switch to maintained lib (#16532)

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Andrew Thornton <art27@cantab.net>

vendor/github.com/golang-jwt/jwt/errors.go

@@ -0,0 +1,59 @@
+package jwt
+
+import (
+	"errors"
+)
+
+// Error constants
+var (
+	ErrInvalidKey      = errors.New("key is invalid")
+	ErrInvalidKeyType  = errors.New("key is of invalid type")
+	ErrHashUnavailable = errors.New("the requested hash function is unavailable")
+)
+
+// The errors that might occur when parsing and validating a token
+const (
+	ValidationErrorMalformed        uint32 = 1 << iota // Token is malformed
+	ValidationErrorUnverifiable                        // Token could not be verified because of signing problems
+	ValidationErrorSignatureInvalid                    // Signature validation failed
+
+	// Standard Claim validation errors
+	ValidationErrorAudience      // AUD validation failed
+	ValidationErrorExpired       // EXP validation failed
+	ValidationErrorIssuedAt      // IAT validation failed
+	ValidationErrorIssuer        // ISS validation failed
+	ValidationErrorNotValidYet   // NBF validation failed
+	ValidationErrorId            // JTI validation failed
+	ValidationErrorClaimsInvalid // Generic claims validation error
+)
+
+// Helper for constructing a ValidationError with a string error message
+func NewValidationError(errorText string, errorFlags uint32) *ValidationError {
+	return &ValidationError{
+		text:   errorText,
+		Errors: errorFlags,
+	}
+}
+
+// The error from Parse if token is not valid
+type ValidationError struct {
+	Inner  error  // stores the error returned by external dependencies, i.e.: KeyFunc
+	Errors uint32 // bitfield.  see ValidationError... constants
+	text   string // errors that do not have a valid error just have text
+}
+
+// Validation error is an error type
+func (e ValidationError) Error() string {
+	if e.Inner != nil {
+		return e.Inner.Error()
+	} else if e.text != "" {
+		return e.text
+	} else {
+		return "token is invalid"
+	}
+}
+
+// No errors
+func (e *ValidationError) valid() bool {
+	return e.Errors == 0
+}