view libtomcrypt/src/hashes/sha2/sha224.c @ 1715:3974f087d9c0

Disallow leading lines before the ident for server (#102) Per RFC4253 4.2 clients must be able to process other lines of data before the version string, server behavior is not defined neither with MUST/SHOULD nor with MAY. If server process up to 50 lines too - it may cause too long hanging session with invalid/evil client that consume host resources and potentially may lead to DDoS on poor embedded boxes. Let's require first line from client to be version string and fail early if it's not - matches both RFC and real OpenSSH behavior.
author Vladislav Grishenko <themiron@users.noreply.github.com>
date Mon, 15 Jun 2020 18:22:18 +0500
parents 6dba84798cd5
children
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/* 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.
 */
/**
   @param sha224.c
   LTC_SHA-224 new NIST standard based off of LTC_SHA-256 truncated to 224 bits (Tom St Denis)
*/

#include "tomcrypt.h"

#if defined(LTC_SHA224) && defined(LTC_SHA256)

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 {
      const 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 (compare_testvector(tmp, sizeof(tmp), tests[i].hash, sizeof(tests[i].hash), "SHA224", i)) {
         return CRYPT_FAIL_TESTVECTOR;
      }
  }
  return CRYPT_OK;
 #endif
}

#endif /* defined(LTC_SHA224) && defined(LTC_SHA256) */


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