ntlm/ntlmBlobPriv.c

   1 /*
   2  * Copyright (c) 2000-2004,2006-2008,2010-2014 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 /*
  25  * ntlmBlobPriv.c - Private routines used by NtlmGenerator module.
  26  */
  27
  28 #include "ntlmBlobPriv.h"
  29 #include <Security/SecBase.h>
  30
  31 #include <sys/types.h>
  32 #include <sys/uio.h>
  33 #include <unistd.h>
  34 #include <sys/param.h>
  35 #include <stdlib.h>
  36 #include <stdint.h>
  37 #include <assert.h>
  38 #include <fcntl.h>
  39 #include <ctype.h>
  40 #include <strings.h>
  41 #include <CommonCrypto/CommonDigest.h>
  42 #include <CommonCrypto/CommonCryptor.h>
  43 #include <CommonCrypto/CommonHMAC.h>
  44 #include <CoreFoundation/CFDate.h>
  45 #include <Security/SecFramework.h>
  46 #include <Security/SecRandom.h>
  47 #include <utilities/SecCFWrappers.h>
  48
  49 #if             DEBUG_FIXED_CHALLENGE
  50 /* Fixed 64-bit timestamp for sourceforge test vectors */
  51 static unsigned char dbgStamp[] =
  52 {
  53         0x00, 0x90, 0xd3, 0x36, 0xb7, 0x34, 0xc3, 0x01
  54 };
  55 #endif  /* DEBUG_FIXED_CHALLENGE */
  56
  57 // MARK: -
  58 // MARK: Encode/Decode Routines
  59
  60 /* write a 64-bit word, little endian */
  61 void appendUint64(
  62         CFMutableDataRef        buf,
  63         uint64_t                        word)
  64 {
  65 #if 1
  66         unsigned char cb[8];
  67         OSWriteLittleInt64(cb, 0, word);
  68         CFDataAppendBytes(buf, cb, 8);
  69 #else
  70         /* This is an alternate implementation which may or may not be faster than
  71            the above. */
  72         CFIndex offset = CFDataGetLength(buf);
  73         UInt8 *bytes = CFDataGetMutableBytePtr(buf);
  74         CFDataIncreaseLength(buf, 8);
  75         OSWriteLittleInt64(bytes, offset, word);
  76 #endif
  77 }
  78
  79 /* write a 32-bit word, little endian */
  80 void appendUint32(
  81         CFMutableDataRef        buf,
  82         uint32_t                        word)
  83 {
  84 #if 1
  85         unsigned char cb[4];
  86         OSWriteLittleInt32(cb, 0, word);
  87         CFDataAppendBytes(buf, cb, 4);
  88 #else
  89         /* This is an alternate implementation which may or may not be faster than
  90            the above. */
  91         CFIndex offset = CFDataGetLength(buf);
  92         UInt8 *bytes = CFDataGetMutableBytePtr(buf);
  93         CFDataIncreaseLength(buf, 4);
  94         OSWriteLittleInt32(bytes, offset, word);
  95 #endif
  96 }
  97
  98 /* write a 16-bit word, little endian */
  99 void appendUint16(
 100         CFMutableDataRef        buf,
 101         uint16_t                        word)
 102 {
 103         unsigned char cb[2];
 104         OSWriteLittleInt16(cb, 0, word);
 105         CFDataAppendBytes(buf, cb, 2);
 106 }
 107
 108 /*
 109  * Write a security buffer, providing the index into the CFData at which
 110  * this security buffer's offset is located. Just before the actual data is written,
 111  * go back and update the offset with the start of that data using secBufOffset().
 112  */
 113 void appendSecBuf(
 114         CFMutableDataRef        buf,
 115         uint16_t                        len,
 116         CFIndex                         *offsetIndex)
 117 {
 118 #if 1
 119         unsigned char cb[8];
 120         OSWriteLittleInt16(cb, 0, len);           /* buffer length */
 121         OSWriteLittleInt16(cb, 2, len);           /* buffer allocated size */
 122         OSWriteLittleInt32(cb, 4, 0);             /* offset is empty for now */
 123         CFDataAppendBytes(buf, cb, 8);
 124         *offsetIndex = CFDataGetLength(buf) - 4;  /* offset will go here */
 125 #else
 126         appendUint16(buf, len);                                 /* buffer length */
 127         appendUint16(buf, len);                                 /* buffer allocated size */
 128         *offsetIndex = CFDataGetLength(buf);    /* offset will go here */
 129         appendUint32(buf, 0);                                   /* but it's empty for now */
 130 #endif
 131 }
 132
 133 /*
 134  * Update a security buffer's offset to be the current end of data in a CFData.
 135  */
 136 void secBufOffset(
 137         CFMutableDataRef        buf,
 138         CFIndex                         offsetIndex)            /* obtained from appendSecBuf() */
 139 {
 140         CFIndex currPos = CFDataGetLength(buf);
 141         unsigned char cb[4];
 142         OSWriteLittleInt32(cb, 0, (uint32_t)currPos);
 143         CFRange range = {offsetIndex, 4};
 144         CFDataReplaceBytes(buf, range, cb, 4);
 145 }
 146
 147 /*
 148  * Parse/validate a security buffer. Verifies that supplied offset/length don't go
 149  * past end of avaialble data. Returns ptr to actual data and its length. Returns
 150  * NTLM_ERR_PARSE_ERR on bogus values.
 151  */
 152 OSStatus ntlmParseSecBuffer(
 153         const unsigned char *cp,                        /* start of security buffer */
 154         const unsigned char *bufStart,          /* start of whole msg buffer */
 155         unsigned bufLen,                                        /* # of valid bytes starting at bufStart */
 156         const unsigned char **data,                     /* RETURNED, start of actual data */
 157         uint16_t *dataLen)                                      /* RETURNED, length of actual data */
 158 {
 159         assert(cp >= bufStart);
 160
 161         uint16_t secBufLen = OSReadLittleInt16(cp, 0);
 162         /* skip length we just parsed plus alloc size, which we don't use */
 163         cp += 4;
 164         uint32_t offset = OSReadLittleInt32(cp, 0);
 165         if((offset + secBufLen) > bufLen) {
 166                 dprintf("ntlmParseSecBuffer: buf overflow\n");
 167                 return NTLM_ERR_PARSE_ERR;
 168         }
 169         *data = bufStart + offset;
 170         *dataLen = secBufLen;
 171         return errSecSuccess;
 172 }
 173
 174 // MARK: -
 175 // MARK: CFString Converters
 176
 177 /*
 178  * Convert CFString to little-endian unicode.
 179  */
 180 OSStatus ntlmStringToLE(
 181         CFStringRef             pwd,
 182         unsigned char   **ucode,                // mallocd and RETURNED
 183         unsigned                *ucodeLen)              // RETURNED
 184 {
 185         CFIndex len = CFStringGetLength(pwd);
 186     if (len > NTLM_MAX_STRING_LEN)
 187         return errSecAllocate;
 188         unsigned char *data = (unsigned char *)malloc(len * 2);
 189     if (data == NULL)
 190         return errSecAllocate;
 191         unsigned char *cp = data;
 192
 193         CFIndex dex;
 194         for(dex=0; dex<len; dex++) {
 195                 UniChar uc = CFStringGetCharacterAtIndex(pwd, dex);
 196                 *cp++ = uc & 0xff;
 197                 *cp++ = uc >> 8;
 198         }
 199         *ucode = data;
 200         *ucodeLen = (unsigned)(len * 2);
 201
 202     return errSecSuccess;
 203 }
 204
 205 /*
 206  * Convert a CFStringRef into a mallocd array of chars suitable for the specified
 207  * encoding. This might return an error if the string can't be converted
 208  * appropriately.
 209  */
 210 OSStatus ntlmStringFlatten(
 211         CFStringRef str,
 212         bool unicode,
 213         unsigned char **flat,                   // mallocd and RETURNED
 214         unsigned *flatLen)                              // RETURNED
 215 {
 216         if(unicode) {
 217                 /* convert to little-endian unicode */
 218                 return ntlmStringToLE(str, flat, flatLen);
 219         }
 220         else {
 221                 /* convert to ASCII C string */
 222                 CFIndex strLen = CFStringGetLength(str);
 223         if (strLen > NTLM_MAX_STRING_LEN)
 224             return errSecAllocate;
 225
 226                 char *cStr = (char *)malloc(strLen + 1);
 227                 if(cStr == NULL) {
 228                         return errSecAllocate;
 229                 }
 230                 if(CFStringGetCString(str, cStr, strLen + 1, kCFStringEncodingASCII)) {
 231                         *flat = (unsigned char *)cStr;
 232                         *flatLen = (unsigned)strLen;
 233                         return errSecSuccess;
 234                 }
 235
 236                 /*
 237                  * Well that didn't work. Try UTF8 - I don't know how a MS would behave if
 238                  * this portion of auth (only used for the LM response) didn't work.
 239                  */
 240                 dprintf("ntlmStringFlatten: ASCII password conversion failed; trying UTF8\n");
 241                 free(cStr);
 242
 243         CFDataRef dataFromString = CFStringCreateExternalRepresentation(NULL, str, kCFStringEncodingUTF8, 0);
 244                 if(dataFromString) {
 245                         *flatLen = (unsigned)CFDataGetLength(dataFromString);
 246             *flat = malloc(*flatLen);
 247             if (*flat == NULL) {
 248                 CFRelease(dataFromString);
 249                 return errSecAllocate;
 250             }
 251             memcpy(*flat, CFDataGetBytePtr(dataFromString), *flatLen);
 252             CFReleaseNull(dataFromString);
 253                         return errSecSuccess;
 254                 }
 255                 dprintf("lmPasswordHash: UTF8 password conversion failed\n");
 256         CFReleaseNull(dataFromString);
 257                 return NTLM_ERR_PARSE_ERR;
 258         }
 259 }
 260
 261 // MARK: -
 262 // MARK: Machine Dependent Cruft
 263
 264 /* random number generator */
 265 void ntlmRand(
 266         unsigned                len,
 267         void                    *buf)                           /* allocated by caller, random data RETURNED */
 268 {
 269     int status;
 270     status=SecRandomCopyBytes(kSecRandomDefault, len, buf);
 271     (void)status; // Prevent warning
 272 }
 273
 274 /* Obtain host name in appropriate encoding */
 275 OSStatus ntlmHostName(
 276         bool unicode,
 277         unsigned char **flat,                   // mallocd and RETURNED
 278         unsigned *flatLen)                              // RETURNED
 279 {
 280         char hostname[] = "WORKSTATION";
 281         size_t len = strlen(hostname);
 282         if(unicode) {
 283                 /* quickie "little endian unicode" conversion */
 284                 *flat = (unsigned char *)malloc(len * 2);
 285                 unsigned char *cp = *flat;
 286                 size_t dex;
 287                 for(dex=0; dex<len; dex++) {
 288                         *cp++ = hostname[dex];
 289                         *cp++ = 0;
 290                 }
 291                 *flatLen = (unsigned)len * 2;
 292                 return errSecSuccess;
 293         }
 294         else {
 295                 *flat = (unsigned char *)malloc(len+1);
 296                 *flatLen = (unsigned)len;
 297                 memmove(*flat, hostname, len);
 298         flat[len] = NULL; // ensure null terminator
 299                 return errSecSuccess;
 300         }
 301 }
 302
 303 /*
 304  * Append 64-bit little-endiam timestamp to a CFData. Time is relative to
 305  * January 1 1601, in tenths of a microsecond.
 306  */
 307
 308 CFGiblisGetSingleton(CFAbsoluteTime, ntlmGetBasis, ntlmBasisAbsoluteTime, ^{
 309     *ntlmBasisAbsoluteTime = CFAbsoluteTimeForGregorianZuluDay(1601, 1, 1);
 310 });
 311
 312 void ntlmAppendTimestamp(
 313         CFMutableDataRef ntlmV2Blob)
 314 {
 315         #if DEBUG_FIXED_CHALLENGE
 316         /* Fixed 64-bit timestamp for sourceforge test vectors */
 317         CFDataAppendBytes(ntlmV2Blob, dbgStamp, 8);
 318         #else
 319
 320         CFAbsoluteTime nowTime   = CFAbsoluteTimeGetCurrent();
 321
 322         /* elapsed := time in seconds since basis */
 323         CFTimeInterval elapsed = nowTime - ntlmGetBasis();
 324         /* now in tenths of microseconds */
 325         elapsed *= 10000000.0;
 326
 327         appendUint64(ntlmV2Blob, (uint64_t)elapsed);
 328         #endif
 329 }
 330
 331 // MARK: -
 332 // MARK: Crypto
 333
 334 /* MD4 and MD5 hash */
 335 #define NTLM_DIGEST_LENGTH   16
 336 void md4Hash(
 337         const unsigned char *data,
 338         unsigned                        dataLen,
 339         unsigned char           *digest)                // caller-supplied, NTLM_DIGEST_LENGTH */
 340 {
 341         CC_MD4_CTX ctx;
 342         CC_MD4_Init(&ctx);
 343         CC_MD4_Update(&ctx, data, dataLen);
 344         CC_MD4_Final(digest, &ctx);
 345 }
 346
 347 void md5Hash(
 348         const unsigned char *data,
 349         unsigned                        dataLen,
 350         unsigned char           *digest)                // caller-supplied, NTLM_DIGEST_LENGTH */
 351 {
 352         CC_MD5_CTX ctx;
 353         CC_MD5_Init(&ctx);
 354         CC_MD5_Update(&ctx, data, dataLen);
 355         CC_MD5_Final(digest, &ctx);
 356 }
 357
 358 /*
 359  * Given 7 bytes, create 8-byte DES key. Our implementation ignores the
 360  * parity bit (lsb), which simplifies this somewhat.
 361  */
 362 void ntlmMakeDesKey(
 363         const unsigned char *inKey,                     // 7 bytes
 364         unsigned char *outKey)                          // 8 bytes
 365 {
 366         outKey[0] =   inKey[0] & 0xfe;
 367         outKey[1] = ((inKey[0] << 7) | (inKey[1] >> 1)) & 0xfe;
 368         outKey[2] = ((inKey[1] << 6) | (inKey[2] >> 2)) & 0xfe;
 369         outKey[3] = ((inKey[2] << 5) | (inKey[3] >> 3)) & 0xfe;
 370         outKey[4] = ((inKey[3] << 4) | (inKey[4] >> 4)) & 0xfe;
 371         outKey[5] = ((inKey[4] << 3) | (inKey[5] >> 5)) & 0xfe;
 372         outKey[6] = ((inKey[5] << 2) | (inKey[6] >> 6)) & 0xfe;
 373         outKey[7] =  (inKey[6] << 1) & 0xfe;
 374 }
 375
 376 /*
 377  * single block DES encrypt.
 378  * This would really benefit from a DES implementation in CommonCrypto.
 379  */
 380 OSStatus ntlmDesCrypt(
 381         const unsigned char *key,               // 8 bytes
 382         const unsigned char *inData,    // 8 bytes
 383         unsigned char *outData)   // 8 bytes
 384 {
 385     size_t data_moved;
 386     return CCCrypt(kCCEncrypt, kCCAlgorithmDES, 0, key, kCCKeySizeDES,
 387         NULL /*no iv, 1 block*/, inData, 1 * kCCBlockSizeDES, outData,
 388         1 * kCCBlockSizeDES, &data_moved);
 389 }
 390
 391 /*
 392  * HMAC/MD5.
 393  */
 394 OSStatus ntlmHmacMD5(
 395         const unsigned char *key,
 396         unsigned                        keyLen,
 397         const unsigned char *inData,
 398         unsigned                        inDataLen,
 399         unsigned char           *mac)           // caller provided, NTLM_DIGEST_LENGTH
 400 {
 401     CCHmacContext hmac_md5_context;
 402
 403     CCHmacInit(&hmac_md5_context, kCCHmacAlgMD5, key, keyLen);
 404     CCHmacUpdate(&hmac_md5_context, inData, inDataLen);
 405     CCHmacFinal(&hmac_md5_context, mac);
 406
 407     return errSecSuccess;
 408 }
 409
 410 // MARK: -
 411 // MARK: NTLM password and digest munging
 412
 413
 414 /*
 415  * Calculate NTLM password hash (MD4 on a unicode password).
 416  */
 417 OSStatus ntlmPasswordHash(
 418         CFStringRef             pwd,
 419         unsigned char   *digest)                // caller-supplied, NTLM_DIGEST_LENGTH
 420 {
 421     OSStatus res;
 422         unsigned char *data;
 423         unsigned len;
 424
 425         /* convert to little-endian unicode */
 426     res = ntlmStringToLE(pwd, &data, &len);
 427     if (res)
 428         return res;
 429         /* md4 hash of that */
 430         md4Hash(data, len, digest);
 431         free(data);
 432
 433     return 0;
 434 }
 435
 436 /*
 437  * NTLM response: DES encrypt the challenge (or session hash) with three
 438  * different keys derived from the password hash. Result is concatenation
 439  * of three DES encrypts.
 440  */
 441 #define ALL_KEYS_LENGTH (3 * DES_RAW_KEY_SIZE)
 442 OSStatus lmv2Response(
 443         const unsigned char *digest,            // NTLM_DIGEST_LENGTH bytes
 444         const unsigned char *ptext,                     // challenge or session hash
 445         unsigned char           *ntlmResp)              // caller-supplied NTLM_LM_RESPONSE_LEN
 446 {
 447         unsigned char allKeys[ALL_KEYS_LENGTH];
 448         unsigned char key1[DES_KEY_SIZE], key2[DES_KEY_SIZE], key3[DES_KEY_SIZE];
 449         OSStatus ortn;
 450
 451         memmove(allKeys, digest, NTLM_DIGEST_LENGTH);
 452         memset(allKeys + NTLM_DIGEST_LENGTH, 0, ALL_KEYS_LENGTH - NTLM_DIGEST_LENGTH);
 453         ntlmMakeDesKey(allKeys, key1);
 454         ntlmMakeDesKey(allKeys + DES_RAW_KEY_SIZE, key2);
 455         ntlmMakeDesKey(allKeys + (2 * DES_RAW_KEY_SIZE), key3);
 456         ortn = ntlmDesCrypt(key1, ptext, ntlmResp);
 457         if(ortn == errSecSuccess) {
 458                 ortn = ntlmDesCrypt(key2, ptext, ntlmResp + DES_BLOCK_SIZE);
 459         }
 460         if(ortn == errSecSuccess) {
 461                 ortn = ntlmDesCrypt(key3, ptext, ntlmResp + (2 * DES_BLOCK_SIZE));
 462         }
 463         return ortn;
 464 }
 465