- stevesk@cvs.openbsd.org 2006/08/01 23:36:12

[openssh.git] / ssh-keyscan.c

diff --git a/ssh-keyscan.c b/ssh-keyscan.c
index fdcfc5b3c6d7b4b365b20f717f87bb79fa6d001c..70154084111fe4159ed35ed60c2e1c33cfdfb997 100644 (file)
--- a/ssh-keyscan.c
+++ b/ssh-keyscan.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: ssh-keyscan.c,v 1.72 2006/08/01 23:22:47 stevesk Exp $ */
 /*
  * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
  *
@@ -7,13 +8,24 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh-keyscan.c,v 1.53 2005/04/28 10:17:56 moritz Exp $");
-
+ 
 #include "openbsd-compat/sys-queue.h"
+#include <sys/resource.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
 
 #include <openssl/bn.h>
 
+#include <netdb.h>
+#include <errno.h>
 #include <setjmp.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
 #include "xmalloc.h"
 #include "ssh.h"
 #include "ssh1.h"
@@ -54,7 +66,7 @@ int maxfd;
 
 extern char *__progname;
 fd_set *read_wait;
-size_t read_wait_size;
+size_t read_wait_nfdset;
 int ncon;
 int nonfatal_fatal = 0;
 jmp_buf kexjmp;
@@ -128,7 +140,7 @@ Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
                lb->stream = stdin;
        }
 
-       if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
+       if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
                if (errfun)
                        (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
                xfree(lb);
@@ -166,7 +178,7 @@ Linebuf_lineno(Linebuf * lb)
 static char *
 Linebuf_getline(Linebuf * lb)
 {
-       int n = 0;
+       size_t n = 0;
        void *p;
 
        lb->lineno++;
@@ -350,6 +362,7 @@ keygrab_ssh2(con *c)
        c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
        c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
        c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
+       c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
        c->c_kex->verify_host_key = hostjump;
 
        if (!(j = setjmp(kexjmp))) {
@@ -493,27 +506,36 @@ 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 +565,12 @@ 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 +588,14 @@ 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;
@@ -593,7 +615,6 @@ conread(int s)
                        keyprint(c, keygrab_ssh1(c));
                        confree(s);
                        return;
-                       break;
                default:
                        fatal("conread: invalid status %d", c->c_status);
                        break;
@@ -625,10 +646,10 @@ conloop(void)
        } else
                seltime.tv_sec = seltime.tv_usec = 0;
 
-       r = xmalloc(read_wait_size);
-       memcpy(r, read_wait, read_wait_size);
-       e = xmalloc(read_wait_size);
-       memcpy(e, read_wait, read_wait_size);
+       r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
+       e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
+       memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
+       memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
 
        while (select(maxfd, r, NULL, e, &seltime) == -1 &&
            (errno == EAGAIN || errno == EINTR))
@@ -709,6 +730,9 @@ 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();
 
@@ -792,12 +816,10 @@ main(int argc, char **argv)
                fatal("%s: not enough file descriptors", __progname);
        if (maxfd > fdlim_get(0))
                fdlim_set(maxfd);
-       fdcon = xmalloc(maxfd * sizeof(con));
-       memset(fdcon, 0, maxfd * sizeof(con));
+       fdcon = xcalloc(maxfd, sizeof(con));
 
-       read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
-       read_wait = xmalloc(read_wait_size);
-       memset(read_wait, 0, read_wait_size);
+       read_wait_nfdset = howmany(maxfd, NFDBITS);
+       read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 
        if (fopt_count) {
                Linebuf *lb;