Add a signature package and stsigtool CLI utility

lib/signature/signature_test.go

@@ -0,0 +1,81 @@
+// Copyright (C) 2015 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package signature_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/syncthing/syncthing/lib/signature"
+)
+
+var (
+	// A private key for signing
+	privKey = []byte(`-----BEGIN EC PRIVATE KEY-----
+MIHbAgEBBEFGXB1IgefFF6kSyE17xIAU7fDIn07sPnGf1kLOCVrEZyUbnAmNFk8u
+lUt/knnvo+Gw1i9ucFjmtYtzDevrhSlG5aAHBgUrgQQAI6GBiQOBhgAEASlcbcgJ
+4PN+TSnAYiMlA0I/PRtFrDCgrt27K7hR+U7Afjc4KqW+QYwoRLvxueNh7gUK+zc0
+Aqrk3z+O1epiQTq8ACikHUXsx/bSzEFlPdMygUAAj3hChlgCL6/vOocuRUbtAqc6
+Zr0L9px+J4L0K+uqhyhKya7y6QLJrYPovFq3A7AK
+-----END EC PRIVATE KEY-----`)
+
+	// The matching public key
+	pubKey = []byte(`-----BEGIN EC PUBLIC KEY-----
+MIGbMBAGByqGSM49AgEGBSuBBAAjA4GGAAQBKVxtyAng835NKcBiIyUDQj89G0Ws
+MKCu3bsruFH5TsB+Nzgqpb5BjChEu/G542HuBQr7NzQCquTfP47V6mJBOrwAKKQd
+RezH9tLMQWU90zKBQACPeEKGWAIvr+86hy5FRu0CpzpmvQv2nH4ngvQr66qHKErJ
+rvLpAsmtg+i8WrcDsAo=
+-----END EC PUBLIC KEY-----`)
+
+	// A signature of "this is a string to sign" created with the private key
+	// above
+	exampleSig = []byte(`-----BEGIN SIGNATURE-----
+MIGGAkFdHjdarlFOrtcnCqcb0BX7Mjjq/Sbgp4mopCxBwXmfamtCeRGhZJ5MikyD
+VXScaJ2Dq2Ov7L4/gTcYj9fZwcrWgQJBc7+tcw5fpO0/y8DNq0t3g9bqt2MkmoNm
+eSAM8Fze4usVXHEi+QeMuYM2IKeVPyAR3iyl5gflVul9NRXS3OPAH3A=
+-----END SIGNATURE-----`)
+)
+
+func TestGenerateKeys(t *testing.T) {
+	priv, pub, err := signature.GenerateKeys()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Contains(priv, []byte("PRIVATE KEY")) {
+		t.Fatal("should be a private key")
+	}
+	if !bytes.Contains(pub, []byte("PUBLIC KEY")) {
+		t.Fatal("should be a private key")
+	}
+}
+
+func TestSign(t *testing.T) {
+	data := bytes.NewReader([]byte("this is a string to sign"))
+
+	s, err := signature.Sign(privKey, data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Contains(s, []byte("SIGNATURE")) {
+		t.Error("should be a signature")
+	}
+}
+
+func TestVerify(t *testing.T) {
+	data := bytes.NewReader([]byte("this is a string to sign"))
+	err := signature.Verify(pubKey, exampleSig, data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	data = bytes.NewReader([]byte("thus is a string to sign"))
+	err = signature.Verify(pubKey, exampleSig, data)
+	if err == nil {
+		t.Fatal("signature should not match")
+	}
+}