TrimSpace(cfg.ProviderName),
},
CompletionResponse: map[string]any{
"error": "invitation_required",
"redirect": redirectTo,
},
}); err != nil {
redirectOAuthError(c, frontendCallback, "session_error", "failed to continue oauth login", "")
return
}
redirectToFrontendCallback(c, frontendCallback)
return
}
redirectOAuthError(c, frontendCallback, "login_failed", infraerrors.Reason(err), infraerrors.Message(err))
return
}
if err := h.createOAuthPendingSession(c, oauthPendingSessionPayload{
Intent: "login",
Identity: service.PendingAuthIdentityKey{
ProviderType: "oidc",
ProviderKey: issuer,
ProviderSubject: subject,
},
ResolvedEmail: email,
RedirectTo: redirectTo,
BrowserSessionKey: browserSessionKey,
UpstreamIdentityClaims: map[string]any{
"email": email,
"username": username,
"subject": subject,
"issuer": issuer,
"email_verified": emailVerified != nil && *emailVerified,
"provider_fallback": strings.TrimSpace(cfg.ProviderName),
},
CompletionResponse: map[string]any{
"access_token": tokenPair.AccessToken,
"refresh_token": tokenPair.RefreshToken,
"expires_in": tokenPair.ExpiresIn,
"token_type": "Bearer",
"redirect": redirectTo,
},
}); err != nil {
redirectOAuthError(c, frontendCallback, "session_error", "failed to continue oauth login", "")
return
}
redirectToFrontendCallback(c, frontendCallback)
}
type completeOIDCOAuthRequest struct {
InvitationCode string `json:"invitation_code" binding:"required"`
}
// CompleteOIDCOAuthRegistration completes a pending OAuth registration by validating
// the invitation code and creating the user account.
// POST /api/v1/auth/oauth/oidc/complete-registration
func (h *AuthHandler) CompleteOIDCOAuthRegistration(c *gin.Context) {
var req completeOIDCOAuthRequest
if err := c.ShouldBindJSON(&req); err != nil {
c.JSON(http.StatusBadRequest, gin.H{"error": "INVALID_REQUEST", "message": err.Error()})
return
}
secureCookie := isRequestHTTPS(c)
sessionToken, err := readOAuthPendingSessionCookie(c)
if err != nil {
clearOAuthPendingSessionCookie(c, secureCookie)
clearOAuthPendingBrowserCookie(c, secureCookie)
response.ErrorFrom(c, service.ErrPendingAuthSessionNotFound)
return
}
browserSessionKey, err := readOAuthPendingBrowserCookie(c)
if err != nil {
clearOAuthPendingSessionCookie(c, secureCookie)
clearOAuthPendingBrowserCookie(c, secureCookie)
response.ErrorFrom(c, service.ErrPendingAuthBrowserMismatch)
return
}
pendingSvc, err := h.pendingIdentityService()
if err != nil {
response.ErrorFrom(c, err)
return
}
session, err := pendingSvc.GetBrowserSession(c.Request.Context(), sessionToken, browserSessionKey)
if err != nil {
clearOAuthPendingSessionCookie(c, secureCookie)
clearOAuthPendingBrowserCookie(c, secureCookie)
response.ErrorFrom(c, err)
return
}
email := strings.TrimSpace(session.ResolvedEmail)
username := pendingSessionStringValue(session.UpstreamIdentityClaims, "username")
if email == "" || username == "" {
response.ErrorFrom(c, infraerrors.BadRequest("PENDING_AUTH_SESSION_INVALID", "pending auth registration context is invalid"))
return
}
tokenPair, _, err := h.authService.LoginOrRegisterOAuthWithTokenPair(c.Request.Context(), email, username, req.InvitationCode)
if err != nil {
response.ErrorFrom(c, err)
return
}
if _, err := pendingSvc.ConsumeBrowserSession(c.Request.Context(), sessionToken, browserSessionKey); err != nil {
clearOAuthPendingSessionCookie(c, secureCookie)
clearOAuthPendingBrowserCookie(c, secureCookie)
response.ErrorFrom(c, err)
return
}
clearOAuthPendingSessionCookie(c, secureCookie)
clearOAuthPendingBrowserCookie(c, secureCookie)
c.JSON(http.StatusOK, gin.H{
"access_token": tokenPair.AccessToken,
"refresh_token": tokenPair.RefreshToken,
"expires_in": tokenPair.ExpiresIn,
"token_type": "Bearer",
})
}
func (h *AuthHandler) getOIDCOAuthConfig(ctx context.Context) (config.OIDCConnectConfig, error) {
if h != nil && h.settingSvc != nil {
return h.settingSvc.GetOIDCConnectOAuthConfig(ctx)
}
if h == nil || h.cfg == nil {
return config.OIDCConnectConfig{}, infraerrors.ServiceUnavailable("CONFIG_NOT_READY", "config not loaded")
}
if !h.cfg.OIDC.Enabled {
return config.OIDCConnectConfig{}, infraerrors.NotFound("OAUTH_DISABLED", "oauth login is disabled")
}
return h.cfg.OIDC, nil
}
func oidcExchangeCode(
ctx context.Context,
cfg config.OIDCConnectConfig,
code string,
redirectURI string,
codeVerifier string,
) (*oidcTokenResponse, error) {
client := req.C().SetTimeout(30 * time.Second)
form := url.Values{}
form.Set("grant_type", "authorization_code")
form.Set("client_id", cfg.ClientID)
form.Set("code", code)
form.Set("redirect_uri", redirectURI)
form.Set("code_verifier", codeVerifier)
r := client.R().
SetContext(ctx).
SetHeader("Accept", "application/json")
switch strings.ToLower(strings.TrimSpace(cfg.TokenAuthMethod)) {
case "", "client_secret_post":
form.Set("client_secret", cfg.ClientSecret)
case "client_secret_basic":
r.SetBasicAuth(cfg.ClientID, cfg.ClientSecret)
case "none":
default:
return nil, fmt.Errorf("unsupported token_auth_method: %s", cfg.TokenAuthMethod)
}
resp, err := r.SetFormDataFromValues(form).Post(cfg.TokenURL)
if err != nil {
return nil, fmt.Errorf("request token: %w", err)
}
body := strings.TrimSpace(resp.String())
if !resp.IsSuccessState() {
providerErr, providerDesc := parseOAuthProviderError(body)
return nil, &oidcTokenExchangeError{
StatusCode: resp.StatusCode,
ProviderError: providerErr,
ProviderDescription: providerDesc,
Body: body,
}
}
tokenResp, ok := oidcParseTokenResponse(body)
if !ok {
return nil, &oidcTokenExchangeError{StatusCode: resp.StatusCode, Body: body}
}
if strings.TrimSpace(tokenResp.TokenType) == "" {
tokenResp.TokenType = "Bearer"
}
if strings.TrimSpace(tokenResp.AccessToken) == "" && strings.TrimSpace(tokenResp.IDToken) == "" {
return nil, &oidcTokenExchangeError{StatusCode: resp.StatusCode, Body: body}
}
return tokenResp, nil
}
func oidcParseTokenResponse(body string) (*oidcTokenResponse, bool) {
body = strings.TrimSpace(body)
if body == "" {
return nil, false
}
accessToken := strings.TrimSpace(getGJSON(body, "access_token"))
idToken := strings.TrimSpace(getGJSON(body, "id_token"))
if accessToken != "" || idToken != "" {
tokenType := strings.TrimSpace(getGJSON(body, "token_type"))
refreshToken := strings.TrimSpace(getGJSON(body, "refresh_token"))
scope := strings.TrimSpace(getGJSON(body, "scope"))
expiresIn := gjson.Get(body, "expires_in").Int()
return &oidcTokenResponse{
AccessToken: accessToken,
TokenType: tokenType,
ExpiresIn: expiresIn,
RefreshToken: refreshToken,
Scope: scope,
IDToken: idToken,
}, true
}
values, err := url.ParseQuery(body)
if err != nil {
return nil, false
}
accessToken = strings.TrimSpace(values.Get("access_token"))
idToken = strings.TrimSpace(values.Get("id_token"))
if accessToken == "" && idToken == "" {
return nil, false
}
expiresIn := int64(0)
if raw := strings.TrimSpace(values.Get("expires_in")); raw != "" {
if v, parseErr := strconv.ParseInt(raw, 10, 64); parseErr == nil {
expiresIn = v
}
}
return &oidcTokenResponse{
AccessToken: accessToken,
TokenType: strings.TrimSpace(values.Get("token_type")),
ExpiresIn: expiresIn,
RefreshToken: strings.TrimSpace(values.Get("refresh_token")),
Scope: strings.TrimSpace(values.Get("scope")),
IDToken: idToken,
}, true
}
func oidcFetchUserInfo(
ctx context.Context,
cfg config.OIDCConnectConfig,
token *oidcTokenResponse,
) (*oidcUserInfoClaims, error) {
if strings.TrimSpace(cfg.UserInfoURL) == "" {
return &oidcUserInfoClaims{}, nil
}
if token == nil || strings.TrimSpace(token.AccessToken) == "" {
return nil, errors.New("missing access_token for userinfo request")
}
client := req.C().SetTimeout(30 * time.Second)
authorization, err := buildBearerAuthorization(token.TokenType, token.AccessToken)
if err != nil {
return nil, fmt.Errorf("invalid token for userinfo request: %w", err)
}
resp, err := client.R().
SetContext(ctx).
SetHeader("Accept", "application/json").
SetHeader("Authorization", authorization).
Get(cfg.UserInfoURL)
if err != nil {
return nil, fmt.Errorf("request userinfo: %w", err)
}
if !resp.IsSuccessState() {
return nil, fmt.Errorf("userinfo status=%d", resp.StatusCode)
}
return oidcParseUserInfo(resp.String(), cfg), nil
}
func oidcParseUserInfo(body string, cfg config.OIDCConnectConfig) *oidcUserInfoClaims {
claims := &oidcUserInfoClaims{}
claims.Email = firstNonEmpty(
getGJSON(body, cfg.UserInfoEmailPath),
getGJSON(body, "email"),
getGJSON(body, "user.email"),
getGJSON(body, "data.email"),
getGJSON(body, "attributes.email"),
)
claims.Username = firstNonEmpty(
getGJSON(body, cfg.UserInfoUsernamePath),
getGJSON(body, "preferred_username"),
getGJSON(body, "username"),
getGJSON(body, "name"),
getGJSON(body, "user.username"),
getGJSON(body, "user.name"),
)
claims.Subject = firstNonEmpty(
getGJSON(body, cfg.UserInfoIDPath),
getGJSON(body, "sub"),
getGJSON(body, "id"),
getGJSON(body, "user_id"),
getGJSON(body, "uid"),
getGJSON(body, "user.id"),
)
if verified, ok := getGJSONBool(body, "email_verified"); ok {
claims.EmailVerified = &verified
}
claims.Email = strings.TrimSpace(claims.Email)
claims.Username = strings.TrimSpace(claims.Username)
claims.Subject = strings.TrimSpace(claims.Subject)
return claims
}
func getGJSONBool(body string, path string) (bool, bool) {
path = strings.TrimSpace(path)
if path == "" {
return false, false
}
res := gjson.Get(body, path)
if !res.Exists() {
return false, false
}
return res.Bool(), true
}
func buildOIDCAuthorizeURL(cfg config.OIDCConnectConfig, state, nonce, codeChallenge, redirectURI string) (string, error) {
u, err := url.Parse(cfg.AuthorizeURL)
if err != nil {
return "", fmt.Errorf("parse authorize_url: %w", err)
}
q := u.Query()
q.Set("response_type", "code")
q.Set("client_id", cfg.ClientID)
q.Set("redirect_uri", redirectURI)
if strings.TrimSpace(cfg.Scopes) != "" {
q.Set("scope", cfg.Scopes)
}
q.Set("state", state)
q.Set("nonce", nonce)
q.Set("code_challenge", codeChallenge)
q.Set("code_challenge_method", "S256")
u.RawQuery = q.Encode()
return u.String(), nil
}
func oidcParseAndValidateIDToken(ctx context.Context, cfg config.OIDCConnectConfig, idToken string, expectedNonce string) (*oidcIDTokenClaims, error) {
idToken = strings.TrimSpace(idToken)
if idToken == "" {
return nil, errors.New("missing id_token")
}
allowed := oidcAllowedSigningAlgs(cfg.AllowedSigningAlgs)
if len(allowed) == 0 {
return nil, errors.New("empty allowed signing algorithms")
}
jwks, err := oidcFetchJWKSet(ctx, cfg.JWKSURL)
if err != nil {
return nil, err
}
leeway := time.Duration(cfg.ClockSkewSeconds) * time.Second
claims := &oidcIDTokenClaims{}
parsed, err := jwt.ParseWithClaims(
idToken,
claims,
func(token *jwt.Token) (any, error) {
alg := strings.TrimSpace(token.Method.Alg())
if !containsString(allowed, alg) {
return nil, fmt.Errorf("unexpected signing algorithm: %s", alg)
}
kid, _ := token.Header["kid"].(string)
return oidcFindPublicKey(jwks, strings.TrimSpace(kid), alg)
},
jwt.WithValidMethods(allowed),
jwt.WithAudience(cfg.ClientID),
jwt.WithIssuer(cfg.IssuerURL),
jwt.WithLeeway(leeway),
)
if err != nil {
return nil, err
}
if !parsed.Valid {
return nil, errors.New("id_token invalid")
}
if strings.TrimSpace(claims.Subject) == "" {
return nil, errors.New("id_token missing sub")
}
if expectedNonce != "" && strings.TrimSpace(claims.Nonce) != strings.TrimSpace(expectedNonce) {
return nil, errors.New("id_token nonce mismatch")
}
if len(claims.Audience) > 1 {
if strings.TrimSpace(claims.Azp) == "" || strings.TrimSpace(claims.Azp) != strings.TrimSpace(cfg.ClientID) {
return nil, errors.New("id_token azp mismatch")
}
}
return claims, nil
}
func oidcAllowedSigningAlgs(raw string) []string {
if strings.TrimSpace(raw) == "" {
return []string{"RS256", "ES256", "PS256"}
}
seen := make(map[string]struct{})
out := make([]string, 0, 4)
for _, part := range strings.Split(raw, ",") {
alg := strings.ToUpper(strings.TrimSpace(part))
if alg == "" {
continue
}
if _, ok := seen[alg]; ok {
continue
}
seen[alg] = struct{}{}
out = append(out, alg)
}
return out
}
func oidcFetchJWKSet(ctx context.Context, jwksURL string) (*oidcJWKSet, error) {
jwksURL = strings.TrimSpace(jwksURL)
if jwksURL == "" {
return nil, errors.New("missing jwks_url")
}
resp, err := req.C().
SetTimeout(30*time.Second).
R().
SetContext(ctx).
SetHeader("Accept", "application/json").
Get(jwksURL)
if err != nil {
return nil, fmt.Errorf("request jwks: %w", err)
}
if !resp.IsSuccessState() {
return nil, fmt.Errorf("jwks status=%d", resp.StatusCode)
}
set := &oidcJWKSet{}
if err := json.Unmarshal(resp.Bytes(), set); err != nil {
return nil, fmt.Errorf("parse jwks: %w", err)
}
if len(set.Keys) == 0 {
return nil, errors.New("jwks empty keys")
}
return set, nil
}
func oidcFindPublicKey(set *oidcJWKSet, kid, alg string) (any, error) {
if set == nil {
return nil, errors.New("jwks not loaded")
}
alg = strings.ToUpper(strings.TrimSpace(alg))
kid = strings.TrimSpace(kid)
var lastErr error
for i := range set.Keys {
k := set.Keys[i]
if strings.TrimSpace(k.Use) != "" && !strings.EqualFold(strings.TrimSpace(k.Use), "sig") {
continue
}
if kid != "" && strings.TrimSpace(k.Kid) != kid {
continue
}
if strings.TrimSpace(k.Alg) != "" && !strings.EqualFold(strings.TrimSpace(k.Alg), alg) {
continue
}
pk, err := k.publicKey()
if err != nil {
lastErr = err
continue
}
if pk != nil {
return pk, nil
}
}
if lastErr != nil {
return nil, lastErr
}
if kid != "" {
return nil, fmt.Errorf("jwk not found for kid=%s", kid)
}
return nil, errors.New("jwk not found")
}
func (k oidcJWK) publicKey() (any, error) {
switch strings.ToUpper(strings.TrimSpace(k.Kty)) {
case "RSA":
n, err := decodeBase64URLBigInt(k.N)
if err != nil {
return nil, fmt.Errorf("decode rsa n: %w", err)
}
eBytes, err := base64.RawURLEncoding.DecodeString(strings.TrimSpace(k.E))
if err != nil {
return nil, fmt.Errorf("decode rsa e: %w", err)
}
if len(eBytes) == 0 {
return nil, errors.New("empty rsa e")
}
e := 0
for _, b := range eBytes {
e = (e << 8) | int(b)
}
if e <= 0 {
return nil, errors.New("invalid rsa exponent")
}
if n.Sign() <= 0 {
return nil, errors.New("invalid rsa modulus")
}
return &rsa.PublicKey{N: n, E: e}, nil
case "EC":
var curve elliptic.Curve
switch strings.TrimSpace(k.Crv) {
case "P-256":
curve = elliptic.P256()
case "P-384":
curve = elliptic.P384()
case "P-521":
curve = elliptic.P521()
default:
return nil, fmt.Errorf("unsupported ec curve: %s", k.Crv)
}
x, err := decodeBase64URLBigInt(k.X)
if err != nil {
return nil, fmt.Errorf("decode ec x: %w", err)
}
y, err := decodeBase64URLBigInt(k.Y)
if err != nil {
return nil, fmt.Errorf("decode ec y: %w", err)
}
if !curve.IsOnCurve(x, y) {
return nil, errors.New("ec point is not on curve")
}
return &ecdsa.PublicKey{Curve: curve, X: x, Y: y}, nil
default:
return nil, fmt.Errorf("unsupported jwk kty: %s", k.Kty)
}
}
func decodeBase64URLBigInt(raw string) (*big.Int, error) {
buf, err := base64.RawURLEncoding.DecodeString(strings.TrimSpace(raw))
if err != nil {
return nil, err
}
if len(buf) == 0 {
return nil, errors.New("empty value")
}
return new(big.Int).SetBytes(buf), nil
}
func containsString(values []string, target string) bool {
target = strings.TrimSpace(target)
for _, v := range values {
if strings.EqualFold(strings.TrimSpace(v), target) {
return true
}
}
return false
}
func oidcIdentityKey(issuer, subject string) string {
issuer = strings.TrimSpace(strings.ToLower(issuer))
subject = strings.TrimSpace(subject)
return issuer + "\x1f" + subject
}
func oidcSyntheticEmailFromIdentityKey(identityKey string) string {
identityKey = strings.TrimSpace(identityKey)
if identityKey == "" {
return ""
}
sum := sha256.Sum256([]byte(identityKey))
return "oidc-" + hex.EncodeToString(sum[:16]) + service.OIDCConnectSyntheticEmailDomain
}
func oidcFallbackUsername(subject string) string {
subject = strings.TrimSpace(subject)
if subject == "" {
return "oidc_user"
}
sum := sha256.Sum256([]byte(subject))
return "oidc_" + hex.EncodeToString(sum[:])[:12]
}
func oidcSetCookie(c *gin.Context, name, value string, maxAgeSec int, secure bool) {
http.SetCookie(c.Writer, &http.Cookie{
Name: name,
Value: value,
Path: oidcOAuthCookiePath,
MaxAge: maxAgeSec,
HttpOnly: true,
Secure: secure,
SameSite: http.SameSiteLaxMode,
})
}
func oidcClearCookie(c *gin.Context, name string, secure bool) {
http.SetCookie(c.Writer, &http.Cookie{
Name: name,
Value: "",
Path: oidcOAuthCookiePath,
MaxAge: -1,
HttpOnly: true,
Secure: secure,
SameSite: http.SameSiteLaxMode,
})
}