library/sha256.c - security/mbedtls - Rivoreo Source Code Repositories

 /*
  *  FIPS-180-2 compliant SHA-256 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-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)

 #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>
 #include <stdlib.h>
 #define mbedtls_printf printf
 #define mbedtls_calloc    calloc
 #define mbedtls_free       free
 #endif /* MBEDTLS_PLATFORM_C */
 #endif /* MBEDTLS_SELF_TEST */

 #if !defined(MBEDTLS_SHA256_ALT)

 /* 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;

     mbedtls_zeroize( ctx, sizeof( mbedtls_sha256_context ) );
 }

 void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
                            const mbedtls_sha256_context *src )
 {
     *dst = *src;
 }

 /*
  * 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;

     return( 0 );
 }

 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
 void mbedtls_sha256_starts( mbedtls_sha256_context *ctx,
                             int is224 )
 {
     mbedtls_sha256_starts_ret( ctx, is224 );
 }
 #endif

 #if !defined(MBEDTLS_SHA256_PROCESS_ALT)
 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;              \
 }

 int mbedtls_internal_sha256_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];

     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
 #endif /* !MBEDTLS_SHA256_PROCESS_ALT */

 /*
  * 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

 /*
  * SHA-256 final digest
  */
 int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
                                unsigned char output[32] )
 {
     int ret;
     uint32_t used;
     uint32_t high, low;

     /*
      * Add padding: 0x80 then 0x00 until 8 bytes remain for the length
      */
     used = ctx->total[0] & 0x3F;

     ctx->buffer[used++] = 0x80;

     if( used <= 56 )
     {
         /* Enough room for padding + length in current block */
         memset( ctx->buffer + used, 0, 56 - used );
     }
     else
     {
         /* We'll need an extra block */
         memset( ctx->buffer + used, 0, 64 - used );

         if( ( ret = mbedtls_internal_sha256_process( ctx, ctx->buffer ) ) != 0 )
             return( ret );

         memset( ctx->buffer, 0, 56 );
     }

     /*
      * Add message length
      */
     high = ( ctx->total[0] >> 29 )
          | ( ctx->total[1] <<  3 );
     low  = ( ctx->total[0] <<  3 );

     PUT_UINT32_BE( high, ctx->buffer, 56 );
     PUT_UINT32_BE( low,  ctx->buffer, 60 );

     if( ( ret = mbedtls_internal_sha256_process( ctx, ctx->buffer ) ) != 0 )
         return( ret );

     /*
      * Output final 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 );

     return( 0 );
 }

 #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_ALT */

 /*
  * output = SHA-256( input buffer )
  */
 int mbedtls_sha256_ret( const unsigned char *input,
                         size_t ilen,
                         unsigned char output[32],
                         int is224 )
 {
     int ret;
     mbedtls_sha256_context ctx;

     mbedtls_sha256_init( &ctx );

     if( ( ret = mbedtls_sha256_starts_ret( &ctx, is224 ) ) != 0 )
         goto exit;

     if( ( ret = mbedtls_sha256_update_ret( &ctx, input, ilen ) ) != 0 )
         goto exit;

     if( ( ret = mbedtls_sha256_finish_ret( &ctx, output ) ) != 0 )
         goto exit;

 exit:
     mbedtls_sha256_free( &ctx );

     return( ret );
 }

 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
 void mbedtls_sha256( const unsigned char *input,
                      size_t ilen,
                      unsigned char output[32],
                      int is224 )
 {
     mbedtls_sha256_ret( input, ilen, output, is224 );
 }
 #endif

 #if defined(MBEDTLS_SELF_TEST)
 /*
  * FIPS-180-2 test vectors
  */
 static const unsigned char sha256_test_buf[3][57] =
 {
     { "abc" },
     { "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq" },
     { "" }
 };

 static const size_t sha256_test_buflen[3] =
 {
     3, 56, 1000
 };

 static const unsigned char sha256_test_sum[6][32] =
 {
     /*
      * SHA-224 test vectors
      */
     { 0x23, 0x09, 0x7D, 0x22, 0x34, 0x05, 0xD8, 0x22,
       0x86, 0x42, 0xA4, 0x77, 0xBD, 0xA2, 0x55, 0xB3,
       0x2A, 0xAD, 0xBC, 0xE4, 0xBD, 0xA0, 0xB3, 0xF7,
       0xE3, 0x6C, 0x9D, 0xA7 },
     { 0x75, 0x38, 0x8B, 0x16, 0x51, 0x27, 0x76, 0xCC,
       0x5D, 0xBA, 0x5D, 0xA1, 0xFD, 0x89, 0x01, 0x50,
       0xB0, 0xC6, 0x45, 0x5C, 0xB4, 0xF5, 0x8B, 0x19,
       0x52, 0x52, 0x25, 0x25 },
     { 0x20, 0x79, 0x46, 0x55, 0x98, 0x0C, 0x91, 0xD8,
       0xBB, 0xB4, 0xC1, 0xEA, 0x97, 0x61, 0x8A, 0x4B,
       0xF0, 0x3F, 0x42, 0x58, 0x19, 0x48, 0xB2, 0xEE,
       0x4E, 0xE7, 0xAD, 0x67 },

     /*
      * SHA-256 test vectors
      */
     { 0xBA, 0x78, 0x16, 0xBF, 0x8F, 0x01, 0xCF, 0xEA,
       0x41, 0x41, 0x40, 0xDE, 0x5D, 0xAE, 0x22, 0x23,
       0xB0, 0x03, 0x61, 0xA3, 0x96, 0x17, 0x7A, 0x9C,
       0xB4, 0x10, 0xFF, 0x61, 0xF2, 0x00, 0x15, 0xAD },
     { 0x24, 0x8D, 0x6A, 0x61, 0xD2, 0x06, 0x38, 0xB8,
       0xE5, 0xC0, 0x26, 0x93, 0x0C, 0x3E, 0x60, 0x39,
       0xA3, 0x3C, 0xE4, 0x59, 0x64, 0xFF, 0x21, 0x67,
       0xF6, 0xEC, 0xED, 0xD4, 0x19, 0xDB, 0x06, 0xC1 },
     { 0xCD, 0xC7, 0x6E, 0x5C, 0x99, 0x14, 0xFB, 0x92,
       0x81, 0xA1, 0xC7, 0xE2, 0x84, 0xD7, 0x3E, 0x67,
       0xF1, 0x80, 0x9A, 0x48, 0xA4, 0x97, 0x20, 0x0E,
       0x04, 0x6D, 0x39, 0xCC, 0xC7, 0x11, 0x2C, 0xD0 }
 };

 /*
  * Checkup routine
  */
 int mbedtls_sha256_self_test( int verbose )
 {
     int i, j, k, buflen, ret = 0;
     unsigned char *buf;
     unsigned char sha256sum[32];
     mbedtls_sha256_context ctx;

     buf = mbedtls_calloc( 1024, sizeof(unsigned char) );
     if( NULL == buf )
     {
         if( verbose != 0 )
             mbedtls_printf( "Buffer allocation failed\n" );

         return( 1 );
     }

     mbedtls_sha256_init( &ctx );

     for( i = 0; i < 6; i++ )
     {
         j = i % 3;
         k = i < 3;

         if( verbose != 0 )
             mbedtls_printf( "  SHA-%d test #%d: ", 256 - k * 32, j + 1 );

         if( ( ret = mbedtls_sha256_starts_ret( &ctx, k ) ) != 0 )
             goto fail;

         if( j == 2 )
         {
             memset( buf, 'a', buflen = 1000 );

             for( j = 0; j < 1000; j++ )
             {
                 ret = mbedtls_sha256_update_ret( &ctx, buf, buflen );
                 if( ret != 0 )
                     goto fail;
             }

         }
         else
         {
             ret = mbedtls_sha256_update_ret( &ctx, sha256_test_buf[j],
                                              sha256_test_buflen[j] );
             if( ret != 0 )
                  goto fail;
         }

         if( ( ret = mbedtls_sha256_finish_ret( &ctx, sha256sum ) ) != 0 )
             goto fail;


         if( memcmp( sha256sum, sha256_test_sum[i], 32 - k * 4 ) != 0 )
         {
             ret = 1;
             goto fail;
         }

         if( verbose != 0 )
             mbedtls_printf( "passed\n" );
     }

     if( verbose != 0 )
         mbedtls_printf( "\n" );

     goto exit;

 fail:
     if( verbose != 0 )
         mbedtls_printf( "failed\n" );

 exit:
     mbedtls_sha256_free( &ctx );
     mbedtls_free( buf );

     return( ret );
 }

 #endif /* MBEDTLS_SELF_TEST */

 #endif /* MBEDTLS_SHA256_C */
	/*
	* FIPS-180-2 compliant SHA-256 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-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)

	#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>
	#include <stdlib.h>
	#define mbedtls_printf printf
	#define mbedtls_calloc calloc
	#define mbedtls_free free
	#endif /* MBEDTLS_PLATFORM_C */
	#endif /* MBEDTLS_SELF_TEST */

	#if !defined(MBEDTLS_SHA256_ALT)

	/* 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;

	mbedtls_zeroize( ctx, sizeof( mbedtls_sha256_context ) );
	}

	void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
	const mbedtls_sha256_context *src )
	{
	dst = src;
	}

	/*
	* 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;

	return( 0 );
	}

	#if !defined(MBEDTLS_DEPRECATED_REMOVED)
	void mbedtls_sha256_starts( mbedtls_sha256_context *ctx,
	int is224 )
	{
	mbedtls_sha256_starts_ret( ctx, is224 );
	}
	#endif

	#if !defined(MBEDTLS_SHA256_PROCESS_ALT)
	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; \
	}

	int mbedtls_internal_sha256_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];

	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
	#endif /* !MBEDTLS_SHA256_PROCESS_ALT */

	/*
	* 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

	/*
	* SHA-256 final digest
	*/
	int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
	unsigned char output[32] )
	{
	int ret;
	uint32_t used;
	uint32_t high, low;

	/*
	* Add padding: 0x80 then 0x00 until 8 bytes remain for the length
	*/
	used = ctx->total[0] & 0x3F;

	ctx->buffer[used++] = 0x80;

	if( used <= 56 )
	{
	/* Enough room for padding + length in current block */
	memset( ctx->buffer + used, 0, 56 - used );
	}
	else
	{
	/* We'll need an extra block */
	memset( ctx->buffer + used, 0, 64 - used );

	if( ( ret = mbedtls_internal_sha256_process( ctx, ctx->buffer ) ) != 0 )
	return( ret );

	memset( ctx->buffer, 0, 56 );
	}

	/*
	* Add message length
	*/
	high = ( ctx->total[0] >> 29 )
	\| ( ctx->total[1] << 3 );
	low = ( ctx->total[0] << 3 );

	PUT_UINT32_BE( high, ctx->buffer, 56 );
	PUT_UINT32_BE( low, ctx->buffer, 60 );

	if( ( ret = mbedtls_internal_sha256_process( ctx, ctx->buffer ) ) != 0 )
	return( ret );

	/*
	* Output final 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 );

	return( 0 );
	}

	#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_ALT */

	/*
	* output = SHA-256( input buffer )
	*/
	int mbedtls_sha256_ret( const unsigned char *input,
	size_t ilen,
	unsigned char output[32],
	int is224 )
	{
	int ret;
	mbedtls_sha256_context ctx;

	mbedtls_sha256_init( &ctx );

	if( ( ret = mbedtls_sha256_starts_ret( &ctx, is224 ) ) != 0 )
	goto exit;

	if( ( ret = mbedtls_sha256_update_ret( &ctx, input, ilen ) ) != 0 )
	goto exit;

	if( ( ret = mbedtls_sha256_finish_ret( &ctx, output ) ) != 0 )
	goto exit;

	exit:
	mbedtls_sha256_free( &ctx );

	return( ret );
	}

	#if !defined(MBEDTLS_DEPRECATED_REMOVED)
	void mbedtls_sha256( const unsigned char *input,
	size_t ilen,
	unsigned char output[32],
	int is224 )
	{
	mbedtls_sha256_ret( input, ilen, output, is224 );
	}
	#endif

	#if defined(MBEDTLS_SELF_TEST)
	/*
	* FIPS-180-2 test vectors
	*/
	static const unsigned char sha256_test_buf[3][57] =
	{
	{ "abc" },
	{ "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq" },
	{ "" }
	};

	static const size_t sha256_test_buflen[3] =
	{
	3, 56, 1000
	};

	static const unsigned char sha256_test_sum[6][32] =
	{
	/*
	* SHA-224 test vectors
	*/
	{ 0x23, 0x09, 0x7D, 0x22, 0x34, 0x05, 0xD8, 0x22,
	0x86, 0x42, 0xA4, 0x77, 0xBD, 0xA2, 0x55, 0xB3,
	0x2A, 0xAD, 0xBC, 0xE4, 0xBD, 0xA0, 0xB3, 0xF7,
	0xE3, 0x6C, 0x9D, 0xA7 },
	{ 0x75, 0x38, 0x8B, 0x16, 0x51, 0x27, 0x76, 0xCC,
	0x5D, 0xBA, 0x5D, 0xA1, 0xFD, 0x89, 0x01, 0x50,
	0xB0, 0xC6, 0x45, 0x5C, 0xB4, 0xF5, 0x8B, 0x19,
	0x52, 0x52, 0x25, 0x25 },
	{ 0x20, 0x79, 0x46, 0x55, 0x98, 0x0C, 0x91, 0xD8,
	0xBB, 0xB4, 0xC1, 0xEA, 0x97, 0x61, 0x8A, 0x4B,
	0xF0, 0x3F, 0x42, 0x58, 0x19, 0x48, 0xB2, 0xEE,
	0x4E, 0xE7, 0xAD, 0x67 },

	/*
	* SHA-256 test vectors
	*/
	{ 0xBA, 0x78, 0x16, 0xBF, 0x8F, 0x01, 0xCF, 0xEA,
	0x41, 0x41, 0x40, 0xDE, 0x5D, 0xAE, 0x22, 0x23,
	0xB0, 0x03, 0x61, 0xA3, 0x96, 0x17, 0x7A, 0x9C,
	0xB4, 0x10, 0xFF, 0x61, 0xF2, 0x00, 0x15, 0xAD },
	{ 0x24, 0x8D, 0x6A, 0x61, 0xD2, 0x06, 0x38, 0xB8,
	0xE5, 0xC0, 0x26, 0x93, 0x0C, 0x3E, 0x60, 0x39,
	0xA3, 0x3C, 0xE4, 0x59, 0x64, 0xFF, 0x21, 0x67,
	0xF6, 0xEC, 0xED, 0xD4, 0x19, 0xDB, 0x06, 0xC1 },
	{ 0xCD, 0xC7, 0x6E, 0x5C, 0x99, 0x14, 0xFB, 0x92,
	0x81, 0xA1, 0xC7, 0xE2, 0x84, 0xD7, 0x3E, 0x67,
	0xF1, 0x80, 0x9A, 0x48, 0xA4, 0x97, 0x20, 0x0E,
	0x04, 0x6D, 0x39, 0xCC, 0xC7, 0x11, 0x2C, 0xD0 }
	};

	/*
	* Checkup routine
	*/
	int mbedtls_sha256_self_test( int verbose )
	{
	int i, j, k, buflen, ret = 0;
	unsigned char *buf;
	unsigned char sha256sum[32];
	mbedtls_sha256_context ctx;

	buf = mbedtls_calloc( 1024, sizeof(unsigned char) );
	if( NULL == buf )
	{
	if( verbose != 0 )
	mbedtls_printf( "Buffer allocation failed\n" );

	return( 1 );
	}

	mbedtls_sha256_init( &ctx );

	for( i = 0; i < 6; i++ )
	{
	j = i % 3;
	k = i < 3;

	if( verbose != 0 )
	mbedtls_printf( " SHA-%d test #%d: ", 256 - k * 32, j + 1 );

	if( ( ret = mbedtls_sha256_starts_ret( &ctx, k ) ) != 0 )
	goto fail;

	if( j == 2 )
	{
	memset( buf, 'a', buflen = 1000 );

	for( j = 0; j < 1000; j++ )
	{
	ret = mbedtls_sha256_update_ret( &ctx, buf, buflen );
	if( ret != 0 )
	goto fail;
	}

	}
	else
	{
	ret = mbedtls_sha256_update_ret( &ctx, sha256_test_buf[j],
	sha256_test_buflen[j] );
	if( ret != 0 )
	goto fail;
	}

	if( ( ret = mbedtls_sha256_finish_ret( &ctx, sha256sum ) ) != 0 )
	goto fail;


	if( memcmp( sha256sum, sha256_test_sum[i], 32 - k * 4 ) != 0 )
	{
	ret = 1;
	goto fail;
	}

	if( verbose != 0 )
	mbedtls_printf( "passed\n" );
	}

	if( verbose != 0 )
	mbedtls_printf( "\n" );

	goto exit;

	fail:
	if( verbose != 0 )
	mbedtls_printf( "failed\n" );

	exit:
	mbedtls_sha256_free( &ctx );
	mbedtls_free( buf );

	return( ret );
	}

	#endif /* MBEDTLS_SELF_TEST */

	#endif /* MBEDTLS_SHA256_C */