/* GSSAPI/krb5 support for FTP - loosely based on old krb4.c * * Copyright (c) 1995, 1996, 1997, 1998, 1999, 2010 Kungliga Tekniska Högskolan * (Royal Institute of Technology, Stockholm, Sweden). * Copyright (c) 2004 - 2009 Daniel Stenberg * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * 3. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "setup.h" #ifndef CURL_DISABLE_FTP #ifdef HAVE_GSSAPI #ifdef HAVE_OLD_GSSMIT #define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name #endif #include <stdlib.h> #ifdef HAVE_NETDB_H #include <netdb.h> #endif #include <string.h> #ifdef HAVE_GSSGNU # include <gss.h> #elif defined HAVE_GSSMIT /* MIT style */ # include <gssapi/gssapi.h> # include <gssapi/gssapi_generic.h> # include <gssapi/gssapi_krb5.h> #else /* Heimdal-style */ # include <gssapi.h> #endif #include "urldata.h" #include "curl_base64.h" #include "ftp.h" #include "sendf.h" #include "krb4.h" #include "curl_memory.h" #define _MPRINTF_REPLACE /* use our functions only */ #include <curl/mprintf.h> /* The last #include file should be: */ #include "memdebug.h" #define LOCAL_ADDR (&conn->local_addr) #define REMOTE_ADDR conn->ip_addr->ai_addr static int krb5_check_prot(void *app_data, int level) { app_data = NULL; /* prevent compiler warning */ if(level == prot_confidential) return -1; return 0; } static int krb5_decode(void *app_data, void *buf, int len, int level, struct connectdata *conn) { gss_ctx_id_t *context = app_data; OM_uint32 maj, min; gss_buffer_desc enc, dec; /* shut gcc up */ level = 0; conn = NULL; enc.value = buf; enc.length = len; maj = gss_unseal(&min, *context, &enc, &dec, NULL, NULL); if(maj != GSS_S_COMPLETE) { if(len >= 4) strcpy(buf, "599 "); return -1; } memcpy(buf, dec.value, dec.length); len = dec.length; gss_release_buffer(&min, &dec); return len; } static int krb5_overhead(void *app_data, int level, int len) { /* no arguments are used, just init them to prevent compiler warnings */ app_data = NULL; level = 0; len = 0; return 0; } static int krb5_encode(void *app_data, const void *from, int length, int level, void **to, struct connectdata *conn) { gss_ctx_id_t *context = app_data; gss_buffer_desc dec, enc; OM_uint32 maj, min; int state; int len; /* shut gcc up */ conn = NULL; /* NOTE that the cast is safe, neither of the krb5, gnu gss and heimdal * libraries modify the input buffer in gss_seal() */ dec.value = (void*)from; dec.length = length; maj = gss_seal(&min, *context, level == prot_private, GSS_C_QOP_DEFAULT, &dec, &state, &enc); if(maj != GSS_S_COMPLETE) return -1; /* malloc a new buffer, in case gss_release_buffer doesn't work as expected */ *to = malloc(enc.length); if(!*to) return -1; memcpy(*to, enc.value, enc.length); len = enc.length; gss_release_buffer(&min, &enc); return len; } static int krb5_auth(void *app_data, struct connectdata *conn) { int ret; char *p; const char *host = conn->host.name; ssize_t nread; curl_socklen_t l = sizeof(conn->local_addr); struct SessionHandle *data = conn->data; CURLcode result; const char *service = "ftp", *srv_host = "host"; gss_buffer_desc gssbuf, _gssresp, *gssresp; OM_uint32 maj, min; gss_name_t gssname; gss_ctx_id_t *context = app_data; struct gss_channel_bindings_struct chan; if(getsockname(conn->sock[FIRSTSOCKET], (struct sockaddr *)LOCAL_ADDR, &l) < 0) perror("getsockname()"); chan.initiator_addrtype = GSS_C_AF_INET; chan.initiator_address.length = l - 4; chan.initiator_address.value = &((struct sockaddr_in *)LOCAL_ADDR)->sin_addr.s_addr; chan.acceptor_addrtype = GSS_C_AF_INET; chan.acceptor_address.length = l - 4; chan.acceptor_address.value = &((struct sockaddr_in *)REMOTE_ADDR)->sin_addr.s_addr; chan.application_data.length = 0; chan.application_data.value = NULL; /* this loop will execute twice (once for service, once for host) */ while(1) { /* this really shouldn't be repeated here, but can't help it */ if(service == srv_host) { result = Curl_ftpsendf(conn, "AUTH GSSAPI"); if(result) return -2; if(Curl_GetFTPResponse(&nread, conn, NULL)) return -1; if(data->state.buffer[0] != '3') return -1; } gssbuf.value = data->state.buffer; gssbuf.length = snprintf(gssbuf.value, BUFSIZE, "%s@%s", service, host); maj = gss_import_name(&min, &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &gssname); if(maj != GSS_S_COMPLETE) { gss_release_name(&min, &gssname); if(service == srv_host) { Curl_failf(data, "Error importing service name %s", gssbuf.value); return AUTH_ERROR; } service = srv_host; continue; } { gss_OID t; gss_display_name(&min, gssname, &gssbuf, &t); Curl_infof(data, "Trying against %s\n", gssbuf.value); gss_release_buffer(&min, &gssbuf); } gssresp = GSS_C_NO_BUFFER; *context = GSS_C_NO_CONTEXT; do { ret = AUTH_OK; maj = gss_init_sec_context(&min, GSS_C_NO_CREDENTIAL, context, gssname, GSS_C_NO_OID, GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG, 0, &chan, gssresp, NULL, &gssbuf, NULL, NULL); if(gssresp) { free(_gssresp.value); gssresp = NULL; } if(maj != GSS_S_COMPLETE && maj != GSS_S_CONTINUE_NEEDED) { Curl_infof(data, "Error creating security context"); ret = AUTH_ERROR; break; } if(gssbuf.length != 0) { if(Curl_base64_encode(data, (char *)gssbuf.value, gssbuf.length, &p) < 1) { Curl_infof(data, "Out of memory base64-encoding"); ret = AUTH_CONTINUE; break; } result = Curl_ftpsendf(conn, "ADAT %s", p); free(p); if(result) { ret = -2; break; } if(Curl_GetFTPResponse(&nread, conn, NULL)) { ret = -1; break; } if(data->state.buffer[0] != '2' && data->state.buffer[0] != '3'){ Curl_infof(data, "Server didn't accept auth data\n"); ret = AUTH_ERROR; break; } p = data->state.buffer + 4; p = strstr(p, "ADAT="); if(p) { _gssresp.length = Curl_base64_decode(p + 5, (unsigned char **) &_gssresp.value); if(_gssresp.length < 1) { Curl_failf(data, "Out of memory base64-encoding"); ret = AUTH_CONTINUE; break; } } gssresp = &_gssresp; } } while(maj == GSS_S_CONTINUE_NEEDED); gss_release_name(&min, &gssname); if(gssresp) free(_gssresp.value); if(ret == AUTH_OK || service == srv_host) return ret; service = srv_host; } } struct Curl_sec_client_mech Curl_krb5_client_mech = { "GSSAPI", sizeof(gss_ctx_id_t), NULL, /* init */ krb5_auth, NULL, /* end */ krb5_check_prot, krb5_overhead, krb5_encode, krb5_decode }; #endif /* HAVE_GSSAPI */ #endif /* CURL_DISABLE_FTP */