From 201029797b260eee894b12d488bce6022290bf67 Mon Sep 17 00:00:00 2001
From: JacobBarthelmeh <jacob@wolfssl.com>
Date: Fri, 18 Jul 2025 15:43:26 -0600
Subject: [PATCH] only send ext info once after SSH_MSG_NEWKEYS

---
 src/internal.c     | 6 +++++-
 wolfssh/internal.h | 1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/internal.c b/src/internal.c
index 080ded6f3..912315ca2 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -4080,7 +4080,7 @@ static int DoKexInit(WOLFSSH* ssh, byte* buf, word32 len, word32* idx)
     if (ret == WS_SUCCESS) {
         /* Only checking for this is we are server. Our client does
          * not have anything to say to a server, yet. */
-        if (side == WOLFSSH_ENDPOINT_SERVER) {
+        if (side == WOLFSSH_ENDPOINT_SERVER && !ssh->extInfoSent) {
             byte extInfo;
 
             /* Match the client accepts extInfo. */
@@ -13216,6 +13216,10 @@ int SendExtInfo(WOLFSSH* ssh)
     }
 
     if (ret == WS_SUCCESS) {
+        ssh->sendExtInfo = 0;
+        ssh->extInfoSent = 1; /* RFC 8308 section 2.4 ext. info should only be
+                               * sent after SSH_MSG_NEWKEYS or after
+                               * SSH_MSG_USERAUTH_SUCCESS. Not on re-key */
         ret = wolfSSH_SendPacket(ssh);
     }
 
diff --git a/wolfssh/internal.h b/wolfssh/internal.h
index 1b60139a1..26c3a05b0 100644
--- a/wolfssh/internal.h
+++ b/wolfssh/internal.h
@@ -844,6 +844,7 @@ struct WOLFSSH {
     byte  sendTerminalRequest;
     byte userAuthPkDone;
     byte sendExtInfo;
+    byte extInfoSent; /* track if the ext info has already been sent */
     byte* peerSigId;
     word32 peerSigIdSz;