version 1.79, 2000/09/17 15:52:51 |
version 1.79.2.6, 2001/11/15 00:15:00 |
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RCSID("$OpenBSD$"); |
RCSID("$OpenBSD$"); |
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#include <openssl/bn.h> |
#include <openssl/bn.h> |
#include <openssl/dsa.h> |
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#include <openssl/rsa.h> |
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#include "ssh.h" |
#include "xmalloc.h" |
#include "xmalloc.h" |
#include "rsa.h" |
#include "rsa.h" |
#include "ssh.h" |
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#include "buffer.h" |
#include "buffer.h" |
#include "packet.h" |
#include "packet.h" |
#include "uidswap.h" |
#include "uidswap.h" |
#include "compat.h" |
#include "compat.h" |
#include "readconf.h" |
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#include "key.h" |
#include "key.h" |
#include "sshconnect.h" |
#include "sshconnect.h" |
#include "hostfile.h" |
#include "hostfile.h" |
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#include "log.h" |
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#include "readconf.h" |
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#include "atomicio.h" |
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#include "misc.h" |
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char *client_version_string = NULL; |
char *client_version_string = NULL; |
char *server_version_string = NULL; |
char *server_version_string = NULL; |
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extern Options options; |
extern Options options; |
extern char *__progname; |
extern char *__progname; |
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static const char * |
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sockaddr_ntop(struct sockaddr *sa) |
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{ |
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void *addr; |
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static char addrbuf[INET6_ADDRSTRLEN]; |
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switch (sa->sa_family) { |
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case AF_INET: |
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addr = &((struct sockaddr_in *)sa)->sin_addr; |
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break; |
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case AF_INET6: |
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addr = &((struct sockaddr_in6 *)sa)->sin6_addr; |
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break; |
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default: |
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/* This case should be protected against elsewhere */ |
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abort(); |
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} |
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inet_ntop(sa->sa_family, addr, addrbuf, sizeof(addrbuf)); |
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return addrbuf; |
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} |
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/* |
/* |
* Connect to the given ssh server using a proxy command. |
* Connect to the given ssh server using a proxy command. |
*/ |
*/ |
int |
static int |
ssh_proxy_connect(const char *host, u_short port, uid_t original_real_uid, |
ssh_proxy_connect(const char *host, u_short port, struct passwd *pw, |
const char *proxy_command) |
const char *proxy_command) |
{ |
{ |
Buffer command; |
Buffer command; |
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char *argv[10]; |
char *argv[10]; |
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/* Child. Permanently give up superuser privileges. */ |
/* Child. Permanently give up superuser privileges. */ |
permanently_set_uid(original_real_uid); |
permanently_set_uid(pw); |
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/* Redirect stdin and stdout. */ |
/* Redirect stdin and stdout. */ |
close(pin[1]); |
close(pin[1]); |
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/* Stderr is left as it is so that error messages get |
/* Stderr is left as it is so that error messages get |
printed on the user's terminal. */ |
printed on the user's terminal. */ |
argv[0] = "/bin/sh"; |
argv[0] = _PATH_BSHELL; |
argv[1] = "-c"; |
argv[1] = "-c"; |
argv[2] = command_string; |
argv[2] = command_string; |
argv[3] = NULL; |
argv[3] = NULL; |
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/* Execute the proxy command. Note that we gave up any |
/* Execute the proxy command. Note that we gave up any |
extra privileges above. */ |
extra privileges above. */ |
execv("/bin/sh", argv); |
execv(argv[0], argv); |
perror("/bin/sh"); |
perror(argv[0]); |
exit(1); |
exit(1); |
} |
} |
/* Parent. */ |
/* Parent. */ |
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/* Set the connection file descriptors. */ |
/* Set the connection file descriptors. */ |
packet_set_connection(pout[0], pin[1]); |
packet_set_connection(pout[0], pin[1]); |
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return 1; |
/* Indicate OK return */ |
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return 0; |
} |
} |
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/* |
/* |
* Creates a (possibly privileged) socket for use as the ssh connection. |
* Creates a (possibly privileged) socket for use as the ssh connection. |
*/ |
*/ |
int |
static int |
ssh_create_socket(uid_t original_real_uid, int privileged, int family) |
ssh_create_socket(struct passwd *pw, int privileged, int family) |
{ |
{ |
int sock; |
int sock, gaierr; |
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struct addrinfo hints, *res; |
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/* |
/* |
* If we are running as root and want to connect to a privileged |
* If we are running as root and want to connect to a privileged |
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error("rresvport: af=%d %.100s", family, strerror(errno)); |
error("rresvport: af=%d %.100s", family, strerror(errno)); |
else |
else |
debug("Allocated local port %d.", p); |
debug("Allocated local port %d.", p); |
} else { |
return sock; |
/* |
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* Just create an ordinary socket on arbitrary port. We use |
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* the user's uid to create the socket. |
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*/ |
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temporarily_use_uid(original_real_uid); |
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sock = socket(family, SOCK_STREAM, 0); |
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if (sock < 0) |
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error("socket: %.100s", strerror(errno)); |
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restore_uid(); |
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} |
} |
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/* |
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* Just create an ordinary socket on arbitrary port. We use |
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* the user's uid to create the socket. |
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*/ |
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temporarily_use_uid(pw); |
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sock = socket(family, SOCK_STREAM, 0); |
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if (sock < 0) |
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error("socket: %.100s", strerror(errno)); |
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restore_uid(); |
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/* Bind the socket to an alternative local IP address */ |
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if (options.bind_address == NULL) |
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return sock; |
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memset(&hints, 0, sizeof(hints)); |
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hints.ai_family = family; |
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hints.ai_socktype = SOCK_STREAM; |
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hints.ai_flags = AI_PASSIVE; |
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gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); |
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if (gaierr) { |
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error("getaddrinfo: %s: %s", options.bind_address, |
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gai_strerror(gaierr)); |
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close(sock); |
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return -1; |
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} |
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if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { |
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error("bind: %s: %s", options.bind_address, strerror(errno)); |
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close(sock); |
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freeaddrinfo(res); |
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return -1; |
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} |
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freeaddrinfo(res); |
return sock; |
return sock; |
} |
} |
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* second). If proxy_command is non-NULL, it specifies the command (with %h |
* 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 |
* and %p substituted for host and port, respectively) to use to contact |
* the daemon. |
* the daemon. |
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* Return values: |
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* 0 for OK |
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* ECONNREFUSED if we got a "Connection Refused" by the peer on any address |
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* ECONNABORTED if we failed without a "Connection refused" |
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* Suitable error messages for the connection failure will already have been |
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* printed. |
*/ |
*/ |
int |
int |
ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
u_short port, int connection_attempts, |
u_short port, int family, int connection_attempts, |
int anonymous, uid_t original_real_uid, |
int anonymous, struct passwd *pw, const char *proxy_command) |
const char *proxy_command) |
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{ |
{ |
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int gaierr; |
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int on = 1; |
int sock = -1, attempt; |
int sock = -1, attempt; |
struct servent *sp; |
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struct addrinfo hints, *ai, *aitop; |
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char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
int gaierr; |
struct addrinfo hints, *ai, *aitop; |
struct linger linger; |
struct linger linger; |
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struct servent *sp; |
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/* |
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* Did we get only other errors than "Connection refused" (which |
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* should block fallback to rsh and similar), or did we get at least |
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* one "Connection refused"? |
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*/ |
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int full_failure = 1; |
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debug("ssh_connect: getuid %u geteuid %u anon %d", |
debug("ssh_connect: getuid %u geteuid %u anon %d", |
(u_int) getuid(), (u_int) geteuid(), anonymous); |
(u_int) getuid(), (u_int) geteuid(), anonymous); |
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} |
} |
/* If a proxy command is given, connect using it. */ |
/* If a proxy command is given, connect using it. */ |
if (proxy_command != NULL) |
if (proxy_command != NULL) |
return ssh_proxy_connect(host, port, original_real_uid, proxy_command); |
return ssh_proxy_connect(host, port, pw, proxy_command); |
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/* No proxy command. */ |
/* No proxy command. */ |
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memset(&hints, 0, sizeof(hints)); |
memset(&hints, 0, sizeof(hints)); |
hints.ai_family = IPv4or6; |
hints.ai_family = family; |
hints.ai_socktype = SOCK_STREAM; |
hints.ai_socktype = SOCK_STREAM; |
snprintf(strport, sizeof strport, "%d", port); |
snprintf(strport, sizeof strport, "%d", port); |
if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
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* Try to connect several times. On some machines, the first time |
* Try to connect several times. On some machines, the first time |
* will sometimes fail. In general socket code appears to behave |
* will sometimes fail. In general socket code appears to behave |
* quite magically on many machines. |
* quite magically on many machines. |
*/ |
*/ |
for (attempt = 0; attempt < connection_attempts; attempt++) { |
for (attempt = 0; ;) { |
if (attempt > 0) |
if (attempt > 0) |
debug("Trying again..."); |
debug("Trying again..."); |
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host, ntop, strport); |
host, ntop, strport); |
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/* Create a socket for connecting. */ |
/* Create a socket for connecting. */ |
sock = ssh_create_socket(original_real_uid, |
sock = ssh_create_socket(pw, |
!anonymous && geteuid() == 0 && port < IPPORT_RESERVED, |
!anonymous && geteuid() == 0, |
ai->ai_family); |
ai->ai_family); |
if (sock < 0) |
if (sock < 0) |
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/* Any error is already output */ |
continue; |
continue; |
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/* Connect to the host. We use the user's uid in the |
/* Connect to the host. We use the user's uid in the |
* hope that it will help with tcp_wrappers showing |
* hope that it will help with tcp_wrappers showing |
* the remote uid as root. |
* 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) { |
if (connect(sock, ai->ai_addr, ai->ai_addrlen) >= 0) { |
/* Successful connection. */ |
/* Successful connection. */ |
memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
restore_uid(); |
restore_uid(); |
break; |
break; |
} else { |
} else { |
debug("connect: %.100s", strerror(errno)); |
if (errno == ECONNREFUSED) |
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full_failure = 0; |
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log("ssh: connect to address %s port %s: %s", |
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sockaddr_ntop(ai->ai_addr), strport, |
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strerror(errno)); |
restore_uid(); |
restore_uid(); |
/* |
/* |
* Close the failed socket; there appear to |
* Close the failed socket; there appear to |
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if (ai) |
if (ai) |
break; /* Successful connection. */ |
break; /* Successful connection. */ |
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attempt++; |
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if (attempt >= connection_attempts) |
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break; |
/* Sleep a moment before retrying. */ |
/* Sleep a moment before retrying. */ |
sleep(1); |
sleep(1); |
} |
} |
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/* Return failure if we didn't get a successful connection. */ |
/* Return failure if we didn't get a successful connection. */ |
if (attempt >= connection_attempts) |
if (attempt >= connection_attempts) |
return 0; |
return full_failure ? ECONNABORTED : ECONNREFUSED; |
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debug("Connection established."); |
debug("Connection established."); |
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/* setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */ |
/* setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */ |
linger.l_onoff = 1; |
linger.l_onoff = 1; |
linger.l_linger = 5; |
linger.l_linger = 5; |
setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *) &linger, sizeof(linger)); |
setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger)); |
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/* Set keepalives if requested. */ |
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if (options.keepalives && |
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setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
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sizeof(on)) < 0) |
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error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
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/* Set the connection. */ |
/* Set the connection. */ |
packet_set_connection(sock, sock); |
packet_set_connection(sock, sock); |
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return 1; |
return 0; |
} |
} |
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/* |
/* |
* Waits for the server identification string, and sends our own |
* Waits for the server identification string, and sends our own |
* identification string. |
* identification string. |
*/ |
*/ |
void |
static void |
ssh_exchange_identification() |
ssh_exchange_identification(void) |
{ |
{ |
char buf[256], remote_version[256]; /* must be same size! */ |
char buf[256], remote_version[256]; /* must be same size! */ |
int remote_major, remote_minor, i, mismatch; |
int remote_major, remote_minor, i, mismatch; |
int connection_in = packet_get_connection_in(); |
int connection_in = packet_get_connection_in(); |
int connection_out = packet_get_connection_out(); |
int connection_out = packet_get_connection_out(); |
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int minor1 = PROTOCOL_MINOR_1; |
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/* Read other side\'s version identification. */ |
/* Read other side\'s version identification. */ |
for (;;) { |
for (;;) { |
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} |
} |
if (remote_minor < 3) { |
if (remote_minor < 3) { |
fatal("Remote machine has too old SSH software version."); |
fatal("Remote machine has too old SSH software version."); |
} else if (remote_minor == 3) { |
} else if (remote_minor == 3 || remote_minor == 4) { |
/* We speak 1.3, too. */ |
/* We speak 1.3, too. */ |
enable_compat13(); |
enable_compat13(); |
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minor1 = 3; |
if (options.forward_agent) { |
if (options.forward_agent) { |
log("Agent forwarding disabled for protocol 1.3"); |
log("Agent forwarding disabled for protocol 1.3"); |
options.forward_agent = 0; |
options.forward_agent = 0; |
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fatal("Protocol major versions differ: %d vs. %d", |
fatal("Protocol major versions differ: %d vs. %d", |
(options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
(options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
remote_major); |
remote_major); |
if (compat20) |
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packet_set_ssh2_format(); |
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/* Send our own protocol version identification. */ |
/* Send our own protocol version identification. */ |
snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", |
snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", |
compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
compat20 ? PROTOCOL_MINOR_2 : PROTOCOL_MINOR_1, |
compat20 ? PROTOCOL_MINOR_2 : minor1, |
SSH_VERSION); |
SSH_VERSION); |
if (atomicio(write, connection_out, buf, strlen(buf)) != strlen(buf)) |
if (atomicio(write, connection_out, buf, strlen(buf)) != strlen(buf)) |
fatal("write: %.100s", strerror(errno)); |
fatal("write: %.100s", strerror(errno)); |
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debug("Local version string %.100s", client_version_string); |
debug("Local version string %.100s", client_version_string); |
} |
} |
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int |
/* defaults to 'no' */ |
read_yes_or_no(const char *prompt, int defval) |
static int |
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confirm(const char *prompt) |
{ |
{ |
char buf[1024]; |
char buf[1024]; |
FILE *f; |
FILE *f; |
int retval = -1; |
int retval = -1; |
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if (isatty(0)) |
if (options.batch_mode) |
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return 0; |
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if (isatty(STDIN_FILENO)) |
f = stdin; |
f = stdin; |
else |
else |
f = fopen("/dev/tty", "rw"); |
f = fopen(_PATH_TTY, "rw"); |
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if (f == NULL) |
if (f == NULL) |
return 0; |
return 0; |
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fflush(stdout); |
fflush(stdout); |
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fprintf(stderr, "%s", prompt); |
while (1) { |
while (1) { |
fprintf(stderr, "%s", prompt); |
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if (fgets(buf, sizeof(buf), f) == NULL) { |
if (fgets(buf, sizeof(buf), f) == NULL) { |
/* Print a newline (the prompt probably didn\'t have one). */ |
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fprintf(stderr, "\n"); |
fprintf(stderr, "\n"); |
strlcpy(buf, "no", sizeof buf); |
strlcpy(buf, "no", sizeof buf); |
} |
} |
/* Remove newline from response. */ |
/* Remove newline from response. */ |
if (strchr(buf, '\n')) |
if (strchr(buf, '\n')) |
*strchr(buf, '\n') = 0; |
*strchr(buf, '\n') = 0; |
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if (buf[0] == 0) |
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retval = defval; |
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if (strcmp(buf, "yes") == 0) |
if (strcmp(buf, "yes") == 0) |
retval = 1; |
retval = 1; |
else if (strcmp(buf, "no") == 0) |
else if (strcmp(buf, "no") == 0) |
retval = 0; |
retval = 0; |
else |
else |
fprintf(stderr, "Please type 'yes' or 'no'.\n"); |
fprintf(stderr, "Please type 'yes' or 'no': "); |
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if (retval != -1) { |
if (retval != -1) { |
if (f != stdin) |
if (f != stdin) |
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} |
} |
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/* |
/* |
* 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 |
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* is not valid. the user_hostfile will not be updated if 'readonly' is true. |
*/ |
*/ |
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void |
static int |
check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, |
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; |
Key *file_key; |
char *type = key_type(host_key); |
char *type = key_type(host_key); |
char *ip = NULL; |
char *ip = NULL; |
char hostline[1000], *hostp; |
char hostline[1000], *hostp, *fp; |
HostStatus host_status; |
HostStatus host_status; |
HostStatus ip_status; |
HostStatus ip_status; |
int local = 0, host_ip_differ = 0; |
int local = 0, host_ip_differ = 0; |
char ntop[NI_MAXHOST]; |
char ntop[NI_MAXHOST]; |
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int host_line, ip_line; |
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const char *host_file = NULL, *ip_file = NULL; |
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/* |
/* |
* Force accepting of the host key for loopback/localhost. The |
* Force accepting of the host key for loopback/localhost. The |
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/** hostaddr == 0! */ |
/** hostaddr == 0! */ |
switch (hostaddr->sa_family) { |
switch (hostaddr->sa_family) { |
case AF_INET: |
case AF_INET: |
local = (ntohl(((struct sockaddr_in *)hostaddr)->sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
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sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
break; |
break; |
case AF_INET6: |
case AF_INET6: |
local = IN6_IS_ADDR_LOOPBACK(&(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); |
local = IN6_IS_ADDR_LOOPBACK( |
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&(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); |
break; |
break; |
default: |
default: |
local = 0; |
local = 0; |
break; |
break; |
} |
} |
if (local) { |
if (options.no_host_authentication_for_localhost == 1 && local && |
debug("Forcing accepting of host key for loopback/localhost."); |
options.host_key_alias == NULL) { |
return; |
debug("Forcing accepting of host key for " |
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"loopback/localhost."); |
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return 0; |
} |
} |
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/* |
/* |
* Turn off check_host_ip for proxy connects, since |
* We don't have the remote ip-address for connections |
* we don't have the remote ip-address |
* using a proxy command |
*/ |
*/ |
if (options.proxy_command != NULL && options.check_host_ip) |
if (options.proxy_command == NULL) { |
options.check_host_ip = 0; |
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if (options.check_host_ip) { |
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if (getnameinfo(hostaddr, hostaddr->sa_len, ntop, sizeof(ntop), |
if (getnameinfo(hostaddr, hostaddr->sa_len, ntop, sizeof(ntop), |
NULL, 0, NI_NUMERICHOST) != 0) |
NULL, 0, NI_NUMERICHOST) != 0) |
fatal("check_host_key: getnameinfo failed"); |
fatal("check_host_key: getnameinfo failed"); |
ip = xstrdup(ntop); |
ip = xstrdup(ntop); |
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} else { |
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ip = xstrdup("<no hostip for proxy command>"); |
} |
} |
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/* |
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* Turn off check_host_ip if the connection is to localhost, via proxy |
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* command or if we don't have a hostname to compare with |
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*/ |
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if (options.check_host_ip && |
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(local || strcmp(host, ip) == 0 || options.proxy_command != NULL)) |
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options.check_host_ip = 0; |
|
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/* |
/* |
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* Allow the user to record the key under a different name. This is |
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* useful for ssh tunneling over forwarded connections or if you run |
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* multiple sshd's on different ports on the same machine. |
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*/ |
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if (options.host_key_alias != NULL) { |
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host = options.host_key_alias; |
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debug("using hostkeyalias: %s", host); |
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} |
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/* |
* Store the host key from the known host file in here so that we can |
* Store the host key from the known host file in here so that we can |
* compare it with the key for the IP address. |
* compare it with the key for the IP address. |
*/ |
*/ |
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* 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. |
* hosts or in the systemwide list. |
*/ |
*/ |
host_status = check_host_in_hostfile(user_hostfile, host, host_key, file_key); |
host_file = user_hostfile; |
if (host_status == HOST_NEW) |
host_status = check_host_in_hostfile(host_file, host, host_key, |
host_status = check_host_in_hostfile(system_hostfile, host, host_key, file_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); |
|
} |
/* |
/* |
* Also perform check for the ip address, skip the check if we are |
* Also perform check for the ip address, skip the check if we are |
* localhost or the hostname was an ip address to begin with |
* localhost or the hostname was an ip address to begin with |
*/ |
*/ |
if (options.check_host_ip && !local && strcmp(host, ip)) { |
if (options.check_host_ip) { |
Key *ip_key = key_new(host_key->type); |
Key *ip_key = key_new(host_key->type); |
ip_status = check_host_in_hostfile(user_hostfile, ip, host_key, ip_key); |
|
|
|
if (ip_status == HOST_NEW) |
ip_file = user_hostfile; |
ip_status = check_host_in_hostfile(system_hostfile, ip, host_key, ip_key); |
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); |
|
} |
if (host_status == HOST_CHANGED && |
if (host_status == HOST_CHANGED && |
(ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
(ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
host_ip_differ = 1; |
host_ip_differ = 1; |
|
|
/* The host is known and the key matches. */ |
/* The host is known and the key matches. */ |
debug("Host '%.200s' is known and matches the %s host key.", |
debug("Host '%.200s' is known and matches the %s host key.", |
host, type); |
host, type); |
if (options.check_host_ip) { |
debug("Found key in %s:%d", host_file, host_line); |
if (ip_status == HOST_NEW) { |
if (options.check_host_ip && ip_status == HOST_NEW) { |
if (!add_host_to_hostfile(user_hostfile, ip, host_key)) |
if (readonly) |
log("Failed to add the %s host key for IP address '%.30s' to the list of known hosts (%.30s).", |
log("%s host key for IP address " |
type, ip, user_hostfile); |
"'%.128s' not in list of known hosts.", |
else |
type, ip); |
log("Warning: Permanently added the %s host key for IP address '%.30s' to the list of known hosts.", |
else if (!add_host_to_hostfile(user_hostfile, ip, |
type, ip); |
host_key)) |
} else if (ip_status != HOST_OK) |
log("Failed to add the %s host key for IP " |
log("Warning: the %s host key for '%.200s' differs from the key for the IP address '%.30s'", |
"address '%.128s' to the list of known " |
type, host, ip); |
"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; |
break; |
case HOST_NEW: |
case HOST_NEW: |
|
if (readonly) |
|
goto fail; |
/* The host is new. */ |
/* The host is new. */ |
if (options.strict_host_key_checking == 1) { |
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. */ |
* User has requested strict host key checking. We |
fatal("No %s host key is known for %.200s and you have requested strict checking.", type, host); |
* 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) { |
} else if (options.strict_host_key_checking == 2) { |
/* The default */ |
/* The default */ |
char prompt[1024]; |
char prompt[1024]; |
char *fp = key_fingerprint(host_key); |
fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
snprintf(prompt, sizeof(prompt), |
snprintf(prompt, sizeof(prompt), |
"The authenticity of host '%.200s' can't be established.\n" |
"The authenticity of host '%.200s (%s)' can't be " |
|
"established.\n" |
"%s key fingerprint is %s.\n" |
"%s key fingerprint is %s.\n" |
"Are you sure you want to continue connecting (yes/no)? ", |
"Are you sure you want to continue connecting " |
host, type, fp); |
"(yes/no)? ", host, ip, type, fp); |
if (!read_yes_or_no(prompt, -1)) |
xfree(fp); |
fatal("Aborted by user!\n"); |
if (!confirm(prompt)) { |
|
goto fail; |
|
} |
} |
} |
if (options.check_host_ip && ip_status == HOST_NEW && strcmp(host, ip)) { |
if (options.check_host_ip && ip_status == HOST_NEW) { |
snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); |
snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); |
hostp = hostline; |
hostp = hostline; |
} else |
} else |
hostp = host; |
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)) |
if (!add_host_to_hostfile(user_hostfile, hostp, host_key)) |
log("Failed to add the host to the list of known hosts (%.500s).", |
log("Failed to add the host to the list of known " |
user_hostfile); |
"hosts (%.500s).", user_hostfile); |
else |
else |
log("Warning: Permanently added '%.200s' (%s) to the list of known hosts.", |
log("Warning: Permanently added '%.200s' (%s) to the " |
hostp, type); |
"list of known hosts.", hostp, type); |
break; |
break; |
case HOST_CHANGED: |
case HOST_CHANGED: |
if (options.check_host_ip && host_ip_differ) { |
if (options.check_host_ip && host_ip_differ) { |
|
|
error("and the key for the according IP address %s", ip); |
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", msg); |
error("DNS SPOOFING is happening or the IP address for the host"); |
error("DNS SPOOFING is happening or the IP address for the host"); |
error("and its host key have changed at the same time"); |
error("and its host key have changed at the same time."); |
|
if (ip_status != HOST_NEW) |
|
error("Offending key for IP in %s:%d", ip_file, ip_line); |
} |
} |
/* The host key has changed. */ |
/* The host key has changed. */ |
|
fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); |
error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); |
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); |
error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); |
error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); |
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("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, fp); |
error("Please contact your system administrator."); |
error("Please contact your system administrator."); |
error("Add correct host key in %.100s to get rid of this message.", |
error("Add correct host key in %.100s to get rid of this message.", |
user_hostfile); |
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 |
* If strict host key checking is in use, the user will have |
* to edit the key manually and we can only abort. |
* to edit the key manually and we can only abort. |
*/ |
*/ |
if (options.strict_host_key_checking) |
if (options.strict_host_key_checking) { |
fatal("%s host key for %.200s has changed and you have requested strict checking.", type, host); |
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 |
* If strict host key checking has not been requested, allow |
|
|
* agent forwarding. |
* agent forwarding. |
*/ |
*/ |
if (options.password_authentication) { |
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; |
options.password_authentication = 0; |
} |
} |
if (options.forward_agent) { |
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; |
options.forward_agent = 0; |
} |
} |
|
if (options.forward_x11) { |
|
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 " |
|
"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. |
* XXX Should permit the user to change to use the new id. |
* This could be done by converting the host key to an |
* This could be done by converting the host key to an |
|
|
*/ |
*/ |
break; |
break; |
} |
} |
if (options.check_host_ip) |
|
xfree(ip); |
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 '%.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) { |
|
error("Exiting, you have requested strict checking."); |
|
goto fail; |
|
} else if (options.strict_host_key_checking == 2) { |
|
if (!confirm("Are you sure you want " |
|
"to continue connecting (yes/no)? ")) { |
|
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); |
|
} |
|
|
/* |
/* |
* Starts a dialog with the server, and authenticates the current user on the |
* Starts a dialog with the server, and authenticates the current user on the |
* server. This does not need any extra privileges. The basic connection |
* server. This does not need any extra privileges. The basic connection |
|
|
* This function does not require super-user privileges. |
* This function does not require super-user privileges. |
*/ |
*/ |
void |
void |
ssh_login(int host_key_valid, RSA *own_host_key, const char *orighost, |
ssh_login(Key **keys, int nkeys, const char *orighost, |
struct sockaddr *hostaddr, uid_t original_real_uid) |
struct sockaddr *hostaddr, struct passwd *pw) |
{ |
{ |
struct passwd *pw; |
|
char *host, *cp; |
char *host, *cp; |
char *server_user, *local_user; |
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); |
local_user = xstrdup(pw->pw_name); |
server_user = options.user ? options.user : local_user; |
server_user = options.user ? options.user : local_user; |
|
|
|
|
/* authenticate user */ |
/* authenticate user */ |
if (compat20) { |
if (compat20) { |
ssh_kex2(host, hostaddr); |
ssh_kex2(host, hostaddr); |
ssh_userauth2(server_user, host); |
ssh_userauth2(local_user, server_user, host, keys, nkeys); |
} else { |
} else { |
ssh_kex(host, hostaddr); |
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); |
} |
} |