internal: check ssh in SendChannelTerminalResize

It was the one channel sender that read ssh->defaultPeerChannelId
without a NULL check. It now returns WS_BAD_ARGUMENT for a NULL ssh and
logs entry and exit like its siblings.

- add TestTerminalResizeNullSsh to regress.test

Issue: F-14769

src/internal.c

@@ -24593,6 +24593,11 @@ int SendChannelTerminalResize(WOLFSSH* ssh, word32 columns, word32 rows,
     const char* cType = "window-change";
     word32 typeSz = 0;
 
+    WLOG(WS_LOG_DEBUG, "Entering SendChannelTerminalResize()");
+
+    if (ssh == NULL)
+        ret = WS_BAD_ARGUMENT;
+
     if (ret == WS_SUCCESS) {
         channel = ChannelFind(ssh,
                 ssh->defaultPeerChannelId, WS_CHANNEL_ID_PEER);
@@ -24641,6 +24646,7 @@ int SendChannelTerminalResize(WOLFSSH* ssh, word32 columns, word32 rows,
     if (ret == WS_SUCCESS)
         ret = wolfSSH_SendPacket(ssh);
 
+    WLOG(WS_LOG_DEBUG, "Leaving SendChannelTerminalResize(), ret = %d", ret);
     return ret;
 }
 

tests/regress.c

@@ -15394,6 +15394,12 @@ static void TestTerminalResizeBlockedAfterDisconnect(void)
     wolfSSH_free(ssh);
     wolfSSH_CTX_free(ctx);
 }
+
+static void TestTerminalResizeNullSsh(void)
+{
+    AssertIntEQ(SendChannelTerminalResize(NULL, 80, 24, 0, 0),
+            WS_BAD_ARGUMENT);
+}
 #endif /* WOLFSSH_TERM && !NO_FILESYSTEM */
 #endif /* !NO_WOLFSSH_CLIENT */
 
@@ -21087,6 +21093,7 @@ int main(int argc, char** argv)
 #if defined(WOLFSSH_TERM) && !defined(NO_FILESYSTEM) \
     && !defined(NO_WOLFSSH_CLIENT)
     TestTerminalResizeBlockedAfterDisconnect();
+    TestTerminalResizeNullSsh();
 #endif
 #if !(defined(WOLFSSH_NO_RSA) && defined(WOLFSSH_NO_ECDSA_SHA2_NISTP256))
     TestClientBuffersIdempotent();