view libtomcrypt/src/hashes/sha2/sha224.c @ 994:5c5ade336926

Prefer stronger algorithms in algorithm negotiation. Prefer diffie-hellman-group14-sha1 (2048 bit) over diffie-hellman-group1-sha1 (1024 bit). Due to meet-in-the-middle attacks the effective key length of three key 3DES is 112 bits. AES is stronger and faster then 3DES. Prefer to delay the start of compression until after authentication has completed. This avoids exposing compression code to attacks from unauthenticated users. (github pull request #9)
author Fedor Brunner <fedor.brunner@azet.sk>
date Fri, 23 Jan 2015 23:00:25 +0800
parents 0cbe8f6dbf9e
children f849a5ca2efc
line wrap: on
line source

/* 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
 * guarantee it works.
 *
 * Tom St Denis, [email protected], http://libtomcrypt.com
 */
/**
   @param sha224.c
   SHA-224 new NIST standard based off of SHA-256 truncated to 224 bits (Tom St Denis)
*/

const struct ltc_hash_descriptor sha224_desc =
{
    "sha224",
    10,
    28,
    64,

    /* OID */
   { 2, 16, 840, 1, 101, 3, 4, 2, 4,  },
   9,

    &sha224_init,
    &sha256_process,
    &sha224_done,
    &sha224_test,
    NULL
};

/* init the sha256 er... sha224 state ;-) */
/**
   Initialize the hash state
   @param md   The hash state you wish to initialize
   @return CRYPT_OK if successful
*/
int sha224_init(hash_state * md)
{
    LTC_ARGCHK(md != NULL);

    md->sha256.curlen = 0;
    md->sha256.length = 0;
    md->sha256.state[0] = 0xc1059ed8UL;
    md->sha256.state[1] = 0x367cd507UL;
    md->sha256.state[2] = 0x3070dd17UL;
    md->sha256.state[3] = 0xf70e5939UL;
    md->sha256.state[4] = 0xffc00b31UL;
    md->sha256.state[5] = 0x68581511UL;
    md->sha256.state[6] = 0x64f98fa7UL;
    md->sha256.state[7] = 0xbefa4fa4UL;
    return CRYPT_OK;
}

/**
   Terminate the hash to get the digest
   @param md  The hash state
   @param out [out] The destination of the hash (28 bytes)
   @return CRYPT_OK if successful
*/
int sha224_done(hash_state * md, unsigned char *out)
{
    unsigned char buf[32];
    int err;

    LTC_ARGCHK(md  != NULL);
    LTC_ARGCHK(out != NULL);

    err = sha256_done(md, buf);
    XMEMCPY(out, buf, 28);
#ifdef LTC_CLEAN_STACK
    zeromem(buf, sizeof(buf));
#endif 
    return err;
}

/**
  Self-test the hash
  @return CRYPT_OK if successful, CRYPT_NOP if self-tests have been disabled
*/  
int  sha224_test(void)
{
 #ifndef LTC_TEST
    return CRYPT_NOP;
 #else    
  static const struct {
      char *msg;
      unsigned char hash[28];
  } tests[] = {
    { "abc",
      { 0x23, 0x09, 0x7d, 0x22, 0x34, 0x05, 0xd8,
        0x22, 0x86, 0x42, 0xa4, 0x77, 0xbd, 0xa2,
        0x55, 0xb3, 0x2a, 0xad, 0xbc, 0xe4, 0xbd,
        0xa0, 0xb3, 0xf7, 0xe3, 0x6c, 0x9d, 0xa7 }
    },
    { "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
      { 0x75, 0x38, 0x8b, 0x16, 0x51, 0x27, 0x76,
        0xcc, 0x5d, 0xba, 0x5d, 0xa1, 0xfd, 0x89,
        0x01, 0x50, 0xb0, 0xc6, 0x45, 0x5c, 0xb4,
        0xf5, 0x8b, 0x19, 0x52, 0x52, 0x25, 0x25 }
    },
  };

  int i;
  unsigned char tmp[28];
  hash_state md;

  for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
      sha224_init(&md);
      sha224_process(&md, (unsigned char*)tests[i].msg, (unsigned long)strlen(tests[i].msg));
      sha224_done(&md, tmp);
      if (XMEMCMP(tmp, tests[i].hash, 28) != 0) {
         return CRYPT_FAIL_TESTVECTOR;
      }
  }
  return CRYPT_OK;
 #endif
}


/* $Source: /cvs/libtom/libtomcrypt/src/hashes/sha2/sha224.c,v $ */
/* $Revision: 1.8 $ */
/* $Date: 2006/11/01 09:28:17 $ */