curl/lib/krb5.c

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/* GSSAPI/krb5 support for FTP - loosely based on old krb4.c
*
* Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska H<EFBFBD>gskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* 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_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_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 "base64.h"
#include "ftp.h"
#include "sendf.h"
#include "krb4.h"
#include "memory.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, 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;
dec.value = 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->dns_entry->addr->ai_canonname;
ssize_t nread;
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 */