/*
 * FIPS 180-2 SHA-224/256/384/512 implementation
 * Last update: 02/02/2007
 * Issue date:  04/30/2005
 *
 * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "mapcache.h"
#include <string.h>
#include <stdio.h>

#define SHA256_DIGEST_SIZE ( 256 / 8)
#define SHA256_BLOCK_SIZE  ( 512 / 8)

typedef unsigned char uint8;
typedef unsigned int  uint32;
typedef unsigned long long uint64;

typedef struct {
    unsigned int tot_len;
    unsigned int len;
    unsigned char block[2 * SHA256_BLOCK_SIZE];
    uint32 h[8];
} sha256_ctx;

typedef struct {
    sha256_ctx ctx_inside;
    sha256_ctx ctx_outside;

    /* for hmac_reinit */
    sha256_ctx ctx_inside_reinit;
    sha256_ctx ctx_outside_reinit;

    unsigned char block_ipad[SHA256_BLOCK_SIZE];
    unsigned char block_opad[SHA256_BLOCK_SIZE];
} hmac_sha256_ctx;


#define SHFR(x, n)    (x >> n)
#define ROTR(x, n)   ((x >> n) | (x << ((sizeof(x) << 3) - n)))
#define ROTL(x, n)   ((x << n) | (x >> ((sizeof(x) << 3) - n)))
#define CH(x, y, z)  ((x & y) ^ (~x & z))
#define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))

#define SHA256_F1(x) (ROTR(x,  2) ^ ROTR(x, 13) ^ ROTR(x, 22))
#define SHA256_F2(x) (ROTR(x,  6) ^ ROTR(x, 11) ^ ROTR(x, 25))
#define SHA256_F3(x) (ROTR(x,  7) ^ ROTR(x, 18) ^ SHFR(x,  3))
#define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10))

#define UNPACK32(x, str)                      \
{                                             \
    *((str) + 3) = (uint8) ((x)      );       \
    *((str) + 2) = (uint8) ((x) >>  8);       \
    *((str) + 1) = (uint8) ((x) >> 16);       \
    *((str) + 0) = (uint8) ((x) >> 24);       \
}

#define PACK32(str, x)                        \
{                                             \
    *(x) =   ((uint32) *((str) + 3)      )    \
           | ((uint32) *((str) + 2) <<  8)    \
           | ((uint32) *((str) + 1) << 16)    \
           | ((uint32) *((str) + 0) << 24);   \
}

#define UNPACK64(x, str)                      \
{                                             \
    *((str) + 7) = (uint8) ((x)      );       \
    *((str) + 6) = (uint8) ((x) >>  8);       \
    *((str) + 5) = (uint8) ((x) >> 16);       \
    *((str) + 4) = (uint8) ((x) >> 24);       \
    *((str) + 3) = (uint8) ((x) >> 32);       \
    *((str) + 2) = (uint8) ((x) >> 40);       \
    *((str) + 1) = (uint8) ((x) >> 48);       \
    *((str) + 0) = (uint8) ((x) >> 56);       \
}

#define PACK64(str, x)                        \
{                                             \
    *(x) =   ((uint64) *((str) + 7)      )    \
           | ((uint64) *((str) + 6) <<  8)    \
           | ((uint64) *((str) + 5) << 16)    \
           | ((uint64) *((str) + 4) << 24)    \
           | ((uint64) *((str) + 3) << 32)    \
           | ((uint64) *((str) + 2) << 40)    \
           | ((uint64) *((str) + 1) << 48)    \
           | ((uint64) *((str) + 0) << 56);   \
}

#define SHA256_SCR(i)                         \
{                                             \
    w[i] =  SHA256_F4(w[i -  2]) + w[i -  7]  \
          + SHA256_F3(w[i - 15]) + w[i - 16]; \
}

uint32 sha256_h0[8] =
            {0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
             0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};

uint32 sha256_k[64] =
            {0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
             0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
             0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
             0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
             0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
             0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
             0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
             0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
             0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
             0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
             0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
             0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
             0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
             0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
             0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
             0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2};

void sha256_transf(sha256_ctx *ctx, const unsigned char *message,
                   unsigned int block_nb)
{
    uint32 w[64];
    uint32 wv[8];
    uint32 t1, t2;
    const unsigned char *sub_block;
    int i,j;

    for (i = 0; i < (int) block_nb; i++) {
        sub_block = message + (i << 6);

        for (j = 0; j < 16; j++) {
            PACK32(&sub_block[j << 2], &w[j]);
        }

        for (j = 16; j < 64; j++) {
            SHA256_SCR(j);
        }

        for (j = 0; j < 8; j++) {
            wv[j] = ctx->h[j];
        }

        for (j = 0; j < 64; j++) {
            t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6])
                + sha256_k[j] + w[j];
            t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]);
            wv[7] = wv[6];
            wv[6] = wv[5];
            wv[5] = wv[4];
            wv[4] = wv[3] + t1;
            wv[3] = wv[2];
            wv[2] = wv[1];
            wv[1] = wv[0];
            wv[0] = t1 + t2;
        }

        for (j = 0; j < 8; j++) {
            ctx->h[j] += wv[j];
        }
    }
}


void sha256_init(sha256_ctx *ctx)
{
    int i;
    for (i = 0; i < 8; i++) {
        ctx->h[i] = sha256_h0[i];
    }
    ctx->len = 0;
    ctx->tot_len = 0;
}

void sha256_update(sha256_ctx *ctx, const unsigned char *message,
                   unsigned int len)
{
    unsigned int block_nb;
    unsigned int new_len, rem_len, tmp_len;
    const unsigned char *shifted_message;

    tmp_len = SHA256_BLOCK_SIZE - ctx->len;
    rem_len = len < tmp_len ? len : tmp_len;

    memcpy(&ctx->block[ctx->len], message, rem_len);

    if (ctx->len + len < SHA256_BLOCK_SIZE) {
        ctx->len += len;
        return;
    }

    new_len = len - rem_len;
    block_nb = new_len / SHA256_BLOCK_SIZE;

    shifted_message = message + rem_len;

    sha256_transf(ctx, ctx->block, 1);
    sha256_transf(ctx, shifted_message, block_nb);

    rem_len = new_len % SHA256_BLOCK_SIZE;

    memcpy(ctx->block, &shifted_message[block_nb << 6],
           rem_len);

    ctx->len = rem_len;
    ctx->tot_len += (block_nb + 1) << 6;
}

void sha256_final(sha256_ctx *ctx, unsigned char *digest)
{
    unsigned int block_nb;
    unsigned int pm_len;
    unsigned int len_b;
    int i;

    block_nb = (1 + ((SHA256_BLOCK_SIZE - 9)
                     < (ctx->len % SHA256_BLOCK_SIZE)));

    len_b = (ctx->tot_len + ctx->len) << 3;
    pm_len = block_nb << 6;

    memset(ctx->block + ctx->len, 0, pm_len - ctx->len);
    ctx->block[ctx->len] = 0x80;
    UNPACK32(len_b, ctx->block + pm_len - 4);

    sha256_transf(ctx, ctx->block, block_nb);

    for (i = 0 ; i < 8; i++) {
        UNPACK32(ctx->h[i], &digest[i << 2]);
    }
}

void sha256(const unsigned char *message, unsigned int len, unsigned char *digest)
{
    sha256_ctx ctx;

    sha256_init(&ctx);
    sha256_update(&ctx, message, len);
    sha256_final(&ctx, digest);
}

void hmac_sha256_init(hmac_sha256_ctx *ctx, const unsigned char *key,
                      unsigned int key_size)
{
    unsigned int fill;
    unsigned int num;

    const unsigned char *key_used;
    unsigned char key_temp[SHA256_DIGEST_SIZE];
    int i;

    if (key_size == SHA256_BLOCK_SIZE) {
        key_used = key;
        num = SHA256_BLOCK_SIZE;
    } else {
        if (key_size > SHA256_BLOCK_SIZE){
            num = SHA256_DIGEST_SIZE;
            sha256(key, key_size, key_temp);
            key_used = key_temp;
        } else { /* key_size > SHA256_BLOCK_SIZE */
            key_used = key;
            num = key_size;
        }
        fill = SHA256_BLOCK_SIZE - num;

        memset(ctx->block_ipad + num, 0x36, fill);
        memset(ctx->block_opad + num, 0x5c, fill);
    }

    for (i = 0; i < (int) num; i++) {
        ctx->block_ipad[i] = key_used[i] ^ 0x36;
        ctx->block_opad[i] = key_used[i] ^ 0x5c;
    }

    sha256_init(&ctx->ctx_inside);
    sha256_update(&ctx->ctx_inside, ctx->block_ipad, SHA256_BLOCK_SIZE);

    sha256_init(&ctx->ctx_outside);
    sha256_update(&ctx->ctx_outside, ctx->block_opad,
                  SHA256_BLOCK_SIZE);

    /* for hmac_reinit */
    memcpy(&ctx->ctx_inside_reinit, &ctx->ctx_inside,
           sizeof(sha256_ctx));
    memcpy(&ctx->ctx_outside_reinit, &ctx->ctx_outside,
           sizeof(sha256_ctx));
}

void hmac_sha256_reinit(hmac_sha256_ctx *ctx)
{
    memcpy(&ctx->ctx_inside, &ctx->ctx_inside_reinit,
           sizeof(sha256_ctx));
    memcpy(&ctx->ctx_outside, &ctx->ctx_outside_reinit,
           sizeof(sha256_ctx));
}

void hmac_sha256_update(hmac_sha256_ctx *ctx, const unsigned char *message,
                        unsigned int message_len)
{
    sha256_update(&ctx->ctx_inside, message, message_len);
}

void hmac_sha256_final(hmac_sha256_ctx *ctx, unsigned char *mac,
                       unsigned int mac_size)
{
    unsigned char digest_inside[SHA256_DIGEST_SIZE];
    unsigned char mac_temp[SHA256_DIGEST_SIZE];

    sha256_final(&ctx->ctx_inside, digest_inside);
    sha256_update(&ctx->ctx_outside, digest_inside, SHA256_DIGEST_SIZE);
    sha256_final(&ctx->ctx_outside, mac_temp);
    memcpy(mac, mac_temp, mac_size);
}

void hmac_sha256(const unsigned char *message, unsigned int message_len,
          const unsigned char *key, unsigned int key_size,
          unsigned char *mac, unsigned mac_size)
{
    hmac_sha256_ctx ctx;

    hmac_sha256_init(&ctx, key, key_size);
    hmac_sha256_update(&ctx, message, message_len);
    hmac_sha256_final(&ctx, mac, mac_size);
}

void sha_hex_encode(unsigned char *sha, unsigned int sha_size) {
  int i = sha_size;
  while(i--) {
    char hex[3];
    sprintf(hex, "%02x", sha[i]);
    memcpy(sha+2*i,hex,2);
  }
}


#define HMAC_IPAD 0x36
#define HMAC_OPAD 0x5c
#define HMAC_BLOCKSIZE 64
#include <apr_sha1.h>

static void mxor(void *dst, const void *src, size_t len) {
    char const *s = src;
    char *d = dst;
    for (; len > 0; len--)
        *d++ ^= *s++;
    return;
}

void hmac_sha1(const char *message, unsigned int message_len,
          const unsigned char *key, unsigned int key_size,
          void *mac) {

  apr_sha1_ctx_t inner;
  apr_sha1_ctx_t outer;
  unsigned char keypad[HMAC_BLOCKSIZE];
  unsigned char inner_digest[APR_SHA1_DIGESTSIZE];
  unsigned char long_digest[APR_SHA1_DIGESTSIZE];

  /* Shorten the key down to the blocksize, anything more is useless */
  if (key_size > HMAC_BLOCKSIZE) {
    apr_sha1_ctx_t context;
    apr_sha1_init(&context);
    apr_sha1_update_binary(&context, key, key_size);
    apr_sha1_final(long_digest, &context);
    key = long_digest;
    key_size = APR_SHA1_DIGESTSIZE;
  }

  /* Prepare and mask the inner portion of the key */
  memset(keypad, HMAC_IPAD, HMAC_BLOCKSIZE);
  mxor(keypad, key, key_size);

  /* Compute the inner hash */
  apr_sha1_init(&inner);
  apr_sha1_update_binary(&inner, keypad, HMAC_BLOCKSIZE);
  apr_sha1_update(&inner, message, message_len);
  apr_sha1_final(inner_digest, &inner);

  /* Prepare and mask the outer portion of the key */
  memset(keypad, HMAC_OPAD, HMAC_BLOCKSIZE);
  mxor(keypad, key, key_size);

  /* Compute the outer hash */
  apr_sha1_init(&outer);
  apr_sha1_update_binary(&outer, keypad, HMAC_BLOCKSIZE);
  apr_sha1_update_binary(&outer, inner_digest, APR_SHA1_DIGESTSIZE);
  apr_sha1_final(mac, &outer);
}