fix: broken JSON round-tripping for custom claims

Adding custom claims with numerical types (think JavaScript Number) previously did not
round-trip through Hydra correctly. For example, passing UNIX timestamps in custom claims
would end up as floating points in exponential notation in the final token. That, in turn,
confused or broke downstream consumers of the token, including Kratos.

Ref go-jose/go-jose#144

consent/strategy_oauth_test.go

@@ -289,6 +289,7 @@ func TestStrategyLoginConsentNext(t *testing.T) {
 
 		subject := "aeneas-rekkas"
 		c := createDefaultClient(t)
+		now := 1723546027 // Unix timestamps must round-trip through Hydra without converting to floats or similar
 		testhelpers.NewLoginConsentUI(t, reg.Config(),
 			acceptLoginHandler(t, subject, &hydra.AcceptOAuth2LoginRequest{
 				Remember: pointerx.Bool(true),
@@ -297,8 +298,14 @@ func TestStrategyLoginConsentNext(t *testing.T) {
 				Remember:   pointerx.Bool(true),
 				GrantScope: []string{"openid"},
 				Session: &hydra.AcceptOAuth2ConsentRequestSession{
-					AccessToken: map[string]interface{}{"foo": "bar"},
-					IdToken:     map[string]interface{}{"bar": "baz"},
+					AccessToken: map[string]interface{}{
+						"foo": "bar",
+						"ts1": now,
+					},
+					IdToken: map[string]interface{}{
+						"bar": "baz",
+						"ts2": now,
+					},
 				},
 			}))
 
@@ -314,12 +321,14 @@ func TestStrategyLoginConsentNext(t *testing.T) {
 			require.NoError(t, err)
 
 			claims := testhelpers.IntrospectToken(t, conf, token.AccessToken, adminTS)
-			assert.Equal(t, "bar", claims.Get("ext.foo").String(), "%s", claims.Raw)
+			assert.Equalf(t, `"bar"`, claims.Get("ext.foo").Raw, "%s", claims.Raw)      // Raw rather than .Int() or .Value() to verify the exact JSON payload
+			assert.Equalf(t, "1723546027", claims.Get("ext.ts1").Raw, "%s", claims.Raw) // must round-trip as integer
 
 			idClaims := testhelpers.DecodeIDToken(t, token)
-			assert.Equal(t, "baz", idClaims.Get("bar").String(), "%s", idClaims.Raw)
+			assert.Equalf(t, `"baz"`, idClaims.Get("bar").Raw, "%s", idClaims.Raw)      // Raw rather than .Int() or .Value() to verify the exact JSON payload
+			assert.Equalf(t, "1723546027", idClaims.Get("ts2").Raw, "%s", idClaims.Raw) // must round-trip as integer
 			sid = idClaims.Get("sid").String()
-			assert.NotNil(t, sid)
+			assert.NotEmpty(t, sid)
 		}
 
 		t.Run("perform first flow", run)
@@ -334,21 +343,28 @@ func TestStrategyLoginConsentNext(t *testing.T) {
 					assert.Empty(t, pointerx.StringR(res.Client.ClientSecret))
 					return hydra.AcceptOAuth2LoginRequest{
 						Subject: subject,
-						Context: map[string]interface{}{"foo": "bar"},
+						Context: map[string]interface{}{"xyz": "abc"},
 					}
 				}),
-				checkAndAcceptConsentHandler(t, adminClient, func(t *testing.T, res *hydra.OAuth2ConsentRequest, err error) hydra.AcceptOAuth2ConsentRequest {
+				checkAndAcceptConsentHandler(t, adminClient, func(t *testing.T, req *hydra.OAuth2ConsentRequest, err error) hydra.AcceptOAuth2ConsentRequest {
 					require.NoError(t, err)
-					assert.True(t, *res.Skip)
-					assert.Equal(t, sid, *res.LoginSessionId)
-					assert.Equal(t, subject, *res.Subject)
-					assert.Empty(t, pointerx.StringR(res.Client.ClientSecret))
+					assert.True(t, *req.Skip)
+					assert.Equal(t, sid, *req.LoginSessionId)
+					assert.Equal(t, subject, *req.Subject)
+					assert.Empty(t, pointerx.StringR(req.Client.ClientSecret))
+					assert.Equal(t, map[string]interface{}{"xyz": "abc"}, req.Context)
 					return hydra.AcceptOAuth2ConsentRequest{
 						Remember:   pointerx.Bool(true),
 						GrantScope: []string{"openid"},
 						Session: &hydra.AcceptOAuth2ConsentRequestSession{
-							AccessToken: map[string]interface{}{"foo": "bar"},
-							IdToken:     map[string]interface{}{"bar": "baz"},
+							AccessToken: map[string]interface{}{
+								"foo": "bar",
+								"ts1": now,
+							},
+							IdToken: map[string]interface{}{
+								"bar": "baz",
+								"ts2": now,
+							},
 						},
 					}
 				}))

oauth2/.snapshots/TestUnmarshalSession-v1.11.8.json

@@ -17,7 +17,8 @@
       "amr": [],
       "c_hash": "",
       "ext": {
-        "sid": "177e1f44-a1e9-415c-bfa3-8b62280b182d"
+        "sid": "177e1f44-a1e9-415c-bfa3-8b62280b182d",
+        "timestamp": 1723546027
       }
     },
     "headers": {

oauth2/.snapshots/TestUnmarshalSession-v1.11.9.json

@@ -17,7 +17,8 @@
       "amr": [],
       "c_hash": "",
       "ext": {
-        "sid": "177e1f44-a1e9-415c-bfa3-8b62280b182d"
+        "sid": "177e1f44-a1e9-415c-bfa3-8b62280b182d",
+        "timestamp": 1723546027
       }
     },
     "headers": {

oauth2/fixtures/v1.11.8-session.json

@@ -15,7 +15,8 @@
       "AuthenticationMethodsReferences": [],
       "CodeHash": "",
       "Extra": {
-        "sid": "177e1f44-a1e9-415c-bfa3-8b62280b182d"
+        "sid": "177e1f44-a1e9-415c-bfa3-8b62280b182d",
+        "timestamp": 1723546027
       }
     },
     "Headers": {

oauth2/fixtures/v1.11.9-session.json

@@ -15,7 +15,8 @@
       "amr": [],
       "c_hash": "",
       "ext": {
-        "sid": "177e1f44-a1e9-415c-bfa3-8b62280b182d"
+        "sid": "177e1f44-a1e9-415c-bfa3-8b62280b182d",
+        "timestamp": 1723546027
       }
     },
     "headers": {

oauth2/session.go

@@ -4,22 +4,21 @@
 package oauth2
 
 import (
+	"bytes"
 	"context"
-	"encoding/json"
 	"time"
 
+	jjson "github.com/go-jose/go-jose/v3/json"
+	"github.com/mohae/deepcopy"
 	"github.com/pkg/errors"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
 
-	"github.com/mohae/deepcopy"
-
 	"github.com/ory/fosite"
 	"github.com/ory/fosite/handler/openid"
 	"github.com/ory/fosite/token/jwt"
 	"github.com/ory/hydra/v2/driver/config"
 	"github.com/ory/hydra/v2/flow"
-
 	"github.com/ory/x/logrusx"
 	"github.com/ory/x/stringslice"
 )
@@ -60,33 +59,33 @@ func NewSessionWithCustomClaims(ctx context.Context, p *config.DefaultProvider,
 }
 
 func (s *Session) GetJWTClaims() jwt.JWTClaimsContainer {
-	//a slice of claims that are reserved and should not be overridden
-	var reservedClaims = []string{"iss", "sub", "aud", "exp", "nbf", "iat", "jti", "client_id", "scp", "ext"}
+	// a slice of claims that are reserved and should not be overridden
+	reservedClaims := []string{"iss", "sub", "aud", "exp", "nbf", "iat", "jti", "client_id", "scp", "ext"}
 
-	//remove any reserved claims from the custom claims
+	// remove any reserved claims from the custom claims
 	allowedClaimsFromConfigWithoutReserved := stringslice.Filter(s.AllowedTopLevelClaims, func(s string) bool {
 		return stringslice.Has(reservedClaims, s)
 	})
 
-	//our new extra map which will be added to the jwt
-	var topLevelExtraWithMirrorExt = map[string]interface{}{}
+	// our new extra map which will be added to the jwt
+	topLevelExtraWithMirrorExt := map[string]interface{}{}
 
-	//setting every allowed claim top level in jwt with respective value
+	// setting every allowed claim top level in jwt with respective value
 	for _, allowedClaim := range allowedClaimsFromConfigWithoutReserved {
 		if cl, ok := s.Extra[allowedClaim]; ok {
 			topLevelExtraWithMirrorExt[allowedClaim] = cl
 		}
 	}
 
-	//for every other claim that was already reserved and for mirroring, add original extra under "ext"
+	// for every other claim that was already reserved and for mirroring, add original extra under "ext"
 	if s.MirrorTopLevelClaims {
 		topLevelExtraWithMirrorExt["ext"] = s.Extra
 	}
 
 	claims := &jwt.JWTClaims{
 		Subject: s.Subject,
 		Issuer:  s.DefaultSession.Claims.Issuer,
-		//set our custom extra map as claims.Extra
+		// set our custom extra map as claims.Extra
 		Extra:     topLevelExtraWithMirrorExt,
 		ExpiresAt: s.GetExpiresAt(fosite.AccessToken),
 		IssuedAt:  time.Now(),
@@ -185,8 +184,11 @@ func (s *Session) UnmarshalJSON(original []byte) (err error) {
 		}
 	}
 
+	// https://github.com/go-jose/go-jose/issues/144
+	dec := jjson.NewDecoder(bytes.NewReader(transformed))
+	dec.SetNumberType(jjson.UnmarshalIntOrFloat)
 	type t Session
-	if err := json.Unmarshal(transformed, (*t)(s)); err != nil {
+	if err := dec.Decode((*t)(s)); err != nil {
 		return errors.WithStack(err)
 	}
 

oauth2/session_test.go

@@ -49,7 +49,8 @@ func TestUnmarshalSession(t *testing.T) {
 				AuthenticationMethodsReferences:     []string{},
 				CodeHash:                            "",
 				Extra: map[string]interface{}{
-					"sid": "177e1f44-a1e9-415c-bfa3-8b62280b182d",
+					"sid":       "177e1f44-a1e9-415c-bfa3-8b62280b182d",
+					"timestamp": 1723546027,
 				},
 			},
 			Headers: &jwt.Headers{Extra: map[string]interface{}{
@@ -85,7 +86,7 @@ func TestUnmarshalSession(t *testing.T) {
 		snapshotx.SnapshotTExcept(t, &actual, nil)
 	})
 
-	t.Run("v1.11.9", func(t *testing.T) {
+	t.Run("v1.11.9" /* and later versions */, func(t *testing.T) {
 		var actual Session
 		require.NoError(t, json.Unmarshal(v1119Session, &actual))
 		assertx.EqualAsJSON(t, expect, &actual)