*/
#include "includes.h"
-RCSID("$OpenBSD: sshconnect.c,v 1.92 2001/01/30 22:48:52 djm Exp $");
+RCSID("$OpenBSD: sshconnect.c,v 1.111 2001/10/01 21:51:16 markus Exp $");
#include <openssl/bn.h>
/* AF_UNSPEC or AF_INET or AF_INET6 */
extern int IPv4or6;
+#ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */
+#define INET6_ADDRSTRLEN 46
+#endif
+
+static const char *
+sockaddr_ntop(struct sockaddr *sa)
+{
+ void *addr;
+ static char addrbuf[INET6_ADDRSTRLEN];
+
+ switch (sa->sa_family) {
+ case AF_INET:
+ addr = &((struct sockaddr_in *)sa)->sin_addr;
+ break;
+ case AF_INET6:
+ addr = &((struct sockaddr_in6 *)sa)->sin6_addr;
+ break;
+ default:
+ /* This case should be protected against elsewhere */
+ abort();
+ }
+ inet_ntop(sa->sa_family, addr, addrbuf, sizeof(addrbuf));
+ return addrbuf;
+}
+
/*
* Connect to the given ssh server using a proxy command.
*/
-int
-ssh_proxy_connect(const char *host, u_short port, uid_t original_real_uid,
+static int
+ssh_proxy_connect(const char *host, u_short port, struct passwd *pw,
const char *proxy_command)
{
Buffer command;
char *argv[10];
/* Child. Permanently give up superuser privileges. */
- permanently_set_uid(original_real_uid);
+ permanently_set_uid(pw);
/* Redirect stdin and stdout. */
close(pin[1]);
/* Set the connection file descriptors. */
packet_set_connection(pout[0], pin[1]);
- return 1;
+ /* Indicate OK return */
+ return 0;
}
/*
* Creates a (possibly privileged) socket for use as the ssh connection.
*/
-int
-ssh_create_socket(uid_t original_real_uid, int privileged, int family)
+static int
+ssh_create_socket(struct passwd *pw, int privileged, int family)
{
- int sock;
+ int sock, gaierr;
+ struct addrinfo hints, *res;
/*
* If we are running as root and want to connect to a privileged
error("rresvport: af=%d %.100s", family, strerror(errno));
else
debug("Allocated local port %d.", p);
- } else {
- /*
- * Just create an ordinary socket on arbitrary port. We use
- * the user's uid to create the socket.
- */
- temporarily_use_uid(original_real_uid);
- sock = socket(family, SOCK_STREAM, 0);
- if (sock < 0)
- error("socket: %.100s", strerror(errno));
- restore_uid();
+ return sock;
}
+ /*
+ * Just create an ordinary socket on arbitrary port. We use
+ * the user's uid to create the socket.
+ */
+ temporarily_use_uid(pw);
+ sock = socket(family, SOCK_STREAM, 0);
+ if (sock < 0)
+ error("socket: %.100s", strerror(errno));
+ restore_uid();
+
+ /* Bind the socket to an alternative local IP address */
+ if (options.bind_address == NULL)
+ return sock;
+
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = IPv4or6;
+ hints.ai_socktype = SOCK_STREAM;
+ hints.ai_flags = AI_PASSIVE;
+ gaierr = getaddrinfo(options.bind_address, "0", &hints, &res);
+ if (gaierr) {
+ error("getaddrinfo: %s: %s", options.bind_address,
+ gai_strerror(gaierr));
+ close(sock);
+ return -1;
+ }
+ if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
+ error("bind: %s: %s", options.bind_address, strerror(errno));
+ close(sock);
+ freeaddrinfo(res);
+ return -1;
+ }
+ freeaddrinfo(res);
return sock;
}
* 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,
u_short port, int connection_attempts,
- int anonymous, uid_t original_real_uid,
+ int anonymous, struct passwd *pw,
const char *proxy_command)
{
int gaierr;
struct addrinfo hints, *ai, *aitop;
struct linger linger;
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;
debug("ssh_connect: getuid %u geteuid %u anon %d",
(u_int) getuid(), (u_int) geteuid(), anonymous);
}
/* If a proxy command is given, connect using it. */
if (proxy_command != NULL)
- return ssh_proxy_connect(host, port, original_real_uid, proxy_command);
+ return ssh_proxy_connect(host, port, pw, proxy_command);
/* No proxy command. */
* 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; attempt < connection_attempts; attempt++) {
+ */
+ for (attempt = 0; ;) {
if (attempt > 0)
debug("Trying again...");
host, ntop, strport);
/* Create a socket for connecting. */
- sock = ssh_create_socket(original_real_uid,
+ sock = ssh_create_socket(pw,
#ifdef HAVE_CYGWIN
!anonymous,
#else
#endif
ai->ai_family);
if (sock < 0)
+ /* Any error is already output */
continue;
/* Connect to the host. We use the user's uid in the
* hope that it will help with tcp_wrappers showing
* the remote uid as root.
*/
- temporarily_use_uid(original_real_uid);
+ temporarily_use_uid(pw);
if (connect(sock, ai->ai_addr, ai->ai_addrlen) >= 0) {
/* Successful connection. */
memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
restore_uid();
break;
} else {
- debug("connect: %.100s", strerror(errno));
+ if (errno == ECONNREFUSED)
+ full_failure = 0;
+ log("ssh: connect to address %s port %s: %s",
+ sockaddr_ntop(ai->ai_addr), strport,
+ strerror(errno));
restore_uid();
/*
* Close the failed socket; there appear to
if (ai)
break; /* Successful connection. */
+ attempt++;
+ if (attempt >= connection_attempts)
+ break;
/* Sleep a moment before retrying. */
sleep(1);
}
/* Return failure if we didn't get a successful connection. */
if (attempt >= connection_attempts)
- return 0;
+ return full_failure ? ECONNABORTED : ECONNREFUSED;
debug("Connection established.");
/* Set the connection. */
packet_set_connection(sock, sock);
- return 1;
+ return 0;
}
/*
* Waits for the server identification string, and sends our own
* identification string.
*/
-void
-ssh_exchange_identification()
+static void
+ssh_exchange_identification(void)
{
char buf[256], remote_version[256]; /* must be same size! */
int remote_major, remote_minor, i, mismatch;
int connection_in = packet_get_connection_in();
int connection_out = packet_get_connection_out();
- int minor1 = PROTOCOL_MINOR_1;
+ int minor1 = PROTOCOL_MINOR_1;
/* Read other side\'s version identification. */
for (;;) {
fatal("Protocol major versions differ: %d vs. %d",
(options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
remote_major);
- if (compat20)
- packet_set_ssh2_format();
/* Send our own protocol version identification. */
snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n",
compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
debug("Local version string %.100s", client_version_string);
}
-int
+/* defaults to 'no' */
+static int
read_yes_or_no(const char *prompt, int defval)
{
char buf[1024];
FILE *f;
int retval = -1;
+ if (options.batch_mode)
+ return 0;
+
if (isatty(STDIN_FILENO))
f = stdin;
else
- f = fopen("/dev/tty", "rw");
+ f = fopen(_PATH_TTY, "rw");
if (f == NULL)
return 0;
while (1) {
fprintf(stderr, "%s", prompt);
if (fgets(buf, sizeof(buf), f) == NULL) {
- /* Print a newline (the prompt probably didn\'t have one). */
+ /*
+ * Print a newline (the prompt probably didn\'t have
+ * one).
+ */
fprintf(stderr, "\n");
strlcpy(buf, "no", sizeof buf);
}
}
/*
- * check whether the supplied host key is valid, return only if ok.
+ * 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.
*/
-void
+static int
check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
- const char *user_hostfile, const char *system_hostfile)
+ int readonly, const char *user_hostfile, const char *system_hostfile)
{
Key *file_key;
char *type = key_type(host_key);
char *ip = NULL;
- char hostline[1000], *hostp;
+ char hostline[1000], *hostp, *fp;
HostStatus host_status;
HostStatus ip_status;
int local = 0, host_ip_differ = 0;
/** hostaddr == 0! */
switch (hostaddr->sa_family) {
case AF_INET:
- local = (ntohl(((struct sockaddr_in *)hostaddr)->sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
+ local = (ntohl(((struct sockaddr_in *)hostaddr)->
+ sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
salen = sizeof(struct sockaddr_in);
break;
case AF_INET6:
- local = IN6_IS_ADDR_LOOPBACK(&(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
+ local = IN6_IS_ADDR_LOOPBACK(
+ &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
salen = sizeof(struct sockaddr_in6);
break;
default:
salen = sizeof(struct sockaddr_storage);
break;
}
- if (local && options.host_key_alias == NULL) {
+ if (options.no_host_authentication_for_localhost == 1 && local &&
+ options.host_key_alias == NULL) {
debug("Forcing accepting of host key for "
"loopback/localhost.");
- return;
+ return 0;
}
/*
* hosts or in the systemwide list.
*/
host_file = user_hostfile;
- host_status = check_host_in_hostfile(host_file, host, host_key, file_key, &host_line);
+ host_status = check_host_in_hostfile(host_file, host, host_key,
+ file_key, &host_line);
if (host_status == HOST_NEW) {
host_file = system_hostfile;
- host_status = check_host_in_hostfile(host_file, host, host_key, file_key, &host_line);
+ host_status = check_host_in_hostfile(host_file, host, host_key,
+ file_key, &host_line);
}
/*
* Also perform check for the ip address, skip the check if we are
Key *ip_key = key_new(host_key->type);
ip_file = user_hostfile;
- ip_status = check_host_in_hostfile(ip_file, ip, host_key, ip_key, &ip_line);
+ ip_status = check_host_in_hostfile(ip_file, ip, host_key,
+ ip_key, &ip_line);
if (ip_status == HOST_NEW) {
ip_file = system_hostfile;
- ip_status = check_host_in_hostfile(ip_file, ip, host_key, ip_key, &ip_line);
+ ip_status = check_host_in_hostfile(ip_file, ip,
+ host_key, ip_key, &ip_line);
}
if (host_status == HOST_CHANGED &&
(ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
host, type);
debug("Found key in %s:%d", host_file, host_line);
if (options.check_host_ip && ip_status == HOST_NEW) {
- if (!add_host_to_hostfile(user_hostfile, ip, host_key))
- log("Failed to add the %s host key for IP address '%.30s' to the list of known hosts (%.30s).",
- type, ip, user_hostfile);
- else
- log("Warning: Permanently added the %s host key for IP address '%.30s' to the list of known hosts.",
+ if (readonly)
+ log("%s host key for IP address "
+ "'%.128s' not in list of known hosts.",
type, ip);
+ else if (!add_host_to_hostfile(user_hostfile, ip,
+ host_key))
+ log("Failed to add the %s host key for IP "
+ "address '%.128s' to the list of known "
+ "hosts (%.30s).", type, ip, user_hostfile);
+ else
+ log("Warning: Permanently added the %s host "
+ "key for IP address '%.128s' to the list "
+ "of known hosts.", type, ip);
}
break;
case HOST_NEW:
+ if (readonly)
+ goto fail;
/* The host is new. */
if (options.strict_host_key_checking == 1) {
- /* User has requested strict host key checking. We will not add the host key
- automatically. The only alternative left is to abort. */
- fatal("No %s host key is known for %.200s and you have requested strict checking.", type, host);
+ /*
+ * User has requested strict host key checking. We
+ * will not add the host key automatically. The only
+ * alternative left is to abort.
+ */
+ error("No %s host key is known for %.200s and you "
+ "have requested strict checking.", type, host);
+ goto fail;
} else if (options.strict_host_key_checking == 2) {
/* The default */
char prompt[1024];
+ fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
snprintf(prompt, sizeof(prompt),
- "The authenticity of host '%.200s (%s)' can't be established.\n"
+ "The authenticity of host '%.200s (%s)' can't be "
+ "established.\n"
"%s key fingerprint is %s.\n"
- "Are you sure you want to continue connecting (yes/no)? ",
- host, ip, type, key_fingerprint(host_key));
- if (!read_yes_or_no(prompt, -1))
- fatal("Aborted by user!\n");
+ "Are you sure you want to continue connecting "
+ "(yes/no)? ", host, ip, type, fp);
+ xfree(fp);
+ if (!read_yes_or_no(prompt, -1)) {
+ log("Aborted by user!");
+ goto fail;
+ }
}
if (options.check_host_ip && ip_status == HOST_NEW) {
snprintf(hostline, sizeof(hostline), "%s,%s", host, ip);
} else
hostp = host;
- /* If not in strict mode, add the key automatically to the local known_hosts file. */
+ /*
+ * 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))
- log("Failed to add the host to the list of known hosts (%.500s).",
- user_hostfile);
+ log("Failed to add the host to the list of known "
+ "hosts (%.500s).", user_hostfile);
else
- log("Warning: Permanently added '%.200s' (%s) to the list of known hosts.",
- hostp, type);
+ log("Warning: Permanently added '%.200s' (%s) to the "
+ "list of known hosts.", hostp, type);
break;
case HOST_CHANGED:
if (options.check_host_ip && host_ip_differ) {
error("Offending key for IP in %s:%d", ip_file, ip_line);
}
/* The host key has changed. */
+ fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
error("It is also possible that the %s host key has just been changed.", type);
error("The fingerprint for the %s key sent by the remote host is\n%s.",
- type, key_fingerprint(host_key));
+ type, fp);
error("Please contact your system administrator.");
error("Add correct host key in %.100s to get rid of this message.",
user_hostfile);
error("Offending key in %s:%d", host_file, host_line);
+ xfree(fp);
/*
* If strict host key checking is in use, the user will have
* to edit the key manually and we can only abort.
*/
- if (options.strict_host_key_checking)
- fatal("%s host key for %.200s has changed and you have requested strict checking.", type, host);
+ if (options.strict_host_key_checking) {
+ error("%s host key for %.200s has changed and you have "
+ "requested strict checking.", type, host);
+ goto fail;
+ }
/*
* If strict host key checking has not been requested, allow
* agent forwarding.
*/
if (options.password_authentication) {
- error("Password authentication is disabled to avoid trojan horses.");
+ error("Password authentication is disabled to avoid "
+ "man-in-the-middle attacks.");
options.password_authentication = 0;
}
if (options.forward_agent) {
- error("Agent forwarding is disabled to avoid trojan horses.");
+ error("Agent forwarding is disabled to avoid "
+ "man-in-the-middle attacks.");
options.forward_agent = 0;
}
if (options.forward_x11) {
- error("X11 forwarding is disabled to avoid trojan horses.");
+ error("X11 forwarding is disabled to avoid "
+ "man-in-the-middle attacks.");
options.forward_x11 = 0;
}
- if (options.num_local_forwards > 0 || options.num_remote_forwards > 0) {
- error("Port forwarding is disabled to avoid trojan horses.");
- options.num_local_forwards = options.num_remote_forwards = 0;
+ if (options.num_local_forwards > 0 ||
+ options.num_remote_forwards > 0) {
+ error("Port forwarding is disabled to avoid "
+ "man-in-the-middle attacks.");
+ options.num_local_forwards =
+ options.num_remote_forwards = 0;
}
/*
* XXX Should permit the user to change to use the new id.
if (options.check_host_ip && host_status != HOST_CHANGED &&
ip_status == HOST_CHANGED) {
log("Warning: the %s host key for '%.200s' "
- "differs from the key for the IP address '%.30s'",
+ "differs from the key for the IP address '%.128s'",
type, host, ip);
if (host_status == HOST_OK)
log("Matching host key in %s:%d", host_file, host_line);
log("Offending key for IP in %s:%d", ip_file, ip_line);
if (options.strict_host_key_checking == 1) {
- fatal("Exiting, you have requested strict checking.");
+ error("Exiting, you have requested strict checking.");
+ goto fail;
} else if (options.strict_host_key_checking == 2) {
- if (!read_yes_or_no("Are you sure you want " \
- "to continue connecting (yes/no)? ", -1))
- fatal("Aborted by user!\n");
+ if (!read_yes_or_no("Are you sure you want "
+ "to continue connecting (yes/no)? ", -1)) {
+ log("Aborted by user!");
+ goto fail;
+ }
}
}
xfree(ip);
+ return 0;
+
+fail:
+ xfree(ip);
+ return -1;
+}
+
+int
+verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
+{
+ struct stat st;
+
+ /* 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)
+ return 0;
+ }
+ return check_host_key(host, hostaddr, host_key, /*readonly*/ 0,
+ options.user_hostfile, options.system_hostfile);
}
/*
* This function does not require super-user privileges.
*/
void
-ssh_login(int host_key_valid, RSA *own_host_key, const char *orighost,
- struct sockaddr *hostaddr, uid_t original_real_uid)
+ssh_login(Key **keys, int nkeys, const char *orighost,
+ struct sockaddr *hostaddr, struct passwd *pw)
{
- struct passwd *pw;
char *host, *cp;
char *server_user, *local_user;
- /* Get local user name. Use it as server user if no user name was given. */
- pw = getpwuid(original_real_uid);
- if (!pw)
- fatal("User id %u not found from user database.", original_real_uid);
local_user = xstrdup(pw->pw_name);
server_user = options.user ? options.user : local_user;
/* authenticate user */
if (compat20) {
ssh_kex2(host, hostaddr);
- ssh_userauth2(server_user, host);
+ ssh_userauth2(local_user, server_user, host, keys, nkeys);
} else {
ssh_kex(host, hostaddr);
- ssh_userauth(local_user, server_user, host, host_key_valid, own_host_key);
+ ssh_userauth1(local_user, server_user, host, keys, nkeys);
+ }
+}
+
+void
+ssh_put_password(char *password)
+{
+ int size;
+ char *padded;
+
+ if (datafellows & SSH_BUG_PASSWORDPAD) {
+ packet_put_cstring(password);
+ return;
}
+ size = roundup(strlen(password) + 1, 32);
+ padded = xmalloc(size);
+ memset(padded, 0, size);
+ strlcpy(padded, password, size);
+ packet_put_string(padded, size);
+ memset(padded, 0, size);
+ xfree(padded);
}
andersk / openssh.git / blobdiff