diff options
Diffstat (limited to 'lib/socks_gssapi.c')
| -rw-r--r-- | lib/socks_gssapi.c | 534 |
1 files changed, 534 insertions, 0 deletions
diff --git a/lib/socks_gssapi.c b/lib/socks_gssapi.c new file mode 100644 index 0000000..0eaa74c --- /dev/null +++ b/lib/socks_gssapi.c @@ -0,0 +1,534 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 2009, 2011, Markus Moeller, <markus_moeller@compuserve.com> + * Copyright (C) 2012, Daniel Stenberg, <daniel@haxx.se>, et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at http://curl.haxx.se/docs/copyright.html. + * + * You may opt to use, copy, modify, merge, publish, distribute and/or sell + * copies of the Software, and permit persons to whom the Software is + * furnished to do so, under the terms of the COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ***************************************************************************/ + +#include "curl_setup.h" + +#ifndef CURL_DISABLE_PROXY + +#ifdef HAVE_GSSAPI +#ifdef HAVE_OLD_GSSMIT +#define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name +#define NCOMPAT 1 +#endif +#ifndef gss_nt_service_name +#define gss_nt_service_name GSS_C_NT_HOSTBASED_SERVICE +#endif + +#include "curl_gssapi.h" +#include "urldata.h" +#include "sendf.h" +#include "connect.h" +#include "timeval.h" +#include "socks.h" +#include "warnless.h" + +#define _MPRINTF_REPLACE /* use our functions only */ +#include <curl/mprintf.h> + +#include "curl_memory.h" +/* The last #include file should be: */ +#include "memdebug.h" + +static gss_ctx_id_t gss_context = GSS_C_NO_CONTEXT; + +/* + * Helper GSS-API error functions. + */ +static int check_gss_err(struct SessionHandle *data, + OM_uint32 major_status, + OM_uint32 minor_status, + const char* function) +{ + if(GSS_ERROR(major_status)) { + OM_uint32 maj_stat,min_stat; + OM_uint32 msg_ctx = 0; + gss_buffer_desc status_string; + char buf[1024]; + size_t len; + + len = 0; + msg_ctx = 0; + while(!msg_ctx) { + /* convert major status code (GSS-API error) to text */ + maj_stat = gss_display_status(&min_stat, major_status, + GSS_C_GSS_CODE, + GSS_C_NULL_OID, + &msg_ctx, &status_string); + if(maj_stat == GSS_S_COMPLETE) { + if(sizeof(buf) > len + status_string.length + 1) { + strcpy(buf+len, (char*) status_string.value); + len += status_string.length; + } + gss_release_buffer(&min_stat, &status_string); + break; + } + gss_release_buffer(&min_stat, &status_string); + } + if(sizeof(buf) > len + 3) { + strcpy(buf+len, ".\n"); + len += 2; + } + msg_ctx = 0; + while(!msg_ctx) { + /* convert minor status code (underlying routine error) to text */ + maj_stat = gss_display_status(&min_stat, minor_status, + GSS_C_MECH_CODE, + GSS_C_NULL_OID, + &msg_ctx, &status_string); + if(maj_stat == GSS_S_COMPLETE) { + if(sizeof(buf) > len + status_string.length) + strcpy(buf+len, (char*) status_string.value); + gss_release_buffer(&min_stat, &status_string); + break; + } + gss_release_buffer(&min_stat, &status_string); + } + failf(data, "GSS-API error: %s failed:\n%s", function, buf); + return(1); + } + + return(0); +} + +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_nt_service_name, &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, + &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 != CURLE_OK) || (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 != CURLE_OK) || ((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 != CURLE_OK || 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 != CURLE_OK || 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 != CURLE_OK) || (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 != CURLE_OK) || ( 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 != CURLE_OK) || ((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 != CURLE_OK || 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 != CURLE_OK || 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; +} +#endif + +#endif /* CURL_DISABLE_PROXY */ |