*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.155 2001/01/21 19:06:00 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.178 2001/03/23 14:28:32 markus Exp $");
#include <openssl/dh.h>
#include <openssl/bn.h>
#include "ssh2.h"
#include "xmalloc.h"
#include "rsa.h"
-#include "pty.h"
+#include "sshpty.h"
#include "packet.h"
#include "mpaux.h"
#include "log.h"
* not very useful. Currently, memory locking is not implemented.
*/
struct {
- Key *server_key; /* empheral server key */
+ Key *server_key; /* ephemeral server key */
Key *ssh1_host_key; /* ssh1 host key */
Key **host_keys; /* all private host keys */
int have_ssh1_key;
int have_ssh2_key;
+ u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH];
} sensitive_data;
/*
* Restarts the server.
*/
void
-sighup_restart()
+sighup_restart(void)
{
log("Received SIGHUP; restarting.");
close_listen_socks();
* problems.
*/
void
-generate_empheral_server_key(void)
+generate_ephemeral_server_key(void)
{
+ u_int32_t rand = 0;
+ int i;
+
log("Generating %s%d bit RSA key.", sensitive_data.server_key ? "new " : "",
options.server_key_bits);
if (sensitive_data.server_key != NULL)
key_free(sensitive_data.server_key);
sensitive_data.server_key = key_generate(KEY_RSA1, options.server_key_bits);
- arc4random_stir();
log("RSA key generation complete.");
+
+ for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
+ if (i % 4 == 0)
+ rand = arc4random();
+ sensitive_data.ssh1_cookie[i] = rand & 0xff;
+ rand >>= 8;
+ }
+ arc4random_stir();
}
void
fatal_cleanup();
}
- /* Read other side\'s version identification. */
+ /* Read other side's version identification. */
+ memset(buf, 0, sizeof(buf));
for (i = 0; i < sizeof(buf) - 1; i++) {
if (atomicio(read, sock_in, &buf[i], 1) != 1) {
- log("Did not receive ident string from %s.", get_remote_ipaddr());
+ log("Did not receive identification string from %s.",
+ get_remote_ipaddr());
fatal_cleanup();
}
if (buf[i] == '\r') {
- buf[i] = '\n';
- buf[i + 1] = 0;
+ buf[i] = 0;
/* Kludge for F-Secure Macintosh < 1.0.2 */
if (i == 12 &&
strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
continue;
}
if (buf[i] == '\n') {
- /* buf[i] == '\n' */
- buf[i + 1] = 0;
+ buf[i] = 0;
break;
}
}
compat_datafellows(remote_version);
+ if (datafellows & SSH_BUG_SCANNER) {
+ log("scanned from %s with %s. Don't panic.",
+ get_remote_ipaddr(), client_version_string);
+ fatal_cleanup();
+ }
+
mismatch = 0;
switch(remote_major) {
case 1:
break;
}
chop(server_version_string);
- chop(client_version_string);
debug("Local version string %.200s", server_version_string);
if (mismatch) {
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;
}
}
sensitive_data.ssh1_host_key = NULL;
+ memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH);
}
Key *
load_private_key_autodetect(const char *filename)
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;
inetd_flag = 1;
break;
case 'Q':
- silent = 1;
+ /* ignored */
break;
case 'q':
options.log_level = SYSLOG_LEVEL_QUIET;
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);
+
+ seed_rng();
/* Read server configuration options from the configuration file. */
read_server_config(&options, config_file_name);
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");
- log("sshd: no hostkeys available -- exiting.\n");
+ if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
+ log("sshd: no hostkeys available -- exiting.");
exit(1);
}
/* Disconnect from the controlling tty. */
#ifdef TIOCNOTTY
- fd = open("/dev/tty", O_RDWR | O_NOCTTY);
+ fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
if (fd >= 0) {
(void) ioctl(fd, TIOCNOTTY, NULL);
close(fd);
/* Chdir to the root directory so that the current disk can be
unmounted if desired. */
chdir("/");
+
+ /* ignore SIGPIPE */
+ signal(SIGPIPE, SIG_IGN);
/* Start listening for a socket, unless started from inetd. */
if (inetd_flag) {
*/
debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
if (options.protocol & SSH_PROTO_1)
- generate_empheral_server_key();
+ generate_ephemeral_server_key();
} else {
for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
debug("Bind to port %s on %s.", strport, ntop);
/* Bind the socket to the desired port. */
- if ((bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) &&
- (!ai->ai_next)) {
- error("Bind to port %s on %s failed: %.200s.",
- strport, ntop, strerror(errno));
+ if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
+ if (!ai->ai_next)
+ error("Bind to port %s on %s failed: %.200s.",
+ strport, ntop, strerror(errno));
close(listen_sock);
continue;
}
}
}
if (options.protocol & SSH_PROTO_1)
- generate_empheral_server_key();
+ generate_ephemeral_server_key();
/* Arrange to restart on SIGHUP. The handler needs listen_sock. */
signal(SIGHUP, sighup_handler);
if (ret < 0 && errno != EINTR)
error("select: %.100s", strerror(errno));
if (key_used && key_do_regen) {
- generate_empheral_server_key();
+ generate_ephemeral_server_key();
key_used = 0;
key_do_regen = 0;
}
startups++;
break;
}
-
+
/*
* Got connection. Fork a child to handle it, unless
* we are in debugging mode.
options.kerberos_authentication = 0;
}
#endif /* KRB4 */
+#ifdef AFS
+ /* If machine has AFS, set process authentication group. */
+ if (k_hasafs()) {
+ k_setpag();
+ k_unlog();
+ }
+#endif /* AFS */
packet_set_nonblocking();
{
int i, len;
int plen, slen;
+ int rsafail = 0;
BIGNUM *session_key_int;
u_char session_key[SSH_SESSION_KEY_LENGTH];
u_char cookie[8];
if (options.afs_token_passing)
auth_mask |= 1 << SSH_PASS_AFS_TOKEN;
#endif
- if (options.skey_authentication == 1)
+ if (options.challenge_reponse_authentication == 1)
auth_mask |= 1 << SSH_AUTH_TIS;
if (options.password_authentication)
auth_mask |= 1 << SSH_AUTH_PASSWORD;
* 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,
- sensitive_data.ssh1_host_key->rsa->n,
- sensitive_data.server_key->rsa->n);
-
- /* Destroy the private and public keys. They will no longer be needed. */
- destroy_sensitive_data();
-
/*
* Extract session key from the decrypted integer. The key is in the
* 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) %lu",
+ get_remote_ipaddr(), len, (u_long)sizeof(session_key));
+ rsafail++;
+ } else {
+ memset(session_key, 0, sizeof(session_key));
+ BN_bn2bin(session_key_int,
+ session_key + sizeof(session_key) - len);
+
+ compute_session_id(session_id, cookie,
+ sensitive_data.ssh1_host_key->rsa->n,
+ sensitive_data.server_key->rsa->n);
+ /*
+ * Xor the first 16 bytes of the session key with the
+ * session id.
+ */
+ for (i = 0; i < 16; i++)
+ session_key[i] ^= session_id[i];
+ }
+ }
+ if (rsafail) {
+ int bytes = BN_num_bytes(session_key_int);
+ char *buf = xmalloc(bytes);
+ MD5_CTX md;
+
+ log("do_connection: generating a fake encryption key");
+ BN_bn2bin(session_key_int, buf);
+ MD5_Init(&md);
+ MD5_Update(&md, buf, bytes);
+ MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
+ MD5_Final(session_key, &md);
+ MD5_Init(&md);
+ MD5_Update(&md, session_key, 16);
+ MD5_Update(&md, buf, bytes);
+ MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
+ MD5_Final(session_key + 16, &md);
+ memset(buf, 0, bytes);
+ xfree(buf);
+ for (i = 0; i < 16; i++)
+ session_id[i] = session_key[i] ^ session_key[i + 16];
+ }
+ /* Destroy the private and public keys. They will no longer be needed. */
+ destroy_sensitive_data();
/* Destroy the decrypted integer. It is no longer needed. */
BN_clear_free(session_key_int);
- /* Xor the first 16 bytes of the session key with the session id. */
- for (i = 0; i < 16; i++)
- session_key[i] ^= session_id[i];
-
/* Set the session key. From this on all communications will be encrypted. */
packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
myproposal[PROPOSAL_ENC_ALGS_CTOS] =
myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
}
+ if (options.macs != NULL) {
+ myproposal[PROPOSAL_MAC_ALGS_CTOS] =
+ myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
+ }
myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
+ myproposal[PROPOSAL_ENC_ALGS_STOC] =
+ compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
+
server_kexinit = kex_init(myproposal);
client_kexinit = xmalloc(sizeof(*client_kexinit));
buffer_init(client_kexinit);
/* KEXDH */
/* generate DH key */
dh = dh_new_group1(); /* XXX depends on 'kex' */
- dh_gen_key(dh);
+ dh_gen_key(dh, kex->we_need * 8);
debug("Wait SSH2_MSG_KEXDH_INIT.");
packet_read_expect(&payload_len, SSH2_MSG_KEXDH_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 */
/* Compute our exchange value in parallel with the client */
- dh_gen_key(dh);
+ dh_gen_key(dh, kex->we_need * 8);
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