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[u/mdw/putty] / ssh.c
diff --git a/ssh.c b/ssh.c
index fe5b05e..08ff8d9 100644 (file)
--- a/ssh.c
+++ b/ssh.c
 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE   9    /* 0x9 */
 #define SSH2_DISCONNECT_CONNECTION_LOST           10   /* 0xa */
 #define SSH2_DISCONNECT_BY_APPLICATION            11   /* 0xb */
+#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS      12   /* 0xc */
+#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER    13   /* 0xd */
+#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
+#define SSH2_DISCONNECT_ILLEGAL_USER_NAME         15   /* 0xf */
+
+static const char *const ssh2_disconnect_reasons[] = {
+    NULL,
+    "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
+    "SSH_DISCONNECT_PROTOCOL_ERROR",
+    "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
+    "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
+    "SSH_DISCONNECT_MAC_ERROR",
+    "SSH_DISCONNECT_COMPRESSION_ERROR",
+    "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
+    "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
+    "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
+    "SSH_DISCONNECT_CONNECTION_LOST",
+    "SSH_DISCONNECT_BY_APPLICATION",
+    "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
+    "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
+    "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
+    "SSH_DISCONNECT_ILLEGAL_USER_NAME",
+};
 
 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED     1    /* 0x1 */
 #define SSH2_OPEN_CONNECT_FAILED                  2    /* 0x2 */
@@ -510,6 +533,20 @@ next_packet:
        goto next_packet;
     }
 
+    if (pktin.type == SSH1_MSG_DISCONNECT) {
+       /* log reason code in disconnect message */
+       char buf[256];
+       int msglen = GET_32BIT(pktin.body);
+       int nowlen;
+       strcpy(buf, "Remote sent disconnect: ");
+       nowlen = strlen(buf);
+       if (msglen > sizeof(buf)-nowlen-1)
+           msglen = sizeof(buf)-nowlen-1;
+       memcpy(buf+nowlen, pktin.body+4, msglen);
+       buf[nowlen+msglen] = '\0';
+       logevent(buf);
+    }
+
     crFinish(0);
 }
 
@@ -649,6 +686,28 @@ next_packet:
     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);
+       int msglen = GET_32BIT(pktin.data+10);
+       int 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);
+    }
+
     crFinish(0);
 }
 
@@ -928,7 +987,7 @@ static void ssh2_pkt_addstring(char *data) {
 }
 static char *ssh2_mpint_fmt(Bignum b, int *len) {
     unsigned char *p;
-    int i, n = (ssh1_bignum_bitcount(b)+7)/8;
+    int i, n = (bignum_bitcount(b)+7)/8;
     p = smalloc(n + 1);
     if (!p)
         fatalbox("out of memory");
@@ -1128,7 +1187,9 @@ static void ssh_detect_bugs(char *vstring) {
     char *imp;                         /* pointer to implementation part */
     imp = vstring;
     imp += strcspn(imp, "-");
+    if (*imp) imp++;
     imp += strcspn(imp, "-");
+    if (*imp) imp++;
 
     ssh_remote_bugs = 0;
 
@@ -1156,10 +1217,11 @@ static void ssh_detect_bugs(char *vstring) {
 }
 
 static int do_ssh_init(unsigned char c) {
-    static char *vsp;
+    static char vslen;
     static char version[10];
-    static char vstring[80];
-    static char vlog[sizeof(vstring)+20];
+    static char *vstring;
+    static int vstrsize;
+    static char *vlog;
     static int i;
 
     crBegin;
@@ -1179,13 +1241,18 @@ static int do_ssh_init(unsigned char c) {
        crReturn(1);                   /* get another character */
     }
 
+    vstring = smalloc(16);
+    vstrsize = 16;
     strcpy(vstring, "SSH-");
-    vsp = vstring+4;
+    vslen = 4;
     i = 0;
     while (1) {
        crReturn(1);                   /* get another char */
-       if (vsp < vstring+sizeof(vstring)-1)
-           *vsp++ = c;
+       if (vslen >= vstrsize-1) {
+            vstrsize += 16;
+            vstring = srealloc(vstring, vstrsize);
+        }
+        vstring[vslen++] = c;
        if (i >= 0) {
            if (c == '-') {
                version[i] = '\0';
@@ -1200,11 +1267,13 @@ static int do_ssh_init(unsigned char c) {
     ssh_agentfwd_enabled = FALSE;
     rdpkt2_state.incoming_sequence = 0;
 
-    *vsp = 0;
+    vstring[vslen] = 0;
+    vlog = smalloc(20 + vslen);
     sprintf(vlog, "Server version: %s", vstring);
     ssh_detect_bugs(vstring);
     vlog[strcspn(vlog, "\r\n")] = '\0';
     logevent(vlog);
+    sfree(vlog);
 
     /*
      * Server version "1.99" means we can choose whether we use v1
@@ -1214,7 +1283,7 @@ static int do_ssh_init(unsigned char c) {
         /*
          * This is a v2 server. Begin v2 protocol.
          */
-        char verstring[80];
+        char verstring[80], vlog[100];
         sprintf(verstring, "SSH-2.0-%s", sshver);
         SHA_Init(&exhashbase);
         /*
@@ -1222,11 +1291,11 @@ static int do_ssh_init(unsigned char c) {
          */
         sha_string(&exhashbase, verstring, strlen(verstring));
         sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
-        sprintf(vstring, "%s\n", verstring);
         sprintf(vlog, "We claim version: %s", verstring);
         logevent(vlog);
+        strcat(verstring, "\n");
         logevent("Using SSH protocol version 2");
-        sk_write(s, vstring, strlen(vstring));
+        sk_write(s, verstring, strlen(verstring));
         ssh_protocol = ssh2_protocol;
         ssh_version = 2;
         s_rdpkt = ssh2_rdpkt;
@@ -1234,20 +1303,23 @@ static int do_ssh_init(unsigned char c) {
         /*
          * This is a v1 server. Begin v1 protocol.
          */
-        sprintf(vstring, "SSH-%s-%s\n",
+        char verstring[80], vlog[100];
+        sprintf(verstring, "SSH-%s-%s",
                 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
                 sshver);
-        sprintf(vlog, "We claim version: %s", vstring);
-        vlog[strcspn(vlog, "\r\n")] = '\0';
+        sprintf(vlog, "We claim version: %s", verstring);
         logevent(vlog);
+        strcat(verstring, "\n");
         logevent("Using SSH protocol version 1");
-        sk_write(s, vstring, strlen(vstring));
+        sk_write(s, verstring, strlen(verstring));
         ssh_protocol = ssh1_protocol;
         ssh_version = 1;
         s_rdpkt = ssh1_rdpkt;
     }
     ssh_state = SSH_STATE_BEFORE_SIZE;
 
+    sfree(vstring);
+
     crFinish(0);
 }
 
@@ -1497,6 +1569,11 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
     if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
        c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
        cipher_type = SSH_CIPHER_3DES;
+       if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
+           bombout(("Server violates SSH 1 protocol by "
+                    "not supporting 3DES encryption"));
+           crReturn(0);
+       }
     }
     switch (cipher_type) {
       case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
@@ -1676,7 +1753,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
                         PUT_32BIT(agentreq, len);
                         q = agentreq + 4;
                         *q++ = SSH1_AGENTC_RSA_CHALLENGE;
-                        PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
+                        PUT_32BIT(q, bignum_bitcount(key.modulus));
                         q += 4;
                         q += ssh1_write_bignum(q, key.exponent);
                         q += ssh1_write_bignum(q, key.modulus);
@@ -2234,7 +2311,8 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
                 if (c) {
                     int closetype;
                     closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
-                    send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
+                    if (!(c->closes & closetype))
+                        send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
                    if ((c->closes == 0) && (c->type == CHAN_X11)) {
                        logevent("X11 connection closed");
                        assert(c->u.x11.s != NULL);
@@ -2979,9 +3057,19 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
            while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
                 char *banner;
                 int size;
-               ssh2_pkt_getstring(&banner, &size);
-                if (banner)
-                    c_write_untrusted(banner, size);
+                /*
+                 * Don't show the banner if we're operating in
+                 * non-verbose non-interactive mode. (It's probably
+                 * a script, which means nobody will read the
+                 * banner _anyway_, and moreover the printing of
+                 * the banner will screw up processing on the
+                 * output of (say) plink.)
+                 */
+                if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
+                    ssh2_pkt_getstring(&banner, &size);
+                    if (banner)
+                        c_write_untrusted(banner, size);
+                }
                crWaitUntilV(ispkt);
            }
            if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
@@ -2993,6 +3081,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
            if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
                bombout(("Strange packet received during authentication: type %d",
                         pktin.type));
+               crReturnV;
            }
 
            gotit = FALSE;
@@ -3110,9 +3199,11 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
                            continue;
                        }
 
-                       c_write_str("Authenticating with public key \"");
-                       c_write(commentp, commentlen);
-                       c_write_str("\" from agent\r\n");
+                        if (flags & FLAG_VERBOSE) {
+                            c_write_str("Authenticating with public key \"");
+                            c_write(commentp, commentlen);
+                            c_write_str("\" from agent\r\n");
+                        }
 
                        /*
                         * Server is willing to accept the key.