- stevesk@cvs.openbsd.org 2006/02/07 01:18:09

[openssh.git] / ssh-keyscan.c

diff --git a/ssh-keyscan.c b/ssh-keyscan.c
index fdcfc5b3c6d7b4b365b20f717f87bb79fa6d001c..1282a62e03568c430a4fac2d975b7196928e5c66 100644 (file)
--- a/ssh-keyscan.c
+++ b/ssh-keyscan.c
@@ -7,7 +7,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh-keyscan.c,v 1.53 2005/04/28 10:17:56 moritz Exp $");
+RCSID("$OpenBSD: ssh-keyscan.c,v 1.58 2006/02/07 01:18:09 stevesk Exp $");
 
 #include "openbsd-compat/sys-queue.h"
 
@@ -166,7 +166,7 @@ Linebuf_lineno(Linebuf * lb)
 static char *
 Linebuf_getline(Linebuf * lb)
 {
-       int n = 0;
+       size_t n = 0;
        void *p;
 
        lb->lineno++;
@@ -493,27 +493,36 @@ conrecycle(int s)
 static void
 congreet(int s)
 {
-       int remote_major = 0, remote_minor = 0, n = 0;
+       int n = 0, remote_major = 0, remote_minor = 0;
        char buf[256], *cp;
        char remote_version[sizeof buf];
        size_t bufsiz;
        con *c = &fdcon[s];
 
-       bufsiz = sizeof(buf);
-       cp = buf;
-       while (bufsiz-- && (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
-               if (*cp == '\r')
-                       *cp = '\n';
-               cp++;
-       }
-       if (n < 0) {
-               if (errno != ECONNREFUSED)
-                       error("read (%s): %s", c->c_name, strerror(errno));
-               conrecycle(s);
-               return;
+       for (;;) {
+               memset(buf, '\0', sizeof(buf));
+               bufsiz = sizeof(buf);
+               cp = buf;
+               while (bufsiz-- &&
+                   (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
+                       if (*cp == '\r')
+                               *cp = '\n';
+                       cp++;
+               }
+               if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
+                       break;
        }
        if (n == 0) {
-               error("%s: Connection closed by remote host", c->c_name);
+               switch (errno) {
+               case EPIPE:
+                       error("%s: Connection closed by remote host", c->c_name);
+                       break;
+               case ECONNREFUSED:
+                       break;
+               default:
+                       error("read (%s): %s", c->c_name, strerror(errno));
+                       break;
+               }
                conrecycle(s);
                return;
        }
@@ -543,12 +552,12 @@ congreet(int s)
        n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
            c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
            c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
-       if (n == -1 || n >= sizeof buf) {
+       if (n < 0 || (size_t)n >= sizeof(buf)) {
                error("snprintf: buffer too small");
                confree(s);
                return;
        }
-       if (atomicio(vwrite, s, buf, n) != n) {
+       if (atomicio(vwrite, s, buf, n) != (size_t)n) {
                error("write (%s): %s", c->c_name, strerror(errno));
                confree(s);
                return;
@@ -566,14 +575,14 @@ static void
 conread(int s)
 {
        con *c = &fdcon[s];
-       int n;
+       size_t n;
 
        if (c->c_status == CS_CON) {
                congreet(s);
                return;
        }
        n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
-       if (n < 0) {
+       if (n == 0) {
                error("read (%s): %s", c->c_name, strerror(errno));
                confree(s);
                return;
@@ -709,6 +718,9 @@ main(int argc, char **argv)
        seed_rng();
        TAILQ_INIT(&tq);
 
+       /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+       sanitise_stdfd();
+
        if (argc <= 1)
                usage();