text: /*
   *  SHA-256 implementation with hardware ESP32 support added.
   *  Uses mbedTLS software implementation for failover when concurrent
   *  SHA operations are in use.
   *
   *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
   *  Additions Copyright (C) 2016, Espressif Systems (Shanghai) PTE LTD
   *  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.
   *
   */
  
  /*
   *  The SHA-256 Secure Hash Standard was published by NIST in 2002.
   *
   *  http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
   */
  
  #if !defined(MBEDTLS_CONFIG_FILE)
  #include "mbedtls/config.h"
  #else
  #include MBEDTLS_CONFIG_FILE
  #endif
  
  #if defined(MBEDTLS_SHA256_C) && defined(MBEDTLS_SHA256_ALT)
  
  #include "mbedtls/sha256.h"
  
  #include <string.h>
  
  #if defined(MBEDTLS_SELF_TEST)
  #if defined(MBEDTLS_PLATFORM_C)
  #include "mbedtls/platform.h"
  #else
  #include <stdio.h>
  #define mbedtls_printf printf
  #endif /* MBEDTLS_PLATFORM_C */
  #endif /* MBEDTLS_SELF_TEST */
  
  #include "hwcrypto/sha.h"
  
  /* 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;
  }
  
  /*
   * 32-bit integer manipulation macros (big endian)
   */
  #ifndef GET_UINT32_BE
  #define GET_UINT32_BE(n,b,i)                            \
  do {                                                    \
      (n) = ( (uint32_t) (b)[(i)    ] << 24 )             \
          | ( (uint32_t) (b)[(i) + 1] << 16 )             \
          | ( (uint32_t) (b)[(i) + 2] <<  8 )             \
          | ( (uint32_t) (b)[(i) + 3]       );            \
  } while( 0 )
  #endif
  
  #ifndef PUT_UINT32_BE
  #define PUT_UINT32_BE(n,b,i)                            \
  do {                                                    \
      (b)[(i)    ] = (unsigned char) ( (n) >> 24 );       \
      (b)[(i) + 1] = (unsigned char) ( (n) >> 16 );       \
      (b)[(i) + 2] = (unsigned char) ( (n) >>  8 );       \
      (b)[(i) + 3] = (unsigned char) ( (n)       );       \
  } while( 0 )
  #endif
  
  void mbedtls_sha256_init( mbedtls_sha256_context *ctx )
  {
      memset( ctx, 0, sizeof( mbedtls_sha256_context ) );
  }
  
  void mbedtls_sha256_free( mbedtls_sha256_context *ctx )
  {
      if( ctx == NULL )
          return;
  
      if (ctx->mode == ESP_MBEDTLS_SHA256_HARDWARE) {
          esp_sha_unlock_engine(SHA2_256);
      }
      mbedtls_zeroize( ctx, sizeof( mbedtls_sha256_context ) );
  }
  
  void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
                             const mbedtls_sha256_context *src )
  {
      *dst = *src;
  
      if (src->mode == ESP_MBEDTLS_SHA256_HARDWARE) {
          /* Copy hardware digest state out to cloned state,
             which will become a software digest.
          */
          esp_sha_read_digest_state(SHA2_256, dst->state);
          dst->mode = ESP_MBEDTLS_SHA256_SOFTWARE;
      }
  }
  
  /*
   * SHA-256 context setup
   */
  int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 )
  {
      ctx->total[0] = 0;
      ctx->total[1] = 0;
  
      if( is224 == 0 )
      {
          /* SHA-256 */
          ctx->state[0] = 0x6A09E667;
          ctx->state[1] = 0xBB67AE85;
          ctx->state[2] = 0x3C6EF372;
          ctx->state[3] = 0xA54FF53A;
          ctx->state[4] = 0x510E527F;
          ctx->state[5] = 0x9B05688C;
          ctx->state[6] = 0x1F83D9AB;
          ctx->state[7] = 0x5BE0CD19;
      }
      else
      {
          /* SHA-224 */
          ctx->state[0] = 0xC1059ED8;
          ctx->state[1] = 0x367CD507;
          ctx->state[2] = 0x3070DD17;
          ctx->state[3] = 0xF70E5939;
          ctx->state[4] = 0xFFC00B31;
          ctx->state[5] = 0x68581511;
          ctx->state[6] = 0x64F98FA7;
          ctx->state[7] = 0xBEFA4FA4;
      }
  
      ctx->is224 = is224;
      if (ctx->mode == ESP_MBEDTLS_SHA256_HARDWARE) {
          esp_sha_unlock_engine(SHA2_256);
      }
      ctx->mode = ESP_MBEDTLS_SHA256_UNUSED;
      return 0;
  }
  
  #if !defined(MBEDTLS_DEPRECATED_REMOVED)
  void mbedtls_sha256_starts( mbedtls_sha256_context *ctx,
                              int is224 )
  {
      mbedtls_sha256_starts_ret( ctx, is224 );
  }
  #endif
  
  static const uint32_t K[] =
  {
      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,
  };
  
  #define  SHR(x,n) ((x & 0xFFFFFFFF) >> n)
  #define ROTR(x,n) (SHR(x,n) | (x << (32 - n)))
  
  #define S0(x) (ROTR(x, 7) ^ ROTR(x,18) ^  SHR(x, 3))
  #define S1(x) (ROTR(x,17) ^ ROTR(x,19) ^  SHR(x,10))
  
  #define S2(x) (ROTR(x, 2) ^ ROTR(x,13) ^ ROTR(x,22))
  #define S3(x) (ROTR(x, 6) ^ ROTR(x,11) ^ ROTR(x,25))
  
  #define F0(x,y,z) ((x & y) | (z & (x | y)))
  #define F1(x,y,z) (z ^ (x & (y ^ z)))
  
  #define R(t)                                    \
  (                                               \
      W[t] = S1(W[t -  2]) + W[t -  7] +          \
             S0(W[t - 15]) + W[t - 16]            \
  )
  
  #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;              \
  }
  
  static void mbedtls_sha256_software_process( mbedtls_sha256_context *ctx, const unsigned char data[64] );
  
  int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx, const unsigned char data[64] )
  {
      bool first_block = false;
  
      if (ctx->mode == ESP_MBEDTLS_SHA256_UNUSED) {
          /* try to use hardware for this digest */
          if (!ctx->is224 && esp_sha_try_lock_engine(SHA2_256)) {
              ctx->mode = ESP_MBEDTLS_SHA256_HARDWARE;
              first_block = true;
          } else {
              ctx->mode = ESP_MBEDTLS_SHA256_SOFTWARE;
          }
      }
  
      if (ctx->mode == ESP_MBEDTLS_SHA256_HARDWARE) {
          esp_sha_block(SHA2_256, data, first_block);
      } else {
          mbedtls_sha256_software_process(ctx, data);
      }
  
      return 0;
  }
  
  #if !defined(MBEDTLS_DEPRECATED_REMOVED)
  void mbedtls_sha256_process( mbedtls_sha256_context *ctx,
                               const unsigned char data[64] )
  {
      mbedtls_internal_sha256_process( ctx, data );
  }
  #endif
  
  static void mbedtls_sha256_software_process( mbedtls_sha256_context *ctx, const unsigned char data[64] )
  {
      uint32_t temp1, temp2, W[64];
      uint32_t A[8];
      unsigned int i;
  
      for( i = 0; i < 8; i++ )
          A[i] = ctx->state[i];
  
  #if defined(MBEDTLS_SHA256_SMALLER)
      for( i = 0; i < 64; i++ )
      {
          if( i < 16 )
              GET_UINT32_BE( W[i], data, 4 * i );
          else
              R( i );
  
          P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], W[i], K[i] );
  
          temp1 = A[7]; A[7] = A[6]; A[6] = A[5]; A[5] = A[4]; A[4] = A[3];
          A[3] = A[2]; A[2] = A[1]; A[1] = A[0]; A[0] = temp1;
      }
  #else /* MBEDTLS_SHA256_SMALLER */
      for( i = 0; i < 16; i++ )
          GET_UINT32_BE( W[i], data, 4 * i );
  
      for( i = 0; i < 16; i += 8 )
      {
          P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], W[i+0], K[i+0] );
          P( A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], W[i+1], K[i+1] );
          P( A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], W[i+2], K[i+2] );
          P( A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], W[i+3], K[i+3] );
          P( A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], W[i+4], K[i+4] );
          P( A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], W[i+5], K[i+5] );
          P( A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], W[i+6], K[i+6] );
          P( A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], W[i+7], K[i+7] );
      }
  
      for( i = 16; i < 64; i += 8 )
      {
          P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], R(i+0), K[i+0] );
          P( A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], R(i+1), K[i+1] );
          P( A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], R(i+2), K[i+2] );
          P( A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], R(i+3), K[i+3] );
          P( A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], R(i+4), K[i+4] );
          P( A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], R(i+5), K[i+5] );
          P( A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], R(i+6), K[i+6] );
          P( A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], R(i+7), K[i+7] );
      }
  #endif /* MBEDTLS_SHA256_SMALLER */
  
      for( i = 0; i < 8; i++ )
          ctx->state[i] += A[i];
  }
  
  /*
   * SHA-256 process buffer
   */
  int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx, const unsigned char *input,
                      size_t ilen )
  {
      int ret;
      size_t fill;
      uint32_t left;
  
      if( ilen == 0 )
          return 0;
  
      left = ctx->total[0] & 0x3F;
      fill = 64 - left;
  
      ctx->total[0] += (uint32_t) ilen;
      ctx->total[0] &= 0xFFFFFFFF;
  
      if( ctx->total[0] < (uint32_t) ilen )
          ctx->total[1]++;
  
      if( left && ilen >= fill )
      {
          memcpy( (void *) (ctx->buffer + left), input, fill );
  
          if ( ( ret = mbedtls_internal_sha256_process( ctx, ctx->buffer ) ) != 0 ) {
              return ret;
          }
  
          input += fill;
          ilen  -= fill;
          left = 0;
      }
  
      while( ilen >= 64 )
      {
          if ( ( ret = mbedtls_internal_sha256_process( ctx, input ) ) != 0 ) {
              return ret;
          }
  
          input += 64;
          ilen  -= 64;
      }
  
      if( ilen > 0 )
          memcpy( (void *) (ctx->buffer + left), input, ilen );
  
      return 0;
  }
  
  #if !defined(MBEDTLS_DEPRECATED_REMOVED)
  void mbedtls_sha256_update( mbedtls_sha256_context *ctx,
                              const unsigned char *input,
                              size_t ilen )
  {
      mbedtls_sha256_update_ret( ctx, input, ilen );
  }
  #endif
  
  static const unsigned char sha256_padding[64] =
  {
   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
  };
  
  /*
   * SHA-256 final digest
   */
  int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx, unsigned char output[32] )
  {
      int ret;
      uint32_t last, padn;
      uint32_t high, low;
      unsigned char msglen[8];
  
      high = ( ctx->total[0] >> 29 )
           | ( ctx->total[1] <<  3 );
      low  = ( ctx->total[0] <<  3 );
  
      PUT_UINT32_BE( high, msglen, 0 );
      PUT_UINT32_BE( low,  msglen, 4 );
  
      last = ctx->total[0] & 0x3F;
      padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
  
      if ( ( ret = mbedtls_sha256_update_ret( ctx, sha256_padding, padn ) ) != 0 ) {
          goto out;
      }
  
      if ( ( ret = mbedtls_sha256_update_ret( ctx, msglen, 8 ) ) != 0 ) {
          goto out;
      }
  
      /* if state is in hardware, read it out */
      if (ctx->mode == ESP_MBEDTLS_SHA256_HARDWARE) {
          esp_sha_read_digest_state(SHA2_256, ctx->state);
      }
  
      PUT_UINT32_BE( ctx->state[0], output,  0 );
      PUT_UINT32_BE( ctx->state[1], output,  4 );
      PUT_UINT32_BE( ctx->state[2], output,  8 );
      PUT_UINT32_BE( ctx->state[3], output, 12 );
      PUT_UINT32_BE( ctx->state[4], output, 16 );
      PUT_UINT32_BE( ctx->state[5], output, 20 );
      PUT_UINT32_BE( ctx->state[6], output, 24 );
  
      if( ctx->is224 == 0 )
          PUT_UINT32_BE( ctx->state[7], output, 28 );
  
  out:
      if (ctx->mode == ESP_MBEDTLS_SHA256_HARDWARE) {
          esp_sha_unlock_engine(SHA2_256);
          ctx->mode = ESP_MBEDTLS_SHA256_SOFTWARE;
      }
  
      return ret;
  }
  
  #if !defined(MBEDTLS_DEPRECATED_REMOVED)
  void mbedtls_sha256_finish( mbedtls_sha256_context *ctx,
                              unsigned char output[32] )
  {
      mbedtls_sha256_finish_ret( ctx, output );
  }
  #endif
  
  #endif /* MBEDTLS_SHA256_C && MBEDTLS_SHA256_ALT */
  