| /* |
| This file is part of libmicrohttpd |
| Copyright (C) 2019-2022 Evgeny Grin (Karlson2k) |
| |
| libmicrohttpd is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| This library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with this library. |
| If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| /** |
| * @file microhttpd/sha256.c |
| * @brief Calculation of SHA-256 digest as defined in FIPS PUB 180-4 (2015) |
| * @author Karlson2k (Evgeny Grin) |
| */ |
| |
| #include "sha256.h" |
| |
| #include <string.h> |
| #ifdef HAVE_MEMORY_H |
| #include <memory.h> |
| #endif /* HAVE_MEMORY_H */ |
| #include "mhd_bithelpers.h" |
| #include "mhd_assert.h" |
| |
| /** |
| * Initialise structure for SHA256 calculation. |
| * |
| * @param ctx must be a `struct Sha256Ctx *` |
| */ |
| void |
| MHD_SHA256_init (struct Sha256Ctx *ctx) |
| { |
| /* Initial hash values, see FIPS PUB 180-4 paragraph 5.3.3 */ |
| /* First thirty-two bits of the fractional parts of the square |
| * roots of the first eight prime numbers: 2, 3, 5, 7, 11, 13, |
| * 17, 19." */ |
| ctx->H[0] = UINT32_C (0x6a09e667); |
| ctx->H[1] = UINT32_C (0xbb67ae85); |
| ctx->H[2] = UINT32_C (0x3c6ef372); |
| ctx->H[3] = UINT32_C (0xa54ff53a); |
| ctx->H[4] = UINT32_C (0x510e527f); |
| ctx->H[5] = UINT32_C (0x9b05688c); |
| ctx->H[6] = UINT32_C (0x1f83d9ab); |
| ctx->H[7] = UINT32_C (0x5be0cd19); |
| |
| /* Initialise number of bytes. */ |
| ctx->count = 0; |
| } |
| |
| |
| /** |
| * Base of SHA-256 transformation. |
| * Gets full 64 bytes block of data and updates hash values; |
| * @param H hash values |
| * @param data data, must be exactly 64 bytes long |
| */ |
| static void |
| sha256_transform (uint32_t H[SHA256_DIGEST_SIZE_WORDS], |
| const void *data) |
| { |
| /* Working variables, |
| see FIPS PUB 180-4 paragraph 6.2. */ |
| uint32_t a = H[0]; |
| uint32_t b = H[1]; |
| uint32_t c = H[2]; |
| uint32_t d = H[3]; |
| uint32_t e = H[4]; |
| uint32_t f = H[5]; |
| uint32_t g = H[6]; |
| uint32_t h = H[7]; |
| |
| /* Data buffer, used as cyclic buffer. |
| See FIPS PUB 180-4 paragraphs 5.2.1, 6.2. */ |
| uint32_t W[16]; |
| |
| #ifndef _MHD_GET_32BIT_BE_UNALIGNED |
| if (0 != (((uintptr_t) data) % _MHD_UINT32_ALIGN)) |
| { |
| /* Copy the unaligned input data to the aligned buffer */ |
| memcpy (W, data, SHA256_BLOCK_SIZE); |
| /* The W[] buffer itself will be used as the source of the data, |
| * but data will be reloaded in correct bytes order during |
| * the next steps */ |
| data = (const void *) W; |
| } |
| #endif /* _MHD_GET_32BIT_BE_UNALIGNED */ |
| |
| /* 'Ch' and 'Maj' macro functions are defined with |
| widely-used optimization. |
| See FIPS PUB 180-4 formulae 4.2, 4.3. */ |
| #define Ch(x,y,z) ( (z) ^ ((x) & ((y) ^ (z))) ) |
| #define Maj(x,y,z) ( ((x) & (y)) ^ ((z) & ((x) ^ (y))) ) |
| /* Unoptimized (original) versions: */ |
| /* #define Ch(x,y,z) ( ( (x) & (y) ) ^ ( ~(x) & (z) ) ) */ |
| /* #define Maj(x,y,z) ( ((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)) ) */ |
| |
| /* Four 'Sigma' macro functions. |
| See FIPS PUB 180-4 formulae 4.4, 4.5, 4.6, 4.7. */ |
| #define SIG0(x) (_MHD_ROTR32 ((x), 2) ^ _MHD_ROTR32 ((x), 13) ^ \ |
| _MHD_ROTR32 ((x), 22) ) |
| #define SIG1(x) (_MHD_ROTR32 ((x), 6) ^ _MHD_ROTR32 ((x), 11) ^ \ |
| _MHD_ROTR32 ((x), 25) ) |
| #define sig0(x) (_MHD_ROTR32 ((x), 7) ^ _MHD_ROTR32 ((x), 18) ^ \ |
| ((x) >> 3) ) |
| #define sig1(x) (_MHD_ROTR32 ((x), 17) ^ _MHD_ROTR32 ((x),19) ^ \ |
| ((x) >> 10) ) |
| |
| /* One step of SHA-256 computation, |
| see FIPS PUB 180-4 paragraph 6.2.2 step 3. |
| * Note: this macro updates working variables in-place, without rotation. |
| * Note: first (vH += SIG1(vE) + Ch(vE,vF,vG) + kt + wt) equals T1 in FIPS PUB 180-4 paragraph 6.2.2 step 3. |
| second (vH += SIG0(vA) + Maj(vE,vF,vC) equals T1 + T2 in FIPS PUB 180-4 paragraph 6.2.2 step 3. |
| * Note: 'wt' must be used exactly one time in this macro as it change other data as well |
| every time when used. */ |
| #define SHA2STEP32(vA,vB,vC,vD,vE,vF,vG,vH,kt,wt) do { \ |
| (vD) += ((vH) += SIG1 ((vE)) + Ch ((vE),(vF),(vG)) + (kt) + (wt)); \ |
| (vH) += SIG0 ((vA)) + Maj ((vA),(vB),(vC)); } while (0) |
| |
| /* Get value of W(t) from input data buffer, |
| See FIPS PUB 180-4 paragraph 6.2. |
| Input data must be read in big-endian bytes order, |
| see FIPS PUB 180-4 paragraph 3.1.2. */ |
| /* Use cast to (const void*) to mute compiler alignment warning, |
| * data was already aligned in previous step */ |
| #define GET_W_FROM_DATA(buf,t) \ |
| _MHD_GET_32BIT_BE ((const void*)(((const uint8_t*) (buf)) + \ |
| (t) * SHA256_BYTES_IN_WORD)) |
| |
| /* 'W' generation and assignment for 16 <= t <= 63. |
| See FIPS PUB 180-4 paragraph 6.2.2. |
| As only last 16 'W' are used in calculations, it is possible to |
| use 16 elements array of W as cyclic buffer. |
| * Note: ((t-16)&0xf) have same value as (t&0xf) */ |
| #define Wgen(w,t) ( (w)[(t - 16) & 0xf] + sig1 ((w)[((t) - 2) & 0xf]) \ |
| + (w)[((t) - 7) & 0xf] + sig0 ((w)[((t) - 15) & 0xf]) ) |
| |
| #ifndef MHD_FAVOR_SMALL_CODE |
| |
| /* Note: instead of using K constants as array, all K values are specified |
| individually for each step, see FIPS PUB 180-4 paragraph 4.2.2 for |
| K values. */ |
| /* Note: instead of reassigning all working variables on each step, |
| variables are rotated for each step: |
| SHA2STEP32(a, b, c, d, e, f, g, h, K[0], data[0]); |
| SHA2STEP32(h, a, b, c, d, e, f, g, K[1], data[1]); |
| so current 'vD' will be used as 'vE' on next step, |
| current 'vH' will be used as 'vA' on next step. */ |
| #if _MHD_BYTE_ORDER == _MHD_BIG_ENDIAN |
| if ((const void *) W == data) |
| { |
| /* The input data is already in the cyclic data buffer W[] in correct bytes |
| order. */ |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0x428a2f98), W[0]); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0x71374491), W[1]); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0xb5c0fbcf), W[2]); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0xe9b5dba5), W[3]); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0x3956c25b), W[4]); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0x59f111f1), W[5]); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0x923f82a4), W[6]); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0xab1c5ed5), W[7]); |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0xd807aa98), W[8]); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0x12835b01), W[9]); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0x243185be), W[10]); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0x550c7dc3), W[11]); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0x72be5d74), W[12]); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0x80deb1fe), W[13]); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0x9bdc06a7), W[14]); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0xc19bf174), W[15]); |
| } |
| else /* Combined with the next 'if' */ |
| #endif /* _MHD_BYTE_ORDER == _MHD_BIG_ENDIAN */ |
| if (1) |
| { |
| /* During first 16 steps, before making any calculations on each step, |
| the W element is read from input data buffer as big-endian value and |
| stored in array of W elements. */ |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0x428a2f98), W[0] = \ |
| GET_W_FROM_DATA (data, 0)); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0x71374491), W[1] = \ |
| GET_W_FROM_DATA (data, 1)); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0xb5c0fbcf), W[2] = \ |
| GET_W_FROM_DATA (data, 2)); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0xe9b5dba5), W[3] = \ |
| GET_W_FROM_DATA (data, 3)); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0x3956c25b), W[4] = \ |
| GET_W_FROM_DATA (data, 4)); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0x59f111f1), W[5] = \ |
| GET_W_FROM_DATA (data, 5)); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0x923f82a4), W[6] = \ |
| GET_W_FROM_DATA (data, 6)); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0xab1c5ed5), W[7] = \ |
| GET_W_FROM_DATA (data, 7)); |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0xd807aa98), W[8] = \ |
| GET_W_FROM_DATA (data, 8)); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0x12835b01), W[9] = \ |
| GET_W_FROM_DATA (data, 9)); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0x243185be), W[10] = \ |
| GET_W_FROM_DATA (data, 10)); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0x550c7dc3), W[11] = \ |
| GET_W_FROM_DATA (data, 11)); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0x72be5d74), W[12] = \ |
| GET_W_FROM_DATA (data, 12)); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0x80deb1fe), W[13] = \ |
| GET_W_FROM_DATA (data, 13)); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0x9bdc06a7), W[14] = \ |
| GET_W_FROM_DATA (data, 14)); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0xc19bf174), W[15] = \ |
| GET_W_FROM_DATA (data, 15)); |
| } |
| |
| /* During last 48 steps, before making any calculations on each step, |
| current W element is generated from other W elements of the cyclic buffer |
| and the generated value is stored back in the cyclic buffer. */ |
| /* Note: instead of using K constants as array, all K values are specified |
| individually for each step, see FIPS PUB 180-4 paragraph 4.2.2 for K values. */ |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0xe49b69c1), W[16 & 0xf] = \ |
| Wgen (W,16)); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0xefbe4786), W[17 & 0xf] = \ |
| Wgen (W,17)); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0x0fc19dc6), W[18 & 0xf] = \ |
| Wgen (W,18)); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0x240ca1cc), W[19 & 0xf] = \ |
| Wgen (W,19)); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0x2de92c6f), W[20 & 0xf] = \ |
| Wgen (W,20)); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0x4a7484aa), W[21 & 0xf] = \ |
| Wgen (W,21)); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0x5cb0a9dc), W[22 & 0xf] = \ |
| Wgen (W,22)); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0x76f988da), W[23 & 0xf] = \ |
| Wgen (W,23)); |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0x983e5152), W[24 & 0xf] = \ |
| Wgen (W,24)); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0xa831c66d), W[25 & 0xf] = \ |
| Wgen (W,25)); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0xb00327c8), W[26 & 0xf] = \ |
| Wgen (W,26)); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0xbf597fc7), W[27 & 0xf] = \ |
| Wgen (W,27)); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0xc6e00bf3), W[28 & 0xf] = \ |
| Wgen (W,28)); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0xd5a79147), W[29 & 0xf] = \ |
| Wgen (W,29)); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0x06ca6351), W[30 & 0xf] = \ |
| Wgen (W,30)); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0x14292967), W[31 & 0xf] = \ |
| Wgen (W,31)); |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0x27b70a85), W[32 & 0xf] = \ |
| Wgen (W,32)); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0x2e1b2138), W[33 & 0xf] = \ |
| Wgen (W,33)); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0x4d2c6dfc), W[34 & 0xf] = \ |
| Wgen (W,34)); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0x53380d13), W[35 & 0xf] = \ |
| Wgen (W,35)); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0x650a7354), W[36 & 0xf] = \ |
| Wgen (W,36)); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0x766a0abb), W[37 & 0xf] = \ |
| Wgen (W,37)); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0x81c2c92e), W[38 & 0xf] = \ |
| Wgen (W,38)); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0x92722c85), W[39 & 0xf] = \ |
| Wgen (W,39)); |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0xa2bfe8a1), W[40 & 0xf] = \ |
| Wgen (W,40)); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0xa81a664b), W[41 & 0xf] = \ |
| Wgen (W,41)); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0xc24b8b70), W[42 & 0xf] = \ |
| Wgen (W,42)); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0xc76c51a3), W[43 & 0xf] = \ |
| Wgen (W,43)); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0xd192e819), W[44 & 0xf] = \ |
| Wgen (W,44)); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0xd6990624), W[45 & 0xf] = \ |
| Wgen (W,45)); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0xf40e3585), W[46 & 0xf] = \ |
| Wgen (W,46)); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0x106aa070), W[47 & 0xf] = \ |
| Wgen (W,47)); |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0x19a4c116), W[48 & 0xf] = \ |
| Wgen (W,48)); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0x1e376c08), W[49 & 0xf] = \ |
| Wgen (W,49)); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0x2748774c), W[50 & 0xf] = \ |
| Wgen (W,50)); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0x34b0bcb5), W[51 & 0xf] = \ |
| Wgen (W,51)); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0x391c0cb3), W[52 & 0xf] = \ |
| Wgen (W,52)); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0x4ed8aa4a), W[53 & 0xf] = \ |
| Wgen (W,53)); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0x5b9cca4f), W[54 & 0xf] = \ |
| Wgen (W,54)); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0x682e6ff3), W[55 & 0xf] = \ |
| Wgen (W,55)); |
| SHA2STEP32 (a, b, c, d, e, f, g, h, UINT32_C (0x748f82ee), W[56 & 0xf] = \ |
| Wgen (W,56)); |
| SHA2STEP32 (h, a, b, c, d, e, f, g, UINT32_C (0x78a5636f), W[57 & 0xf] = \ |
| Wgen (W,57)); |
| SHA2STEP32 (g, h, a, b, c, d, e, f, UINT32_C (0x84c87814), W[58 & 0xf] = \ |
| Wgen (W,58)); |
| SHA2STEP32 (f, g, h, a, b, c, d, e, UINT32_C (0x8cc70208), W[59 & 0xf] = \ |
| Wgen (W,59)); |
| SHA2STEP32 (e, f, g, h, a, b, c, d, UINT32_C (0x90befffa), W[60 & 0xf] = \ |
| Wgen (W,60)); |
| SHA2STEP32 (d, e, f, g, h, a, b, c, UINT32_C (0xa4506ceb), W[61 & 0xf] = \ |
| Wgen (W,61)); |
| SHA2STEP32 (c, d, e, f, g, h, a, b, UINT32_C (0xbef9a3f7), W[62 & 0xf] = \ |
| Wgen (W,62)); |
| SHA2STEP32 (b, c, d, e, f, g, h, a, UINT32_C (0xc67178f2), W[63 & 0xf] = \ |
| Wgen (W,63)); |
| #else /* ! MHD_FAVOR_SMALL_CODE */ |
| if (1) |
| { |
| unsigned int t; |
| /* K constants array. |
| See FIPS PUB 180-4 paragraph 4.2.2 for K values. */ |
| static const uint32_t K[80] = |
| { UINT32_C (0x428a2f98), UINT32_C (0x71374491), UINT32_C (0xb5c0fbcf), |
| UINT32_C (0xe9b5dba5), UINT32_C (0x3956c25b), UINT32_C (0x59f111f1), |
| UINT32_C (0x923f82a4), UINT32_C (0xab1c5ed5), UINT32_C (0xd807aa98), |
| UINT32_C (0x12835b01), UINT32_C (0x243185be), UINT32_C (0x550c7dc3), |
| UINT32_C (0x72be5d74), UINT32_C (0x80deb1fe), UINT32_C (0x9bdc06a7), |
| UINT32_C (0xc19bf174), UINT32_C (0xe49b69c1), UINT32_C (0xefbe4786), |
| UINT32_C (0x0fc19dc6), UINT32_C (0x240ca1cc), UINT32_C (0x2de92c6f), |
| UINT32_C (0x4a7484aa), UINT32_C (0x5cb0a9dc), UINT32_C (0x76f988da), |
| UINT32_C (0x983e5152), UINT32_C (0xa831c66d), UINT32_C (0xb00327c8), |
| UINT32_C (0xbf597fc7), UINT32_C (0xc6e00bf3), UINT32_C (0xd5a79147), |
| UINT32_C (0x06ca6351), UINT32_C (0x14292967), UINT32_C (0x27b70a85), |
| UINT32_C (0x2e1b2138), UINT32_C (0x4d2c6dfc), UINT32_C (0x53380d13), |
| UINT32_C (0x650a7354), UINT32_C (0x766a0abb), UINT32_C (0x81c2c92e), |
| UINT32_C (0x92722c85), UINT32_C (0xa2bfe8a1), UINT32_C (0xa81a664b), |
| UINT32_C (0xc24b8b70), UINT32_C (0xc76c51a3), UINT32_C (0xd192e819), |
| UINT32_C (0xd6990624), UINT32_C (0xf40e3585), UINT32_C (0x106aa070), |
| UINT32_C (0x19a4c116), UINT32_C (0x1e376c08), UINT32_C (0x2748774c), |
| UINT32_C (0x34b0bcb5), UINT32_C (0x391c0cb3), UINT32_C (0x4ed8aa4a), |
| UINT32_C (0x5b9cca4f), UINT32_C (0x682e6ff3), UINT32_C (0x748f82ee), |
| UINT32_C (0x78a5636f), UINT32_C (0x84c87814), UINT32_C (0x8cc70208), |
| UINT32_C (0x90befffa), UINT32_C (0xa4506ceb), UINT32_C (0xbef9a3f7), |
| UINT32_C (0xc67178f2) }; |
| /* One step of SHA-256 computation with working variables rotation, |
| see FIPS PUB 180-4 paragraph 6.2.2 step 3. |
| * Note: this version of macro reassign all working variable on |
| each step. */ |
| #define SHA2STEP32RV(vA,vB,vC,vD,vE,vF,vG,vH,kt,wt) do { \ |
| uint32_t tmp_h_ = (vH); \ |
| SHA2STEP32((vA),(vB),(vC),(vD),(vE),(vF),(vG),tmp_h_,(kt),(wt)); \ |
| (vH) = (vG); \ |
| (vG) = (vF); \ |
| (vF) = (vE); \ |
| (vE) = (vD); \ |
| (vD) = (vC); \ |
| (vC) = (vB); \ |
| (vB) = (vA); \ |
| (vA) = tmp_h_; } while (0) |
| |
| /* During first 16 steps, before making any calculations on each step, |
| the W element is read from input data buffer as big-endian value and |
| stored in array of W elements. */ |
| for (t = 0; t < 16; ++t) |
| { |
| SHA2STEP32RV (a, b, c, d, e, f, g, h, K[t], \ |
| W[t] = GET_W_FROM_DATA (data, t)); |
| } |
| |
| /* During last 48 steps, before making any calculations on each step, |
| current W element is generated from other W elements of the cyclic buffer |
| and the generated value is stored back in the cyclic buffer. */ |
| for (t = 16; t < 64; ++t) |
| { |
| SHA2STEP32RV (a, b, c, d, e, f, g, h, K[t], W[t & 15] = Wgen (W,t)); |
| } |
| } |
| #endif /* ! MHD_FAVOR_SMALL_CODE */ |
| |
| |
| /* Compute intermediate hash. |
| See FIPS PUB 180-4 paragraph 6.2.2 step 4. */ |
| H[0] += a; |
| H[1] += b; |
| H[2] += c; |
| H[3] += d; |
| H[4] += e; |
| H[5] += f; |
| H[6] += g; |
| H[7] += h; |
| } |
| |
| |
| /** |
| * Process portion of bytes. |
| * |
| * @param ctx_ must be a `struct Sha256Ctx *` |
| * @param data bytes to add to hash |
| * @param length number of bytes in @a data |
| */ |
| void |
| MHD_SHA256_update (struct Sha256Ctx *ctx, |
| const uint8_t *data, |
| size_t length) |
| { |
| unsigned bytes_have; /**< Number of bytes in buffer */ |
| |
| mhd_assert ((data != NULL) || (length == 0)); |
| |
| #ifndef MHD_FAVOR_SMALL_CODE |
| if (0 == length) |
| return; /* Shortcut, do nothing */ |
| #endif /* MHD_FAVOR_SMALL_CODE */ |
| |
| /* Note: (count & (SHA256_BLOCK_SIZE-1)) |
| equals (count % SHA256_BLOCK_SIZE) for this block size. */ |
| bytes_have = (unsigned) (ctx->count & (SHA256_BLOCK_SIZE - 1)); |
| ctx->count += length; |
| |
| if (0 != bytes_have) |
| { |
| unsigned bytes_left = SHA256_BLOCK_SIZE - bytes_have; |
| if (length >= bytes_left) |
| { /* Combine new data with data in the buffer and |
| process full block. */ |
| memcpy (((uint8_t *) ctx->buffer) + bytes_have, |
| data, |
| bytes_left); |
| data += bytes_left; |
| length -= bytes_left; |
| sha256_transform (ctx->H, ctx->buffer); |
| bytes_have = 0; |
| } |
| } |
| |
| while (SHA256_BLOCK_SIZE <= length) |
| { /* Process any full blocks of new data directly, |
| without copying to the buffer. */ |
| sha256_transform (ctx->H, data); |
| data += SHA256_BLOCK_SIZE; |
| length -= SHA256_BLOCK_SIZE; |
| } |
| |
| if (0 != length) |
| { /* Copy incomplete block of new data (if any) |
| to the buffer. */ |
| memcpy (((uint8_t *) ctx->buffer) + bytes_have, data, length); |
| } |
| } |
| |
| |
| /** |
| * Size of "length" padding addition in bytes. |
| * See FIPS PUB 180-4 paragraph 5.1.1. |
| */ |
| #define SHA256_SIZE_OF_LEN_ADD (64 / 8) |
| |
| /** |
| * Finalise SHA256 calculation, return digest. |
| * |
| * @param ctx_ must be a `struct Sha256Ctx *` |
| * @param[out] digest set to the hash, must be #SHA256_DIGEST_SIZE bytes |
| */ |
| void |
| MHD_SHA256_finish (struct Sha256Ctx *ctx, |
| uint8_t digest[SHA256_DIGEST_SIZE]) |
| { |
| uint64_t num_bits; /**< Number of processed bits */ |
| unsigned bytes_have; /**< Number of bytes in buffer */ |
| |
| num_bits = ctx->count << 3; |
| /* Note: (count & (SHA256_BLOCK_SIZE-1)) |
| equal (count % SHA256_BLOCK_SIZE) for this block size. */ |
| bytes_have = (unsigned) (ctx->count & (SHA256_BLOCK_SIZE - 1)); |
| |
| /* Input data must be padded with a single bit "1", then with zeros and |
| the finally the length of data in bits must be added as the final bytes |
| of the last block. |
| See FIPS PUB 180-4 paragraph 5.1.1. */ |
| |
| /* Data is always processed in form of bytes (not by individual bits), |
| therefore position of first padding bit in byte is always |
| predefined (0x80). */ |
| /* Buffer always have space at least for one byte (as full buffers are |
| processed immediately). */ |
| ((uint8_t *) ctx->buffer)[bytes_have++] = 0x80; |
| |
| if (SHA256_BLOCK_SIZE - bytes_have < SHA256_SIZE_OF_LEN_ADD) |
| { /* No space in current block to put total length of message. |
| Pad current block with zeros and process it. */ |
| if (bytes_have < SHA256_BLOCK_SIZE) |
| memset (((uint8_t *) ctx->buffer) + bytes_have, 0, |
| SHA256_BLOCK_SIZE - bytes_have); |
| /* Process full block. */ |
| sha256_transform (ctx->H, ctx->buffer); |
| /* Start new block. */ |
| bytes_have = 0; |
| } |
| |
| /* Pad the rest of the buffer with zeros. */ |
| memset (((uint8_t *) ctx->buffer) + bytes_have, 0, |
| SHA256_BLOCK_SIZE - SHA256_SIZE_OF_LEN_ADD - bytes_have); |
| /* Put the number of bits in processed message as big-endian value. */ |
| _MHD_PUT_64BIT_BE_SAFE (ctx->buffer + SHA256_BLOCK_SIZE_WORDS - 2, num_bits); |
| /* Process full final block. */ |
| sha256_transform (ctx->H, ctx->buffer); |
| |
| /* Put final hash/digest in BE mode */ |
| #ifndef _MHD_PUT_32BIT_BE_UNALIGNED |
| if (1 |
| #ifndef MHD_FAVOR_SMALL_CODE |
| && (0 != ((uintptr_t) digest) % _MHD_UINT32_ALIGN) |
| #endif /* MHD_FAVOR_SMALL_CODE */ |
| ) |
| { |
| /* If storing of the final result requires aligned address and |
| the destination address is not aligned or compact code is used, |
| store the final digest in aligned temporary buffer first, then |
| copy it to the destination. */ |
| uint32_t alig_dgst[SHA256_DIGEST_SIZE_WORDS]; |
| _MHD_PUT_32BIT_BE (alig_dgst + 0, ctx->H[0]); |
| _MHD_PUT_32BIT_BE (alig_dgst + 1, ctx->H[1]); |
| _MHD_PUT_32BIT_BE (alig_dgst + 2, ctx->H[2]); |
| _MHD_PUT_32BIT_BE (alig_dgst + 3, ctx->H[3]); |
| _MHD_PUT_32BIT_BE (alig_dgst + 4, ctx->H[4]); |
| _MHD_PUT_32BIT_BE (alig_dgst + 5, ctx->H[5]); |
| _MHD_PUT_32BIT_BE (alig_dgst + 6, ctx->H[6]); |
| _MHD_PUT_32BIT_BE (alig_dgst + 7, ctx->H[7]); |
| /* Copy result to unaligned destination address */ |
| memcpy (digest, alig_dgst, SHA256_DIGEST_SIZE); |
| } |
| #ifndef MHD_FAVOR_SMALL_CODE |
| else /* Combined with the next 'if' */ |
| #endif /* MHD_FAVOR_SMALL_CODE */ |
| #endif /* ! _MHD_PUT_32BIT_BE_UNALIGNED */ |
| #if ! defined(MHD_FAVOR_SMALL_CODE) || defined(_MHD_PUT_32BIT_BE_UNALIGNED) |
| if (1) |
| { |
| /* Use cast to (void*) here to mute compiler alignment warnings. |
| * Compilers are not smart enough to see that alignment has been checked. */ |
| _MHD_PUT_32BIT_BE ((void *) (digest + 0 * SHA256_BYTES_IN_WORD), ctx->H[0]); |
| _MHD_PUT_32BIT_BE ((void *) (digest + 1 * SHA256_BYTES_IN_WORD), ctx->H[1]); |
| _MHD_PUT_32BIT_BE ((void *) (digest + 2 * SHA256_BYTES_IN_WORD), ctx->H[2]); |
| _MHD_PUT_32BIT_BE ((void *) (digest + 3 * SHA256_BYTES_IN_WORD), ctx->H[3]); |
| _MHD_PUT_32BIT_BE ((void *) (digest + 4 * SHA256_BYTES_IN_WORD), ctx->H[4]); |
| _MHD_PUT_32BIT_BE ((void *) (digest + 5 * SHA256_BYTES_IN_WORD), ctx->H[5]); |
| _MHD_PUT_32BIT_BE ((void *) (digest + 6 * SHA256_BYTES_IN_WORD), ctx->H[6]); |
| _MHD_PUT_32BIT_BE ((void *) (digest + 7 * SHA256_BYTES_IN_WORD), ctx->H[7]); |
| } |
| #endif /* ! MHD_FAVOR_SMALL_CODE || _MHD_PUT_32BIT_BE_UNALIGNED */ |
| |
| /* Erase potentially sensitive data. */ |
| memset (ctx, 0, sizeof(struct Sha256Ctx)); |
| } |