From e3a3edc3ebc87d9f25b0b35e04611e5eff53eb40 Mon Sep 17 00:00:00 2001
From: Lukas Burkhalter <lukas.burkhalter@proton.ch>
Date: Thu, 20 Jun 2024 18:03:25 +0200
Subject: [PATCH] Remove existing randomized notations

---
 openpgp/packet/config.go    |  3 ++-
 openpgp/packet/signature.go | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/openpgp/packet/config.go b/openpgp/packet/config.go
index db5cfcfc..f3bff95f 100644
--- a/openpgp/packet/config.go
+++ b/openpgp/packet/config.go
@@ -366,7 +366,8 @@ func (c *Config) RandomizeSignaturesViaNotation() bool {
 	return *c.NonDeterministicSignaturesViaNotation
 }
 
-// Helper function to set a boolean pointer in the Config.
+// BoolPointer is a helper function to set a boolean pointer in the Config.
+// e.g., config.CheckPacketSequence = BoolPointer(true)
 func BoolPointer(value bool) *bool {
 	return &value
 }
diff --git a/openpgp/packet/signature.go b/openpgp/packet/signature.go
index bc21e571..60f8c064 100644
--- a/openpgp/packet/signature.go
+++ b/openpgp/packet/signature.go
@@ -881,6 +881,7 @@ func (sig *Signature) Sign(h hash.Hash, priv *PrivateKey, config *Config) (err e
 	sig.Version = priv.PublicKey.Version
 	sig.IssuerFingerprint = priv.PublicKey.Fingerprint
 	if priv.Version != 6 && config.RandomizeSignaturesViaNotation() {
+		sig.removeNotationsWithName(SaltNotationName)
 		salt, err := SignatureSaltForHash(sig.Hash, config.Random())
 		if err != nil {
 			return err
@@ -1421,3 +1422,17 @@ func SignatureSaltForHash(hash crypto.Hash, randReader io.Reader) ([]byte, error
 	}
 	return salt, nil
 }
+
+// removeNotationsWithName removes all notations in this signature with the given name.
+func (sig *Signature) removeNotationsWithName(name string) {
+	if sig == nil || sig.Notations == nil {
+		return
+	}
+	updatedNotations := make([]*Notation, 0, len(sig.Notations))
+	for _, notation := range sig.Notations {
+		if notation.Name != name {
+			updatedNotations = append(updatedNotations, notation)
+		}
+	}
+	sig.Notations = updatedNotations
+}