Verify functions now return errors instead of bool

Author: oxisto

map_claims.go

@@ -2,6 +2,7 @@ package jwt
 
 import (
 	"encoding/json"
+	"fmt"
 )
 
 // MapClaims is a claims type that uses the map[string]interface{} for JSON decoding.
@@ -60,7 +61,7 @@ func (m MapClaims) parseNumericDate(key string) (*NumericDate, error) {
 		return newNumericDateFromSeconds(v), nil
 	}
 
-	return nil, ErrInvalidType
+	return nil, newError(fmt.Sprintf("%s is invalid", key), ErrInvalidType)
 }
 
 // parseClaimsString tries to parse a key in the map claims type as a
@@ -76,7 +77,7 @@ func (m MapClaims) parseClaimsString(key string) (ClaimStrings, error) {
 		for _, a := range v {
 			vs, ok := a.(string)
 			if !ok {
-				return nil, ErrInvalidType
+				return nil, newError(fmt.Sprintf("%s is invalid", key), ErrInvalidType)
 			}
 			cs = append(cs, vs)
 		}
@@ -101,7 +102,7 @@ func (m MapClaims) parseString(key string) (string, error) {
 
 	iss, ok = raw.(string)
 	if !ok {
-		return "", ErrInvalidType
+		return "", newError(fmt.Sprintf("%s is invalid", key), ErrInvalidType)
 	}
 
 	return iss, nil

none.go

@@ -1,7 +1,5 @@
 package jwt
 
-import "fmt"
-
 // SigningMethodNone implements the none signing method.  This is required by the spec
 // but you probably should never use it.
 var SigningMethodNone *signingMethodNone
@@ -15,7 +13,7 @@ type unsafeNoneMagicConstant string
 
 func init() {
 	SigningMethodNone = &signingMethodNone{}
-	NoneSignatureTypeDisallowedError = fmt.Errorf("%w: 'none' signature type is not allowed", ErrTokenUnverifiable)
+	NoneSignatureTypeDisallowedError = newError("'none' signature type is not allowed", ErrTokenUnverifiable)
 
 	RegisterSigningMethod(SigningMethodNone.Alg(), func() SigningMethod {
 		return SigningMethodNone
@@ -35,7 +33,7 @@ func (m *signingMethodNone) Verify(signingString, signature string, key interfac
 	}
 	// If signing method is none, signature must be an empty string
 	if signature != "" {
-		return fmt.Errorf("%w: 'none' signing method with non-empty signature", ErrTokenUnverifiable)
+		return newError("'none' signing method with non-empty signature", ErrTokenUnverifiable)
 	}
 
 	// Accept 'none' signing method.

parser_test.go

@@ -334,7 +334,6 @@ func TestParser_Parse(t *testing.T) {
 
 			// Parse the token
 			var token *jwt.Token
-			//var ve *jwt.ValidationError
 			var err error
 			var parser = data.parser
 			if parser == nil {

validator.go

@@ -2,9 +2,32 @@ package jwt
 
 import (
 	"crypto/subtle"
+	"fmt"
 	"time"
 )
 
+// ClaimsValidator is an interface that can be implemented by custom claims who
+// wish to execute any additional claims validation based on
+// application-specific logic. The Validate function is then executed in
+// addition to the regular claims validation and any error returned is appended
+// to the final validation result.
+//
+//	type MyCustomClaims struct {
+//	    Foo string `json:"foo"`
+//	    jwt.RegisteredClaims
+//	}
+//
+//	func (m MyCustomClaims) Validate() error {
+//	    if m.Foo != "bar" {
+//	        return errors.New("must be foobar")
+//	    }
+//	    return nil
+//	}
+type ClaimsValidator interface {
+	Claims
+	Validate() error
+}
+
 // validator is the core of the new Validation API. It is automatically used by
 // a [Parser] during parsing and can be modified with various parser options.
 //
@@ -46,11 +69,12 @@ func newValidator(opts ...ParserOption) *validator {
 }
 
 // Validate validates the given claims. It will also perform any custom
-// validation if claims implements the CustomValidator interface.
+// validation if claims implements the [ClaimsValidator] interface.
 func (v *validator) Validate(claims Claims) error {
 	var (
 		now  time.Time
-		errs []error = make([]error, 0)
+		errs []error = make([]error, 0, 6)
+		err  error
 	)
 
 	// Check, if we have a time func
@@ -61,42 +85,48 @@ func (v *validator) Validate(claims Claims) error {
 	}
 
 	// We always need to check the expiration time, but usage of the claim
-	// itself is OPTIONAL
-	if !v.VerifyExpiresAt(claims, now, false) {
-		errs = append(errs, ErrTokenExpired)
+	// itself is OPTIONAL.
+	if err = v.verifyExpiresAt(claims, now, false); err != nil {
+		errs = append(errs, err)
 	}
 
 	// We always need to check not-before, but usage of the claim itself is
-	// OPTIONAL
-	if !v.VerifyNotBefore(claims, now, false) {
-		errs = append(errs, ErrTokenNotValidYet)
+	// OPTIONAL.
+	if err = v.verifyNotBefore(claims, now, false); err != nil {
+		errs = append(errs, err)
 	}
 
 	// Check issued-at if the option is enabled
-	if v.verifyIat && !v.VerifyIssuedAt(claims, now, false) {
-		errs = append(errs, ErrTokenUsedBeforeIssued)
+	if v.verifyIat {
+		if err = v.verifyIssuedAt(claims, now, false); err != nil {
+			errs = append(errs, err)
+		}
 	}
 
 	// If we have an expected audience, we also require the audience claim
-	if v.expectedAud != "" && !v.VerifyAudience(claims, v.expectedAud, true) {
-		errs = append(errs, ErrTokenInvalidAudience)
+	if v.expectedAud != "" {
+		if err = v.verifyAudience(claims, v.expectedAud, true); err != nil {
+			errs = append(errs, err)
+		}
 	}
 
 	// If we have an expected issuer, we also require the issuer claim
-	if v.expectedIss != "" && !v.VerifyIssuer(claims, v.expectedIss, true) {
-		errs = append(errs, ErrTokenInvalidIssuer)
+	if v.expectedIss != "" {
+		if err = v.verifyIssuer(claims, v.expectedIss, true); err != nil {
+			errs = append(errs, err)
+		}
 	}
 
 	// If we have an expected subject, we also require the subject claim
-	if v.expectedSub != "" && !v.VerifySubject(claims, v.expectedSub, true) {
-		errs = append(errs, ErrTokenInvalidSubject)
+	if v.expectedSub != "" {
+		if err = v.verifySubject(claims, v.expectedSub, true); err != nil {
+			errs = append(errs, ErrTokenInvalidSubject)
+		}
 	}
 
 	// Finally, we want to give the claim itself some possibility to do some
 	// additional custom validation based on a custom Validate function.
-	cvt, ok := claims.(interface {
-		Validate() error
-	})
+	cvt, ok := claims.(ClaimsValidator)
 	if ok {
 		if err := cvt.Validate(); err != nil {
 			errs = append(errs, err)
@@ -110,84 +140,84 @@ func (v *validator) Validate(claims Claims) error {
 	return joinErrors(errs)
 }
 
-// VerifyExpiresAt compares the exp claim in claims against cmp. This function
-// will return true if cmp < exp. Additional leeway is taken into account.
+// verifyExpiresAt compares the exp claim in claims against cmp. This function
+// will succeed if cmp < exp. Additional leeway is taken into account.
 //
-// If exp is not set, it will return true if the claim is not required,
-// otherwise false will be returned.
+// If exp is not set, it will succeed if the claim is not required,
+// otherwise ErrTokenRequiredClaimMissing will be returned.
 //
 // Additionally, if any error occurs while retrieving the claim, e.g., when its
-// the wrong type, false will be returned.
-func (v *validator) VerifyExpiresAt(claims Claims, cmp time.Time, required bool) bool {
+// the wrong type, an ErrTokenUnverifiable error will be returned.
+func (v *validator) verifyExpiresAt(claims Claims, cmp time.Time, required bool) error {
 	exp, err := claims.GetExpirationTime()
 	if err != nil {
-		return false
+		return err
 	}
 
-	if exp != nil {
-		return cmp.Before((exp.Time).Add(+v.leeway))
-	} else {
-		return !required
+	if exp == nil {
+		return errorIfRequired(required, "exp")
 	}
+
+	return errorIfFalse(cmp.Before((exp.Time).Add(+v.leeway)), ErrTokenExpired)
 }
 
-// VerifyIssuedAt compares the iat claim in claims against cmp. This function
-// will return true if cmp >= iat. Additional leeway is taken into account.
+// verifyIssuedAt compares the iat claim in claims against cmp. This function
+// will succeed if cmp >= iat. Additional leeway is taken into account.
 //
-// If iat is not set, it will return true if the claim is not required,
-// otherwise false will be returned.
+// If iat is not set, it will succeed if the claim is not required,
+// otherwise ErrTokenRequiredClaimMissing will be returned.
 //
 // Additionally, if any error occurs while retrieving the claim, e.g., when its
-// the wrong type, false will be returned.
-func (v *validator) VerifyIssuedAt(claims Claims, cmp time.Time, required bool) bool {
+// the wrong type, an ErrTokenUnverifiable error will be returned.
+func (v *validator) verifyIssuedAt(claims Claims, cmp time.Time, required bool) error {
 	iat, err := claims.GetIssuedAt()
 	if err != nil {
-		return false
+		return err
 	}
 
-	if iat != nil {
-		return !cmp.Before(iat.Add(-v.leeway))
-	} else {
-		return !required
+	if iat == nil {
+		return errorIfRequired(required, "iat")
 	}
+
+	return errorIfFalse(!cmp.Before(iat.Add(-v.leeway)), ErrTokenUsedBeforeIssued)
 }
 
-// VerifyNotBefore compares the nbf claim in claims against cmp. This function
+// verifyNotBefore compares the nbf claim in claims against cmp. This function
 // will return true if cmp >= nbf. Additional leeway is taken into account.
 //
-// If nbf is not set, it will return true if the claim is not required,
-// otherwise false will be returned.
+// If nbf is not set, it will succeed if the claim is not required,
+// otherwise ErrTokenRequiredClaimMissing will be returned.
 //
 // Additionally, if any error occurs while retrieving the claim, e.g., when its
-// the wrong type, false will be returned.
-func (v *validator) VerifyNotBefore(claims Claims, cmp time.Time, required bool) bool {
+// the wrong type, an ErrTokenUnverifiable error will be returned.
+func (v *validator) verifyNotBefore(claims Claims, cmp time.Time, required bool) error {
 	nbf, err := claims.GetNotBefore()
 	if err != nil {
-		return false
+		return err
 	}
 
-	if nbf != nil {
-		return !cmp.Before(nbf.Add(-v.leeway))
-	} else {
-		return !required
+	if nbf == nil {
+		return errorIfRequired(required, "nbf")
 	}
+
+	return errorIfFalse(!cmp.Before(nbf.Add(-v.leeway)), ErrTokenNotValidYet)
 }
 
-// VerifyAudience compares the aud claim against cmp.
+// verifyAudience compares the aud claim against cmp.
 //
-// If aud is not set or an empty list, it will return true if the claim is not
-// required, otherwise false will be returned.
+// If aud is not set or an empty list, it will succeed if the claim is not required,
+// otherwise ErrTokenRequiredClaimMissing will be returned.
 //
 // Additionally, if any error occurs while retrieving the claim, e.g., when its
-// the wrong type, false will be returned.
-func (v *validator) VerifyAudience(claims Claims, cmp string, required bool) bool {
+// the wrong type, an ErrTokenUnverifiable error will be returned.
+func (v *validator) verifyAudience(claims Claims, cmp string, required bool) error {
 	aud, err := claims.GetAudience()
 	if err != nil {
-		return false
+		return err
 	}
 
 	if len(aud) == 0 {
-		return !required
+		return errorIfRequired(required, "aud")
 	}
 
 	// use a var here to keep constant time compare when looping over a number of claims
@@ -203,48 +233,68 @@ func (v *validator) VerifyAudience(claims Claims, cmp string, required bool) boo
 
 	// case where "" is sent in one or many aud claims
 	if stringClaims == "" {
-		return !required
+		return errorIfRequired(required, "aud")
 	}
 
-	return result
+	return errorIfFalse(result, ErrTokenInvalidAudience)
 }
 
-// VerifyIssuer compares the iss claim in claims against cmp.
+// verifyIssuer compares the iss claim in claims against cmp.
 //
-// If iss is not set, it will return true if the claim is not required,
-// otherwise false will be returned.
+// If iss is not set, it will succeed if the claim is not required,
+// otherwise ErrTokenRequiredClaimMissing will be returned.
 //
 // Additionally, if any error occurs while retrieving the claim, e.g., when its
-// the wrong type, false will be returned.
-func (v *validator) VerifyIssuer(claims Claims, cmp string, required bool) bool {
+// the wrong type, an ErrTokenUnverifiable error will be returned.
+func (v *validator) verifyIssuer(claims Claims, cmp string, required bool) error {
 	iss, err := claims.GetIssuer()
 	if err != nil {
-		return false
+		return err
 	}
 
 	if iss == "" {
-		return !required
+		return errorIfRequired(required, "iss")
 	}
 
-	return iss == cmp
+	return errorIfFalse(iss == cmp, ErrTokenInvalidIssuer)
 }
 
-// VerifySubject compares the sub claim against cmp.
+// verifySubject compares the sub claim against cmp.
 //
-// If sub is not set, it will return true if the claim is not required,
-// otherwise false will be returned.
+// If sub is not set, it will succeed if the claim is not required,
+// otherwise ErrTokenRequiredClaimMissing will be returned.
 //
 // Additionally, if any error occurs while retrieving the claim, e.g., when its
-// the wrong type, false will be returned.
-func (v *validator) VerifySubject(claims Claims, cmp string, required bool) bool {
+// the wrong type, an ErrTokenUnverifiable error will be returned.
+func (v *validator) verifySubject(claims Claims, cmp string, required bool) error {
 	sub, err := claims.GetSubject()
 	if err != nil {
-		return false
+		return err
 	}
 
 	if sub == "" {
-		return !required
+		return errorIfRequired(required, "sub")
 	}
 
-	return sub == cmp
+	return errorIfFalse(sub == cmp, ErrTokenInvalidIssuer)
+}
+
+// errorIfFalse returns the error specified in err, if the value is true.
+// Otherwise, nil is returned.
+func errorIfFalse(value bool, err error) error {
+	if value {
+		return nil
+	} else {
+		return err
+	}
+}
+
+// errorIfRequired returns an ErrTokenRequiredClaimMissing error if required is
+// true. Otherwise, nil is returned.
+func errorIfRequired(required bool, claim string) error {
+	if required {
+		return newError(fmt.Sprintf("%s claim is required", claim), ErrTokenRequiredClaimMissing)
+	} else {
+		return nil
+	}
 }