aes.c

来自「在BOOTLOADR中增加当今最好AES加密技术,可用于客户远程更新应用程式」· C语言 代码 · 共 762 行 · 第 1/2 页

        }

        s0 =
            Te0(byte(t0, 3)) ^
            Te1(byte(t1, 2)) ^
            Te2(byte(t2, 1)) ^
            Te3(byte(t3, 0)) ^
            rk[0];
        s1 =
            Te0(byte(t1, 3)) ^
            Te1(byte(t2, 2)) ^
            Te2(byte(t3, 1)) ^
            Te3(byte(t0, 0)) ^
            rk[1];
        s2 =
            Te0(byte(t2, 3)) ^
            Te1(byte(t3, 2)) ^
            Te2(byte(t0, 1)) ^
            Te3(byte(t1, 0)) ^
            rk[2];
        s3 =
            Te0(byte(t3, 3)) ^
            Te1(byte(t0, 2)) ^
            Te2(byte(t1, 1)) ^
            Te3(byte(t2, 0)) ^
            rk[3];
    }

#endif

    /*
     * apply last round and
     * map cipher state to byte array block:
     */
    s0 =
        (Te4_3[byte(t0, 3)]) ^
        (Te4_2[byte(t1, 2)]) ^
        (Te4_1[byte(t2, 1)]) ^
        (Te4_0[byte(t3, 0)]) ^
        rk[0];
    STORE32H(s0, ct);
    s1 =
        (Te4_3[byte(t1, 3)]) ^
        (Te4_2[byte(t2, 2)]) ^
        (Te4_1[byte(t3, 1)]) ^
        (Te4_0[byte(t0, 0)]) ^
        rk[1];
    STORE32H(s1, ct+4);
    s2 =
        (Te4_3[byte(t2, 3)]) ^
        (Te4_2[byte(t3, 2)]) ^
        (Te4_1[byte(t0, 1)]) ^
        (Te4_0[byte(t1, 0)]) ^
        rk[2];
    STORE32H(s2, ct+8);
    s3 =
        (Te4_3[byte(t3, 3)]) ^
        (Te4_2[byte(t0, 2)]) ^
        (Te4_1[byte(t1, 1)]) ^
        (Te4_0[byte(t2, 0)]) ^
        rk[3];
    STORE32H(s3, ct+12);

    return CRYPT_OK;
}

#ifdef LTC_CLEAN_STACK
int ECB_ENC(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
{
   int err = _rijndael_ecb_encrypt(pt, ct, skey);
   burn_stack(sizeof(unsigned long)*8 + sizeof(unsigned long*) + sizeof(int)*2);
   return err;
}
#endif

#ifndef ENCRYPT_ONLY

/**
  Decrypts a block of text with AES
  @param ct The input ciphertext (16 bytes)
  @param pt The output plaintext (16 bytes)
  @param skey The key as scheduled
  @return CRYPT_OK if successful
*/
#ifdef LTC_CLEAN_STACK
static int _rijndael_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
#else
int ECB_DEC(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
#endif
{
    ulong32 s0, s1, s2, s3, t0, t1, t2, t3, *rk;
    int Nr, r;

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

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

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

#ifdef LTC_SMALL_CODE
    for (r = 0; ; r++) {
        rk += 4;
        t0 =
            Td0(byte(s0, 3)) ^
            Td1(byte(s3, 2)) ^
            Td2(byte(s2, 1)) ^
            Td3(byte(s1, 0)) ^
            rk[0];
        t1 =
            Td0(byte(s1, 3)) ^
            Td1(byte(s0, 2)) ^
            Td2(byte(s3, 1)) ^
            Td3(byte(s2, 0)) ^
            rk[1];
        t2 =
            Td0(byte(s2, 3)) ^
            Td1(byte(s1, 2)) ^
            Td2(byte(s0, 1)) ^
            Td3(byte(s3, 0)) ^
            rk[2];
        t3 =
            Td0(byte(s3, 3)) ^
            Td1(byte(s2, 2)) ^
            Td2(byte(s1, 1)) ^
            Td3(byte(s0, 0)) ^
            rk[3];
        if (r == Nr-2) {
           break;
        }
        s0 = t0; s1 = t1; s2 = t2; s3 = t3;
    }
    rk += 4;

#else

    /*
     * Nr - 1 full rounds:
     */
    r = Nr >> 1;
    for (;;) {

        t0 =
            Td0(byte(s0, 3)) ^
            Td1(byte(s3, 2)) ^
            Td2(byte(s2, 1)) ^
            Td3(byte(s1, 0)) ^
            rk[4];
        t1 =
            Td0(byte(s1, 3)) ^
            Td1(byte(s0, 2)) ^
            Td2(byte(s3, 1)) ^
            Td3(byte(s2, 0)) ^
            rk[5];
        t2 =
            Td0(byte(s2, 3)) ^
            Td1(byte(s1, 2)) ^
            Td2(byte(s0, 1)) ^
            Td3(byte(s3, 0)) ^
            rk[6];
        t3 =
            Td0(byte(s3, 3)) ^
            Td1(byte(s2, 2)) ^
            Td2(byte(s1, 1)) ^
            Td3(byte(s0, 0)) ^
            rk[7];

        rk += 8;
        if (--r == 0) {
            break;
        }


        s0 =
            Td0(byte(t0, 3)) ^
            Td1(byte(t3, 2)) ^
            Td2(byte(t2, 1)) ^
            Td3(byte(t1, 0)) ^
            rk[0];
        s1 =
            Td0(byte(t1, 3)) ^
            Td1(byte(t0, 2)) ^
            Td2(byte(t3, 1)) ^
            Td3(byte(t2, 0)) ^
            rk[1];
        s2 =
            Td0(byte(t2, 3)) ^
            Td1(byte(t1, 2)) ^
            Td2(byte(t0, 1)) ^
            Td3(byte(t3, 0)) ^
            rk[2];
        s3 =
            Td0(byte(t3, 3)) ^
            Td1(byte(t2, 2)) ^
            Td2(byte(t1, 1)) ^
            Td3(byte(t0, 0)) ^
            rk[3];
    }
#endif

    /*
     * apply last round and
     * map cipher state to byte array block:
     */
    s0 =
        (Td4[byte(t0, 3)] & 0xff000000) ^
        (Td4[byte(t3, 2)] & 0x00ff0000) ^
        (Td4[byte(t2, 1)] & 0x0000ff00) ^
        (Td4[byte(t1, 0)] & 0x000000ff) ^
        rk[0];
    STORE32H(s0, pt);
    s1 =
        (Td4[byte(t1, 3)] & 0xff000000) ^
        (Td4[byte(t0, 2)] & 0x00ff0000) ^
        (Td4[byte(t3, 1)] & 0x0000ff00) ^
        (Td4[byte(t2, 0)] & 0x000000ff) ^
        rk[1];
    STORE32H(s1, pt+4);
    s2 =
        (Td4[byte(t2, 3)] & 0xff000000) ^
        (Td4[byte(t1, 2)] & 0x00ff0000) ^
        (Td4[byte(t0, 1)] & 0x0000ff00) ^
        (Td4[byte(t3, 0)] & 0x000000ff) ^
        rk[2];
    STORE32H(s2, pt+8);
    s3 =
        (Td4[byte(t3, 3)] & 0xff000000) ^
        (Td4[byte(t2, 2)] & 0x00ff0000) ^
        (Td4[byte(t1, 1)] & 0x0000ff00) ^
        (Td4[byte(t0, 0)] & 0x000000ff) ^
        rk[3];
    STORE32H(s3, pt+12);

    return CRYPT_OK;
}


#ifdef LTC_CLEAN_STACK
int ECB_DEC(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
{
   int err = _rijndael_ecb_decrypt(ct, pt, skey);
   burn_stack(sizeof(unsigned long)*8 + sizeof(unsigned long*) + sizeof(int)*2);
   return err;
}
#endif

/**
  Performs a self-test of the AES block cipher
  @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled
*/
int ECB_TEST(void)
{
 #ifndef LTC_TEST
    return CRYPT_NOP;
 #else
 int err;
 static const struct {
     int keylen;
     unsigned char key[32], pt[16], ct[16];
 } tests[] = {
    { 16,
      { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
      { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
        0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff },
      { 0x69, 0xc4, 0xe0, 0xd8, 0x6a, 0x7b, 0x04, 0x30,
        0xd8, 0xcd, 0xb7, 0x80, 0x70, 0xb4, 0xc5, 0x5a }
    }, {
      24,
      { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 },
      { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
        0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff },
      { 0xdd, 0xa9, 0x7c, 0xa4, 0x86, 0x4c, 0xdf, 0xe0,
        0x6e, 0xaf, 0x70, 0xa0, 0xec, 0x0d, 0x71, 0x91 }
    }, {
      32,
      { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f },
      { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
        0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff },
      { 0x8e, 0xa2, 0xb7, 0xca, 0x51, 0x67, 0x45, 0xbf,
        0xea, 0xfc, 0x49, 0x90, 0x4b, 0x49, 0x60, 0x89 }
    }
 };

 symmetric_key key;
 unsigned char tmp[2][16];
 int i, y;

 for (i = 0; i < (int)(sizeof(tests)/sizeof(tests[0])); i++) {
    zeromem(&key, sizeof(key));
    if ((err = rijndael_setup(tests[i].key, tests[i].keylen, 0, &key)) != CRYPT_OK) {
       return err;
    }

    rijndael_ecb_encrypt(tests[i].pt, tmp[0], &key);
    rijndael_ecb_decrypt(tmp[0], tmp[1], &key);
    if (memcmp(tmp[0], tests[i].ct, 16) || memcmp(tmp[1], tests[i].pt, 16)) {
#if 0
       printf("\n\nTest %d failed\n", i);
       if (memcmp(tmp[0], tests[i].ct, 16)) {
          printf("CT: ");
          for (i = 0; i < 16; i++) {
             printf("%02x ", tmp[0][i]);
          }
          printf("\n");
       } else {
          printf("PT: ");
          for (i = 0; i < 16; i++) {
             printf("%02x ", tmp[1][i]);
          }
          printf("\n");
       }
#endif
        return CRYPT_FAIL_TESTVECTOR;
    }

      /* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */
      for (y = 0; y < 16; y++) tmp[0][y] = 0;
      for (y = 0; y < 1000; y++) rijndael_ecb_encrypt(tmp[0], tmp[0], &key);
      for (y = 0; y < 1000; y++) rijndael_ecb_decrypt(tmp[0], tmp[0], &key);
      for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
 }
 return CRYPT_OK;
 #endif
}

#endif /* ENCRYPT_ONLY */


/** Terminate the context
   @param skey    The scheduled key
*/
void ECB_DONE(symmetric_key *skey)
{
}


/**
  Gets suitable key size
  @param keysize [in/out] The length of the recommended key (in bytes).  This function will store the suitable size back in this variable.
  @return CRYPT_OK if the input key size is acceptable.
*/
int ECB_KS(int *keysize)
{
   LTC_ARGCHK(keysize != NULL);

   if (*keysize < 16)
      return CRYPT_INVALID_KEYSIZE;
   if (*keysize < 24) {
      *keysize = 16;
      return CRYPT_OK;
   } else if (*keysize < 32) {
      *keysize = 24;
      return CRYPT_OK;
   } else {
      *keysize = 32;
      return CRYPT_OK;
   }
}

#endif


/* $Source: /cvs/libtom/libtomcrypt/src/ciphers/aes/aes.c,v $ */
/* $Revision: 1.11 $ */
/* $Date: 2006/03/31 14:15:34 $ */