*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.166 2001/02/11 12:59:25 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.191 2001/04/05 10:42:57 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"
#include "canohost.h"
#include "auth.h"
#include "misc.h"
+#include "dispatch.h"
#ifdef LIBWRAP
#include <tcpd.h>
char *client_version_string = NULL;
char *server_version_string = NULL;
+/* for rekeying XXX fixme */
+Kex *xxx_kex;
+
/*
* Any really sensitive data in the application is contained in this
* structure. The idea is that this structure could be locked into memory so
* 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;
/*
* problems.
*/
void
-generate_empheral_server_key(void)
+generate_ephemeral_server_key(void)
{
- log("Generating %s%d bit RSA key.", sensitive_data.server_key ? "new " : "",
- options.server_key_bits);
+ u_int32_t rand = 0;
+ int i;
+
+ verbose("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);
+ sensitive_data.server_key = key_generate(KEY_RSA1,
+ options.server_key_bits);
+ verbose("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();
- log("RSA key generation complete.");
}
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) {
}
}
sensitive_data.ssh1_host_key = NULL;
-}
-Key *
-load_private_key_autodetect(const char *filename)
-{
- struct stat st;
- int type;
- Key *public, *private;
-
- if (stat(filename, &st) < 0) {
- perror(filename);
- return NULL;
- }
- /*
- * try to load the public key. right now this only works for RSA1,
- * since SSH2 keys are fully encrypted
- */
- type = KEY_RSA1;
- public = key_new(type);
- if (!load_public_key(filename, public, NULL)) {
- /* ok, so we will assume this is 'some' key */
- type = KEY_UNSPEC;
- }
- key_free(public);
-
- /* Ok, try key with empty passphrase */
- private = key_new(type);
- if (load_private_key(filename, "", private, NULL)) {
- debug("load_private_key_autodetect: type %d %s",
- private->type, key_type(private));
- return private;
- }
- key_free(private);
- return NULL;
+ memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH);
}
char *
int listen_sock, maxfd;
int startup_p[2];
int startups = 0;
+ Key *key;
int ret, key_used = 0;
__progname = get_progname(av[0]);
exit(1);
}
}
+ SSLeay_add_all_algorithms();
/*
* Force logging to stderr until we have loaded the private host
options.log_facility == -1 ? SYSLOG_FACILITY_AUTH : options.log_facility,
!inetd_flag);
+ seed_rng();
+
/* Read server configuration options from the configuration file. */
read_server_config(&options, config_file_name);
sensitive_data.have_ssh2_key = 0;
for(i = 0; i < options.num_host_key_files; i++) {
- Key *key = load_private_key_autodetect(options.host_key_files[i]);
+ key = key_load_private(options.host_key_files[i], "", NULL);
+ sensitive_data.host_keys[i] = key;
if (key == NULL) {
error("Could not load host key: %.200s: %.100s",
options.host_key_files[i], strerror(errno));
+ sensitive_data.host_keys[i] = NULL;
continue;
}
switch(key->type){
sensitive_data.have_ssh2_key = 1;
break;
}
- sensitive_data.host_keys[i] = key;
+ debug("private host key: #%d type %d %s", i, key->type,
+ key_type(key));
}
if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
log("Disabling protocol version 1. Could not load host key");
options.protocol &= ~SSH_PROTO_2;
}
if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
- log("sshd: no hostkeys available -- exiting.\n");
+ log("sshd: no hostkeys available -- exiting.");
exit(1);
}
/* 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;
}
fromhost(&req);
if (!hosts_access(&req)) {
+ refuse(&req);
close(sock_in);
close(sock_out);
- refuse(&req);
}
/*XXX IPv6 verbose("Connection from %.500s port %d", eval_client(&req), remote_port); */
}
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
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");
- for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
- if (i % 4 == 0)
- rand = arc4random();
- session_key[i] = rand & 0xff;
- rand >>= 8;
- }
+ 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);
void
do_ssh2_kex(void)
{
- Buffer *server_kexinit;
- Buffer *client_kexinit;
- int payload_len;
- int i;
Kex *kex;
- char *cprop[PROPOSAL_MAX];
-
-/* KEXINIT */
if (options.ciphers != NULL) {
myproposal[PROPOSAL_ENC_ALGS_CTOS] =
myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
}
+ myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+ compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
+ myproposal[PROPOSAL_ENC_ALGS_STOC] =
+ compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
+
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();
- server_kexinit = kex_init(myproposal);
- client_kexinit = xmalloc(sizeof(*client_kexinit));
- buffer_init(client_kexinit);
+ /* start key exchange */
+ kex = kex_setup(myproposal);
+ kex->server = 1;
+ kex->client_version_string=client_version_string;
+ kex->server_version_string=server_version_string;
+ kex->load_host_key=&get_hostkey_by_type;
- /* algorithm negotiation */
- kex_exchange_kexinit(server_kexinit, client_kexinit, cprop);
- kex = kex_choose_conf(cprop, myproposal, 1);
- for (i = 0; i < PROPOSAL_MAX; i++)
- xfree(cprop[i]);
+ xxx_kex = kex;
- switch (kex->kex_type) {
- case DH_GRP1_SHA1:
- ssh_dh1_server(kex, client_kexinit, server_kexinit);
- break;
- case DH_GEX_SHA1:
- ssh_dhgex_server(kex, client_kexinit, server_kexinit);
- break;
- default:
- fatal("Unsupported key exchange %d", kex->kex_type);
- }
+ dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
- debug("send SSH2_MSG_NEWKEYS.");
- packet_start(SSH2_MSG_NEWKEYS);
- packet_send();
- packet_write_wait();
- debug("done: send SSH2_MSG_NEWKEYS.");
-
- debug("Wait SSH2_MSG_NEWKEYS.");
- packet_read_expect(&payload_len, SSH2_MSG_NEWKEYS);
- debug("GOT SSH2_MSG_NEWKEYS.");
+ session_id2 = kex->session_id;
+ session_id2_len = kex->session_id_len;
#ifdef DEBUG_KEXDH
/* send 1st encrypted/maced/compressed message */
packet_send();
packet_write_wait();
#endif
-
- debug("done: KEX2.");
-}
-
-/*
- * SSH2 key exchange
- */
-
-/* diffie-hellman-group1-sha1 */
-
-void
-ssh_dh1_server(Kex *kex, Buffer *client_kexinit, Buffer *server_kexinit)
-{
-#ifdef DEBUG_KEXDH
- int i;
-#endif
- int payload_len, dlen;
- int slen;
- 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;
- Key *hostkey;
-
- hostkey = get_hostkey_by_type(kex->hostkey_type);
- if (hostkey == NULL)
- 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);
-
- /* key, cert */
- dh_client_pub = BN_new();
- if (dh_client_pub == NULL)
- fatal("dh_client_pub == NULL");
- packet_get_bignum2(dh_client_pub, &dlen);
-
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\ndh_client_pub= ");
- BN_print_fp(stderr, dh_client_pub);
- fprintf(stderr, "\n");
- debug("bits %d", BN_num_bits(dh_client_pub));
-#endif
-
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\np= ");
- BN_print_fp(stderr, dh->p);
- fprintf(stderr, "\ng= ");
- bn_print(dh->g);
- fprintf(stderr, "\npub= ");
- BN_print_fp(stderr, dh->pub_key);
- fprintf(stderr, "\n");
- DHparams_print_fp(stderr, dh);
-#endif
- if (!dh_pub_is_valid(dh, dh_client_pub))
- packet_disconnect("bad client public DH value");
-
- klen = DH_size(dh);
- kbuf = xmalloc(klen);
- kout = DH_compute_key(kbuf, dh_client_pub, dh);
-
-#ifdef DEBUG_KEXDH
- debug("shared secret: len %d/%d", klen, kout);
- fprintf(stderr, "shared secret == ");
- for (i = 0; i< kout; i++)
- fprintf(stderr, "%02x", (kbuf[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- shared_secret = BN_new();
-
- BN_bin2bn(kbuf, kout, shared_secret);
- memset(kbuf, 0, klen);
- xfree(kbuf);
-
- /* XXX precompute? */
- key_to_blob(hostkey, &server_host_key_blob, &sbloblen);
-
- /* calc H */ /* XXX depends on 'kex' */
- hash = kex_hash(
- client_version_string,
- server_version_string,
- buffer_ptr(client_kexinit), buffer_len(client_kexinit),
- buffer_ptr(server_kexinit), buffer_len(server_kexinit),
- (char *)server_host_key_blob, sbloblen,
- dh_client_pub,
- dh->pub_key,
- shared_secret
- );
- buffer_free(client_kexinit);
- 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++)
- fprintf(stderr, "%02x", (hash[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- /* save session id := H */
- /* XXX hashlen depends on KEX */
- session_id2_len = 20;
- session_id2 = xmalloc(session_id2_len);
- memcpy(session_id2, hash, session_id2_len);
-
- /* sign H */
- /* XXX hashlen depends on KEX */
- key_sign(hostkey, &signature, &slen, hash, 20);
-
- destroy_sensitive_data();
-
- /* send server hostkey, DH pubkey 'f' and singed H */
- packet_start(SSH2_MSG_KEXDH_REPLY);
- packet_put_string((char *)server_host_key_blob, sbloblen);
- packet_put_bignum2(dh->pub_key); /* f */
- packet_put_string((char *)signature, slen);
- packet_send();
- xfree(signature);
- xfree(server_host_key_blob);
- packet_write_wait();
-
- kex_derive_keys(kex, hash, shared_secret);
- BN_clear_free(shared_secret);
- packet_set_kex(kex);
-
- /* have keys, free DH */
- DH_free(dh);
-}
-
-/* diffie-hellman-group-exchange-sha1 */
-
-void
-ssh_dhgex_server(Kex *kex, Buffer *client_kexinit, Buffer *server_kexinit)
-{
-#ifdef DEBUG_KEXDH
- int i;
-#endif
- int payload_len, dlen;
- int slen, nbits;
- 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;
- Key *hostkey;
-
- hostkey = get_hostkey_by_type(kex->hostkey_type);
- if (hostkey == NULL)
- fatal("Unsupported hostkey type %d", kex->hostkey_type);
-
-/* KEXDHGEX */
- debug("Wait SSH2_MSG_KEX_DH_GEX_REQUEST.");
- packet_read_expect(&payload_len, SSH2_MSG_KEX_DH_GEX_REQUEST);
- nbits = packet_get_int();
- dh = choose_dh(nbits);
-
- debug("Sending SSH2_MSG_KEX_DH_GEX_GROUP.");
- packet_start(SSH2_MSG_KEX_DH_GEX_GROUP);
- packet_put_bignum2(dh->p);
- packet_put_bignum2(dh->g);
- 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);
-
- /* key, cert */
- dh_client_pub = BN_new();
- if (dh_client_pub == NULL)
- fatal("dh_client_pub == NULL");
- packet_get_bignum2(dh_client_pub, &dlen);
-
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\ndh_client_pub= ");
- BN_print_fp(stderr, dh_client_pub);
- fprintf(stderr, "\n");
- debug("bits %d", BN_num_bits(dh_client_pub));
-#endif
-
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\np= ");
- BN_print_fp(stderr, dh->p);
- fprintf(stderr, "\ng= ");
- bn_print(dh->g);
- fprintf(stderr, "\npub= ");
- BN_print_fp(stderr, dh->pub_key);
- fprintf(stderr, "\n");
- DHparams_print_fp(stderr, dh);
-#endif
- if (!dh_pub_is_valid(dh, dh_client_pub))
- packet_disconnect("bad client public DH value");
-
- klen = DH_size(dh);
- kbuf = xmalloc(klen);
- kout = DH_compute_key(kbuf, dh_client_pub, dh);
-
-#ifdef DEBUG_KEXDH
- debug("shared secret: len %d/%d", klen, kout);
- fprintf(stderr, "shared secret == ");
- for (i = 0; i< kout; i++)
- fprintf(stderr, "%02x", (kbuf[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- shared_secret = BN_new();
-
- BN_bin2bn(kbuf, kout, shared_secret);
- memset(kbuf, 0, klen);
- xfree(kbuf);
-
- /* XXX precompute? */
- key_to_blob(hostkey, &server_host_key_blob, &sbloblen);
-
- /* calc H */ /* XXX depends on 'kex' */
- hash = kex_hash_gex(
- client_version_string,
- server_version_string,
- buffer_ptr(client_kexinit), buffer_len(client_kexinit),
- buffer_ptr(server_kexinit), buffer_len(server_kexinit),
- (char *)server_host_key_blob, sbloblen,
- nbits, dh->p, dh->g,
- dh_client_pub,
- dh->pub_key,
- shared_secret
- );
- buffer_free(client_kexinit);
- 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++)
- fprintf(stderr, "%02x", (hash[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- /* save session id := H */
- /* XXX hashlen depends on KEX */
- session_id2_len = 20;
- session_id2 = xmalloc(session_id2_len);
- memcpy(session_id2, hash, session_id2_len);
-
- /* sign H */
- /* XXX hashlen depends on KEX */
- key_sign(hostkey, &signature, &slen, hash, 20);
-
- destroy_sensitive_data();
-
- /* send server hostkey, DH pubkey 'f' and singed H */
- packet_start(SSH2_MSG_KEX_DH_GEX_REPLY);
- packet_put_string((char *)server_host_key_blob, sbloblen);
- packet_put_bignum2(dh->pub_key); /* f */
- packet_put_string((char *)signature, slen);
- packet_send();
- xfree(signature);
- xfree(server_host_key_blob);
- packet_write_wait();
-
- kex_derive_keys(kex, hash, shared_secret);
- BN_clear_free(shared_secret);
- packet_set_kex(kex);
-
- /* have keys, free DH */
- DH_free(dh);
+ debug("KEX done");
}
andersk / openssh.git / blobdiff