+/* $OpenBSD: sshconnect.c,v 1.200 2006/10/10 10:12:45 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
*/
#include "includes.h"
-RCSID("$OpenBSD: sshconnect.c,v 1.171 2005/12/06 22:38:27 reyk Exp $");
-#include <openssl/bn.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <netdb.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
-#include "ssh.h"
#include "xmalloc.h"
+#include "key.h"
+#include "hostfile.h"
+#include "ssh.h"
#include "rsa.h"
#include "buffer.h"
#include "packet.h"
#include "atomicio.h"
#include "misc.h"
#include "dns.h"
+#include "version.h"
char *client_version_string = NULL;
char *server_version_string = NULL;
int pin[2], pout[2];
pid_t pid;
char strport[NI_MAXSERV];
- size_t len;
/* Convert the port number into a string. */
snprintf(strport, sizeof strport, "%hu", port);
* Use "exec" to avoid "sh -c" processes on some platforms
* (e.g. Solaris)
*/
- len = strlen(proxy_command) + 6;
- tmp = xmalloc(len);
- strlcpy(tmp, "exec ", len);
- strlcat(tmp, proxy_command, len);
+ xasprintf(&tmp, "exec %s", proxy_command);
command_string = percent_expand(tmp, "h", host,
"p", strport, (char *)NULL);
xfree(tmp);
char *argv[10];
/* Child. Permanently give up superuser privileges. */
- seteuid(original_real_uid);
- setuid(original_real_uid);
+ permanently_drop_suid(original_real_uid);
/* Redirect stdin and stdout. */
close(pin[1]);
return 0;
}
+/*
+ * Set TCP receive buffer if requested.
+ * Note: tuning needs to happen after the socket is
+ * created but before the connection happens
+ * so winscale is negotiated properly -cjr
+ */
+static void
+ssh_set_socket_recvbuf(int sock)
+{
+ void *buf = (void *)&options.tcp_rcv_buf;
+ int sz = sizeof(options.tcp_rcv_buf);
+ int socksize;
+ int socksizelen = sizeof(int);
+
+ debug("setsockopt Attempting to set SO_RCVBUF to %d", options.tcp_rcv_buf);
+ if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF, buf, sz) >= 0) {
+ getsockopt(sock, SOL_SOCKET, SO_RCVBUF, &socksize, &socksizelen);
+ debug("setsockopt SO_RCVBUF: %.100s %d", strerror(errno), socksize);
+ }
+ else
+ error("Couldn't set socket receive buffer to %d: %.100s",
+ options.tcp_rcv_buf, strerror(errno));
+}
+
+
/*
* Creates a (possibly privileged) socket for use as the ssh connection.
*/
else
debug("Allocated local port %d.", p);
-
- /* tuning needs to happen after the socket is */
- /* created but before the connection happens */
- /* so winscale is negotiated properly -cjr */
-
- /* Set tcp receive buffer if requested */
- if (options.tcp_rcv_buf)
- {
- if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
- (void *)&options.tcp_rcv_buf,
- sizeof(options.tcp_rcv_buf)) >= 0)
- {
- debug("setsockopt SO_RCVBUF: %.100s", strerror(errno));
- }
- else
- {
- /* coudln't set the socket size to use spec. */
- /* should default to system param and continue */
- /* warn the user though - cjr */
- error("Couldn't set socket receive buffer as requested. Continuing anyway.");
- }
- }
+ if (options.tcp_rcv_buf > 0)
+ ssh_set_socket_recvbuf(sock);
return sock;
}
sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (sock < 0)
error("socket: %.100s", strerror(errno));
- /* tuning needs to happen after the socket is */
- /* created but before the connection happens */
- /* so winscale is negotiated properly -cjr */
-
- /* Set tcp receive buffer if requested */
- if (options.tcp_rcv_buf)
- {
- if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
- (void *)&options.tcp_rcv_buf,
- sizeof(options.tcp_rcv_buf)) >= 0)
- {
- debug("setsockopt SO_RCVBUF: %.100s", strerror(errno));
- }
- else
- {
- /* coudln't set the socket size to use spec. */
- /* should default to system param and continue */
- /* warn the user though - cjr */
- error("Couldn't set socket receive buffer as requested. Continuing anyway.");
- }
- }
-
- /* Bind the socket to an alternative local IP address */
+ if (options.tcp_rcv_buf > 0)
+ ssh_set_socket_recvbuf(sock);
+
+ /* Bind the socket to an alternative local IP address */
if (options.bind_address == NULL)
return sock;
fd_set *fdset;
struct timeval tv;
socklen_t optlen;
- int fdsetsz, optval, rc, result = -1;
+ int optval, rc, result = -1;
if (timeout <= 0)
return (connect(sockfd, serv_addr, addrlen));
if (errno != EINPROGRESS)
return (-1);
- fdsetsz = howmany(sockfd + 1, NFDBITS) * sizeof(fd_mask);
- fdset = (fd_set *)xmalloc(fdsetsz);
-
- memset(fdset, 0, fdsetsz);
+ fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
+ sizeof(fd_mask));
FD_SET(sockfd, fdset);
tv.tv_sec = timeout;
tv.tv_usec = 0;
fatal("%s: %.100s: %s", __progname, host,
gai_strerror(gaierr));
- /*
- * Try to connect several times. On some machines, the first time
- * will sometimes fail. In general socket code appears to behave
- * quite magically on many machines.
- */
- for (attempt = 0; ;) {
- if (attempt > 0)
+ for (attempt = 0; attempt < connection_attempts; attempt++) {
+ if (attempt > 0) {
+ /* Sleep a moment before retrying. */
+ sleep(1);
debug("Trying again...");
-
- /* Loop through addresses for this host, and try each one in
- sequence until the connection succeeds. */
+ }
+ /*
+ * Loop through addresses for this host, and try each one in
+ * sequence until the connection succeeds.
+ */
for (ai = aitop; ai; ai = ai->ai_next) {
if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
continue;
} else {
debug("connect to address %s port %s: %s",
ntop, strport, strerror(errno));
- /*
- * Close the failed socket; there appear to
- * be some problems when reusing a socket for
- * which connect() has already returned an
- * error.
- */
close(sock);
+ sock = -1;
}
}
- if (ai)
+ if (sock != -1)
break; /* Successful connection. */
-
- attempt++;
- if (attempt >= connection_attempts)
- break;
- /* Sleep a moment before retrying. */
- sleep(1);
}
freeaddrinfo(aitop);
/* Return failure if we didn't get a successful connection. */
- if (attempt >= connection_attempts) {
+ if (sock == -1) {
error("ssh: connect to host %s port %s: %s",
host, strport, strerror(errno));
return (-1);
int connection_in = packet_get_connection_in();
int connection_out = packet_get_connection_out();
int minor1 = PROTOCOL_MINOR_1;
- u_int i;
+ u_int i, n;
/* Read other side's version identification. */
- for (;;) {
+ for (n = 0;;) {
for (i = 0; i < sizeof(buf) - 1; i++) {
size_t len = atomicio(read, connection_in, &buf[i], 1);
buf[i + 1] = 0;
break;
}
+ if (++n > 65536)
+ fatal("ssh_exchange_identification: No banner received");
}
buf[sizeof(buf) - 1] = 0;
if (strncmp(buf, "SSH-", 4) == 0)
* check whether the supplied host key is valid, return -1 if the key
* is not valid. the user_hostfile will not be updated if 'readonly' is true.
*/
+#define RDRW 0
+#define RDONLY 1
+#define ROQUIET 2
static int
-check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
- int readonly, const char *user_hostfile, const char *system_hostfile)
+check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
+ Key *host_key, int readonly, const char *user_hostfile,
+ const char *system_hostfile)
{
Key *file_key;
const char *type = key_type(host_key);
- char *ip = NULL;
+ char *ip = NULL, *host = NULL;
char hostline[1000], *hostp, *fp;
HostStatus host_status;
HostStatus ip_status;
if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop),
NULL, 0, NI_NUMERICHOST) != 0)
fatal("check_host_key: getnameinfo failed");
- ip = xstrdup(ntop);
+ ip = put_host_port(ntop, port);
} else {
ip = xstrdup("<no hostip for proxy command>");
}
* Turn off check_host_ip if the connection is to localhost, via proxy
* command or if we don't have a hostname to compare with
*/
- if (options.check_host_ip &&
- (local || strcmp(host, ip) == 0 || options.proxy_command != NULL))
+ if (options.check_host_ip && (local ||
+ strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
options.check_host_ip = 0;
/*
- * Allow the user to record the key under a different name. This is
- * useful for ssh tunneling over forwarded connections or if you run
- * multiple sshd's on different ports on the same machine.
+ * Allow the user to record the key under a different name or
+ * differentiate a non-standard port. This is useful for ssh
+ * tunneling over forwarded connections or if you run multiple
+ * sshd's on different ports on the same machine.
*/
if (options.host_key_alias != NULL) {
- host = options.host_key_alias;
+ host = xstrdup(options.host_key_alias);
debug("using hostkeyalias: %s", host);
+ } else {
+ host = put_host_port(hostname, port);
}
/*
}
break;
case HOST_NEW:
+ if (options.host_key_alias == NULL && port != 0 &&
+ port != SSH_DEFAULT_PORT) {
+ debug("checking without port identifier");
+ if (check_host_key(hostname, hostaddr, 0, host_key, 2,
+ user_hostfile, system_hostfile) == 0) {
+ debug("found matching key w/out port");
+ break;
+ }
+ }
if (readonly)
goto fail;
/* The host is new. */
"list of known hosts.", hostp, type);
break;
case HOST_CHANGED:
+ if (readonly == ROQUIET)
+ goto fail;
if (options.check_host_ip && host_ip_differ) {
char *key_msg;
if (ip_status == HOST_NEW)
/*
* If strict host key checking has not been requested, allow
* the connection but without MITM-able authentication or
- * agent forwarding.
+ * forwarding.
*/
if (options.password_authentication) {
error("Password authentication is disabled to avoid "
options.num_local_forwards =
options.num_remote_forwards = 0;
}
+ if (options.tun_open != SSH_TUNMODE_NO) {
+ error("Tunnel forwarding is disabled to avoid "
+ "man-in-the-middle attacks.");
+ options.tun_open = SSH_TUNMODE_NO;
+ }
/*
* XXX Should permit the user to change to use the new id.
* This could be done by converting the host key to an
}
xfree(ip);
+ xfree(host);
return 0;
fail:
xfree(ip);
+ xfree(host);
return -1;
}
/* return ok if the key can be found in an old keyfile */
if (stat(options.system_hostfile2, &st) == 0 ||
stat(options.user_hostfile2, &st) == 0) {
- if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1,
- options.user_hostfile2, options.system_hostfile2) == 0)
+ if (check_host_key(host, hostaddr, options.port, host_key,
+ RDONLY, options.user_hostfile2,
+ options.system_hostfile2) == 0)
return 0;
}
- return check_host_key(host, hostaddr, host_key, /*readonly*/ 0,
- options.user_hostfile, options.system_hostfile);
+ return check_host_key(host, hostaddr, options.port, host_key,
+ RDRW, options.user_hostfile, options.system_hostfile);
}
/*
host = xstrdup(orighost);
for (cp = host; *cp; cp++)
if (isupper(*cp))
- *cp = tolower(*cp);
+ *cp = (char)tolower(*cp);
/* Exchange protocol version identification strings with the server. */
ssh_exchange_identification();
ssh_kex(host, hostaddr);
ssh_userauth1(local_user, server_user, host, sensitive);
}
+ xfree(local_user);
}
void
return;
}
size = roundup(strlen(password) + 1, 32);
- padded = xmalloc(size);
- memset(padded, 0, size);
+ padded = xcalloc(1, size);
strlcpy(padded, password, size);
packet_put_string(padded, size);
memset(padded, 0, size);
andersk / gssapi-openssh.git / blobdiff