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forgot -kb, remove openssl/ssl conditional

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This commit is contained in:
Damien Miller 2000-04-16 11:52:47 +10:00
parent d8495e7d61
commit a664e870f2
3 changed files with 781 additions and 0 deletions
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298
dsa.c Normal file
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/*
* 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("$Id: dsa.c,v 1.4 2000/04/14 10:30:31 markus Exp $");
#include "ssh.h"
#include "xmalloc.h"
#include "buffer.h"
#include "bufaux.h"
#include "compat.h"
#include <openssl/bn.h>
#include <openssl/dh.h>
#include <openssl/rsa.h>
#include <openssl/dsa.h>
#include <openssl/evp.h>
#include <openssl/bio.h>
#include <openssl/pem.h>
#include <openssl/hmac.h>
#include "kex.h"
#include "key.h"
#define INTBLOB_LEN 20
#define SIGBLOB_LEN (2*INTBLOB_LEN)
Key *
dsa_serverkey_from_blob(
char *serverhostkey, int serverhostkeylen)
{
Buffer b;
char *ktype;
int rlen;
DSA *dsa;
Key *key;
/* fetch & parse DSA/DSS pubkey */
key = key_new(KEY_DSA);
dsa = key->dsa;
buffer_init(&b);
buffer_append(&b, serverhostkey, serverhostkeylen);
ktype = buffer_get_string(&b, NULL);
if (strcmp(KEX_DSS, ktype) != 0) {
error("dsa_serverkey_from_blob: cannot handle type %s", ktype);
key_free(key);
return NULL;
}
buffer_get_bignum2(&b, dsa->p);
buffer_get_bignum2(&b, dsa->q);
buffer_get_bignum2(&b, dsa->g);
buffer_get_bignum2(&b, dsa->pub_key);
rlen = buffer_len(&b);
if(rlen != 0)
error("dsa_serverkey_from_blob: remaining bytes in serverhostkey %d", rlen);
buffer_free(&b);
debug("keytype %s", ktype);
#ifdef DEBUG_DSS
DSA_print_fp(stderr, dsa, 8);
#endif
return key;
}
DSA *
dsa_load_private(char *filename)
{
DSA *dsa;
BIO *in;
in = BIO_new(BIO_s_file());
if (in == NULL)
fatal("BIO_new failed");
if (BIO_read_filename(in, filename) <= 0)
fatal("BIO_read failed %s: %s", filename, strerror(errno));
fprintf(stderr, "read DSA private key\n");
dsa = PEM_read_bio_DSAPrivateKey(in,NULL,NULL,NULL);
if (dsa == NULL)
fatal("PEM_read_bio_DSAPrivateKey failed %s", filename);
BIO_free(in);
return dsa;
}
Key *
dsa_get_serverkey(char *filename)
{
Key *k = key_new(KEY_EMPTY);
k->type = KEY_DSA;
k->dsa = dsa_load_private(filename);
#ifdef DEBUG_DSS
DSA_print_fp(stderr, dsa, 8);
#endif
return k;
}
int
dsa_make_serverkey_blob(Key *key, unsigned char **blobp, unsigned int *lenp)
{
Buffer b;
int len;
unsigned char *buf;
if (key == NULL || key->type != KEY_DSA)
return 0;
buffer_init(&b);
buffer_put_cstring(&b, KEX_DSS);
buffer_put_bignum2(&b, key->dsa->p);
buffer_put_bignum2(&b, key->dsa->q);
buffer_put_bignum2(&b, key->dsa->g);
buffer_put_bignum2(&b, key->dsa->pub_key);
len = buffer_len(&b);
buf = xmalloc(len);
memcpy(buf, buffer_ptr(&b), len);
memset(buffer_ptr(&b), 0, len);
buffer_free(&b);
if (lenp != NULL)
*lenp = len;
if (blobp != NULL)
*blobp = buf;
return len;
}
int
dsa_sign(
Key *key,
unsigned char **sigp, int *lenp,
unsigned char *hash, int hlen)
{
unsigned char *digest;
unsigned char *ret;
DSA_SIG *sig;
EVP_MD *evp_md = EVP_sha1();
EVP_MD_CTX md;
unsigned int rlen;
unsigned int slen;
unsigned int len;
unsigned char sigblob[SIGBLOB_LEN];
Buffer b;
if (key == NULL || key->type != KEY_DSA || key->dsa == NULL) {
error("dsa_sign: no DSA key");
return -1;
}
digest = xmalloc(evp_md->md_size);
EVP_DigestInit(&md, evp_md);
EVP_DigestUpdate(&md, hash, hlen);
EVP_DigestFinal(&md, digest, NULL);
sig = DSA_do_sign(digest, evp_md->md_size, key->dsa);
rlen = BN_num_bytes(sig->r);
slen = BN_num_bytes(sig->s);
if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) {
error("bad sig size %d %d", rlen, slen);
DSA_SIG_free(sig);
return -1;
}
debug("sig size %d %d", rlen, slen);
memset(sigblob, 0, SIGBLOB_LEN);
BN_bn2bin(sig->r, sigblob+ SIGBLOB_LEN - INTBLOB_LEN - rlen);
BN_bn2bin(sig->s, sigblob+ SIGBLOB_LEN - slen);
DSA_SIG_free(sig);
if (datafellows) {
debug("datafellows");
ret = xmalloc(SIGBLOB_LEN);
memcpy(ret, sigblob, SIGBLOB_LEN);
if (lenp != NULL)
*lenp = SIGBLOB_LEN;
if (sigp != NULL)
*sigp = ret;
} else {
/* ietf-drafts */
buffer_init(&b);
buffer_put_cstring(&b, KEX_DSS);
buffer_put_string(&b, sigblob, SIGBLOB_LEN);
len = buffer_len(&b);
ret = xmalloc(len);
memcpy(ret, buffer_ptr(&b), len);
buffer_free(&b);
if (lenp != NULL)
*lenp = len;
if (sigp != NULL)
*sigp = ret;
}
return 0;
}
int
dsa_verify(
Key *key,
unsigned char *signature, int signaturelen,
unsigned char *hash, int hlen)
{
Buffer b;
unsigned char *digest;
DSA_SIG *sig;
EVP_MD *evp_md = EVP_sha1();
EVP_MD_CTX md;
char *ktype;
unsigned char *sigblob;
char *txt;
unsigned int len;
int rlen;
int ret;
if (key == NULL || key->type != KEY_DSA || key->dsa == NULL) {
error("dsa_verify: no DSA key");
return -1;
}
if (datafellows && signaturelen != SIGBLOB_LEN) {
log("heh? datafellows ssh2 complies with ietf-drafts????");
datafellows = 0;
}
debug("len %d datafellows %d", signaturelen, datafellows);
/* fetch signature */
if (datafellows) {
sigblob = signature;
len = signaturelen;
} else {
/* ietf-drafts */
buffer_init(&b);
buffer_append(&b, (char *) signature, signaturelen);
ktype = buffer_get_string(&b, NULL);
sigblob = (unsigned char *)buffer_get_string(&b, &len);
rlen = buffer_len(&b);
if(rlen != 0)
error("remaining bytes in signature %d", rlen);
buffer_free(&b);
}
if (len != SIGBLOB_LEN) {
fatal("bad sigbloblen %d != SIGBLOB_LEN", len);
}
/* parse signature */
sig = DSA_SIG_new();
sig->r = BN_new();
sig->s = BN_new();
BN_bin2bn(sigblob, INTBLOB_LEN, sig->r);
BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s);
if (!datafellows) {
memset(sigblob, 0, len);
xfree(sigblob);
}
/* sha1 the signed data (== session_id == hash) */
digest = xmalloc(evp_md->md_size);
EVP_DigestInit(&md, evp_md);
EVP_DigestUpdate(&md, hash, hlen);
EVP_DigestFinal(&md, digest, NULL);
ret = DSA_do_verify(digest, evp_md->md_size, sig, key->dsa);
memset(digest, 0, evp_md->md_size);
xfree(digest);
DSA_SIG_free(sig);
switch (ret) {
case 1:
txt = "correct";
break;
case 0:
txt = "incorrect";
break;
case -1:
default:
txt = "error";
break;
}
debug("dsa_verify: signature %s", txt);
return ret;
}

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/*
* 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("$Id: hmac.c,v 1.2 2000/04/12 09:39:10 markus Exp $");
#include "xmalloc.h"
#include "ssh.h"
#include "getput.h"
#include <openssl/hmac.h>
unsigned char *
hmac(
EVP_MD *evp_md,
unsigned int seqno,
unsigned char *data, int datalen,
unsigned char *key, int keylen)
{
HMAC_CTX c;
static unsigned char m[EVP_MAX_MD_SIZE];
unsigned char b[4];
if (key == NULL)
fatal("hmac: no key");
HMAC_Init(&c, key, keylen, evp_md);
PUT_32BIT(b, seqno);
HMAC_Update(&c, b, sizeof b);
HMAC_Update(&c, data, datalen);
HMAC_Final(&c, m, NULL);
HMAC_cleanup(&c);
return(m);
}

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/*
* 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("$Id: kex.c,v 1.7 2000/04/16 01:52:47 damien Exp $");
#include "ssh.h"
#include "ssh2.h"
#include "xmalloc.h"
#include "buffer.h"
#include "bufaux.h"
#include "cipher.h"
#include "compat.h"
#include <openssl/bn.h>
#include <openssl/dh.h>
#include <openssl/crypto.h>
#include <openssl/bio.h>
#include <openssl/bn.h>
#include <openssl/dh.h>
#include <openssl/pem.h>
#include "kex.h"
Buffer *
kex_init(char *myproposal[PROPOSAL_MAX])
{
char c = 0;
unsigned char cookie[16];
u_int32_t rand = 0;
int i;
Buffer *ki = xmalloc(sizeof(*ki));
for (i = 0; i < 16; i++) {
if (i % 4 == 0)
rand = arc4random();
cookie[i] = 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_append(ki, &c, 1); /* boolean first_kex_packet_follows */
buffer_put_int(ki, 0); /* uint32 0 (reserved for future extension) */
return ki;
}
/* diffie-hellman-group1-sha1 */
int
dh_pub_is_valid(DH *dh, BIGNUM *dh_pub)
{
int i;
int n = BN_num_bits(dh_pub);
int bits_set = 0;
/* we only accept g==2 */
if (!BN_is_word(dh->g, 2)) {
log("invalid DH base != 2");
return 0;
}
if (dh_pub->neg) {
log("invalid public DH value: negativ");
return 0;
}
for (i = 0; i <= n; i++)
if (BN_is_bit_set(dh_pub, i))
bits_set++;
debug("bits set: %d/%d", bits_set, BN_num_bits(dh->p));
/* if g==2 and bits_set==1 then computing log_g(dh_pub) is trivial */
if (bits_set > 1 && (BN_cmp(dh_pub, dh->p) == -1))
return 1;
log("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p));
return 0;
}
DH *
dh_new_group1()
{
static char *group1 =
"FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
"29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
"EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
"E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
"EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE65381"
"FFFFFFFF" "FFFFFFFF";
DH *dh;
int ret, tries = 0;
dh = DH_new();
if(dh == NULL)
fatal("DH_new");
ret = BN_hex2bn(&dh->p, group1);
if(ret<0)
fatal("BN_hex2bn");
dh->g = BN_new();
if(dh->g == NULL)
fatal("DH_new g");
BN_set_word(dh->g, 2);
do {
if (DH_generate_key(dh) == 0)
fatal("DH_generate_key");
if (tries++ > 10)
fatal("dh_new_group1: too many bad keys: giving up");
} while (!dh_pub_is_valid(dh, dh->pub_key));
return dh;
}
void
bignum_print(BIGNUM *b)
{
BN_print_fp(stderr,b);
}
void
dump_digest(unsigned char *digest, int len)
{
int i;
for (i = 0; i< len; i++){
fprintf(stderr, "%02x", digest[i]);
if(i%2!=0)
fprintf(stderr, " ");
}
fprintf(stderr, "\n");
}
unsigned 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 unsigned 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;
}
unsigned char *
derive_key(int id, int need, char unsigned *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;
unsigned 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, "Digest '%c'== ", c);
dump_digest(digest, need);
#endif
return digest;
}
#define NKEYS 6
#define MAX_PROP 20
#define SEP ","
char *
get_match(char *client, char *server)
{
char *sproposals[MAX_PROP];
char *p;
int i, j, nproposals;
for ((p = strtok(server, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
if (i < MAX_PROP)
sproposals[i] = p;
else
break;
}
nproposals = i;
for ((p = strtok(client, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
for (j = 0; j < nproposals; j++)
if (strcmp(p, sproposals[j]) == 0)
return xstrdup(p);
}
return NULL;
}
void
choose_enc(Enc *enc, char *client, char *server)
{
char *name = get_match(client, server);
if (name == NULL)
fatal("no matching cipher found: client %s server %s", client, server);
enc->type = cipher_number(name);
switch (enc->type) {
case SSH_CIPHER_3DES_CBC:
enc->key_len = 24;
enc->iv_len = 8;
enc->block_size = 8;
break;
case SSH_CIPHER_BLOWFISH_CBC:
case SSH_CIPHER_CAST128_CBC:
enc->key_len = 16;
enc->iv_len = 8;
enc->block_size = 8;
break;
case SSH_CIPHER_ARCFOUR:
enc->key_len = 16;
enc->iv_len = 0;
enc->block_size = 8;
break;
default:
fatal("unsupported cipher %s", name);
}
enc->name = name;
enc->enabled = 0;
enc->iv = NULL;
enc->key = NULL;
}
void
choose_mac(Mac *mac, char *client, char *server)
{
char *name = get_match(client, server);
if (name == NULL)
fatal("no matching mac found: client %s server %s", client, server);
if (strcmp(name, "hmac-md5") == 0) {
mac->md = EVP_md5();
} else if (strcmp(name, "hmac-sha1") == 0) {
mac->md = EVP_sha1();
} else if (strcmp(name, "hmac-ripemd160@openssh.com") == 0) {
mac->md = EVP_ripemd160();
} else {
fatal("unsupported mac %s", name);
}
mac->name = name;
mac->mac_len = mac->md->md_size;
mac->key_len = datafellows ? 16 : mac->mac_len;
mac->key = NULL;
mac->enabled = 0;
}
void
choose_comp(Comp *comp, char *client, char *server)
{
char *name = get_match(client, server);
if (name == NULL)
fatal("no matching comp found: client %s server %s", client, server);
if (strcmp(name, "zlib") == 0) {
comp->type = 1;
} else if (strcmp(name, "none") == 0) {
comp->type = 0;
} else {
fatal("unsupported comp %s", name);
}
comp->name = name;
}
void
choose_kex(Kex *k, char *client, char *server)
{
k->name = get_match(client, server);
if (k->name == NULL)
fatal("no kex alg");
if (strcmp(k->name, KEX_DH1) != 0)
fatal("bad kex alg %s", k->name);
}
void
choose_hostkeyalg(Kex *k, char *client, char *server)
{
k->hostkeyalg = get_match(client, server);
if (k->hostkeyalg == NULL)
fatal("no hostkey alg");
if (strcmp(k->hostkeyalg, KEX_DSS) != 0)
fatal("bad hostkey alg %s", k->hostkeyalg);
}
Kex *
kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server)
{
int i;
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;
for (mode = 0; mode < MODE_MAX; mode++) {
int nenc, nmac, ncomp;
ctos = (!k->server && mode == MODE_OUT) || (k->server && mode == MODE_IN);
nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC;
nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC;
ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
choose_enc (&k->enc [mode], cprop[nenc], sprop[nenc]);
choose_mac (&k->mac [mode], cprop[nmac], sprop[nmac]);
choose_comp(&k->comp[mode], cprop[ncomp], sprop[ncomp]);
debug("kex: %s %s %s %s",
ctos ? "client->server" : "server->client",
k->enc[mode].name,
k->mac[mode].name,
k->comp[mode].name);
}
choose_kex(k, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
choose_hostkeyalg(k, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
for (i = 0; i < PROPOSAL_MAX; i++) {
xfree(cprop[i]);
xfree(sprop[i]);
}
need = 0;
for (mode = 0; mode < MODE_MAX; mode++) {
if (need < k->enc[mode].key_len)
need = k->enc[mode].key_len;
if (need < k->enc[mode].iv_len)
need = k->enc[mode].iv_len;
if (need < k->mac[mode].key_len)
need = k->mac[mode].key_len;
}
/* need runden? */
#define WE_NEED 32
k->we_need = WE_NEED;
k->we_need = need;
return k;
}
int
kex_derive_keys(Kex *k, unsigned char *hash, BIGNUM *shared_secret)
{
int i;
int mode;
int ctos;
unsigned char *keys[NKEYS];
for (i = 0; i < NKEYS; i++)
keys[i] = derive_key('A'+i, k->we_need, hash, shared_secret);
for (mode = 0; mode < MODE_MAX; mode++) {
ctos = (!k->server && mode == MODE_OUT) || (k->server && mode == MODE_IN);
k->enc[mode].iv = keys[ctos ? 0 : 1];
k->enc[mode].key = keys[ctos ? 2 : 3];
k->mac[mode].key = keys[ctos ? 4 : 5];
}
return 0;
}