Hack to work around the rootshell.com xterm DoS problem. A better

[u/mdw/putty] / ssh.c

diff --git a/ssh.c b/ssh.c
index d31d823..295d0e6 100644 (file)
--- a/ssh.c
+++ b/ssh.c
@@ -127,6 +127,7 @@ static void ssh_gotdata(unsigned char *data, int datalen) {
     static long len, biglen, to_read;
     static unsigned char *p;
     static int i, pad;
+    static unsigned long realcrc, gotcrc;
 
     crBegin;
     while (1) {
@@ -152,8 +153,15 @@ static void ssh_gotdata(unsigned char *data, int datalen) {
        pktin.length = len;
        if (pktin.maxlen < biglen) {
            pktin.maxlen = biglen;
+#ifdef MSCRYPTOAPI
+           /* Allocate enough buffer space for extra block
+            * for MS CryptEncrypt() */
+           pktin.data = (pktin.data == NULL ? malloc(biglen+8) :
+                         realloc(pktin.data, biglen+8));
+#else
            pktin.data = (pktin.data == NULL ? malloc(biglen) :
-                       realloc(pktin.data, biglen));
+                         realloc(pktin.data, biglen));
+#endif
            if (!pktin.data)
                fatalbox("Out of memory");
        }
@@ -179,6 +187,15 @@ static void ssh_gotdata(unsigned char *data, int datalen) {
        pktin.type = pktin.data[pad];
        pktin.body = pktin.data+pad+1;
 
+       realcrc = crc32(pktin.data, biglen-4);
+       gotcrc = (pktin.data[biglen-4] << 24);
+       gotcrc |= (pktin.data[biglen-3] << 16);
+       gotcrc |= (pktin.data[biglen-2] <<  8);
+       gotcrc |= (pktin.data[biglen-1] <<  0);
+       if (gotcrc != realcrc) {
+           fatalbox("Incorrect CRC received on packet");
+       }
+
        if (pktin.type == SSH_MSG_DEBUG) {
            /* FIXME: log it */
        } else if (pktin.type == SSH_MSG_IGNORE) {
@@ -199,8 +216,15 @@ static void s_wrpkt_start(int type, int len) {
     pktout.length = len-5;
     if (pktout.maxlen < biglen) {
        pktout.maxlen = biglen;
+#ifdef MSCRYPTOAPI
+       /* Allocate enough buffer space for extra block 
+        * for MS CryptEncrypt() */
+       pktout.data = (pktout.data == NULL ? malloc(biglen+8) :
+                      realloc(pktout.data, biglen+8));
+#else
        pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
                       realloc(pktout.data, biglen+4));
+#endif
        if (!pktout.data)
            fatalbox("Out of memory");
     }
@@ -486,7 +510,8 @@ static void ssh_protocol(unsigned char *in, int inlen, int ispkt) {
                    exit(0);
                    break;
                  default:
-                   if (c >= ' ' && c <= '~' && pos < 40) {
+                   if (((c >= ' ' && c <= '~') ||
+                         ((unsigned char)c >= 160)) && pos < 40) {
                        username[pos++] = c;
                        c_write(&c, 1);
                    }
@@ -570,7 +595,8 @@ static void ssh_protocol(unsigned char *in, int inlen, int ispkt) {
                exit(0);
                break;
              default:
-               if (c >= ' ' && c <= '~' && pos < 40)
+               if (((c >= ' ' && c <= '~') ||
+                     ((unsigned char)c >= 160)) && pos < 40)
                    password[pos++] = c;
                break;
            }
@@ -685,6 +711,11 @@ static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
     char *FWhost;
     int FWport;
 #endif
+       
+#ifdef MSCRYPTOAPI
+    if(crypto_startup() == 0)
+       return "Microsoft high encryption pack not installed!";
+#endif
 
     savedhost = malloc(1+strlen(host));
     if (!savedhost)