src/libfreeswan/libcrypto/libaes/aes_xcbc_mac.c

   1 #ifdef __KERNEL__
   2 #include <linux/types.h>
   3 #include <linux/kernel.h>
   4 #define DEBUG(x)
   5 #else
   6 #include <stdio.h>
   7 #include <sys/types.h>
   8 #define DEBUG(x) x
   9 #endif
  10
  11 #include "aes.h"
  12 #include "aes_xcbc_mac.h"
  13
  14 int AES_xcbc_mac_set_key(aes_context_mac *ctxm, const u_int8_t *key, int keylen)
  15 {
  16         int ret=1;
  17         aes_block kn[3] = {
  18                 { 0x01010101, 0x01010101, 0x01010101, 0x01010101 },
  19                 { 0x02020202, 0x02020202, 0x02020202, 0x02020202 },
  20                 { 0x03030303, 0x03030303, 0x03030303, 0x03030303 },
  21         };
  22         aes_set_key(&ctxm->ctx_k1, key, keylen, 0);
  23         aes_encrypt(&ctxm->ctx_k1, (u_int8_t *) kn[0], (u_int8_t *) kn[0]);
  24         aes_encrypt(&ctxm->ctx_k1, (u_int8_t *) kn[1], (u_int8_t *) ctxm->k2);
  25         aes_encrypt(&ctxm->ctx_k1, (u_int8_t *) kn[2], (u_int8_t *) ctxm->k3);
  26         aes_set_key(&ctxm->ctx_k1, (u_int8_t *) kn[0], 16, 0);
  27         return ret;
  28 }
  29 static void do_pad_xor(u_int8_t *out, const u_int8_t *in, int len) {
  30         int pos=0;
  31         for (pos=1; pos <= 16; pos++, in++, out++) {
  32                 if (pos <= len)
  33                         *out ^= *in;
  34                 if (pos > len) {
  35                         DEBUG(printf("put 0x80 at pos=%d\n", pos));
  36                         *out ^= 0x80;
  37                         break;
  38                 }
  39         }
  40 }
  41 static void xor_block(aes_block res, const aes_block op) {
  42         res[0] ^= op[0];
  43         res[1] ^= op[1];
  44         res[2] ^= op[2];
  45         res[3] ^= op[3];
  46 }
  47 int AES_xcbc_mac_hash(const aes_context_mac *ctxm, const u_int8_t * in, int ilen, u_int8_t hash[16]) {
  48         int ret=ilen;
  49         u_int32_t out[4] = { 0, 0, 0, 0 };
  50         for (; ilen > 16 ; ilen-=16) {
  51                 xor_block(out, (const u_int32_t*) &in[0]);
  52                 aes_encrypt(&ctxm->ctx_k1, in, (u_int8_t *)&out[0]);
  53                 in+=16;
  54         }
  55         do_pad_xor((u_int8_t *)&out, in, ilen);
  56         if (ilen==16) {
  57                 DEBUG(printf("using k3\n"));
  58                 xor_block(out, ctxm->k3);
  59         }
  60         else
  61         {
  62                 DEBUG(printf("using k2\n"));
  63                 xor_block(out, ctxm->k2);
  64         }
  65         aes_encrypt(&ctxm->ctx_k1, (u_int8_t *)out, hash);
  66         return ret;
  67 }