1 files changed, 71 insertions, 0 deletions
diff --git a/internal/transport/controller.go b/internal/transport/controller.go
new file mode 100644
index 000000000..525141025
--- /dev/null
+++ b/internal/transport/controller.go
@@ -0,0 +1,71 @@
+/*
+   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 transport
+
+import (
+	"crypto"
+	"fmt"
+
+	"github.com/go-fed/activity/pub"
+	"github.com/go-fed/httpsig"
+	"github.com/sirupsen/logrus"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+)
+
+// Controller generates transports for use in making federation requests to other servers.
+type Controller interface {
+	NewTransport(pubKeyID string, privkey crypto.PrivateKey) (pub.Transport, error)
+}
+
+type controller struct {
+	config   *config.Config
+	clock    pub.Clock
+	client   pub.HttpClient
+	appAgent string
+}
+
+// NewController returns an implementation of the Controller interface for creating new transports
+func NewController(config *config.Config, clock pub.Clock, client pub.HttpClient, log *logrus.Logger) Controller {
+	return &controller{
+		config:   config,
+		clock:    clock,
+		client:   client,
+		appAgent: fmt.Sprintf("%s %s", config.ApplicationName, config.Host),
+	}
+}
+
+// NewTransport returns a new http signature transport with the given public key id (a URL), and the given private key.
+func (c *controller) NewTransport(pubKeyID string, privkey crypto.PrivateKey) (pub.Transport, error) {
+	prefs := []httpsig.Algorithm{httpsig.RSA_SHA256, httpsig.RSA_SHA512}
+	digestAlgo := httpsig.DigestSha256
+	getHeaders := []string{"(request-target)", "date"}
+	postHeaders := []string{"(request-target)", "date", "digest"}
+
+	getSigner, _, err := httpsig.NewSigner(prefs, digestAlgo, getHeaders, httpsig.Signature)
+	if err != nil {
+		return nil, fmt.Errorf("error creating get signer: %s", err)
+	}
+
+	postSigner, _, err := httpsig.NewSigner(prefs, digestAlgo, postHeaders, httpsig.Signature)
+	if err != nil {
+		return nil, fmt.Errorf("error creating post signer: %s", err)
+	}
+
+	return pub.NewHttpSigTransport(c.client, c.appAgent, c.clock, getSigner, postSigner, pubKeyID, privkey), nil
+}