From 3f497f2eed56eae5cfa2e01daead01ad3f30d933 Mon Sep 17 00:00:00 2001
From: Alexandre Petit <62973006+AlexpFr@users.noreply.github.com>
Date: Mon, 9 Mar 2026 16:36:13 +0100
Subject: [PATCH] SSH Agent: Check writeString() return value in OpenSSHKey

Validate `stream.writeString(m_certificateType)` success and set m_error on
failure, consistent with other write*() calls. Prevents partial stream writes
---
 src/sshagent/OpenSSHKey.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/sshagent/OpenSSHKey.cpp b/src/sshagent/OpenSSHKey.cpp
index fd0c7447a..c5673ccdb 100644
--- a/src/sshagent/OpenSSHKey.cpp
+++ b/src/sshagent/OpenSSHKey.cpp
@@ -724,7 +724,10 @@ bool OpenSSHKey::writeCertificate(BinaryStream& stream, const bool addCertificat
         return true;
     }
 
-    stream.writeString(m_certificateType);
+    if (!stream.writeString(m_certificateType)) {
+        m_error = tr("Unexpected EOF when writing certificate");
+        return false;
+    }  
 
     if (!stream.writeString(m_rawCertificateData)) {
         m_error = tr("Unexpected EOF when writing certificate");