first commit

internal/jwt/jwt.go

@@ -0,0 +1,59 @@
+package jwt
+
+import (
+	"errors"
+	"time"
+
+	"github.com/lestrrat-go/jwx/v3/jwa"
+	"github.com/lestrrat-go/jwx/v3/jwt"
+)
+
+type JWT struct {
+	secret         []byte
+	accessTokenTTL time.Duration
+}
+
+func New(secret string) *JWT {
+	return &JWT{
+		secret:         []byte(secret),
+		accessTokenTTL: 15 * time.Minute,
+	}
+}
+
+func (j *JWT) GenerateAccessToken(userID, email string) (string, error) {
+	tok, err := jwt.NewBuilder().
+		Subject(userID).
+		IssuedAt(time.Now()).
+		Expiration(time.Now().Add(j.accessTokenTTL)).
+		Claim("type", "access").
+		Claim("email", email).
+		Build()
+	if err != nil {
+		return "", err
+	}
+
+	signed, err := jwt.Sign(tok, jwt.WithKey(jwa.HS256(), j.secret))
+	if err != nil {
+		return "", err
+	}
+
+	return string(signed), nil
+}
+
+func (j *JWT) ValidateAccessToken(tokenStr string) (string, error) {
+	tok, err := jwt.Parse(
+		[]byte(tokenStr),
+		jwt.WithKey(jwa.HS256(), j.secret),
+		jwt.WithValidate(true),
+	)
+	if err != nil {
+		return "", err
+	}
+
+	subject, ok := tok.Subject()
+	if !ok {
+		return "", errors.New("token does not contain subject")
+	}
+
+	return subject, nil
+}