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6b7f6369ece6fa217dfd39b95b040679d08faaef
curl/lib/http_ntlm.c
Daniel Stenberg 80a324386b Rene Bernhardt found and fixed a buffer overrun in the NTLM code, where 
libcurl always and unconditionally overwrote a stack-based array with 3 zero
bytes. I edited the fix to make it less likely to occur again (and added
a comment explaining the reason to the buffer size).
2004-12-07 23:09:41 +00:00

588 lines
17 KiB
C
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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2004, 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.
*
* $Id$
***************************************************************************/
#include "setup.h"
/* NTLM details:
http://davenport.sourceforge.net/ntlm.html
http://www.innovation.ch/java/ntlm.html
*/
#ifndef CURL_DISABLE_HTTP
#ifdef USE_SSLEAY
/* We need OpenSSL for the crypto lib to provide us with MD4 and DES */
/* -- WIN32 approved -- */
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>
#include "urldata.h"
#include "sendf.h"
#include "strequal.h"
#include "base64.h"
#include "http_ntlm.h"
#include "url.h"
#include "memory.h"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
#include <openssl/des.h>
#include <openssl/md4.h>
#include <openssl/ssl.h>
#if OPENSSL_VERSION_NUMBER < 0x00907001L
#define DES_key_schedule des_key_schedule
#define DES_cblock des_cblock
#define DES_set_odd_parity des_set_odd_parity
#define DES_set_key des_set_key
#define DES_ecb_encrypt des_ecb_encrypt
/* This is how things were done in the old days */
#define DESKEY(x) x
#define DESKEYARG(x) x
#else
/* Modern version */
#define DESKEYARG(x) *x
#define DESKEY(x) &x
#endif
/* The last #include file should be: */
#include "memdebug.h"
/* Define this to make the type-3 message include the NT response message */
#define USE_NTRESPONSES 1
/*
(*) = A "security buffer" is a triplet consisting of two shorts and one
long:
1. a 'short' containing the length of the buffer in bytes
2. a 'short' containing the allocated space for the buffer in bytes
3. a 'long' containing the offset to the start of the buffer from the
beginning of the NTLM message, in bytes.
*/
CURLntlm Curl_input_ntlm(struct connectdata *conn,
bool proxy, /* if proxy or not */
char *header) /* rest of the www-authenticate:
header */
{
/* point to the correct struct with this */
struct ntlmdata *ntlm;
ntlm = proxy?&conn->proxyntlm:&conn->ntlm;
/* skip initial whitespaces */
while(*header && isspace((int)*header))
header++;
if(checkprefix("NTLM", header)) {
unsigned char buffer[256];
header += strlen("NTLM");
while(*header && isspace((int)*header))
header++;
if(*header) {
/* We got a type-2 message here:
Index Description Content
0 NTLMSSP Signature Null-terminated ASCII "NTLMSSP"
(0x4e544c4d53535000)
8 NTLM Message Type long (0x02000000)
12 Target Name security buffer(*)
20 Flags long
24 Challenge 8 bytes
(32) Context (optional) 8 bytes (two consecutive longs)
(40) Target Information (optional) security buffer(*)
32 (48) start of data block
*/
size_t size = Curl_base64_decode(header, (char *)buffer);
ntlm->state = NTLMSTATE_TYPE2; /* we got a type-2 */
if(size >= 48)
/* the nonce of interest is index [24 .. 31], 8 bytes */
memcpy(ntlm->nonce, &buffer[24], 8);
/* at index decimal 20, there's a 32bit NTLM flag field */
}
else {
if(ntlm->state >= NTLMSTATE_TYPE1)
return CURLNTLM_BAD;
ntlm->state = NTLMSTATE_TYPE1; /* we should sent away a type-1 */
}
}
return CURLNTLM_FINE;
}
/*
* Turns a 56 bit key into the 64 bit, odd parity key and sets the key. The
* key schedule ks is also set.
*/
static void setup_des_key(unsigned char *key_56,
DES_key_schedule DESKEYARG(ks))
{
DES_cblock key;
key[0] = key_56[0];
key[1] = ((key_56[0] << 7) & 0xFF) | (key_56[1] >> 1);
key[2] = ((key_56[1] << 6) & 0xFF) | (key_56[2] >> 2);
key[3] = ((key_56[2] << 5) & 0xFF) | (key_56[3] >> 3);
key[4] = ((key_56[3] << 4) & 0xFF) | (key_56[4] >> 4);
key[5] = ((key_56[4] << 3) & 0xFF) | (key_56[5] >> 5);
key[6] = ((key_56[5] << 2) & 0xFF) | (key_56[6] >> 6);
key[7] = (key_56[6] << 1) & 0xFF;
DES_set_odd_parity(&key);
DES_set_key(&key, ks);
}
/*
* takes a 21 byte array and treats it as 3 56-bit DES keys. The
* 8 byte plaintext is encrypted with each key and the resulting 24
* bytes are stored in the results array.
*/
static void calc_resp(unsigned char *keys,
unsigned char *plaintext,
unsigned char *results)
{
DES_key_schedule ks;
setup_des_key(keys, DESKEY(ks));
DES_ecb_encrypt((DES_cblock*) plaintext, (DES_cblock*) results,
DESKEY(ks), DES_ENCRYPT);
setup_des_key(keys+7, DESKEY(ks));
DES_ecb_encrypt((DES_cblock*) plaintext, (DES_cblock*) (results+8),
DESKEY(ks), DES_ENCRYPT);
setup_des_key(keys+14, DESKEY(ks));
DES_ecb_encrypt((DES_cblock*) plaintext, (DES_cblock*) (results+16),
DESKEY(ks), DES_ENCRYPT);
}
/*
* Set up lanmanager and nt hashed passwords
*/
static void mkhash(char *password,
unsigned char *nonce, /* 8 bytes */
unsigned char *lmresp /* must fit 0x18 bytes */
#ifdef USE_NTRESPONSES
, unsigned char *ntresp /* must fit 0x18 bytes */
#endif
)
{
/* 21 bytes fits 3 7-bytes chunks, as we use 56 bit (7 bytes) as DES input,
and we add three different ones, see the calc_resp() function */
unsigned char lmbuffer[21];
#ifdef USE_NTRESPONSES
unsigned char ntbuffer[21];
#endif
unsigned char *pw;
static const unsigned char magic[] = {
0x4B, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25
};
unsigned int i;
size_t len = strlen(password);
/* make it fit at least 14 bytes */
pw = malloc(len<7?14:len*2);
if(!pw)
return; /* this will lead to a badly generated package */
if (len > 14)
len = 14;
for (i=0; i<len; i++)
pw[i] = toupper(password[i]);
for (; i<14; i++)
pw[i] = 0;
{
/* create LanManager hashed password */
DES_key_schedule ks;
setup_des_key(pw, DESKEY(ks));
DES_ecb_encrypt((DES_cblock *)magic, (DES_cblock *)lmbuffer,
DESKEY(ks), DES_ENCRYPT);
setup_des_key(pw+7, DESKEY(ks));
DES_ecb_encrypt((DES_cblock *)magic, (DES_cblock *)(lmbuffer+8),
DESKEY(ks), DES_ENCRYPT);
memset(lmbuffer+16, 0, sizeof(lmbuffer)-16);
}
/* create LM responses */
calc_resp(lmbuffer, nonce, lmresp);
#ifdef USE_NTRESPONSES
{
/* create NT hashed password */
MD4_CTX MD4;
len = strlen(password);
for (i=0; i<len; i++) {
pw[2*i] = password[i];
pw[2*i+1] = 0;
}
MD4_Init(&MD4);
MD4_Update(&MD4, pw, 2*len);
MD4_Final(ntbuffer, &MD4);
memset(ntbuffer+16, 0, sizeof(ntbuffer)-16);
}
calc_resp(ntbuffer, nonce, ntresp);
#endif
free(pw);
}
#define SHORTPAIR(x) ((x) & 0xff), ((x) >> 8)
#define LONGQUARTET(x) ((x) & 0xff), (((x) >> 8)&0xff), \
(((x) >>16)&0xff), ((x)>>24)
/* this is for creating ntlm header output */
CURLcode Curl_output_ntlm(struct connectdata *conn,
bool proxy)
{
const char *domain=""; /* empty */
const char *host=""; /* empty */
int domlen=(int)strlen(domain);
int hostlen = (int)strlen(host);
int hostoff; /* host name offset */
int domoff; /* domain name offset */
size_t size;
char *base64=NULL;
unsigned char ntlmbuf[256]; /* enough, unless the host/domain is very long */
/* point to the address of the pointer that holds the string to sent to the
server, which is for a plain host or for a HTTP proxy */
char **allocuserpwd;
/* point to the name and password for this */
char *userp;
char *passwdp;
/* point to the correct struct with this */
struct ntlmdata *ntlm;
struct auth *authp;
curlassert(conn);
curlassert(conn->data);
if(proxy) {
allocuserpwd = &conn->allocptr.proxyuserpwd;
userp = conn->proxyuser;
passwdp = conn->proxypasswd;
ntlm = &conn->proxyntlm;
authp = &conn->data->state.authproxy;
}
else {
allocuserpwd = &conn->allocptr.userpwd;
userp = conn->user;
passwdp = conn->passwd;
ntlm = &conn->ntlm;
authp = &conn->data->state.authhost;
}
authp->done = FALSE;
/* not set means empty */
if(!userp)
userp=(char *)"";
if(!passwdp)
passwdp=(char *)"";
switch(ntlm->state) {
case NTLMSTATE_TYPE1:
default: /* for the weird cases we (re)start here */
hostoff = 32;
domoff = hostoff + hostlen;
/* Create and send a type-1 message:
Index Description Content
0 NTLMSSP Signature Null-terminated ASCII "NTLMSSP"
(0x4e544c4d53535000)
8 NTLM Message Type long (0x01000000)
12 Flags long
16 Supplied Domain security buffer(*)
24 Supplied Workstation security buffer(*)
32 start of data block
*/
snprintf((char *)ntlmbuf, sizeof(ntlmbuf), "NTLMSSP%c"
"\x01%c%c%c" /* 32-bit type = 1 */
"%c%c%c%c" /* 32-bit NTLM flag field */
"%c%c" /* domain length */
"%c%c" /* domain allocated space */
"%c%c" /* domain name offset */
"%c%c" /* 2 zeroes */
"%c%c" /* host length */
"%c%c" /* host allocated space */
"%c%c" /* host name offset */
"%c%c" /* 2 zeroes */
"%s" /* host name */
"%s", /* domain string */
0, /* trailing zero */
0,0,0, /* part of type-1 long */
LONGQUARTET(
NTLMFLAG_NEGOTIATE_OEM| /* 2 */
NTLMFLAG_NEGOTIATE_NTLM_KEY /* 200 */
/* equals 0x0202 */
),
SHORTPAIR(domlen),
SHORTPAIR(domlen),
SHORTPAIR(domoff),
0,0,
SHORTPAIR(hostlen),
SHORTPAIR(hostlen),
SHORTPAIR(hostoff),
0,0,
host, domain);
/* initial packet length */
size = 32 + hostlen + domlen;
/* now keeper of the base64 encoded package size */
size = Curl_base64_encode((char *)ntlmbuf, size, &base64);
if(size >0 ) {
Curl_safefree(*allocuserpwd);
*allocuserpwd = aprintf("%sAuthorization: NTLM %s\r\n",
proxy?"Proxy-":"",
base64);
free(base64);
}
else
return CURLE_OUT_OF_MEMORY; /* FIX TODO */
break;
case NTLMSTATE_TYPE2:
/* We received the type-2 already, create a type-3 message:
Index Description Content
0 NTLMSSP Signature Null-terminated ASCII "NTLMSSP"
(0x4e544c4d53535000)
8 NTLM Message Type long (0x03000000)
12 LM/LMv2 Response security buffer(*)
20 NTLM/NTLMv2 Response security buffer(*)
28 Domain Name security buffer(*)
36 User Name security buffer(*)
44 Workstation Name security buffer(*)
(52) Session Key (optional) security buffer(*)
(60) Flags (optional) long
52 (64) start of data block
*/
{
int lmrespoff;
int ntrespoff;
int useroff;
unsigned char lmresp[0x18]; /* fixed-size */
#ifdef USE_NTRESPONSES
unsigned char ntresp[0x18]; /* fixed-size */
#endif
const char *user;
int userlen;
user = strchr(userp, '\\');
if(!user)
user = strchr(userp, '/');
if (user) {
domain = userp;
domlen = (int)(user - domain);
user++;
}
else
user = userp;
userlen = (int)strlen(user);
mkhash(passwdp, &ntlm->nonce[0], lmresp
#ifdef USE_NTRESPONSES
, ntresp
#endif
);
domoff = 64; /* always */
useroff = domoff + domlen;
hostoff = useroff + userlen;
lmrespoff = hostoff + hostlen;
ntrespoff = lmrespoff + 0x18;
/* Create the big type-3 message binary blob */
size = snprintf((char *)ntlmbuf, sizeof(ntlmbuf),
"NTLMSSP%c"
"\x03%c%c%c" /* type-3, 32 bits */
"%c%c%c%c" /* LanManager length + allocated space */
"%c%c" /* LanManager offset */
"%c%c" /* 2 zeroes */
"%c%c" /* NT-response length */
"%c%c" /* NT-response allocated space */
"%c%c" /* NT-response offset */
"%c%c" /* 2 zeroes */
"%c%c" /* domain length */
"%c%c" /* domain allocated space */
"%c%c" /* domain name offset */
"%c%c" /* 2 zeroes */
"%c%c" /* user length */
"%c%c" /* user allocated space */
"%c%c" /* user offset */
"%c%c" /* 2 zeroes */
"%c%c" /* host length */
"%c%c" /* host allocated space */
"%c%c" /* host offset */
"%c%c%c%c%c%c" /* 6 zeroes */
"\xff\xff" /* message length */
"%c%c" /* 2 zeroes */
"\x01\x82" /* flags */
"%c%c" /* 2 zeroes */
/* domain string */
/* user string */
/* host string */
/* LanManager response */
/* NT response */
,
0, /* zero termination */
0,0,0, /* type-3 long, the 24 upper bits */
SHORTPAIR(0x18), /* LanManager response length, twice */
SHORTPAIR(0x18),
SHORTPAIR(lmrespoff),
0x0, 0x0,
#ifdef USE_NTRESPONSES
SHORTPAIR(0x18), /* NT-response length, twice */
SHORTPAIR(0x18),
#else
0x0, 0x0,
0x0, 0x0,
#endif
SHORTPAIR(ntrespoff),
0x0, 0x0,
SHORTPAIR(domlen),
SHORTPAIR(domlen),
SHORTPAIR(domoff),
0x0, 0x0,
SHORTPAIR(userlen),
SHORTPAIR(userlen),
SHORTPAIR(useroff),
0x0, 0x0,
SHORTPAIR(hostlen),
SHORTPAIR(hostlen),
SHORTPAIR(hostoff),
0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0,
0x0, 0x0);
/* size is now 64 */
size=64;
ntlmbuf[62]=ntlmbuf[63]=0;
memcpy(&ntlmbuf[size], domain, domlen);
size += domlen;
memcpy(&ntlmbuf[size], user, userlen);
size += userlen;
/* we append the binary hashes to the end of the blob */
if(size < ((int)sizeof(ntlmbuf) - 0x18)) {
memcpy(&ntlmbuf[size], lmresp, 0x18);
size += 0x18;
}
#ifdef USE_NTRESPONSES
if(size < ((int)sizeof(ntlmbuf) - 0x18)) {
memcpy(&ntlmbuf[size], ntresp, 0x18);
size += 0x18;
}
#endif
ntlmbuf[56] = (unsigned char)(size & 0xff);
ntlmbuf[57] = (unsigned char)(size >> 8);
/* convert the binary blob into base64 */
size = Curl_base64_encode((char *)ntlmbuf, size, &base64);
if(size >0 ) {
Curl_safefree(*allocuserpwd);
*allocuserpwd = aprintf("%sAuthorization: NTLM %s\r\n",
proxy?"Proxy-":"",
base64);
free(base64);
}
else
return CURLE_OUT_OF_MEMORY; /* FIX TODO */
ntlm->state = NTLMSTATE_TYPE3; /* we sent a type-3 */
authp->done = TRUE;
}
break;
case NTLMSTATE_TYPE3:
/* connection is already authenticated,
* don't send a header in future requests */
if(*allocuserpwd) {
free(*allocuserpwd);
*allocuserpwd=NULL;
}
authp->done = TRUE;
break;
}
return CURLE_OK;
}
#endif /* USE_SSLEAY */
#endif /* !CURL_DISABLE_HTTP */
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