Add support for sending SSH2_MSG_UNIMPLEMENTED for unrecognised

messages; also do something with the debugging messages sent as
SSH2_MSG_DEBUG.

git-svn-id: svn://svn.tartarus.org/sgt/putty@1544 cda61777-01e9-0310-a592-d414129be87e

diff --git a/ssh.c b/ssh.c
index 22b8f5e..01c5caa 100644 (file)
--- a/ssh.c
+++ b/ssh.c
@@ -309,6 +309,18 @@ extern void pfd_confirm(Socket s);
 extern void pfd_unthrottle(Socket s);
 extern void pfd_override_throttle(Socket s, int enable);
 
+static void ssh2_pkt_init(int pkt_type);
+static void ssh2_pkt_addbool(unsigned char value);
+static void ssh2_pkt_adduint32(unsigned long value);
+static void ssh2_pkt_addstring_start(void);
+static void ssh2_pkt_addstring_str(char *data);
+static void ssh2_pkt_addstring_data(char *data, int len);
+static void ssh2_pkt_addstring(char *data);
+static char *ssh2_mpint_fmt(Bignum b, int *len);
+static void ssh2_pkt_addmp(Bignum b);
+static int ssh2_pkt_construct(void);
+static void ssh2_pkt_send(void);
+
 /*
  * Buffer management constants. There are several of these for
  * various different purposes:
@@ -770,8 +782,8 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen)
        pktin.type == SSH1_MSG_DEBUG ||
        pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
        pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
-       long strlen = GET_32BIT(pktin.body);
-       if (strlen + 4 != pktin.length) {
+       long stringlen = GET_32BIT(pktin.body);
+       if (stringlen + 4 != pktin.length) {
            bombout(("Received data packet with bogus string length"));
            crReturn(0);
        }
@@ -780,12 +792,12 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen)
     if (pktin.type == SSH1_MSG_DEBUG) {
        /* log debug message */
        char buf[80];
-       int strlen = GET_32BIT(pktin.body);
+       int stringlen = GET_32BIT(pktin.body);
        strcpy(buf, "Remote: ");
-       if (strlen > 70)
-           strlen = 70;
-       memcpy(buf + 8, pktin.body + 4, strlen);
-       buf[8 + strlen] = '\0';
+       if (stringlen > 70)
+           stringlen = 70;
+       memcpy(buf + 8, pktin.body + 4, stringlen);
+       buf[8 + stringlen] = '\0';
        logevent(buf);
        goto next_packet;
     } else if (pktin.type == SSH1_MSG_IGNORE) {
@@ -945,36 +957,105 @@ static int ssh2_rdpkt(unsigned char **data, int *datalen)
     log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
               pktin.data+6, pktin.length-6);
 
-    if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
-       goto next_packet;              /* FIXME: print DEBUG message */
-
-    if (pktin.type == SSH2_MSG_DISCONNECT) {
-       /* log reason code in disconnect message */
-       char buf[256];
-       int reason = GET_32BIT(pktin.data + 6);
-       unsigned msglen = GET_32BIT(pktin.data + 10);
-       unsigned nowlen;
-       if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
-           sprintf(buf, "Received disconnect message (%s)",
-                   ssh2_disconnect_reasons[reason]);
-       } else {
-           sprintf(buf, "Received disconnect message (unknown type %d)",
-                   reason);
+    switch (pktin.type) {
+        /*
+         * These packets we must handle instantly.
+         */
+      case SSH2_MSG_DISCONNECT:
+        {
+            /* log reason code in disconnect message */
+            char buf[256];
+            int reason = GET_32BIT(pktin.data + 6);
+            unsigned msglen = GET_32BIT(pktin.data + 10);
+            unsigned nowlen;
+            if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
+                sprintf(buf, "Received disconnect message (%s)",
+                        ssh2_disconnect_reasons[reason]);
+            } else {
+                sprintf(buf, "Received disconnect message (unknown type %d)",
+                        reason);
+            }
+            logevent(buf);
+            strcpy(buf, "Disconnection message text: ");
+            nowlen = strlen(buf);
+            if (msglen > sizeof(buf) - nowlen - 1)
+                msglen = sizeof(buf) - nowlen - 1;
+            memcpy(buf + nowlen, pktin.data + 14, msglen);
+            buf[nowlen + msglen] = '\0';
+            logevent(buf);
+            bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
+                     reason,
+                     (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
+                     ssh2_disconnect_reasons[reason] : "unknown",
+                     buf+nowlen));
+            crReturn(0);
+        }
+        break;
+      case SSH2_MSG_IGNORE:
+       goto next_packet;
+      case SSH2_MSG_DEBUG:
+       {
+           /* log the debug message */
+           char buf[512];
+           /* int display = pktin.body[6]; */
+           int stringlen = GET_32BIT(pktin.data+7);
+           int prefix;
+           strcpy(buf, "Remote debug message: ");
+           prefix = strlen(buf);
+           if (stringlen > sizeof(buf)-prefix-1)
+               stringlen = sizeof(buf)-prefix-1;
+           memcpy(buf + prefix, pktin.data + 11, stringlen);
+           buf[prefix + stringlen] = '\0';
+           logevent(buf);
        }
-       logevent(buf);
-       strcpy(buf, "Disconnection message text: ");
-       nowlen = strlen(buf);
-       if (msglen > sizeof(buf) - nowlen - 1)
-           msglen = sizeof(buf) - nowlen - 1;
-       memcpy(buf + nowlen, pktin.data + 14, msglen);
-       buf[nowlen + msglen] = '\0';
-       logevent(buf);
-       bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
-                reason,
-                (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
-                ssh2_disconnect_reasons[reason] : "unknown",
-                buf+nowlen));
-       crReturn(0);
+        goto next_packet;              /* FIXME: print the debug message */
+
+        /*
+         * These packets we need do nothing about here.
+         */
+      case SSH2_MSG_UNIMPLEMENTED:
+      case SSH2_MSG_SERVICE_REQUEST:
+      case SSH2_MSG_SERVICE_ACCEPT:
+      case SSH2_MSG_KEXINIT:
+      case SSH2_MSG_NEWKEYS:
+      case SSH2_MSG_KEXDH_INIT:
+      case SSH2_MSG_KEXDH_REPLY:
+      /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
+      /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
+      case SSH2_MSG_KEX_DH_GEX_INIT:
+      case SSH2_MSG_KEX_DH_GEX_REPLY:
+      case SSH2_MSG_USERAUTH_REQUEST:
+      case SSH2_MSG_USERAUTH_FAILURE:
+      case SSH2_MSG_USERAUTH_SUCCESS:
+      case SSH2_MSG_USERAUTH_BANNER:
+      case SSH2_MSG_USERAUTH_PK_OK:
+      /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
+      /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
+      case SSH2_MSG_USERAUTH_INFO_RESPONSE:
+      case SSH2_MSG_GLOBAL_REQUEST:
+      case SSH2_MSG_REQUEST_SUCCESS:
+      case SSH2_MSG_REQUEST_FAILURE:
+      case SSH2_MSG_CHANNEL_OPEN:
+      case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
+      case SSH2_MSG_CHANNEL_OPEN_FAILURE:
+      case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
+      case SSH2_MSG_CHANNEL_DATA:
+      case SSH2_MSG_CHANNEL_EXTENDED_DATA:
+      case SSH2_MSG_CHANNEL_EOF:
+      case SSH2_MSG_CHANNEL_CLOSE:
+      case SSH2_MSG_CHANNEL_REQUEST:
+      case SSH2_MSG_CHANNEL_SUCCESS:
+      case SSH2_MSG_CHANNEL_FAILURE:
+        break;
+
+        /*
+         * For anything else we send SSH2_MSG_UNIMPLEMENTED.
+         */
+      default:
+       ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
+       ssh2_pkt_adduint32(st->incoming_sequence - 1);
+       ssh2_pkt_send();
+        break;
     }
 
     crFinish(0);