/*
 *  FIPS-180-2 compliant SHA-384/512 implementation
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */
/*
 *  The SHA-512 Secure Hash Standard was published by NIST in 2002.
 *
 *  http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
 */

#include "sha512.h"

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

#if defined(_MSC_VER) || defined(__WATCOMC__)
  #define UL64(x) x##ui64
#else
  #define UL64(x) x##ULL
#endif

/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) {
    volatile unsigned char *p = v; while( n-- ) *p++ = 0;
}

/*
 * 64-bit integer manipulation macros (big endian)
 */
#ifndef GET_UINT64_BE
#define GET_UINT64_BE(n,b,i)                            \
{                                                       \
    (n) = ( (uint64_t) (b)[(i)    ] << 56 )       \
        | ( (uint64_t) (b)[(i) + 1] << 48 )       \
        | ( (uint64_t) (b)[(i) + 2] << 40 )       \
        | ( (uint64_t) (b)[(i) + 3] << 32 )       \
        | ( (uint64_t) (b)[(i) + 4] << 24 )       \
        | ( (uint64_t) (b)[(i) + 5] << 16 )       \
        | ( (uint64_t) (b)[(i) + 6] <<  8 )       \
        | ( (uint64_t) (b)[(i) + 7]       );      \
}
#endif /* GET_UINT64_BE */

#ifndef PUT_UINT64_BE
#define PUT_UINT64_BE(n,b,i)                            \
{                                                       \
    (b)[(i)    ] = (unsigned char) ( (n) >> 56 );       \
    (b)[(i) + 1] = (unsigned char) ( (n) >> 48 );       \
    (b)[(i) + 2] = (unsigned char) ( (n) >> 40 );       \
    (b)[(i) + 3] = (unsigned char) ( (n) >> 32 );       \
    (b)[(i) + 4] = (unsigned char) ( (n) >> 24 );       \
    (b)[(i) + 5] = (unsigned char) ( (n) >> 16 );       \
    (b)[(i) + 6] = (unsigned char) ( (n) >>  8 );       \
    (b)[(i) + 7] = (unsigned char) ( (n)       );       \
}
#endif /* PUT_UINT64_BE */

/*
 * Round constants
 */
static const uint64_t K[80] =
{
    UL64(0x428A2F98D728AE22),  UL64(0x7137449123EF65CD),
    UL64(0xB5C0FBCFEC4D3B2F),  UL64(0xE9B5DBA58189DBBC),
    UL64(0x3956C25BF348B538),  UL64(0x59F111F1B605D019),
    UL64(0x923F82A4AF194F9B),  UL64(0xAB1C5ED5DA6D8118),
    UL64(0xD807AA98A3030242),  UL64(0x12835B0145706FBE),
    UL64(0x243185BE4EE4B28C),  UL64(0x550C7DC3D5FFB4E2),
    UL64(0x72BE5D74F27B896F),  UL64(0x80DEB1FE3B1696B1),
    UL64(0x9BDC06A725C71235),  UL64(0xC19BF174CF692694),
    UL64(0xE49B69C19EF14AD2),  UL64(0xEFBE4786384F25E3),
    UL64(0x0FC19DC68B8CD5B5),  UL64(0x240CA1CC77AC9C65),
    UL64(0x2DE92C6F592B0275),  UL64(0x4A7484AA6EA6E483),
    UL64(0x5CB0A9DCBD41FBD4),  UL64(0x76F988DA831153B5),
    UL64(0x983E5152EE66DFAB),  UL64(0xA831C66D2DB43210),
    UL64(0xB00327C898FB213F),  UL64(0xBF597FC7BEEF0EE4),
    UL64(0xC6E00BF33DA88FC2),  UL64(0xD5A79147930AA725),
    UL64(0x06CA6351E003826F),  UL64(0x142929670A0E6E70),
    UL64(0x27B70A8546D22FFC),  UL64(0x2E1B21385C26C926),
    UL64(0x4D2C6DFC5AC42AED),  UL64(0x53380D139D95B3DF),
    UL64(0x650A73548BAF63DE),  UL64(0x766A0ABB3C77B2A8),
    UL64(0x81C2C92E47EDAEE6),  UL64(0x92722C851482353B),
    UL64(0xA2BFE8A14CF10364),  UL64(0xA81A664BBC423001),
    UL64(0xC24B8B70D0F89791),  UL64(0xC76C51A30654BE30),
    UL64(0xD192E819D6EF5218),  UL64(0xD69906245565A910),
    UL64(0xF40E35855771202A),  UL64(0x106AA07032BBD1B8),
    UL64(0x19A4C116B8D2D0C8),  UL64(0x1E376C085141AB53),
    UL64(0x2748774CDF8EEB99),  UL64(0x34B0BCB5E19B48A8),
    UL64(0x391C0CB3C5C95A63),  UL64(0x4ED8AA4AE3418ACB),
    UL64(0x5B9CCA4F7763E373),  UL64(0x682E6FF3D6B2B8A3),
    UL64(0x748F82EE5DEFB2FC),  UL64(0x78A5636F43172F60),
    UL64(0x84C87814A1F0AB72),  UL64(0x8CC702081A6439EC),
    UL64(0x90BEFFFA23631E28),  UL64(0xA4506CEBDE82BDE9),
    UL64(0xBEF9A3F7B2C67915),  UL64(0xC67178F2E372532B),
    UL64(0xCA273ECEEA26619C),  UL64(0xD186B8C721C0C207),
    UL64(0xEADA7DD6CDE0EB1E),  UL64(0xF57D4F7FEE6ED178),
    UL64(0x06F067AA72176FBA),  UL64(0x0A637DC5A2C898A6),
    UL64(0x113F9804BEF90DAE),  UL64(0x1B710B35131C471B),
    UL64(0x28DB77F523047D84),  UL64(0x32CAAB7B40C72493),
    UL64(0x3C9EBE0A15C9BEBC),  UL64(0x431D67C49C100D4C),
    UL64(0x4CC5D4BECB3E42B6),  UL64(0x597F299CFC657E2A),
    UL64(0x5FCB6FAB3AD6FAEC),  UL64(0x6C44198C4A475817)
};

void mbedtls_sha512_init( mbedtls_sha512_context *ctx )
{
    memset( ctx, 0, sizeof( mbedtls_sha512_context ) );
}

void mbedtls_sha512_free( mbedtls_sha512_context *ctx )
{
    if( ctx == NULL )
        return;

    mbedtls_zeroize( ctx, sizeof( mbedtls_sha512_context ) );
}

void mbedtls_sha512_clone( mbedtls_sha512_context *dst,
                           const mbedtls_sha512_context *src )
{
    *dst = *src;
}

/*
 * SHA-512 context setup
 */
void mbedtls_sha512_starts( mbedtls_sha512_context *ctx, int is384 )
{
    ctx->total[0] = 0;
    ctx->total[1] = 0;

    if( is384 == 0 )
    {
        /* SHA-512 */
        ctx->state[0] = UL64(0x6A09E667F3BCC908);
        ctx->state[1] = UL64(0xBB67AE8584CAA73B);
        ctx->state[2] = UL64(0x3C6EF372FE94F82B);
        ctx->state[3] = UL64(0xA54FF53A5F1D36F1);
        ctx->state[4] = UL64(0x510E527FADE682D1);
        ctx->state[5] = UL64(0x9B05688C2B3E6C1F);
        ctx->state[6] = UL64(0x1F83D9ABFB41BD6B);
        ctx->state[7] = UL64(0x5BE0CD19137E2179);
    }
    else
    {
        /* SHA-384 */
        ctx->state[0] = UL64(0xCBBB9D5DC1059ED8);
        ctx->state[1] = UL64(0x629A292A367CD507);
        ctx->state[2] = UL64(0x9159015A3070DD17);
        ctx->state[3] = UL64(0x152FECD8F70E5939);
        ctx->state[4] = UL64(0x67332667FFC00B31);
        ctx->state[5] = UL64(0x8EB44A8768581511);
        ctx->state[6] = UL64(0xDB0C2E0D64F98FA7);
        ctx->state[7] = UL64(0x47B5481DBEFA4FA4);
    }

    ctx->is384 = is384;
}

void mbedtls_sha512_process( mbedtls_sha512_context *ctx, const unsigned char data[SHA512_BLOCK_LENGTH] )
{
    int i;
    uint64_t temp1, temp2, W[80];
    uint64_t A, B, C, D, E, F, G, H;

#define SHR(x,n) (x >> n)
#define ROTR(x,n) (SHR(x,n) | (x << (64 - n)))

#define S0(x) (ROTR(x, 1) ^ ROTR(x, 8) ^  SHR(x, 7))
#define S1(x) (ROTR(x,19) ^ ROTR(x,61) ^  SHR(x, 6))

#define S2(x) (ROTR(x,28) ^ ROTR(x,34) ^ ROTR(x,39))
#define S3(x) (ROTR(x,14) ^ ROTR(x,18) ^ ROTR(x,41))

#define F0(x,y,z) ((x & y) | (z & (x | y)))
#define F1(x,y,z) (z ^ (x & (y ^ z)))

#define P(a,b,c,d,e,f,g,h,x,K)                  \
{                                               \
    temp1 = h + S3(e) + F1(e,f,g) + K + x;      \
    temp2 = S2(a) + F0(a,b,c);                  \
    d += temp1; h = temp1 + temp2;              \
}

    for( i = 0; i < 16; i++ )
    {
        GET_UINT64_BE( W[i], data, i << 3 );
    }

    for( ; i < 80; i++ )
    {
        W[i] = S1(W[i -  2]) + W[i -  7] +
               S0(W[i - 15]) + W[i - 16];
    }

    A = ctx->state[0];
    B = ctx->state[1];
    C = ctx->state[2];
    D = ctx->state[3];
    E = ctx->state[4];
    F = ctx->state[5];
    G = ctx->state[6];
    H = ctx->state[7];
    i = 0;

    do
    {
        P( A, B, C, D, E, F, G, H, W[i], K[i] ); i++;
        P( H, A, B, C, D, E, F, G, W[i], K[i] ); i++;
        P( G, H, A, B, C, D, E, F, W[i], K[i] ); i++;
        P( F, G, H, A, B, C, D, E, W[i], K[i] ); i++;
        P( E, F, G, H, A, B, C, D, W[i], K[i] ); i++;
        P( D, E, F, G, H, A, B, C, W[i], K[i] ); i++;
        P( C, D, E, F, G, H, A, B, W[i], K[i] ); i++;
        P( B, C, D, E, F, G, H, A, W[i], K[i] ); i++;
    }
    while( i < 80 );

    ctx->state[0] += A;
    ctx->state[1] += B;
    ctx->state[2] += C;
    ctx->state[3] += D;
    ctx->state[4] += E;
    ctx->state[5] += F;
    ctx->state[6] += G;
    ctx->state[7] += H;
}

/*
 * SHA-512 process buffer
 */
void mbedtls_sha512_update( mbedtls_sha512_context *ctx, const unsigned char *input,
                    size_t ilen )
{
    size_t fill;
    unsigned int left;

    if( ilen == 0 )
        return;

    left = (unsigned int) (ctx->total[0] & 0x7F);
    fill = 128 - left;

    ctx->total[0] += (uint64_t) ilen;

    if( ctx->total[0] < (uint64_t) ilen )
        ctx->total[1]++;

    if( left && ilen >= fill )
    {
        memcpy( (void *) (ctx->buffer + left), input, fill );
        mbedtls_sha512_process( ctx, ctx->buffer );
        input += fill;
        ilen  -= fill;
        left = 0;
    }

    while( ilen >= 128 )
    {
        mbedtls_sha512_process( ctx, input );
        input += 128;
        ilen  -= 128;
    }

    if( ilen > 0 )
        memcpy( (void *) (ctx->buffer + left), input, ilen );
}

static const unsigned char sha512_padding[SHA512_BLOCK_LENGTH] =
{
 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/*
 * SHA-512 final digest
 */
void mbedtls_sha512_finish( mbedtls_sha512_context *ctx, unsigned char* output )
{
    size_t last, padn;
    uint64_t high, low;
    unsigned char msglen[16];

    high = ( ctx->total[0] >> 61 )
         | ( ctx->total[1] <<  3 );
    low  = ( ctx->total[0] <<  3 );

    PUT_UINT64_BE( high, msglen, 0 );
    PUT_UINT64_BE( low,  msglen, 8 );

    last = (size_t)( ctx->total[0] & 0x7F );
    padn = ( last < 112 ) ? ( 112 - last ) : ( 240 - last );

    mbedtls_sha512_update( ctx, sha512_padding, padn );
    mbedtls_sha512_update( ctx, msglen, 16 );

    PUT_UINT64_BE( ctx->state[0], output,  0 );
    PUT_UINT64_BE( ctx->state[1], output,  8 );
    PUT_UINT64_BE( ctx->state[2], output, 16 );
    PUT_UINT64_BE( ctx->state[3], output, 24 );
    PUT_UINT64_BE( ctx->state[4], output, 32 );
    PUT_UINT64_BE( ctx->state[5], output, 40 );

    if( ctx->is384 == 0 )
    {
        PUT_UINT64_BE( ctx->state[6], output, 48 );
        PUT_UINT64_BE( ctx->state[7], output, 56 );
    }
}

/*
 * output = SHA-512( input buffer )
 */
void mbedtls_sha512( const unsigned char *input, size_t ilen,
             unsigned char* output, int is384 )
{
    mbedtls_sha512_context ctx;

    mbedtls_sha512_init( &ctx );
    mbedtls_sha512_starts( &ctx, is384 );
    mbedtls_sha512_update( &ctx, input, ilen );
    mbedtls_sha512_finish( &ctx, output );
    mbedtls_sha512_free( &ctx );
}

/*
* Compute HMAC_SHA384/512 using key, key length, text to hash, size of the text, output buffer and a switch for SHA384
*/
void HMAC_SHA512(const uint8_t* key, size_t key_length, const uint8_t *in, size_t n, uint8_t* out, int is384){
  int digest_length = SHA512_DIGEST_LENGTH;
  if (is384 == 1) {
    digest_length = SHA384_DIGEST_LENGTH;
  }

  uint8_t i;
  uint8_t k_ipad[SHA512_BLOCK_LENGTH]; /* inner padding - key XORd with ipad */
  uint8_t k_opad[SHA512_BLOCK_LENGTH]; /* outer padding - key XORd with opad */
  uint8_t buffer[SHA512_BLOCK_LENGTH + digest_length];

  /* start out by storing key in pads */
  memset(k_ipad, 0, sizeof(k_ipad));
  memset(k_opad, 0, sizeof(k_opad));

  if (key_length <= SHA512_BLOCK_LENGTH) {
      memcpy(k_ipad, key, key_length);
      memcpy(k_opad, key, key_length);
  }

  else {
      mbedtls_sha512(key, key_length, k_ipad, is384);
      memcpy(k_opad, k_ipad, SHA512_BLOCK_LENGTH);
  }

  /* XOR key with ipad and opad values */
  for (i = 0; i < SHA512_BLOCK_LENGTH; i++) {
      k_ipad[i] ^= HMAC_IPAD;
      k_opad[i] ^= HMAC_OPAD;
  }
  
  // perform inner SHA512
  memcpy(buffer, k_ipad, SHA512_BLOCK_LENGTH);
  memcpy(buffer + SHA512_BLOCK_LENGTH, in, n);
  mbedtls_sha512(buffer, SHA512_BLOCK_LENGTH + n, out, is384);
  
  memset(buffer, 0, SHA512_BLOCK_LENGTH + n);

  // perform outer SHA512
  memcpy(buffer, k_opad, SHA512_BLOCK_LENGTH);
  memcpy(buffer + SHA512_BLOCK_LENGTH, out, digest_length);
  mbedtls_sha512(buffer, SHA512_BLOCK_LENGTH + digest_length, out, is384);
}

/*
* Compute TOTP_HMAC_SHA384/512 using key, key length, text to hash, size of the text and a switch for SHA384
*/
uint32_t TOTP_HMAC_SHA512(const uint8_t* key, size_t key_length, const uint8_t *in, size_t n, int is384){
    int digest_length = SHA512_DIGEST_LENGTH;
    if (is384 == 1) {
      digest_length = SHA384_DIGEST_LENGTH;
    }

    // STEP 1, get the HMAC-SHA512 hash from counter and key
    uint8_t hash[digest_length];
    HMAC_SHA512(key, key_length, in, n, hash, is384);

    // STEP 2, apply dynamic truncation to obtain a 4-bytes string
    uint32_t truncated_hash = 0;
    uint8_t _offset = hash[digest_length - 1] & 0xF;
    uint8_t j;
    for (j = 0; j < 4; ++j) {
        truncated_hash <<= 8;
        truncated_hash  |= hash[_offset + j];
    }

    // STEP 3, compute the OTP value
    truncated_hash &= 0x7FFFFFFF;    //Disabled
    truncated_hash %= 1000000;

    return truncated_hash;
}