+/* $OpenBSD: sshconnect.c,v 1.199 2006/08/03 03:34:42 deraadt 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 1.155 2003/12/09 21:53:37 markus 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 "readconf.h"
#include "atomicio.h"
#include "misc.h"
-#include "readpass.h"
-
#include "dns.h"
+#include "version.h"
char *client_version_string = NULL;
char *server_version_string = NULL;
-int matching_host_key_dns = 0;
+static int matching_host_key_dns = 0;
/* import */
extern Options options;
static int
ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
{
- Buffer command;
- const char *cp;
- char *command_string;
+ char *command_string, *tmp;
int pin[2], pout[2];
pid_t pid;
char strport[NI_MAXSERV];
* Use "exec" to avoid "sh -c" processes on some platforms
* (e.g. Solaris)
*/
- buffer_init(&command);
- buffer_append(&command, "exec ", 5);
-
- for (cp = proxy_command; *cp; cp++) {
- if (cp[0] == '%' && cp[1] == '%') {
- buffer_append(&command, "%", 1);
- cp++;
- continue;
- }
- if (cp[0] == '%' && cp[1] == 'h') {
- buffer_append(&command, host, strlen(host));
- cp++;
- continue;
- }
- if (cp[0] == '%' && cp[1] == 'p') {
- buffer_append(&command, strport, strlen(strport));
- cp++;
- continue;
- }
- buffer_append(&command, cp, 1);
- }
- buffer_append(&command, "\0", 1);
-
- /* Get the final command string. */
- command_string = buffer_ptr(&command);
+ xasprintf(&tmp, "exec %s", proxy_command);
+ command_string = percent_expand(tmp, "h", host,
+ "p", strport, (char *)NULL);
+ xfree(tmp);
/* Create pipes for communicating with the proxy. */
if (pipe(pin) < 0 || pipe(pout) < 0)
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]);
close(pout[1]);
/* Free the command name. */
- buffer_free(&command);
+ xfree(command_string);
/* Set the connection file descriptors. */
packet_set_connection(pout[0], pin[1]);
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 (fcntl(sockfd, F_SETFL, O_NONBLOCK) < 0)
- return (-1);
-
+ set_nonblock(sockfd);
rc = connect(sockfd, serv_addr, addrlen);
- if (rc == 0)
+ if (rc == 0) {
+ unset_nonblock(sockfd);
return (0);
+ }
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;
- for(;;) {
+ for (;;) {
rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
if (rc != -1 || errno != EINTR)
break;
}
- switch(rc) {
+ switch (rc) {
case 0:
/* Timed out */
errno = ETIMEDOUT;
break;
}
result = 0;
+ unset_nonblock(sockfd);
break;
default:
/* Should not occur */
* second). If proxy_command is non-NULL, it specifies the command (with %h
* and %p substituted for host and port, respectively) to use to contact
* the daemon.
- * Return values:
- * 0 for OK
- * ECONNREFUSED if we got a "Connection Refused" by the peer on any address
- * ECONNABORTED if we failed without a "Connection refused"
- * Suitable error messages for the connection failure will already have been
- * printed.
*/
int
ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
int sock = -1, attempt;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
struct addrinfo hints, *ai, *aitop;
- struct servent *sp;
- /*
- * Did we get only other errors than "Connection refused" (which
- * should block fallback to rsh and similar), or did we get at least
- * one "Connection refused"?
- */
- int full_failure = 1;
debug2("ssh_connect: needpriv %d", needpriv);
- /* Get default port if port has not been set. */
- if (port == 0) {
- sp = getservbyname(SSH_SERVICE_NAME, "tcp");
- if (sp)
- port = ntohs(sp->s_port);
- else
- port = SSH_DEFAULT_PORT;
- }
/* If a proxy command is given, connect using it. */
if (proxy_command != NULL)
return ssh_proxy_connect(host, port, proxy_command);
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; ;) {
+ for (attempt = 0; attempt < connection_attempts; attempt++) {
if (attempt > 0)
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;
memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
break;
} else {
- if (errno == ECONNREFUSED)
- full_failure = 0;
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) {
- logit("ssh: connect to host %s port %s: %s",
+ if (sock == -1) {
+ error("ssh: connect to host %s port %s: %s",
host, strport, strerror(errno));
- return full_failure ? ECONNABORTED : ECONNREFUSED;
+ return (-1);
}
debug("Connection established.");
ssh_exchange_identification(void)
{
char buf[256], remote_version[256]; /* must be same size! */
- int remote_major, remote_minor, i, mismatch;
+ int remote_major, remote_minor, mismatch;
int connection_in = packet_get_connection_in();
int connection_out = packet_get_connection_out();
int minor1 = PROTOCOL_MINOR_1;
+ u_int i, n;
- /* Read other side\'s version identification. */
- for (;;) {
+ /* Read other side's version identification. */
+ for (n = 0;;) {
for (i = 0; i < sizeof(buf) - 1; i++) {
- int len = atomicio(read, connection_in, &buf[i], 1);
- if (len < 0)
- fatal("ssh_exchange_identification: read: %.100s", strerror(errno));
- if (len != 1)
+ size_t len = atomicio(read, connection_in, &buf[i], 1);
+
+ if (len != 1 && errno == EPIPE)
fatal("ssh_exchange_identification: Connection closed by remote host");
+ else if (len != 1)
+ fatal("ssh_exchange_identification: read: %.100s", strerror(errno));
if (buf[i] == '\r') {
buf[i] = '\n';
buf[i + 1] = 0;
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;
- int local = 0, host_ip_differ = 0;
+ int r, local = 0, host_ip_differ = 0;
int salen;
char ntop[NI_MAXHOST];
char msg[1024];
switch (hostaddr->sa_family) {
case AF_INET:
local = (ntohl(((struct sockaddr_in *)hostaddr)->
- sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
+ sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
salen = sizeof(struct sockaddr_in);
break;
case AF_INET6:
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);
}
/*
file_key = key_new(host_key->type);
/*
- * Check if the host key is present in the user\'s list of known
+ * Check if the host key is present in the user's list of known
* hosts or in the systemwide list.
*/
host_file = user_hostfile;
"'%.128s' not in list of known hosts.",
type, ip);
else if (!add_host_to_hostfile(user_hostfile, ip,
- host_key))
+ host_key, options.hash_known_hosts))
logit("Failed to add the %s host key for IP "
"address '%.128s' to the list of known "
"hosts (%.30s).", type, ip, user_hostfile);
}
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. */
if (show_other_keys(host, host_key))
snprintf(msg1, sizeof(msg1),
- "\nbut keys of different type are already"
- " known for this host.");
+ "\nbut keys of different type are already"
+ " known for this host.");
else
snprintf(msg1, sizeof(msg1), ".");
/* The default */
if (!confirm(msg))
goto fail;
}
- if (options.check_host_ip && ip_status == HOST_NEW) {
- snprintf(hostline, sizeof(hostline), "%s,%s", host, ip);
- hostp = hostline;
- } else
- hostp = host;
-
/*
* If not in strict mode, add the key automatically to the
* local known_hosts file.
*/
- if (!add_host_to_hostfile(user_hostfile, hostp, host_key))
+ if (options.check_host_ip && ip_status == HOST_NEW) {
+ snprintf(hostline, sizeof(hostline), "%s,%s",
+ host, ip);
+ hostp = hostline;
+ if (options.hash_known_hosts) {
+ /* Add hash of host and IP separately */
+ r = add_host_to_hostfile(user_hostfile, host,
+ host_key, options.hash_known_hosts) &&
+ add_host_to_hostfile(user_hostfile, ip,
+ host_key, options.hash_known_hosts);
+ } else {
+ /* Add unhashed "host,ip" */
+ r = add_host_to_hostfile(user_hostfile,
+ hostline, host_key,
+ options.hash_known_hosts);
+ }
+ } else {
+ r = add_host_to_hostfile(user_hostfile, host, host_key,
+ options.hash_known_hosts);
+ hostp = host;
+ }
+
+ if (!r)
logit("Failed to add the host to the list of known "
"hosts (%.500s).", user_hostfile);
else
"list of known hosts.", hostp, type);
break;
case HOST_CHANGED:
+ if (readonly == ROQUIET)
+ goto fail;
if (options.check_host_ip && host_ip_differ) {
- char *msg;
+ char *key_msg;
if (ip_status == HOST_NEW)
- msg = "is unknown";
+ key_msg = "is unknown";
else if (ip_status == HOST_OK)
- msg = "is unchanged";
+ key_msg = "is unchanged";
else
- msg = "has a different value";
+ key_msg = "has a different value";
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
error("The %s host key for %s has changed,", type, host);
error("and the key for the according IP address %s", ip);
- error("%s. This could either mean that", msg);
+ error("%s. This could either mean that", key_msg);
error("DNS SPOOFING is happening or the IP address for the host");
error("and its host key have changed at the same time.");
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);
xfree(fp);
}
+
+/*
+ * Execute a local command
+ */
+int
+ssh_local_cmd(const char *args)
+{
+ char *shell;
+ pid_t pid;
+ int status;
+
+ if (!options.permit_local_command ||
+ args == NULL || !*args)
+ return (1);
+
+ if ((shell = getenv("SHELL")) == NULL)
+ shell = _PATH_BSHELL;
+
+ pid = fork();
+ if (pid == 0) {
+ debug3("Executing %s -c \"%s\"", shell, args);
+ execl(shell, shell, "-c", args, (char *)NULL);
+ error("Couldn't execute %s -c \"%s\": %s",
+ shell, args, strerror(errno));
+ _exit(1);
+ } else if (pid == -1)
+ fatal("fork failed: %.100s", strerror(errno));
+ while (waitpid(pid, &status, 0) == -1)
+ if (errno != EINTR)
+ fatal("Couldn't wait for child: %s", strerror(errno));
+
+ if (!WIFEXITED(status))
+ return (1);
+
+ return (WEXITSTATUS(status));
+}
andersk / gssapi-openssh.git / blobdiff