/* Select fallback group used by DH-GEX if moduli file cannot be read. */
DH *
dh_new_group_fallback(int max)
{
debug3("%s: requested max size %d", __func__, max);
if (max < 3072) {
debug3("using 2k bit group 14");
return dh_new_group14();
} else if (max < 6144) {
debug3("using 4k bit group 16");
return dh_new_group16();
}
debug3("using 8k bit group 18");
return dh_new_group18();
}
int
kexdh_client(struct ssh *ssh)
{
struct kex *kex = ssh->kex;
int r;
/* generate and send 'e', client DH public key */
switch (kex->kex_type) {
case KEX_DH_GRP1_SHA1:
kex->dh = dh_new_group1();
break;
case KEX_DH_GRP14_SHA1:
case KEX_DH_GRP14_SHA256:
kex->dh = dh_new_group14();
break;
case KEX_DH_GRP16_SHA512:
kex->dh = dh_new_group16();
break;
case KEX_DH_GRP18_SHA512:
kex->dh = dh_new_group18();
break;
default:
r = SSH_ERR_INVALID_ARGUMENT;
goto out;
}
if (kex->dh == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
debug("sending SSH2_MSG_KEXDH_INIT");
if ((r = dh_gen_key(kex->dh, kex->we_need * 8)) != 0 ||
(r = sshpkt_start(ssh, SSH2_MSG_KEXDH_INIT)) != 0 ||
(r = sshpkt_put_bignum2(ssh, kex->dh->pub_key)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
#ifdef DEBUG_KEXDH
DHparams_print_fp(stderr, kex->dh);
fprintf(stderr, "pub= ");
BN_print_fp(stderr, kex->dh->pub_key);
fprintf(stderr, "\n");
#endif
debug("expecting SSH2_MSG_KEXDH_REPLY");
ssh_dispatch_set(ssh, SSH2_MSG_KEXDH_REPLY, &input_kex_dh);
r = 0;
out:
return r;
}
int
kexdh_server(struct ssh *ssh)
{
struct kex *kex = ssh->kex;
int r;
/* generate server DH public key */
switch (kex->kex_type) {
case KEX_DH_GRP1_SHA1:
kex->dh = dh_new_group1();
break;
case KEX_DH_GRP14_SHA1:
case KEX_DH_GRP14_SHA256:
kex->dh = dh_new_group14();
break;
case KEX_DH_GRP16_SHA512:
kex->dh = dh_new_group16();
break;
case KEX_DH_GRP18_SHA512:
kex->dh = dh_new_group18();
break;
default:
r = SSH_ERR_INVALID_ARGUMENT;
goto out;
}
if (kex->dh == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = dh_gen_key(kex->dh, kex->we_need * 8)) != 0)
goto out;
debug("expecting SSH2_MSG_KEXDH_INIT");
ssh_dispatch_set(ssh, SSH2_MSG_KEXDH_INIT, &input_kex_dh_init);
r = 0;
out:
if (r != 0) {
if (kex->dh) DH_free(kex->dh);
kex->dh = NULL;
}
return r;
}
