src/crypto/sha384.c

   1 /*
   2  * SHA-384 hash implementation and interface functions
   3  * Copyright (c) 2003-2017, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10
  11 #include "common.h"
  12 #include "sha384.h"
  13 #include "crypto.h"
  14
  15
  16 /**
  17  * hmac_sha384_vector - HMAC-SHA384 over data vector (RFC 2104)
  18  * @key: Key for HMAC operations
  19  * @key_len: Length of the key in bytes
  20  * @num_elem: Number of elements in the data vector
  21  * @addr: Pointers to the data areas
  22  * @len: Lengths of the data blocks
  23  * @mac: Buffer for the hash (48 bytes)
  24  * Returns: 0 on success, -1 on failure
  25  */
  26 int hmac_sha384_vector(const u8 *key, size_t key_len, size_t num_elem,
  27                        const u8 *addr[], const size_t *len, u8 *mac)
  28 {
  29         unsigned char k_pad[128]; /* padding - key XORd with ipad/opad */
  30         unsigned char tk[48];
  31         const u8 *_addr[6];
  32         size_t _len[6], i;
  33
  34         if (num_elem > 5) {
  35                 /*
  36                  * Fixed limit on the number of fragments to avoid having to
  37                  * allocate memory (which could fail).
  38                  */
  39                 return -1;
  40         }
  41
  42         /* if key is longer than 128 bytes reset it to key = SHA384(key) */
  43         if (key_len > 128) {
  44                 if (sha384_vector(1, &key, &key_len, tk) < 0)
  45                         return -1;
  46                 key = tk;
  47                 key_len = 48;
  48         }
  49
  50         /* the HMAC_SHA384 transform looks like:
  51          *
  52          * SHA384(K XOR opad, SHA384(K XOR ipad, text))
  53          *
  54          * where K is an n byte key
  55          * ipad is the byte 0x36 repeated 128 times
  56          * opad is the byte 0x5c repeated 128 times
  57          * and text is the data being protected */
  58
  59         /* start out by storing key in ipad */
  60         os_memset(k_pad, 0, sizeof(k_pad));
  61         os_memcpy(k_pad, key, key_len);
  62         /* XOR key with ipad values */
  63         for (i = 0; i < 128; i++)
  64                 k_pad[i] ^= 0x36;
  65
  66         /* perform inner SHA384 */
  67         _addr[0] = k_pad;
  68         _len[0] = 128;
  69         for (i = 0; i < num_elem; i++) {
  70                 _addr[i + 1] = addr[i];
  71                 _len[i + 1] = len[i];
  72         }
  73         if (sha384_vector(1 + num_elem, _addr, _len, mac) < 0)
  74                 return -1;
  75
  76         os_memset(k_pad, 0, sizeof(k_pad));
  77         os_memcpy(k_pad, key, key_len);
  78         /* XOR key with opad values */
  79         for (i = 0; i < 128; i++)
  80                 k_pad[i] ^= 0x5c;
  81
  82         /* perform outer SHA384 */
  83         _addr[0] = k_pad;
  84         _len[0] = 128;
  85         _addr[1] = mac;
  86         _len[1] = SHA384_MAC_LEN;
  87         return sha384_vector(2, _addr, _len, mac);
  88 }
  89
  90
  91 /**
  92  * hmac_sha384 - HMAC-SHA384 over data buffer (RFC 2104)
  93  * @key: Key for HMAC operations
  94  * @key_len: Length of the key in bytes
  95  * @data: Pointers to the data area
  96  * @data_len: Length of the data area
  97  * @mac: Buffer for the hash (48 bytes)
  98  * Returns: 0 on success, -1 on failure
  99  */
 100 int hmac_sha384(const u8 *key, size_t key_len, const u8 *data,
 101                 size_t data_len, u8 *mac)
 102 {
 103         return hmac_sha384_vector(key, key_len, 1, &data, &data_len, mac);
 104 }