idiomatic project structure

internal/security/jwt_claims.go

@@ -0,0 +1,123 @@
+package security
+
+import (
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/google/uuid"
+	"go-nkode/config"
+	"log"
+	"os"
+	"time"
+)
+
+type AuthenticationTokens struct {
+	AccessToken  string `json:"access_token"`
+	RefreshToken string `json:"refresh_token"`
+}
+
+type ResetNKodeClaims struct {
+	Reset bool `json:"reset"`
+	jwt.RegisteredClaims
+}
+
+const (
+	accessTokenExp     = 5 * time.Minute
+	refreshTokenExp    = 30 * 24 * time.Hour
+	resetNKodeTokenExp = 5 * time.Minute
+)
+
+var secret = getJwtSecret()
+
+func getJwtSecret() []byte {
+	jwtSecret := os.Getenv("JWT_SECRET")
+	if jwtSecret == "" {
+		log.Fatal("No JWT_SECRET found")
+	}
+
+	jwtBytes, err := ParseHexString(jwtSecret)
+	if err != nil {
+		log.Fatalf("error parsing jwt secret %v", err)
+	}
+	return jwtBytes
+}
+
+func NewAuthenticationTokens(username string, customerId uuid.UUID) (AuthenticationTokens, error) {
+	accessClaims := NewAccessClaim(username, customerId)
+
+	refreshClaims := jwt.RegisteredClaims{
+		Subject:   username,
+		Issuer:    customerId.String(),
+		ExpiresAt: jwt.NewNumericDate(time.Now().Add(refreshTokenExp)),
+	}
+
+	accessJwt, err := EncodeAndSignClaims(accessClaims)
+	if err != nil {
+		return AuthenticationTokens{}, err
+	}
+	refreshJwt, err := EncodeAndSignClaims(refreshClaims)
+
+	if err != nil {
+		return AuthenticationTokens{}, err
+	}
+	return AuthenticationTokens{
+		AccessToken:  accessJwt,
+		RefreshToken: refreshJwt,
+	}, nil
+}
+
+func NewAccessClaim(username string, customerId uuid.UUID) jwt.RegisteredClaims {
+	return jwt.RegisteredClaims{
+		Subject:   username,
+		Issuer:    customerId.String(),
+		ExpiresAt: jwt.NewNumericDate(time.Now().Add(accessTokenExp)),
+	}
+}
+
+func EncodeAndSignClaims(claims jwt.Claims) (string, error) {
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString(secret)
+}
+
+func ParseRegisteredClaimToken(token string) (*jwt.RegisteredClaims, error) {
+	return parseJwt[*jwt.RegisteredClaims](token, &jwt.RegisteredClaims{})
+}
+
+func ParseRestNKodeToken(resetNKodeToken string) (*ResetNKodeClaims, error) {
+	return parseJwt[*ResetNKodeClaims](resetNKodeToken, &ResetNKodeClaims{})
+}
+
+func parseJwt[T *ResetNKodeClaims | *jwt.RegisteredClaims](tokenStr string, claim jwt.Claims) (T, error) {
+	token, err := jwt.ParseWithClaims(tokenStr, claim, func(token *jwt.Token) (interface{}, error) {
+		return secret, nil
+	})
+	if err != nil {
+		log.Printf("error parsing refresh token: %v", err)
+		return nil, config.ErrInvalidJwt
+	}
+	claims, ok := token.Claims.(T)
+	if !ok {
+		return nil, config.ErrInvalidJwt
+	}
+	return claims, nil
+}
+
+func ClaimExpired(claims jwt.RegisteredClaims) error {
+	if claims.ExpiresAt == nil {
+		return config.ErrClaimExpOrNil
+	}
+	if claims.ExpiresAt.Time.After(time.Now()) {
+		return nil
+	}
+	return config.ErrClaimExpOrNil
+}
+
+func ResetNKodeToken(userEmail string, customerId uuid.UUID) (string, error) {
+	resetClaims := ResetNKodeClaims{
+		true,
+		jwt.RegisteredClaims{
+			Subject:   userEmail,
+			Issuer:    customerId.String(),
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(resetNKodeTokenExp)),
+		},
+	}
+	return EncodeAndSignClaims(resetClaims)
+}