SSH-AGENT Touchup

1. Add function to request the channel ID for the last message received.
2. Changed the send channel functions to use the self channel ID rather
   than the peer's channel ID.
3. Modified client and echoserver to use the channel ID for the agent
   to send messages.
4. Modify client to receive the entire message from the agent before
   trying to relay it to the peer.

examples/client/client.c

@@ -512,6 +512,14 @@ static THREAD_RET readInput(void* in)
 }
 
 
+#ifdef WOLFSSH_AGENT
+static inline void ato32(const byte* c, word32* u32)
+{
+    *u32 = (c[0] << 24) | (c[1] << 16) | (c[2] << 8) | c[3];
+}
+#endif
+
+
 static THREAD_RET readPeer(void* in)
 {
     byte buf[80];
@@ -555,18 +563,30 @@ static THREAD_RET readPeer(void* in)
                     if (ret == WS_CHAN_RXD) {
                         byte agentBuf[512];
                         int rxd, txd;
+                        word32 channel = 0;
 
-                        rxd = wolfSSH_ChannelIdRead(args->ssh, 1,
+                        wolfSSH_GetLastRxId(args->ssh, &channel);
+                        rxd = wolfSSH_ChannelIdRead(args->ssh, channel,
                                 agentBuf, sizeof(agentBuf));
-                        if (rxd > 0) {
+                        if (rxd > 4) {
+                            word32 msgSz = 0;
+
+                            ato32(agentBuf, &msgSz);
+                            if (msgSz > (word32)rxd - 4) {
+                                rxd += wolfSSH_ChannelIdRead(args->ssh, channel,
+                                        agentBuf + rxd,
+                                        sizeof(agentBuf) - rxd);
+                            }
+
                             txd = rxd;
                             rxd = sizeof(agentBuf);
                             ret = wolfSSH_AGENT_Relay(args->ssh,
                                     agentBuf, (word32*)&txd,
                                     agentBuf, (word32*)&rxd);
-                            if (ret == WS_SUCCESS)
-                                wolfSSH_ChannelIdSend(args->ssh, 1,
+                            if (ret == WS_SUCCESS) {
+                                ret = wolfSSH_ChannelIdSend(args->ssh, channel,
                                         agentBuf, rxd);
+                            }
                         }
                         WMEMSET(agentBuf, 0, sizeof(agentBuf));
                         continue;

examples/echoserver/echoserver.c

@@ -562,6 +562,7 @@ static int shell_worker(thread_ctx_t* threadCtx)
         BUF_T agent_buf;
         int agentFd = -1;
         int listenFd = threadCtx->agentCbCtx.listenFd;
+        word32 agentChannelId = 0;
 #endif
 
         #ifdef SHELL_DEBUG
@@ -789,7 +790,8 @@ static int shell_worker(thread_ctx_t* threadCtx)
                     }
                     #ifdef WOLFSSH_AGENT
                         if (rc == WS_CHAN_RXD) {
-                            cnt_r = wolfSSH_ChannelIdRead(ssh, 1,
+                            wolfSSH_GetLastRxId(ssh, &agentChannelId);
+                            cnt_r = wolfSSH_ChannelIdRead(ssh, agentChannelId,
                                     (byte*)agent_buf.buf, cnt_r);
                             if (cnt_r <= 0)
                                 break;
@@ -839,7 +841,7 @@ static int shell_worker(thread_ctx_t* threadCtx)
                         #ifdef SHELL_DEBUG
                             buf_dump(agent_buf.buf+agent_buf.rdidx, cnt_r);
                         #endif
-                        cnt_w = wolfSSH_ChannelIdSend(ssh, 1,
+                        cnt_w = wolfSSH_ChannelIdSend(ssh, agentChannelId,
                                 (byte*)agent_buf.buf + agent_buf.rdidx, cnt_r);
                         if (cnt_w > 0) {
                             agent_buf.rdidx += cnt_r;

src/internal.c

@@ -8462,7 +8462,7 @@ int SendChannelClose(WOLFSSH* ssh, word32 peerChannelId)
 }
 
 
-int SendChannelData(WOLFSSH* ssh, word32 peerChannel,
+int SendChannelData(WOLFSSH* ssh, word32 channelId,
                     byte* data, word32 dataSz)
 {
     byte* output;
@@ -8486,9 +8486,9 @@ int SendChannelData(WOLFSSH* ssh, word32 peerChannel,
     }
 
     if (ret == WS_SUCCESS) {
-        channel = ChannelFind(ssh, peerChannel, WS_CHANNEL_ID_PEER);
+        channel = ChannelFind(ssh, channelId, WS_CHANNEL_ID_SELF);
         if (channel == NULL) {
-            WLOG(WS_LOG_DEBUG, "Invalid peer channel");
+            WLOG(WS_LOG_DEBUG, "Invalid channel");
             ret = WS_INVALID_CHANID;
         }
     }
@@ -8552,7 +8552,7 @@ int SendChannelData(WOLFSSH* ssh, word32 peerChannel,
 }
 
 
-int SendChannelWindowAdjust(WOLFSSH* ssh, word32 peerChannel,
+int SendChannelWindowAdjust(WOLFSSH* ssh, word32 channelId,
                             word32 bytesToAdd)
 {
     byte* output;
@@ -8565,9 +8565,9 @@ int SendChannelWindowAdjust(WOLFSSH* ssh, word32 peerChannel,
     if (ssh == NULL)
         ret = WS_BAD_ARGUMENT;
 
-    channel = ChannelFind(ssh, peerChannel, WS_CHANNEL_ID_PEER);
+    channel = ChannelFind(ssh, channelId, WS_CHANNEL_ID_SELF);
     if (channel == NULL) {
-        WLOG(WS_LOG_DEBUG, "Invalid peer channel");
+        WLOG(WS_LOG_DEBUG, "Invalid channel");
         ret = WS_INVALID_CHANID;
     }
     if (ret == WS_SUCCESS)

src/ssh.c

@@ -1715,6 +1715,20 @@ int wolfSSH_worker(WOLFSSH* ssh, word32* channelId)
 }
 
 
+int wolfSSH_GetLastRxId(WOLFSSH* ssh, word32* channelId)
+{
+    int ret = WS_SUCCESS;
+
+    if (ssh == NULL || channelId == NULL)
+        ret = WS_ERROR;
+
+    if (ret == WS_SUCCESS)
+        *channelId = ssh->lastRxId;
+
+    return ret;
+}
+
+
 #ifdef WOLFSSH_FWD
 
 WOLFSSH_CHANNEL* wolfSSH_ChannelFwdNew(WOLFSSH* ssh,

wolfssh/ssh.h

@@ -63,6 +63,7 @@ WOLFSSH_API WOLFSSH* wolfSSH_new(WOLFSSH_CTX*);
 WOLFSSH_API void wolfSSH_free(WOLFSSH*);
 
 WOLFSSH_API int wolfSSH_worker(WOLFSSH*, word32*);
+WOLFSSH_API int wolfSSH_GetLastRxId(WOLFSSH*, word32*);
 
 WOLFSSH_API int wolfSSH_set_fd(WOLFSSH*, WS_SOCKET_T);
 WOLFSSH_API WS_SOCKET_T wolfSSH_get_fd(const WOLFSSH*);