Attempt to ensure that everything passed to connection_fatal() is
[u/mdw/putty] / ssh.c
diff --git a/ssh.c b/ssh.c
index 8fac568..51bbf44 100644 (file)
--- a/ssh.c
+++ b/ssh.c
                       if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
                       { fprintf(stderr, "%s\n", s); fflush(stderr); } }
 
+/* logevent, only printf-formatted. */
+void logeventf(char *fmt, ...)
+{
+    va_list ap;
+    char stuff[200];
+
+    va_start(ap, fmt);
+    vsprintf(stuff, fmt, ap);
+    va_end(ap);
+    logevent(stuff);
+}
+
 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
                           (s ? sk_close(s), s = NULL : 0), \
-                          connection_fatal msg )
+                          logeventf msg, connection_fatal msg )
 
 #define SSH1_MSG_DISCONNECT                       1    /* 0x1 */
 #define SSH1_SMSG_PUBLIC_KEY                      2    /* 0x2 */
@@ -168,6 +180,7 @@ static const char *const ssh2_disconnect_reasons[] = {
 #define BUG_CHOKES_ON_SSH1_IGNORE                 1
 #define BUG_SSH2_HMAC                             2
 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD            4
+#define BUG_CHOKES_ON_RSA                        8
 
 static int ssh_pkt_ctx = 0;
 
@@ -309,6 +322,18 @@ 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 +795,8 @@ 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 +805,12 @@ 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) {
@@ -804,7 +829,7 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen)
            msglen = sizeof(buf) - nowlen - 1;
        memcpy(buf + nowlen, pktin.body + 4, msglen);
        buf[nowlen + msglen] = '\0';
-       logevent(buf);
+       /* logevent(buf); (this is now done within the bombout macro) */
        bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
        crReturn(0);
     }
@@ -945,36 +970,105 @@ 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);
@@ -1509,6 +1603,16 @@ static void ssh_detect_bugs(char *vstring)
        logevent("We believe remote version needs a plain SSH1 password");
     }
 
+    if (!strcmp(imp, "Cisco-1.25")) {
+       /*
+        * These versions apparently have no clue whatever about
+        * RSA authentication and will panic and die if they see
+        * an AUTH_RSA message.
+        */
+       ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
+       logevent("We believe remote version can't handle RSA authentication");
+    }
+
     if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
        !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
        !strncmp(imp, "2.1 ", 4)) {
@@ -1687,6 +1791,7 @@ static int ssh_closing(Plug plug, char *error_msg, int error_code,
     }
     if (error_msg) {
        /* A socket error has occurred. */
+       logevent(error_msg);
        connection_fatal(error_msg);
     } else {
        /* Otherwise, the remote side closed the connection normally. */
@@ -1780,9 +1885,11 @@ static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
        sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
        logevent(buf);
     }
-    s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr);
-    if ((err = sk_socket_error(s)))
+    s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
+    if ((err = sk_socket_error(s))) {
+       s = NULL;
        return err;
+    }
 
 #ifdef FWHACK
     sk_write(s, "connect ", 8);
@@ -2074,8 +2181,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
                            break;
                          case 3:
                          case 4:
-                           random_save_seed();
-                           exit(0);
+                           cleanup_exit(0);
                            break;
                          default:
                            if (((c >= ' ' && c <= '~') ||
@@ -2110,7 +2216,12 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
 
     crWaitUntil(ispkt);
 
-    tried_publickey = tried_agent = 0;
+    if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
+       /* We must not attempt PK auth. Pretend we've already tried it. */
+       tried_publickey = tried_agent = 1;
+    } else {
+       tried_publickey = tried_agent = 0;
+    }
     tis_auth_refused = ccard_auth_refused = 0;
     /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
     if (*cfg.keyfile) {
@@ -2345,6 +2456,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
                send_packet(SSH1_MSG_DISCONNECT,
                            PKT_STR, "No more passwords available to try",
                            PKT_END);
+               logevent("Unable to authenticate");
                connection_fatal("Unable to authenticate");
                ssh_state = SSH_STATE_CLOSED;
                crReturn(1);
@@ -2375,8 +2487,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
                        break;
                      case 3:
                      case 4:
-                       random_save_seed();
-                       exit(0);
+                       cleanup_exit(0);
                        break;
                      default:
                        if (pos < sizeof(password)-1)
@@ -3776,6 +3887,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
     static int we_are_in;
     static int num_prompts, echo;
     static char username[100];
+    static int got_username;
     static char pwprompt[200];
     static char password[100];
     static void *publickey_blob;
@@ -3820,6 +3932,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
      *    retype it!
      */
     username[0] = '\0';
+    got_username = FALSE;
     do {
        static int pos;
        static char c;
@@ -3828,7 +3941,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
         * Get a username.
         */
        pos = 0;
-       if (*username && !cfg.change_username) {
+       if (got_username && !cfg.change_username) {
            /*
             * We got a username last time round this loop, and
             * with change_username turned off we don't try to get
@@ -3874,8 +3987,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
                            break;
                          case 3:
                          case 4:
-                           random_save_seed();
-                           exit(0);
+                           cleanup_exit(0);
                            break;
                          default:
                            if (((c >= ' ' && c <= '~') ||
@@ -3899,6 +4011,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
                c_write_str(stuff);
            }
        }
+       got_username = TRUE;
 
        /*
         * Send an authentication request using method "none": (a)
@@ -4321,6 +4434,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
                            ("No more passwords available to try");
                        ssh2_pkt_addstring("en");       /* language tag */
                        ssh2_pkt_send();
+                       logevent("Unable to authenticate");
                        connection_fatal("Unable to authenticate");
                        ssh_state = SSH_STATE_CLOSED;
                        crReturnV;
@@ -4353,8 +4467,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
                                break;
                              case 3:
                              case 4:
-                               random_save_seed();
-                               exit(0);
+                               cleanup_exit(0);
                                break;
                              default:
                                if (pos < sizeof(password)-1)
@@ -5102,7 +5215,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
                    ssh2_pkt_addstring(buf);
                    ssh2_pkt_addstring("en");   /* language tag */
                    ssh2_pkt_send();
-                   connection_fatal(buf);
+                   connection_fatal("%s", buf);
                    ssh_state = SSH_STATE_CLOSED;
                    crReturnV;
                }
@@ -5138,6 +5251,23 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
                        ssh2_pkt_send();
                    }
                }
+           } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
+               char *type;
+               int typelen, want_reply;
+
+               ssh2_pkt_getstring(&type, &typelen);
+               want_reply = ssh2_pkt_getbool();
+
+                /*
+                 * We currently don't support any global requests
+                 * at all, so we either ignore the request or
+                 * respond with REQUEST_FAILURE, depending on
+                 * want_reply.
+                 */
+                if (want_reply) {
+                    ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
+                    ssh2_pkt_send();
+               }
            } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
                char *type;
                int typelen;