/* {{{ libssh2_kex_method_diffie_hellman_group_exchange_sha1_key_exchange
* Diffie-Hellman Group Exchange Key Exchange using SHA1
* Negotiates random(ish) group for secret derivation
*/
static int libssh2_kex_method_diffie_hellman_group_exchange_sha1_key_exchange(LIBSSH2_SESSION *session)
{
unsigned char request[13], *s, *data;
unsigned long data_len, p_len, g_len, request_len;
_libssh2_bn *p = _libssh2_bn_init ();
_libssh2_bn *g = _libssh2_bn_init ();
int ret;
/* Ask for a P and G pair */
#ifdef LIBSSH2_DH_GEX_NEW
request[0] = SSH_MSG_KEX_DH_GEX_REQUEST;
libssh2_htonu32(request + 1, LIBSSH2_DH_GEX_MINGROUP);
libssh2_htonu32(request + 5, LIBSSH2_DH_GEX_OPTGROUP);
libssh2_htonu32(request + 9, LIBSSH2_DH_GEX_MAXGROUP);
request_len = 13;
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Initiating Diffie-Hellman Group-Exchange (New Method)");
#endif
#else
request[0] = SSH_MSG_KEX_DH_GEX_REQUEST_OLD;
libssh2_htonu32(request + 1, LIBSSH2_DH_GEX_OPTGROUP);
request_len = 5;
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Initiating Diffie-Hellman Group-Exchange (Old Method)");
#endif
#endif
if (libssh2_packet_write(session, request, request_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send Group Exchange Request", 0);
ret = -1;
goto dh_gex_clean_exit;
}
if (libssh2_packet_require(session, SSH_MSG_KEX_DH_GEX_GROUP, &data, &data_len)) {
libssh2_error(session, LIBSSH2_ERROR_TIMEOUT, "Timeout waiting for GEX_GROUP reply", 0);
ret = -1;
goto dh_gex_clean_exit;
}
s = data + 1;
p_len = libssh2_ntohu32(s); s += 4;
_libssh2_bn_from_bin(p, p_len, s); s += p_len;
g_len = libssh2_ntohu32(s); s += 4;
_libssh2_bn_from_bin(g, g_len, s); s += g_len;
ret = libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(session, g, p, p_len, SSH_MSG_KEX_DH_GEX_INIT, SSH_MSG_KEX_DH_GEX_REPLY, data + 1, data_len - 1);
LIBSSH2_FREE(session, data);
dh_gex_clean_exit:
_libssh2_bn_free(g);
_libssh2_bn_free(p);
return ret;
}
/* {{{ proto libssh2_userauth_list
* List authentication methods
* Will yield successful login if "none" happens to be allowable for this user
* Not a common configuration for any SSH server though
* username should be NULL, or a null terminated string
*/
LIBSSH2_API char *libssh2_userauth_list(LIBSSH2_SESSION *session, const char *username, unsigned int username_len)
{
unsigned char reply_codes[3] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, 0 };
unsigned long data_len = username_len + 31; /* packet_type(1) + username_len(4) + service_len(4) + service(14)"ssh-connection" +
method_len(4) + method(4)"none" */
unsigned long methods_len;
unsigned char *data, *s;
s = data = LIBSSH2_ALLOC(session, data_len);
if (!data) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for userauth_list", 0);
return NULL;
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
libssh2_htonu32(s, username_len); s += 4;
if (username) {
memcpy(s, username, username_len); s += username_len;
}
libssh2_htonu32(s, 14); s += 4;
memcpy(s, "ssh-connection", 14); s += 14;
libssh2_htonu32(s, 4); s += 4;
memcpy(s, "none", 4); s += 4;
if (libssh2_packet_write(session, data, data_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-none request", 0);
LIBSSH2_FREE(session, data);
return NULL;
}
LIBSSH2_FREE(session, data);
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
return NULL;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
/* Wow, who'dve thought... */
LIBSSH2_FREE(session, data);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return NULL;
}
methods_len = libssh2_ntohu32(data + 1);
memcpy(data, data + 5, methods_len);
data[methods_len] = '\0';
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Permitted auth methods: %s", data);
#endif
return (char *)data;
}
/* {{{ libssh2_mac_method_hmac_ripemd160_hash
* Calculate hash using ripemd160 value
*/
static int
libssh2_mac_method_hmac_ripemd160_hash(LIBSSH2_SESSION * session,
unsigned char *buf, unsigned long seqno,
const unsigned char *packet,
unsigned long packet_len,
const unsigned char *addtl,
unsigned long addtl_len,
void **abstract)
{
libssh2_hmac_ctx ctx;
unsigned char seqno_buf[4];
(void) session;
libssh2_htonu32(seqno_buf, seqno);
libssh2_hmac_ripemd160_init(&ctx, *abstract, 20);
libssh2_hmac_update(ctx, seqno_buf, 4);
libssh2_hmac_update(ctx, packet, packet_len);
if (addtl && addtl_len) {
libssh2_hmac_update(ctx, addtl, addtl_len);
}
libssh2_hmac_final(ctx, buf);
libssh2_hmac_cleanup(&ctx);
return 0;
}
/* {{{ libssh2_publickey_remove_ex
* Remove an existing publickey so that authentication can no longer be performed using it
*/
LIBSSH2_API int libssh2_publickey_remove_ex(LIBSSH2_PUBLICKEY *pkey, const unsigned char *name, unsigned long name_len,
const unsigned char *blob, unsigned long blob_len)
{
LIBSSH2_CHANNEL *channel = pkey->channel;
LIBSSH2_SESSION *session = channel->session;
unsigned char *s, *packet = NULL;
unsigned long packet_len = 22 + name_len + blob_len;
/* packet_len(4) +
remove_len(4) +
"remove"(6) +
name_len(4) +
{name}
blob_len(4) +
{blob} */
packet = LIBSSH2_ALLOC(session, packet_len);
if (!packet) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for publickey \"remove\" packet", 0);
return -1;
}
s = packet;
libssh2_htonu32(s, packet_len - 4); s += 4;
libssh2_htonu32(s, sizeof("remove") - 1); s += 4;
memcpy(s, "remove", sizeof("remove") - 1); s += sizeof("remove") - 1;
libssh2_htonu32(s, name_len); s += 4;
memcpy(s, name, name_len); s += name_len;
libssh2_htonu32(s, blob_len); s += 4;
memcpy(s, blob, blob_len); s += blob_len;
#ifdef LIBSSH2_DEBUG_PUBLICKEY
_libssh2_debug(session, LIBSSH2_DBG_PUBLICKEY, "Sending publickey \"remove\" packet: type=%s blob_len=%ld", name, blob_len);
#endif
if ((s - packet) != libssh2_channel_write(channel, packet, (s - packet))) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send publickey remove packet", 0);
LIBSSH2_FREE(session, packet);
return -1;
}
LIBSSH2_FREE(session, packet);
packet = NULL;
return libssh2_publickey_response_success(pkey);
}
/* {{{ libssh2_kex_method_list
* Generate formatted preference list in buf
*/
static size_t libssh2_kex_method_list(unsigned char *buf, size_t list_strlen, LIBSSH2_COMMON_METHOD **method)
{
libssh2_htonu32(buf, list_strlen);
buf += 4;
if (!method || !*method) {
return 4;
}
while (*method && (*method)->name) {
int mlen = strlen((*method)->name);
memcpy(buf, (*method)->name, mlen);
buf += mlen;
*(buf++) = ',';
method++;
}
return list_strlen + 4;
}
/* {{{ libssh2_mac_method_hmac_sha1_hash
* Calculate hash using full sha1 value
*/
static int libssh2_mac_method_hmac_sha1_hash(LIBSSH2_SESSION *session, unsigned char *buf, unsigned long seqno,
const unsigned char *packet, unsigned long packet_len,
const unsigned char *addtl, unsigned long addtl_len, void **abstract)
{
HMAC_CTX ctx;
unsigned char seqno_buf[4];
libssh2_htonu32(seqno_buf, seqno);
HMAC_Init(&ctx, *abstract, 20, EVP_sha1());
HMAC_Update(&ctx, seqno_buf, 4);
HMAC_Update(&ctx, packet, packet_len);
if (addtl && addtl_len) {
HMAC_Update(&ctx, addtl, addtl_len);
}
HMAC_Final(&ctx, buf, NULL);
HMAC_cleanup(&ctx);
return 0;
}
/* {{{ libssh2_userauth_publickey_fromfile_ex
* Authenticate using a keypair found in the named files
*/
LIBSSH2_API int libssh2_userauth_publickey_fromfile_ex(LIBSSH2_SESSION *session, const char *username, unsigned int username_len,
const char *publickey, const char *privatekey,
const char *passphrase)
{
LIBSSH2_HOSTKEY_METHOD *privkeyobj;
void *abstract;
unsigned char buf[5];
struct iovec datavec[4];
unsigned char *method, *pubkeydata, *packet, *s, *b, *sig, *data;
unsigned char reply_codes[4] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, SSH_MSG_USERAUTH_PK_OK, 0 };
unsigned long method_len, pubkeydata_len, packet_len, sig_len, data_len;
if (libssh2_file_read_publickey(session, &method, &method_len, &pubkeydata, &pubkeydata_len, publickey)) {
return -1;
}
packet_len = username_len + method_len + pubkeydata_len + 45; /* packet_type(1) + username_len(4) + servicename_len(4) +
service_name(14)"ssh-connection" + authmethod_len(4) +
authmethod(9)"publickey" + sig_included(1)'\0' +
algmethod_len(4) + publickey_len(4) */
/* Preallocate space for an overall length, method name again,
* and the signature, which won't be any larger than the size of the publickeydata itself */
s = packet = LIBSSH2_ALLOC(session, packet_len + 4 + (4 + method_len) + (4 + pubkeydata_len));
*(s++) = SSH_MSG_USERAUTH_REQUEST;
libssh2_htonu32(s, username_len); s += 4;
memcpy(s, username, username_len); s += username_len;
libssh2_htonu32(s, 14); s += 4;
memcpy(s, "ssh-connection", 14); s += 14;
libssh2_htonu32(s, 9); s += 4;
memcpy(s, "publickey", 9); s += 9;
b = s;
*(s++) = 0; /* Not sending signature with *this* packet */
libssh2_htonu32(s, method_len); s += 4;
memcpy(s, method, method_len); s += method_len;
libssh2_htonu32(s, pubkeydata_len); s += 4;
memcpy(s, pubkeydata, pubkeydata_len); s += pubkeydata_len;
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Attempting publickey authentication");
#endif
if (libssh2_packet_write(session, packet, packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-publickey request", 0);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, pubkeydata);
return -1;
}
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, pubkeydata);
return -1;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Pubkey authentication prematurely successful");
#endif
/* God help any SSH server that allows an UNVERIFIED public key to validate the user */
LIBSSH2_FREE(session, data);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, pubkeydata);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return 0;
}
if (data[0] == SSH_MSG_USERAUTH_FAILURE) {
/* This public key is not allowed for this user on this server */
LIBSSH2_FREE(session, data);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, pubkeydata);
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNRECOGNIZED, "Username/PublicKey combination invalid", 0);
return -1;
}
/* Semi-Success! */
LIBSSH2_FREE(session, data);
LIBSSH2_FREE(session, pubkeydata);
if (libssh2_file_read_privatekey(session, &privkeyobj, &abstract, (const char *)method, method_len, privatekey, passphrase)) {
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, packet);
return -1;
}
*b = 0xFF;
libssh2_htonu32(buf, session->session_id_len);
datavec[0].iov_base = buf;
datavec[0].iov_len = 4;
datavec[1].iov_base = session->session_id;
datavec[1].iov_len = session->session_id_len;
datavec[2].iov_base = packet;
datavec[2].iov_len = packet_len;
if (privkeyobj->signv(session, &sig, &sig_len, 3, datavec, &abstract)) {
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, packet);
if (privkeyobj->dtor) {
privkeyobj->dtor(session, &abstract);
}
return -1;
}
if (privkeyobj->dtor) {
privkeyobj->dtor(session, &abstract);
}
if (sig_len > pubkeydata_len) {
/* Should *NEVER* happen, but...well.. better safe than sorry */
packet = LIBSSH2_REALLOC(session, packet, packet_len + 4 + (4 + method_len) + (4 + sig_len)); /* PK sigblob */
if (!packet) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Failed allocating additional space for userauth-publickey packet", 0);
LIBSSH2_FREE(session, method);
return -1;
}
}
s = packet + packet_len;
libssh2_htonu32(s, 4 + method_len + 4 + sig_len); s += 4;
libssh2_htonu32(s, method_len); s += 4;
memcpy(s, method, method_len); s += method_len;
LIBSSH2_FREE(session, method);
libssh2_htonu32(s, sig_len); s += 4;
memcpy(s, sig, sig_len); s += sig_len;
LIBSSH2_FREE(session, sig);
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Attempting publickey authentication -- phase 2");
#endif
if (libssh2_packet_write(session, packet, s - packet)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-publickey request", 0);
LIBSSH2_FREE(session, packet);
return -1;
}
LIBSSH2_FREE(session, packet);
/* PK_OK is no longer valid */
reply_codes[2] = 0;
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
return -1;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Publickey authentication successful");
#endif
/* We are us and we've proved it. */
LIBSSH2_FREE(session, data);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return 0;
}
/* This public key is not allowed for this user on this server */
LIBSSH2_FREE(session, data);
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED, "Invalid signature for supplied public key, or bad username/public key combination", 0);
return -1;
}
/* {{{ libssh2_userauth_password
* Plain ol' login
*/
LIBSSH2_API int libssh2_userauth_password_ex(LIBSSH2_SESSION *session, const char *username, unsigned int username_len,
const char *password, unsigned int password_len,
LIBSSH2_PASSWD_CHANGEREQ_FUNC((*passwd_change_cb)))
{
unsigned char *data, *s, reply_codes[4] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, SSH_MSG_USERAUTH_PASSWD_CHANGEREQ, 0 };
unsigned long data_len = username_len + password_len + 40; /* packet_type(1) + username_len(4) + service_len(4) + service(14)"ssh-connection" +
method_len(4) + method(8)"password" + chgpwdbool(1) + password_len(4) */
s = data = LIBSSH2_ALLOC(session, data_len);
if (!data) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for userauth-password request", 0);
return -1;
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
libssh2_htonu32(s, username_len); s += 4;
memcpy(s, username, username_len); s += username_len;
libssh2_htonu32(s, sizeof("ssh-connection") - 1); s += 4;
memcpy(s, "ssh-connection", sizeof("ssh-connection") - 1); s += sizeof("ssh-connection") - 1;
libssh2_htonu32(s, sizeof("password") - 1); s += 4;
memcpy(s, "password", sizeof("password") - 1); s += sizeof("password") - 1;
*s = '\0'; s++;
libssh2_htonu32(s, password_len); s += 4;
memcpy(s, password, password_len); s += password_len;
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Attempting to login using password authentication");
#endif
if (libssh2_packet_write(session, data, data_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-password request", 0);
LIBSSH2_FREE(session, data);
return -1;
}
LIBSSH2_FREE(session, data);
password_response:
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
return -1;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Password authentication successful");
#endif
LIBSSH2_FREE(session, data);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return 0;
}
if (data[0] == SSH_MSG_USERAUTH_PASSWD_CHANGEREQ) {
char *newpw = NULL;
int newpw_len = 0;
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Password change required");
#endif
LIBSSH2_FREE(session, data);
if (passwd_change_cb) {
passwd_change_cb(session, &newpw, &newpw_len, &session->abstract);
if (!newpw) {
libssh2_error(session, LIBSSH2_ERROR_PASSWORD_EXPIRED, "Password expired, and callback failed", 0);
return -1;
}
data_len = username_len + password_len + 44 + newpw_len; /* basic data_len + newpw_len(4) */
s = data = LIBSSH2_ALLOC(session, data_len);
if (!data) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for userauth-password-change request", 0);
return -1;
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
libssh2_htonu32(s, username_len); s += 4;
memcpy(s, username, username_len); s += username_len;
libssh2_htonu32(s, sizeof("ssh-connection") - 1); s += 4;
memcpy(s, "ssh-connection", sizeof("ssh-connection") - 1); s += sizeof("ssh-connection") - 1;
libssh2_htonu32(s, sizeof("password") - 1); s += 4;
memcpy(s, "password", sizeof("password") - 1); s += sizeof("password") - 1;
*s = 0xFF; s++;
libssh2_htonu32(s, password_len); s += 4;
memcpy(s, password, password_len); s += password_len;
libssh2_htonu32(s, newpw_len); s += 4;
memcpy(s, newpw, newpw_len); s += newpw_len;
if (libssh2_packet_write(session, data, data_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-password-change request", 0);
LIBSSH2_FREE(session, data);
return -1;
}
LIBSSH2_FREE(session, data);
LIBSSH2_FREE(session, newpw);
/* Ugliest use of goto ever. Blame it on the askN => requirev migration. */
goto password_response;
} else {
libssh2_error(session, LIBSSH2_ERROR_PASSWORD_EXPIRED, "Password Expired, and no callback specified", 0);
return -1;
}
}
/* FAILURE */
LIBSSH2_FREE(session, data);
return -1;
}
/* {{{ libssh2_packet_write
* Send a packet, encrypting it and adding a MAC code if necessary
* Returns 0 on success, non-zero on failure.
*
* Returns PACKET_EAGAIN if it would block - and if it does so, you should
* call this function again as soon as it is likely that more data can be
* sent, and this function should then be called with the same argument set
* (same data pointer and same data_len) until zero or failure is returned.
*/
int
libssh2_packet_write(LIBSSH2_SESSION * session, unsigned char *data,
unsigned long data_len)
{
int blocksize =
(session->state & LIBSSH2_STATE_NEWKEYS) ? session->local.crypt->
blocksize : 8;
int padding_length;
int packet_length;
int total_length;
int free_data = 0;
#ifdef RANDOM_PADDING
int rand_max;
int seed = data[0]; /* FIXME: make this random */
#endif
struct transportpacket *p = &session->packet;
int encrypted;
int i;
ssize_t ret;
libssh2pack_t rc;
unsigned char *orgdata = data;
unsigned long orgdata_len = data_len;
debugdump(session, "libssh2_packet_write plain", data, data_len);
/* FIRST, check if we have a pending write to complete */
rc = send_existing(session, data, data_len, &ret);
if (rc || ret) {
return rc;
}
encrypted = (session->state & LIBSSH2_STATE_NEWKEYS) ? 1 : 0;
/* check if we should compress */
if (encrypted && strcmp(session->local.comp->name, "none")) {
if (session->local.comp->
comp(session, 1, &data, &data_len, LIBSSH2_PACKET_MAXCOMP,
&free_data, data, data_len, &session->local.comp_abstract)) {
return PACKET_COMPRESS; /* compression failure */
}
}
/* RFC4253 says: Note that the length of the concatenation of
'packet_length', 'padding_length', 'payload', and 'random padding'
MUST be a multiple of the cipher block size or 8, whichever is
larger. */
/* Plain math: (4 + 1 + packet_length + padding_length) % blocksize == 0 */
packet_length = data_len + 1 + 4; /* 1 is for padding_length field
4 for the packet_length field */
/* at this point we have it all except the padding */
/* first figure out our minimum padding amount to make it an even
block size */
padding_length = blocksize - (packet_length % blocksize);
/* if the padding becomes too small we add another blocksize worth
of it (taken from the original libssh2 where it didn't have any
real explanation) */
if (padding_length < 4) {
padding_length += blocksize;
}
#ifdef RANDOM_PADDING
/* FIXME: we can add padding here, but that also makes the packets
bigger etc */
/* now we can add 'blocksize' to the padding_length N number of times
(to "help thwart traffic analysis") but it must be less than 255 in
total */
rand_max = (255 - padding_length) / blocksize + 1;
padding_length += blocksize * (seed % rand_max);
#endif
packet_length += padding_length;
/* append the MAC length to the total_length size */
total_length =
packet_length + (encrypted ? session->local.mac->mac_len : 0);
/* allocate memory to store the outgoing packet in, in case we can't
send the whole one and thus need to keep it after this function
returns. */
p->outbuf = LIBSSH2_ALLOC(session, total_length);
if (!p->outbuf) {
return PACKET_ENOMEM;
}
/* store packet_length, which is the size of the whole packet except
the MAC and the packet_length field itself */
libssh2_htonu32(p->outbuf, packet_length - 4);
/* store padding_length */
p->outbuf[4] = padding_length;
/* copy the payload data */
memcpy(p->outbuf + 5, data, data_len);
/* fill the padding area with random junk */
libssh2_random(p->outbuf + 5 + data_len, padding_length);
if (free_data) {
LIBSSH2_FREE(session, data);
}
if (encrypted) {
/* Calculate MAC hash. Put the output at index packet_length,
since that size includes the whole packet. The MAC is
calculated on the entire unencrypted packet, including all
fields except the MAC field itself. */
session->local.mac->hash(session, p->outbuf + packet_length,
session->local.seqno, p->outbuf,
packet_length, NULL, 0,
&session->local.mac_abstract);
/* Encrypt the whole packet data, one block size at a time.
The MAC field is not encrypted. */
for(i = 0; i < packet_length; i += session->local.crypt->blocksize) {
unsigned char *ptr = &p->outbuf[i];
if (session->local.crypt->
crypt(session, ptr, &session->local.crypt_abstract))
return PACKET_FAIL; /* encryption failure */
}
}
session->local.seqno++;
ret = send(session->socket_fd, p->outbuf, total_length,
LIBSSH2_SOCKET_SEND_FLAGS(session));
if (ret != -1) {
debugdump(session, "libssh2_packet_write send()", p->outbuf, ret);
}
if (ret != total_length) {
if ((ret > 0) || ((ret == -1) && (errno == EAGAIN))) {
/* the whole packet could not be sent, save the rest */
p->odata = orgdata;
p->olen = orgdata_len;
p->osent = (ret == -1) ? 0 : ret;
p->ototal_num = total_length;
return PACKET_EAGAIN;
}
return PACKET_FAIL;
}
/* the whole thing got sent away */
p->odata = NULL;
p->olen = 0;
LIBSSH2_FREE(session, p->outbuf);
p->outbuf = NULL;
return PACKET_NONE; /* all is good */
}
/* {{{ libssh2_session_disconnect_ex
*/
LIBSSH2_API int
libssh2_session_disconnect_ex(LIBSSH2_SESSION * session, int reason,
const char *description, const char *lang)
{
unsigned char *s;
unsigned long descr_len = 0, lang_len = 0;
int rc;
if (session->disconnect_state == libssh2_NB_state_idle) {
_libssh2_debug(session, LIBSSH2_DBG_TRANS,
"Disconnecting: reason=%d, desc=%s, lang=%s", reason,
description, lang);
if (description) {
descr_len = strlen(description);
}
if (lang) {
lang_len = strlen(lang);
}
/* 13 = packet_type(1) + reason code(4) + descr_len(4) + lang_len(4) */
session->disconnect_data_len = descr_len + lang_len + 13;
s = session->disconnect_data =
LIBSSH2_ALLOC(session, session->disconnect_data_len);
if (!session->disconnect_data) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate memory for disconnect packet",
0);
session->disconnect_state = libssh2_NB_state_idle;
return -1;
}
*(s++) = SSH_MSG_DISCONNECT;
libssh2_htonu32(s, reason);
s += 4;
libssh2_htonu32(s, descr_len);
s += 4;
if (description) {
memcpy(s, description, descr_len);
s += descr_len;
}
libssh2_htonu32(s, lang_len);
s += 4;
if (lang) {
memcpy(s, lang, lang_len);
s += lang_len;
}
session->disconnect_state = libssh2_NB_state_created;
}
rc = libssh2_packet_write(session, session->disconnect_data,
session->disconnect_data_len);
if (rc == PACKET_EAGAIN) {
return PACKET_EAGAIN;
}
LIBSSH2_FREE(session, session->disconnect_data);
session->disconnect_data = NULL;
session->disconnect_state = libssh2_NB_state_idle;
return 0;
}
/* {{{ libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange
* Diffie Hellman Key Exchange, Group Agnostic
*/
static int libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(LIBSSH2_SESSION *session, _libssh2_bn *g, _libssh2_bn *p, int group_order,
unsigned char packet_type_init, unsigned char packet_type_reply,
unsigned char *midhash, unsigned long midhash_len)
{
unsigned char *e_packet = NULL, *s_packet = NULL, *tmp, h_sig_comp[SHA_DIGEST_LENGTH], c;
unsigned long e_packet_len, s_packet_len, tmp_len;
int ret = 0;
_libssh2_bn_ctx *ctx = _libssh2_bn_ctx_new();
_libssh2_bn *x = _libssh2_bn_init(); /* Random from client */
_libssh2_bn *e = _libssh2_bn_init(); /* g^x mod p */
_libssh2_bn *f = _libssh2_bn_init(); /* g^(Random from server) mod p */
_libssh2_bn *k = _libssh2_bn_init(); /* The shared secret: f^x mod p */
unsigned char *s, *f_value, *k_value = NULL, *h_sig;
unsigned long f_value_len, k_value_len, h_sig_len;
libssh2_sha1_ctx exchange_hash;
/* Generate x and e */
_libssh2_bn_rand(x, group_order, 0, -1);
_libssh2_bn_mod_exp(e, g, x, p, ctx);
/* Send KEX init */
e_packet_len = _libssh2_bn_bytes(e) + 6; /* packet_type(1) + String Length(4) + leading 0(1) */
if (_libssh2_bn_bits(e) % 8) {
/* Leading 00 not needed */
e_packet_len--;
}
e_packet = LIBSSH2_ALLOC(session, e_packet_len);
if (!e_packet) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Out of memory error", 0);
ret = -1;
goto clean_exit;
}
e_packet[0] = packet_type_init;
libssh2_htonu32(e_packet + 1, e_packet_len - 5);
if (_libssh2_bn_bits(e) % 8) {
_libssh2_bn_to_bin(e, e_packet + 5);
} else {
e_packet[5] = 0;
_libssh2_bn_to_bin(e, e_packet + 6);
}
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Sending KEX packet %d", (int)packet_type_init);
#endif
if (libssh2_packet_write(session, e_packet, e_packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send KEX init message", 0);
ret = -11;
goto clean_exit;
}
if (session->burn_optimistic_kexinit) {
/* The first KEX packet to come along will be the guess initially sent by the server
* That guess turned out to be wrong so we need to silently ignore it */
int burn_type;
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Waiting for badly guessed KEX packet (to be ignored)");
#endif
burn_type = libssh2_packet_burn(session);
if (burn_type <= 0) {
/* Failed to receive a packet */
ret = -1;
goto clean_exit;
}
session->burn_optimistic_kexinit = 0;
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Burnt packet of type: %02x", (unsigned int)burn_type);
#endif
}
/* Wait for KEX reply */
if (libssh2_packet_require(session, packet_type_reply, &s_packet, &s_packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_TIMEOUT, "Timed out waiting for KEX reply", 0);
ret = -1;
goto clean_exit;
}
/* Parse KEXDH_REPLY */
s = s_packet + 1;
session->server_hostkey_len = libssh2_ntohu32(s); s += 4;
session->server_hostkey = LIBSSH2_ALLOC(session, session->server_hostkey_len);
if (!session->server_hostkey) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for a copy of the host key", 0);
ret = -1;
goto clean_exit;
}
memcpy(session->server_hostkey, s, session->server_hostkey_len);
s += session->server_hostkey_len;
#if LIBSSH2_MD5
{
libssh2_md5_ctx fingerprint_ctx;
libssh2_md5_init(&fingerprint_ctx);
libssh2_md5_update(fingerprint_ctx, session->server_hostkey, session->server_hostkey_len);
libssh2_md5_final(fingerprint_ctx, session->server_hostkey_md5);
}
#ifdef LIBSSH2_DEBUG_KEX
{
char fingerprint[50], *fprint = fingerprint;
int i;
for(i = 0; i < 16; i++, fprint += 3) {
snprintf(fprint, 4, "%02x:", session->server_hostkey_md5[i]);
}
*(--fprint) = '\0';
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Server's MD5 Fingerprint: %s", fingerprint);
}
#endif /* LIBSSH2_DEBUG_KEX */
#endif /* ! LIBSSH2_MD5 */
{
libssh2_sha1_ctx fingerprint_ctx;
libssh2_sha1_init(&fingerprint_ctx);
libssh2_sha1_update (fingerprint_ctx, session->server_hostkey, session->server_hostkey_len);
libssh2_sha1_final(fingerprint_ctx, session->server_hostkey_sha1);
}
#ifdef LIBSSH2_DEBUG_KEX
{
char fingerprint[64], *fprint = fingerprint;
int i;
for(i = 0; i < 20; i++, fprint += 3) {
snprintf(fprint, 4, "%02x:", session->server_hostkey_sha1[i]);
}
*(--fprint) = '\0';
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Server's SHA1 Fingerprint: %s", fingerprint);
}
#endif /* LIBSSH2_DEBUG_KEX */
if (session->hostkey->init(session, session->server_hostkey, session->server_hostkey_len, &session->server_hostkey_abstract)) {
libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_INIT, "Unable to initialize hostkey importer", 0);
ret = -1;
goto clean_exit;
}
f_value_len = libssh2_ntohu32(s); s += 4;
f_value = s; s += f_value_len;
_libssh2_bn_from_bin(f, f_value_len, f_value);
h_sig_len = libssh2_ntohu32(s); s += 4;
h_sig = s;
/* Compute the shared secret */
_libssh2_bn_mod_exp(k, f, x, p, ctx);
k_value_len = _libssh2_bn_bytes(k) + 5;
if (_libssh2_bn_bits(k) % 8) {
/* don't need leading 00 */
k_value_len--;
}
k_value = LIBSSH2_ALLOC(session, k_value_len);
if (!k_value) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate buffer for K", 0);
ret = -1;
goto clean_exit;
}
libssh2_htonu32(k_value, k_value_len - 4);
if (_libssh2_bn_bits(k) % 8) {
_libssh2_bn_to_bin(k, k_value + 4);
} else {
k_value[4] = 0;
_libssh2_bn_to_bin(k, k_value + 5);
}
libssh2_sha1_init(&exchange_hash);
if (session->local.banner) {
libssh2_htonu32(h_sig_comp,
strlen((char *)session->local.banner) - 2);
libssh2_sha1_update(exchange_hash, h_sig_comp, 4);
libssh2_sha1_update(exchange_hash, (char *)session->local.banner,
strlen((char *)session->local.banner) - 2);
} else {
libssh2_htonu32(h_sig_comp, sizeof(LIBSSH2_SSH_DEFAULT_BANNER) - 1);
libssh2_sha1_update(exchange_hash, h_sig_comp, 4);
libssh2_sha1_update(exchange_hash, LIBSSH2_SSH_DEFAULT_BANNER,
sizeof(LIBSSH2_SSH_DEFAULT_BANNER) - 1);
}
libssh2_htonu32(h_sig_comp, strlen((char *)session->remote.banner));
libssh2_sha1_update(exchange_hash, h_sig_comp, 4);
libssh2_sha1_update(exchange_hash, session->remote.banner,
strlen((char *)session->remote.banner));
libssh2_htonu32(h_sig_comp, session->local.kexinit_len);
libssh2_sha1_update(exchange_hash, h_sig_comp, 4);
libssh2_sha1_update(exchange_hash, session->local.kexinit, session->local.kexinit_len);
libssh2_htonu32(h_sig_comp, session->remote.kexinit_len);
libssh2_sha1_update(exchange_hash, h_sig_comp, 4);
libssh2_sha1_update(exchange_hash, session->remote.kexinit, session->remote.kexinit_len);
libssh2_htonu32(h_sig_comp, session->server_hostkey_len);
libssh2_sha1_update(exchange_hash, h_sig_comp, 4);
libssh2_sha1_update(exchange_hash, session->server_hostkey, session->server_hostkey_len);
if (packet_type_init == SSH_MSG_KEX_DH_GEX_INIT) {
/* diffie-hellman-group-exchange hashes additional fields */
#ifdef LIBSSH2_DH_GEX_NEW
libssh2_htonu32(h_sig_comp, LIBSSH2_DH_GEX_MINGROUP);
libssh2_htonu32(h_sig_comp + 4, LIBSSH2_DH_GEX_OPTGROUP);
libssh2_htonu32(h_sig_comp + 8, LIBSSH2_DH_GEX_MAXGROUP);
libssh2_sha1_update(exchange_hash, h_sig_comp, 12);
#else
libssh2_htonu32(h_sig_comp, LIBSSH2_DH_GEX_OPTGROUP);
libssh2_sha1_update(exchange_hash, h_sig_comp, 4);
#endif
}
if (midhash) {
libssh2_sha1_update(exchange_hash, midhash, midhash_len);
}
libssh2_sha1_update(exchange_hash, e_packet + 1, e_packet_len - 1);
libssh2_htonu32(h_sig_comp, f_value_len);
libssh2_sha1_update(exchange_hash, h_sig_comp, 4);
libssh2_sha1_update(exchange_hash, f_value, f_value_len);
libssh2_sha1_update(exchange_hash, k_value, k_value_len);
libssh2_sha1_final(exchange_hash, h_sig_comp);
if (session->hostkey->sig_verify(session, h_sig, h_sig_len, h_sig_comp, 20, &session->server_hostkey_abstract)) {
libssh2_error(session, LIBSSH2_ERROR_HOSTKEY_SIGN, "Unable to verify hostkey signature", 0);
ret = -1;
goto clean_exit;
}
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Sending NEWKEYS message");
#endif
c = SSH_MSG_NEWKEYS;
if (libssh2_packet_write(session, &c, 1)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send NEWKEYS message", 0);
ret = -1;
goto clean_exit;
}
if (libssh2_packet_require(session, SSH_MSG_NEWKEYS, &tmp, &tmp_len)) {
libssh2_error(session, LIBSSH2_ERROR_TIMEOUT, "Timed out waiting for NEWKEYS", 0);
ret = -1;
goto clean_exit;
}
/* The first key exchange has been performed, switch to active crypt/comp/mac mode */
session->state |= LIBSSH2_STATE_NEWKEYS;
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Received NEWKEYS message");
#endif
/* This will actually end up being just packet_type(1) for this packet type anyway */
LIBSSH2_FREE(session, tmp);
if (!session->session_id) {
session->session_id = LIBSSH2_ALLOC(session, SHA_DIGEST_LENGTH);
if (!session->session_id) {
ret = -1;
goto clean_exit;
}
memcpy(session->session_id, h_sig_comp, SHA_DIGEST_LENGTH);
session->session_id_len = SHA_DIGEST_LENGTH;
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "session_id calculated");
#endif
}
/* Cleanup any existing cipher */
if (session->local.crypt->dtor) {
session->local.crypt->dtor(session, &session->local.crypt_abstract);
}
/* Calculate IV/Secret/Key for each direction */
if (session->local.crypt->init) {
unsigned char *iv = NULL, *secret = NULL;
int free_iv = 0, free_secret = 0;
LIBSSH2_KEX_METHOD_DIFFIE_HELLMAN_SHA1_HASH(iv, session->local.crypt->iv_len, "A");
LIBSSH2_KEX_METHOD_DIFFIE_HELLMAN_SHA1_HASH(secret, session->local.crypt->secret_len, "C");
if (session->local.crypt->init(session, session->local.crypt, iv, &free_iv, secret, &free_secret, 1, &session->local.crypt_abstract)) {
LIBSSH2_FREE(session, iv);
LIBSSH2_FREE(session, secret);
ret = -1;
goto clean_exit;
}
if (free_iv) {
memset(iv, 0, session->local.crypt->iv_len);
LIBSSH2_FREE(session, iv);
}
if (free_secret) {
memset(secret, 0, session->local.crypt->secret_len);
LIBSSH2_FREE(session, secret);
}
}
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Client to Server IV and Key calculated");
#endif
if (session->remote.crypt->dtor) {
/* Cleanup any existing cipher */
session->remote.crypt->dtor(session, &session->remote.crypt_abstract);
}
if (session->remote.crypt->init) {
unsigned char *iv = NULL, *secret = NULL;
int free_iv = 0, free_secret = 0;
LIBSSH2_KEX_METHOD_DIFFIE_HELLMAN_SHA1_HASH(iv, session->remote.crypt->iv_len, "B");
LIBSSH2_KEX_METHOD_DIFFIE_HELLMAN_SHA1_HASH(secret, session->remote.crypt->secret_len, "D");
if (session->remote.crypt->init(session, session->remote.crypt, iv, &free_iv, secret, &free_secret, 0, &session->remote.crypt_abstract)) {
LIBSSH2_FREE(session, iv);
LIBSSH2_FREE(session, secret);
ret = -1;
goto clean_exit;
}
if (free_iv) {
memset(iv, 0, session->remote.crypt->iv_len);
LIBSSH2_FREE(session, iv);
}
if (free_secret) {
memset(secret, 0, session->remote.crypt->secret_len);
LIBSSH2_FREE(session, secret);
}
}
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Server to Client IV and Key calculated");
#endif
if (session->local.mac->dtor) {
session->local.mac->dtor(session, &session->local.mac_abstract);
}
if (session->local.mac->init) {
unsigned char *key = NULL;
int free_key = 0;
LIBSSH2_KEX_METHOD_DIFFIE_HELLMAN_SHA1_HASH(key, session->local.mac->key_len, "E");
session->local.mac->init(session, key, &free_key, &session->local.mac_abstract);
if (free_key) {
memset(key, 0, session->local.mac->key_len);
LIBSSH2_FREE(session, key);
}
}
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Client to Server HMAC Key calculated");
#endif
if (session->remote.mac->dtor) {
session->remote.mac->dtor(session, &session->remote.mac_abstract);
}
if (session->remote.mac->init) {
unsigned char *key = NULL;
int free_key = 0;
LIBSSH2_KEX_METHOD_DIFFIE_HELLMAN_SHA1_HASH(key, session->remote.mac->key_len, "F");
session->remote.mac->init(session, key, &free_key, &session->remote.mac_abstract);
if (free_key) {
memset(key, 0, session->remote.mac->key_len);
LIBSSH2_FREE(session, key);
}
}
#ifdef LIBSSH2_DEBUG_KEX
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Server to Client HMAC Key calculated");
#endif
clean_exit:
_libssh2_bn_free(x);
_libssh2_bn_free(e);
_libssh2_bn_free(f);
_libssh2_bn_free(k);
_libssh2_bn_ctx_free(ctx);
if (e_packet) {
LIBSSH2_FREE(session, e_packet);
}
if (s_packet) {
LIBSSH2_FREE(session, s_packet);
}
if (k_value) {
LIBSSH2_FREE(session, k_value);
}
if (session->server_hostkey) {
LIBSSH2_FREE(session, session->server_hostkey);
session->server_hostkey = NULL;
}
return ret;
}
/* {{{ libssh2_packet_x11_open
* Accept a forwarded X11 connection
*/
inline int libssh2_packet_x11_open(LIBSSH2_SESSION *session, unsigned char *data, unsigned long datalen)
{
int failure_code = 2; /* SSH_OPEN_CONNECT_FAILED */
unsigned char *s = data + (sizeof("x11") - 1) + 5;
unsigned long packet_len = 17 + (sizeof("X11 Forward Unavailable") - 1);
unsigned char *p, packet[17 + (sizeof("X11 Forward Unavailable") - 1)];
/* packet_type(1) + channel(4) + reason(4) + descr(4) + lang(4) */
LIBSSH2_CHANNEL *channel;
unsigned long sender_channel, initial_window_size, packet_size;
unsigned char *shost;
unsigned long sport, shost_len;
sender_channel = libssh2_ntohu32(s); s += 4;
initial_window_size = libssh2_ntohu32(s); s += 4;
packet_size = libssh2_ntohu32(s); s += 4;
shost_len = libssh2_ntohu32(s); s += 4;
shost = s; s += shost_len;
sport = libssh2_ntohu32(s); s += 4;
#ifdef LIBSSH2_DEBUG_CONNECTION
_libssh2_debug(session, LIBSSH2_DBG_CONN, "X11 Connection Received from %s:%ld on channel %lu", shost, sport, sender_channel);
#endif
if (session->x11) {
channel = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_CHANNEL));
if (!channel) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate a channel for new connection", 0);
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
goto x11_exit;
}
memset(channel, 0, sizeof(LIBSSH2_CHANNEL));
channel->session = session;
channel->channel_type_len = sizeof("x11") - 1;
channel->channel_type = LIBSSH2_ALLOC(session, channel->channel_type_len + 1);
if (!channel->channel_type) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate a channel for new connection", 0);
LIBSSH2_FREE(session, channel);
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
goto x11_exit;
}
memcpy(channel->channel_type, "x11", channel->channel_type_len + 1);
channel->remote.id = sender_channel;
channel->remote.window_size_initial = LIBSSH2_CHANNEL_WINDOW_DEFAULT;
channel->remote.window_size = LIBSSH2_CHANNEL_WINDOW_DEFAULT;
channel->remote.packet_size = LIBSSH2_CHANNEL_PACKET_DEFAULT;
channel->local.id = libssh2_channel_nextid(session);
channel->local.window_size_initial = initial_window_size;
channel->local.window_size = initial_window_size;
channel->local.packet_size = packet_size;
#ifdef LIBSSH2_DEBUG_CONNECTION
_libssh2_debug(session, LIBSSH2_DBG_CONN, "X11 Connection established: channel %lu/%lu win %lu/%lu packet %lu/%lu",
channel->local.id, channel->remote.id,
channel->local.window_size, channel->remote.window_size,
channel->local.packet_size, channel->remote.packet_size);
#endif
p = packet;
*(p++) = SSH_MSG_CHANNEL_OPEN_CONFIRMATION;
libssh2_htonu32(p, channel->remote.id); p += 4;
libssh2_htonu32(p, channel->local.id); p += 4;
libssh2_htonu32(p, channel->remote.window_size_initial); p += 4;
libssh2_htonu32(p, channel->remote.packet_size); p += 4;
if (libssh2_packet_write(session, packet, 17)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send channel open confirmation", 0);
return -1;
}
/* Link the channel into the session */
if (session->channels.tail) {
session->channels.tail->next = channel;
channel->prev = session->channels.tail;
} else {
session->channels.head = channel;
channel->prev = NULL;
}
channel->next = NULL;
session->channels.tail = channel;
/* Pass control to the callback, they may turn right around and free the channel, or actually use it */
LIBSSH2_X11_OPEN(channel, shost, sport);
return 0;
} else {
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
}
x11_exit:
p = packet;
*(p++) = SSH_MSG_CHANNEL_OPEN_FAILURE;
libssh2_htonu32(p, sender_channel); p += 4;
libssh2_htonu32(p, failure_code); p += 4;
libssh2_htonu32(p, sizeof("X11 Forward Unavailable") - 1); p += 4;
memcpy(s, "X11 Forward Unavailable", sizeof("X11 Forward Unavailable") - 1); p += sizeof("X11 Forward Unavailable") - 1;
libssh2_htonu32(p, 0);
if (libssh2_packet_write(session, packet, packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send open failure", 0);
return -1;
}
return 0;
}
/* {{{ libssh2_userauth_keyboard_interactive
* Authenticate using a challenge-response authentication
*/
LIBSSH2_API int libssh2_userauth_keyboard_interactive_ex(LIBSSH2_SESSION *session, const char *username, unsigned int username_len,
LIBSSH2_USERAUTH_KBDINT_RESPONSE_FUNC((*response_callback)))
{
unsigned char *s, *data; /* packet */
unsigned long packet_len;
packet_len = 1 /* byte SSH_MSG_USERAUTH_REQUEST */
+ 4 + username_len /* string user name (ISO-10646 UTF-8, as defined in [RFC-3629]) */
+ 4 + 14 /* string service name (US-ASCII) */
+ 4 + 20 /* string "keyboard-interactive" (US-ASCII) */
+ 4 + 0 /* string language tag (as defined in [RFC-3066]) */
+ 4 + 0 /* string submethods (ISO-10646 UTF-8) */
;
if (!(data = s = LIBSSH2_ALLOC(session, packet_len))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive authentication", 0);
return -1;
}
*s++ = SSH_MSG_USERAUTH_REQUEST;
/* user name */
libssh2_htonu32(s, username_len); s += 4;
memcpy(s, username, username_len); s += username_len;
/* service name */
libssh2_htonu32(s, sizeof("ssh-connection") - 1); s += 4;
memcpy(s, "ssh-connection", sizeof("ssh-connection") - 1); s += sizeof("ssh-connection") - 1;
/* "keyboard-interactive" */
libssh2_htonu32(s, sizeof("keyboard-interactive") - 1); s += 4;
memcpy(s, "keyboard-interactive", sizeof("keyboard-interactive") - 1); s += sizeof("keyboard-interactive") - 1;
/* language tag */
libssh2_htonu32(s, 0); s += 4;
/* submethods */
libssh2_htonu32(s, 0); s += 4;
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Attempting keyboard-interactive authentication");
#endif
if (libssh2_packet_write(session, data, packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send keyboard-interactive request", 0);
LIBSSH2_FREE(session, data);
return -1;
}
LIBSSH2_FREE(session, data);
for (;;) {
unsigned char reply_codes[4] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, SSH_MSG_USERAUTH_INFO_REQUEST, 0 };
unsigned int auth_name_len;
char* auth_name = NULL;
unsigned auth_instruction_len;
char* auth_instruction = NULL;
unsigned int language_tag_len;
unsigned long data_len;
unsigned int num_prompts = 0;
unsigned int i;
int auth_failure = 1;
LIBSSH2_USERAUTH_KBDINT_PROMPT* prompts = NULL;
LIBSSH2_USERAUTH_KBDINT_RESPONSE* responses = NULL;
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
return -1;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Keyboard-interactive authentication successful");
#endif
LIBSSH2_FREE(session, data);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return 0;
}
if (data[0] == SSH_MSG_USERAUTH_FAILURE) {
LIBSSH2_FREE(session, data);
return -1;
}
/* server requested PAM-like conversation */
s = data + 1;
/* string name (ISO-10646 UTF-8) */
auth_name_len = libssh2_ntohu32(s); s += 4;
if (!(auth_name = LIBSSH2_ALLOC(session, auth_name_len))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive 'name' request field", 0);
goto cleanup;
}
memcpy(auth_name, s, auth_name_len); s += auth_name_len;
/* string instruction (ISO-10646 UTF-8) */
auth_instruction_len = libssh2_ntohu32(s); s += 4;
if (!(auth_instruction = LIBSSH2_ALLOC(session, auth_instruction_len))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive 'instruction' request field", 0);
goto cleanup;
}
memcpy(auth_instruction, s, auth_instruction_len); s += auth_instruction_len;
/* string language tag (as defined in [RFC-3066]) */
language_tag_len = libssh2_ntohu32(s); s += 4;
/* ignoring this field as deprecated */ s += language_tag_len;
/* int num-prompts */
num_prompts = libssh2_ntohu32(s); s += 4;
prompts = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_USERAUTH_KBDINT_PROMPT) * num_prompts);
if (!prompts) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive prompts array", 0);
goto cleanup;
}
memset(prompts, 0, sizeof(LIBSSH2_USERAUTH_KBDINT_PROMPT) * num_prompts);
responses = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_USERAUTH_KBDINT_RESPONSE) * num_prompts);
if (!responses) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive responses array", 0);
goto cleanup;
}
memset(responses, 0, sizeof(LIBSSH2_USERAUTH_KBDINT_RESPONSE) * num_prompts);
for(i = 0; i != num_prompts; ++i) {
/* string prompt[1] (ISO-10646 UTF-8) */
prompts[i].length = libssh2_ntohu32(s); s += 4;
if (!(prompts[i].text = LIBSSH2_ALLOC(session, prompts[i].length))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive prompt message", 0);
goto cleanup;
}
memcpy(prompts[i].text, s, prompts[i].length); s += prompts[i].length;
/* boolean echo[1] */
prompts[i].echo = *s++;
}
response_callback(auth_name, auth_name_len, auth_instruction, auth_instruction_len, num_prompts, prompts, responses, &session->abstract);
#ifdef LIBSSH2_DEBUG_USERAUTH
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Keyboard-interactive response callback function invoked");
#endif
packet_len = 1 /* byte SSH_MSG_USERAUTH_INFO_RESPONSE */
+ 4 /* int num-responses */
;
for (i = 0; i != num_prompts; ++i) {
packet_len += 4 + responses[i].length; /* string response[1] (ISO-10646 UTF-8) */
}
if (!(data = s = LIBSSH2_ALLOC(session, packet_len))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive response packet", 0);
goto cleanup;
}
*s = SSH_MSG_USERAUTH_INFO_RESPONSE; s++;
libssh2_htonu32(s, num_prompts); s += 4;
for (i = 0; i != num_prompts; ++i) {
libssh2_htonu32(s, responses[i].length); s += 4;
memcpy(s, responses[i].text, responses[i].length); s += responses[i].length;
}
if (libssh2_packet_write(session, data, packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-keyboard-interactive request", 0);
goto cleanup;
}
auth_failure = 0;
cleanup:
/* It's safe to clean all the data here, because unallocated pointers
* are filled by zeroes
*/
LIBSSH2_FREE(session, data);
if (prompts) {
for (i = 0; i != num_prompts; ++i) {
LIBSSH2_FREE(session, prompts[i].text);
}
}
if (responses) {
for (i = 0; i != num_prompts; ++i) {
LIBSSH2_FREE(session, responses[i].text);
}
}
LIBSSH2_FREE(session, prompts);
LIBSSH2_FREE(session, responses);
if (auth_failure) {
return -1;
}
}
}
/* {{{ libssh2_publickey_add_ex
* Add a new public key entry
*/
LIBSSH2_API int libssh2_publickey_add_ex(LIBSSH2_PUBLICKEY *pkey, const unsigned char *name, unsigned long name_len,
const unsigned char *blob, unsigned long blob_len, char overwrite,
unsigned long num_attrs, libssh2_publickey_attribute attrs[])
{
LIBSSH2_CHANNEL *channel = pkey->channel;
LIBSSH2_SESSION *session = channel->session;
unsigned char *packet = NULL, *s;
unsigned long i, packet_len = 19 + name_len + blob_len;
unsigned char *comment = NULL;
unsigned long comment_len = 0;
/* packet_len(4) +
add_len(4) +
"add"(3) +
name_len(4) +
{name}
blob_len(4) +
{blob} */
#ifdef LIBSSH2_DEBUG_PUBLICKEY
_libssh2_debug(session, LIBSSH2_DBG_PUBLICKEY, "Adding %s pubickey", name);
#endif
if (pkey->version == 1) {
for(i = 0; i < num_attrs; i++) {
/* Search for a comment attribute */
if (attrs[i].name_len == (sizeof("comment") - 1) &&
strncmp(attrs[i].name, "comment", sizeof("comment") - 1) == 0) {
comment = attrs[i].value;
comment_len = attrs[i].value_len;
break;
}
}
packet_len += 4 + comment_len;
} else {
packet_len += 5; /* overwrite(1) + attribute_count(4) */
for(i = 0; i < num_attrs; i++) {
packet_len += 9 + attrs[i].name_len + attrs[i].value_len;
/* name_len(4) + value_len(4) + mandatory(1) */
}
}
packet = LIBSSH2_ALLOC(session, packet_len);
if (!packet) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for publickey \"add\" packet", 0);
return -1;
}
s = packet;
libssh2_htonu32(s, packet_len - 4); s += 4;
libssh2_htonu32(s, sizeof("add") - 1); s += 4;
memcpy(s, "add", sizeof("add") - 1); s += sizeof("add") - 1;
if (pkey->version == 1) {
libssh2_htonu32(s, comment_len); s += 4;
if (comment) {
memcpy(s, comment, comment_len); s += comment_len;
}
libssh2_htonu32(s, name_len); s += 4;
memcpy(s, name, name_len); s += name_len;
libssh2_htonu32(s, blob_len); s += 4;
memcpy(s, blob, blob_len); s += blob_len;
} else {
/* Version == 2 */
libssh2_htonu32(s, name_len); s += 4;
memcpy(s, name, name_len); s += name_len;
libssh2_htonu32(s, blob_len); s += 4;
memcpy(s, blob, blob_len); s += blob_len;
*(s++) = overwrite ? 0xFF : 0;
libssh2_htonu32(s, num_attrs); s += 4;
for(i = 0; i < num_attrs; i++) {
libssh2_htonu32(s, attrs[i].name_len); s += 4;
memcpy(s, attrs[i].name, attrs[i].name_len); s += attrs[i].name_len;
libssh2_htonu32(s, attrs[i].value_len); s += 4;
memcpy(s, attrs[i].value, attrs[i].value_len); s += attrs[i].value_len;
*(s++) = attrs[i].mandatory ? 0xFF : 0;
}
}
#ifdef LIBSSH2_DEBUG_PUBLICKEY
_libssh2_debug(session, LIBSSH2_DBG_PUBLICKEY, "Sending publickey \"add\" packet: type=%s blob_len=%ld num_attrs=%ld", name, blob_len, num_attrs);
#endif
if ((s - packet) != libssh2_channel_write(channel, packet, (s - packet))) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send publickey add packet", 0);
LIBSSH2_FREE(session, packet);
return -1;
}
LIBSSH2_FREE(session, packet);
packet = NULL;
return libssh2_publickey_response_success(pkey);
}
/* {{{ libssh2_publickey_init
* Startup the publickey subsystem
*/
LIBSSH2_API LIBSSH2_PUBLICKEY *libssh2_publickey_init(LIBSSH2_SESSION *session)
{
LIBSSH2_PUBLICKEY *pkey = NULL;
LIBSSH2_CHANNEL *channel = NULL;
unsigned char buffer[19];
/* packet_len(4) +
version_len(4) +
"version"(7) +
version_num(4) */
unsigned char *s, *data = NULL;
unsigned long data_len;
int response;
#ifdef LIBSSH2_DEBUG_PUBLICKEY
_libssh2_debug(session, LIBSSH2_DBG_PUBLICKEY, "Initializing publickey subsystem");
#endif
channel = libssh2_channel_open_session(session);
if (!channel) {
libssh2_error(session, LIBSSH2_ERROR_CHANNEL_FAILURE, "Unable to startup channel", 0);
goto err_exit;
}
if (libssh2_channel_subsystem(channel, "publickey")) {
libssh2_error(session, LIBSSH2_ERROR_CHANNEL_FAILURE, "Unable to request publickey subsystem", 0);
goto err_exit;
}
libssh2_channel_set_blocking(channel, 1);
libssh2_channel_handle_extended_data(channel, LIBSSH2_CHANNEL_EXTENDED_DATA_IGNORE);
pkey = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_PUBLICKEY));
if (!pkey) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate a new publickey structure", 0);
goto err_exit;
}
pkey->channel = channel;
pkey->version = 0;
s = buffer;
libssh2_htonu32(s, 4 + (sizeof("version") - 1) + 4); s += 4;
libssh2_htonu32(s, sizeof("version") - 1); s += 4;
memcpy(s, "version", sizeof("version") - 1); s += sizeof("version") - 1;
libssh2_htonu32(s, LIBSSH2_PUBLICKEY_VERSION); s += 4;
#ifdef LIBSSH2_DEBUG_PUBLICKEY
_libssh2_debug(session, LIBSSH2_DBG_PUBLICKEY, "Sending publickey version packet advertising version %d support", (int)LIBSSH2_PUBLICKEY_VERSION);
#endif
if ((s - buffer) != libssh2_channel_write(channel, buffer, (s - buffer))) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send publickey version packet", 0);
goto err_exit;
}
while (1) {
if (libssh2_publickey_packet_receive(pkey, &data, &data_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_TIMEOUT, "Timeout waiting for response from publickey subsystem", 0);
goto err_exit;
}
s = data;
if ((response = libssh2_publickey_response_id(&s, data_len)) < 0) {
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_PROTOCOL, "Invalid publickey subsystem response code", 0);
goto err_exit;
}
switch (response) {
case LIBSSH2_PUBLICKEY_RESPONSE_STATUS:
/* Error */
{
unsigned long status, descr_len, lang_len;
unsigned char *descr, *lang;
status = libssh2_ntohu32(s); s += 4;
descr_len = libssh2_ntohu32(s); s += 4;
descr = s; s += descr_len;
lang_len = libssh2_ntohu32(s); s += 4;
lang = s; s += lang_len;
if (s > data + data_len) {
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_PROTOCOL, "Malformed publickey subsystem packet", 0);
goto err_exit;
}
libssh2_publickey_status_error(NULL, session, status, descr, descr_len);
goto err_exit;
}
case LIBSSH2_PUBLICKEY_RESPONSE_VERSION:
/* What we want */
pkey->version = libssh2_ntohu32(s);
if (pkey->version > LIBSSH2_PUBLICKEY_VERSION) {
#ifdef LIBSSH2_DEBUG_PUBLICKEY
_libssh2_debug(session, LIBSSH2_DBG_PUBLICKEY, "Truncating remote publickey version from %lu", pkey->version);
#endif
pkey->version = LIBSSH2_PUBLICKEY_VERSION;
}
#ifdef LIBSSH2_DEBUG_PUBLICKEY
_libssh2_debug(session, LIBSSH2_DBG_PUBLICKEY, "Enabling publickey subsystem version %lu", pkey->version);
#endif
LIBSSH2_FREE(session, data);
return pkey;
default:
/* Unknown/Unexpected */
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_PROTOCOL, "Unexpected publickey subsystem response, ignoring", 0);
LIBSSH2_FREE(session, data);
data = NULL;
}
}
/* Never reached except by direct goto */
err_exit:
if (channel) {
libssh2_channel_close(channel);
}
if (pkey) {
LIBSSH2_FREE(session, pkey);
}
if (data) {
LIBSSH2_FREE(session, data);
}
return NULL;
}
/* {{{ libssh2_packet_queue_listener
* Queue a connection request for a listener
*/
static inline int
libssh2_packet_queue_listener(LIBSSH2_SESSION * session, unsigned char *data,
unsigned long datalen,
packet_queue_listener_state_t * listen_state)
{
/*
* Look for a matching listener
*/
unsigned char *s = data + (sizeof("forwarded-tcpip") - 1) + 5;
/* 17 = packet_type(1) + channel(4) + reason(4) + descr(4) + lang(4) */
unsigned long packet_len = 17 + (sizeof(FwdNotReq) - 1);
unsigned char *p;
LIBSSH2_LISTENER *listen = session->listeners;
char failure_code = 1; /* SSH_OPEN_ADMINISTRATIVELY_PROHIBITED */
int rc;
(void) datalen;
if (listen_state->state == libssh2_NB_state_idle) {
listen_state->sender_channel = libssh2_ntohu32(s);
s += 4;
listen_state->initial_window_size = libssh2_ntohu32(s);
s += 4;
listen_state->packet_size = libssh2_ntohu32(s);
s += 4;
listen_state->host_len = libssh2_ntohu32(s);
s += 4;
listen_state->host = s;
s += listen_state->host_len;
listen_state->port = libssh2_ntohu32(s);
s += 4;
listen_state->shost_len = libssh2_ntohu32(s);
s += 4;
listen_state->shost = s;
s += listen_state->shost_len;
listen_state->sport = libssh2_ntohu32(s);
s += 4;
_libssh2_debug(session, LIBSSH2_DBG_CONN,
"Remote received connection from %s:%ld to %s:%ld",
listen_state->shost, listen_state->sport,
listen_state->host, listen_state->port);
listen_state->state = libssh2_NB_state_allocated;
}
if (listen_state->state != libssh2_NB_state_sent) {
while (listen) {
if ((listen->port == (int) listen_state->port) &&
(strlen(listen->host) == listen_state->host_len) &&
(memcmp
(listen->host, listen_state->host,
listen_state->host_len) == 0)) {
/* This is our listener */
LIBSSH2_CHANNEL *channel, *last_queued = listen->queue;
last_queued = listen->queue;
if (listen_state->state == libssh2_NB_state_allocated) {
if (listen->queue_maxsize &&
(listen->queue_maxsize <= listen->queue_size)) {
/* Queue is full */
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
_libssh2_debug(session, LIBSSH2_DBG_CONN,
"Listener queue full, ignoring");
listen_state->state = libssh2_NB_state_sent;
break;
}
channel = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_CHANNEL));
if (!channel) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate a channel for new connection",
0);
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
listen_state->state = libssh2_NB_state_sent;
break;
}
memset(channel, 0, sizeof(LIBSSH2_CHANNEL));
channel->session = session;
channel->channel_type_len = sizeof("forwarded-tcpip") - 1;
channel->channel_type = LIBSSH2_ALLOC(session,
channel->
channel_type_len +
1);
if (!channel->channel_type) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate a channel for new connection",
0);
LIBSSH2_FREE(session, channel);
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
listen_state->state = libssh2_NB_state_sent;
break;
}
memcpy(channel->channel_type, "forwarded-tcpip",
channel->channel_type_len + 1);
channel->remote.id = listen_state->sender_channel;
channel->remote.window_size_initial =
LIBSSH2_CHANNEL_WINDOW_DEFAULT;
channel->remote.window_size =
LIBSSH2_CHANNEL_WINDOW_DEFAULT;
channel->remote.packet_size =
LIBSSH2_CHANNEL_PACKET_DEFAULT;
channel->local.id = libssh2_channel_nextid(session);
channel->local.window_size_initial =
listen_state->initial_window_size;
channel->local.window_size =
listen_state->initial_window_size;
channel->local.packet_size = listen_state->packet_size;
_libssh2_debug(session, LIBSSH2_DBG_CONN,
"Connection queued: channel %lu/%lu win %lu/%lu packet %lu/%lu",
channel->local.id, channel->remote.id,
channel->local.window_size,
channel->remote.window_size,
channel->local.packet_size,
channel->remote.packet_size);
p = listen_state->packet;
*(p++) = SSH_MSG_CHANNEL_OPEN_CONFIRMATION;
libssh2_htonu32(p, channel->remote.id);
p += 4;
libssh2_htonu32(p, channel->local.id);
p += 4;
libssh2_htonu32(p, channel->remote.window_size_initial);
p += 4;
libssh2_htonu32(p, channel->remote.packet_size);
p += 4;
listen_state->state = libssh2_NB_state_created;
}
if (listen_state->state == libssh2_NB_state_created) {
rc = libssh2_packet_write(session, listen_state->packet,
17);
if (rc == PACKET_EAGAIN) {
return PACKET_EAGAIN;
} else if (rc) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
"Unable to send channel open confirmation",
0);
listen_state->state = libssh2_NB_state_idle;
return -1;
}
/* Link the channel into the end of the queue list */
if (!last_queued) {
listen->queue = channel;
listen_state->state = libssh2_NB_state_idle;
return 0;
}
while (last_queued->next) {
last_queued = last_queued->next;
}
last_queued->next = channel;
channel->prev = last_queued;
listen->queue_size++;
listen_state->state = libssh2_NB_state_idle;
return 0;
}
}
listen = listen->next;
}
listen_state->state = libssh2_NB_state_sent;
}
/* We're not listening to you */
{
p = listen_state->packet;
*(p++) = SSH_MSG_CHANNEL_OPEN_FAILURE;
libssh2_htonu32(p, listen_state->sender_channel);
p += 4;
libssh2_htonu32(p, failure_code);
p += 4;
libssh2_htonu32(p, sizeof(FwdNotReq) - 1);
p += 4;
memcpy(s, FwdNotReq, sizeof(FwdNotReq) - 1);
p += sizeof(FwdNotReq) - 1;
libssh2_htonu32(p, 0);
rc = libssh2_packet_write(session, listen_state->packet, packet_len);
if (rc == PACKET_EAGAIN) {
return PACKET_EAGAIN;
} else if (rc) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
"Unable to send open failure", 0);
listen_state->state = libssh2_NB_state_idle;
return -1;
}
listen_state->state = libssh2_NB_state_idle;
return 0;
}
}
/* {{{ libssh2_packet_x11_open
* Accept a forwarded X11 connection
*/
static inline int
libssh2_packet_x11_open(LIBSSH2_SESSION * session, unsigned char *data,
unsigned long datalen,
packet_x11_open_state_t * x11open_state)
{
int failure_code = 2; /* SSH_OPEN_CONNECT_FAILED */
unsigned char *s = data + (sizeof("x11") - 1) + 5;
/* 17 = packet_type(1) + channel(4) + reason(4) + descr(4) + lang(4) */
unsigned long packet_len = 17 + (sizeof(X11FwdUnAvil) - 1);
unsigned char *p;
LIBSSH2_CHANNEL *channel;
int rc;
(void) datalen;
if (x11open_state->state == libssh2_NB_state_idle) {
x11open_state->sender_channel = libssh2_ntohu32(s);
s += 4;
x11open_state->initial_window_size = libssh2_ntohu32(s);
s += 4;
x11open_state->packet_size = libssh2_ntohu32(s);
s += 4;
x11open_state->shost_len = libssh2_ntohu32(s);
s += 4;
x11open_state->shost = s;
s += x11open_state->shost_len;
x11open_state->sport = libssh2_ntohu32(s);
s += 4;
_libssh2_debug(session, LIBSSH2_DBG_CONN,
"X11 Connection Received from %s:%ld on channel %lu",
x11open_state->shost, x11open_state->sport,
x11open_state->sender_channel);
x11open_state->state = libssh2_NB_state_allocated;
}
if (session->x11) {
if (x11open_state->state == libssh2_NB_state_allocated) {
channel = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_CHANNEL));
if (!channel) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate a channel for new connection",
0);
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
goto x11_exit;
}
memset(channel, 0, sizeof(LIBSSH2_CHANNEL));
channel->session = session;
channel->channel_type_len = sizeof("x11") - 1;
channel->channel_type = LIBSSH2_ALLOC(session,
channel->channel_type_len +
1);
if (!channel->channel_type) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate a channel for new connection",
0);
LIBSSH2_FREE(session, channel);
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
goto x11_exit;
}
memcpy(channel->channel_type, "x11",
channel->channel_type_len + 1);
channel->remote.id = x11open_state->sender_channel;
channel->remote.window_size_initial =
LIBSSH2_CHANNEL_WINDOW_DEFAULT;
channel->remote.window_size = LIBSSH2_CHANNEL_WINDOW_DEFAULT;
channel->remote.packet_size = LIBSSH2_CHANNEL_PACKET_DEFAULT;
channel->local.id = libssh2_channel_nextid(session);
channel->local.window_size_initial =
x11open_state->initial_window_size;
channel->local.window_size = x11open_state->initial_window_size;
channel->local.packet_size = x11open_state->packet_size;
_libssh2_debug(session, LIBSSH2_DBG_CONN,
"X11 Connection established: channel %lu/%lu win %lu/%lu packet %lu/%lu",
channel->local.id, channel->remote.id,
channel->local.window_size,
channel->remote.window_size,
channel->local.packet_size,
channel->remote.packet_size);
p = x11open_state->packet;
*(p++) = SSH_MSG_CHANNEL_OPEN_CONFIRMATION;
libssh2_htonu32(p, channel->remote.id);
p += 4;
libssh2_htonu32(p, channel->local.id);
p += 4;
libssh2_htonu32(p, channel->remote.window_size_initial);
p += 4;
libssh2_htonu32(p, channel->remote.packet_size);
p += 4;
x11open_state->state = libssh2_NB_state_created;
}
if (x11open_state->state == libssh2_NB_state_created) {
rc = libssh2_packet_write(session, x11open_state->packet, 17);
if (rc == PACKET_EAGAIN) {
return PACKET_EAGAIN;
} else if (rc) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
"Unable to send channel open confirmation", 0);
x11open_state->state = libssh2_NB_state_idle;
return -1;
}
/* Link the channel into the session */
if (session->channels.tail) {
session->channels.tail->next = channel;
channel->prev = session->channels.tail;
} else {
session->channels.head = channel;
channel->prev = NULL;
}
channel->next = NULL;
session->channels.tail = channel;
/*
* Pass control to the callback, they may turn right around and
* free the channel, or actually use it
*/
LIBSSH2_X11_OPEN(channel, (char *) x11open_state->shost,
x11open_state->sport);
x11open_state->state = libssh2_NB_state_idle;
return 0;
}
} else {
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
}
x11_exit:
p = x11open_state->packet;
*(p++) = SSH_MSG_CHANNEL_OPEN_FAILURE;
libssh2_htonu32(p, x11open_state->sender_channel);
p += 4;
libssh2_htonu32(p, failure_code);
p += 4;
libssh2_htonu32(p, sizeof(X11FwdUnAvil) - 1);
p += 4;
memcpy(s, X11FwdUnAvil, sizeof(X11FwdUnAvil) - 1);
p += sizeof(X11FwdUnAvil) - 1;
libssh2_htonu32(p, 0);
rc = libssh2_packet_write(session, x11open_state->packet, packet_len);
if (rc == PACKET_EAGAIN) {
return PACKET_EAGAIN;
} else if (rc) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
"Unable to send open failure", 0);
x11open_state->state = libssh2_NB_state_idle;
return -1;
}
x11open_state->state = libssh2_NB_state_idle;
return 0;
}
/* {{{ libssh2_packet_write
* Send a packet, encrypting it and adding a MAC code if necessary
* Returns 0 on success, non-zero on failure
*/
int libssh2_packet_write(LIBSSH2_SESSION *session, unsigned char *data, unsigned long data_len)
{
unsigned long packet_length = data_len + 1;
unsigned long block_size = (session->state & LIBSSH2_STATE_NEWKEYS) ? session->local.crypt->blocksize : 8;
/* At this point packet_length doesn't include the packet_len field itself */
unsigned long padding_length;
int free_data = 0;
unsigned char buf[246]; /* 6 byte header plus max padding size(240) */
#ifdef LIBSSH2_DEBUG_TRANSPORT
{
/* Show a hint of what's being sent */
char excerpt[32];
int ex_len = 0, db_ofs = 0;
for (; ex_len < 24 && db_ofs < data_len; ex_len += 3, db_ofs++) snprintf(excerpt + ex_len, 4, "%02X ", data[db_ofs]);
_libssh2_debug(session, LIBSSH2_DBG_TRANS, "Sending packet type %d, length=%lu, %s", (int)data[0], data_len, excerpt);
}
#endif
if ((session->state & LIBSSH2_STATE_NEWKEYS) &&
strcmp(session->local.comp->name, "none")) {
if (session->local.comp->comp(session, 1, &data, &data_len, LIBSSH2_PACKET_MAXCOMP, &free_data, data, data_len, &session->local.comp_abstract)) {
return -1;
}
#ifdef LIBSSH2_DEBUG_TRANSPORT
_libssh2_debug(session, LIBSSH2_DBG_TRANS, "Compressed payload to %lu bytes", data_len);
#endif
}
#ifndef WIN32
fcntl(session->socket_fd, F_SETFL, 0);
#else
{
u_long non_block = FALSE;
ioctlsocket(session->socket_fd, FIONBIO, &non_block);
}
#endif
packet_length = data_len + 1; /* padding_length(1) -- MAC doesn't count -- Padding to be added soon */
padding_length = block_size - ((packet_length + 4) % block_size);
if (padding_length < 4) {
padding_length += block_size;
}
/* TODO: Maybe add 1 or 2 times block_size to padding_length randomly -- shake things up a bit... */
packet_length += padding_length;
libssh2_htonu32(buf, packet_length);
buf[4] = padding_length;
#ifdef LIBSSH2_DEBUG_TRANSPORT
_libssh2_debug(session, LIBSSH2_DBG_TRANS, "Sending packet with total length %lu (%lu bytes padding)", packet_length, padding_length);
#endif
if (session->state & LIBSSH2_STATE_NEWKEYS) {
/* Encryption is in effect */
unsigned char *encbuf, *s;
int ret;
/* Safely ignored in CUSTOM cipher mode */
EVP_CIPHER_CTX *ctx = (EVP_CIPHER_CTX *)session->local.crypt_abstract;
/* include packet_length(4) itself and room for the hash at the end */
encbuf = LIBSSH2_ALLOC(session, 4 + packet_length + session->local.mac->mac_len);
if (!encbuf) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate encryption buffer", 0);
if (free_data) {
LIBSSH2_FREE(session, data);
}
return -1;
}
/* Copy packet to encoding buffer */
memcpy(encbuf, buf, 5);
memcpy(encbuf + 5, data, data_len);
RAND_bytes(encbuf + 5 + data_len, padding_length);
if (free_data) {
LIBSSH2_FREE(session, data);
}
/* Calculate MAC hash */
session->local.mac->hash(session, encbuf + 4 + packet_length , session->local.seqno, encbuf, 4 + packet_length, NULL, 0, &session->local.mac_abstract);
/* Encrypt data */
for(s = encbuf; (s - encbuf) < (4 + packet_length) ; s += session->local.crypt->blocksize) {
if (session->local.crypt->flags & LIBSSH2_CRYPT_METHOD_FLAG_EVP) {
EVP_Cipher(ctx, buf, s, session->local.crypt->blocksize);
memcpy(s, buf, session->local.crypt->blocksize);
} else {
session->local.crypt->crypt(session, s, &session->local.crypt_abstract);
}
}
session->local.seqno++;
/* Send It */
ret = ((4 + packet_length + session->local.mac->mac_len) == send(session->socket_fd, encbuf, 4 + packet_length + session->local.mac->mac_len, LIBSSH2_SOCKET_SEND_FLAGS(session))) ? 0 : -1;
/* Cleanup environment */
LIBSSH2_FREE(session, encbuf);
return ret;
} else { /* LIBSSH2_ENDPOINT_CRYPT_NONE */
/* Simplified write for non-encrypted mode */
struct iovec data_vector[3];
/* Using vectors means we don't have to alloc a new buffer -- a byte saved is a byte earned
* No MAC during unencrypted phase
*/
data_vector[0].iov_base = buf;
data_vector[0].iov_len = 5;
data_vector[1].iov_base = (char*)data;
data_vector[1].iov_len = data_len;
data_vector[2].iov_base = buf + 5;
data_vector[2].iov_len = padding_length;
session->local.seqno++;
/* Ignore this, it can't actually happen :) */
if (free_data) {
LIBSSH2_FREE(session, data);
}
return ((packet_length + 4) == writev(session->socket_fd, data_vector, 3)) ? 0 : 1;
}
}
/* {{{ libssh2_publickey_list_fetch
* Fetch a list of supported public key from a server
*/
LIBSSH2_API int libssh2_publickey_list_fetch(LIBSSH2_PUBLICKEY *pkey, unsigned long *num_keys, libssh2_publickey_list **pkey_list)
{
LIBSSH2_CHANNEL *channel = pkey->channel;
LIBSSH2_SESSION *session = channel->session;
libssh2_publickey_list *list = NULL;
unsigned char *s, buffer[12], *data = NULL;
unsigned long buffer_len = 12, keys = 0, max_keys = 0, data_len, i, response;
/* packet_len(4) +
list_len(4) +
"list"(4) */
s = buffer;
libssh2_htonu32(s, buffer_len - 4); s += 4;
libssh2_htonu32(s, sizeof("list") - 1); s += 4;
memcpy(s, "list", sizeof("list") - 1); s += sizeof("list") - 1;
#ifdef LIBSSH2_DEBUG_PUBLICKEY
_libssh2_debug(session, LIBSSH2_DBG_PUBLICKEY, "Sending publickey \"list\" packet");
#endif
if ((s - buffer) != libssh2_channel_write(channel, buffer, (s - buffer))) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send publickey list packet", 0);
return -1;
}
while (1) {
if (libssh2_publickey_packet_receive(pkey, &data, &data_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_TIMEOUT, "Timeout waiting for response from publickey subsystem", 0);
goto err_exit;
}
s = data;
if ((response = libssh2_publickey_response_id(&s, data_len)) < 0) {
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_PROTOCOL, "Invalid publickey subsystem response code", 0);
goto err_exit;
}
switch (response) {
case LIBSSH2_PUBLICKEY_RESPONSE_STATUS:
/* Error, or processing complete */
{
unsigned long status, descr_len, lang_len;
unsigned char *descr, *lang;
status = libssh2_ntohu32(s); s += 4;
descr_len = libssh2_ntohu32(s); s += 4;
descr = s; s += descr_len;
lang_len = libssh2_ntohu32(s); s += 4;
lang = s; s += lang_len;
if (s > data + data_len) {
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_PROTOCOL, "Malformed publickey subsystem packet", 0);
goto err_exit;
}
if (status == LIBSSH2_PUBLICKEY_SUCCESS) {
LIBSSH2_FREE(session, data);
*pkey_list = list;
*num_keys = keys;
return 0;
}
libssh2_publickey_status_error(pkey, session, status, descr, descr_len);
goto err_exit;
}
case LIBSSH2_PUBLICKEY_RESPONSE_PUBLICKEY:
/* What we want */
if (keys >= max_keys) {
/* Grow the key list if necessary */
max_keys += 8;
list = LIBSSH2_REALLOC(session, list, (max_keys + 1) * sizeof(libssh2_publickey_list));
if (!list) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for publickey list", 0);
goto err_exit;
}
}
if (pkey->version == 1) {
unsigned long comment_len;
comment_len = libssh2_ntohu32(s); s += 4;
if (comment_len) {
list[keys].num_attrs = 1;
list[keys].attrs = LIBSSH2_ALLOC(session, sizeof(libssh2_publickey_attribute));
if (!list[keys].attrs) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for publickey attributes", 0);
goto err_exit;
}
list[keys].attrs[0].name = "comment";
list[keys].attrs[0].name_len = sizeof("comment") - 1;
list[keys].attrs[0].value = s;
list[keys].attrs[0].value_len = comment_len;
list[keys].attrs[0].mandatory = 0;
s += comment_len;
} else {
list[keys].num_attrs = 0;
list[keys].attrs = NULL;
}
list[keys].name_len = libssh2_ntohu32(s); s += 4;
list[keys].name = s; s += list[keys].name_len;
list[keys].blob_len = libssh2_ntohu32(s); s += 4;
list[keys].blob = s; s += list[keys].blob_len;
} else {
/* Version == 2 */
list[keys].name_len = libssh2_ntohu32(s); s += 4;
list[keys].name = s; s += list[keys].name_len;
list[keys].blob_len = libssh2_ntohu32(s); s += 4;
list[keys].blob = s; s += list[keys].blob_len;
list[keys].num_attrs = libssh2_ntohu32(s); s += 4;
if (list[keys].num_attrs) {
list[keys].attrs = LIBSSH2_ALLOC(session, list[keys].num_attrs * sizeof(libssh2_publickey_attribute));
if (!list[keys].attrs) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for publickey attributes", 0);
goto err_exit;
}
for(i = 0; i < list[keys].num_attrs; i++) {
list[keys].attrs[i].name_len = libssh2_ntohu32(s); s += 4;
list[keys].attrs[i].name = s; s += list[keys].attrs[i].name_len;
list[keys].attrs[i].value_len = libssh2_ntohu32(s); s += 4;
list[keys].attrs[i].value = s; s += list[keys].attrs[i].value_len;
list[keys].attrs[i].mandatory = 0; /* actually an ignored value */
}
} else {
list[keys].attrs = NULL;
}
}
list[keys].packet = data; /* To be FREEd in libssh2_publickey_list_free() */
keys++;
list[keys].packet = NULL; /* Terminate the list */
data = NULL;
break;
default:
/* Unknown/Unexpected */
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_PROTOCOL, "Unexpected publickey subsystem response, ignoring", 0);
LIBSSH2_FREE(session, data);
}
}
/* Only reached via explicit goto */
err_exit:
if (data) {
LIBSSH2_FREE(session, data);
}
if (list) {
libssh2_publickey_list_free(pkey, list);
}
return -1;
}
/* {{{ libssh2_packet_queue_listener
* Queue a connection request for a listener
*/
inline int libssh2_packet_queue_listener(LIBSSH2_SESSION *session, unsigned char *data, unsigned long datalen)
{
/* Look for a matching listener */
unsigned char *s = data + (sizeof("forwarded-tcpip") - 1) + 5;
unsigned long packet_len = 17 + (sizeof("Forward not requested") - 1);
unsigned char *p, packet[17 + (sizeof("Forward not requested") - 1)];
/* packet_type(1) + channel(4) + reason(4) + descr(4) + lang(4) */
LIBSSH2_LISTENER *l = session->listeners;
char failure_code = 1; /* SSH_OPEN_ADMINISTRATIVELY_PROHIBITED */
unsigned long sender_channel, initial_window_size, packet_size;
unsigned char *host, *shost;
unsigned long port, sport, host_len, shost_len;
sender_channel = libssh2_ntohu32(s); s += 4;
initial_window_size = libssh2_ntohu32(s); s += 4;
packet_size = libssh2_ntohu32(s); s += 4;
host_len = libssh2_ntohu32(s); s += 4;
host = s; s += host_len;
port = libssh2_ntohu32(s); s += 4;
shost_len = libssh2_ntohu32(s); s += 4;
shost = s; s += shost_len;
sport = libssh2_ntohu32(s); s += 4;
#ifdef LIBSSH2_DEBUG_CONNECTION
_libssh2_debug(session, LIBSSH2_DBG_CONN, "Remote received connection from %s:%ld to %s:%ld", shost, sport, host, port);
#endif
while (l) {
if ((l->port == port) &&
(strlen(l->host) == host_len) &&
(memcmp(l->host, host, host_len) == 0)) {
/* This is our listener */
LIBSSH2_CHANNEL *channel, *last_queued = l->queue;
if (l->queue_maxsize &&
(l->queue_maxsize <= l->queue_size)) {
/* Queue is full */
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
#ifdef LIBSSH2_DEBUG_CONNECTION
_libssh2_debug(session, LIBSSH2_DBG_CONN, "Listener queue full, ignoring");
#endif
break;
}
channel = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_CHANNEL));
if (!channel) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate a channel for new connection", 0);
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
break;
}
memset(channel, 0, sizeof(LIBSSH2_CHANNEL));
channel->session = session;
channel->channel_type_len = sizeof("forwarded-tcpip") - 1;
channel->channel_type = LIBSSH2_ALLOC(session, channel->channel_type_len + 1);
if (!channel->channel_type) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate a channel for new connection", 0);
LIBSSH2_FREE(session, channel);
failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */
break;
}
memcpy(channel->channel_type, "forwarded-tcpip", channel->channel_type_len + 1);
channel->remote.id = sender_channel;
channel->remote.window_size_initial = LIBSSH2_CHANNEL_WINDOW_DEFAULT;
channel->remote.window_size = LIBSSH2_CHANNEL_WINDOW_DEFAULT;
channel->remote.packet_size = LIBSSH2_CHANNEL_PACKET_DEFAULT;
channel->local.id = libssh2_channel_nextid(session);
channel->local.window_size_initial = initial_window_size;
channel->local.window_size = initial_window_size;
channel->local.packet_size = packet_size;
#ifdef LIBSSH2_DEBUG_CONNECTION
_libssh2_debug(session, LIBSSH2_DBG_CONN, "Connection queued: channel %lu/%lu win %lu/%lu packet %lu/%lu",
channel->local.id, channel->remote.id,
channel->local.window_size, channel->remote.window_size,
channel->local.packet_size, channel->remote.packet_size);
#endif
p = packet;
*(p++) = SSH_MSG_CHANNEL_OPEN_CONFIRMATION;
libssh2_htonu32(p, channel->remote.id); p += 4;
libssh2_htonu32(p, channel->local.id); p += 4;
libssh2_htonu32(p, channel->remote.window_size_initial); p += 4;
libssh2_htonu32(p, channel->remote.packet_size); p += 4;
if (libssh2_packet_write(session, packet, 17)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send channel open confirmation", 0);
return -1;
}
/* Link the channel into the end of the queue list */
if (!last_queued) {
l->queue = channel;
return 0;
}
while (last_queued->next) last_queued = last_queued->next;
last_queued->next = channel;
channel->prev = last_queued;
l->queue_size++;
return 0;
}
l = l->next;
}
/* We're not listening to you */
{
p = packet;
*(p++) = SSH_MSG_CHANNEL_OPEN_FAILURE;
libssh2_htonu32(p, sender_channel); p += 4;
libssh2_htonu32(p, failure_code); p += 4;
libssh2_htonu32(p, sizeof("Forward not requested") - 1); p += 4;
memcpy(s, "Forward not requested", sizeof("Forward not requested") - 1); p += sizeof("Forward not requested") - 1;
libssh2_htonu32(p, 0);
if (libssh2_packet_write(session, packet, packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send open failure", 0);
return -1;
}
return 0;
}
}
/* {{{ proto libssh2_session_startup
* session: LIBSSH2_SESSION struct allocated and owned by the calling program
* Returns: 0 on success, or non-zero on failure
* Any memory allocated by libssh2 will use alloc/realloc/free
* callbacks in session
* socket *must* be populated with an opened and connected socket.
*/
LIBSSH2_API int
libssh2_session_startup(LIBSSH2_SESSION * session, int sock)
{
int rc;
if (session->startup_state == libssh2_NB_state_idle) {
_libssh2_debug(session, LIBSSH2_DBG_TRANS,
"session_startup for socket %d", sock);
/* FIXME: on some platforms (like win32) sockets are unsigned */
if (sock < 0) {
/* Did we forget something? */
libssh2_error(session, LIBSSH2_ERROR_SOCKET_NONE,
"Bad socket provided", 0);
return LIBSSH2_ERROR_SOCKET_NONE;
}
session->socket_fd = sock;
session->socket_block =
!_libssh2_get_socket_nonblocking(session->socket_fd);
if (session->socket_block) {
/*
* Since we can't be sure that we are in blocking or there
* was an error detecting the state, so set to blocking to
* be sure
*/
_libssh2_nonblock(session->socket_fd, 0);
}
session->startup_state = libssh2_NB_state_created;
}
/* TODO: Liveness check */
if (session->startup_state == libssh2_NB_state_created) {
rc = libssh2_banner_send(session);
if (rc == PACKET_EAGAIN) {
libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
"Would block sending banner to remote host", 0);
return LIBSSH2_ERROR_EAGAIN;
} else if (rc) {
/* Unable to send banner? */
libssh2_error(session, LIBSSH2_ERROR_BANNER_SEND,
"Error sending banner to remote host", 0);
return LIBSSH2_ERROR_BANNER_SEND;
}
session->startup_state = libssh2_NB_state_sent;
}
if (session->startup_state == libssh2_NB_state_sent) {
rc = libssh2_banner_receive(session);
if (rc == PACKET_EAGAIN) {
libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
"Would block waiting for banner", 0);
return LIBSSH2_ERROR_EAGAIN;
} else if (rc) {
/* Unable to receive banner from remote */
libssh2_error(session, LIBSSH2_ERROR_BANNER_NONE,
"Timeout waiting for banner", 0);
return LIBSSH2_ERROR_BANNER_NONE;
}
session->startup_state = libssh2_NB_state_sent1;
}
if (session->startup_state == libssh2_NB_state_sent1) {
rc = libssh2_kex_exchange(session, 0, &session->startup_key_state);
if (rc == PACKET_EAGAIN) {
libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
"Would block exchanging encryption keys", 0);
return LIBSSH2_ERROR_EAGAIN;
} else if (rc) {
libssh2_error(session, LIBSSH2_ERROR_KEX_FAILURE,
"Unable to exchange encryption keys", 0);
return LIBSSH2_ERROR_KEX_FAILURE;
}
session->startup_state = libssh2_NB_state_sent2;
}
if (session->startup_state == libssh2_NB_state_sent2) {
_libssh2_debug(session, LIBSSH2_DBG_TRANS,
"Requesting userauth service");
/* Request the userauth service */
session->startup_service[0] = SSH_MSG_SERVICE_REQUEST;
libssh2_htonu32(session->startup_service + 1,
sizeof("ssh-userauth") - 1);
memcpy(session->startup_service + 5, "ssh-userauth",
sizeof("ssh-userauth") - 1);
session->startup_state = libssh2_NB_state_sent3;
}
if (session->startup_state == libssh2_NB_state_sent3) {
rc = libssh2_packet_write(session, session->startup_service,
sizeof("ssh-userauth") + 5 - 1);
if (rc == PACKET_EAGAIN) {
libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
"Would block asking for ssh-userauth service", 0);
return LIBSSH2_ERROR_EAGAIN;
} else if (rc) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
"Unable to ask for ssh-userauth service", 0);
return LIBSSH2_ERROR_SOCKET_SEND;
}
session->startup_state = libssh2_NB_state_sent4;
}
if (session->startup_state == libssh2_NB_state_sent4) {
rc = libssh2_packet_require_ex(session, SSH_MSG_SERVICE_ACCEPT,
&session->startup_data,
&session->startup_data_len, 0, NULL, 0,
&session->startup_req_state);
if (rc == PACKET_EAGAIN) {
return LIBSSH2_ERROR_EAGAIN;
} else if (rc) {
return LIBSSH2_ERROR_SOCKET_DISCONNECT;
}
session->startup_service_length =
libssh2_ntohu32(session->startup_data + 1);
if ((session->startup_service_length != (sizeof("ssh-userauth") - 1))
|| strncmp("ssh-userauth", (char *) session->startup_data + 5,
session->startup_service_length)) {
LIBSSH2_FREE(session, session->startup_data);
session->startup_data = NULL;
libssh2_error(session, LIBSSH2_ERROR_PROTO,
"Invalid response received from server", 0);
return LIBSSH2_ERROR_PROTO;
}
LIBSSH2_FREE(session, session->startup_data);
session->startup_data = NULL;
session->startup_state = libssh2_NB_state_idle;
return 0;
}
/* just for safety return some error */
return LIBSSH2_ERROR_INVAL;
}
