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. */ 30static void 31F (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} 72void 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} 100