refactor(server): merge authserver implementation

server/internal/auth/jwt.go

@@ -0,0 +1,159 @@
+package auth
+
+import (
+	"crypto/rsa"
+	"errors"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+type Claims struct {
+	UserID   uint64 `json:"uid"`
+	Username string `json:"username"`
+	Email    string `json:"email"`
+	IsAdmin  bool   `json:"admin"`
+	jwt.RegisteredClaims
+}
+
+type OAuthCodeClaims struct {
+	UserID      uint64 `json:"uid"`
+	ClientID    string `json:"client_id"`
+	RedirectURI string `json:"redirect_uri"`
+	Scope       string `json:"scope"`
+	Nonce       string `json:"nonce,omitempty"`
+	jwt.RegisteredClaims
+}
+
+type IDTokenClaims struct {
+	UserID        uint64 `json:"uid"`
+	Username      string `json:"preferred_username"`
+	Email         string `json:"email"`
+	EmailVerified bool   `json:"email_verified"`
+	Name          string `json:"name"`
+	Nonce         string `json:"nonce,omitempty"`
+	jwt.RegisteredClaims
+}
+
+func Sign(secret, issuer string, ttl time.Duration, userID uint64, username, email string, isAdmin bool) (string, string, time.Time, error) {
+	now := time.Now()
+	expiresAt := now.Add(ttl)
+	tokenID := randomID()
+	claims := Claims{
+		UserID:   userID,
+		Username: username,
+		Email:    email,
+		IsAdmin:  isAdmin,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ID:        tokenID,
+			Issuer:    issuer,
+			Subject:   username,
+			Audience:  []string{"authserver"},
+			IssuedAt:  jwt.NewNumericDate(now),
+			ExpiresAt: jwt.NewNumericDate(expiresAt),
+		},
+	}
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	signed, err := token.SignedString([]byte(secret))
+	return signed, tokenID, expiresAt, err
+}
+
+func SignOAuthCode(secret, issuer string, ttl time.Duration, userID uint64, clientID, redirectURI, scope, nonce string) (string, string, time.Time, error) {
+	now := time.Now()
+	expiresAt := now.Add(ttl)
+	codeID := randomID()
+	claims := OAuthCodeClaims{
+		UserID:      userID,
+		ClientID:    clientID,
+		RedirectURI: redirectURI,
+		Scope:       scope,
+		Nonce:       nonce,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ID:        codeID,
+			Issuer:    issuer,
+			Subject:   clientID,
+			Audience:  []string{"oauth-code"},
+			IssuedAt:  jwt.NewNumericDate(now),
+			ExpiresAt: jwt.NewNumericDate(expiresAt),
+		},
+	}
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	signed, err := token.SignedString([]byte(secret))
+	return signed, codeID, expiresAt, err
+}
+
+func SignIDToken(privateKey *rsa.PrivateKey, keyID, issuer, clientID string, ttl time.Duration, userID uint64, username, email, name, nonce string) (string, time.Time, error) {
+	now := time.Now()
+	expiresAt := now.Add(ttl)
+	subject := email
+	if subject == "" {
+		subject = username
+	}
+	claims := IDTokenClaims{
+		UserID:        userID,
+		Username:      username,
+		Email:         email,
+		EmailVerified: email != "",
+		Name:          name,
+		Nonce:         nonce,
+		RegisteredClaims: jwt.RegisteredClaims{
+			Issuer:    issuer,
+			Subject:   subject,
+			Audience:  []string{clientID},
+			IssuedAt:  jwt.NewNumericDate(now),
+			ExpiresAt: jwt.NewNumericDate(expiresAt),
+		},
+	}
+	token := jwt.NewWithClaims(jwt.SigningMethodRS256, claims)
+	if keyID != "" {
+		token.Header["kid"] = keyID
+	}
+	signed, err := token.SignedString(privateKey)
+	return signed, expiresAt, err
+}
+
+func Parse(secret string, tokenValue string) (*Claims, error) {
+	token, err := jwt.ParseWithClaims(tokenValue, &Claims{}, func(token *jwt.Token) (any, error) {
+		if token.Method != jwt.SigningMethodHS256 {
+			return nil, errors.New("unexpected jwt signing method")
+		}
+		return []byte(secret), nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	claims, ok := token.Claims.(*Claims)
+	if !ok || !token.Valid {
+		return nil, errors.New("invalid jwt claims")
+	}
+	return claims, nil
+}
+
+func ParseOAuthCode(secret string, tokenValue string) (*OAuthCodeClaims, error) {
+	token, err := jwt.ParseWithClaims(tokenValue, &OAuthCodeClaims{}, func(token *jwt.Token) (any, error) {
+		if token.Method != jwt.SigningMethodHS256 {
+			return nil, errors.New("unexpected jwt signing method")
+		}
+		return []byte(secret), nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	claims, ok := token.Claims.(*OAuthCodeClaims)
+	if !ok || !token.Valid {
+		return nil, errors.New("invalid oauth code claims")
+	}
+	if !claimStringsContains(claims.Audience, "oauth-code") {
+		return nil, errors.New("invalid oauth code audience")
+	}
+	return claims, nil
+}
+
+func claimStringsContains(values jwt.ClaimStrings, target string) bool {
+	for _, value := range values {
+		if value == target {
+			return true
+		}
+	}
+	return false
+}

server/internal/auth/oidc_key.go

@@ -0,0 +1,64 @@
+package auth
+
+import (
+	"crypto/rsa"
+	"crypto/sha256"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/pem"
+	"errors"
+	"math/big"
+	"os"
+)
+
+type JWK struct {
+	KeyType   string `json:"kty"`
+	Use       string `json:"use"`
+	KeyID     string `json:"kid"`
+	Algorithm string `json:"alg"`
+	Modulus   string `json:"n"`
+	Exponent  string `json:"e"`
+}
+
+func LoadRSAPrivateKey(path string) (*rsa.PrivateKey, error) {
+	if path == "" {
+		return nil, errors.New("rsa private key file is required")
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	block, _ := pem.Decode(data)
+	if block == nil {
+		return nil, errors.New("rsa private key file has no PEM block")
+	}
+	if key, err := x509.ParsePKCS1PrivateKey(block.Bytes); err == nil {
+		return key, nil
+	}
+	parsed, err := x509.ParsePKCS8PrivateKey(block.Bytes)
+	if err != nil {
+		return nil, err
+	}
+	key, ok := parsed.(*rsa.PrivateKey)
+	if !ok {
+		return nil, errors.New("private key is not an RSA private key")
+	}
+	return key, nil
+}
+
+func PublicJWKFromKey(key *rsa.PrivateKey) JWK {
+	publicKey := key.PublicKey
+	return JWK{
+		KeyType:   "RSA",
+		Use:       "sig",
+		KeyID:     RSAKeyID(&publicKey),
+		Algorithm: "RS256",
+		Modulus:   base64.RawURLEncoding.EncodeToString(publicKey.N.Bytes()),
+		Exponent:  base64.RawURLEncoding.EncodeToString(big.NewInt(int64(publicKey.E)).Bytes()),
+	}
+}
+
+func RSAKeyID(publicKey *rsa.PublicKey) string {
+	hash := sha256.Sum256(publicKey.N.Bytes())
+	return base64.RawURLEncoding.EncodeToString(hash[:8])
+}

server/internal/auth/random.go

@@ -0,0 +1,14 @@
+package auth
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+)
+
+func randomID() string {
+	var b [16]byte
+	if _, err := rand.Read(b[:]); err != nil {
+		return ""
+	}
+	return hex.EncodeToString(b[:])
+}