Send server SSH version immediately after forwarding client version to prevent timeout

wssshtools/tunnel.c

@@ -349,6 +349,9 @@ void *forward_tcp_to_ws(void *arg) {
                 fflush(stdout);
             }
 
+            // Check if this is the SSH client version string
+            int is_client_version = (bytes_read >= 8 && strncmp(buffer, "SSH-2.0-", 8) == 0);
+
             // Convert to hex with bounds checking
             size_t hex_size = (size_t)bytes_read * 2 + 1;
             if (hex_size > BUFFER_SIZE) {
@@ -377,6 +380,29 @@ void *forward_tcp_to_ws(void *arg) {
                 }
                 break;
             }
+
+            // If this was the client SSH version, immediately send the server version to prevent timeout
+            if (is_client_version) {
+                const char *server_version = "SSH-2.0-OpenSSH_10.0p2 Debian-8\r\n";
+                size_t version_len = strlen(server_version);
+                if (debug) {
+                    printf("[DEBUG - TCPConnection] Sending server version immediately after client version\n");
+                    fflush(stdout);
+                }
+                ssize_t sent = send(client_sock, server_version, version_len, 0);
+                if (sent > 0) {
+                    if (debug) {
+                        printf("[DEBUG] Sent %zd bytes of server version\n", sent);
+                        fflush(stdout);
+                    }
+                    // Set flag to skip duplicate server version
+                    pthread_mutex_lock(&tunnel_mutex);
+                    if (active_tunnel) {
+                        active_tunnel->server_version_sent = 1;
+                    }
+                    pthread_mutex_unlock(&tunnel_mutex);
+                }
+            }
         }
     }
 

wssshtools/wsssh.c

@@ -477,32 +477,17 @@ int main(int argc, char *argv[]) {
     pthread_mutex_lock(&tunnel_mutex);
     active_tunnel->local_sock = accepted_sock;
 
-    // Send server version immediately to prevent SSH client timeout
-    const char *server_version = "SSH-2.0-OpenSSH_10.0p2 Debian-8\r\n";
-    size_t version_len = strlen(server_version);
-    if (config.debug) {
-        printf("[DEBUG - Tunnel] Sending server version immediately to SSH client\n");
-        fflush(stdout);
-    }
-    ssize_t sent = send(accepted_sock, server_version, version_len, 0);
-    if (sent > 0) {
-        if (config.debug) {
-            printf("[DEBUG] Sent %zd bytes of server version to SSH client\n", sent);
-            fflush(stdout);
-        }
-    }
-
     // Send any buffered data to the SSH client immediately
     if (active_tunnel->incoming_buffer && active_tunnel->incoming_buffer->used > 0) {
         if (config.debug) {
             printf("[DEBUG - Tunnel] Sending %zu bytes of buffered server response to SSH client\n", active_tunnel->incoming_buffer->used);
             fflush(stdout);
         }
-        ssize_t sent2 = send(accepted_sock, active_tunnel->incoming_buffer->buffer, active_tunnel->incoming_buffer->used, 0);
-        if (sent2 > 0) {
-            frame_buffer_consume(active_tunnel->incoming_buffer, sent2);
+        ssize_t sent = send(accepted_sock, active_tunnel->incoming_buffer->buffer, active_tunnel->incoming_buffer->used, 0);
+        if (sent > 0) {
+            frame_buffer_consume(active_tunnel->incoming_buffer, sent);
             if (config.debug) {
-                printf("[DEBUG] Sent %zd bytes of buffered server response to SSH client\n", sent2);
+                printf("[DEBUG] Sent %zd bytes of buffered server response to SSH client\n", sent);
                 fflush(stdout);
             }
         }