libsecurity_apple_csp/lib/pbkdf2.c

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 /*
  20         File:           pbkdf2.c
  21         Contains:       Apple Data Security Services PKCS #5 PBKDF2 function definition.
  22         Copyright:      (C) 1999 by Apple Computer, Inc., all rights reserved
  23         Written by:     Michael Brouwer <mb@apple.com>
  24 */
  25 #include "pbkdf2.h"
  26 #include <CoreServices/../Frameworks/CarbonCore.framework/Headers/ConditionalMacros.h>
  27 #include <string.h>
  28 /* Will write hLen bytes into dataPtr according to PKCS #5 2.0 spec.
  29    See: http://www.rsa.com/rsalabs/pubs/PKCS/html/pkcs-5.html for details.
  30    tempBuffer is a pointer to at least MAX (hLen, saltLen + 4) + hLen bytes. */
  31 static void
  32 F (PRF prf, uint32 hLen,
  33    const void *passwordPtr, uint32 passwordLen,
  34    const void *saltPtr, uint32 saltLen,
  35    uint32 iterationCount,
  36    uint32 blockNumber,
  37    void *dataPtr,
  38    void *tempBuffer)
  39 {
  40         uint8 *inBlock, *outBlock, *resultBlockPtr;
  41         uint32 iteration;
  42         outBlock = (uint8*)tempBuffer;
  43         inBlock = outBlock + hLen;
  44         /* Set up inBlock to contain Salt || INT (blockNumber). */
  45         memcpy (inBlock, saltPtr, saltLen);
  46
  47         inBlock[saltLen + 0] = (uint8)(blockNumber >> 24);
  48         inBlock[saltLen + 1] = (uint8)(blockNumber >> 16);
  49         inBlock[saltLen + 2] = (uint8)(blockNumber >> 8);
  50         inBlock[saltLen + 3] = (uint8)(blockNumber);
  51
  52         /* Caculate U1 (result goes to outBlock) and copy it to resultBlockPtr. */
  53         resultBlockPtr = (uint8*)dataPtr;
  54         prf (passwordPtr, passwordLen, inBlock, saltLen + 4, outBlock);
  55         memcpy (resultBlockPtr, outBlock, hLen);
  56         /* Calculate U2 though UiterationCount. */
  57         for (iteration = 2; iteration <= iterationCount; iteration++)
  58         {
  59                 uint8 *tempBlock;
  60                 uint32 byte;
  61                 /* Swap inBlock and outBlock pointers. */
  62                 tempBlock = inBlock;
  63                 inBlock = outBlock;
  64                 outBlock = tempBlock;
  65                 /* Now inBlock conatins Uiteration-1.  Calclulate Uiteration into outBlock. */
  66                 prf (passwordPtr, passwordLen, inBlock, hLen, outBlock);
  67                 /* Xor data in dataPtr (U1 \xor U2 \xor ... \xor Uiteration-1) with
  68                    outBlock (Uiteration). */
  69                 for (byte = 0; byte < hLen; byte++)
  70                         resultBlockPtr[byte] ^= outBlock[byte];
  71         }
  72 }
  73 void pbkdf2 (PRF prf, uint32 hLen,
  74                          const void *passwordPtr, uint32 passwordLen,
  75                          const void *saltPtr, uint32 saltLen,
  76                          uint32 iterationCount,
  77                          void *dkPtr, uint32 dkLen,
  78                          void *tempBuffer)
  79 {
  80         uint32 completeBlocks = dkLen / hLen;
  81         uint32 partialBlockSize = dkLen % hLen;
  82         uint32 blockNumber;
  83         uint8 *dataPtr = (uint8*)dkPtr;
  84         uint8 *blkBuffer = (uint8*)tempBuffer;
  85         /* First calculate all the complete hLen sized blocks required. */
  86         for (blockNumber = 1; blockNumber <= completeBlocks; blockNumber++)
  87         {
  88                 F (prf, hLen, passwordPtr, passwordLen, saltPtr, saltLen,
  89                    iterationCount, blockNumber, dataPtr, blkBuffer + hLen);
  90                 dataPtr += hLen;
  91         }
  92         /* Finally if the requested output size was not an even multiple of hLen, calculate
  93            the final block and copy the first partialBlockSize bytes of it to the output. */
  94         if (partialBlockSize > 0)
  95         {
  96                 F (prf, hLen, passwordPtr, passwordLen, saltPtr, saltLen,
  97                    iterationCount, blockNumber, blkBuffer, blkBuffer + hLen);
  98                 memcpy (dataPtr, blkBuffer, partialBlockSize);
  99         }
 100 }