/*
* _libssh2_packet_ask
*
* Scan the brigade for a matching packet type, optionally poll the socket for
* a packet first
*/
int
_libssh2_packet_ask(LIBSSH2_SESSION * session, unsigned char packet_type,
unsigned char **data, size_t *data_len,
int match_ofs, const unsigned char *match_buf,
size_t match_len)
{
LIBSSH2_PACKET *packet = _libssh2_list_first(&session->packets);
_libssh2_debug(session, LIBSSH2_TRACE_TRANS,
"Looking for packet of type: %d", (int) packet_type);
while (packet) {
if (packet->data[0] == packet_type
&& (packet->data_len >= (match_ofs + match_len))
&& (!match_buf ||
(memcmp(packet->data + match_ofs, match_buf,
match_len) == 0))) {
*data = packet->data;
*data_len = packet->data_len;
/* unlink struct from session->packets */
_libssh2_list_remove(&packet->node);
LIBSSH2_FREE(session, packet);
return 0;
}
packet = _libssh2_list_next(&packet->node);
}
return -1;
}
/*
* libssh2_knownhost_get()
*
* Traverse the internal list of known hosts. Pass NULL to 'prev' to get
* the first one.
*
* Returns:
* 0 if a fine host was stored in 'store'
* 1 if end of hosts
* [negative] on errors
*/
LIBSSH2_API int
libssh2_knownhost_get(LIBSSH2_KNOWNHOSTS *hosts,
struct libssh2_knownhost **ext,
struct libssh2_knownhost *oprev)
{
struct known_host *node;
if(oprev && oprev->node) {
/* we have a starting point */
struct known_host *prev = oprev->node;
/* get the next node in the list */
node = _libssh2_list_next(&prev->node);
}
else
node = _libssh2_list_first(&hosts->head);
if(!node)
/* no (more) node */
return 1;
*ext = knownhost_to_external(node);
return 0;
}
/*
* libssh2_knownhost_free
*
* Free an entire collection of known hosts.
*
*/
LIBSSH2_API void
libssh2_knownhost_free(LIBSSH2_KNOWNHOSTS *hosts)
{
struct known_host *node;
struct known_host *next;
for(node = _libssh2_list_first(&hosts->head); node; node = next) {
next = _libssh2_list_next(&node->node);
free_host(hosts->session, node);
}
LIBSSH2_FREE(hosts->session, hosts);
}
static void
agent_free_identities(LIBSSH2_AGENT *agent) {
struct agent_publickey *node;
struct agent_publickey *next;
for (node = _libssh2_list_first(&agent->head); node; node = next) {
next = _libssh2_list_next(&node->node);
LIBSSH2_FREE(agent->session, node->external.blob);
LIBSSH2_FREE(agent->session, node->external.comment);
LIBSSH2_FREE(agent->session, node);
}
_libssh2_list_init(&agent->head);
}
/*
* libssh2_knownhost_writefile()
*
* Write hosts+key pairs to the given file.
*/
LIBSSH2_API int
libssh2_knownhost_writefile(LIBSSH2_KNOWNHOSTS *hosts,
const char *filename, int type)
{
struct known_host *node;
FILE *file;
int rc = LIBSSH2_ERROR_NONE;
char buffer[2048];
/* we only support this single file type for now, bail out on all other
attempts */
if(type != LIBSSH2_KNOWNHOST_FILE_OPENSSH)
return _libssh2_error(hosts->session,
LIBSSH2_ERROR_METHOD_NOT_SUPPORTED,
"Unsupported type of known-host information "
"store");
file = fopen(filename, "w");
if(!file)
return _libssh2_error(hosts->session, LIBSSH2_ERROR_FILE,
"Failed to open file");
for(node = _libssh2_list_first(&hosts->head);
node;
node = _libssh2_list_next(&node->node)) {
size_t wrote = 0;
size_t nwrote;
rc = knownhost_writeline(hosts, node, buffer, sizeof(buffer), &wrote,
type);
if(rc)
break;
nwrote = fwrite(buffer, 1, wrote, file);
if(nwrote != wrote) {
/* failed to write the whole thing, bail out */
rc = _libssh2_error(hosts->session, LIBSSH2_ERROR_FILE,
"Write failed");
break;
}
}
fclose(file);
return rc;
}
/*
* libssh2_agent_get_identity()
*
* Traverse the internal list of public keys. Pass NULL to 'prev' to get
* the first one. Or pass a poiner to the previously returned one to get the
* next.
*
* Returns:
* 0 if a fine public key was stored in 'store'
* 1 if end of public keys
* [negative] on errors
*/
LIBSSH2_API int
libssh2_agent_get_identity(LIBSSH2_AGENT *agent,
struct libssh2_agent_publickey **ext,
struct libssh2_agent_publickey *oprev)
{
struct agent_publickey *node;
if (oprev && oprev->node) {
/* we have a starting point */
struct agent_publickey *prev = oprev->node;
/* get the next node in the list */
node = _libssh2_list_next(&prev->node);
}
else
node = _libssh2_list_first(&agent->head);
if (!node)
/* no (more) node */
return 1;
*ext = agent_publickey_to_external(node);
return 0;
}
/*
* libssh2_knownhost_check
*
* Check a host and its associated key against the collection of known hosts.
*
* The typemask is the type/format of the given host name and key
*
* plain - ascii "hostname.domain.tld"
* sha1 - NOT SUPPORTED AS INPUT
* custom - prehashed base64 encoded. Note that this cannot use any salts.
*
* Returns:
*
* LIBSSH2_KNOWNHOST_CHECK_FAILURE
* LIBSSH2_KNOWNHOST_CHECK_NOTFOUND
* LIBSSH2_KNOWNHOST_CHECK_MATCH
* LIBSSH2_KNOWNHOST_CHECK_MISMATCH
*/
LIBSSH2_API int
libssh2_knownhost_check(LIBSSH2_KNOWNHOSTS *hosts,
const char *host, const char *key, size_t keylen,
int typemask,
struct libssh2_knownhost **ext)
{
struct known_host *node = _libssh2_list_first(&hosts->head);
struct known_host *badkey = NULL;
int type = typemask & LIBSSH2_KNOWNHOST_TYPE_MASK;
char *keyalloc = NULL;
int rc = LIBSSH2_KNOWNHOST_CHECK_NOTFOUND;
if(type == LIBSSH2_KNOWNHOST_TYPE_SHA1)
/* we can't work with a sha1 as given input */
return LIBSSH2_KNOWNHOST_CHECK_MISMATCH;
if(!(typemask & LIBSSH2_KNOWNHOST_KEYENC_BASE64)) {
/* we got a raw key input, convert it to base64 for the checks below */
size_t nlen = _libssh2_base64_encode(hosts->session, key, keylen,
&keyalloc);
if(!nlen)
return LIBSSH2_KNOWNHOST_CHECK_FAILURE;
/* make the key point to this */
key = keyalloc;
keylen = nlen;
}
while (node) {
int match = 0;
switch(node->typemask & LIBSSH2_KNOWNHOST_TYPE_MASK) {
case LIBSSH2_KNOWNHOST_TYPE_PLAIN:
if(type == LIBSSH2_KNOWNHOST_TYPE_PLAIN)
match = !strcmp(host, node->name);
break;
case LIBSSH2_KNOWNHOST_TYPE_CUSTOM:
if(type == LIBSSH2_KNOWNHOST_TYPE_CUSTOM)
match = !strcmp(host, node->name);
break;
case LIBSSH2_KNOWNHOST_TYPE_SHA1:
if(type == LIBSSH2_KNOWNHOST_TYPE_PLAIN) {
/* when we have the sha1 version stored, we can use a plain
input to produce a hash to compare with the stored hash.
*/
libssh2_hmac_ctx ctx;
unsigned char hash[SHA_DIGEST_LENGTH];
if(SHA_DIGEST_LENGTH != node->name_len) {
/* the name hash length must be the sha1 size or
we can't match it */
break;
}
libssh2_hmac_sha1_init(&ctx, node->salt, node->salt_len);
libssh2_hmac_update(ctx, (unsigned char *)host, strlen(host));
libssh2_hmac_final(ctx, hash);
libssh2_hmac_cleanup(&ctx);
if(!memcmp(hash, node->name, SHA_DIGEST_LENGTH))
/* this is a node we're interested in */
match = 1;
}
break;
default: /* unsupported type */
break;
}
if(match) {
/* host name match, now compare the keys */
if(!strcmp(key, node->key)) {
/* they match! */
*ext = knownhost_to_external(node);
badkey = NULL;
rc = LIBSSH2_KNOWNHOST_CHECK_MATCH;
break;
}
else {
/* remember the first node that had a host match but a failed
key match since we continue our search from here */
if(!badkey)
badkey = node;
}
}
node= _libssh2_list_next(&node->node);
}
if(badkey) {
/* key mismatch */
*ext = knownhost_to_external(badkey);
rc = LIBSSH2_KNOWNHOST_CHECK_MISMATCH;
}
if(keyalloc)
LIBSSH2_FREE(hosts->session, keyalloc);
return rc;
}
/*
* knownhost_check
*
* Check a host and its associated key against the collection of known hosts.
*
* The typemask is the type/format of the given host name and key
*
* plain - ascii "hostname.domain.tld"
* sha1 - NOT SUPPORTED AS INPUT
* custom - prehashed base64 encoded. Note that this cannot use any salts.
*
* Returns:
*
* LIBSSH2_KNOWNHOST_CHECK_FAILURE
* LIBSSH2_KNOWNHOST_CHECK_NOTFOUND
* LIBSSH2_KNOWNHOST_CHECK_MATCH
* LIBSSH2_KNOWNHOST_CHECK_MISMATCH
*/
static int
knownhost_check(LIBSSH2_KNOWNHOSTS *hosts,
const char *hostp, int port,
const char *key, size_t keylen,
int typemask,
struct libssh2_knownhost **ext)
{
struct known_host *node;
struct known_host *badkey = NULL;
int type = typemask & LIBSSH2_KNOWNHOST_TYPE_MASK;
char *keyalloc = NULL;
int rc = LIBSSH2_KNOWNHOST_CHECK_NOTFOUND;
char hostbuff[270]; /* most host names can't be longer than like 256 */
const char *host;
int numcheck; /* number of host combos to check */
int match = 0;
if(type == LIBSSH2_KNOWNHOST_TYPE_SHA1)
/* we can't work with a sha1 as given input */
return LIBSSH2_KNOWNHOST_CHECK_MISMATCH;
/* if a port number is given, check for a '[host]:port' first before the
plain 'host' */
if(port >= 0) {
int len = snprintf(hostbuff, sizeof(hostbuff), "[%s]:%d", hostp, port);
if (len < 0 || len >= (int)sizeof(hostbuff)) {
_libssh2_error(hosts->session,
LIBSSH2_ERROR_BUFFER_TOO_SMALL,
"Known-host write buffer too small");
return LIBSSH2_KNOWNHOST_CHECK_FAILURE;
}
host = hostbuff;
numcheck = 2; /* check both combos, start with this */
}
else {
host = hostp;
numcheck = 1; /* only check this host version */
}
if(!(typemask & LIBSSH2_KNOWNHOST_KEYENC_BASE64)) {
/* we got a raw key input, convert it to base64 for the checks below */
size_t nlen = _libssh2_base64_encode(hosts->session, key, keylen,
&keyalloc);
if(!nlen) {
_libssh2_error(hosts->session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate memory for base64-encoded "
"key");
return LIBSSH2_KNOWNHOST_CHECK_FAILURE;
}
/* make the key point to this */
key = keyalloc;
}
do {
node = _libssh2_list_first(&hosts->head);
while (node) {
switch(node->typemask & LIBSSH2_KNOWNHOST_TYPE_MASK) {
case LIBSSH2_KNOWNHOST_TYPE_PLAIN:
if(type == LIBSSH2_KNOWNHOST_TYPE_PLAIN)
match = !strcmp(host, node->name);
break;
case LIBSSH2_KNOWNHOST_TYPE_CUSTOM:
if(type == LIBSSH2_KNOWNHOST_TYPE_CUSTOM)
match = !strcmp(host, node->name);
break;
case LIBSSH2_KNOWNHOST_TYPE_SHA1:
if(type == LIBSSH2_KNOWNHOST_TYPE_PLAIN) {
/* when we have the sha1 version stored, we can use a
plain input to produce a hash to compare with the
stored hash.
*/
libssh2_hmac_ctx ctx;
unsigned char hash[SHA_DIGEST_LENGTH];
if(SHA_DIGEST_LENGTH != node->name_len) {
/* the name hash length must be the sha1 size or
we can't match it */
break;
}
libssh2_hmac_sha1_init(&ctx, (unsigned char *)node->salt,
node->salt_len);
libssh2_hmac_update(ctx, (unsigned char *)host,
strlen(host));
libssh2_hmac_final(ctx, hash);
libssh2_hmac_cleanup(&ctx);
if(!memcmp(hash, node->name, SHA_DIGEST_LENGTH))
/* this is a node we're interested in */
match = 1;
}
break;
default: /* unsupported type */
break;
}
if(match) {
int host_key_type = typemask & LIBSSH2_KNOWNHOST_KEY_MASK;
int known_key_type =
node->typemask & LIBSSH2_KNOWNHOST_KEY_MASK;
/* match on key type as follows:
- never match on an unknown key type
- if key_type is set to zero, ignore it an match always
- otherwise match when both key types are equal
*/
if ( (host_key_type != LIBSSH2_KNOWNHOST_KEY_UNKNOWN ) &&
( (host_key_type == 0) ||
(host_key_type == known_key_type) ) ) {
/* host name and key type match, now compare the keys */
if(!strcmp(key, node->key)) {
/* they match! */
if (ext)
*ext = knownhost_to_external(node);
badkey = NULL;
rc = LIBSSH2_KNOWNHOST_CHECK_MATCH;
break;
}
else {
/* remember the first node that had a host match but a
failed key match since we continue our search from
here */
if(!badkey)
badkey = node;
}
}
match = 0; /* don't count this as a match anymore */
}
node= _libssh2_list_next(&node->node);
}
host = hostp;
} while(!match && --numcheck);
if(badkey) {
/* key mismatch */
if (ext)
*ext = knownhost_to_external(badkey);
rc = LIBSSH2_KNOWNHOST_CHECK_MISMATCH;
}
if(keyalloc)
LIBSSH2_FREE(hosts->session, keyalloc);
return rc;
}
/*
* libssh2_packet_queue_listener
*
* Queue a connection request for a listener
*/
static inline int
packet_queue_listener(LIBSSH2_SESSION * session, unsigned char *data,
unsigned long datalen,
packet_queue_listener_state_t *listen_state)
{
/*
* Look for a matching listener
*/
/* 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 *listn = _libssh2_list_first(&session->listeners);
char failure_code = SSH_OPEN_ADMINISTRATIVELY_PROHIBITED;
int rc;
(void) datalen;
if (listen_state->state == libssh2_NB_state_idle) {
unsigned char *s = data + (sizeof("forwarded-tcpip") - 1) + 5;
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);
_libssh2_debug(session, LIBSSH2_TRACE_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 (listn) {
if ((listn->port == (int) listen_state->port) &&
(strlen(listn->host) == listen_state->host_len) &&
(memcmp (listn->host, listen_state->host,
listen_state->host_len) == 0)) {
/* This is our listener */
LIBSSH2_CHANNEL *channel = NULL;
listen_state->channel = NULL;
if (listen_state->state == libssh2_NB_state_allocated) {
if (listn->queue_maxsize &&
(listn->queue_maxsize <= listn->queue_size)) {
/* Queue is full */
failure_code = SSH_OPEN_RESOURCE_SHORTAGE;
_libssh2_debug(session, LIBSSH2_TRACE_CONN,
"Listener queue full, ignoring");
listen_state->state = libssh2_NB_state_sent;
break;
}
channel = LIBSSH2_CALLOC(session, sizeof(LIBSSH2_CHANNEL));
if (!channel) {
_libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate a channel for "
"new connection");
failure_code = SSH_OPEN_RESOURCE_SHORTAGE;
listen_state->state = libssh2_NB_state_sent;
break;
}
listen_state->channel = 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");
LIBSSH2_FREE(session, channel);
failure_code = 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_TRACE_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_store_u32(&p, channel->remote.id);
_libssh2_store_u32(&p, channel->local.id);
_libssh2_store_u32(&p,
channel->remote.window_size_initial);
_libssh2_store_u32(&p, channel->remote.packet_size);
listen_state->state = libssh2_NB_state_created;
}
if (listen_state->state == libssh2_NB_state_created) {
rc = _libssh2_transport_send(session, listen_state->packet,
17, NULL, 0);
if (rc == LIBSSH2_ERROR_EAGAIN)
return rc;
else if (rc) {
listen_state->state = libssh2_NB_state_idle;
return _libssh2_error(session, rc,
"Unable to send channel "
"open confirmation");
}
/* Link the channel into the end of the queue list */
if (listen_state->channel) {
_libssh2_list_add(&listn->queue,
&listen_state->channel->node);
listn->queue_size++;
}
listen_state->state = libssh2_NB_state_idle;
return 0;
}
}
listn = _libssh2_list_next(&listn->node);
}
listen_state->state = libssh2_NB_state_sent;
}
/* We're not listening to you */
p = listen_state->packet;
*(p++) = SSH_MSG_CHANNEL_OPEN_FAILURE;
_libssh2_store_u32(&p, listen_state->sender_channel);
_libssh2_store_u32(&p, failure_code);
_libssh2_store_str(&p, FwdNotReq, sizeof(FwdNotReq) - 1);
_libssh2_htonu32(p, 0);
rc = _libssh2_transport_send(session, listen_state->packet,
packet_len, NULL, 0);
if (rc == LIBSSH2_ERROR_EAGAIN) {
return rc;
} else if (rc) {
listen_state->state = libssh2_NB_state_idle;
return _libssh2_error(session, rc, "Unable to send open failure");
}
listen_state->state = libssh2_NB_state_idle;
return 0;
}
