libmicrohttpd

HTTP/1.x server C library (MHD 1.x, stable)
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sha512_256.c (28863B)


      1 /*
      2      This file is part of GNU libmicrohttpd
      3      Copyright (C) 2022-2023 Evgeny Grin (Karlson2k)
      4 
      5      GNU libmicrohttpd is free software; you can redistribute it and/or
      6      modify it under the terms of the GNU Lesser General Public
      7      License as published by the Free Software Foundation; either
      8      version 2.1 of the License, or (at your option) any later version.
      9 
     10      This library is distributed in the hope that it will be useful,
     11      but WITHOUT ANY WARRANTY; without even the implied warranty of
     12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13      Lesser General Public License for more details.
     14 
     15      You should have received a copy of the GNU Lesser General Public
     16      License along with this library.
     17      If not, see <http://www.gnu.org/licenses/>.
     18 */
     19 
     20 /**
     21  * @file microhttpd/sha512_256.c
     22  * @brief  Calculation of SHA-512/256 digest as defined in FIPS PUB 180-4 (2015)
     23  * @author Karlson2k (Evgeny Grin)
     24  */
     25 
     26 #include "sha512_256.h"
     27 
     28 #include <string.h>
     29 #ifdef HAVE_MEMORY_H
     30 #include <memory.h>
     31 #endif /* HAVE_MEMORY_H */
     32 #include "mhd_bithelpers.h"
     33 #include "mhd_assert.h"
     34 
     35 /**
     36  * Initialise structure for SHA-512/256 calculation.
     37  *
     38  * @param ctx the calculation context
     39  */
     40 void
     41 MHD_SHA512_256_init (struct Sha512_256Ctx *ctx)
     42 {
     43   /* Initial hash values, see FIPS PUB 180-4 clause 5.3.6.2 */
     44   /* Values generated by "IV Generation Function" as described in
     45    * clause 5.3.6 */
     46   ctx->H[0] = UINT64_C (0x22312194FC2BF72C);
     47   ctx->H[1] = UINT64_C (0x9F555FA3C84C64C2);
     48   ctx->H[2] = UINT64_C (0x2393B86B6F53B151);
     49   ctx->H[3] = UINT64_C (0x963877195940EABD);
     50   ctx->H[4] = UINT64_C (0x96283EE2A88EFFE3);
     51   ctx->H[5] = UINT64_C (0xBE5E1E2553863992);
     52   ctx->H[6] = UINT64_C (0x2B0199FC2C85B8AA);
     53   ctx->H[7] = UINT64_C (0x0EB72DDC81C52CA2);
     54 
     55   /* Initialise number of bytes and high part of number of bits. */
     56   ctx->count = 0;
     57   ctx->count_bits_hi = 0;
     58 }
     59 
     60 
     61 MHD_DATA_TRUNCATION_RUNTIME_CHECK_DISABLE_
     62 
     63 /**
     64  * Base of SHA-512/256 transformation.
     65  * Gets full 128 bytes block of data and updates hash values;
     66  * @param H     hash values
     67  * @param data  the data buffer with #SHA512_256_BLOCK_SIZE bytes block
     68  */
     69 static void
     70 sha512_256_transform (uint64_t H[SHA512_256_HASH_SIZE_WORDS],
     71                       const void *data)
     72 {
     73   /* Working variables,
     74      see FIPS PUB 180-4 clause 6.7, 6.4. */
     75   uint64_t a = H[0];
     76   uint64_t b = H[1];
     77   uint64_t c = H[2];
     78   uint64_t d = H[3];
     79   uint64_t e = H[4];
     80   uint64_t f = H[5];
     81   uint64_t g = H[6];
     82   uint64_t h = H[7];
     83 
     84   /* Data buffer, used as a cyclic buffer.
     85      See FIPS PUB 180-4 clause 5.2.2, 6.7, 6.4. */
     86   uint64_t W[16];
     87 
     88 #ifndef _MHD_GET_64BIT_BE_ALLOW_UNALIGNED
     89   if (0 != (((uintptr_t) data) % _MHD_UINT64_ALIGN))
     90   { /* The input data is unaligned */
     91     /* Copy the unaligned input data to the aligned buffer */
     92     memcpy (W, data, sizeof(W));
     93     /* The W[] buffer itself will be used as the source of the data,
     94      * but the data will be reloaded in correct bytes order on
     95      * the next steps */
     96     data = (const void *) W;
     97   }
     98 #endif /* _MHD_GET_64BIT_BE_ALLOW_UNALIGNED */
     99 
    100   /* 'Ch' and 'Maj' macro functions are defined with
    101      widely-used optimisation.
    102      See FIPS PUB 180-4 formulae 4.8, 4.9. */
    103 #define Ch(x,y,z)     ( (z) ^ ((x) & ((y) ^ (z))) )
    104 #define Maj(x,y,z)    ( ((x) & (y)) ^ ((z) & ((x) ^ (y))) )
    105   /* Unoptimized (original) versions: */
    106 /* #define Ch(x,y,z)  ( ( (x) & (y) ) ^ ( ~(x) & (z) ) )          */
    107 /* #define Maj(x,y,z) ( ((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)) ) */
    108 
    109   /* Four 'Sigma' macro functions.
    110      See FIPS PUB 180-4 formulae 4.10, 4.11, 4.12, 4.13. */
    111 #define SIG0(x)  \
    112   ( _MHD_ROTR64 ((x), 28) ^ _MHD_ROTR64 ((x), 34) ^ _MHD_ROTR64 ((x), 39) )
    113 #define SIG1(x)  \
    114   ( _MHD_ROTR64 ((x), 14) ^ _MHD_ROTR64 ((x), 18) ^ _MHD_ROTR64 ((x), 41) )
    115 #define sig0(x)  \
    116   ( _MHD_ROTR64 ((x), 1) ^ _MHD_ROTR64 ((x), 8) ^ ((x) >> 7) )
    117 #define sig1(x)  \
    118   ( _MHD_ROTR64 ((x), 19) ^ _MHD_ROTR64 ((x), 61) ^ ((x) >> 6) )
    119 
    120   /* One step of SHA-512/256 computation,
    121      see FIPS PUB 180-4 clause 6.4.2 step 3.
    122    * Note: this macro updates working variables in-place, without rotation.
    123    * Note: the first (vH += SIG1(vE) + Ch(vE,vF,vG) + kt + wt) equals T1 in
    124            FIPS PUB 180-4 clause 6.4.2 step 3.
    125            the second (vH += SIG0(vA) + Maj(vE,vF,vC) equals T1 + T2 in
    126            FIPS PUB 180-4 clause 6.4.2 step 3.
    127    * Note: 'wt' must be used exactly one time in this macro as it change other
    128            data as well every time when used. */
    129 #define SHA2STEP64(vA,vB,vC,vD,vE,vF,vG,vH,kt,wt) do {                  \
    130     (vD) += ((vH) += SIG1 ((vE)) + Ch ((vE),(vF),(vG)) + (kt) + (wt));  \
    131     (vH) += SIG0 ((vA)) + Maj ((vA),(vB),(vC)); } while (0)
    132 
    133   /* Get value of W(t) from input data buffer for 0 <= t <= 15,
    134      See FIPS PUB 180-4 clause 6.2.
    135      Input data must be read in big-endian bytes order,
    136      see FIPS PUB 180-4 clause 3.1.2. */
    137 #define GET_W_FROM_DATA(buf,t) \
    138   _MHD_GET_64BIT_BE (((const uint64_t*) (buf)) + (t))
    139 
    140   /* 'W' generation and assignment for 16 <= t <= 79.
    141      See FIPS PUB 180-4 clause 6.4.2.
    142      As only last 16 'W' are used in calculations, it is possible to
    143      use 16 elements array of W as a cyclic buffer.
    144    * Note: ((t-16) & 15) have same value as (t & 15) */
    145 #define Wgen(w,t) ( (w)[(t - 16) & 15] + sig1 ((w)[((t) - 2) & 15])   \
    146                     + (w)[((t) - 7) & 15] + sig0 ((w)[((t) - 15) & 15]) )
    147 
    148 #ifndef MHD_FAVOR_SMALL_CODE
    149 
    150   /* Note: instead of using K constants as array, all K values are specified
    151            individually for each step, see FIPS PUB 180-4 clause 4.2.3 for
    152            K values. */
    153   /* Note: instead of reassigning all working variables on each step,
    154            variables are rotated for each step:
    155              SHA2STEP64(a, b, c, d, e, f, g, h, K[0], data[0]);
    156              SHA2STEP64(h, a, b, c, d, e, f, g, K[1], data[1]);
    157            so current 'vD' will be used as 'vE' on next step,
    158            current 'vH' will be used as 'vA' on next step. */
    159 #if _MHD_BYTE_ORDER == _MHD_BIG_ENDIAN
    160   if ((const void *) W == data)
    161   {
    162     /* The input data is already in the cyclic data buffer W[] in correct bytes
    163        order. */
    164     SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0x428a2f98d728ae22), W[0]);
    165     SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0x7137449123ef65cd), W[1]);
    166     SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0xb5c0fbcfec4d3b2f), W[2]);
    167     SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0xe9b5dba58189dbbc), W[3]);
    168     SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x3956c25bf348b538), W[4]);
    169     SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0x59f111f1b605d019), W[5]);
    170     SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x923f82a4af194f9b), W[6]);
    171     SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0xab1c5ed5da6d8118), W[7]);
    172     SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0xd807aa98a3030242), W[8]);
    173     SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0x12835b0145706fbe), W[9]);
    174     SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0x243185be4ee4b28c), W[10]);
    175     SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0x550c7dc3d5ffb4e2), W[11]);
    176     SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x72be5d74f27b896f), W[12]);
    177     SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0x80deb1fe3b1696b1), W[13]);
    178     SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x9bdc06a725c71235), W[14]);
    179     SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0xc19bf174cf692694), W[15]);
    180   }
    181   else /* Combined with the next 'if' */
    182 #endif /* _MHD_BYTE_ORDER == _MHD_BIG_ENDIAN */
    183   if (1)
    184   {
    185     /* During first 16 steps, before making any calculations on each step,
    186        the W element is read from the input data buffer as big-endian value and
    187        stored in the array of W elements. */
    188     SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0x428a2f98d728ae22), \
    189                 W[0] = GET_W_FROM_DATA (data, 0));
    190     SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0x7137449123ef65cd), \
    191                 W[1] = GET_W_FROM_DATA (data, 1));
    192     SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0xb5c0fbcfec4d3b2f), \
    193                 W[2] = GET_W_FROM_DATA (data, 2));
    194     SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0xe9b5dba58189dbbc), \
    195                 W[3] = GET_W_FROM_DATA (data, 3));
    196     SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x3956c25bf348b538), \
    197                 W[4] = GET_W_FROM_DATA (data, 4));
    198     SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0x59f111f1b605d019), \
    199                 W[5] = GET_W_FROM_DATA (data, 5));
    200     SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x923f82a4af194f9b), \
    201                 W[6] = GET_W_FROM_DATA (data, 6));
    202     SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0xab1c5ed5da6d8118), \
    203                 W[7] = GET_W_FROM_DATA (data, 7));
    204     SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0xd807aa98a3030242), \
    205                 W[8] = GET_W_FROM_DATA (data, 8));
    206     SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0x12835b0145706fbe), \
    207                 W[9] = GET_W_FROM_DATA (data, 9));
    208     SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0x243185be4ee4b28c), \
    209                 W[10] = GET_W_FROM_DATA (data, 10));
    210     SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0x550c7dc3d5ffb4e2), \
    211                 W[11] = GET_W_FROM_DATA (data, 11));
    212     SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x72be5d74f27b896f), \
    213                 W[12] = GET_W_FROM_DATA (data, 12));
    214     SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0x80deb1fe3b1696b1), \
    215                 W[13] = GET_W_FROM_DATA (data, 13));
    216     SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x9bdc06a725c71235), \
    217                 W[14] = GET_W_FROM_DATA (data, 14));
    218     SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0xc19bf174cf692694), \
    219                 W[15] = GET_W_FROM_DATA (data, 15));
    220   }
    221 
    222   /* During last 64 steps, before making any calculations on each step,
    223      current W element is generated from other W elements of the cyclic buffer
    224      and the generated value is stored back in the cyclic buffer. */
    225   /* Note: instead of using K constants as array, all K values are specified
    226      individually for each step, see FIPS PUB 180-4 clause 4.2.3 for
    227      K values. */
    228   SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0xe49b69c19ef14ad2), \
    229               W[16 & 15] = Wgen (W,16));
    230   SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0xefbe4786384f25e3), \
    231               W[17 & 15] = Wgen (W,17));
    232   SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0x0fc19dc68b8cd5b5), \
    233               W[18 & 15] = Wgen (W,18));
    234   SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0x240ca1cc77ac9c65), \
    235               W[19 & 15] = Wgen (W,19));
    236   SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x2de92c6f592b0275), \
    237               W[20 & 15] = Wgen (W,20));
    238   SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0x4a7484aa6ea6e483), \
    239               W[21 & 15] = Wgen (W,21));
    240   SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x5cb0a9dcbd41fbd4), \
    241               W[22 & 15] = Wgen (W,22));
    242   SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0x76f988da831153b5), \
    243               W[23 & 15] = Wgen (W,23));
    244   SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0x983e5152ee66dfab), \
    245               W[24 & 15] = Wgen (W,24));
    246   SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0xa831c66d2db43210), \
    247               W[25 & 15] = Wgen (W,25));
    248   SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0xb00327c898fb213f), \
    249               W[26 & 15] = Wgen (W,26));
    250   SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0xbf597fc7beef0ee4), \
    251               W[27 & 15] = Wgen (W,27));
    252   SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0xc6e00bf33da88fc2), \
    253               W[28 & 15] = Wgen (W,28));
    254   SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0xd5a79147930aa725), \
    255               W[29 & 15] = Wgen (W,29));
    256   SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x06ca6351e003826f), \
    257               W[30 & 15] = Wgen (W,30));
    258   SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0x142929670a0e6e70), \
    259               W[31 & 15] = Wgen (W,31));
    260   SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0x27b70a8546d22ffc), \
    261               W[32 & 15] = Wgen (W,32));
    262   SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0x2e1b21385c26c926), \
    263               W[33 & 15] = Wgen (W,33));
    264   SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0x4d2c6dfc5ac42aed), \
    265               W[34 & 15] = Wgen (W,34));
    266   SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0x53380d139d95b3df), \
    267               W[35 & 15] = Wgen (W,35));
    268   SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x650a73548baf63de), \
    269               W[36 & 15] = Wgen (W,36));
    270   SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0x766a0abb3c77b2a8), \
    271               W[37 & 15] = Wgen (W,37));
    272   SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x81c2c92e47edaee6), \
    273               W[38 & 15] = Wgen (W,38));
    274   SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0x92722c851482353b), \
    275               W[39 & 15] = Wgen (W,39));
    276   SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0xa2bfe8a14cf10364), \
    277               W[40 & 15] = Wgen (W,40));
    278   SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0xa81a664bbc423001), \
    279               W[41 & 15] = Wgen (W,41));
    280   SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0xc24b8b70d0f89791), \
    281               W[42 & 15] = Wgen (W,42));
    282   SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0xc76c51a30654be30), \
    283               W[43 & 15] = Wgen (W,43));
    284   SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0xd192e819d6ef5218), \
    285               W[44 & 15] = Wgen (W,44));
    286   SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0xd69906245565a910), \
    287               W[45 & 15] = Wgen (W,45));
    288   SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0xf40e35855771202a), \
    289               W[46 & 15] = Wgen (W,46));
    290   SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0x106aa07032bbd1b8), \
    291               W[47 & 15] = Wgen (W,47));
    292   SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0x19a4c116b8d2d0c8), \
    293               W[48 & 15] = Wgen (W,48));
    294   SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0x1e376c085141ab53), \
    295               W[49 & 15] = Wgen (W,49));
    296   SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0x2748774cdf8eeb99), \
    297               W[50 & 15] = Wgen (W,50));
    298   SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0x34b0bcb5e19b48a8), \
    299               W[51 & 15] = Wgen (W,51));
    300   SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x391c0cb3c5c95a63), \
    301               W[52 & 15] = Wgen (W,52));
    302   SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0x4ed8aa4ae3418acb), \
    303               W[53 & 15] = Wgen (W,53));
    304   SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x5b9cca4f7763e373), \
    305               W[54 & 15] = Wgen (W,54));
    306   SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0x682e6ff3d6b2b8a3), \
    307               W[55 & 15] = Wgen (W,55));
    308   SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0x748f82ee5defb2fc), \
    309               W[56 & 15] = Wgen (W,56));
    310   SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0x78a5636f43172f60), \
    311               W[57 & 15] = Wgen (W,57));
    312   SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0x84c87814a1f0ab72), \
    313               W[58 & 15] = Wgen (W,58));
    314   SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0x8cc702081a6439ec), \
    315               W[59 & 15] = Wgen (W,59));
    316   SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x90befffa23631e28), \
    317               W[60 & 15] = Wgen (W,60));
    318   SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0xa4506cebde82bde9), \
    319               W[61 & 15] = Wgen (W,61));
    320   SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0xbef9a3f7b2c67915), \
    321               W[62 & 15] = Wgen (W,62));
    322   SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0xc67178f2e372532b), \
    323               W[63 & 15] = Wgen (W,63));
    324   SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0xca273eceea26619c), \
    325               W[64 & 15] = Wgen (W,64));
    326   SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0xd186b8c721c0c207), \
    327               W[65 & 15] = Wgen (W,65));
    328   SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0xeada7dd6cde0eb1e), \
    329               W[66 & 15] = Wgen (W,66));
    330   SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0xf57d4f7fee6ed178), \
    331               W[67 & 15] = Wgen (W,67));
    332   SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x06f067aa72176fba), \
    333               W[68 & 15] = Wgen (W,68));
    334   SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0x0a637dc5a2c898a6), \
    335               W[69 & 15] = Wgen (W,69));
    336   SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x113f9804bef90dae), \
    337               W[70 & 15] = Wgen (W,70));
    338   SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0x1b710b35131c471b), \
    339               W[71 & 15] = Wgen (W,71));
    340   SHA2STEP64 (a, b, c, d, e, f, g, h, UINT64_C (0x28db77f523047d84), \
    341               W[72 & 15] = Wgen (W,72));
    342   SHA2STEP64 (h, a, b, c, d, e, f, g, UINT64_C (0x32caab7b40c72493), \
    343               W[73 & 15] = Wgen (W,73));
    344   SHA2STEP64 (g, h, a, b, c, d, e, f, UINT64_C (0x3c9ebe0a15c9bebc), \
    345               W[74 & 15] = Wgen (W,74));
    346   SHA2STEP64 (f, g, h, a, b, c, d, e, UINT64_C (0x431d67c49c100d4c), \
    347               W[75 & 15] = Wgen (W,75));
    348   SHA2STEP64 (e, f, g, h, a, b, c, d, UINT64_C (0x4cc5d4becb3e42b6), \
    349               W[76 & 15] = Wgen (W,76));
    350   SHA2STEP64 (d, e, f, g, h, a, b, c, UINT64_C (0x597f299cfc657e2a), \
    351               W[77 & 15] = Wgen (W,77));
    352   SHA2STEP64 (c, d, e, f, g, h, a, b, UINT64_C (0x5fcb6fab3ad6faec), \
    353               W[78 & 15] = Wgen (W,78));
    354   SHA2STEP64 (b, c, d, e, f, g, h, a, UINT64_C (0x6c44198c4a475817), \
    355               W[79 & 15] = Wgen (W,79));
    356 #else  /* MHD_FAVOR_SMALL_CODE */
    357   if (1)
    358   {
    359     unsigned int t;
    360     /* K constants array.
    361        See FIPS PUB 180-4 clause 4.2.3 for K values. */
    362     static const uint64_t K[80] =
    363     { UINT64_C (0x428a2f98d728ae22), UINT64_C (0x7137449123ef65cd),
    364       UINT64_C (0xb5c0fbcfec4d3b2f), UINT64_C (0xe9b5dba58189dbbc),
    365       UINT64_C (0x3956c25bf348b538), UINT64_C (0x59f111f1b605d019),
    366       UINT64_C (0x923f82a4af194f9b), UINT64_C (0xab1c5ed5da6d8118),
    367       UINT64_C (0xd807aa98a3030242), UINT64_C (0x12835b0145706fbe),
    368       UINT64_C (0x243185be4ee4b28c), UINT64_C (0x550c7dc3d5ffb4e2),
    369       UINT64_C (0x72be5d74f27b896f), UINT64_C (0x80deb1fe3b1696b1),
    370       UINT64_C (0x9bdc06a725c71235), UINT64_C (0xc19bf174cf692694),
    371       UINT64_C (0xe49b69c19ef14ad2), UINT64_C (0xefbe4786384f25e3),
    372       UINT64_C (0x0fc19dc68b8cd5b5), UINT64_C (0x240ca1cc77ac9c65),
    373       UINT64_C (0x2de92c6f592b0275), UINT64_C (0x4a7484aa6ea6e483),
    374       UINT64_C (0x5cb0a9dcbd41fbd4), UINT64_C (0x76f988da831153b5),
    375       UINT64_C (0x983e5152ee66dfab), UINT64_C (0xa831c66d2db43210),
    376       UINT64_C (0xb00327c898fb213f), UINT64_C (0xbf597fc7beef0ee4),
    377       UINT64_C (0xc6e00bf33da88fc2), UINT64_C (0xd5a79147930aa725),
    378       UINT64_C (0x06ca6351e003826f), UINT64_C (0x142929670a0e6e70),
    379       UINT64_C (0x27b70a8546d22ffc), UINT64_C (0x2e1b21385c26c926),
    380       UINT64_C (0x4d2c6dfc5ac42aed), UINT64_C (0x53380d139d95b3df),
    381       UINT64_C (0x650a73548baf63de), UINT64_C (0x766a0abb3c77b2a8),
    382       UINT64_C (0x81c2c92e47edaee6), UINT64_C (0x92722c851482353b),
    383       UINT64_C (0xa2bfe8a14cf10364), UINT64_C (0xa81a664bbc423001),
    384       UINT64_C (0xc24b8b70d0f89791), UINT64_C (0xc76c51a30654be30),
    385       UINT64_C (0xd192e819d6ef5218), UINT64_C (0xd69906245565a910),
    386       UINT64_C (0xf40e35855771202a), UINT64_C (0x106aa07032bbd1b8),
    387       UINT64_C (0x19a4c116b8d2d0c8), UINT64_C (0x1e376c085141ab53),
    388       UINT64_C (0x2748774cdf8eeb99), UINT64_C (0x34b0bcb5e19b48a8),
    389       UINT64_C (0x391c0cb3c5c95a63), UINT64_C (0x4ed8aa4ae3418acb),
    390       UINT64_C (0x5b9cca4f7763e373), UINT64_C (0x682e6ff3d6b2b8a3),
    391       UINT64_C (0x748f82ee5defb2fc), UINT64_C (0x78a5636f43172f60),
    392       UINT64_C (0x84c87814a1f0ab72), UINT64_C (0x8cc702081a6439ec),
    393       UINT64_C (0x90befffa23631e28), UINT64_C (0xa4506cebde82bde9),
    394       UINT64_C (0xbef9a3f7b2c67915), UINT64_C (0xc67178f2e372532b),
    395       UINT64_C (0xca273eceea26619c), UINT64_C (0xd186b8c721c0c207),
    396       UINT64_C (0xeada7dd6cde0eb1e), UINT64_C (0xf57d4f7fee6ed178),
    397       UINT64_C (0x06f067aa72176fba), UINT64_C (0x0a637dc5a2c898a6),
    398       UINT64_C (0x113f9804bef90dae), UINT64_C (0x1b710b35131c471b),
    399       UINT64_C (0x28db77f523047d84), UINT64_C (0x32caab7b40c72493),
    400       UINT64_C (0x3c9ebe0a15c9bebc), UINT64_C (0x431d67c49c100d4c),
    401       UINT64_C (0x4cc5d4becb3e42b6), UINT64_C (0x597f299cfc657e2a),
    402       UINT64_C (0x5fcb6fab3ad6faec), UINT64_C (0x6c44198c4a475817)};
    403 
    404     /* One step of SHA-512/256 computation with working variables rotation,
    405        see FIPS PUB 180-4 clause 6.4.2 step 3.
    406      * Note: this version of macro reassign all working variable on
    407              each step. */
    408 #define SHA2STEP64RV(vA,vB,vC,vD,vE,vF,vG,vH,kt,wt) do {              \
    409   uint64_t tmp_h_ = (vH);                                             \
    410   SHA2STEP64((vA),(vB),(vC),(vD),(vE),(vF),(vG),tmp_h_,(kt),(wt));    \
    411   (vH) = (vG);                                                        \
    412   (vG) = (vF);                                                        \
    413   (vF) = (vE);                                                        \
    414   (vE) = (vD);                                                        \
    415   (vD) = (vC);                                                        \
    416   (vC) = (vB);                                                        \
    417   (vB) = (vA);                                                        \
    418   (vA) = tmp_h_;  } while (0)
    419 
    420     /* During first 16 steps, before making any calculations on each step,
    421        the W element is read from the input data buffer as big-endian value and
    422        stored in the array of W elements. */
    423     for (t = 0; t < 16; ++t)
    424     {
    425       SHA2STEP64RV (a, b, c, d, e, f, g, h, K[t], \
    426                     W[t] = GET_W_FROM_DATA (data, t));
    427     }
    428     /* During last 64 steps, before making any calculations on each step,
    429        current W element is generated from other W elements of the cyclic buffer
    430        and the generated value is stored back in the cyclic buffer. */
    431     for (t = 16; t < 80; ++t)
    432     {
    433       SHA2STEP64RV (a, b, c, d, e, f, g, h, K[t], \
    434                     W[t & 15] = Wgen (W,t));
    435     }
    436   }
    437 #endif /* MHD_FAVOR_SMALL_CODE */
    438 
    439   /* Compute and store the intermediate hash.
    440      See FIPS PUB 180-4 clause 6.4.2 step 4. */
    441   H[0] += a;
    442   H[1] += b;
    443   H[2] += c;
    444   H[3] += d;
    445   H[4] += e;
    446   H[5] += f;
    447   H[6] += g;
    448   H[7] += h;
    449 }
    450 
    451 
    452 /**
    453  * Process portion of bytes.
    454  *
    455  * @param ctx the calculation context
    456  * @param data bytes to add to hash
    457  * @param length number of bytes in @a data
    458  */
    459 void
    460 MHD_SHA512_256_update (struct Sha512_256Ctx *ctx,
    461                        const uint8_t *data,
    462                        size_t length)
    463 {
    464   unsigned int bytes_have; /**< Number of bytes in the context buffer */
    465   uint64_t count_hi; /**< The high part to be moved to another variable */
    466 
    467   mhd_assert ((data != NULL) || (length == 0));
    468 
    469 #ifndef MHD_FAVOR_SMALL_CODE
    470   if (0 == length)
    471     return; /* Shortcut, do nothing */
    472 #endif /* ! MHD_FAVOR_SMALL_CODE */
    473 
    474   /* Note: (count & (SHA512_256_BLOCK_SIZE-1))
    475            equals (count % SHA512_256_BLOCK_SIZE) for this block size. */
    476   bytes_have = (unsigned int) (ctx->count & (SHA512_256_BLOCK_SIZE - 1));
    477   ctx->count += length;
    478 #if SIZEOF_SIZE_T > 7
    479   if (length > ctx->count)
    480     ctx->count_bits_hi += 1U << 3; /* Value wrap */
    481 #endif /* SIZEOF_SIZE_T > 7 */
    482   count_hi = ctx->count >> 61;
    483   if (0 != count_hi)
    484   {
    485     ctx->count_bits_hi += count_hi;
    486     ctx->count &= UINT64_C (0x1FFFFFFFFFFFFFFF);
    487   }
    488 
    489   if (0 != bytes_have)
    490   {
    491     unsigned int bytes_left = SHA512_256_BLOCK_SIZE - bytes_have;
    492     if (length >= bytes_left)
    493     {     /* Combine new data with data in the buffer and
    494              process the full block. */
    495       memcpy (((uint8_t *) ctx->buffer) + bytes_have,
    496               data,
    497               bytes_left);
    498       data += bytes_left;
    499       length -= bytes_left;
    500       sha512_256_transform (ctx->H, ctx->buffer);
    501       bytes_have = 0;
    502     }
    503   }
    504 
    505   while (SHA512_256_BLOCK_SIZE <= length)
    506   {   /* Process any full blocks of new data directly,
    507          without copying to the buffer. */
    508     sha512_256_transform (ctx->H, data);
    509     data += SHA512_256_BLOCK_SIZE;
    510     length -= SHA512_256_BLOCK_SIZE;
    511   }
    512 
    513   if (0 != length)
    514   {   /* Copy incomplete block of new data (if any)
    515          to the buffer. */
    516     memcpy (((uint8_t *) ctx->buffer) + bytes_have, data, length);
    517   }
    518 }
    519 
    520 
    521 /**
    522  * Size of "length" insertion in bits.
    523  * See FIPS PUB 180-4 clause 5.1.2.
    524  */
    525 #define SHA512_256_SIZE_OF_LEN_ADD_BITS 128
    526 
    527 /**
    528  * Size of "length" insertion in bytes.
    529  */
    530 #define SHA512_256_SIZE_OF_LEN_ADD (SHA512_256_SIZE_OF_LEN_ADD_BITS / 8)
    531 
    532 /**
    533  * Finalise SHA-512/256 calculation, return digest.
    534  *
    535  * @param ctx the calculation context
    536  * @param[out] digest set to the hash, must be #SHA512_256_DIGEST_SIZE bytes
    537  */
    538 void
    539 MHD_SHA512_256_finish (struct Sha512_256Ctx *ctx,
    540                        uint8_t digest[SHA512_256_DIGEST_SIZE])
    541 {
    542   uint64_t num_bits;   /**< Number of processed bits */
    543   unsigned int bytes_have; /**< Number of bytes in the context buffer */
    544 
    545   /* Memorise the number of processed bits.
    546      The padding and other data added here during the postprocessing must
    547      not change the amount of hashed data. */
    548   num_bits = ctx->count << 3;
    549 
    550   /* Note: (count & (SHA512_256_BLOCK_SIZE-1))
    551            equals (count % SHA512_256_BLOCK_SIZE) for this block size. */
    552   bytes_have = (unsigned int) (ctx->count & (SHA512_256_BLOCK_SIZE - 1));
    553 
    554   /* Input data must be padded with a single bit "1", then with zeros and
    555      the finally the length of data in bits must be added as the final bytes
    556      of the last block.
    557      See FIPS PUB 180-4 clause 5.1.2. */
    558 
    559   /* Data is always processed in form of bytes (not by individual bits),
    560      therefore position of the first padding bit in byte is always
    561      predefined (0x80). */
    562   /* Buffer always have space for one byte at least (as full buffers are
    563      processed immediately). */
    564   ((uint8_t *) ctx->buffer)[bytes_have++] = 0x80;
    565 
    566   if (SHA512_256_BLOCK_SIZE - bytes_have < SHA512_256_SIZE_OF_LEN_ADD)
    567   {   /* No space in the current block to put the total length of message.
    568          Pad the current block with zeros and process it. */
    569     if (bytes_have < SHA512_256_BLOCK_SIZE)
    570       memset (((uint8_t *) ctx->buffer) + bytes_have, 0,
    571               SHA512_256_BLOCK_SIZE - bytes_have);
    572     /* Process the full block. */
    573     sha512_256_transform (ctx->H, ctx->buffer);
    574     /* Start the new block. */
    575     bytes_have = 0;
    576   }
    577 
    578   /* Pad the rest of the buffer with zeros. */
    579   memset (((uint8_t *) ctx->buffer) + bytes_have, 0,
    580           SHA512_256_BLOCK_SIZE - SHA512_256_SIZE_OF_LEN_ADD - bytes_have);
    581   /* Put high part of number of bits in processed message and then lower
    582      part of number of bits as big-endian values.
    583      See FIPS PUB 180-4 clause 5.1.2. */
    584   /* Note: the target location is predefined and buffer is always aligned */
    585   _MHD_PUT_64BIT_BE (ctx->buffer + SHA512_256_BLOCK_SIZE_WORDS - 2,
    586                      ctx->count_bits_hi);
    587   _MHD_PUT_64BIT_BE (ctx->buffer + SHA512_256_BLOCK_SIZE_WORDS - 1,
    588                      num_bits);
    589   /* Process the full final block. */
    590   sha512_256_transform (ctx->H, ctx->buffer);
    591 
    592   /* Put in BE mode the leftmost part of the hash as the final digest.
    593      See FIPS PUB 180-4 clause 6.7. */
    594 #ifndef _MHD_PUT_64BIT_BE_UNALIGNED
    595   if (1
    596 #ifndef MHD_FAVOR_SMALL_CODE
    597       && (0 != ((uintptr_t) digest) % _MHD_UINT64_ALIGN)
    598 #endif /* MHD_FAVOR_SMALL_CODE */
    599       )
    600   {
    601     /* If storing of the final result requires aligned address and
    602        the destination address is not aligned or compact code is used,
    603        store the final digest in aligned temporary buffer first, then
    604        copy it to the destination. */
    605     uint64_t alig_dgst[SHA512_256_DIGEST_SIZE_WORDS];
    606     _MHD_PUT_64BIT_BE (alig_dgst + 0, ctx->H[0]);
    607     _MHD_PUT_64BIT_BE (alig_dgst + 1, ctx->H[1]);
    608     _MHD_PUT_64BIT_BE (alig_dgst + 2, ctx->H[2]);
    609     _MHD_PUT_64BIT_BE (alig_dgst + 3, ctx->H[3]);
    610     /* Copy result to the unaligned destination address */
    611     memcpy (digest, alig_dgst, SHA512_256_DIGEST_SIZE);
    612   }
    613 #ifndef MHD_FAVOR_SMALL_CODE
    614   else /* Combined with the next 'if' */
    615 #endif /* MHD_FAVOR_SMALL_CODE */
    616 #endif /* ! _MHD_PUT_64BIT_BE_UNALIGNED */
    617 #if ! defined(MHD_FAVOR_SMALL_CODE) || defined(_MHD_PUT_64BIT_BE_UNALIGNED)
    618   if (1)
    619   {
    620     /* Use cast to (void*) here to mute compiler alignment warnings.
    621      * Compilers are not smart enough to see that alignment has been checked. */
    622     _MHD_PUT_64BIT_BE ((void *) (digest + 0 * SHA512_256_BYTES_IN_WORD), \
    623                        ctx->H[0]);
    624     _MHD_PUT_64BIT_BE ((void *) (digest + 1 * SHA512_256_BYTES_IN_WORD), \
    625                        ctx->H[1]);
    626     _MHD_PUT_64BIT_BE ((void *) (digest + 2 * SHA512_256_BYTES_IN_WORD), \
    627                        ctx->H[2]);
    628     _MHD_PUT_64BIT_BE ((void *) (digest + 3 * SHA512_256_BYTES_IN_WORD), \
    629                        ctx->H[3]);
    630   }
    631 #endif /* ! MHD_FAVOR_SMALL_CODE || _MHD_PUT_64BIT_BE_UNALIGNED */
    632 
    633   /* Erase potentially sensitive data. */
    634   memset (ctx, 0, sizeof(struct Sha512_256Ctx));
    635 }
    636 
    637 
    638 MHD_DATA_TRUNCATION_RUNTIME_CHECK_RESTORE_