OSX/sec/Security/SecPBKDF.c

   1 /*
   2  *  SecPBKDF.c
   3  *
   4  *  Copyright (c) 2010,2012 Apple Inc. All Rights Reserved.
   5  *
   6  */
   7
   8 #include "Security/SecPBKDF.h"
   9 #include "Security/pbkdf2.h"
  10
  11 #include <CommonCrypto/CommonHMAC.h>
  12 #include "Security/SecBase.h"
  13
  14 #include <stdlib.h>
  15 #include <string.h>
  16
  17 /* CC Based HMAC PRF functions */
  18 void hmac_sha1_PRF(const uint8_t *key,
  19                    size_t key_len,
  20                    const uint8_t *text,
  21                    size_t text_len,
  22                    uint8_t digest[CC_SHA1_DIGEST_LENGTH])
  23 {
  24     CCHmacContext hmac_sha1_context;
  25
  26     CCHmacInit(&hmac_sha1_context, kCCHmacAlgSHA1, key, key_len);
  27     CCHmacUpdate(&hmac_sha1_context, text, text_len);
  28     CCHmacFinal(&hmac_sha1_context, digest);
  29 }
  30
  31 void hmac_sha256_PRF(const uint8_t *key,
  32                    size_t key_len,
  33                    const uint8_t *text,
  34                    size_t text_len,
  35                    uint8_t digest[CC_SHA256_DIGEST_LENGTH])
  36 {
  37     CCHmacContext hmac_sha256_context;
  38
  39     CCHmacInit(&hmac_sha256_context, kCCHmacAlgSHA256, key, key_len);
  40     CCHmacUpdate(&hmac_sha256_context, text, text_len);
  41     CCHmacFinal(&hmac_sha256_context, digest);
  42 }
  43
  44
  45 /* This implements the HMAC SHA-1 version of pbkdf2 and allocates a local buffer for the HMAC */
  46 OSStatus pbkdf2_hmac_sha1(const uint8_t *passwordPtr, size_t passwordLen,
  47                       const uint8_t *saltPtr, size_t saltLen,
  48                       uint32_t iterationCount,
  49                       void *dkPtr, size_t dkLen)
  50 {
  51     // MAX(salt_length + 4, 20 /* SHA1 Digest size */) + 2 * 20;
  52     // salt_length + HASH_SIZE is bigger than either salt + 4 and digestSize.
  53     size_t kBigEnoughSize = (saltLen + CC_SHA1_DIGEST_LENGTH) + 2 * CC_SHA1_DIGEST_LENGTH;
  54     uint8_t *temp_data = malloc(kBigEnoughSize);
  55
  56     if (temp_data == NULL) {
  57         return errSecMemoryError;
  58     }
  59
  60     pbkdf2(hmac_sha1_PRF, CC_SHA1_DIGEST_LENGTH,
  61            passwordPtr, passwordLen,
  62            saltPtr, saltLen,
  63            iterationCount,
  64            dkPtr, dkLen,
  65            temp_data);
  66
  67     bzero(temp_data, kBigEnoughSize);
  68
  69     return errSecSuccess;
  70 }
  71
  72 /* This implements the HMAC SHA-256 version of pbkdf2 and allocates a local buffer for the HMAC */
  73 OSStatus pbkdf2_hmac_sha256(const uint8_t *passwordPtr, size_t passwordLen,
  74                       const uint8_t *saltPtr, size_t saltLen,
  75                       uint32_t iterationCount,
  76                       void *dkPtr, size_t dkLen)
  77 {
  78     // MAX(salt_length + 4, 32 /* SHA1 Digest size */) + 2 * 32;
  79     // salt_length + HASH_SIZE is bigger than either salt + 4 and digestSize.
  80     size_t kBigEnoughSize = (saltLen + CC_SHA256_DIGEST_LENGTH) + 2 * CC_SHA256_DIGEST_LENGTH;
  81     uint8_t *temp_data = malloc(kBigEnoughSize);
  82
  83     if (temp_data == NULL) {
  84         return errSecMemoryError;
  85     }
  86
  87     pbkdf2(hmac_sha256_PRF, CC_SHA256_DIGEST_LENGTH,
  88            passwordPtr, passwordLen,
  89            saltPtr, saltLen,
  90            iterationCount,
  91            dkPtr, dkLen,
  92            temp_data);
  93
  94     bzero(temp_data, kBigEnoughSize);
  95
  96     return errSecSuccess;
  97 }
  98
  99 OSStatus SecKeyFromPassphraseDataHMACSHA1(CFDataRef password, CFDataRef salt, uint32_t interationCount, CFMutableDataRef derivedKey)
 100 {
 101     return pbkdf2_hmac_sha1(CFDataGetBytePtr(password), CFDataGetLength(password),
 102                      CFDataGetBytePtr(salt), CFDataGetLength(salt),
 103                      interationCount,
 104                      CFDataGetMutableBytePtr(derivedKey), CFDataGetLength(derivedKey));
 105
 106 }
 107
 108 OSStatus SecKeyFromPassphraseDataHMACSHA256(CFDataRef password, CFDataRef salt, uint32_t interationCount, CFMutableDataRef derivedKey)
 109 {
 110     return pbkdf2_hmac_sha256(CFDataGetBytePtr(password), CFDataGetLength(password),
 111                        CFDataGetBytePtr(salt), CFDataGetLength(salt),
 112                        interationCount,
 113                        CFDataGetMutableBytePtr(derivedKey), CFDataGetLength(derivedKey));
 114
 115 }