Initial import

Author: Adam Langley

README.md

@@ -0,0 +1,123 @@
+package bbssig
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/sha256"
+	"testing"
+)
+
+func TestMarshal(t *testing.T) {
+	priv, err := GenerateGroup(rand.Reader)
+	if err != nil {
+		t.Fatalf("failed to generate group: %s", err)
+	}
+
+	groupBytes := priv.Group.Marshal()
+	_, ok := new(Group).Unmarshal(groupBytes)
+	if !ok {
+		t.Error("failed to unmarshal group")
+	}
+
+	group2, ok := new(Group).Unmarshal(groupBytes)
+	if !ok {
+		t.Error("failed to unmarshal group")
+	}
+
+	if group2Bytes := group2.Marshal(); !bytes.Equal(groupBytes, group2Bytes) {
+		t.Error("reserialising group produces different result")
+	}
+
+	_, ok = new(PrivateKey).Unmarshal(group2, priv.Marshal())
+	if !ok {
+		t.Error("failed to unmarshal private key")
+	}
+}
+
+func TestSign(t *testing.T) {
+	priv, err := GenerateGroup(rand.Reader)
+	if err != nil {
+		t.Fatalf("failed to generate group: %s", err)
+	}
+
+	group := priv.Group
+	member, err := priv.NewMember(rand.Reader)
+	if err != nil {
+		t.Fatalf("failed to add member to group: %s", err)
+	}
+
+	msg := []byte("hello world")
+	h := sha256.New()
+	h.Write(msg)
+	digest := h.Sum(nil)
+
+	ok := false
+	groupBytes := group.Marshal()
+	group, ok = new(Group).Unmarshal(groupBytes)
+	if !ok {
+		t.Fatalf("failed to unmarshal group")
+	}
+
+	sig, err := member.Sign(rand.Reader, digest, h)
+	if err != nil {
+		t.Fatalf("failed to sign message: %s", err)
+	}
+
+	if !group.Verify(digest, h, sig) {
+		t.Errorf("signature failed to verify")
+	}
+
+	digest[1] ^= 0x80
+	if group.Verify(digest, h, sig) {
+		t.Errorf("signature always verifies")
+	}
+	digest[1] ^= 0x80
+
+	tag, ok := priv.Open(sig)
+	if !ok {
+		t.Fatalf("failed to open signature")
+	}
+
+	if !bytes.Equal(tag, member.Tag()) {
+		t.Errorf("Open returned wrong tag value")
+	}
+
+	member2, err := priv.NewMember(rand.Reader)
+	if err != nil {
+		t.Fatalf("failed to add second member: %s", err)
+	}
+	rev := priv.GenerateRevocation(member)
+
+	group.Update(rev)
+	if group.Verify(digest, h, sig) {
+		t.Errorf("signature still verifies after revocation")
+	}
+
+	if member.Update(rev) {
+		t.Errorf("revoked key successfully updated")
+	}
+
+	sig2, err := member2.Sign(rand.Reader, digest, h)
+	if err != nil {
+		t.Fatalf("failed to sign second message: %s", err)
+	}
+
+	if group.Verify(digest, h, sig2) {
+		t.Errorf("signature verified before member key updated")
+	}
+
+	member2.Group.Update(rev)
+
+	if !member2.Update(rev) {
+		t.Errorf("unrevoked member failed to update")
+	}
+
+	sig3, err := member2.Sign(rand.Reader, digest, h)
+	if err != nil {
+		t.Fatalf("failed to sign second message: %s", err)
+	}
+
+	if !group.Verify(digest, h, sig3) {
+		t.Errorf("updated signature failed to verify")
+	}
+}

bbssig/bbssig.go

@@ -0,0 +1,7 @@
+Short-term TODOs:
+
+Allow for immediate deletion.
+Expose server queue length in fetches
+Delete messages while UI is open.
+ ? Add delay to server responses.
+Compress messages