// MarshalJSON serializes the given key to its JSON representation.
func (k JsonWebKey) MarshalJSON() ([]byte, error) {
var raw *rawJsonWebKey
var err error
switch key := k.Key.(type) {
case *ecdsa.PublicKey:
raw, err = fromEcPublicKey(key)
case *rsa.PublicKey:
raw = fromRsaPublicKey(key)
case *ecdsa.PrivateKey:
raw, err = fromEcPrivateKey(key)
case *rsa.PrivateKey:
raw, err = fromRsaPrivateKey(key)
case []byte:
raw, err = fromSymmetricKey(key)
default:
return nil, fmt.Errorf("square/go-jose: unknown key type '%s'", reflect.TypeOf(key))
}
if err != nil {
return nil, err
}
raw.Kid = k.KeyID
raw.Alg = k.Algorithm
raw.Use = k.Use
for _, cert := range k.Certificates {
raw.X5c = append(raw.X5c, base64.StdEncoding.EncodeToString(cert.Raw))
}
return json.Marshal(raw)
}
// Helper function to serialize known-good objects.
// Precondition: value is not a nil pointer.
func mustSerializeJSON(value interface{}) []byte {
out, err := json.Marshal(value)
if err != nil {
panic(err)
}
// We never want to serialize the top-level value "null," since it's not a
// valid JOSE message. But if a caller passes in a nil pointer to this method,
// MarshalJSON will happily serialize it as the top-level value "null". If
// that value is then embedded in another operation, for instance by being
// base64-encoded and fed as input to a signing algorithm
// (https://github.com/square/go-jose/issues/22), the result will be
// incorrect. Because this method is intended for known-good objects, and a nil
// pointer is not a known-good object, we are free to panic in this case.
// Note: It's not possible to directly check whether the data pointed at by an
// interface is a nil pointer, so we do this hacky workaround.
// https://groups.google.com/forum/#!topic/golang-nuts/wnH302gBa4I
if string(out) == "null" {
panic("Tried to serialize a nil pointer.")
}
return out
}
func (b *byteBuffer) MarshalJSON() ([]byte, error) {
return json.Marshal(b.base64())
}