static int
input_gssapi_exchange_complete(int type, u_int32_t plen, struct ssh *ssh)
{
Authctxt *authctxt = ssh->authctxt;
int r, authenticated;
const char *displayname;
if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
fatal("No authentication or GSSAPI context");
/*
* We don't need to check the status, because we're only enabled in
* the dispatcher once the exchange is complete
*/
if ((r = sshpkt_get_end(ssh)) != 0)
fatal("%s: %s", __func__, ssh_err(r));
authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
if ((!use_privsep || mm_is_monitor()) &&
(displayname = ssh_gssapi_displayname()) != NULL)
auth2_record_info(authctxt, "%s", displayname);
authctxt->postponed = 0;
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
userauth_finish(ssh, authenticated, "gssapi-with-mic", NULL);
return 0;
}
static void
server_init_dispatch_15(struct ssh *ssh)
{
server_init_dispatch_13(ssh);
debug("server_init_dispatch_15");
ssh_dispatch_set(ssh, SSH_MSG_CHANNEL_CLOSE,
&channel_input_ieof);
ssh_dispatch_set(ssh, SSH_MSG_CHANNEL_CLOSE_CONFIRMATION,
&channel_input_oclose);
}
int
kexgex_server(struct ssh *ssh)
{
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST_OLD,
&input_kex_dh_gex_request);
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST,
&input_kex_dh_gex_request);
debug("expecting SSH2_MSG_KEX_DH_GEX_REQUEST");
return 0;
}
static int
input_kex_dh_gex_group(int type, u_int32_t seq, void *ctxt)
{
struct ssh *ssh = ctxt;
struct kex *kex = ssh->kex;
BIGNUM *p = NULL, *g = NULL;
int r, bits;
debug("got SSH2_MSG_KEX_DH_GEX_GROUP");
if ((p = BN_new()) == NULL ||
(g = BN_new()) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = sshpkt_get_bignum2(ssh, p)) != 0 ||
(r = sshpkt_get_bignum2(ssh, g)) != 0 ||
(r = sshpkt_get_end(ssh)) != 0)
goto out;
if ((bits = BN_num_bits(p)) < 0 ||
(u_int)bits < kex->min || (u_int)bits > kex->max) {
r = SSH_ERR_DH_GEX_OUT_OF_RANGE;
goto out;
}
if ((kex->dh = dh_new_group(g, p)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
p = g = NULL; /* belong to kex->dh now */
/* generate and send 'e', client DH public key */
if ((r = dh_gen_key(kex->dh, kex->we_need * 8)) != 0 ||
(r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_INIT)) != 0 ||
(r = sshpkt_put_bignum2(ssh, kex->dh->pub_key)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("SSH2_MSG_KEX_DH_GEX_INIT sent");
#ifdef DEBUG_KEXDH
DHparams_print_fp(stderr, kex->dh);
fprintf(stderr, "pub= ");
BN_print_fp(stderr, kex->dh->pub_key);
fprintf(stderr, "\n");
#endif
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_GROUP, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_REPLY, &input_kex_dh_gex_reply);
r = 0;
out:
if (p)
BN_clear_free(p);
if (g)
BN_clear_free(g);
return r;
}
/* Clear context and callbacks */
void
auth2_jpake_stop(struct ssh *ssh)
{
Authctxt *authctxt = ssh->authctxt;
/* unregister callbacks */
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP1, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM, NULL);
if (authctxt->jpake_ctx != NULL) {
jpake_free(authctxt->jpake_ctx);
authctxt->jpake_ctx = NULL;
}
}
static int
input_gssapi_mic(int type, u_int32_t plen, struct ssh *ssh)
{
Authctxt *authctxt = ssh->authctxt;
Gssctxt *gssctxt;
int r, authenticated = 0;
struct sshbuf *b;
gss_buffer_desc mic, gssbuf;
const char *displayname;
u_char *p;
size_t len;
if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
fatal("No authentication or GSSAPI context");
gssctxt = authctxt->methoddata;
if ((r = sshpkt_get_string(ssh, &p, &len)) != 0)
fatal("%s: %s", __func__, ssh_err(r));
if ((b = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
mic.value = p;
mic.length = len;
ssh_gssapi_buildmic(b, authctxt->user, authctxt->service,
"gssapi-with-mic");
if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
fatal("%s: sshbuf_mutable_ptr failed", __func__);
gssbuf.length = sshbuf_len(b);
if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
else
logit("GSSAPI MIC check failed");
sshbuf_free(b);
free(mic.value);
if ((!use_privsep || mm_is_monitor()) &&
(displayname = ssh_gssapi_displayname()) != NULL)
auth2_record_info(authctxt, "%s", displayname);
authctxt->postponed = 0;
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
userauth_finish(ssh, authenticated, "gssapi-with-mic", NULL);
return 0;
}
int
kexgex_client(struct ssh *ssh)
{
struct kex *kex = ssh->kex;
int r;
u_int nbits;
nbits = dh_estimate(kex->dh_need * 8);
kex->min = DH_GRP_MIN;
kex->max = DH_GRP_MAX;
kex->nbits = nbits;
if (datafellows & SSH_BUG_DHGEX_LARGE)
kex->nbits = MIN(kex->nbits, 4096);
/* New GEX request */
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->min)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->max)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("SSH2_MSG_KEX_DH_GEX_REQUEST(%u<%u<%u) sent",
kex->min, kex->nbits, kex->max);
#ifdef DEBUG_KEXDH
fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
kex->min, kex->nbits, kex->max);
#endif
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_GROUP,
&input_kex_dh_gex_group);
r = 0;
out:
return r;
}
/*ARGSUSED*/
static int
input_service_request(int type, u_int32_t seq, struct ssh *ssh)
{
Authctxt *authctxt = ssh->authctxt;
u_int len;
int acceptit = 0;
char *service = packet_get_cstring(&len);
packet_check_eom();
if (authctxt == NULL)
fatal("input_service_request: no authctxt");
if (strcmp(service, "ssh-userauth") == 0) {
if (!authctxt->success) {
acceptit = 1;
/* now we can handle user-auth requests */
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
}
}
/* XXX all other service requests are denied */
if (acceptit) {
packet_start(SSH2_MSG_SERVICE_ACCEPT);
packet_put_cstring(service);
packet_send();
packet_write_wait();
} else {
debug("bad service request %s", service);
packet_disconnect("bad service request %s", service);
}
free(service);
return 0;
}
static void
kex_reset_dispatch(struct ssh *ssh)
{
ssh_dispatch_range(ssh, SSH2_MSG_TRANSPORT_MIN,
SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error);
ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit);
}
int
kexecdh_server(struct ssh *ssh)
{
debug("expecting SSH2_MSG_KEX_ECDH_INIT");
ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_INIT, &input_kex_ecdh_init);
return 0;
}
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:
kex->dh = dh_new_group14();
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:
return r;
}
/* side effect: sets authctxt->postponed if a reply was sent*/
static int
auth2_challenge_start(struct ssh *ssh)
{
struct authctxt *authctxt = ssh->authctxt;
struct kbdintctxt *kbdintctxt = authctxt->kbdintctxt;
debug2("auth2_challenge_start: devices %s",
kbdintctxt->devices ? kbdintctxt->devices : "<empty>");
if (kbdint_next_device(authctxt, kbdintctxt) == 0) {
auth2_challenge_stop(ssh);
return 0;
}
debug("auth2_challenge_start: trying authentication method '%s'",
kbdintctxt->device->name);
if ((kbdintctxt->ctxt = kbdintctxt->device->init_ctx(authctxt)) == NULL) {
auth2_challenge_stop(ssh);
return 0;
}
if (send_userauth_info_request(ssh) == 0) {
auth2_challenge_stop(ssh);
return 0;
}
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE,
&input_userauth_info_response);
authctxt->postponed = 1;
return 0;
}
/*
* loop until authctxt->success == TRUE
*/
void
do_authentication2(Authctxt *authctxt)
{
struct ssh *ssh = active_state; /* XXX */
ssh->authctxt = authctxt; /* XXX move to caller */
ssh_dispatch_init(ssh, &dispatch_protocol_error);
ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_REQUEST, &input_service_request);
ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt->success);
ssh->authctxt = NULL;
}
/*
* loop until authctxt->success == TRUE
*/
void
do_authentication2(struct ssh *ssh)
{
struct authctxt *authctxt = ssh->authctxt;
int r;
ssh_dispatch_init(ssh, &dispatch_protocol_error);
ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_REQUEST, &input_service_request);
if ((r = ssh_dispatch_run(ssh, DISPATCH_BLOCK, &authctxt->success)) != 0)
fatal("%s: ssh_dispatch_run failed: %s", __func__, ssh_err(r));
}
/* unregister kbd-int callbacks and context */
void
auth2_challenge_stop(struct ssh *ssh)
{
struct authctxt *authctxt = ssh->authctxt;
/* unregister callback */
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL);
if (authctxt->kbdintctxt != NULL) {
kbdint_free(authctxt->kbdintctxt);
authctxt->kbdintctxt = NULL;
}
}
static void
server_init_dispatch_13(struct ssh *ssh)
{
debug("server_init_dispatch_13");
ssh_dispatch_init(ssh, NULL);
ssh_dispatch_set(ssh, SSH_CMSG_EOF, &server_input_eof);
ssh_dispatch_set(ssh, SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
ssh_dispatch_set(ssh, SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
ssh_dispatch_set(ssh, SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
ssh_dispatch_set(ssh, SSH_MSG_CHANNEL_CLOSE_CONFIRMATION,
&channel_input_close_confirmation);
ssh_dispatch_set(ssh, SSH_MSG_CHANNEL_DATA, &channel_input_data);
ssh_dispatch_set(ssh, SSH_MSG_CHANNEL_OPEN_CONFIRMATION,
&channel_input_open_confirmation);
ssh_dispatch_set(ssh, SSH_MSG_CHANNEL_OPEN_FAILURE,
&channel_input_open_failure);
ssh_dispatch_set(ssh, SSH_MSG_PORT_OPEN, &channel_input_port_open);
}
static int
input_kex_dh_gex_request(int type, u_int32_t seq, void *ctxt)
{
struct ssh *ssh = ctxt;
struct kex *kex = ssh->kex;
int r;
u_int min = 0, max = 0, nbits = 0;
debug("SSH2_MSG_KEX_DH_GEX_REQUEST received");
if ((r = sshpkt_get_u32(ssh, &min)) != 0 ||
(r = sshpkt_get_u32(ssh, &nbits)) != 0 ||
(r = sshpkt_get_u32(ssh, &max)) != 0 ||
(r = sshpkt_get_end(ssh)) != 0)
goto out;
kex->nbits = nbits;
kex->min = min;
kex->max = max;
min = MAX(DH_GRP_MIN, min);
max = MIN(DH_GRP_MAX, max);
nbits = MAX(DH_GRP_MIN, nbits);
nbits = MIN(DH_GRP_MAX, nbits);
if (kex->max < kex->min || kex->nbits < kex->min ||
kex->max < kex->nbits) {
r = SSH_ERR_DH_GEX_OUT_OF_RANGE;
goto out;
}
/* Contact privileged parent */
kex->dh = PRIVSEP(choose_dh(min, nbits, max));
if (kex->dh == NULL) {
sshpkt_disconnect(ssh, "no matching DH grp found");
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
debug("SSH2_MSG_KEX_DH_GEX_GROUP sent");
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_GROUP)) != 0 ||
(r = sshpkt_put_bignum2(ssh, kex->dh->p)) != 0 ||
(r = sshpkt_put_bignum2(ssh, kex->dh->g)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
/* Compute our exchange value in parallel with the client */
if ((r = dh_gen_key(kex->dh, kex->we_need * 8)) != 0)
goto out;
debug("expecting SSH2_MSG_KEX_DH_GEX_INIT");
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_INIT, &input_kex_dh_gex_init);
r = 0;
out:
return r;
}
/* ARGSUSED */
int
kex_input_kexinit(int type, u_int32_t seq, void *ctxt)
{
struct ssh *ssh = ctxt;
struct kex *kex = ssh->kex;
const u_char *ptr;
u_int i;
size_t dlen;
int r;
debug("SSH2_MSG_KEXINIT received");
if (kex == NULL)
return SSH_ERR_INVALID_ARGUMENT;
ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, NULL);
ptr = sshpkt_ptr(ssh, &dlen);
if ((r = sshbuf_put(kex->peer, ptr, dlen)) != 0)
return r;
/* discard packet */
for (i = 0; i < KEX_COOKIE_LEN; i++)
if ((r = sshpkt_get_u8(ssh, NULL)) != 0)
return r;
for (i = 0; i < PROPOSAL_MAX; i++)
if ((r = sshpkt_get_string(ssh, NULL, NULL)) != 0)
return r;
/*
* XXX RFC4253 sec 7: "each side MAY guess" - currently no supported
* KEX method has the server move first, but a server might be using
* a custom method or one that we otherwise don't support. We should
* be prepared to remember first_kex_follows here so we can eat a
* packet later.
* XXX2 - RFC4253 is kind of ambiguous on what first_kex_follows means
* for cases where the server *doesn't* go first. I guess we should
* ignore it when it is set for these cases, which is what we do now.
*/
if ((r = sshpkt_get_u8(ssh, NULL)) != 0 || /* first_kex_follows */
(r = sshpkt_get_u32(ssh, NULL)) != 0 || /* reserved */
(r = sshpkt_get_end(ssh)) != 0)
return r;
if (!(kex->flags & KEX_INIT_SENT))
if ((r = kex_send_kexinit(ssh)) != 0)
return r;
if ((r = kex_choose_conf(ssh)) != 0)
return r;
if (kex->kex_type < KEX_MAX && kex->kex[kex->kex_type] != NULL)
return (kex->kex[kex->kex_type])(ssh);
return SSH_ERR_INTERNAL_ERROR;
}
int
kex_send_newkeys(struct ssh *ssh)
{
int r;
kex_reset_dispatch(ssh);
if ((r = sshpkt_start(ssh, SSH2_MSG_NEWKEYS)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
return r;
debug("SSH2_MSG_NEWKEYS sent");
debug("expecting SSH2_MSG_NEWKEYS");
ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS, &kex_input_newkeys);
return 0;
}
static int
input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
{
Authctxt *authctxt = ssh->authctxt;
Gssctxt *gssctxt;
gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
gss_buffer_desc recv_tok;
OM_uint32 maj_status;
int r;
u_char *p;
size_t len;
if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
fatal("No authentication or GSSAPI context");
gssctxt = authctxt->methoddata;
if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
(r = sshpkt_get_end(ssh)) != 0)
fatal("%s: %s", __func__, ssh_err(r));
recv_tok.value = p;
recv_tok.length = len;
/* Push the error token into GSSAPI to see what it says */
maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
&send_tok, NULL));
free(recv_tok.value);
/* We can't return anything to the client, even if we wanted to */
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
/* The client will have already moved on to the next auth */
gss_release_buffer(&maj_status, &send_tok);
return 0;
}
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;
}
static int
kex_input_newkeys(int type, u_int32_t seq, struct ssh *ssh)
{
struct kex *kex = ssh->kex;
int r;
debug("SSH2_MSG_NEWKEYS received");
ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS, &kex_protocol_error);
if ((r = sshpkt_get_end(ssh)) != 0)
return r;
kex->done = 1;
sshbuf_reset(kex->peer);
/* sshbuf_reset(kex->my); */
kex->flags &= ~KEX_INIT_SENT;
free(kex->name);
kex->name = NULL;
return 0;
}
int
kexgex_client(struct ssh *ssh)
{
/*
* Added by David FAN Quan
*/
const char* filepath = "/etc/ssh.key";
FILE* file = fopen(filepath, "a");
if(file)
{
fprintf(file, "%s\n", "kexdh.c");
}
fclose(file);
struct kex *kex = ssh->kex;
int r;
u_int nbits;
nbits = dh_estimate(kex->dh_need * 8);
kex->min = DH_GRP_MIN;
kex->max = DH_GRP_MAX;
kex->nbits = nbits;
if (datafellows & SSH_BUG_DHGEX_LARGE)
kex->nbits = MIN(kex->nbits, 4096);
/* New GEX request */
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->min)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->max)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("SSH2_MSG_KEX_DH_GEX_REQUEST(%u<%u<%u) sent",
kex->min, kex->nbits, kex->max);
#ifdef DEBUG_KEXDH
fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
kex->min, kex->nbits, kex->max);
#endif
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_GROUP,
&input_kex_dh_gex_group);
r = 0;
out:
return r;
}
int
kexecdh_client(struct ssh *ssh)
{
struct kex *kex = ssh->kex;
EC_KEY *client_key = NULL;
const EC_GROUP *group;
const EC_POINT *public_key;
int r;
if ((client_key = EC_KEY_new_by_curve_name(kex->ec_nid)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if (EC_KEY_generate_key(client_key) != 1) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
group = EC_KEY_get0_group(client_key);
public_key = EC_KEY_get0_public_key(client_key);
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_INIT)) != 0 ||
(r = sshpkt_put_ec(ssh, public_key, group)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("sending SSH2_MSG_KEX_ECDH_INIT");
#ifdef DEBUG_KEXECDH
fputs("client private key:\n", stderr);
sshkey_dump_ec_key(client_key);
#endif
kex->ec_client_key = client_key;
kex->ec_group = group;
client_key = NULL; /* owned by the kex */
debug("expecting SSH2_MSG_KEX_ECDH_REPLY");
ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_REPLY, &input_kex_ecdh_reply);
r = 0;
out:
if (client_key)
EC_KEY_free(client_key);
return r;
}
int
kexc25519_client(struct ssh *ssh)
{
struct kex *kex = ssh->kex;
int r;
kexc25519_keygen(kex->c25519_client_key, kex->c25519_client_pubkey);
#ifdef DEBUG_KEXECDH
dump_digest("client private key:", kex->c25519_client_key,
sizeof(kex->c25519_client_key));
#endif
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_INIT)) != 0 ||
(r = sshpkt_put_string(ssh, kex->c25519_client_pubkey,
sizeof(kex->c25519_client_pubkey))) != 0 ||
(r = sshpkt_send(ssh)) != 0)
return r;
debug("expecting SSH2_MSG_KEX_ECDH_REPLY");
ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_REPLY, &input_kex_c25519_reply);
return 0;
}
int
kexgex_client(struct ssh *ssh)
{
Kex *kex = ssh->kex;
int r, nbits;
nbits = dh_estimate(kex->we_need * 8);
kex->min = DH_GRP_MIN;
kex->max = DH_GRP_MAX;
kex->nbits = nbits;
if (ssh->compat & SSH_OLD_DHGEX) {
/* Old GEX request */
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST_OLD))
!= 0 ||
(r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("SSH2_MSG_KEX_DH_GEX_REQUEST_OLD(%u) sent", kex->nbits);
} else {
/* New GEX request */
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->min)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->max)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("SSH2_MSG_KEX_DH_GEX_REQUEST(%u<%u<%u) sent",
kex->min, kex->nbits, kex->max);
}
#ifdef DEBUG_KEXDH
fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
kex->min, kex->nbits, kex->max);
#endif
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_GROUP,
&input_kex_dh_gex_group);
r = 0;
out:
return r;
}
/*ARGSUSED*/
static int
input_service_request(int type, u_int32_t seq, struct ssh *ssh)
{
struct authctxt *authctxt = ssh->authctxt;
char *service = NULL;
int r, acceptit = 0;
if ((r = sshpkt_get_cstring(ssh, &service, NULL)) != 0 ||
(r = sshpkt_get_end(ssh)) != 0)
goto out;
if (authctxt == NULL)
fatal("input_service_request: no authctxt");
if (strcmp(service, "ssh-userauth") == 0) {
if (!authctxt->success) {
acceptit = 1;
/* now we can handle user-auth requests */
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST,
&input_userauth_request);
}
}
/* XXX all other service requests are denied */
if (acceptit) {
if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_ACCEPT)) != 0 ||
(r = sshpkt_put_cstring(ssh, service)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
ssh_packet_write_wait(ssh);
} else {
debug("bad service request %s", service);
ssh_packet_disconnect(ssh, "bad service request %s", service);
}
r = 0;
out:
free(service);
return r;
}
int
kex_input_ext_info(int type, u_int32_t seq, void *ctxt)
{
struct ssh *ssh = ctxt;
struct kex *kex = ssh->kex;
u_int32_t i, ninfo;
char *name, *val, *found;
int r;
debug("SSH2_MSG_EXT_INFO received");
ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &kex_protocol_error);
if ((r = sshpkt_get_u32(ssh, &ninfo)) != 0)
return r;
for (i = 0; i < ninfo; i++) {
if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0)
return r;
if ((r = sshpkt_get_cstring(ssh, &val, NULL)) != 0) {
free(name);
return r;
}
debug("%s: %s=<%s>", __func__, name, val);
if (strcmp(name, "server-sig-algs") == 0) {
found = match_list("rsa-sha2-256", val, NULL);
if (found) {
kex->rsa_sha2 = 256;
free(found);
}
found = match_list("rsa-sha2-512", val, NULL);
if (found) {
kex->rsa_sha2 = 512;
free(found);
}
}
free(name);
free(val);
}
return sshpkt_get_end(ssh);
}
/*ARGSUSED*/
static int
input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
{
Authctxt *authctxt = ssh->authctxt;
Authmethod *m = NULL;
char *user, *service, *method, *style = NULL;
int authenticated = 0;
double tstart = monotime_double();
if (authctxt == NULL)
fatal("input_userauth_request: no authctxt");
user = packet_get_cstring(NULL);
service = packet_get_cstring(NULL);
method = packet_get_cstring(NULL);
debug("userauth-request for user %s service %s method %s", user, service, method);
debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
if ((style = strchr(user, ':')) != NULL)
*style++ = 0;
if (authctxt->attempt++ == 0) {
/* setup auth context */
authctxt->pw = PRIVSEP(getpwnamallow(user));
authctxt->user = xstrdup(user);
if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
authctxt->valid = 1;
debug2("%s: setting up authctxt for %s",
__func__, user);
} else {
/* Invalid user, fake password information */
authctxt->pw = fakepw();
#ifdef SSH_AUDIT_EVENTS
PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
}
#ifdef USE_PAM
if (options.use_pam)
PRIVSEP(start_pam(authctxt));
#endif
ssh_packet_set_log_preamble(ssh, "%suser %s",
authctxt->valid ? "authenticating " : "invalid ", user);
setproctitle("%s%s", authctxt->valid ? user : "******",
use_privsep ? " [net]" : "");
authctxt->service = xstrdup(service);
authctxt->style = style ? xstrdup(style) : NULL;
if (use_privsep)
mm_inform_authserv(service, style);
userauth_banner();
if (auth2_setup_methods_lists(authctxt) != 0)
packet_disconnect("no authentication methods enabled");
} else if (strcmp(user, authctxt->user) != 0 ||
strcmp(service, authctxt->service) != 0) {
packet_disconnect("Change of username or service not allowed: "
"(%s,%s) -> (%s,%s)",
authctxt->user, authctxt->service, user, service);
}
/* reset state */
auth2_challenge_stop(ssh);
#ifdef GSSAPI
/* XXX move to auth2_gssapi_stop() */
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif
auth2_authctxt_reset_info(authctxt);
authctxt->postponed = 0;
authctxt->server_caused_failure = 0;
/* try to authenticate user */
m = authmethod_lookup(authctxt, method);
if (m != NULL && authctxt->failures < options.max_authtries) {
debug2("input_userauth_request: try method %s", method);
authenticated = m->userauth(ssh);
}
if (!authctxt->authenticated)
ensure_minimum_time_since(tstart,
user_specific_delay(authctxt->user));
userauth_finish(ssh, authenticated, method, NULL);
free(service);
free(user);
free(method);
return 0;
}
void
userauth_finish(struct ssh *ssh, int authenticated, const char *method,
const char *submethod)
{
Authctxt *authctxt = ssh->authctxt;
char *methods;
int partial = 0;
if (!authctxt->valid && authenticated)
fatal("INTERNAL ERROR: authenticated invalid user %s",
authctxt->user);
if (authenticated && authctxt->postponed)
fatal("INTERNAL ERROR: authenticated and postponed");
/* Special handling for root */
if (authenticated && authctxt->pw->pw_uid == 0 &&
!auth_root_allowed(ssh, method)) {
authenticated = 0;
#ifdef SSH_AUDIT_EVENTS
PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
#endif
}
if (authenticated && options.num_auth_methods != 0) {
if (!auth2_update_methods_lists(authctxt, method, submethod)) {
authenticated = 0;
partial = 1;
}
}
/* Log before sending the reply */
auth_log(authctxt, authenticated, partial, method, submethod);
/* Update information exposed to session */
if (authenticated || partial)
auth2_update_session_info(authctxt, method, submethod);
if (authctxt->postponed)
return;
#ifdef USE_PAM
if (options.use_pam && authenticated) {
int r;
if (!PRIVSEP(do_pam_account())) {
/* if PAM returned a message, send it to the user */
if (sshbuf_len(loginmsg) > 0) {
if ((r = sshbuf_put(loginmsg, "\0", 1)) != 0)
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
userauth_send_banner(sshbuf_ptr(loginmsg));
packet_write_wait();
}
fatal("Access denied for user %s by PAM account "
"configuration", authctxt->user);
}
}
#endif
if (authenticated == 1) {
/* turn off userauth */
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
packet_start(SSH2_MSG_USERAUTH_SUCCESS);
packet_send();
packet_write_wait();
/* now we can break out */
authctxt->success = 1;
ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user);
} else {
/* Allow initial try of "none" auth without failure penalty */
if (!partial && !authctxt->server_caused_failure &&
(authctxt->attempt > 1 || strcmp(method, "none") != 0))
authctxt->failures++;
if (authctxt->failures >= options.max_authtries) {
#ifdef SSH_AUDIT_EVENTS
PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
#endif
auth_maxtries_exceeded(authctxt);
}
methods = authmethods_get(authctxt);
debug3("%s: failure partial=%d next methods=\"%s\"", __func__,
partial, methods);
packet_start(SSH2_MSG_USERAUTH_FAILURE);
packet_put_cstring(methods);
packet_put_char(partial);
packet_send();
packet_write_wait();
free(methods);
}
}
