- markus@cvs.openbsd.org 2001/04/03 19:53:29
[dh.c dh.h kex.c kex.h sshconnect2.c sshd.c]
move kex to kex*.c, used dispatch_set() callbacks for kex. should
make rekeying easier.
diff --git a/ChangeLog b/ChangeLog
index df8ebde..0a84a52 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,10 @@
- stevesk@cvs.openbsd.org 2001/04/03 13:56:11
[sftp-glob.c ssh-agent.c ssh-keygen.c]
free() -> xfree()
+ - markus@cvs.openbsd.org 2001/04/03 19:53:29
+ [dh.c dh.h kex.c kex.h sshconnect2.c sshd.c]
+ move kex to kex*.c, used dispatch_set() callbacks for kex. should
+ make rekeying easier.
20010403
- OpenBSD CVS Sync
@@ -4816,4 +4820,4 @@
- Wrote replacements for strlcpy and mkdtemp
- Released 1.0pre1
-$Id: ChangeLog,v 1.1049 2001/04/04 01:53:20 mouring Exp $
+$Id: ChangeLog,v 1.1050 2001/04/04 01:56:17 mouring Exp $
diff --git a/dh.c b/dh.c
index 6c53b00..03b9fd1 100644
--- a/dh.c
+++ b/dh.c
@@ -23,7 +23,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: dh.c,v 1.11 2001/03/29 21:17:39 markus Exp $");
+RCSID("$OpenBSD: dh.c,v 1.12 2001/04/03 19:53:29 markus Exp $");
#include "xmalloc.h"
@@ -273,3 +273,22 @@
return (dh_new_group_asc(gen, group1));
}
+
+/*
+ * Estimates the group order for a Diffie-Hellman group that has an
+ * attack complexity approximately the same as O(2**bits). Estimate
+ * with: O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3)))
+ */
+
+int
+dh_estimate(int bits)
+{
+
+ if (bits < 64)
+ return (512); /* O(2**63) */
+ if (bits < 128)
+ return (1024); /* O(2**86) */
+ if (bits < 192)
+ return (2048); /* O(2**116) */
+ return (4096); /* O(2**156) */
+}
diff --git a/dh.h b/dh.h
index 13d2fa1..e8b2944 100644
--- a/dh.h
+++ b/dh.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: dh.h,v 1.4 2001/03/29 21:17:39 markus Exp $ */
+/* $OpenBSD: dh.h,v 1.5 2001/04/03 19:53:29 markus Exp $ */
/*
* Copyright (c) 2000 Niels Provos. All rights reserved.
@@ -40,6 +40,8 @@
void dh_gen_key(DH *, int);
int dh_pub_is_valid(DH *dh, BIGNUM *dh_pub);
+int dh_estimate(int bits);
+
#define DH_GRP_MIN 1024
#define DH_GRP_MAX 8192
diff --git a/kex.c b/kex.c
index 576d4b5..a0a5b46 100644
--- a/kex.c
+++ b/kex.c
@@ -23,12 +23,9 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: kex.c,v 1.25 2001/03/29 21:17:39 markus Exp $");
+RCSID("$OpenBSD: kex.c,v 1.26 2001/04/03 19:53:29 markus Exp $");
#include <openssl/crypto.h>
-#include <openssl/bio.h>
-#include <openssl/bn.h>
-#include <openssl/pem.h>
#include "ssh2.h"
#include "xmalloc.h"
@@ -42,233 +39,169 @@
#include "log.h"
#include "mac.h"
#include "match.h"
+#include "dispatch.h"
#define KEX_COOKIE_LEN 16
-Buffer *
-kex_init(char *myproposal[PROPOSAL_MAX])
+void kex_kexinit_finish(Kex *kex);
+void kex_choose_conf(Kex *k);
+
+/* put algorithm proposal into buffer */
+void
+kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX])
{
- int first_kex_packet_follows = 0;
- u_char cookie[KEX_COOKIE_LEN];
u_int32_t rand = 0;
int i;
- Buffer *ki = xmalloc(sizeof(*ki));
+
+ buffer_clear(b);
for (i = 0; i < KEX_COOKIE_LEN; i++) {
if (i % 4 == 0)
rand = arc4random();
- cookie[i] = rand & 0xff;
+ buffer_put_char(b, rand & 0xff);
rand >>= 8;
}
- buffer_init(ki);
- buffer_append(ki, (char *)cookie, sizeof cookie);
for (i = 0; i < PROPOSAL_MAX; i++)
- buffer_put_cstring(ki, myproposal[i]);
- buffer_put_char(ki, first_kex_packet_follows);
- buffer_put_int(ki, 0); /* uint32 reserved */
- return ki;
+ buffer_put_cstring(b, proposal[i]);
+ buffer_put_char(b, 0); /* first_kex_packet_follows */
+ buffer_put_int(b, 0); /* uint32 reserved */
}
-/* send kexinit, parse and save reply */
-void
-kex_exchange_kexinit(
- Buffer *my_kexinit, Buffer *peer_kexint,
- char *peer_proposal[PROPOSAL_MAX])
+/* parse buffer and return algorithm proposal */
+char **
+kex_buf2prop(Buffer *raw)
{
+ Buffer b;
int i;
- char *ptr;
- int plen;
+ char **proposal;
- debug("send KEXINIT");
- packet_start(SSH2_MSG_KEXINIT);
- packet_put_raw(buffer_ptr(my_kexinit), buffer_len(my_kexinit));
- packet_send();
- packet_write_wait();
- debug("done");
+ proposal = xmalloc(PROPOSAL_MAX * sizeof(char *));
- /*
- * read and save raw KEXINIT payload in buffer. this is used during
- * computation of the session_id and the session keys.
- */
- debug("wait KEXINIT");
- packet_read_expect(&plen, SSH2_MSG_KEXINIT);
- ptr = packet_get_raw(&plen);
- buffer_append(peer_kexint, ptr, plen);
-
- /* parse packet and save algorithm proposal */
+ buffer_init(&b);
+ buffer_append(&b, buffer_ptr(raw), buffer_len(raw));
/* skip cookie */
for (i = 0; i < KEX_COOKIE_LEN; i++)
- packet_get_char();
+ buffer_get_char(&b);
/* extract kex init proposal strings */
for (i = 0; i < PROPOSAL_MAX; i++) {
- peer_proposal[i] = packet_get_string(NULL);
- debug("got kexinit: %s", peer_proposal[i]);
+ proposal[i] = buffer_get_string(&b,NULL);
+ debug2("kex_parse_kexinit: %s", proposal[i]);
}
- /* first kex follow / reserved */
- i = packet_get_char();
- debug("first kex follow: %d ", i);
- i = packet_get_int();
- debug("reserved: %d ", i);
- packet_done();
- debug("done");
+ /* first kex follows / reserved */
+ i = buffer_get_char(&b);
+ debug2("kex_parse_kexinit: first_kex_follows %d ", i);
+ i = buffer_get_int(&b);
+ debug2("kex_parse_kexinit: reserved %d ", i);
+ buffer_free(&b);
+ return proposal;
}
-#ifdef DEBUG_KEX
void
-dump_digest(u_char *digest, int len)
+kex_prop_free(char **proposal)
{
int i;
- for (i = 0; i< len; i++){
- fprintf(stderr, "%02x", digest[i]);
- if(i%2!=0)
- fprintf(stderr, " ");
- }
- fprintf(stderr, "\n");
-}
-#endif
-u_char *
-kex_hash(
- char *client_version_string,
- char *server_version_string,
- char *ckexinit, int ckexinitlen,
- char *skexinit, int skexinitlen,
- char *serverhostkeyblob, int sbloblen,
- BIGNUM *client_dh_pub,
- BIGNUM *server_dh_pub,
- BIGNUM *shared_secret)
-{
- Buffer b;
- static u_char digest[EVP_MAX_MD_SIZE];
- EVP_MD *evp_md = EVP_sha1();
- EVP_MD_CTX md;
-
- buffer_init(&b);
- buffer_put_string(&b, client_version_string, strlen(client_version_string));
- buffer_put_string(&b, server_version_string, strlen(server_version_string));
-
- /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
- buffer_put_int(&b, ckexinitlen+1);
- buffer_put_char(&b, SSH2_MSG_KEXINIT);
- buffer_append(&b, ckexinit, ckexinitlen);
- buffer_put_int(&b, skexinitlen+1);
- buffer_put_char(&b, SSH2_MSG_KEXINIT);
- buffer_append(&b, skexinit, skexinitlen);
-
- buffer_put_string(&b, serverhostkeyblob, sbloblen);
- buffer_put_bignum2(&b, client_dh_pub);
- buffer_put_bignum2(&b, server_dh_pub);
- buffer_put_bignum2(&b, shared_secret);
-
-#ifdef DEBUG_KEX
- buffer_dump(&b);
-#endif
-
- EVP_DigestInit(&md, evp_md);
- EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
- EVP_DigestFinal(&md, digest, NULL);
-
- buffer_free(&b);
-
-#ifdef DEBUG_KEX
- dump_digest(digest, evp_md->md_size);
-#endif
- return digest;
+ for (i = 0; i < PROPOSAL_MAX; i++)
+ xfree(proposal[i]);
+ xfree(proposal);
}
-u_char *
-kex_hash_gex(
- char *client_version_string,
- char *server_version_string,
- char *ckexinit, int ckexinitlen,
- char *skexinit, int skexinitlen,
- char *serverhostkeyblob, int sbloblen,
- int min, int wantbits, int max, BIGNUM *prime, BIGNUM *gen,
- BIGNUM *client_dh_pub,
- BIGNUM *server_dh_pub,
- BIGNUM *shared_secret)
+void
+kex_protocol_error(int type, int plen, void *ctxt)
{
- Buffer b;
- static u_char digest[EVP_MAX_MD_SIZE];
- EVP_MD *evp_md = EVP_sha1();
- EVP_MD_CTX md;
-
- buffer_init(&b);
- buffer_put_string(&b, client_version_string, strlen(client_version_string));
- buffer_put_string(&b, server_version_string, strlen(server_version_string));
-
- /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
- buffer_put_int(&b, ckexinitlen+1);
- buffer_put_char(&b, SSH2_MSG_KEXINIT);
- buffer_append(&b, ckexinit, ckexinitlen);
- buffer_put_int(&b, skexinitlen+1);
- buffer_put_char(&b, SSH2_MSG_KEXINIT);
- buffer_append(&b, skexinit, skexinitlen);
-
- buffer_put_string(&b, serverhostkeyblob, sbloblen);
- if (min == -1 || max == -1)
- buffer_put_int(&b, wantbits);
- else {
- buffer_put_int(&b, min);
- buffer_put_int(&b, wantbits);
- buffer_put_int(&b, max);
- }
- buffer_put_bignum2(&b, prime);
- buffer_put_bignum2(&b, gen);
- buffer_put_bignum2(&b, client_dh_pub);
- buffer_put_bignum2(&b, server_dh_pub);
- buffer_put_bignum2(&b, shared_secret);
-
-#ifdef DEBUG_KEX
- buffer_dump(&b);
-#endif
-
- EVP_DigestInit(&md, evp_md);
- EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
- EVP_DigestFinal(&md, digest, NULL);
-
- buffer_free(&b);
-
-#ifdef DEBUG_KEX
- dump_digest(digest, evp_md->md_size);
-#endif
- return digest;
+ error("Hm, kex protocol error: type %d plen %d", type, plen);
}
-u_char *
-derive_key(int id, int need, u_char *hash, BIGNUM *shared_secret)
+void
+kex_send_newkeys(void)
{
- Buffer b;
- EVP_MD *evp_md = EVP_sha1();
- EVP_MD_CTX md;
- char c = id;
- int have;
- int mdsz = evp_md->md_size;
- u_char *digest = xmalloc(((need+mdsz-1)/mdsz)*mdsz);
+ packet_start(SSH2_MSG_NEWKEYS);
+ packet_send();
+ /* packet_write_wait(); */
+ debug("SSH2_MSG_NEWKEYS sent");
+}
- buffer_init(&b);
- buffer_put_bignum2(&b, shared_secret);
+void
+kex_input_newkeys(int type, int plen, void *ctxt)
+{
+ Kex *kex = ctxt;
+ int i;
- EVP_DigestInit(&md, evp_md);
- EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); /* shared_secret K */
- EVP_DigestUpdate(&md, hash, mdsz); /* transport-06 */
- EVP_DigestUpdate(&md, &c, 1); /* key id */
- EVP_DigestUpdate(&md, hash, mdsz); /* session id */
- EVP_DigestFinal(&md, digest, NULL);
+ debug("SSH2_MSG_NEWKEYS received");
+ kex->newkeys = 1;
+ for (i = 30; i <= 49; i++)
+ dispatch_set(i, &kex_protocol_error);
+ buffer_clear(&kex->peer);
+ buffer_clear(&kex->my);
+ kex->flags &= ~KEX_INIT_SENT;
+}
- /* expand */
- for (have = mdsz; need > have; have += mdsz) {
- EVP_DigestInit(&md, evp_md);
- EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
- EVP_DigestUpdate(&md, hash, mdsz);
- EVP_DigestUpdate(&md, digest, have);
- EVP_DigestFinal(&md, digest + have, NULL);
+void
+kex_send_kexinit(Kex *kex)
+{
+ packet_start(SSH2_MSG_KEXINIT);
+ packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my));
+ packet_send();
+ debug("SSH2_MSG_KEXINIT sent");
+ kex->flags |= KEX_INIT_SENT;
+}
+
+void
+kex_input_kexinit(int type, int plen, void *ctxt)
+{
+ char *ptr;
+ int dlen;
+ Kex *kex = (Kex *)ctxt;
+
+ dispatch_set(SSH2_MSG_KEXINIT, &kex_protocol_error);
+ debug("SSH2_MSG_KEXINIT received");
+
+ ptr = packet_get_raw(&dlen);
+ buffer_append(&kex->peer, ptr, dlen);
+
+ kex_kexinit_finish(kex);
+}
+
+Kex *
+kex_start(char *proposal[PROPOSAL_MAX])
+{
+ Kex *kex;
+ int i;
+
+ kex = xmalloc(sizeof(*kex));
+ memset(kex, 0, sizeof(*kex));
+ buffer_init(&kex->peer);
+ buffer_init(&kex->my);
+ kex_prop2buf(&kex->my, proposal);
+ kex->newkeys = 0;
+
+ kex_send_kexinit(kex); /* we start */
+ /* Numbers 30-49 are used for kex packets */
+ for (i = 30; i <= 49; i++)
+ dispatch_set(i, kex_protocol_error);
+
+ dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
+ dispatch_set(SSH2_MSG_NEWKEYS, &kex_input_newkeys);
+ return kex;
+}
+
+void
+kex_kexinit_finish(Kex *kex)
+{
+ if (!(kex->flags & KEX_INIT_SENT))
+ kex_send_kexinit(kex);
+
+ kex_choose_conf(kex);
+
+ switch(kex->kex_type) {
+ case DH_GRP1_SHA1:
+ kexdh(kex);
+ break;
+ case DH_GEX_SHA1:
+ kexgex(kex);
+ break;
+ default:
+ fatal("Unsupported key exchange %d", kex->kex_type);
}
- buffer_free(&b);
-#ifdef DEBUG_KEX
- fprintf(stderr, "Digest '%c'== ", c);
- dump_digest(digest, need);
-#endif
- return digest;
}
void
@@ -340,17 +273,25 @@
xfree(hostkeyalg);
}
-Kex *
-kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server)
+void
+kex_choose_conf(Kex *k)
{
+ char **my, **peer;
+ char **cprop, **sprop;
int mode;
int ctos; /* direction: if true client-to-server */
int need;
- Kex *k;
- k = xmalloc(sizeof(*k));
- memset(k, 0, sizeof(*k));
- k->server = server;
+ my = kex_buf2prop(&k->my);
+ peer = kex_buf2prop(&k->peer);
+
+ if (k->server) {
+ cprop=peer;
+ sprop=my;
+ } else {
+ cprop=my;
+ sprop=peer;
+ }
for (mode = 0; mode < MODE_MAX; mode++) {
int nenc, nmac, ncomp;
@@ -381,11 +322,51 @@
}
/* XXX need runden? */
k->we_need = need;
- return k;
+
+ kex_prop_free(my);
+ kex_prop_free(peer);
+
+}
+
+u_char *
+derive_key(int id, int need, u_char *hash, BIGNUM *shared_secret)
+{
+ Buffer b;
+ EVP_MD *evp_md = EVP_sha1();
+ EVP_MD_CTX md;
+ char c = id;
+ int have;
+ int mdsz = evp_md->md_size;
+ u_char *digest = xmalloc(((need+mdsz-1)/mdsz)*mdsz);
+
+ buffer_init(&b);
+ buffer_put_bignum2(&b, shared_secret);
+
+ EVP_DigestInit(&md, evp_md);
+ EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); /* shared_secret K */
+ EVP_DigestUpdate(&md, hash, mdsz); /* transport-06 */
+ EVP_DigestUpdate(&md, &c, 1); /* key id */
+ EVP_DigestUpdate(&md, hash, mdsz); /* session id */
+ EVP_DigestFinal(&md, digest, NULL);
+
+ /* expand */
+ for (have = mdsz; need > have; have += mdsz) {
+ EVP_DigestInit(&md, evp_md);
+ EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
+ EVP_DigestUpdate(&md, hash, mdsz);
+ EVP_DigestUpdate(&md, digest, have);
+ EVP_DigestFinal(&md, digest + have, NULL);
+ }
+ buffer_free(&b);
+#ifdef DEBUG_KEX
+ fprintf(stderr, "key '%c'== ", c);
+ dump_digest("key", digest, need);
+#endif
+ return digest;
}
#define NKEYS 6
-int
+void
kex_derive_keys(Kex *k, u_char *hash, BIGNUM *shared_secret)
{
int i;
@@ -402,5 +383,22 @@
k->enc[mode].key = keys[ctos ? 2 : 3];
k->mac[mode].key = keys[ctos ? 4 : 5];
}
- return 0;
}
+
+#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
+void
+dump_digest(char *msg, u_char *digest, int len)
+{
+ int i;
+
+ fprintf(stderr, "%s\n", msg);
+ for (i = 0; i< len; i++){
+ fprintf(stderr, "%02x", digest[i]);
+ if (i%32 == 31)
+ fprintf(stderr, "\n");
+ else if (i%8 == 7)
+ fprintf(stderr, " ");
+ }
+ fprintf(stderr, "\n");
+}
+#endif
diff --git a/kex.h b/kex.h
index 4cc87d5..58f6d82 100644
--- a/kex.h
+++ b/kex.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.h,v 1.17 2001/03/29 21:17:40 markus Exp $ */
+/* $OpenBSD: kex.h,v 1.18 2001/04/03 19:53:29 markus Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
@@ -28,6 +28,8 @@
#include <openssl/evp.h>
#include "buffer.h"
+#include "cipher.h"
+#include "key.h"
#define KEX_DH1 "diffie-hellman-group1-sha1"
#define KEX_DHGEX "diffie-hellman-group-exchange-sha1"
@@ -82,6 +84,7 @@
int enabled;
char *name;
};
+#define KEX_INIT_SENT 0x0001
struct Kex {
Enc enc [MODE_MAX];
Mac mac [MODE_MAX];
@@ -91,40 +94,31 @@
char *name;
int hostkey_type;
int kex_type;
+
+ /* used during kex */
+ Buffer my;
+ Buffer peer;
+ int newkeys;
+ int flags;
+ void *state;
+ char *client_version_string;
+ char *server_version_string;
+
+ int (*check_host_key)(Key *hostkey);
+ Key *(*load_host_key)(int type);
};
-Buffer *kex_init(char *myproposal[PROPOSAL_MAX]);
-void
-kex_exchange_kexinit(
- Buffer *my_kexinit, Buffer *peer_kexint,
- char *peer_proposal[PROPOSAL_MAX]);
-Kex *
-kex_choose_conf(char *cprop[PROPOSAL_MAX],
- char *sprop[PROPOSAL_MAX], int server);
-int kex_derive_keys(Kex *k, u_char *hash, BIGNUM *shared_secret);
+void kex_derive_keys(Kex *k, u_char *hash, BIGNUM *shared_secret);
void packet_set_kex(Kex *k);
+Kex *kex_start(char *proposal[PROPOSAL_MAX]);
+void kex_send_newkeys(void);
+void kex_protocol_error(int type, int plen, void *ctxt);
-u_char *
-kex_hash(
- char *client_version_string,
- char *server_version_string,
- char *ckexinit, int ckexinitlen,
- char *skexinit, int skexinitlen,
- char *serverhostkeyblob, int sbloblen,
- BIGNUM *client_dh_pub,
- BIGNUM *server_dh_pub,
- BIGNUM *shared_secret);
+void kexdh(Kex *);
+void kexgex(Kex *);
-u_char *
-kex_hash_gex(
- char *client_version_string,
- char *server_version_string,
- char *ckexinit, int ckexinitlen,
- char *skexinit, int skexinitlen,
- char *serverhostkeyblob, int sbloblen,
- int min, int wantbits, int max,
- BIGNUM *prime, BIGNUM *gen,
- BIGNUM *client_dh_pub,
- BIGNUM *server_dh_pub,
- BIGNUM *shared_secret);
+#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
+void dump_digest(char *msg, u_char *digest, int len);
+#endif
+
#endif
diff --git a/sshconnect2.c b/sshconnect2.c
index 460d614..4ed39a2 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -23,7 +23,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: sshconnect2.c,v 1.60 2001/03/29 21:06:21 stevesk Exp $");
+RCSID("$OpenBSD: sshconnect2.c,v 1.61 2001/04/03 19:53:29 markus Exp $");
#include <openssl/bn.h>
#include <openssl/md5.h>
@@ -47,15 +47,12 @@
#include "authfile.h"
#include "cli.h"
#include "dh.h"
-#include "dispatch.h"
#include "authfd.h"
#include "log.h"
#include "readconf.h"
#include "readpass.h"
#include "match.h"
-
-void ssh_dh1_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *);
-void ssh_dhgex_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *);
+#include "dispatch.h"
/* import */
extern char *client_version_string;
@@ -69,13 +66,24 @@
u_char *session_id2 = NULL;
int session_id2_len = 0;
+char *xxx_host;
+struct sockaddr *xxx_hostaddr;
+
+int
+check_host_key_callback(Key *hostkey)
+{
+ check_host_key(xxx_host, xxx_hostaddr, hostkey,
+ options.user_hostfile2, options.system_hostfile2);
+ return 0;
+}
+
void
ssh_kex2(char *host, struct sockaddr *hostaddr)
{
- int i, plen;
Kex *kex;
- Buffer *client_kexinit, *server_kexinit;
- char *sprop[PROPOSAL_MAX];
+
+ xxx_host = host;
+ xxx_hostaddr = hostaddr;
if (options.ciphers == (char *)-1) {
log("No valid ciphers for protocol version 2 given, using defaults.");
@@ -101,46 +109,13 @@
myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
}
- /* buffers with raw kexinit messages */
- server_kexinit = xmalloc(sizeof(*server_kexinit));
- buffer_init(server_kexinit);
- client_kexinit = kex_init(myproposal);
+ kex = kex_start(myproposal);
+ kex->client_version_string=client_version_string;
+ kex->server_version_string=server_version_string;
+ kex->check_host_key=&check_host_key_callback;
- /* algorithm negotiation */
- kex_exchange_kexinit(client_kexinit, server_kexinit, sprop);
- kex = kex_choose_conf(myproposal, sprop, 0);
- for (i = 0; i < PROPOSAL_MAX; i++)
- xfree(sprop[i]);
-
- /* server authentication and session key agreement */
- switch(kex->kex_type) {
- case DH_GRP1_SHA1:
- ssh_dh1_client(kex, host, hostaddr,
- client_kexinit, server_kexinit);
- break;
- case DH_GEX_SHA1:
- ssh_dhgex_client(kex, host, hostaddr, client_kexinit,
- server_kexinit);
- break;
- default:
- fatal("Unsupported key exchange %d", kex->kex_type);
- }
-
- buffer_free(client_kexinit);
- buffer_free(server_kexinit);
- xfree(client_kexinit);
- xfree(server_kexinit);
-
- debug("Wait SSH2_MSG_NEWKEYS.");
- packet_read_expect(&plen, 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.");
+ /* start key exchange */
+ dispatch_run(DISPATCH_BLOCK, &kex->newkeys, kex);
#ifdef DEBUG_KEXDH
/* send 1st encrypted/maced/compressed message */
@@ -149,339 +124,7 @@
packet_send();
packet_write_wait();
#endif
- debug("done: KEX2.");
-}
-
-/* diffie-hellman-group1-sha1 */
-
-void
-ssh_dh1_client(Kex *kex, char *host, struct sockaddr *hostaddr,
- Buffer *client_kexinit, Buffer *server_kexinit)
-{
-#ifdef DEBUG_KEXDH
- int i;
-#endif
- int plen, dlen;
- u_int klen, kout;
- char *signature = NULL;
- u_int slen;
- char *server_host_key_blob = NULL;
- Key *server_host_key;
- u_int sbloblen;
- DH *dh;
- BIGNUM *dh_server_pub = 0;
- BIGNUM *shared_secret = 0;
- u_char *kbuf;
- u_char *hash;
-
- debug("Sending SSH2_MSG_KEXDH_INIT.");
- /* generate and send 'e', client DH public key */
- dh = dh_new_group1();
- dh_gen_key(dh, kex->we_need * 8);
- packet_start(SSH2_MSG_KEXDH_INIT);
- packet_put_bignum2(dh->pub_key);
- packet_send();
- packet_write_wait();
-
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\np= ");
- BN_print_fp(stderr, dh->p);
- fprintf(stderr, "\ng= ");
- BN_print_fp(stderr, dh->g);
- fprintf(stderr, "\npub= ");
- BN_print_fp(stderr, dh->pub_key);
- fprintf(stderr, "\n");
- DHparams_print_fp(stderr, dh);
-#endif
-
- debug("Wait SSH2_MSG_KEXDH_REPLY.");
-
- packet_read_expect(&plen, SSH2_MSG_KEXDH_REPLY);
-
- debug("Got SSH2_MSG_KEXDH_REPLY.");
-
- /* key, cert */
- server_host_key_blob = packet_get_string(&sbloblen);
- server_host_key = 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= ");
- BN_print_fp(stderr, 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);
- DH_free(dh);
- BN_free(dh_server_pub);
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "hash == ");
- for (i = 0; i< 20; i++)
- fprintf(stderr, "%02x", (hash[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- if (key_verify(server_host_key, (u_char *)signature, slen, hash, 20) != 1)
- fatal("key_verify failed for server_host_key");
- key_free(server_host_key);
- xfree(signature);
-
- kex_derive_keys(kex, hash, shared_secret);
- BN_clear_free(shared_secret);
- packet_set_kex(kex);
-
- /* save session id */
- session_id2_len = 20;
- session_id2 = xmalloc(session_id2_len);
- memcpy(session_id2, hash, session_id2_len);
-}
-
-/* diffie-hellman-group-exchange-sha1 */
-
-/*
- * Estimates the group order for a Diffie-Hellman group that has an
- * attack complexity approximately the same as O(2**bits). Estimate
- * with: O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3)))
- */
-
-int
-dh_estimate(int bits)
-{
-
- if (bits < 64)
- return (512); /* O(2**63) */
- if (bits < 128)
- return (1024); /* O(2**86) */
- if (bits < 192)
- return (2048); /* O(2**116) */
- return (4096); /* O(2**156) */
-}
-
-void
-ssh_dhgex_client(Kex *kex, char *host, struct sockaddr *hostaddr,
- Buffer *client_kexinit, Buffer *server_kexinit)
-{
-#ifdef DEBUG_KEXDH
- int i;
-#endif
- int plen, dlen;
- u_int klen, kout;
- char *signature = NULL;
- u_int slen, nbits, min, max;
- char *server_host_key_blob = NULL;
- Key *server_host_key;
- u_int sbloblen;
- DH *dh;
- BIGNUM *dh_server_pub = 0;
- BIGNUM *shared_secret = 0;
- BIGNUM *p = 0, *g = 0;
- u_char *kbuf;
- u_char *hash;
-
- nbits = dh_estimate(kex->we_need * 8);
-
- if (datafellows & SSH_OLD_DHGEX) {
- debug("Sending SSH2_MSG_KEX_DH_GEX_REQUEST_OLD.");
-
- /* Old GEX request */
- packet_start(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD);
- packet_put_int(nbits);
- min = DH_GRP_MIN;
- max = DH_GRP_MAX;
- } else {
- debug("Sending SSH2_MSG_KEX_DH_GEX_REQUEST.");
-
- /* New GEX request */
- min = DH_GRP_MIN;
- max = DH_GRP_MAX;
-
- packet_start(SSH2_MSG_KEX_DH_GEX_REQUEST);
- packet_put_int(min);
- packet_put_int(nbits);
- packet_put_int(max);
- }
- packet_send();
- packet_write_wait();
-
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\nmin = %d, nbits = %d, max = %d", min, nbits, max);
-#endif
-
- debug("Wait SSH2_MSG_KEX_DH_GEX_GROUP.");
-
- packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_GROUP);
-
- debug("Got SSH2_MSG_KEX_DH_GEX_GROUP.");
-
- if ((p = BN_new()) == NULL)
- fatal("BN_new");
- packet_get_bignum2(p, &dlen);
- if ((g = BN_new()) == NULL)
- fatal("BN_new");
- packet_get_bignum2(g, &dlen);
-
- if (BN_num_bits(p) < min || BN_num_bits(p) > max)
- fatal("DH_GEX group out of range: %d !< %d !< %d",
- min, BN_num_bits(p), max);
-
- dh = dh_new_group(g, p);
-
- dh_gen_key(dh, kex->we_need * 8);
-
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\np= ");
- BN_print_fp(stderr, dh->p);
- fprintf(stderr, "\ng= ");
- BN_print_fp(stderr, dh->g);
- fprintf(stderr, "\npub= ");
- BN_print_fp(stderr, dh->pub_key);
- fprintf(stderr, "\n");
- DHparams_print_fp(stderr, dh);
-#endif
-
- debug("Sending SSH2_MSG_KEX_DH_GEX_INIT.");
- /* generate and send 'e', client DH public key */
- packet_start(SSH2_MSG_KEX_DH_GEX_INIT);
- packet_put_bignum2(dh->pub_key);
- packet_send();
- packet_write_wait();
-
- debug("Wait SSH2_MSG_KEX_DH_GEX_REPLY.");
-
- packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_REPLY);
-
- debug("Got SSH2_MSG_KEXDH_REPLY.");
-
- /* key, cert */
- server_host_key_blob = packet_get_string(&sbloblen);
- server_host_key = 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= ");
- BN_print_fp(stderr, 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);
-
- if (datafellows & SSH_OLD_DHGEX) {
- /* These values are not included in the hash */
- min = -1;
- max = -1;
- }
-
- /* calc and verify H */
- 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),
- server_host_key_blob, sbloblen,
- min, nbits, max,
- dh->p, dh->g,
- dh->pub_key,
- dh_server_pub,
- shared_secret
- );
- xfree(server_host_key_blob);
- DH_free(dh);
- BN_free(dh_server_pub);
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "hash == ");
- for (i = 0; i< 20; i++)
- fprintf(stderr, "%02x", (hash[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- if (key_verify(server_host_key, (u_char *)signature, slen, hash, 20) != 1)
- fatal("key_verify failed for server_host_key");
- key_free(server_host_key);
- xfree(signature);
-
- kex_derive_keys(kex, hash, shared_secret);
- BN_clear_free(shared_secret);
- packet_set_kex(kex);
-
- /* save session id */
- session_id2_len = 20;
- session_id2 = xmalloc(session_id2_len);
- memcpy(session_id2, hash, session_id2_len);
+ debug("done: ssh_kex2.");
}
/*
@@ -563,6 +206,7 @@
Authctxt authctxt;
int type;
int plen;
+ int i;
if (options.challenge_reponse_authentication)
options.kbd_interactive_authentication = 1;
@@ -603,7 +247,10 @@
/* initial userauth request */
userauth_none(&authctxt);
- dispatch_init(&input_userauth_error);
+ //dispatch_init(&input_userauth_error);
+ for (i = 50; i <= 254; i++) {
+ dispatch_set(i, &input_userauth_error);
+ }
dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
diff --git a/sshd.c b/sshd.c
index b5e2d0f..c546759 100644
--- a/sshd.c
+++ b/sshd.c
@@ -40,7 +40,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.185 2001/03/29 23:42:01 djm Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.186 2001/04/03 19:53:29 markus Exp $");
#include <openssl/dh.h>
#include <openssl/bn.h>
@@ -70,6 +70,7 @@
#include "canohost.h"
#include "auth.h"
#include "misc.h"
+#include "dispatch.h"
#ifdef LIBWRAP
#include <tcpd.h>
@@ -1407,14 +1408,7 @@
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] =
@@ -1431,36 +1425,14 @@
}
myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
- server_kexinit = kex_init(myproposal);
- client_kexinit = xmalloc(sizeof(*client_kexinit));
- buffer_init(client_kexinit);
+ kex = kex_start(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]);
-
- 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);
- }
-
- 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.");
+ /* start key exchange */
+ dispatch_run(DISPATCH_BLOCK, &kex->newkeys, kex);
#ifdef DEBUG_KEXDH
/* send 1st encrypted/maced/compressed message */
@@ -1469,316 +1441,5 @@
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, kex->we_need * 8);
-
- 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, type, min, max;
- 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.");
- type = packet_read(&payload_len);
- if (type != SSH2_MSG_KEX_DH_GEX_REQUEST_OLD &&
- type != SSH2_MSG_KEX_DH_GEX_REQUEST)
- packet_disconnect("Protocol error: expected type %d or %d, got %d",
- SSH2_MSG_KEX_DH_GEX_REQUEST_OLD,
- SSH2_MSG_KEX_DH_GEX_REQUEST,
- type);
- if (type == SSH2_MSG_KEX_DH_GEX_REQUEST_OLD) {
- nbits = packet_get_int();
- min = DH_GRP_MIN;
- max = DH_GRP_MAX;
- } else {
- min = packet_get_int();
- nbits = packet_get_int();
- max = packet_get_int();
-
- min = MAX(DH_GRP_MIN, min);
- max = MIN(DH_GRP_MAX, max);
- }
-
- if (max < min || nbits < min || max < nbits)
- fatal("DH_GEX_REQUEST, bad parameters: %d !< %d !< %d",
- min, nbits, max);
-
- dh = choose_dh(min, nbits, max);
- if (dh == NULL)
- packet_disconnect("Protocol error: no matching DH grp found");
-
- 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, kex->we_need * 8);
-
- 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);
-
- if (type == SSH2_MSG_KEX_DH_GEX_REQUEST_OLD) {
- /* These values are not included in the hash */
- min = -1;
- max = -1;
- }
-
- /* 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,
- min, nbits, max,
- 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");
}