feat: support OpenID Connect's response_mode=form_post

This patch adds support for the `response_mode` parameter as defined in [OAuth 2.0 Form Post Response Mode](https://openid.net/specs/oauth-v2-form-post-response-mode-1_0.html). Additionally, values `fragment` and `query` are supported as defined in [OAuth 2.0 Multiple Response Type Encoding Practices](https://openid.net/specs/oauth-v2-multiple-response-types-1_0.html).

Closes #1621

client/client.go

@@ -278,6 +278,15 @@ func (c *Client) GetResponseTypes() fosite.Arguments {
  return fosite.Arguments(c.ResponseTypes)
 }
 
+func (c *Client) GetResponseModes() []fosite.ResponseModeType {
+ return []fosite.ResponseModeType{
+ fosite.ResponseModeDefault,
+ fosite.ResponseModeFormPost,
+ fosite.ResponseModeQuery,
+ fosite.ResponseModeFragment,
+ }
+}
+
 func (c *Client) GetOwner() string {
  return c.Owner
 }

go.mod

@@ -2,6 +2,10 @@ module github.com/ory/hydra
 
 go 1.15
 
+//replace github.com/ory/fosite => ../fosite
+
+replace github.com/ory/fosite => github.com/ory/fosite v0.35.2-0.20201109171311-3731efd11b93
+
 require (
  github.com/dgrijalva/jwt-go v3.2.0+incompatible
  github.com/go-bindata/go-bindata v3.1.1+incompatible
@@ -37,7 +41,7 @@ require (
  github.com/ory/graceful v0.1.1
  github.com/ory/herodot v0.9.1
  github.com/ory/viper v1.7.5
- github.com/ory/x v0.0.153
+ github.com/ory/x v0.0.163
  github.com/pborman/uuid v1.2.0
  github.com/phayes/freeport v0.0.0-20171002181615-b8543db493a5
  github.com/pkg/errors v0.9.1