CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
struct connectdata *conn)
{
struct SessionHandle *data = conn->data;
curl_socket_t sock = conn->sock[sockindex];
CURLcode code;
ssize_t actualread;
ssize_t written;
int result;
OM_uint32 gss_major_status, gss_minor_status, gss_status;
OM_uint32 gss_ret_flags;
int gss_conf_state, gss_enc;
gss_buffer_desc service = GSS_C_EMPTY_BUFFER;
gss_buffer_desc gss_send_token = GSS_C_EMPTY_BUFFER;
gss_buffer_desc gss_recv_token = GSS_C_EMPTY_BUFFER;
gss_buffer_desc gss_w_token = GSS_C_EMPTY_BUFFER;
gss_buffer_desc* gss_token = GSS_C_NO_BUFFER;
gss_name_t server = GSS_C_NO_NAME;
gss_name_t gss_client_name = GSS_C_NO_NAME;
unsigned short us_length;
char *user=NULL;
unsigned char socksreq[4]; /* room for GSS-API exchange header only */
char *serviceptr = data->set.str[STRING_SOCKS5_GSSAPI_SERVICE];
/* GSS-API request looks like
* +----+------+-----+----------------+
* |VER | MTYP | LEN | TOKEN |
* +----+------+----------------------+
* | 1 | 1 | 2 | up to 2^16 - 1 |
* +----+------+-----+----------------+
*/
/* prepare service name */
if(strchr(serviceptr, '/')) {
service.value = malloc(strlen(serviceptr));
if(!service.value)
return CURLE_OUT_OF_MEMORY;
service.length = strlen(serviceptr);
memcpy(service.value, serviceptr, service.length);
gss_major_status = gss_import_name(&gss_minor_status, &service,
(gss_OID) GSS_C_NULL_OID, &server);
}
else {
service.value = malloc(strlen(serviceptr) +strlen(conn->proxy.name)+2);
if(!service.value)
return CURLE_OUT_OF_MEMORY;
service.length = strlen(serviceptr) +strlen(conn->proxy.name)+1;
snprintf(service.value, service.length+1, "%s@%s",
serviceptr, conn->proxy.name);
gss_major_status = gss_import_name(&gss_minor_status, &service,
GSS_C_NT_HOSTBASED_SERVICE, &server);
}
gss_release_buffer(&gss_status, &service); /* clear allocated memory */
if(check_gss_err(data, gss_major_status,
gss_minor_status, "gss_import_name()")) {
failf(data, "Failed to create service name.");
gss_release_name(&gss_status, &server);
return CURLE_COULDNT_CONNECT;
}
/* As long as we need to keep sending some context info, and there's no */
/* errors, keep sending it... */
for(;;) {
gss_major_status = Curl_gss_init_sec_context(data,
&gss_minor_status,
&gss_context,
server,
&Curl_krb5_mech_oid,
NULL,
gss_token,
&gss_send_token,
true,
&gss_ret_flags);
if(gss_token != GSS_C_NO_BUFFER)
gss_release_buffer(&gss_status, &gss_recv_token);
if(check_gss_err(data, gss_major_status,
gss_minor_status, "gss_init_sec_context")) {
gss_release_name(&gss_status, &server);
gss_release_buffer(&gss_status, &gss_recv_token);
gss_release_buffer(&gss_status, &gss_send_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
failf(data, "Failed to initial GSS-API token.");
return CURLE_COULDNT_CONNECT;
}
if(gss_send_token.length != 0) {
socksreq[0] = 1; /* GSS-API subnegotiation version */
socksreq[1] = 1; /* authentication message type */
us_length = htons((short)gss_send_token.length);
memcpy(socksreq+2, &us_length, sizeof(short));
code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
if(code || (4 != written)) {
failf(data, "Failed to send GSS-API authentication request.");
gss_release_name(&gss_status, &server);
gss_release_buffer(&gss_status, &gss_recv_token);
gss_release_buffer(&gss_status, &gss_send_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
code = Curl_write_plain(conn, sock, (char *)gss_send_token.value,
gss_send_token.length, &written);
if(code || ((ssize_t)gss_send_token.length != written)) {
failf(data, "Failed to send GSS-API authentication token.");
gss_release_name(&gss_status, &server);
gss_release_buffer(&gss_status, &gss_recv_token);
gss_release_buffer(&gss_status, &gss_send_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
}
gss_release_buffer(&gss_status, &gss_send_token);
gss_release_buffer(&gss_status, &gss_recv_token);
if(gss_major_status != GSS_S_CONTINUE_NEEDED) break;
/* analyse response */
/* GSS-API response looks like
* +----+------+-----+----------------+
* |VER | MTYP | LEN | TOKEN |
* +----+------+----------------------+
* | 1 | 1 | 2 | up to 2^16 - 1 |
* +----+------+-----+----------------+
*/
result=Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread);
if(result || (actualread != 4)) {
failf(data, "Failed to receive GSS-API authentication response.");
gss_release_name(&gss_status, &server);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
/* ignore the first (VER) byte */
if(socksreq[1] == 255) { /* status / message type */
failf(data, "User was rejected by the SOCKS5 server (%d %d).",
socksreq[0], socksreq[1]);
gss_release_name(&gss_status, &server);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
if(socksreq[1] != 1) { /* status / messgae type */
failf(data, "Invalid GSS-API authentication response type (%d %d).",
socksreq[0], socksreq[1]);
gss_release_name(&gss_status, &server);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
memcpy(&us_length, socksreq+2, sizeof(short));
us_length = ntohs(us_length);
gss_recv_token.length=us_length;
gss_recv_token.value=malloc(us_length);
if(!gss_recv_token.value) {
failf(data,
"Could not allocate memory for GSS-API authentication "
"response token.");
gss_release_name(&gss_status, &server);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_OUT_OF_MEMORY;
}
result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value,
gss_recv_token.length, &actualread);
if(result || (actualread != us_length)) {
failf(data, "Failed to receive GSS-API authentication token.");
gss_release_name(&gss_status, &server);
gss_release_buffer(&gss_status, &gss_recv_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
gss_token = &gss_recv_token;
}
gss_release_name(&gss_status, &server);
/* Everything is good so far, user was authenticated! */
gss_major_status = gss_inquire_context (&gss_minor_status, gss_context,
&gss_client_name, NULL, NULL, NULL,
NULL, NULL, NULL);
if(check_gss_err(data, gss_major_status,
gss_minor_status, "gss_inquire_context")) {
gss_delete_sec_context(&gss_status, &gss_context, NULL);
gss_release_name(&gss_status, &gss_client_name);
failf(data, "Failed to determine user name.");
return CURLE_COULDNT_CONNECT;
}
gss_major_status = gss_display_name(&gss_minor_status, gss_client_name,
&gss_send_token, NULL);
if(check_gss_err(data, gss_major_status,
gss_minor_status, "gss_display_name")) {
gss_delete_sec_context(&gss_status, &gss_context, NULL);
gss_release_name(&gss_status, &gss_client_name);
gss_release_buffer(&gss_status, &gss_send_token);
failf(data, "Failed to determine user name.");
return CURLE_COULDNT_CONNECT;
}
user=malloc(gss_send_token.length+1);
if(!user) {
gss_delete_sec_context(&gss_status, &gss_context, NULL);
gss_release_name(&gss_status, &gss_client_name);
gss_release_buffer(&gss_status, &gss_send_token);
return CURLE_OUT_OF_MEMORY;
}
memcpy(user, gss_send_token.value, gss_send_token.length);
user[gss_send_token.length] = '\0';
gss_release_name(&gss_status, &gss_client_name);
gss_release_buffer(&gss_status, &gss_send_token);
infof(data, "SOCKS5 server authencticated user %s with GSS-API.\n",user);
free(user);
user=NULL;
/* Do encryption */
socksreq[0] = 1; /* GSS-API subnegotiation version */
socksreq[1] = 2; /* encryption message type */
gss_enc = 0; /* no data protection */
/* do confidentiality protection if supported */
if(gss_ret_flags & GSS_C_CONF_FLAG)
gss_enc = 2;
/* else do integrity protection */
else if(gss_ret_flags & GSS_C_INTEG_FLAG)
gss_enc = 1;
infof(data, "SOCKS5 server supports GSS-API %s data protection.\n",
(gss_enc==0)?"no":((gss_enc==1)?"integrity":"confidentiality"));
/* force for the moment to no data protection */
gss_enc = 0;
/*
* Sending the encryption type in clear seems wrong. It should be
* protected with gss_seal()/gss_wrap(). See RFC1961 extract below
* The NEC reference implementations on which this is based is
* therefore at fault
*
* +------+------+------+.......................+
* + ver | mtyp | len | token |
* +------+------+------+.......................+
* + 0x01 | 0x02 | 0x02 | up to 2^16 - 1 octets |
* +------+------+------+.......................+
*
* Where:
*
* - "ver" is the protocol version number, here 1 to represent the
* first version of the SOCKS/GSS-API protocol
*
* - "mtyp" is the message type, here 2 to represent a protection
* -level negotiation message
*
* - "len" is the length of the "token" field in octets
*
* - "token" is the GSS-API encapsulated protection level
*
* The token is produced by encapsulating an octet containing the
* required protection level using gss_seal()/gss_wrap() with conf_req
* set to false. The token is verified using gss_unseal()/
* gss_unwrap().
*
*/
if(data->set.socks5_gssapi_nec) {
us_length = htons((short)1);
memcpy(socksreq+2, &us_length, sizeof(short));
}
else {
gss_send_token.length = 1;
gss_send_token.value = malloc(1);
if(!gss_send_token.value) {
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_OUT_OF_MEMORY;
}
memcpy(gss_send_token.value, &gss_enc, 1);
gss_major_status = gss_wrap(&gss_minor_status, gss_context, 0,
GSS_C_QOP_DEFAULT, &gss_send_token,
&gss_conf_state, &gss_w_token);
if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_wrap")) {
gss_release_buffer(&gss_status, &gss_send_token);
gss_release_buffer(&gss_status, &gss_w_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
failf(data, "Failed to wrap GSS-API encryption value into token.");
return CURLE_COULDNT_CONNECT;
}
gss_release_buffer(&gss_status, &gss_send_token);
us_length = htons((short)gss_w_token.length);
memcpy(socksreq+2, &us_length, sizeof(short));
}
code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
if(code || (4 != written)) {
failf(data, "Failed to send GSS-API encryption request.");
gss_release_buffer(&gss_status, &gss_w_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
if(data->set.socks5_gssapi_nec) {
memcpy(socksreq, &gss_enc, 1);
code = Curl_write_plain(conn, sock, socksreq, 1, &written);
if(code || ( 1 != written)) {
failf(data, "Failed to send GSS-API encryption type.");
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
}
else {
code = Curl_write_plain(conn, sock, (char *)gss_w_token.value,
gss_w_token.length, &written);
if(code || ((ssize_t)gss_w_token.length != written)) {
failf(data, "Failed to send GSS-API encryption type.");
gss_release_buffer(&gss_status, &gss_w_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
gss_release_buffer(&gss_status, &gss_w_token);
}
result=Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread);
if(result || (actualread != 4)) {
failf(data, "Failed to receive GSS-API encryption response.");
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
/* ignore the first (VER) byte */
if(socksreq[1] == 255) { /* status / message type */
failf(data, "User was rejected by the SOCKS5 server (%d %d).",
socksreq[0], socksreq[1]);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
if(socksreq[1] != 2) { /* status / messgae type */
failf(data, "Invalid GSS-API encryption response type (%d %d).",
socksreq[0], socksreq[1]);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
memcpy(&us_length, socksreq+2, sizeof(short));
us_length = ntohs(us_length);
gss_recv_token.length= us_length;
gss_recv_token.value=malloc(gss_recv_token.length);
if(!gss_recv_token.value) {
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_OUT_OF_MEMORY;
}
result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value,
gss_recv_token.length, &actualread);
if(result || (actualread != us_length)) {
failf(data, "Failed to receive GSS-API encryptrion type.");
gss_release_buffer(&gss_status, &gss_recv_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
if(!data->set.socks5_gssapi_nec) {
gss_major_status = gss_unwrap(&gss_minor_status, gss_context,
&gss_recv_token, &gss_w_token,
0, GSS_C_QOP_DEFAULT);
if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_unwrap")) {
gss_release_buffer(&gss_status, &gss_recv_token);
gss_release_buffer(&gss_status, &gss_w_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
failf(data, "Failed to unwrap GSS-API encryption value into token.");
return CURLE_COULDNT_CONNECT;
}
gss_release_buffer(&gss_status, &gss_recv_token);
if(gss_w_token.length != 1) {
failf(data, "Invalid GSS-API encryption response length (%d).",
gss_w_token.length);
gss_release_buffer(&gss_status, &gss_w_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
memcpy(socksreq, gss_w_token.value, gss_w_token.length);
gss_release_buffer(&gss_status, &gss_w_token);
}
else {
if(gss_recv_token.length != 1) {
failf(data, "Invalid GSS-API encryption response length (%d).",
gss_recv_token.length);
gss_release_buffer(&gss_status, &gss_recv_token);
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_COULDNT_CONNECT;
}
memcpy(socksreq, gss_recv_token.value, gss_recv_token.length);
gss_release_buffer(&gss_status, &gss_recv_token);
}
infof(data, "SOCKS5 access with%s protection granted.\n",
(socksreq[0]==0)?"out GSS-API data":
((socksreq[0]==1)?" GSS-API integrity":" GSS-API confidentiality"));
conn->socks5_gssapi_enctype = socksreq[0];
if(socksreq[0] == 0)
gss_delete_sec_context(&gss_status, &gss_context, NULL);
return CURLE_OK;
}
/*
* This function logs in to a SOCKS5 proxy and sends the specifics to the final
* destination server.
*/
CURLcode Curl_SOCKS5(const char *proxy_name,
const char *proxy_password,
const char *hostname,
int remote_port,
int sockindex,
struct connectdata *conn)
{
/*
According to the RFC1928, section "6. Replies". This is what a SOCK5
replies:
+----+-----+-------+------+----------+----------+
|VER | REP | RSV | ATYP | BND.ADDR | BND.PORT |
+----+-----+-------+------+----------+----------+
| 1 | 1 | X'00' | 1 | Variable | 2 |
+----+-----+-------+------+----------+----------+
Where:
o VER protocol version: X'05'
o REP Reply field:
o X'00' succeeded
*/
unsigned char socksreq[600]; /* room for large user/pw (255 max each) */
ssize_t actualread;
ssize_t written;
int result;
CURLcode code;
curl_socket_t sock = conn->sock[sockindex];
struct SessionHandle *data = conn->data;
long timeout;
bool socks5_resolve_local = (bool)(data->set.proxytype == CURLPROXY_SOCKS5);
const size_t hostname_len = strlen(hostname);
ssize_t packetsize = 0;
/* RFC1928 chapter 5 specifies max 255 chars for domain name in packet */
if(!socks5_resolve_local && hostname_len > 255)
{
infof(conn->data,"SOCKS5: server resolving disabled for hostnames of "
"length > 255 [actual len=%zu]\n", hostname_len);
socks5_resolve_local = TRUE;
}
/* get timeout */
timeout = Curl_timeleft(conn, NULL, TRUE);
if(timeout < 0) {
/* time-out, bail out, go home */
failf(data, "Connection time-out");
return CURLE_OPERATION_TIMEDOUT;
}
curlx_nonblock(sock, TRUE);
/* wait until socket gets connected */
result = Curl_socket_ready(CURL_SOCKET_BAD, sock, (int)timeout);
if(-1 == result) {
failf(conn->data, "SOCKS5: no connection here");
return CURLE_COULDNT_CONNECT;
}
else if(0 == result) {
failf(conn->data, "SOCKS5: connection timeout");
return CURLE_OPERATION_TIMEDOUT;
}
if(result & CURL_CSELECT_ERR) {
failf(conn->data, "SOCKS5: error occured during connection");
return CURLE_COULDNT_CONNECT;
}
socksreq[0] = 5; /* version */
#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
socksreq[1] = (char)(proxy_name ? 3 : 2); /* number of methods (below) */
socksreq[2] = 0; /* no authentication */
socksreq[3] = 1; /* gssapi */
socksreq[4] = 2; /* username/password */
#else
socksreq[1] = (char)(proxy_name ? 2 : 1); /* number of methods (below) */
socksreq[2] = 0; /* no authentication */
socksreq[3] = 2; /* username/password */
#endif
curlx_nonblock(sock, FALSE);
code = Curl_write_plain(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]),
&written);
if((code != CURLE_OK) || (written != (2 + (int)socksreq[1]))) {
failf(data, "Unable to send initial SOCKS5 request.");
return CURLE_COULDNT_CONNECT;
}
curlx_nonblock(sock, TRUE);
result = Curl_socket_ready(sock, CURL_SOCKET_BAD, (int)timeout);
if(-1 == result) {
failf(conn->data, "SOCKS5 nothing to read");
return CURLE_COULDNT_CONNECT;
}
else if(0 == result) {
failf(conn->data, "SOCKS5 read timeout");
return CURLE_OPERATION_TIMEDOUT;
}
if(result & CURL_CSELECT_ERR) {
failf(conn->data, "SOCKS5 read error occured");
return CURLE_RECV_ERROR;
}
curlx_nonblock(sock, FALSE);
result=Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread,
timeout);
if((result != CURLE_OK) || (actualread != 2)) {
failf(data, "Unable to receive initial SOCKS5 response.");
return CURLE_COULDNT_CONNECT;
}
if(socksreq[0] != 5) {
failf(data, "Received invalid version in initial SOCKS5 response.");
return CURLE_COULDNT_CONNECT;
}
if(socksreq[1] == 0) {
/* Nothing to do, no authentication needed */
;
}
#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
else if(socksreq[1] == 1) {
code = Curl_SOCKS5_gssapi_negotiate(sockindex, conn);
if(code != CURLE_OK) {
failf(data, "Unable to negotiate SOCKS5 gssapi context.");
return CURLE_COULDNT_CONNECT;
}
}
#endif
else if(socksreq[1] == 2) {
/* Needs user name and password */
size_t userlen, pwlen;
int len;
if(proxy_name && proxy_password) {
userlen = strlen(proxy_name);
pwlen = strlen(proxy_password);
}
else {
userlen = 0;
pwlen = 0;
}
/* username/password request looks like
* +----+------+----------+------+----------+
* |VER | ULEN | UNAME | PLEN | PASSWD |
* +----+------+----------+------+----------+
* | 1 | 1 | 1 to 255 | 1 | 1 to 255 |
* +----+------+----------+------+----------+
*/
len = 0;
socksreq[len++] = 1; /* username/pw subnegotiation version */
socksreq[len++] = (unsigned char) userlen;
if(proxy_name && userlen)
memcpy(socksreq + len, proxy_name, userlen);
len += (int)userlen;
socksreq[len++] = (unsigned char) pwlen;
if(proxy_password && pwlen)
memcpy(socksreq + len, proxy_password, pwlen);
len += (int)pwlen;
code = Curl_write_plain(conn, sock, (char *)socksreq, len, &written);
if((code != CURLE_OK) || (len != written)) {
failf(data, "Failed to send SOCKS5 sub-negotiation request.");
return CURLE_COULDNT_CONNECT;
}
result=Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread,
timeout);
if((result != CURLE_OK) || (actualread != 2)) {
failf(data, "Unable to receive SOCKS5 sub-negotiation response.");
return CURLE_COULDNT_CONNECT;
}
/* ignore the first (VER) byte */
if(socksreq[1] != 0) { /* status */
failf(data, "User was rejected by the SOCKS5 server (%d %d).",
socksreq[0], socksreq[1]);
return CURLE_COULDNT_CONNECT;
}
/* Everything is good so far, user was authenticated! */
}
else {
/* error */
#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
if(socksreq[1] == 255) {
#else
if(socksreq[1] == 1) {
failf(data,
"SOCKS5 GSSAPI per-message authentication is not supported.");
return CURLE_COULDNT_CONNECT;
}
else if(socksreq[1] == 255) {
#endif
if(!proxy_name || !*proxy_name) {
failf(data,
"No authentication method was acceptable. (It is quite likely"
" that the SOCKS5 server wanted a username/password, since none"
" was supplied to the server on this connection.)");
}
else {
failf(data, "No authentication method was acceptable.");
}
return CURLE_COULDNT_CONNECT;
}
else {
failf(data,
"Undocumented SOCKS5 mode attempted to be used by server.");
return CURLE_COULDNT_CONNECT;
}
}
/* Authentication is complete, now specify destination to the proxy */
socksreq[0] = 5; /* version (SOCKS5) */
socksreq[1] = 1; /* connect */
socksreq[2] = 0; /* must be zero */
if(!socks5_resolve_local) {
packetsize = (ssize_t)(5 + hostname_len + 2);
socksreq[3] = 3; /* ATYP: domain name = 3 */
socksreq[4] = (char) hostname_len; /* address length */
memcpy(&socksreq[5], hostname, hostname_len); /* address bytes w/o NULL */
*((unsigned short*)&socksreq[hostname_len+5]) =
htons((unsigned short)remote_port);
}
else {
struct Curl_dns_entry *dns;
Curl_addrinfo *hp=NULL;
int rc = Curl_resolv(conn, hostname, remote_port, &dns);
packetsize = 10;
socksreq[3] = 1; /* IPv4 = 1 */
if(rc == CURLRESOLV_ERROR)
return CURLE_COULDNT_RESOLVE_HOST;
if(rc == CURLRESOLV_PENDING) {
/* this requires that we're in "wait for resolve" state */
code = Curl_wait_for_resolv(conn, &dns);
if(code != CURLE_OK)
return code;
}
/*
* We cannot use 'hostent' as a struct that Curl_resolv() returns. It
* returns a Curl_addrinfo pointer that may not always look the same.
*/
if(dns)
hp=dns->addr;
if(hp) {
char buf[64];
unsigned short ip[4];
Curl_printable_address(hp, buf, sizeof(buf));
if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
&ip[0], &ip[1], &ip[2], &ip[3])) {
socksreq[4] = (unsigned char)ip[0];
socksreq[5] = (unsigned char)ip[1];
socksreq[6] = (unsigned char)ip[2];
socksreq[7] = (unsigned char)ip[3];
}
else
hp = NULL; /* fail! */
Curl_resolv_unlock(data, dns); /* not used anymore from now on */
}
if(!hp) {
failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.",
hostname);
return CURLE_COULDNT_RESOLVE_HOST;
}
*((unsigned short*)&socksreq[8]) = htons((unsigned short)remote_port);
}
#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
if(conn->socks5_gssapi_enctype) {
failf(data, "SOCKS5 gssapi protection not yet implemented.");
} else
#endif
code = Curl_write_plain(conn, sock, (char *)socksreq, packetsize, &written);
if((code != CURLE_OK) || (written != packetsize)) {
failf(data, "Failed to send SOCKS5 connect request.");
return CURLE_COULDNT_CONNECT;
}
packetsize = 10; /* minimum packet size is 10 */
#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
if(conn->socks5_gssapi_enctype) {
failf(data, "SOCKS5 gssapi protection not yet implemented.");
} else
#endif
result = Curl_blockread_all(conn, sock, (char *)socksreq, packetsize,
&actualread, timeout);
if((result != CURLE_OK) || (actualread != packetsize)) {
failf(data, "Failed to receive SOCKS5 connect request ack.");
return CURLE_COULDNT_CONNECT;
}
if(socksreq[0] != 5) { /* version */
failf(data,
"SOCKS5 reply has wrong version, version should be 5.");
return CURLE_COULDNT_CONNECT;
}
if(socksreq[1] != 0) { /* Anything besides 0 is an error */
failf(data,
"Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
}
/* Fix: in general, returned BND.ADDR is variable length parameter by RFC
1928, so the reply packet should be read until the end to avoid errors at
subsequent protocol level.
+----+-----+-------+------+----------+----------+
|VER | REP | RSV | ATYP | BND.ADDR | BND.PORT |
+----+-----+-------+------+----------+----------+
| 1 | 1 | X'00' | 1 | Variable | 2 |
+----+-----+-------+------+----------+----------+
ATYP:
o IP v4 address: X'01', BND.ADDR = 4 byte
o domain name: X'03', BND.ADDR = [ 1 byte length, string ]
o IP v6 address: X'04', BND.ADDR = 16 byte
*/
/* Calculate real packet size */
if(socksreq[3] == 3) {
/* domain name */
int addrlen = (int) socksreq[4];
packetsize = 5 + addrlen + 2;
}
else if(socksreq[3] == 4) {
/* IPv6 */
packetsize = 4 + 16 + 2;
}
/* At this point we already read first 10 bytes */
#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
if(!conn->socks5_gssapi_enctype) {
/* decrypt_gssapi_blockread already read the whole packet */
#endif
if(packetsize > 10) {
packetsize -= 10;
result = Curl_blockread_all(conn, sock, (char *)&socksreq[10],
packetsize, &actualread, timeout);
if((result != CURLE_OK) || (actualread != packetsize)) {
failf(data, "Failed to receive SOCKS5 connect request ack.");
return CURLE_COULDNT_CONNECT;
}
}
#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
}
#endif
curlx_nonblock(sock, TRUE);
return CURLE_OK; /* Proxy was successful! */
}
/* This is the SSPI-using version of this function */
CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
struct connectdata *conn)
{
struct SessionHandle *data = conn->data;
curl_socket_t sock = conn->sock[sockindex];
CURLcode code;
ssize_t actualread;
ssize_t written;
int result;
long timeout;
/* Needs GSSAPI authentication */
SECURITY_STATUS sspi_major_status, sspi_minor_status=0;
unsigned long sspi_ret_flags=0;
int gss_enc;
SecBuffer sspi_send_token, sspi_recv_token, sspi_w_token[3];
SecBufferDesc input_desc, output_desc, wrap_desc;
SecPkgContext_Sizes sspi_sizes;
CredHandle cred_handle;
CtxtHandle sspi_context;
PCtxtHandle context_handle = NULL;
SecPkgCredentials_Names names;
TimeStamp expiry;
char *service_name=NULL;
u_short us_length;
ULONG qop;
unsigned char socksreq[4]; /* room for gssapi exchange header only */
char *service = data->set.str[STRING_SOCKS5_GSSAPI_SERVICE];
/* get timeout */
timeout = Curl_timeleft(conn, NULL, TRUE);
/* GSSAPI request looks like
* +----+------+-----+----------------+
* |VER | MTYP | LEN | TOKEN |
* +----+------+----------------------+
* | 1 | 1 | 2 | up to 2^16 - 1 |
* +----+------+-----+----------------+
*/
/* prepare service name */
if (strchr(service, '/')) {
service_name = malloc(strlen(service));
if(!service_name)
return CURLE_OUT_OF_MEMORY;
memcpy(service_name, service, strlen(service));
}
else {
service_name = malloc(strlen(service) + strlen(conn->proxy.name) + 2);
if(!service_name)
return CURLE_OUT_OF_MEMORY;
snprintf(service_name,strlen(service) +strlen(conn->proxy.name)+2,"%s/%s",
service,conn->proxy.name);
}
input_desc.cBuffers = 1;
input_desc.pBuffers = &sspi_recv_token;
input_desc.ulVersion = SECBUFFER_VERSION;
sspi_recv_token.BufferType = SECBUFFER_TOKEN;
sspi_recv_token.cbBuffer = 0;
sspi_recv_token.pvBuffer = NULL;
output_desc.cBuffers = 1;
output_desc.pBuffers = &sspi_send_token;
output_desc.ulVersion = SECBUFFER_VERSION;
sspi_send_token.BufferType = SECBUFFER_TOKEN;
sspi_send_token.cbBuffer = 0;
sspi_send_token.pvBuffer = NULL;
wrap_desc.cBuffers = 3;
wrap_desc.pBuffers = sspi_w_token;
wrap_desc.ulVersion = SECBUFFER_VERSION;
cred_handle.dwLower = 0;
cred_handle.dwUpper = 0;
sspi_major_status = s_pSecFn->AcquireCredentialsHandleA( NULL,
(char *)"Kerberos",
SECPKG_CRED_OUTBOUND,
NULL,
NULL,
NULL,
NULL,
&cred_handle,
&expiry);
if(check_sspi_err(data, sspi_major_status,sspi_minor_status,
"AcquireCredentialsHandleA") ) {
failf(data, "Failed to acquire credentials.");
free(service_name);
service_name=NULL;
s_pSecFn->FreeCredentialsHandle(&cred_handle);
return CURLE_COULDNT_CONNECT;
}
/* As long as we need to keep sending some context info, and there's no */
/* errors, keep sending it... */
for(;;) {
sspi_major_status = s_pSecFn->InitializeSecurityContextA(
&cred_handle,
context_handle,
service_name,
ISC_REQ_MUTUAL_AUTH |
ISC_REQ_ALLOCATE_MEMORY |
ISC_REQ_CONFIDENTIALITY |
ISC_REQ_REPLAY_DETECT,
0,
SECURITY_NATIVE_DREP,
&input_desc,
0,
&sspi_context,
&output_desc,
&sspi_ret_flags,
&expiry);
if(sspi_recv_token.pvBuffer) {
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
sspi_recv_token.pvBuffer = NULL;
sspi_recv_token.cbBuffer = 0;
}
if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
"InitializeSecurityContextA") ){
free(service_name);
service_name=NULL;
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
failf(data, "Failed to initialise security context.");
return CURLE_COULDNT_CONNECT;
}
if(sspi_send_token.cbBuffer != 0) {
socksreq[0] = 1; /* gssapi subnegotiation version */
socksreq[1] = 1; /* authentication message type */
us_length = htons((short)sspi_send_token.cbBuffer);
memcpy(socksreq+2, &us_length, sizeof(short));
code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
if((code != CURLE_OK) || (4 != written)) {
failf(data, "Failed to send SSPI authentication request.");
free(service_name);
service_name=NULL;
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
code = Curl_write_plain(conn, sock, (char *)sspi_send_token.pvBuffer,
sspi_send_token.cbBuffer, &written);
if((code != CURLE_OK) || (sspi_send_token.cbBuffer != (size_t)written)) {
failf(data, "Failed to send SSPI authentication token.");
free(service_name);
service_name=NULL;
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
}
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
sspi_send_token.pvBuffer = NULL;
sspi_send_token.cbBuffer = 0;
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
sspi_recv_token.pvBuffer = NULL;
sspi_recv_token.cbBuffer = 0;
if(sspi_major_status != SEC_I_CONTINUE_NEEDED) break;
/* analyse response */
/* GSSAPI response looks like
* +----+------+-----+----------------+
* |VER | MTYP | LEN | TOKEN |
* +----+------+----------------------+
* | 1 | 1 | 2 | up to 2^16 - 1 |
* +----+------+-----+----------------+
*/
result=Curl_blockread_all(conn, sock, (char *)socksreq, 4,
&actualread, timeout);
if(result != CURLE_OK || actualread != 4) {
failf(data, "Failed to receive SSPI authentication response.");
free(service_name);
service_name=NULL;
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
/* ignore the first (VER) byte */
if(socksreq[1] == 255) { /* status / message type */
failf(data, "User was rejected by the SOCKS5 server (%d %d).",
socksreq[0], socksreq[1]);
free(service_name);
service_name=NULL;
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
if(socksreq[1] != 1) { /* status / messgae type */
failf(data, "Invalid SSPI authentication response type (%d %d).",
socksreq[0], socksreq[1]);
free(service_name);
service_name=NULL;
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
memcpy(&us_length, socksreq+2, sizeof(short));
us_length = ntohs(us_length);
sspi_recv_token.cbBuffer = us_length;
sspi_recv_token.pvBuffer = malloc(us_length);
if(!sspi_recv_token.pvBuffer) {
free(service_name);
service_name=NULL;
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_OUT_OF_MEMORY;
}
result = Curl_blockread_all(conn, sock, (char *)sspi_recv_token.pvBuffer,
sspi_recv_token.cbBuffer,
&actualread, timeout);
if(result != CURLE_OK || actualread != us_length) {
failf(data, "Failed to receive SSPI authentication token.");
free(service_name);
service_name=NULL;
s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
context_handle = &sspi_context;
}
free(service_name);
service_name=NULL;
/* Everything is good so far, user was authenticated! */
sspi_major_status = s_pSecFn->QueryCredentialsAttributes( &cred_handle,
SECPKG_CRED_ATTR_NAMES,
&names);
s_pSecFn->FreeCredentialsHandle(&cred_handle);
if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
"QueryCredentialAttributes") ){
s_pSecFn->DeleteSecurityContext(&sspi_context);
s_pSecFn->FreeContextBuffer(names.sUserName);
failf(data, "Failed to determine user name.");
return CURLE_COULDNT_CONNECT;
}
infof(data, "SOCKS5 server authencticated user %s with gssapi.\n",
names.sUserName);
s_pSecFn->FreeContextBuffer(names.sUserName);
/* Do encryption */
socksreq[0] = 1; /* gssapi subnegotiation version */
socksreq[1] = 2; /* encryption message type */
gss_enc = 0; /* no data protection */
/* do confidentiality protection if supported */
if(sspi_ret_flags & ISC_REQ_CONFIDENTIALITY)
gss_enc = 2;
/* else do integrity protection */
else if(sspi_ret_flags & ISC_REQ_INTEGRITY)
gss_enc = 1;
infof(data, "SOCKS5 server supports gssapi %s data protection.\n",
(gss_enc==0)?"no":((gss_enc==1)?"integrity":"confidentiality") );
/* force to no data protection, avoid encryption/decryption for now */
gss_enc = 0;
/*
* Sending the encryption type in clear seems wrong. It should be
* protected with gss_seal()/gss_wrap(). See RFC1961 extract below
* The NEC reference implementations on which this is based is
* therefore at fault
*
* +------+------+------+.......................+
* + ver | mtyp | len | token |
* +------+------+------+.......................+
* + 0x01 | 0x02 | 0x02 | up to 2^16 - 1 octets |
* +------+------+------+.......................+
*
* Where:
*
* - "ver" is the protocol version number, here 1 to represent the
* first version of the SOCKS/GSS-API protocol
*
* - "mtyp" is the message type, here 2 to represent a protection
* -level negotiation message
*
* - "len" is the length of the "token" field in octets
*
* - "token" is the GSS-API encapsulated protection level
*
* The token is produced by encapsulating an octet containing the
* required protection level using gss_seal()/gss_wrap() with conf_req
* set to FALSE. The token is verified using gss_unseal()/
* gss_unwrap().
*
*/
if(data->set.socks5_gssapi_nec) {
us_length = htons((short)1);
memcpy(socksreq+2, &us_length, sizeof(short));
}
else {
sspi_major_status = s_pSecFn->QueryContextAttributesA( &sspi_context,
SECPKG_ATTR_SIZES,
&sspi_sizes);
if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
"QueryContextAttributesA")) {
s_pSecFn->DeleteSecurityContext(&sspi_context);
failf(data, "Failed to query security context attributes.");
return CURLE_COULDNT_CONNECT;
}
sspi_w_token[0].cbBuffer = sspi_sizes.cbSecurityTrailer;
sspi_w_token[0].BufferType = SECBUFFER_TOKEN;
sspi_w_token[0].pvBuffer = malloc(sspi_sizes.cbSecurityTrailer);
if(!sspi_w_token[0].pvBuffer) {
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_OUT_OF_MEMORY;
}
sspi_w_token[1].cbBuffer = 1;
sspi_w_token[1].pvBuffer = malloc(1);
if(!sspi_w_token[1].pvBuffer){
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_OUT_OF_MEMORY;
}
memcpy(sspi_w_token[1].pvBuffer,&gss_enc,1);
sspi_w_token[2].BufferType = SECBUFFER_PADDING;
sspi_w_token[2].cbBuffer = sspi_sizes.cbBlockSize;
sspi_w_token[2].pvBuffer = malloc(sspi_sizes.cbBlockSize);
if(!sspi_w_token[2].pvBuffer) {
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_OUT_OF_MEMORY;
}
sspi_major_status = s_pSecFn->EncryptMessage( &sspi_context,
KERB_WRAP_NO_ENCRYPT,
&wrap_desc,
0);
if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
"EncryptMessage") ) {
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[2].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
failf(data, "Failed to query security context attributes.");
return CURLE_COULDNT_CONNECT;
}
sspi_send_token.cbBuffer = sspi_w_token[0].cbBuffer
+ sspi_w_token[1].cbBuffer
+ sspi_w_token[2].cbBuffer;
sspi_send_token.pvBuffer = malloc(sspi_send_token.cbBuffer);
if(!sspi_send_token.pvBuffer) {
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[2].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_OUT_OF_MEMORY;
}
memcpy(sspi_send_token.pvBuffer, sspi_w_token[0].pvBuffer,
sspi_w_token[0].cbBuffer);
memcpy((PUCHAR) sspi_send_token.pvBuffer +(int)sspi_w_token[0].cbBuffer,
sspi_w_token[1].pvBuffer, sspi_w_token[1].cbBuffer);
memcpy((PUCHAR) sspi_send_token.pvBuffer
+sspi_w_token[0].cbBuffer
+sspi_w_token[1].cbBuffer,
sspi_w_token[2].pvBuffer, sspi_w_token[2].cbBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
sspi_w_token[0].pvBuffer = NULL;
sspi_w_token[0].cbBuffer = 0;
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
sspi_w_token[1].pvBuffer = NULL;
sspi_w_token[1].cbBuffer = 0;
s_pSecFn->FreeContextBuffer(sspi_w_token[2].pvBuffer);
sspi_w_token[2].pvBuffer = NULL;
sspi_w_token[2].cbBuffer = 0;
us_length = htons((short)sspi_send_token.cbBuffer);
memcpy(socksreq+2,&us_length,sizeof(short));
}
code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
if((code != CURLE_OK) || (4 != written)) {
failf(data, "Failed to send SSPI encryption request.");
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
if(data->set.socks5_gssapi_nec) {
memcpy(socksreq,&gss_enc,1);
code = Curl_write_plain(conn, sock, (char *)socksreq, 1, &written);
if((code != CURLE_OK) || (1 != written)) {
failf(data, "Failed to send SSPI encryption type.");
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
} else {
code = Curl_write_plain(conn, sock, (char *)sspi_send_token.pvBuffer,
sspi_send_token.cbBuffer, &written);
if((code != CURLE_OK) || (sspi_send_token.cbBuffer != (size_t)written)) {
failf(data, "Failed to send SSPI encryption type.");
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
}
result=Curl_blockread_all(conn, sock, (char *)socksreq, 4,
&actualread, timeout);
if(result != CURLE_OK || actualread != 4) {
failf(data, "Failed to receive SSPI encryption response.");
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
/* ignore the first (VER) byte */
if(socksreq[1] == 255) { /* status / message type */
failf(data, "User was rejected by the SOCKS5 server (%d %d).",
socksreq[0], socksreq[1]);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
if(socksreq[1] != 2) { /* status / message type */
failf(data, "Invalid SSPI encryption response type (%d %d).",
socksreq[0], socksreq[1]);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
memcpy(&us_length, socksreq+2, sizeof(short));
us_length = ntohs(us_length);
sspi_w_token[0].cbBuffer = us_length;
sspi_w_token[0].pvBuffer = malloc(us_length);
if(!sspi_w_token[0].pvBuffer) {
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_OUT_OF_MEMORY;
}
result=Curl_blockread_all(conn, sock, (char *)sspi_w_token[0].pvBuffer,
sspi_w_token[0].cbBuffer,
&actualread, timeout);
if(result != CURLE_OK || actualread != us_length) {
failf(data, "Failed to receive SSPI encryption type.");
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
if(!data->set.socks5_gssapi_nec) {
wrap_desc.cBuffers = 2;
sspi_w_token[0].BufferType = SECBUFFER_STREAM;
sspi_w_token[1].BufferType = SECBUFFER_DATA;
sspi_w_token[1].cbBuffer = 0;
sspi_w_token[1].pvBuffer = NULL;
sspi_major_status = s_pSecFn->DecryptMessage( &sspi_context,
&wrap_desc,
0,
&qop);
if(check_sspi_err(data,sspi_major_status,sspi_minor_status,
"DecryptMessage")) {
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
failf(data, "Failed to query security context attributes.");
return CURLE_COULDNT_CONNECT;
}
if(sspi_w_token[1].cbBuffer != 1) {
failf(data, "Invalid SSPI encryption response length (%d).",
sspi_w_token[1].cbBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
memcpy(socksreq,sspi_w_token[1].pvBuffer,sspi_w_token[1].cbBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
} else {
if(sspi_w_token[0].cbBuffer != 1) {
failf(data, "Invalid SSPI encryption response length (%d).",
sspi_w_token[0].cbBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
s_pSecFn->DeleteSecurityContext(&sspi_context);
return CURLE_COULDNT_CONNECT;
}
memcpy(socksreq,sspi_w_token[0].pvBuffer,sspi_w_token[0].cbBuffer);
s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
}
infof(data, "SOCKS5 access with%s protection granted.\n",
(socksreq[0]==0)?"out gssapi data":
((socksreq[0]==1)?" gssapi integrity":" gssapi confidentiality"));
/* For later use if encryption is required
conn->socks5_gssapi_enctype = socksreq[0];
if (socksreq[0] != 0)
conn->socks5_sspi_context = sspi_context;
else {
s_pSecFn->DeleteSecurityContext(&sspi_context);
conn->socks5_sspi_context = sspi_context;
}
*/
return CURLE_OK;
}
/*
* This function logs in to a SOCKS4 proxy and sends the specifics to the final
* destination server.
*
* Reference :
* http://socks.permeo.com/protocol/socks4.protocol
*
* Note :
* Set protocol4a=true for "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)"
* Nonsupport "Identification Protocol (RFC1413)"
*/
CURLcode Curl_SOCKS4(const char *proxy_name,
const char *hostname,
int remote_port,
int sockindex,
struct connectdata *conn,
bool protocol4a)
{
#define SOCKS4REQLEN 262
unsigned char socksreq[SOCKS4REQLEN]; /* room for SOCKS4 request incl. user
id */
int result;
CURLcode code;
curl_socket_t sock = conn->sock[sockindex];
long timeout;
struct SessionHandle *data = conn->data;
/* get timeout */
timeout = Curl_timeleft(conn, NULL, TRUE);
if(timeout < 0) {
/* time-out, bail out, go home */
failf(data, "Connection time-out");
return CURLE_OPERATION_TIMEDOUT;
}
curlx_nonblock(sock, FALSE);
/*
* Compose socks4 request
*
* Request format
*
* +----+----+----+----+----+----+----+----+----+----+....+----+
* | VN | CD | DSTPORT | DSTIP | USERID |NULL|
* +----+----+----+----+----+----+----+----+----+----+....+----+
* # of bytes: 1 1 2 4 variable 1
*/
socksreq[0] = 4; /* version (SOCKS4) */
socksreq[1] = 1; /* connect */
*((unsigned short*)&socksreq[2]) = htons((unsigned short)remote_port);
/* DNS resolve only for SOCKS4, not SOCKS4a */
if (!protocol4a) {
struct Curl_dns_entry *dns;
Curl_addrinfo *hp=NULL;
int rc;
rc = Curl_resolv(conn, hostname, remote_port, &dns);
if(rc == CURLRESOLV_ERROR)
return CURLE_COULDNT_RESOLVE_PROXY;
if(rc == CURLRESOLV_PENDING)
/* ignores the return code, but 'dns' remains NULL on failure */
(void)Curl_wait_for_resolv(conn, &dns);
/*
* We cannot use 'hostent' as a struct that Curl_resolv() returns. It
* returns a Curl_addrinfo pointer that may not always look the same.
*/
if(dns)
hp=dns->addr;
if(hp) {
char buf[64];
unsigned short ip[4];
Curl_printable_address(hp, buf, sizeof(buf));
if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
&ip[0], &ip[1], &ip[2], &ip[3])) {
/* Set DSTIP */
socksreq[4] = (unsigned char)ip[0];
socksreq[5] = (unsigned char)ip[1];
socksreq[6] = (unsigned char)ip[2];
socksreq[7] = (unsigned char)ip[3];
}
else
hp = NULL; /* fail! */
Curl_resolv_unlock(data, dns); /* not used anymore from now on */
}
if(!hp) {
failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.",
hostname);
return CURLE_COULDNT_RESOLVE_HOST;
}
}
/*
* This is currently not supporting "Identification Protocol (RFC1413)".
*/
socksreq[8] = 0; /* ensure empty userid is NUL-terminated */
if(proxy_name)
strlcat((char*)socksreq + 8, proxy_name, sizeof(socksreq) - 8);
/*
* Make connection
*/
{
ssize_t actualread;
ssize_t written;
ssize_t hostnamelen = 0;
int packetsize = 9 +
(int)strlen((char*)socksreq + 8); /* size including NUL */
/* If SOCKS4a, set special invalid IP address 0.0.0.x */
if (protocol4a) {
socksreq[4] = 0;
socksreq[5] = 0;
socksreq[6] = 0;
socksreq[7] = 1;
/* If still enough room in buffer, also append hostname */
hostnamelen = (ssize_t)strlen(hostname) + 1; /* length including NUL */
if (packetsize + hostnamelen <= SOCKS4REQLEN)
strcpy((char*)socksreq + packetsize, hostname);
else
hostnamelen = 0; /* Flag: hostname did not fit in buffer */
}
/* Send request */
code = Curl_write_plain(conn, sock, (char *)socksreq,
packetsize + hostnamelen,
&written);
if((code != CURLE_OK) || (written != packetsize + hostnamelen)) {
failf(data, "Failed to send SOCKS4 connect request.");
return CURLE_COULDNT_CONNECT;
}
if (protocol4a && hostnamelen == 0) {
/* SOCKS4a with very long hostname - send that name separately */
hostnamelen = (ssize_t)strlen(hostname) + 1;
code = Curl_write_plain(conn, sock, (char *)hostname, hostnamelen,
&written);
if((code != CURLE_OK) || (written != hostnamelen)) {
failf(data, "Failed to send SOCKS4 connect request.");
return CURLE_COULDNT_CONNECT;
}
}
packetsize = 8; /* receive data size */
/* Receive response */
result = Curl_blockread_all(conn, sock, (char *)socksreq, packetsize,
&actualread, timeout);
if((result != CURLE_OK) || (actualread != packetsize)) {
failf(data, "Failed to receive SOCKS4 connect request ack.");
return CURLE_COULDNT_CONNECT;
}
/*
* Response format
*
* +----+----+----+----+----+----+----+----+
* | VN | CD | DSTPORT | DSTIP |
* +----+----+----+----+----+----+----+----+
* # of bytes: 1 1 2 4
*
* VN is the version of the reply code and should be 0. CD is the result
* code with one of the following values:
*
* 90: request granted
* 91: request rejected or failed
* 92: request rejected because SOCKS server cannot connect to
* identd on the client
* 93: request rejected because the client program and identd
* report different user-ids
*/
/* wrong version ? */
if(socksreq[0] != 0) {
failf(data,
"SOCKS4 reply has wrong version, version should be 4.");
return CURLE_COULDNT_CONNECT;
}
/* Result */
switch(socksreq[1])
{
case 90:
if (protocol4a)
infof(data, "SOCKS4a request granted.\n");
else
infof(data, "SOCKS4 request granted.\n");
break;
case 91:
failf(data,
"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
", request rejected or failed.",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
case 92:
failf(data,
"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
", request rejected because SOCKS server cannot connect to "
"identd on the client.",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
case 93:
failf(data,
"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
", request rejected because the client program and identd "
"report different user-ids.",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
default:
failf(data,
"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
", Unknown.",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
}
}
curlx_nonblock(sock, TRUE);
return CURLE_OK; /* Proxy was successful! */
}