OSX/libsecurity_apple_csp/lib/pbkdf2.c

   1 /*
   2  * Copyright (c) 2000-2001,2011,2013-2014 Apple 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) 1999,2011,2013-2014 Apple Inc. All Rights Reserved.
  23 */
  24 #include "pbkdf2.h"
  25 #include <ConditionalMacros.h>
  26 #include <string.h>
  27 /* Will write hLen bytes into dataPtr according to PKCS #5 2.0 spec.
  28    See: http://www.rsa.com/rsalabs/pubs/PKCS/html/pkcs-5.html for details.
  29    tempBuffer is a pointer to at least MAX (hLen, saltLen + 4) + hLen bytes. */
  30 static void
  31 F (PRF prf, uint32 hLen,
  32    const void *passwordPtr, uint32 passwordLen,
  33    const void *saltPtr, uint32 saltLen,
  34    uint32 iterationCount,
  35    uint32 blockNumber,
  36    void *dataPtr,
  37    void *tempBuffer)
  38 {
  39         uint8 *inBlock, *outBlock, *resultBlockPtr;
  40         uint32 iteration;
  41         outBlock = (uint8*)tempBuffer;
  42         inBlock = outBlock + hLen;
  43         /* Set up inBlock to contain Salt || INT (blockNumber). */
  44         memcpy (inBlock, saltPtr, saltLen);
  45
  46         inBlock[saltLen + 0] = (uint8)(blockNumber >> 24);
  47         inBlock[saltLen + 1] = (uint8)(blockNumber >> 16);
  48         inBlock[saltLen + 2] = (uint8)(blockNumber >> 8);
  49         inBlock[saltLen + 3] = (uint8)(blockNumber);
  50
  51         /* Caculate U1 (result goes to outBlock) and copy it to resultBlockPtr. */
  52         resultBlockPtr = (uint8*)dataPtr;
  53         prf (passwordPtr, passwordLen, inBlock, saltLen + 4, outBlock);
  54         memcpy (resultBlockPtr, outBlock, hLen);
  55         /* Calculate U2 though UiterationCount. */
  56         for (iteration = 2; iteration <= iterationCount; iteration++)
  57         {
  58                 uint8 *tempBlock;
  59                 uint32 byte;
  60                 /* Swap inBlock and outBlock pointers. */
  61                 tempBlock = inBlock;
  62                 inBlock = outBlock;
  63                 outBlock = tempBlock;
  64                 /* Now inBlock conatins Uiteration-1.  Calclulate Uiteration into outBlock. */
  65                 prf (passwordPtr, passwordLen, inBlock, hLen, outBlock);
  66                 /* Xor data in dataPtr (U1 \xor U2 \xor ... \xor Uiteration-1) with
  67                    outBlock (Uiteration). */
  68                 for (byte = 0; byte < hLen; byte++)
  69                         resultBlockPtr[byte] ^= outBlock[byte];
  70         }
  71 }
  72 void pbkdf2 (PRF prf, uint32 hLen,
  73                          const void *passwordPtr, uint32 passwordLen,
  74                          const void *saltPtr, uint32 saltLen,
  75                          uint32 iterationCount,
  76                          void *dkPtr, uint32 dkLen,
  77                          void *tempBuffer)
  78 {
  79         uint32 completeBlocks = dkLen / hLen;
  80         uint32 partialBlockSize = dkLen % hLen;
  81         uint32 blockNumber;
  82         uint8 *dataPtr = (uint8*)dkPtr;
  83         uint8 *blkBuffer = (uint8*)tempBuffer;
  84         /* First calculate all the complete hLen sized blocks required. */
  85         for (blockNumber = 1; blockNumber <= completeBlocks; blockNumber++)
  86         {
  87                 F (prf, hLen, passwordPtr, passwordLen, saltPtr, saltLen,
  88                    iterationCount, blockNumber, dataPtr, blkBuffer + hLen);
  89                 dataPtr += hLen;
  90         }
  91         /* Finally if the requested output size was not an even multiple of hLen, calculate
  92            the final block and copy the first partialBlockSize bytes of it to the output. */
  93         if (partialBlockSize > 0)
  94         {
  95                 F (prf, hLen, passwordPtr, passwordLen, saltPtr, saltLen,
  96                    iterationCount, blockNumber, blkBuffer, blkBuffer + hLen);
  97                 memcpy (dataPtr, blkBuffer, partialBlockSize);
  98         }
  99 }