From a6a7066454980370b0d06845cdb53aba32975d7e Mon Sep 17 00:00:00 2001
From: Matt Morehouse <mattmorehouse@gmail.com>
Date: Thu, 27 Apr 2023 15:25:13 -0500
Subject: [PATCH 1/3] lnwire: add FuzzParseRawSignature test

Test parsing and serialization of raw DER-encoded signatures.
---
 lnwire/fuzz_test.go | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/lnwire/fuzz_test.go b/lnwire/fuzz_test.go
index f578663a3..b1392881e 100644
--- a/lnwire/fuzz_test.go
+++ b/lnwire/fuzz_test.go
@@ -822,3 +822,24 @@ func FuzzCustomMessage(f *testing.F) {
 		harness(t, data)
 	})
 }
+
+// FuzzParseRawSignature tests that our DER-encoded signature parsing does not
+// panic for arbitrary inputs and that serializing and reparsing the signatures
+// does not mutate them.
+func FuzzParseRawSignature(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		sig, err := NewSigFromRawSignature(data)
+		if err != nil {
+			return
+		}
+
+		sig2, err := NewSigFromRawSignature(sig.ToSignatureBytes())
+		if err != nil {
+			t.Fatalf("failed to reparse signature: %v", err)
+		}
+
+		if !reflect.DeepEqual(sig, sig2) {
+			t.Fatalf("signature mismatch: %v != %v", sig, sig2)
+		}
+	})
+}

From e198e6693fa281d448540f2ffabb09ef237f8499 Mon Sep 17 00:00:00 2001
From: Matt Morehouse <mattmorehouse@gmail.com>
Date: Fri, 28 Apr 2023 10:20:08 -0500
Subject: [PATCH 2/3] lnwire: add FuzzConvertFixedSignature test

Test conversion of fixed 64-byte signatures to DER-encoded signatures.
---
 lnwire/fuzz_test.go | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/lnwire/fuzz_test.go b/lnwire/fuzz_test.go
index b1392881e..53f152328 100644
--- a/lnwire/fuzz_test.go
+++ b/lnwire/fuzz_test.go
@@ -843,3 +843,39 @@ func FuzzParseRawSignature(f *testing.F) {
 		}
 	})
 }
+
+// FuzzConvertFixedSignature tests that conversion of fixed 64-byte signatures
+// to DER-encoded signatures does not panic and that parsing and reconverting
+// the signatures does not mutate them.
+func FuzzConvertFixedSignature(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		var sig Sig
+		if len(data) > len(sig) {
+			return
+		}
+		copy(sig[:], data)
+
+		derSig, err := sig.ToSignature()
+		if err != nil {
+			return
+		}
+
+		sig2, err := NewSigFromSignature(derSig)
+		if err != nil {
+			t.Fatalf("failed to parse signature: %v", err)
+		}
+
+		derSig2, err := sig2.ToSignature()
+		if err != nil {
+			t.Fatalf("failed to reconvert signature to DER: %v",
+				err)
+		}
+
+		derBytes := derSig.Serialize()
+		derBytes2 := derSig2.Serialize()
+		if !bytes.Equal(derBytes, derBytes2) {
+			t.Fatalf("signature mismatch: %v != %v", derBytes,
+				derBytes2)
+		}
+	})
+}

From 55aa7a7bb210dbfc0e1ccd1a5695fb887625b7d7 Mon Sep 17 00:00:00 2001
From: Matt Morehouse <mattmorehouse@gmail.com>
Date: Thu, 11 May 2023 16:58:39 -0500
Subject: [PATCH 3/3] docs: release note for #7649

---
 docs/release-notes/release-notes-0.17.0.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/docs/release-notes/release-notes-0.17.0.md b/docs/release-notes/release-notes-0.17.0.md
index cba104f89..a6fda9f46 100644
--- a/docs/release-notes/release-notes-0.17.0.md
+++ b/docs/release-notes/release-notes-0.17.0.md
@@ -54,6 +54,11 @@ unlock or create.
   `github.com/golang/protobuf/jsonpb`
   module](https://github.com/lightningnetwork/lnd/pull/7659).
 
+## Testing
+
+* [Added fuzz tests](https://github.com/lightningnetwork/lnd/pull/7649) for
+  signature parsing and conversion.
+
 # Contributors (Alphabetical Order)
 
 * Carla Kirk-Cohen
@@ -62,6 +67,7 @@ unlock or create.
 * Erik Arvstedt
 * hieblmi
 * Jordi Montes
+* Matt Morehouse
 * Michael Street
 * Oliver Gugger
 * ziggie1984