/*

 * SHA-512 hash implementation and interface functions

 * Copyright (c) 2015, Pali Rohár <pali.rohar@gmail.com>

 *

 * This software may be distributed under the terms of the BSD license.

 * See README for more details.

 */

#include "includes.h"

#include "common.h"

#include "sha512_i.h"

#include "crypto.h"

/**

 * sha512_vector - SHA512 hash for data vector

 * @num_elem: Number of elements in the data vector

 * @addr: Pointers to the data areas

 * @len: Lengths of the data blocks

 * @mac: Buffer for the hash

 * Returns: 0 on success, -1 of failure

 */

int sha512_vector(size_t num_elem, const u8 *addr[], const size_t *len,

      u8 *mac)

{

  struct sha512_state ctx;

  size_t i;

  sha512_init(&ctx);

  for (i = 0; i < num_elem; i++)

    if (sha512_process(&ctx, addr[i], len[i]))

      return -1;

  if (sha512_done(&ctx, mac))

    return -1;

  return 0;

}

/* ===== start - public domain SHA512 implementation ===== */

/* This is based on SHA512 implementation in LibTomCrypt that was released into

 * public domain by Tom St Denis. */

#define CONST64(n) n ## ULL

/* the K array */

static const u64 K[80] = {

  CONST64(0x428a2f98d728ae22), CONST64(0x7137449123ef65cd),

  CONST64(0xb5c0fbcfec4d3b2f), CONST64(0xe9b5dba58189dbbc),

  CONST64(0x3956c25bf348b538), CONST64(0x59f111f1b605d019),

  CONST64(0x923f82a4af194f9b), CONST64(0xab1c5ed5da6d8118),

  CONST64(0xd807aa98a3030242), CONST64(0x12835b0145706fbe),

  CONST64(0x243185be4ee4b28c), CONST64(0x550c7dc3d5ffb4e2),

  CONST64(0x72be5d74f27b896f), CONST64(0x80deb1fe3b1696b1),

  CONST64(0x9bdc06a725c71235), CONST64(0xc19bf174cf692694),

  CONST64(0xe49b69c19ef14ad2), CONST64(0xefbe4786384f25e3),

  CONST64(0x0fc19dc68b8cd5b5), CONST64(0x240ca1cc77ac9c65),

  CONST64(0x2de92c6f592b0275), CONST64(0x4a7484aa6ea6e483),

  CONST64(0x5cb0a9dcbd41fbd4), CONST64(0x76f988da831153b5),

  CONST64(0x983e5152ee66dfab), CONST64(0xa831c66d2db43210),

  CONST64(0xb00327c898fb213f), CONST64(0xbf597fc7beef0ee4),

  CONST64(0xc6e00bf33da88fc2), CONST64(0xd5a79147930aa725),

  CONST64(0x06ca6351e003826f), CONST64(0x142929670a0e6e70),

  CONST64(0x27b70a8546d22ffc), CONST64(0x2e1b21385c26c926),

  CONST64(0x4d2c6dfc5ac42aed), CONST64(0x53380d139d95b3df),

  CONST64(0x650a73548baf63de), CONST64(0x766a0abb3c77b2a8),

  CONST64(0x81c2c92e47edaee6), CONST64(0x92722c851482353b),

  CONST64(0xa2bfe8a14cf10364), CONST64(0xa81a664bbc423001),

  CONST64(0xc24b8b70d0f89791), CONST64(0xc76c51a30654be30),

  CONST64(0xd192e819d6ef5218), CONST64(0xd69906245565a910),

  CONST64(0xf40e35855771202a), CONST64(0x106aa07032bbd1b8),

  CONST64(0x19a4c116b8d2d0c8), CONST64(0x1e376c085141ab53),

  CONST64(0x2748774cdf8eeb99), CONST64(0x34b0bcb5e19b48a8),

  CONST64(0x391c0cb3c5c95a63), CONST64(0x4ed8aa4ae3418acb),

  CONST64(0x5b9cca4f7763e373), CONST64(0x682e6ff3d6b2b8a3),

  CONST64(0x748f82ee5defb2fc), CONST64(0x78a5636f43172f60),

  CONST64(0x84c87814a1f0ab72), CONST64(0x8cc702081a6439ec),

  CONST64(0x90befffa23631e28), CONST64(0xa4506cebde82bde9),

  CONST64(0xbef9a3f7b2c67915), CONST64(0xc67178f2e372532b),

  CONST64(0xca273eceea26619c), CONST64(0xd186b8c721c0c207),

  CONST64(0xeada7dd6cde0eb1e), CONST64(0xf57d4f7fee6ed178),

  CONST64(0x06f067aa72176fba), CONST64(0x0a637dc5a2c898a6),

  CONST64(0x113f9804bef90dae), CONST64(0x1b710b35131c471b),

  CONST64(0x28db77f523047d84), CONST64(0x32caab7b40c72493),

  CONST64(0x3c9ebe0a15c9bebc), CONST64(0x431d67c49c100d4c),

  CONST64(0x4cc5d4becb3e42b6), CONST64(0x597f299cfc657e2a),

  CONST64(0x5fcb6fab3ad6faec), CONST64(0x6c44198c4a475817)

};

/* Various logical functions */

#define Ch(x,y,z)       (z ^ (x & (y ^ z)))

#define Maj(x,y,z)      (((x | y) & z) | (x & y))

#define S(x, n)         ROR64c(x, n)

#define R(x, n)         (((x) & CONST64(0xFFFFFFFFFFFFFFFF)) >> ((u64) n))

#define Sigma0(x)       (S(x, 28) ^ S(x, 34) ^ S(x, 39))

#define Sigma1(x)       (S(x, 14) ^ S(x, 18) ^ S(x, 41))

#define Gamma0(x)       (S(x, 1) ^ S(x, 8) ^ R(x, 7))

#define Gamma1(x)       (S(x, 19) ^ S(x, 61) ^ R(x, 6))

#define ROR64c(x, y) \

    ( ((((x) & CONST64(0xFFFFFFFFFFFFFFFF)) >> ((u64) (y) & CONST64(63))) | \

      ((x) << ((u64) (64 - ((y) & CONST64(63)))))) & \

      CONST64(0xFFFFFFFFFFFFFFFF))

/* compress 1024-bits */

static int sha512_compress(struct sha512_state *md, unsigned char *buf)

{

  u64 S[8], t0, t1;

  u64 *W;

  int i;

  W = os_malloc(80 * sizeof(u64));

  if (!W)

    return -1;

  /* copy state into S */

  for (i = 0; i < 8; i++) {

    S[i] = md->state[i];

  }

  /* copy the state into 1024-bits into W[0..15] */

  for (i = 0; i < 16; i++)

    W[i] = WPA_GET_BE64(buf + (8 * i));

  /* fill W[16..79] */

  for (i = 16; i < 80; i++) {

    W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) +

      W[i - 16];

  }

  /* Compress */

  for (i = 0; i < 80; i++) {

    t0 = S[7] + Sigma1(S[4]) + Ch(S[4], S[5], S[6]) + K[i] + W[i];

    t1 = Sigma0(S[0]) + Maj(S[0], S[1], S[2]);

    S[7] = S[6];

    S[6] = S[5];

    S[5] = S[4];

    S[4] = S[3] + t0;

    S[3] = S[2];

    S[2] = S[1];

    S[1] = S[0];

    S[0] = t0 + t1;

  }

  /* feedback */

  for (i = 0; i < 8; i++) {

    md->state[i] = md->state[i] + S[i];

  }

  os_free(W);

  return 0;

}

/**

   Initialize the hash state

   @param md   The hash state you wish to initialize

   @return CRYPT_OK if successful

*/

void sha512_init(struct sha512_state *md)

{

  md->curlen = 0;

  md->length = 0;

  md->state[0] = CONST64(0x6a09e667f3bcc908);

  md->state[1] = CONST64(0xbb67ae8584caa73b);

  md->state[2] = CONST64(0x3c6ef372fe94f82b);

  md->state[3] = CONST64(0xa54ff53a5f1d36f1);

  md->state[4] = CONST64(0x510e527fade682d1);

  md->state[5] = CONST64(0x9b05688c2b3e6c1f);

  md->state[6] = CONST64(0x1f83d9abfb41bd6b);

  md->state[7] = CONST64(0x5be0cd19137e2179);

}

/**

   Process a block of memory though the hash

   @param md     The hash state

   @param in     The data to hash

   @param inlen  The length of the data (octets)

   @return CRYPT_OK if successful

*/

int sha512_process(struct sha512_state *md, const unsigned char *in,

       unsigned long inlen)

{

  unsigned long n;

  if (md->curlen >= sizeof(md->buf))

    return -1;

  while (inlen > 0) {

    if (md->curlen == 0 && inlen >= SHA512_BLOCK_SIZE) {

      if (sha512_compress(md, (unsigned char *) in) < 0)

        return -1;

      md->length += SHA512_BLOCK_SIZE * 8;

      in += SHA512_BLOCK_SIZE;

      inlen -= SHA512_BLOCK_SIZE;

    } else {

      n = MIN(inlen, (SHA512_BLOCK_SIZE - md->curlen));

      os_memcpy(md->buf + md->curlen, in, n);

      md->curlen += n;

      in += n;

      inlen -= n;

      if (md->curlen == SHA512_BLOCK_SIZE) {

        if (sha512_compress(md, md->buf) < 0)

          return -1;

        md->length += 8 * SHA512_BLOCK_SIZE;

        md->curlen = 0;

      }

    }

  }

  return 0;

}

/**

   Terminate the hash to get the digest

   @param md  The hash state

   @param out [out] The destination of the hash (64 bytes)

   @return CRYPT_OK if successful

*/

int sha512_done(struct sha512_state *md, unsigned char *out)

{

  int i;

  if (md->curlen >= sizeof(md->buf))

    return -1;

  /* increase the length of the message */

  md->length += md->curlen * CONST64(8);

  /* append the '1' bit */

  md->buf[md->curlen++] = (unsigned char) 0x80;

  /* if the length is currently above 112 bytes we append zeros

   * then compress.  Then we can fall back to padding zeros and length

   * encoding like normal.

   */

  if (md->curlen > 112) {

    while (md->curlen < 128) {

      md->buf[md->curlen++] = (unsigned char) 0;

    }

    sha512_compress(md, md->buf);

    md->curlen = 0;

  }

  /* pad up to 120 bytes of zeroes

   * note: that from 112 to 120 is the 64 MSB of the length.  We assume

   * that you won't hash > 2^64 bits of data... :-)

   */

  while (md->curlen < 120) {

    md->buf[md->curlen++] = (unsigned char) 0;

  }

  /* store length */

  WPA_PUT_BE64(md->buf + 120, md->length);

  sha512_compress(md, md->buf);

  /* copy output */

  for (i = 0; i < 8; i++)

    WPA_PUT_BE64(out + (8 * i), md->state[i]);

  return 0;

}

/* ===== end - public domain SHA512 implementation ===== */