Security-55163.44.tar.gz

[apple/security.git] / sec / Security / pbkdf2.c

diff --git a/sec/Security/pbkdf2.c b/sec/Security/pbkdf2.c
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+/*
+ * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
+ *
+ * The contents of this file constitute Original Code as defined in and are
+ * subject to the Apple Public Source License Version 1.2 (the 'License').
+ * You may not use this file except in compliance with the License. Please obtain
+ * a copy of the License at http://www.apple.com/publicsource and read it before
+ * using this file.
+ *
+ * This Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
+ * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
+ * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+ * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
+ * specific language governing rights and limitations under the License.
+ */
+
+
+/*
+       File:           pbkdf2.c
+       Contains:       Apple Data Security Services PKCS #5 PBKDF2 function definition.
+       Copyright:      (C) 1999 by Apple Computer, Inc., all rights reserved
+       Written by:     Michael Brouwer <mb@apple.com>
+*/
+#include "pbkdf2.h"
+#include <string.h>
+/* Will write hLen bytes into dataPtr according to PKCS #5 2.0 spec.
+   See: http://www.rsa.com/rsalabs/node.asp?id=2127 for details.
+   tempBuffer is a pointer to at least MAX (hLen, saltLen + 4) + hLen bytes. */
+static void
+F (PRF prf, size_t hLen,
+   const void *passwordPtr, size_t passwordLen,
+   const void *saltPtr, size_t saltLen,
+   size_t iterationCount,
+   uint32_t blockNumber,
+   void *dataPtr,
+   void *tempBuffer)
+{
+       uint8_t *inBlock, *outBlock, *resultBlockPtr;
+       uint32_t iteration;
+       outBlock = (uint8_t*)tempBuffer;
+       inBlock = outBlock + hLen;
+       /* Set up inBlock to contain Salt || INT (blockNumber). */
+       memcpy (inBlock, saltPtr, saltLen);
+
+       inBlock[saltLen + 0] = (uint8_t)(blockNumber >> 24);
+       inBlock[saltLen + 1] = (uint8_t)(blockNumber >> 16);
+       inBlock[saltLen + 2] = (uint8_t)(blockNumber >> 8);
+       inBlock[saltLen + 3] = (uint8_t)(blockNumber);
+
+       /* Caculate U1 (result goes to outBlock) and copy it to resultBlockPtr. */
+       resultBlockPtr = (uint8_t*)dataPtr;
+       prf (passwordPtr, passwordLen, inBlock, saltLen + 4, outBlock);
+       memcpy (resultBlockPtr, outBlock, hLen);
+       /* Calculate U2 though UiterationCount. */
+       for (iteration = 2; iteration <= iterationCount; iteration++)
+       {
+               uint8_t *tempBlock;
+               uint32_t byte;
+               /* Swap inBlock and outBlock pointers. */
+               tempBlock = inBlock;
+               inBlock = outBlock;
+               outBlock = tempBlock;
+               /* Now inBlock conatins Uiteration-1.  Calculate Uiteration into outBlock. */
+               prf (passwordPtr, passwordLen, inBlock, hLen, outBlock);
+               /* Xor data in dataPtr (U1 \xor U2 \xor ... \xor Uiteration-1) with
+                  outBlock (Uiteration). */
+               for (byte = 0; byte < hLen; byte++)
+                       resultBlockPtr[byte] ^= outBlock[byte];
+       }
+}
+void pbkdf2 (PRF prf, size_t hLen,
+                        const void *passwordPtr, size_t passwordLen,
+                        const void *saltPtr, size_t saltLen,
+                        uint32_t iterationCount,
+                        void *dkPtr, size_t dkLen,
+                        void *tempBuffer)
+{
+       size_t completeBlocks = dkLen / hLen;
+       size_t partialBlockSize = dkLen % hLen;
+       uint32_t blockNumber;
+       uint8_t *dataPtr = (uint8_t*)dkPtr;
+       uint8_t *blkBuffer = (uint8_t*)tempBuffer;
+
+    /* This check make sure that the following loops ends, in case where dk_len is 64 bits, and very large.
+     This will cause the derived key to be the maximum size supported by pbkdf2 (4GB * size of the hash)
+     rather than the actual requested size.*/
+    completeBlocks=completeBlocks & UINT32_MAX;
+
+       /* First calculate all the complete hLen sized blocks required. */
+       for (blockNumber = 1; blockNumber <= completeBlocks; blockNumber++)
+       {
+               F (prf, hLen, passwordPtr, passwordLen, saltPtr, saltLen,
+                  iterationCount, blockNumber, dataPtr, blkBuffer + hLen);
+               dataPtr += hLen;
+       }
+       /* Finally if the requested output size was not an even multiple of hLen, calculate
+          the final block and copy the first partialBlockSize bytes of it to the output. */
+       if (partialBlockSize > 0)
+       {
+               F (prf, hLen, passwordPtr, passwordLen, saltPtr, saltLen,
+                  iterationCount, blockNumber, blkBuffer, blkBuffer + hLen);
+               memcpy (dataPtr, blkBuffer, partialBlockSize);
+       }
+}