feat: 0.0.1

internal/auth/paseto_maker.go

@@ -0,0 +1,97 @@
+package auth
+
+import (
+	"strings"
+	"time"
+
+	"aidanwoods.dev/go-paseto"
+	"github.com/FernandoJVideira/simple_bank/internal/config"
+	"github.com/google/uuid"
+)
+
+type PasetoMaker struct {
+	config       config.Config
+	symmetricKey paseto.V4SymmetricKey
+	implicit     []byte
+}
+
+func NewPasetoMaker(config config.Config) (Maker, error) {
+	maker := &PasetoMaker{
+		config:       config,
+		symmetricKey: paseto.NewV4SymmetricKey(),
+		implicit:     []byte("implicit"),
+	}
+	return maker, nil
+}
+
+func (maker *PasetoMaker) CreateToken(username string, role string, duration time.Duration) (string, *Payload, error) {
+	payload, err := NewPayload(username, role, duration)
+	if err != nil {
+		return "", nil, err
+	}
+
+	token := paseto.NewToken()
+	token.SetIssuedAt(payload.IssuedAt)
+	token.SetExpiration(payload.ExpiredAt)
+	token.SetString("role", payload.Role)
+	token.SetAudience(maker.config.TokenAUD)
+	token.SetIssuer(maker.config.TokenISS)
+	token.SetSubject(payload.Username)
+	token.SetJti(payload.ID.String())
+
+	signedToken := token.V4Encrypt(maker.symmetricKey, maker.implicit)
+
+	return signedToken, payload, nil
+}
+
+func (maker *PasetoMaker) VerifyToken(token string) (*Payload, error) {
+	parser := paseto.NewParser()
+	parser.AddRule(paseto.NotExpired())
+
+	parsedToken, err := parser.ParseV4Local(maker.symmetricKey, token, maker.implicit)
+	if err != nil {
+		if strings.Contains(err.Error(), "token has expired") {
+			return nil, ErrExpiredToken
+		}
+		return nil, ErrInvalidToken
+	}
+
+	payload, err := parseClaims(parsedToken)
+	if err != nil {
+		return nil, err
+	}
+
+	return payload, nil
+}
+
+func parseClaims(t *paseto.Token) (*Payload, error) {
+	id, err := t.GetJti()
+	if err != nil {
+		return nil, ErrInvalidToken
+	}
+	username, err := t.GetSubject()
+	if err != nil {
+		return nil, ErrInvalidToken
+	}
+	role, err := t.GetString("role")
+	if err != nil {
+		return nil, ErrInvalidToken
+	}
+	issuedAt, err := t.GetIssuedAt()
+	if err != nil {
+		return nil, ErrInvalidToken
+	}
+	expiredAt, err := t.GetExpiration()
+	if err != nil {
+		return nil, ErrInvalidToken
+	}
+
+	payload := &Payload{
+		ID:        uuid.MustParse(id),
+		Username:  username,
+		Role:      role,
+		IssuedAt:  issuedAt,
+		ExpiredAt: expiredAt,
+	}
+	return payload, nil
+}