aes.c

CROSSCRYPT是FILEDISK的拓展

/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * gurantee it works.
 *
 * Tom St Denis, [e-mail], http://libtomcrypt.org
 */

/* AES implementation by Tom St Denis
 *
 * Derived from the Public Domain source code by

---
  * rijndael-alg-fst.c
  *
  * @version 3.0 (December 2000)
  *
  * Optimised ANSI C code for the Rijndael cipher (now AES)
  *
  * @author Vincent Rijmen <[e-mail]>
  * @author Antoon Bosselaers <[e-mail]>
  * @author Paulo Barreto <[e-mail]>
---

  modified by Stefan Scherrer to allow compilation under DDK

 */

#include "tom.h"

#define byte(x, n) ((unsigned char)((x) >> (8 * (n))))


#if 0
const struct _cipher_descriptor rijndael_desc =
{
    "rijndael",
    6,
    16, 32, 16, 10,
    &rijndael_setup,
    &rijndael_ecb_encrypt,
    &rijndael_ecb_decrypt,
    &rijndael_test,
    &rijndael_keysize
};

const struct _cipher_descriptor aes_desc =
{
    "aes",
    6,
    16, 32, 16, 10,
    &rijndael_setup,
    &rijndael_ecb_encrypt,
    &rijndael_ecb_decrypt,
    &rijndael_test,
    &rijndael_keysize
};
#endif

#include "aes_tab.c"

int rijndael_setup(const unsigned char *key, int keylen, int rounds, symmetric_key *skey)
{
    int i, j;
    ulong32 temp, *rk, *rrk;

    _ARGCHK(key != NULL);
    _ARGCHK(skey != NULL);

    if (keylen != 16 && keylen != 24 && keylen != 32) {
       return CRYPT_INVALID_KEYSIZE;
    }

    if (rounds != 0 && rounds != (10 + ((keylen/8)-2)*2)) {
       return CRYPT_INVALID_ROUNDS;
    }

    skey->rijndael.Nr = 10 + ((keylen/8)-2)*2;

    /* setup the forward key */
    i                 = 0;
    rk                = skey->rijndael.eK;
    LOAD32H(rk[0], key     );
    LOAD32H(rk[1], key +  4);
    LOAD32H(rk[2], key +  8);
    LOAD32H(rk[3], key + 12);
    if (keylen == 16) {
        j = 44;
        for (;;) {
            temp  = rk[3];
            rk[4] = rk[0] ^
                (Te4_3[byte(temp, 2)]) ^
                (Te4_2[byte(temp, 1)]) ^
                (Te4_1[byte(temp, 0)]) ^
                (Te4_0[byte(temp, 3)]) ^
                rcon[i];
            rk[5] = rk[1] ^ rk[4];
            rk[6] = rk[2] ^ rk[5];
            rk[7] = rk[3] ^ rk[6];
            if (++i == 10) {
               break;
            }
            rk += 4;
        }
    } else if (keylen == 24) {
        j = 52;
        LOAD32H(rk[4], key + 16);
        LOAD32H(rk[5], key + 20);
        for (;;) {
        #ifdef _MSC_VER
            temp = skey->rijndael.eK[rk - skey->rijndael.eK + 5];
        #else
            temp = rk[5];
        #endif
            rk[ 6] = rk[ 0] ^
                (Te4_3[byte(temp, 2)]) ^
                (Te4_2[byte(temp, 1)]) ^
                (Te4_1[byte(temp, 0)]) ^
                (Te4_0[byte(temp, 3)]) ^
                rcon[i];
            rk[ 7] = rk[ 1] ^ rk[ 6];
            rk[ 8] = rk[ 2] ^ rk[ 7];
            rk[ 9] = rk[ 3] ^ rk[ 8];
            if (++i == 8) {
                break;
            }
            rk[10] = rk[ 4] ^ rk[ 9];
            rk[11] = rk[ 5] ^ rk[10];
            rk += 6;
        }
    } else if (keylen == 32) {
        j = 60;
        LOAD32H(rk[4], key + 16);
        LOAD32H(rk[5], key + 20);
        LOAD32H(rk[6], key + 24);
        LOAD32H(rk[7], key + 28);
        for (;;) {
        #ifdef _MSC_VER
            temp = skey->rijndael.eK[rk - skey->rijndael.eK + 7];
        #else
            temp = rk[7];
        #endif
            rk[ 8] = rk[ 0] ^
                (Te4_3[byte(temp, 2)]) ^
                (Te4_2[byte(temp, 1)]) ^
                (Te4_1[byte(temp, 0)]) ^
                (Te4_0[byte(temp, 3)]) ^
                rcon[i];
            rk[ 9] = rk[ 1] ^ rk[ 8];
            rk[10] = rk[ 2] ^ rk[ 9];
            rk[11] = rk[ 3] ^ rk[10];
            if (++i == 7) {
                break;
            }
            temp = rk[11];
            rk[12] = rk[ 4] ^
                (Te4_3[byte(temp, 3)]) ^
                (Te4_2[byte(temp, 2)]) ^
                (Te4_1[byte(temp, 1)]) ^
                (Te4_0[byte(temp, 0)]);
            rk[13] = rk[ 5] ^ rk[12];
            rk[14] = rk[ 6] ^ rk[13];
            rk[15] = rk[ 7] ^ rk[14];
            rk += 8;
        }
    } else {
       /* this can't happen */
       j = 4;
    }

    /* setup the inverse key now */
    rk   = skey->rijndael.dK;
    rrk  = skey->rijndael.eK + j - 4;

    /* apply the inverse MixColumn transform to all round keys but the first and the last: */
    /* copy first */
    *rk++ = *rrk++;
    *rk++ = *rrk++;
    *rk++ = *rrk++;
    *rk   = *rrk;
    rk -= 3; rrk -= 3;

    for (i = 1; i < skey->rijndael.Nr; i++) {
        rrk -= 4;
        rk  += 4;
    #ifdef SMALL_CODE
        temp = rrk[0];
        rk[0] =
            Td0[255 & Te4[byte(temp, 3)]] ^
            Td1[255 & Te4[byte(temp, 2)]] ^
            Td2[255 & Te4[byte(temp, 1)]] ^
            Td3[255 & Te4[byte(temp, 0)]];
        temp = rrk[1];
        rk[1] =
            Td0[255 & Te4[byte(temp, 3)]] ^
            Td1[255 & Te4[byte(temp, 2)]] ^
            Td2[255 & Te4[byte(temp, 1)]] ^
            Td3[255 & Te4[byte(temp, 0)]];
        temp = rrk[2];
        rk[2] =
            Td0[255 & Te4[byte(temp, 3)]] ^
            Td1[255 & Te4[byte(temp, 2)]] ^
            Td2[255 & Te4[byte(temp, 1)]] ^
            Td3[255 & Te4[byte(temp, 0)]];
        temp = rrk[3];
        rk[3] =
            Td0[255 & Te4[byte(temp, 3)]] ^
            Td1[255 & Te4[byte(temp, 2)]] ^
            Td2[255 & Te4[byte(temp, 1)]] ^
            Td3[255 & Te4[byte(temp, 0)]];
     #else
        temp = rrk[0];
        rk[0] =
            Tks0[byte(temp, 3)] ^
            Tks1[byte(temp, 2)] ^
            Tks2[byte(temp, 1)] ^
            Tks3[byte(temp, 0)];
        temp = rrk[1];
        rk[1] =
            Tks0[byte(temp, 3)] ^
            Tks1[byte(temp, 2)] ^
            Tks2[byte(temp, 1)] ^
            Tks3[byte(temp, 0)];
        temp = rrk[2];
        rk[2] =
            Tks0[byte(temp, 3)] ^
            Tks1[byte(temp, 2)] ^
            Tks2[byte(temp, 1)] ^
            Tks3[byte(temp, 0)];
        temp = rrk[3];
        rk[3] =
            Tks0[byte(temp, 3)] ^
            Tks1[byte(temp, 2)] ^
            Tks2[byte(temp, 1)] ^
            Tks3[byte(temp, 0)];
      #endif

    }

    /* copy last */
    rrk -= 4;
    rk  += 4;
    *rk++ = *rrk++;
    *rk++ = *rrk++;
    *rk++ = *rrk++;
    *rk   = *rrk;

    return CRYPT_OK;
}

#ifdef CLEAN_STACK
static void _rijndael_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
#else
void rijndael_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
#endif
{
    ulong32 s0, s1, s2, s3, t0, t1, t2, t3, *rk;
    int Nr, r;

    _ARGCHK(pt != NULL);
    _ARGCHK(ct != NULL);
    _ARGCHK(skey != NULL);

    Nr = skey->rijndael.Nr;
    rk = skey->rijndael.eK;

    /*
     * map byte array block to cipher state
     * and add initial round key:
     */
    LOAD32H(s0, pt      ); s0 ^= rk[0];
    LOAD32H(s1, pt  +  4); s1 ^= rk[1];
    LOAD32H(s2, pt  +  8); s2 ^= rk[2];
    LOAD32H(s3, pt  + 12); s3 ^= rk[3];

    /*
     * Nr - 1 full rounds:
     */
    r = Nr >> 1;
    for (;;) {
        t0 =
            Te0[byte(s0, 3)] ^
            Te1[byte(s1, 2)] ^
            Te2[byte(s2, 1)] ^
            Te3[byte(s3, 0)] ^
            rk[4];
        t1 =
            Te0[byte(s1, 3)] ^
            Te1[byte(s2, 2)] ^
            Te2[byte(s3, 1)] ^
            Te3[byte(s0, 0)] ^
            rk[5];
        t2 =
            Te0[byte(s2, 3)] ^
            Te1[byte(s3, 2)] ^
            Te2[byte(s0, 1)] ^
            Te3[byte(s1, 0)] ^
            rk[6];
        t3 =
            Te0[byte(s3, 3)] ^
            Te1[byte(s0, 2)] ^
            Te2[byte(s1, 1)] ^