*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.135 2000/11/29 21:11:59 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.163 2001/02/04 23:56:23 deraadt Exp $");
+#include <openssl/dh.h>
+#include <openssl/bn.h>
+#include <openssl/hmac.h>
+
+#include "ssh.h"
+#include "ssh1.h"
+#include "ssh2.h"
#include "xmalloc.h"
#include "rsa.h"
-#include "ssh.h"
#include "pty.h"
#include "packet.h"
#include "mpaux.h"
+#include "log.h"
#include "servconf.h"
#include "uidswap.h"
#include "compat.h"
#include "buffer.h"
-
-#include "ssh2.h"
-#include <openssl/dh.h>
-#include <openssl/bn.h>
-#include <openssl/hmac.h>
+#include "cipher.h"
#include "kex.h"
-#include <openssl/dsa.h>
-#include <openssl/rsa.h>
#include "key.h"
#include "dh.h"
-
-#include "auth.h"
#include "myproposal.h"
#include "authfile.h"
+#include "pathnames.h"
+#include "atomicio.h"
+#include "canohost.h"
+#include "auth.h"
+#include "misc.h"
#ifdef LIBWRAP
#include <tcpd.h>
ServerOptions options;
/* Name of the server configuration file. */
-char *config_file_name = SERVER_CONFIG_FILE;
+char *config_file_name = _PATH_SERVER_CONFIG_FILE;
/*
* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
/* debug goes to stderr unless inetd_flag is set */
int log_stderr = 0;
-/* argv[0] without path. */
-char *av0;
-
/* Saved arguments to main(). */
char **saved_argv;
int saved_argc;
} sensitive_data;
/*
- * Flag indicating whether the current session key has been used. This flag
- * is set whenever the key is used, and cleared when the key is regenerated.
+ * Flag indicating whether the RSA server key needs to be regenerated.
+ * Is set in the SIGALRM handler and cleared when the key is regenerated.
*/
-int key_used = 0;
+int key_do_regen = 0;
/* This is set to true when SIGHUP is received. */
int received_sighup = 0;
/* session identifier, used by RSA-auth */
-unsigned char session_id[16];
+u_char session_id[16];
/* same for ssh2 */
-unsigned char *session_id2 = NULL;
+u_char *session_id2 = NULL;
int session_id2_len = 0;
/* record remote hostname or ip */
-unsigned int utmp_len = MAXHOSTNAMELEN;
+u_int utmp_len = MAXHOSTNAMELEN;
/* Prototypes for various functions defined later in this file. */
-void do_ssh1_kex();
-void do_ssh2_kex();
+void do_ssh1_kex(void);
+void do_ssh2_kex(void);
void ssh_dh1_server(Kex *, Buffer *_kexinit, Buffer *);
void ssh_dhgex_server(Kex *, Buffer *_kexinit, Buffer *);
log("Received SIGHUP; restarting.");
close_listen_socks();
execv(saved_argv[0], saved_argv);
- log("RESTART FAILED: av0='%s', error: %s.", av0, strerror(errno));
+ log("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], strerror(errno));
exit(1);
}
* Thus there should be no concurrency control/asynchronous execution
* problems.
*/
-/* XXX do we really want this work to be done in a signal handler ? -m */
void
generate_empheral_server_key(void)
{
arc4random_stir();
log("RSA key generation complete.");
}
+
void
key_regeneration_alarm(int sig)
{
int save_errno = errno;
-
- /* Check if we should generate a new key. */
- if (key_used) {
- /* This should really be done in the background. */
- generate_empheral_server_key();
- key_used = 0;
- }
- /* Reschedule the alarm. */
- signal(SIGALRM, key_regeneration_alarm);
- alarm(options.key_regeneration_time);
+ signal(SIGALRM, SIG_DFL);
errno = save_errno;
+ key_do_regen = 1;
}
void
key_free(sensitive_data.server_key);
sensitive_data.server_key = NULL;
}
- for(i = 0; i < options.num_host_key_files; i++) {
+ for(i = 0; i < options.num_host_key_files; i++) {
if (sensitive_data.host_keys[i]) {
key_free(sensitive_data.host_keys[i]);
sensitive_data.host_keys[i] = NULL;
int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
pid_t pid;
socklen_t fromlen;
- int silent = 0;
fd_set *fdset;
struct sockaddr_storage from;
const char *remote_ip;
int listen_sock, maxfd;
int startup_p[2];
int startups = 0;
+ int ret, key_used = 0;
__progname = get_progname(av[0]);
init_rng();
- /* Save argv[0]. */
+ /* Save argv. */
saved_argc = ac;
saved_argv = av;
- if (strchr(av[0], '/'))
- av0 = strrchr(av[0], '/') + 1;
- else
- av0 = av[0];
/* Initialize configuration options to their default values. */
initialize_server_options(&options);
/* Parse command-line arguments. */
- while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:u:dDiqQ46")) != EOF) {
+ while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:u:dDiqQ46")) != -1) {
switch (opt) {
case '4':
IPv4or6 = AF_INET;
inetd_flag = 1;
break;
case 'Q':
- silent = 1;
+ /* ignored */
break;
case 'q':
options.log_level = SYSLOG_LEVEL_QUIET;
case '?':
default:
fprintf(stderr, "sshd version %s\n", SSH_VERSION);
- fprintf(stderr, "Usage: %s [options]\n", av0);
+ fprintf(stderr, "Usage: %s [options]\n", __progname);
fprintf(stderr, "Options:\n");
- fprintf(stderr, " -f file Configuration file (default %s)\n", SERVER_CONFIG_FILE);
+ fprintf(stderr, " -f file Configuration file (default %s)\n", _PATH_SERVER_CONFIG_FILE);
fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n");
fprintf(stderr, " -i Started from inetd\n");
+ fprintf(stderr, " -D Do not fork into daemon mode\n");
fprintf(stderr, " -q Quiet (no logging)\n");
fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
- fprintf(stderr, " -g seconds Grace period for authentication (default: 300)\n");
+ fprintf(stderr, " -g seconds Grace period for authentication (default: 600)\n");
fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
- HOST_KEY_FILE);
+ _PATH_HOST_KEY_FILE);
fprintf(stderr, " -u len Maximum hostname length for utmp recording\n");
fprintf(stderr, " -4 Use IPv4 only\n");
fprintf(stderr, " -6 Use IPv6 only\n");
* Force logging to stderr until we have loaded the private host
* key (unless started from inetd)
*/
- log_init(av0,
+ log_init(__progname,
options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
options.log_facility == -1 ? SYSLOG_FACILITY_AUTH : options.log_facility,
- !silent && !inetd_flag);
+ !inetd_flag);
/* Read server configuration options from the configuration file. */
read_server_config(&options, config_file_name);
/* load private host keys */
sensitive_data.host_keys = xmalloc(options.num_host_key_files*sizeof(Key*));
+ for(i = 0; i < options.num_host_key_files; i++)
+ sensitive_data.host_keys[i] = NULL;
sensitive_data.server_key = NULL;
sensitive_data.ssh1_host_key = NULL;
sensitive_data.have_ssh1_key = 0;
log("Disabling protocol version 2. Could not load host key");
options.protocol &= ~SSH_PROTO_2;
}
- if (! options.protocol & (SSH_PROTO_1|SSH_PROTO_2)) {
- if (silent == 0)
- fprintf(stderr, "sshd: no hostkeys available -- exiting.\n");
+ if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
log("sshd: no hostkeys available -- exiting.\n");
exit(1);
}
/* Initialize the log (it is reinitialized below in case we forked). */
if (debug_flag && !inetd_flag)
log_stderr = 1;
- log_init(av0, options.log_level, options.log_facility, log_stderr);
+ log_init(__progname, options.log_level, options.log_facility, log_stderr);
/*
* If not in debugging mode, and not started from inetd, disconnect
#endif /* TIOCNOTTY */
}
/* Reinitialize the log (because of the fork above). */
- log_init(av0, options.log_level, options.log_facility, log_stderr);
+ log_init(__progname, options.log_level, options.log_facility, log_stderr);
/* Initialize the random number generator. */
arc4random_stir();
if (!debug_flag) {
/*
- * Record our pid in /etc/sshd_pid to make it easier
- * to kill the correct sshd. We don\'t want to do
- * this before the bind above because the bind will
+ * Record our pid in /var/run/sshd.pid to make it
+ * easier to kill the correct sshd. We don't want to
+ * do this before the bind above because the bind will
* fail if there already is a daemon, and this will
* overwrite any old pid in the file.
*/
f = fopen(options.pid_file, "wb");
if (f) {
- fprintf(f, "%u\n", (unsigned int) getpid());
+ fprintf(f, "%u\n", (u_int) getpid());
fclose(f);
}
}
- if (options.protocol & SSH_PROTO_1) {
+ if (options.protocol & SSH_PROTO_1)
generate_empheral_server_key();
- /* Schedule server key regeneration alarm. */
- signal(SIGALRM, key_regeneration_alarm);
- alarm(options.key_regeneration_time);
- }
-
/* Arrange to restart on SIGHUP. The handler needs listen_sock. */
signal(SIGHUP, sighup_handler);
sighup_restart();
if (fdset != NULL)
xfree(fdset);
- fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
+ fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
fdset = (fd_set *)xmalloc(fdsetsz);
memset(fdset, 0, fdsetsz);
FD_SET(startup_pipes[i], fdset);
/* Wait in select until there is a connection. */
- if (select(maxfd + 1, fdset, NULL, NULL, NULL) < 0) {
- if (errno != EINTR)
- error("select: %.100s", strerror(errno));
- continue;
+ ret = select(maxfd+1, fdset, NULL, NULL, NULL);
+ if (ret < 0 && errno != EINTR)
+ error("select: %.100s", strerror(errno));
+ if (key_used && key_do_regen) {
+ generate_empheral_server_key();
+ key_used = 0;
+ key_do_regen = 0;
}
+ if (ret < 0)
+ continue;
+
for (i = 0; i < options.max_startups; i++)
if (startup_pipes[i] != -1 &&
FD_ISSET(startup_pipes[i], fdset)) {
/*
* the read end of the pipe is ready
* if the child has closed the pipe
- * after successfull authentication
+ * after successful authentication
* or if the child has died
*/
close(startup_pipes[i]);
startups++;
break;
}
-
+
/*
* Got connection. Fork a child to handle it, unless
* we are in debugging mode.
close_listen_socks();
sock_in = newsock;
sock_out = newsock;
- log_init(av0, options.log_level, options.log_facility, log_stderr);
+ log_init(__progname, options.log_level, options.log_facility, log_stderr);
break;
}
}
close(startup_p[1]);
/* Mark that the key has been used (it was "given" to the child). */
- key_used = 1;
+ if ((options.protocol & SSH_PROTO_1) &&
+ key_used == 0) {
+ /* Schedule server key regeneration alarm. */
+ signal(SIGALRM, key_regeneration_alarm);
+ alarm(options.key_regeneration_time);
+ key_used = 1;
+ }
arc4random_stir();
linger.l_linger = 5;
setsockopt(sock_in, SOL_SOCKET, SO_LINGER, (void *) &linger, sizeof(linger));
+ /* Set keepalives if requested. */
+ if (options.keepalives &&
+ setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
+ sizeof(on)) < 0)
+ error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
+
/*
* Register our connection. This turns encryption off because we do
* not have a key.
{
struct request_info req;
- request_init(&req, RQ_DAEMON, av0, RQ_FILE, sock_in, NULL);
+ request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, NULL);
fromhost(&req);
if (!hosts_access(&req)) {
sshd_exchange_identification(sock_in, sock_out);
/*
- * Check that the connection comes from a privileged port. Rhosts-
- * and Rhosts-RSA-Authentication only make sense from priviledged
+ * Check that the connection comes from a privileged port.
+ * Rhosts-Authentication only makes sense from priviledged
* programs. Of course, if the intruder has root access on his local
* machine, he can connect from any port. So do not use these
* authentication methods from machines that you do not trust.
*/
if (remote_port >= IPPORT_RESERVED ||
remote_port < IPPORT_RESERVED / 2) {
- debug("Rhosts Authentication methods disabled, "
+ debug("Rhosts Authentication disabled, "
"originating port not trusted.");
options.rhosts_authentication = 0;
- options.rhosts_rsa_authentication = 0;
}
#ifdef KRB4
if (!packet_connection_is_ipv4() &&
* SSH1 key exchange
*/
void
-do_ssh1_kex()
+do_ssh1_kex(void)
{
int i, len;
int plen, slen;
+ int rsafail = 0;
BIGNUM *session_key_int;
- unsigned char session_key[SSH_SESSION_KEY_LENGTH];
- unsigned char cookie[8];
- unsigned int cipher_type, auth_mask, protocol_flags;
+ u_char session_key[SSH_SESSION_KEY_LENGTH];
+ u_char cookie[8];
+ u_int cipher_type, auth_mask, protocol_flags;
u_int32_t rand = 0;
/*
if (options.afs_token_passing)
auth_mask |= 1 << SSH_PASS_AFS_TOKEN;
#endif
-#ifdef SKEY
- if (options.skey_authentication == 1)
+ if (options.challenge_reponse_authentication == 1)
auth_mask |= 1 << SSH_AUTH_TIS;
-#endif
if (options.password_authentication)
auth_mask |= 1 << SSH_AUTH_PASSWORD;
packet_put_int(auth_mask);
* with larger modulus first).
*/
if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) {
- /* Private key has bigger modulus. */
+ /* Server key has bigger modulus. */
if (BN_num_bits(sensitive_data.server_key->rsa->n) <
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
SSH_KEY_BITS_RESERVED);
}
- rsa_private_decrypt(session_key_int, session_key_int,
- sensitive_data.server_key->rsa);
- rsa_private_decrypt(session_key_int, session_key_int,
- sensitive_data.ssh1_host_key->rsa);
+ if (rsa_private_decrypt(session_key_int, session_key_int,
+ sensitive_data.server_key->rsa) <= 0)
+ rsafail++;
+ if (rsa_private_decrypt(session_key_int, session_key_int,
+ sensitive_data.ssh1_host_key->rsa) <= 0)
+ rsafail++;
} else {
/* Host key has bigger modulus (or they are equal). */
if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
BN_num_bits(sensitive_data.server_key->rsa->n),
SSH_KEY_BITS_RESERVED);
}
- rsa_private_decrypt(session_key_int, session_key_int,
- sensitive_data.ssh1_host_key->rsa);
- rsa_private_decrypt(session_key_int, session_key_int,
- sensitive_data.server_key->rsa);
+ if (rsa_private_decrypt(session_key_int, session_key_int,
+ sensitive_data.ssh1_host_key->rsa) < 0)
+ rsafail++;
+ if (rsa_private_decrypt(session_key_int, session_key_int,
+ sensitive_data.server_key->rsa) < 0)
+ rsafail++;
}
compute_session_id(session_id, cookie,
* least significant 256 bits of the integer; the first byte of the
* key is in the highest bits.
*/
- BN_mask_bits(session_key_int, sizeof(session_key) * 8);
- len = BN_num_bytes(session_key_int);
- if (len < 0 || len > sizeof(session_key))
- fatal("do_connection: bad len from %s: session_key_int %d > sizeof(session_key) %d",
- get_remote_ipaddr(),
- len, sizeof(session_key));
- memset(session_key, 0, sizeof(session_key));
- BN_bn2bin(session_key_int, session_key + sizeof(session_key) - len);
-
+ if (!rsafail) {
+ BN_mask_bits(session_key_int, sizeof(session_key) * 8);
+ len = BN_num_bytes(session_key_int);
+ if (len < 0 || len > sizeof(session_key)) {
+ error("do_connection: bad session key len from %s: "
+ "session_key_int %d > sizeof(session_key) %d",
+ get_remote_ipaddr(), len, (int)sizeof(session_key));
+ rsafail++;
+ } else {
+ memset(session_key, 0, sizeof(session_key));
+ BN_bn2bin(session_key_int,
+ session_key + sizeof(session_key) - len);
+ }
+ }
+ if (rsafail) {
+ log("do_connection: generating a fake encryption key");
+ for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
+ if (i % 4 == 0)
+ rand = arc4random();
+ session_key[i] = rand & 0xff;
+ rand >>= 8;
+ }
+ }
/* Destroy the decrypted integer. It is no longer needed. */
BN_clear_free(session_key_int);
* SSH2 key exchange: diffie-hellman-group1-sha1
*/
void
-do_ssh2_kex()
+do_ssh2_kex(void)
{
Buffer *server_kexinit;
Buffer *client_kexinit;
#endif
int payload_len, dlen;
int slen;
- unsigned char *signature = NULL;
- unsigned char *server_host_key_blob = NULL;
- unsigned int sbloblen;
- unsigned int klen, kout;
- unsigned char *kbuf;
- unsigned char *hash;
+ u_char *signature = NULL;
+ u_char *server_host_key_blob = NULL;
+ u_int sbloblen;
+ u_int klen, kout;
+ u_char *kbuf;
+ u_char *hash;
BIGNUM *shared_secret = 0;
DH *dh;
BIGNUM *dh_client_pub = 0;
fatal("Unsupported hostkey type %d", kex->hostkey_type);
/* KEXDH */
+ /* generate DH key */
+ dh = dh_new_group1(); /* XXX depends on 'kex' */
+ dh_gen_key(dh);
+
debug("Wait SSH2_MSG_KEXDH_INIT.");
packet_read_expect(&payload_len, SSH2_MSG_KEXDH_INIT);
debug("bits %d", BN_num_bits(dh_client_pub));
#endif
- /* generate DH key */
- dh = dh_new_group1(); /* XXX depends on 'kex' */
-
#ifdef DEBUG_KEXDH
fprintf(stderr, "\np= ");
BN_print_fp(stderr, dh->p);
fprintf(stderr, "\npub= ");
BN_print_fp(stderr, dh->pub_key);
fprintf(stderr, "\n");
- DHparams_print_fp(stderr, dh);
+ DHparams_print_fp(stderr, dh);
#endif
if (!dh_pub_is_valid(dh, dh_client_pub))
packet_disconnect("bad client public DH value");
buffer_free(server_kexinit);
xfree(client_kexinit);
xfree(server_kexinit);
+ BN_free(dh_client_pub);
#ifdef DEBUG_KEXDH
fprintf(stderr, "hash == ");
for (i = 0; i< 20; i++)
packet_write_wait();
kex_derive_keys(kex, hash, shared_secret);
+ BN_clear_free(shared_secret);
packet_set_kex(kex);
/* have keys, free DH */
#endif
int payload_len, dlen;
int slen, nbits;
- unsigned char *signature = NULL;
- unsigned char *server_host_key_blob = NULL;
- unsigned int sbloblen;
- unsigned int klen, kout;
- unsigned char *kbuf;
- unsigned char *hash;
+ u_char *signature = NULL;
+ u_char *server_host_key_blob = NULL;
+ u_int sbloblen;
+ u_int klen, kout;
+ u_char *kbuf;
+ u_char *hash;
BIGNUM *shared_secret = 0;
DH *dh;
BIGNUM *dh_client_pub = 0;
packet_send();
packet_write_wait();
+ /* Compute our exchange value in parallel with the client */
+
+ dh_gen_key(dh);
+
debug("Wait SSH2_MSG_KEX_DH_GEX_INIT.");
packet_read_expect(&payload_len, SSH2_MSG_KEX_DH_GEX_INIT);
fprintf(stderr, "\npub= ");
BN_print_fp(stderr, dh->pub_key);
fprintf(stderr, "\n");
- DHparams_print_fp(stderr, dh);
+ DHparams_print_fp(stderr, dh);
#endif
if (!dh_pub_is_valid(dh, dh_client_pub))
packet_disconnect("bad client public DH value");
buffer_free(server_kexinit);
xfree(client_kexinit);
xfree(server_kexinit);
+ BN_free(dh_client_pub);
#ifdef DEBUG_KEXDH
fprintf(stderr, "hash == ");
for (i = 0; i< 20; i++)
packet_write_wait();
kex_derive_keys(kex, hash, shared_secret);
+ BN_clear_free(shared_secret);
packet_set_kex(kex);
/* have keys, free DH */
andersk / openssh.git / blobdiff