federated authentication better logging + tidying (#232)

* change trace logging in authenticator

* messing about

* lil changes

* go fmt

* error fix

* Fix broken test

internal/api/s2s/user/common.go

@@ -0,0 +1,59 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package user
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/gin-gonic/gin"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
+)
+
+// ActivityPubAcceptHeaders represents the Accept headers mentioned here:
+// https://www.w3.org/TR/activitypub/#retrieving-objects
+var ActivityPubAcceptHeaders = []string{
+	`application/activity+json`,
+	`application/ld+json; profile="https://www.w3.org/ns/activitystreams"`,
+}
+
+// populateContext transfers the signature verifier and signature from the gin context to the request context
+func populateContext(c *gin.Context) context.Context {
+	ctx := c.Request.Context()
+
+	verifier, signed := c.Get(string(util.APRequestingPublicKeyVerifier))
+	if signed {
+		ctx = context.WithValue(ctx, util.APRequestingPublicKeyVerifier, verifier)
+	}
+
+	signature, signed := c.Get(string(util.APRequestingPublicKeySignature))
+	if signed {
+		ctx = context.WithValue(ctx, util.APRequestingPublicKeySignature, signature)
+	}
+
+	return ctx
+}
+
+func negotiateFormat(c *gin.Context) (string, error) {
+	format := c.NegotiateFormat(ActivityPubAcceptHeaders...)
+	if format == "" {
+		return "", fmt.Errorf("no format can be offered for Accept headers %s", c.Request.Header.Get("Accept"))
+	}
+	return format, nil
+}

internal/api/s2s/user/followers.go

@@ -19,14 +19,12 @@
 package user
 
 import (
-	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
 	"github.com/sirupsen/logrus"
-	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 // FollowersGETHandler returns a collection of URIs for followers of the target user, formatted so that other AP servers can understand it.
@@ -42,25 +40,19 @@ func (m *Module) FollowersGETHandler(c *gin.Context) {
 		return
 	}
 
-	// make sure this actually an AP request
-	format := c.NegotiateFormat(ActivityPubAcceptHeaders...)
-	if format == "" {
-		c.JSON(http.StatusNotAcceptable, gin.H{"error": "could not negotiate format with given Accept header(s)"})
+	format, err := negotiateFormat(c)
+	if err != nil {
+		c.JSON(http.StatusNotAcceptable, gin.H{"error": fmt.Sprintf("could not negotiate format with given Accept header(s): %s", err)})
 		return
 	}
 	l.Tracef("negotiated format: %s", format)
 
-	// transfer the signature verifier from the gin context to the request context
-	ctx := c.Request.Context()
-	verifier, signed := c.Get(string(util.APRequestingPublicKeyVerifier))
-	if signed {
-		ctx = context.WithValue(ctx, util.APRequestingPublicKeyVerifier, verifier)
-	}
+	ctx := populateContext(c)
 
-	followers, err := m.processor.GetFediFollowers(ctx, requestedUsername, c.Request.URL) // GetFediUser handles auth as well
-	if err != nil {
-		l.Info(err.Error())
-		c.JSON(err.Code(), gin.H{"error": err.Safe()})
+	followers, errWithCode := m.processor.GetFediFollowers(ctx, requestedUsername, c.Request.URL)
+	if errWithCode != nil {
+		l.Info(errWithCode.Error())
+		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
 		return
 	}
 

internal/api/s2s/user/following.go

@@ -19,14 +19,12 @@
 package user
 
 import (
-	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
 	"github.com/sirupsen/logrus"
-	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 // FollowingGETHandler returns a collection of URIs for accounts that the target user follows, formatted so that other AP servers can understand it.
@@ -42,25 +40,19 @@ func (m *Module) FollowingGETHandler(c *gin.Context) {
 		return
 	}
 
-	// make sure this actually an AP request
-	format := c.NegotiateFormat(ActivityPubAcceptHeaders...)
-	if format == "" {
-		c.JSON(http.StatusNotAcceptable, gin.H{"error": "could not negotiate format with given Accept header(s)"})
+	format, err := negotiateFormat(c)
+	if err != nil {
+		c.JSON(http.StatusNotAcceptable, gin.H{"error": fmt.Sprintf("could not negotiate format with given Accept header(s): %s", err)})
 		return
 	}
 	l.Tracef("negotiated format: %s", format)
 
-	// transfer the signature verifier from the gin context to the request context
-	ctx := c.Request.Context()
-	verifier, signed := c.Get(string(util.APRequestingPublicKeyVerifier))
-	if signed {
-		ctx = context.WithValue(ctx, util.APRequestingPublicKeyVerifier, verifier)
-	}
+	ctx := populateContext(c)
 
-	following, err := m.processor.GetFediFollowing(ctx, requestedUsername, c.Request.URL) // handles auth as well
-	if err != nil {
-		l.Info(err.Error())
-		c.JSON(err.Code(), gin.H{"error": err.Safe()})
+	following, errWithCode := m.processor.GetFediFollowing(ctx, requestedUsername, c.Request.URL)
+	if errWithCode != nil {
+		l.Info(errWithCode.Error())
+		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
 		return
 	}
 

internal/api/s2s/user/inboxpost.go

@@ -19,13 +19,11 @@
 package user
 
 import (
-	"context"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
 	"github.com/sirupsen/logrus"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
-	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 // InboxPOSTHandler deals with incoming POST requests to an actor's inbox.
@@ -42,12 +40,7 @@ func (m *Module) InboxPOSTHandler(c *gin.Context) {
 		return
 	}
 
-	// transfer the signature verifier from the gin context to the request context
-	ctx := c.Request.Context()
-	verifier, signed := c.Get(string(util.APRequestingPublicKeyVerifier))
-	if signed {
-		ctx = context.WithValue(ctx, util.APRequestingPublicKeyVerifier, verifier)
-	}
+	ctx := populateContext(c)
 
 	posted, err := m.processor.InboxPost(ctx, c.Writer, c.Request)
 	if err != nil {

internal/api/s2s/user/publickeyget.go

@@ -1,14 +1,12 @@
 package user
 
 import (
-	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
 	"github.com/sirupsen/logrus"
-	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 // PublicKeyGETHandler should be served at eg https://example.org/users/:username/main-key.
@@ -28,25 +26,19 @@ func (m *Module) PublicKeyGETHandler(c *gin.Context) {
 		return
 	}
 
-	// make sure this actually an AP request
-	format := c.NegotiateFormat(ActivityPubAcceptHeaders...)
-	if format == "" {
-		c.JSON(http.StatusNotAcceptable, gin.H{"error": "could not negotiate format with given Accept header(s)"})
+	format, err := negotiateFormat(c)
+	if err != nil {
+		c.JSON(http.StatusNotAcceptable, gin.H{"error": fmt.Sprintf("could not negotiate format with given Accept header(s): %s", err)})
 		return
 	}
 	l.Tracef("negotiated format: %s", format)
 
-	// transfer the signature verifier from the gin context to the request context
-	ctx := c.Request.Context()
-	verifier, signed := c.Get(string(util.APRequestingPublicKeyVerifier))
-	if signed {
-		ctx = context.WithValue(ctx, util.APRequestingPublicKeyVerifier, verifier)
-	}
+	ctx := populateContext(c)
 
-	user, err := m.processor.GetFediUser(ctx, requestedUsername, c.Request.URL) // GetFediUser handles auth as well
-	if err != nil {
-		l.Info(err.Error())
-		c.JSON(err.Code(), gin.H{"error": err.Safe()})
+	user, errWithCode := m.processor.GetFediUser(ctx, requestedUsername, c.Request.URL)
+	if errWithCode != nil {
+		l.Info(errWithCode.Error())
+		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
 		return
 	}
 

internal/api/s2s/user/repliesget.go

@@ -1,7 +1,6 @@
 package user
 
 import (
-	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -9,7 +8,6 @@ import (
 
 	"github.com/gin-gonic/gin"
 	"github.com/sirupsen/logrus"
-	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 // StatusRepliesGETHandler swagger:operation GET /users/{username}/statuses/{status}/replies s2sRepliesGet
@@ -116,25 +114,19 @@ func (m *Module) StatusRepliesGETHandler(c *gin.Context) {
 		minID = minIDString
 	}
 
-	// make sure this actually an AP request
-	format := c.NegotiateFormat(ActivityPubAcceptHeaders...)
-	if format == "" {
-		c.JSON(http.StatusNotAcceptable, gin.H{"error": "could not negotiate format with given Accept header(s)"})
+	format, err := negotiateFormat(c)
+	if err != nil {
+		c.JSON(http.StatusNotAcceptable, gin.H{"error": fmt.Sprintf("could not negotiate format with given Accept header(s): %s", err)})
 		return
 	}
 	l.Tracef("negotiated format: %s", format)
 
-	// transfer the signature verifier from the gin context to the request context
-	ctx := c.Request.Context()
-	verifier, signed := c.Get(string(util.APRequestingPublicKeyVerifier))
-	if signed {
-		ctx = context.WithValue(ctx, util.APRequestingPublicKeyVerifier, verifier)
-	}
+	ctx := populateContext(c)
 
-	replies, err := m.processor.GetFediStatusReplies(ctx, requestedUsername, requestedStatusID, page, onlyOtherAccounts, minID, c.Request.URL)
-	if err != nil {
-		l.Info(err.Error())
-		c.JSON(err.Code(), gin.H{"error": err.Safe()})
+	replies, errWithCode := m.processor.GetFediStatusReplies(ctx, requestedUsername, requestedStatusID, page, onlyOtherAccounts, minID, c.Request.URL)
+	if errWithCode != nil {
+		l.Info(errWithCode.Error())
+		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
 		return
 	}
 

internal/api/s2s/user/statusget.go

@@ -1,14 +1,12 @@
 package user
 
 import (
-	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
 	"github.com/sirupsen/logrus"
-	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 // StatusGETHandler serves the target status as an activitystreams NOTE so that other AP servers can parse it.
@@ -30,25 +28,19 @@ func (m *Module) StatusGETHandler(c *gin.Context) {
 		return
 	}
 
-	// make sure this actually an AP request
-	format := c.NegotiateFormat(ActivityPubAcceptHeaders...)
-	if format == "" {
-		c.JSON(http.StatusNotAcceptable, gin.H{"error": "could not negotiate format with given Accept header(s)"})
+	format, err := negotiateFormat(c)
+	if err != nil {
+		c.JSON(http.StatusNotAcceptable, gin.H{"error": fmt.Sprintf("could not negotiate format with given Accept header(s): %s", err)})
 		return
 	}
 	l.Tracef("negotiated format: %s", format)
 
-	// transfer the signature verifier from the gin context to the request context
-	ctx := c.Request.Context()
-	verifier, signed := c.Get(string(util.APRequestingPublicKeyVerifier))
-	if signed {
-		ctx = context.WithValue(ctx, util.APRequestingPublicKeyVerifier, verifier)
-	}
+	ctx := populateContext(c)
 
-	status, err := m.processor.GetFediStatus(ctx, requestedUsername, requestedStatusID, c.Request.URL) // handles auth as well
-	if err != nil {
-		l.Info(err.Error())
-		c.JSON(err.Code(), gin.H{"error": err.Safe()})
+	status, errWithCode := m.processor.GetFediStatus(ctx, requestedUsername, requestedStatusID, c.Request.URL)
+	if errWithCode != nil {
+		l.Info(errWithCode.Error())
+		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
 		return
 	}
 

internal/api/s2s/user/user.go

@@ -61,13 +61,6 @@ const (
 	UsersStatusRepliesPath = UsersStatusPath + "/replies"
 )
 
-// ActivityPubAcceptHeaders represents the Accept headers mentioned here:
-// https://www.w3.org/TR/activitypub/#retrieving-objects
-var ActivityPubAcceptHeaders = []string{
-	`application/activity+json`,
-	`application/ld+json; profile="https://www.w3.org/ns/activitystreams"`,
-}
-
 // Module implements the FederationAPIModule interface
 type Module struct {
 	config    *config.Config

internal/api/s2s/user/userget.go

@@ -19,14 +19,12 @@
 package user
 
 import (
-	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
 	"github.com/sirupsen/logrus"
-	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 // UsersGETHandler should be served at https://example.org/users/:username.
@@ -50,25 +48,19 @@ func (m *Module) UsersGETHandler(c *gin.Context) {
 		return
 	}
 
-	// make sure this actually an AP request
-	format := c.NegotiateFormat(ActivityPubAcceptHeaders...)
-	if format == "" {
-		c.JSON(http.StatusNotAcceptable, gin.H{"error": "could not negotiate format with given Accept header(s)"})
+	format, err := negotiateFormat(c)
+	if err != nil {
+		c.JSON(http.StatusNotAcceptable, gin.H{"error": fmt.Sprintf("could not negotiate format with given Accept header(s): %s", err)})
 		return
 	}
 	l.Tracef("negotiated format: %s", format)
 
-	// transfer the signature verifier from the gin context to the request context
-	ctx := c.Request.Context()
-	verifier, signed := c.Get(string(util.APRequestingPublicKeyVerifier))
-	if signed {
-		ctx = context.WithValue(ctx, util.APRequestingPublicKeyVerifier, verifier)
-	}
+	ctx := populateContext(c)
 
-	user, err := m.processor.GetFediUser(ctx, requestedUsername, c.Request.URL) // GetFediUser handles auth as well
-	if err != nil {
-		l.Info(err.Error())
-		c.JSON(err.Code(), gin.H{"error": err.Safe()})
+	user, errWithCode := m.processor.GetFediUser(ctx, requestedUsername, c.Request.URL) // GetFediUser handles auth as well
+	if errWithCode != nil {
+		l.Info(errWithCode.Error())
+		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
 		return
 	}
 

internal/api/security/signaturecheck.go

@@ -11,13 +11,10 @@ import (
 
 // SignatureCheck checks whether an incoming http request has been signed. If so, it will check if the domain
 // that signed the request is permitted to access the server. If it is permitted, the handler will set the key
-// verifier in the gin context for use down the line.
+// verifier and the signature in the gin context for use down the line.
 func (m *Module) SignatureCheck(c *gin.Context) {
 	l := m.log.WithField("func", "DomainBlockChecker")
 
-	// set this extra field for signature validation
-	c.Request.Header.Set("host", m.config.Host)
-
 	// create the verifier from the request
 	// if the request is signed, it will have a signature header
 	verifier, err := httpsig.NewVerifier(c.Request)
@@ -43,8 +40,12 @@ func (m *Module) SignatureCheck(c *gin.Context) {
 				return
 			}
 
-			// set the verifier on the context here to save some work further down the line
+			// set the verifier and signature on the context here to save some work further down the line
 			c.Set(string(util.APRequestingPublicKeyVerifier), verifier)
+			signature := c.GetHeader("Signature")
+			if signature != "" {
+				c.Set(string(util.APRequestingPublicKeySignature), signature)
+			}
 		}
 	}
 }

internal/federation/authenticate.go

@@ -102,10 +102,6 @@ func getPublicKeyFromResponse(c context.Context, b []byte, keyID *url.URL) (voca
 // Authenticate in this case is defined as making sure that the http request is actually signed by whoever claims
 // to have signed it, by fetching the public key from the signature and checking it against the remote public key.
 //
-// To avoid making unnecessary http calls towards blocked domains, this function *does* bail early if an instance-level domain block exists
-// for the request from the incoming domain. However, it does not check whether individual blocks exist between the requesting user or domain
-// and the requested user: this should be done elsewhere.
-//
 // The provided username will be used to generate a transport for making remote requests/derefencing the public key ID of the request signature.
 // Ideally you should pass in the username of the user *being requested*, so that the remote server can decide how to handle the request based on who's making it.
 // Ie., if the request on this server is for https://example.org/users/some_username then you should pass in the username 'some_username'.
@@ -135,6 +131,19 @@ func (f *federator) AuthenticateFederatedRequest(ctx context.Context, requestedU
 		return nil, false, nil // couldn't extract the verifier
 	}
 
+	// we should have the signature itself set too
+	si := ctx.Value(util.APRequestingPublicKeySignature)
+	if vi == nil {
+		l.Debug("request wasn't signed")
+		return nil, false, nil // request wasn't signed
+	}
+
+	signature, ok := si.(string)
+	if !ok {
+		l.Debug("couldn't extract signature")
+		return nil, false, nil // couldn't extract the signature
+	}
+
 	requestingPublicKeyID, err := url.Parse(verifier.KeyId())
 	if err != nil {
 		l.Debug("couldn't parse public key URL")
@@ -227,13 +236,14 @@ func (f *federator) AuthenticateFederatedRequest(ctx context.Context, requestedU
 
 	for _, algo := range algos {
 		l.Tracef("trying algo: %s", algo)
-		if err := verifier.Verify(publicKey, algo); err == nil {
+		err := verifier.Verify(publicKey, algo)
+		if err == nil {
 			l.Tracef("authentication for %s PASSED with algorithm %s", pkOwnerURI, algo)
 			return pkOwnerURI, true, nil
 		}
 		l.Tracef("authentication for %s NOT PASSED with algorithm %s: %s", pkOwnerURI, algo, err)
 	}
 
-	l.Infof("authentication not passed for %s", pkOwnerURI)
+	l.Infof("authentication not passed for public key owner %s; signature value was '%s'", pkOwnerURI, signature)
 	return nil, false, nil
 }

internal/federation/federator_test.go

@@ -128,12 +128,13 @@ func (suite *ProtocolTestSuite) TestAuthenticatePostInbox() {
 	ctxWithAccount := context.WithValue(ctx, util.APAccount, inboxAccount)
 	ctxWithActivity := context.WithValue(ctxWithAccount, util.APActivity, activity)
 	ctxWithVerifier := context.WithValue(ctxWithActivity, util.APRequestingPublicKeyVerifier, verifier)
+	ctxWithSignature := context.WithValue(ctxWithVerifier, util.APRequestingPublicKeySignature, activity.SignatureHeader)
 
 	// we can pass this recorder as a writer and read it back after
 	recorder := httptest.NewRecorder()
 
 	// trigger the function being tested, and return the new context it creates
-	newContext, authed, err := federator.AuthenticatePostInbox(ctxWithVerifier, recorder, request)
+	newContext, authed, err := federator.AuthenticatePostInbox(ctxWithSignature, recorder, request)
 	assert.NoError(suite.T(), err)
 	assert.True(suite.T(), authed)
 

internal/util/uri.go

@@ -72,6 +72,8 @@ const (
 	APRequestingActorIRI APContextKey = "requestingActorIRI"
 	// APRequestingPublicKeyVerifier can be used to set and retrieve the public key verifier of an incoming federation request.
 	APRequestingPublicKeyVerifier APContextKey = "requestingPublicKeyVerifier"
+	// APRequestingPublicKeySignature can be used to set and retrieve the value of the signature header of an incoming federation request.
+	APRequestingPublicKeySignature APContextKey = "requestingPublicKeySignature"
 	// APFromFederatorChanKey can be used to pass a pointer to the fromFederator channel into the federator for use in callbacks.
 	APFromFederatorChanKey APContextKey = "fromFederatorChan"
 )