cx_sha256.c

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/*******************************************************************************
 *   Ledger Nano S - Secure firmware
 *   (c) 2022 Ledger
 *
 *  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.
 ********************************************************************************/
 
#include "app_config.h"
 
#if defined(HAVE_SHA256) || defined(HAVE_SHA224)
 
#include "cx_sha256.h"
 
#include "cx_ram.h"
#include "cx_utils.h"
#include <stdint.h>
#include <string.h>
 
#ifdef HAVE_SHA224
const cx_hash_info_t cx_sha224_info
    = {CX_SHA224,
       CX_SHA224_SIZE,
       SHA256_BLOCK_SIZE,
       sizeof(cx_sha256_t),
       (cx_err_t(*)(cx_hash_t * ctx)) cx_sha224_init_no_throw,
       (cx_err_t(*)(cx_hash_t * ctx, const uint8_t *data, size_t len)) cx_sha256_update,
       (cx_err_t(*)(cx_hash_t * ctx, uint8_t *digest)) cx_sha256_final,
       NULL,
       NULL};
#endif  // HAVE_SHA224
 
#ifdef HAVE_SHA256
const cx_hash_info_t cx_sha256_info
    = {CX_SHA256,
       CX_SHA256_SIZE,
       SHA256_BLOCK_SIZE,
       sizeof(cx_sha256_t),
       (cx_err_t(*)(cx_hash_t * ctx)) cx_sha256_init_no_throw,
       (cx_err_t(*)(cx_hash_t * ctx, const uint8_t *data, size_t len)) cx_sha256_update,
       (cx_err_t(*)(cx_hash_t * ctx, uint8_t *digest)) cx_sha256_final,
       NULL,
       NULL};
#endif  // HAVE_SHA256
 
static const uint32_t primeSqrt[] = {
    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,
};
 
#if defined(HAVE_SHA224)
static const uint32_t hzero_224[] = {0xc1059ed8,
                                     0x367cd507,
                                     0x3070dd17,
                                     0xf70e5939,
                                     0xffc00b31,
                                     0x68581511,
                                     0x64f98fa7,
                                     0xbefa4fa4};
#endif
 
static const uint32_t hzero[] = {0x6a09e667,
                                 0xbb67ae85,
                                 0x3c6ef372,
                                 0xa54ff53a,
                                 0x510e527f,
                                 0x9b05688c,
                                 0x1f83d9ab,
                                 0x5be0cd19};
 
#define sig256(x, a, b, c) (cx_rotr((x), a) ^ cx_rotr((x), b) ^ cx_shr((x), c))
#define sum256(x, a, b, c) (cx_rotr((x), a) ^ cx_rotr((x), b) ^ cx_rotr((x), c))
 
#define sigma0(x) sig256(x, 7, 18, 3)
#define sigma1(x) sig256(x, 17, 19, 10)
#define sum0(x)   sum256(x, 2, 13, 22)
#define sum1(x)   sum256(x, 6, 11, 25)
 
// #define ch(x, y, z) (((x) & (y)) ^ (~(x) & (z)))
// #define maj(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
 
#define ch(x, y, z)  (z ^ (x & (y ^ z)))
#define maj(x, y, z) ((x & y) | (z & (x | y)))
 
#if defined(HAVE_SHA224)
cx_err_t cx_sha224_init_no_throw(cx_sha256_t *hash)
{
    memset(hash, 0, sizeof(cx_sha256_t));
    hash->header.info = &cx_sha224_info;
    memmove(hash->acc, hzero_224, sizeof(hzero));
    return CX_OK;
}
#endif
 
cx_err_t cx_sha256_init_no_throw(cx_sha256_t *hash)
{
    memset(hash, 0, sizeof(cx_sha256_t));
    hash->header.info = &cx_sha256_info;
    memmove(hash->acc, hzero, sizeof(hzero));
    return CX_OK;
}
 
static void cx_sha256_block(cx_sha256_t *hash)
{
    uint32_t t1, t2;
 
    uint32_t  ACC[8];
    uint32_t *accumulator;
    uint32_t *X;
 
#define A ACC[0]
#define B ACC[1]
#define C ACC[2]
#define D ACC[3]
#define E ACC[4]
#define F ACC[5]
#define G ACC[6]
#define H ACC[7]
 
    // init
    X           = ((uint32_t *) &hash->block[0]);
    accumulator = (uint32_t *) &hash->acc[0];
    memmove(ACC, accumulator, sizeof(ACC));
 
#ifdef ARCH_LITTLE_ENDIAN
    cx_swap_buffer32(X, 16);
#endif
 
    /*
     * T1 = Sum_1_256(e) + Chg(e,f,g) + K_t_256 + Wt
     * T2 = Sum_0_256(a) + Maj(abc)
     * h = g ;
     * g = f;
     * f = e;
     * e = d + T1;
     * d = c;
     * c = b;
     * b = a;
     * a = T1 + T2;
     */
    for (int j = 0; j < 64; j++) {
        /* for j in 16 to 63, Xj <- (Sigma_1_256( Xj-2) + Xj-7 + Sigma_0_256(Xj-15)
         * + Xj-16 ). */
        if (j >= 16) {
            X[j & 0xF] = (sigma1(X[(j - 2) & 0xF]) + X[(j - 7) & 0xF] + sigma0(X[(j - 15) & 0xF])
                          + X[(j - 16) & 0xF]);
        }
 
        t1 = H + sum1(E) + ch(E, F, G) + primeSqrt[j] + X[j & 0xF];
        t2 = sum0(A) + maj(A, B, C);
        /*
        H = G ;
        G = F;
        F = E;
        E = D+t1;
        D = C;
        C = B;
        B = A;
        A = t1+t2;
        */
        memmove(&ACC[1], &ACC[0], sizeof(ACC) - sizeof(uint32_t));
        E += t1;
        A = t1 + t2;
    }
 
    //(update chaining values) (H1 , H2 , H3 , H4 ) <- (H1 + A, H2 + B, H3 + C, H4
    //+ D...)
    accumulator[0] += A;
    accumulator[1] += B;
    accumulator[2] += C;
    accumulator[3] += D;
    accumulator[4] += E;
    accumulator[5] += F;
    accumulator[6] += G;
    accumulator[7] += H;
}
 
cx_err_t cx_sha256_update(cx_sha256_t *ctx, const uint8_t *data, size_t len)
{
    size_t r;
    size_t blen;
 
    if (ctx == NULL) {
        return CX_INVALID_PARAMETER;
    }
    if (data == NULL && len != 0) {
        return CX_INVALID_PARAMETER;
    }
 
    // --- init locals ---
    blen      = ctx->blen;
    ctx->blen = 0;
 
    if (blen >= 64) {
        return CX_INVALID_PARAMETER;
    }
 
    // --- append input data and process all blocks ---
    if (blen + len >= 64) {
        r = 64 - blen;
        do {
            // if (ctx->header.counter == CX_HASH_MAX_BLOCK_COUNT) {
            //   return CX_INVALID_PARAMETER;
            // }
            memcpy(ctx->block + blen, data, r);
            cx_sha256_block(ctx);
 
            blen = 0;
            ctx->header.counter++;
            data += r;
            len -= r;
            r = 64;
        } while (len >= 64);
    }
 
    // --- remind rest data---
    memcpy(ctx->block + blen, data, len);
    blen += len;
    ctx->blen = blen;
    return CX_OK;
}
 
cx_err_t cx_sha256_final(cx_sha256_t *ctx, uint8_t *digest)
{
    uint64_t bitlen;
 
    // --- init locals ---
    uint8_t *block = ctx->block;
 
    block[ctx->blen] = 0x80;
    ctx->blen++;
 
    bitlen = (((uint64_t) ctx->header.counter) * 64UL + (uint64_t) ctx->blen - 1UL) * 8UL;
    // one more block?
    if (64 - ctx->blen < 8) {
        memset(block + ctx->blen, 0, 64 - ctx->blen);
        cx_sha256_block(ctx);
        ctx->blen = 0;
    }
    // last block!
    memset(block + ctx->blen, 0, 64 - ctx->blen);
#ifdef ARCH_LITTLE_ENDIAN
    *(uint64_t *) &block[64 - 8] = cx_swap_uint64(bitlen);
#else
    (*(uint64_t *) &block[64 - 8]) = bitlen;
#endif
    cx_sha256_block(ctx);
    // provide result
#ifdef ARCH_LITTLE_ENDIAN
    cx_swap_buffer32((uint32_t *) ctx->acc, 8);
#endif
 
#if defined(HAVE_SHA224)
    if (ctx->header.info->md_type == CX_SHA224) {
        memcpy(digest, ctx->acc, CX_SHA224_SIZE);
    }
    else
#endif
    {
        memcpy(digest, ctx->acc, CX_SHA256_SIZE);
    }
    return CX_OK;
}
 
size_t cx_hash_sha256(const uint8_t *in, size_t in_len, uint8_t *out, size_t out_len)
{
    if (out_len < CX_SHA256_SIZE) {
        return 0;
    }
    cx_sha256_init_no_throw(&G_cx.sha256);
    if (cx_sha256_update(&G_cx.sha256, in, in_len) != CX_OK) {
        return 0;
    }
    cx_sha256_final(&G_cx.sha256, out);
    explicit_bzero(&G_cx.sha256, sizeof(cx_sha256_t));
    return CX_SHA256_SIZE;
}
 
#endif  // defined(HAVE_SHA255) || defined(HAVE_SHA224)