Introduce (*Parser).ParseUnverified

This is not something users of this library would commonly use but I'm
hitting a case where I still want to transmit the values contained
inside of the token trough the system, after it's been verified by the
frontend.

In that case it would be easier just to transmit the token around and be
able to parse the values within, without having to verify the signature.
The backend services also don't have access to the user secrets to
validate the signature.
This commit is contained in:
zimbatm 2016-07-21 17:37:13 +01:00
parent 24c63f5652
commit bf316c4813
1 changed files with 62 additions and 48 deletions

110
parser.go
View File

@ -21,55 +21,9 @@ func (p *Parser) Parse(tokenString string, keyFunc Keyfunc) (*Token, error) {
}
func (p *Parser) ParseWithClaims(tokenString string, claims Claims, keyFunc Keyfunc) (*Token, error) {
parts := strings.Split(tokenString, ".")
if len(parts) != 3 {
return nil, NewValidationError("token contains an invalid number of segments", ValidationErrorMalformed)
}
var err error
token := &Token{Raw: tokenString}
// parse Header
var headerBytes []byte
if headerBytes, err = DecodeSegment(parts[0]); err != nil {
if strings.HasPrefix(strings.ToLower(tokenString), "bearer ") {
return token, NewValidationError("tokenstring should not contain 'bearer '", ValidationErrorMalformed)
}
return token, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
}
if err = json.Unmarshal(headerBytes, &token.Header); err != nil {
return token, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
}
// parse Claims
var claimBytes []byte
token.Claims = claims
if claimBytes, err = DecodeSegment(parts[1]); err != nil {
return token, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
}
dec := json.NewDecoder(bytes.NewBuffer(claimBytes))
if p.UseJSONNumber {
dec.UseNumber()
}
// JSON Decode. Special case for map type to avoid weird pointer behavior
if c, ok := token.Claims.(MapClaims); ok {
err = dec.Decode(&c)
} else {
err = dec.Decode(&claims)
}
// Handle decode error
token, parts, err := p.ParseUnverified(tokenString, claims)
if err != nil {
return token, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
}
// Lookup signature method
if method, ok := token.Header["alg"].(string); ok {
if token.Method = GetSigningMethod(method); token.Method == nil {
return token, NewValidationError("signing method (alg) is unavailable.", ValidationErrorUnverifiable)
}
} else {
return token, NewValidationError("signing method (alg) is unspecified.", ValidationErrorUnverifiable)
return token, err
}
// Verify signing method is in the required set
@ -129,3 +83,63 @@ func (p *Parser) ParseWithClaims(tokenString string, claims Claims, keyFunc Keyf
return token, vErr
}
// WARNING: Don't use this method unless you know what you're doing
//
// This method parses the token but doesn't validate the signature. It's only
// ever useful in cases where you know the signature is valid (because it has
// been checked previously in the stack) and you want to extract values from
// it.
func (p *Parser) ParseUnverified(tokenString string, claims Claims) (token *Token, parts []string, err error) {
parts = strings.Split(tokenString, ".")
if len(parts) != 3 {
return nil, parts, NewValidationError("token contains an invalid number of segments", ValidationErrorMalformed)
}
token = &Token{Raw: tokenString}
// parse Header
var headerBytes []byte
if headerBytes, err = DecodeSegment(parts[0]); err != nil {
if strings.HasPrefix(strings.ToLower(tokenString), "bearer ") {
return token, parts, NewValidationError("tokenstring should not contain 'bearer '", ValidationErrorMalformed)
}
return token, parts, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
}
if err = json.Unmarshal(headerBytes, &token.Header); err != nil {
return token, parts, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
}
// parse Claims
var claimBytes []byte
token.Claims = claims
if claimBytes, err = DecodeSegment(parts[1]); err != nil {
return token, parts, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
}
dec := json.NewDecoder(bytes.NewBuffer(claimBytes))
if p.UseJSONNumber {
dec.UseNumber()
}
// JSON Decode. Special case for map type to avoid weird pointer behavior
if c, ok := token.Claims.(MapClaims); ok {
err = dec.Decode(&c)
} else {
err = dec.Decode(&claims)
}
// Handle decode error
if err != nil {
return token, parts, &ValidationError{Inner: err, Errors: ValidationErrorMalformed}
}
// Lookup signature method
if method, ok := token.Header["alg"].(string); ok {
if token.Method = GetSigningMethod(method); token.Method == nil {
return token, parts, NewValidationError("signing method (alg) is unavailable.", ValidationErrorUnverifiable)
}
} else {
return token, parts, NewValidationError("signing method (alg) is unspecified.", ValidationErrorUnverifiable)
}
return token, parts, nil
}