- Merge big update to OpenSSH-2.0 from OpenBSD CVS
[README.openssh2]
- interop w/ F-secure windows client
- sync documentation
- ssh_host_dsa_key not ssh_dsa_key
[auth-rsa.c]
- missing fclose
[auth.c authfile.c compat.c dsa.c dsa.h hostfile.c key.c key.h radix.c]
[readconf.c readconf.h ssh-add.c ssh-keygen.c ssh.c ssh.h sshconnect.c]
[sshd.c uuencode.c uuencode.h authfile.h]
- add DSA pubkey auth and other SSH2 fixes. use ssh-keygen -[xX]
for trading keys with the real and the original SSH, directly from the
people who invented the SSH protocol.
[auth.c auth.h authfile.c sshconnect.c auth1.c auth2.c sshconnect.h]
[sshconnect1.c sshconnect2.c]
- split auth/sshconnect in one file per protocol version
[sshconnect2.c]
- remove debug
[uuencode.c]
- add trailing =
[version.h]
- OpenSSH-2.0
[ssh-keygen.1 ssh-keygen.c]
- add -R flag: exit code indicates if RSA is alive
[sshd.c]
- remove unused
silent if -Q is specified
[ssh.h]
- host key becomes /etc/ssh_host_dsa_key
[readconf.c servconf.c ]
- ssh/sshd default to proto 1 and 2
[uuencode.c]
- remove debug
[auth2.c ssh-keygen.c sshconnect2.c sshd.c]
- xfree DSA blobs
[auth2.c serverloop.c session.c]
- cleanup logging for sshd/2, respect PasswordAuth no
[sshconnect2.c]
- less debug, respect .ssh/config
[README.openssh2 channels.c channels.h]
- clientloop.c session.c ssh.c
- support for x11-fwding, client+server
diff --git a/sshconnect2.c b/sshconnect2.c
new file mode 100644
index 0000000..31ef308
--- /dev/null
+++ b/sshconnect2.c
@@ -0,0 +1,449 @@
+/*
+ * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by Markus Friedl.
+ * 4. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$OpenBSD: sshconnect2.c,v 1.4 2000/04/27 17:54:01 markus Exp $");
+
+#include <openssl/bn.h>
+#include <openssl/rsa.h>
+#include <openssl/dsa.h>
+#include <openssl/md5.h>
+#include <openssl/dh.h>
+#include <openssl/hmac.h>
+
+#include "ssh.h"
+#include "xmalloc.h"
+#include "rsa.h"
+#include "buffer.h"
+#include "packet.h"
+#include "cipher.h"
+#include "uidswap.h"
+#include "compat.h"
+#include "readconf.h"
+#include "bufaux.h"
+#include "ssh2.h"
+#include "kex.h"
+#include "myproposal.h"
+#include "key.h"
+#include "dsa.h"
+#include "sshconnect.h"
+#include "authfile.h"
+
+/* import */
+extern char *client_version_string;
+extern char *server_version_string;
+extern Options options;
+
+/*
+ * SSH2 key exchange
+ */
+
+unsigned char *session_id2 = NULL;
+int session_id2_len = 0;
+
+void
+ssh_kex2(char *host, struct sockaddr *hostaddr)
+{
+ Kex *kex;
+ char *cprop[PROPOSAL_MAX];
+ char *sprop[PROPOSAL_MAX];
+ Buffer *client_kexinit;
+ Buffer *server_kexinit;
+ int payload_len, dlen;
+ unsigned int klen, kout;
+ char *ptr;
+ char *signature = NULL;
+ unsigned int slen;
+ char *server_host_key_blob = NULL;
+ Key *server_host_key;
+ unsigned int sbloblen;
+ DH *dh;
+ BIGNUM *dh_server_pub = 0;
+ BIGNUM *shared_secret = 0;
+ int i;
+ unsigned char *kbuf;
+ unsigned char *hash;
+
+/* KEXINIT */
+
+ debug("Sending KEX init.");
+ if (options.ciphers != NULL) {
+ myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+ myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
+ } else if (
+ options.cipher == SSH_CIPHER_ARCFOUR ||
+ options.cipher == SSH_CIPHER_3DES_CBC ||
+ options.cipher == SSH_CIPHER_CAST128_CBC ||
+ options.cipher == SSH_CIPHER_BLOWFISH_CBC) {
+ myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+ myproposal[PROPOSAL_ENC_ALGS_STOC] = cipher_name(options.cipher);
+ }
+ if (options.compression) {
+ myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib";
+ myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib";
+ } else {
+ myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none";
+ myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
+ }
+ for (i = 0; i < PROPOSAL_MAX; i++)
+ cprop[i] = xstrdup(myproposal[i]);
+
+ client_kexinit = kex_init(cprop);
+ packet_start(SSH2_MSG_KEXINIT);
+ packet_put_raw(buffer_ptr(client_kexinit), buffer_len(client_kexinit));
+ packet_send();
+ packet_write_wait();
+
+ debug("done");
+
+ packet_read_expect(&payload_len, SSH2_MSG_KEXINIT);
+
+ /* save payload for session_id */
+ server_kexinit = xmalloc(sizeof(*server_kexinit));
+ buffer_init(server_kexinit);
+ ptr = packet_get_raw(&payload_len);
+ buffer_append(server_kexinit, ptr, payload_len);
+
+ /* skip cookie */
+ for (i = 0; i < 16; i++)
+ (void) packet_get_char();
+ /* kex init proposal strings */
+ for (i = 0; i < PROPOSAL_MAX; i++) {
+ sprop[i] = packet_get_string(NULL);
+ debug("got kexinit string: %s", sprop[i]);
+ }
+ i = (int) packet_get_char();
+ debug("first kex follow == %d", i);
+ i = packet_get_int();
+ debug("reserved == %d", i);
+ packet_done();
+
+ debug("done read kexinit");
+ kex = kex_choose_conf(cprop, sprop, 0);
+
+/* KEXDH */
+
+ debug("Sending SSH2_MSG_KEXDH_INIT.");
+
+ /* generate and send 'e', client DH public key */
+ dh = dh_new_group1();
+ packet_start(SSH2_MSG_KEXDH_INIT);
+ packet_put_bignum2(dh->pub_key);
+ packet_send();
+ packet_write_wait();
+
+#ifdef DEBUG_KEXDH
+ fprintf(stderr, "\np= ");
+ bignum_print(dh->p);
+ fprintf(stderr, "\ng= ");
+ bignum_print(dh->g);
+ fprintf(stderr, "\npub= ");
+ bignum_print(dh->pub_key);
+ fprintf(stderr, "\n");
+ DHparams_print_fp(stderr, dh);
+#endif
+
+ debug("Wait SSH2_MSG_KEXDH_REPLY.");
+
+ packet_read_expect(&payload_len, SSH2_MSG_KEXDH_REPLY);
+
+ debug("Got SSH2_MSG_KEXDH_REPLY.");
+
+ /* key, cert */
+ server_host_key_blob = packet_get_string(&sbloblen);
+ server_host_key = dsa_key_from_blob(server_host_key_blob, sbloblen);
+ if (server_host_key == NULL)
+ fatal("cannot decode server_host_key_blob");
+
+ check_host_key(host, hostaddr, server_host_key,
+ options.user_hostfile2, options.system_hostfile2);
+
+ /* DH paramter f, server public DH key */
+ dh_server_pub = BN_new();
+ if (dh_server_pub == NULL)
+ fatal("dh_server_pub == NULL");
+ packet_get_bignum2(dh_server_pub, &dlen);
+
+#ifdef DEBUG_KEXDH
+ fprintf(stderr, "\ndh_server_pub= ");
+ bignum_print(dh_server_pub);
+ fprintf(stderr, "\n");
+ debug("bits %d", BN_num_bits(dh_server_pub));
+#endif
+
+ /* signed H */
+ signature = packet_get_string(&slen);
+ packet_done();
+
+ if (!dh_pub_is_valid(dh, dh_server_pub))
+ packet_disconnect("bad server public DH value");
+
+ klen = DH_size(dh);
+ kbuf = xmalloc(klen);
+ kout = DH_compute_key(kbuf, dh_server_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);
+
+ /* calc and verify H */
+ 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),
+ server_host_key_blob, sbloblen,
+ dh->pub_key,
+ dh_server_pub,
+ shared_secret
+ );
+ xfree(server_host_key_blob);
+ buffer_free(client_kexinit);
+ buffer_free(server_kexinit);
+ xfree(client_kexinit);
+ xfree(server_kexinit);
+#ifdef DEBUG_KEXDH
+ fprintf(stderr, "hash == ");
+ for (i = 0; i< 20; i++)
+ fprintf(stderr, "%02x", (hash[i])&0xff);
+ fprintf(stderr, "\n");
+#endif
+ if (dsa_verify(server_host_key, (unsigned char *)signature, slen, hash, 20) != 1)
+ fatal("dsa_verify failed for server_host_key");
+ key_free(server_host_key);
+
+ kex_derive_keys(kex, hash, shared_secret);
+ packet_set_kex(kex);
+
+ /* have keys, free DH */
+ DH_free(dh);
+
+ /* save session id */
+ session_id2_len = 20;
+ session_id2 = xmalloc(session_id2_len);
+ memcpy(session_id2, hash, session_id2_len);
+
+ debug("Wait SSH2_MSG_NEWKEYS.");
+ packet_read_expect(&payload_len, SSH2_MSG_NEWKEYS);
+ packet_done();
+ debug("GOT SSH2_MSG_NEWKEYS.");
+
+ debug("send SSH2_MSG_NEWKEYS.");
+ packet_start(SSH2_MSG_NEWKEYS);
+ packet_send();
+ packet_write_wait();
+ debug("done: send SSH2_MSG_NEWKEYS.");
+
+#ifdef DEBUG_KEXDH
+ /* send 1st encrypted/maced/compressed message */
+ packet_start(SSH2_MSG_IGNORE);
+ packet_put_cstring("markus");
+ packet_send();
+ packet_write_wait();
+#endif
+ debug("done: KEX2.");
+}
+/*
+ * Authenticate user
+ */
+int
+ssh2_try_passwd(const char *server_user, const char *host, const char *service)
+{
+ char prompt[80];
+ char *password;
+
+ snprintf(prompt, sizeof(prompt), "%.30s@%.40s's password: ",
+ server_user, host);
+ password = read_passphrase(prompt, 0);
+ packet_start(SSH2_MSG_USERAUTH_REQUEST);
+ packet_put_cstring(server_user);
+ packet_put_cstring(service);
+ packet_put_cstring("password");
+ packet_put_char(0);
+ packet_put_cstring(password);
+ memset(password, 0, strlen(password));
+ xfree(password);
+ packet_send();
+ packet_write_wait();
+ return 1;
+}
+
+int
+ssh2_try_pubkey(char *filename,
+ const char *server_user, const char *host, const char *service)
+{
+ Buffer b;
+ Key *k;
+ unsigned char *blob, *signature;
+ int bloblen, slen;
+
+ debug("try pubkey: %s", filename);
+
+ k = key_new(KEY_DSA);
+ if (!load_private_key(filename, "", k, NULL)) {
+ int success = 0;
+ char *passphrase;
+ char prompt[300];
+ snprintf(prompt, sizeof prompt,
+ "Enter passphrase for DSA key '%.100s': ",
+ filename);
+ passphrase = read_passphrase(prompt, 0);
+ success = load_private_key(filename, passphrase, k, NULL);
+ memset(passphrase, 0, strlen(passphrase));
+ xfree(passphrase);
+ if (!success)
+ return 0;
+ }
+ dsa_make_key_blob(k, &blob, &bloblen);
+
+ /* data to be signed */
+ buffer_init(&b);
+ buffer_append(&b, session_id2, session_id2_len);
+ buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
+ buffer_put_cstring(&b, server_user);
+ buffer_put_cstring(&b, service);
+ buffer_put_cstring(&b, "publickey");
+ buffer_put_char(&b, 1);
+ buffer_put_cstring(&b, KEX_DSS);
+ buffer_put_string(&b, blob, bloblen);
+ xfree(blob);
+
+ /* generate signature */
+ dsa_sign(k, &signature, &slen, buffer_ptr(&b), buffer_len(&b));
+ key_free(k);
+#ifdef DEBUG_DSS
+ buffer_dump(&b);
+#endif
+ /* append signature */
+ buffer_put_string(&b, signature, slen);
+ xfree(signature);
+
+ /* skip session id and packet type */
+ if (buffer_len(&b) < session_id2_len + 1)
+ fatal("ssh2_try_pubkey: internal error");
+ buffer_consume(&b, session_id2_len + 1);
+
+ /* put remaining data from buffer into packet */
+ packet_start(SSH2_MSG_USERAUTH_REQUEST);
+ packet_put_raw(buffer_ptr(&b), buffer_len(&b));
+ buffer_free(&b);
+
+ /* send */
+ packet_send();
+ packet_write_wait();
+ return 1;
+}
+
+void
+ssh_userauth2(const char *server_user, char *host)
+{
+ int type;
+ int plen;
+ int sent;
+ unsigned int dlen;
+ int partial;
+ int i = 0;
+ char *auths;
+ char *service = "ssh-connection"; /* service name */
+
+ debug("send SSH2_MSG_SERVICE_REQUEST");
+ packet_start(SSH2_MSG_SERVICE_REQUEST);
+ packet_put_cstring("ssh-userauth");
+ packet_send();
+ packet_write_wait();
+
+ type = packet_read(&plen);
+ if (type != SSH2_MSG_SERVICE_ACCEPT) {
+ fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type);
+ }
+ if (packet_remaining() > 0) {
+ char *reply = packet_get_string(&plen);
+ debug("service_accept: %s", reply);
+ xfree(reply);
+ } else {
+ /* payload empty for ssh-2.0.13 ?? */
+ log("buggy server: service_accept w/o service");
+ }
+ packet_done();
+ debug("got SSH2_MSG_SERVICE_ACCEPT");
+
+ /* INITIAL request for auth */
+ packet_start(SSH2_MSG_USERAUTH_REQUEST);
+ packet_put_cstring(server_user);
+ packet_put_cstring(service);
+ packet_put_cstring("none");
+ packet_send();
+ packet_write_wait();
+
+ for (;;) {
+ sent = 0;
+ type = packet_read(&plen);
+ if (type == SSH2_MSG_USERAUTH_SUCCESS)
+ break;
+ if (type != SSH2_MSG_USERAUTH_FAILURE)
+ fatal("access denied: %d", type);
+ /* SSH2_MSG_USERAUTH_FAILURE means: try again */
+ auths = packet_get_string(&dlen);
+ debug("authentications that can continue: %s", auths);
+ partial = packet_get_char();
+ packet_done();
+ if (partial)
+ debug("partial success");
+ if (options.rsa_authentication &&
+ strstr(auths, "publickey") != NULL) {
+ while (i < options.num_identity_files2) {
+ sent = ssh2_try_pubkey(
+ options.identity_files2[i++],
+ server_user, host, service);
+ if (sent)
+ break;
+ }
+ }
+ if (!sent) {
+ if (options.password_authentication &&
+ !options.batch_mode &&
+ strstr(auths, "password") != NULL) {
+ sent = ssh2_try_passwd(server_user, host, service);
+ }
+ }
+ if (!sent)
+ fatal("Permission denied (%s).", auths);
+ xfree(auths);
+ }
+ packet_done();
+ debug("ssh-userauth2 successfull");
+}