library/sha256.c - mirror/mbed-tls - TrustedFirmware Git Browser

 /*
  *  FIPS-180-2 compliant SHA-256 implementation
  *
  *  Copyright The Mbed TLS Contributors
  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
  */
 /*
  *  The SHA-256 Secure Hash Standard was published by NIST in 2002.
  *
  *  http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
  */

 #include "common.h"

 #if defined(MBEDTLS_SHA256_C)

 #include "mbedtls/sha256.h"
 #include "mbedtls/platform_util.h"
 #include "mbedtls/error.h"

 #include <string.h>

 #include "mbedtls/platform.h"

 #define SHA256_VALIDATE_RET(cond)                           \
     MBEDTLS_INTERNAL_VALIDATE_RET(cond, MBEDTLS_ERR_SHA256_BAD_INPUT_DATA)
 #define SHA256_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE(cond)

 #if !defined(MBEDTLS_SHA256_ALT)

 void mbedtls_sha256_init(mbedtls_sha256_context *ctx)
 {
     SHA256_VALIDATE(ctx != NULL);

     memset(ctx, 0, sizeof(mbedtls_sha256_context));
 }

 void mbedtls_sha256_free(mbedtls_sha256_context *ctx)
 {
     if (ctx == NULL) {
         return;
     }

     mbedtls_platform_zeroize(ctx, sizeof(mbedtls_sha256_context));
 }

 void mbedtls_sha256_clone(mbedtls_sha256_context *dst,
                           const mbedtls_sha256_context *src)
 {
     SHA256_VALIDATE(dst != NULL);
     SHA256_VALIDATE(src != NULL);

     *dst = *src;
 }

 /*
  * SHA-256 context setup
  */
 int mbedtls_sha256_starts_ret(mbedtls_sha256_context *ctx, int is224)
 {
     SHA256_VALIDATE_RET(ctx != NULL);
     SHA256_VALIDATE_RET(is224 == 0 || is224 == 1);

     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)                                                        \
     (                                                               \
         local.W[t] = S1(local.W[(t) -  2]) + local.W[(t) -  7] +    \
                      S0(local.W[(t) - 15]) + local.W[(t) - 16]      \
     )

 #define P(a, b, c, d, e, f, g, h, x, K)                                      \
     do                                                              \
     {                                                               \
         local.temp1 = (h) + S3(e) + F1((e), (f), (g)) + (K) + (x);    \
         local.temp2 = S2(a) + F0((a), (b), (c));                      \
         (d) += local.temp1; (h) = local.temp1 + local.temp2;        \
     } while (0)

 int mbedtls_internal_sha256_process(mbedtls_sha256_context *ctx,
                                     const unsigned char data[64])
 {
     struct {
         uint32_t temp1, temp2, W[64];
         uint32_t A[8];
     } local;

     unsigned int i;

     SHA256_VALIDATE_RET(ctx != NULL);
     SHA256_VALIDATE_RET((const unsigned char *) data != NULL);

     for (i = 0; i < 8; i++) {
         local.A[i] = ctx->state[i];
     }

 #if defined(MBEDTLS_SHA256_SMALLER)
     for (i = 0; i < 64; i++) {
         if (i < 16) {
             local.W[i] = MBEDTLS_GET_UINT32_BE(data, 4 * i);
         } else {
             R(i);
         }

         P(local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
           local.A[5], local.A[6], local.A[7], local.W[i], K[i]);

         local.temp1 = local.A[7]; local.A[7] = local.A[6];
         local.A[6] = local.A[5]; local.A[5] = local.A[4];
         local.A[4] = local.A[3]; local.A[3] = local.A[2];
         local.A[2] = local.A[1]; local.A[1] = local.A[0];
         local.A[0] = local.temp1;
     }
 #else /* MBEDTLS_SHA256_SMALLER */
     for (i = 0; i < 16; i++) {
         local.W[i] = MBEDTLS_GET_UINT32_BE(data, 4 * i);
     }

     for (i = 0; i < 16; i += 8) {
         P(local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
           local.A[5], local.A[6], local.A[7], local.W[i+0], K[i+0]);
         P(local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
           local.A[4], local.A[5], local.A[6], local.W[i+1], K[i+1]);
         P(local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
           local.A[3], local.A[4], local.A[5], local.W[i+2], K[i+2]);
         P(local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
           local.A[2], local.A[3], local.A[4], local.W[i+3], K[i+3]);
         P(local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
           local.A[1], local.A[2], local.A[3], local.W[i+4], K[i+4]);
         P(local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
           local.A[0], local.A[1], local.A[2], local.W[i+5], K[i+5]);
         P(local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
           local.A[7], local.A[0], local.A[1], local.W[i+6], K[i+6]);
         P(local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
           local.A[6], local.A[7], local.A[0], local.W[i+7], K[i+7]);
     }

     for (i = 16; i < 64; i += 8) {
         P(local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
           local.A[5], local.A[6], local.A[7], R(i+0), K[i+0]);
         P(local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
           local.A[4], local.A[5], local.A[6], R(i+1), K[i+1]);
         P(local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
           local.A[3], local.A[4], local.A[5], R(i+2), K[i+2]);
         P(local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
           local.A[2], local.A[3], local.A[4], R(i+3), K[i+3]);
         P(local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
           local.A[1], local.A[2], local.A[3], R(i+4), K[i+4]);
         P(local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
           local.A[0], local.A[1], local.A[2], R(i+5), K[i+5]);
         P(local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
           local.A[7], local.A[0], local.A[1], R(i+6), K[i+6]);
         P(local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
           local.A[6], local.A[7], local.A[0], R(i+7), K[i+7]);
     }
 #endif /* MBEDTLS_SHA256_SMALLER */

     for (i = 0; i < 8; i++) {
         ctx->state[i] += local.A[i];
     }

     /* Zeroise buffers and variables to clear sensitive data from memory. */
     mbedtls_platform_zeroize(&local, sizeof(local));

     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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t fill;
     uint32_t left;

     SHA256_VALIDATE_RET(ctx != NULL);
     SHA256_VALIDATE_RET(ilen == 0 || input != NULL);

     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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     uint32_t used;
     uint32_t high, low;

     SHA256_VALIDATE_RET(ctx != NULL);
     SHA256_VALIDATE_RET((unsigned char *) output != NULL);

     /*
      * 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);

     MBEDTLS_PUT_UINT32_BE(high, ctx->buffer, 56);
     MBEDTLS_PUT_UINT32_BE(low,  ctx->buffer, 60);

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

     /*
      * Output final state
      */
     MBEDTLS_PUT_UINT32_BE(ctx->state[0], output,  0);
     MBEDTLS_PUT_UINT32_BE(ctx->state[1], output,  4);
     MBEDTLS_PUT_UINT32_BE(ctx->state[2], output,  8);
     MBEDTLS_PUT_UINT32_BE(ctx->state[3], output, 12);
     MBEDTLS_PUT_UINT32_BE(ctx->state[4], output, 16);
     MBEDTLS_PUT_UINT32_BE(ctx->state[5], output, 20);
     MBEDTLS_PUT_UINT32_BE(ctx->state[6], output, 24);

     if (ctx->is224 == 0) {
         MBEDTLS_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_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_sha256_context ctx;

     SHA256_VALIDATE_RET(is224 == 0 || is224 == 1);
     SHA256_VALIDATE_RET(ilen == 0 || input != NULL);
     SHA256_VALIDATE_RET((unsigned char *) output != NULL);

     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 The Mbed TLS Contributors
	* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
	*/
	/*
	* The SHA-256 Secure Hash Standard was published by NIST in 2002.
	*
	* http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
	*/

	#include "common.h"

	#if defined(MBEDTLS_SHA256_C)

	#include "mbedtls/sha256.h"
	#include "mbedtls/platform_util.h"
	#include "mbedtls/error.h"

	#include <string.h>

	#include "mbedtls/platform.h"

	#define SHA256_VALIDATE_RET(cond) \
	MBEDTLS_INTERNAL_VALIDATE_RET(cond, MBEDTLS_ERR_SHA256_BAD_INPUT_DATA)
	#define SHA256_VALIDATE(cond) MBEDTLS_INTERNAL_VALIDATE(cond)

	#if !defined(MBEDTLS_SHA256_ALT)

	void mbedtls_sha256_init(mbedtls_sha256_context *ctx)
	{
	SHA256_VALIDATE(ctx != NULL);

	memset(ctx, 0, sizeof(mbedtls_sha256_context));
	}

	void mbedtls_sha256_free(mbedtls_sha256_context *ctx)
	{
	if (ctx == NULL) {
	return;
	}

	mbedtls_platform_zeroize(ctx, sizeof(mbedtls_sha256_context));
	}

	void mbedtls_sha256_clone(mbedtls_sha256_context *dst,
	const mbedtls_sha256_context *src)
	{
	SHA256_VALIDATE(dst != NULL);
	SHA256_VALIDATE(src != NULL);

	dst = src;
	}

	/*
	* SHA-256 context setup
	*/
	int mbedtls_sha256_starts_ret(mbedtls_sha256_context *ctx, int is224)
	{
	SHA256_VALIDATE_RET(ctx != NULL);
	SHA256_VALIDATE_RET(is224 == 0 \|\| is224 == 1);

	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) \
	( \
	local.W[t] = S1(local.W[(t) - 2]) + local.W[(t) - 7] + \
	S0(local.W[(t) - 15]) + local.W[(t) - 16] \
	)

	#define P(a, b, c, d, e, f, g, h, x, K) \
	do \
	{ \
	local.temp1 = (h) + S3(e) + F1((e), (f), (g)) + (K) + (x); \
	local.temp2 = S2(a) + F0((a), (b), (c)); \
	(d) += local.temp1; (h) = local.temp1 + local.temp2; \
	} while (0)

	int mbedtls_internal_sha256_process(mbedtls_sha256_context *ctx,
	const unsigned char data[64])
	{
	struct {
	uint32_t temp1, temp2, W[64];
	uint32_t A[8];
	} local;

	unsigned int i;

	SHA256_VALIDATE_RET(ctx != NULL);
	SHA256_VALIDATE_RET((const unsigned char *) data != NULL);

	for (i = 0; i < 8; i++) {
	local.A[i] = ctx->state[i];
	}

	#if defined(MBEDTLS_SHA256_SMALLER)
	for (i = 0; i < 64; i++) {
	if (i < 16) {
	local.W[i] = MBEDTLS_GET_UINT32_BE(data, 4 * i);
	} else {
	R(i);
	}

	P(local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
	local.A[5], local.A[6], local.A[7], local.W[i], K[i]);

	local.temp1 = local.A[7]; local.A[7] = local.A[6];
	local.A[6] = local.A[5]; local.A[5] = local.A[4];
	local.A[4] = local.A[3]; local.A[3] = local.A[2];
	local.A[2] = local.A[1]; local.A[1] = local.A[0];
	local.A[0] = local.temp1;
	}
	#else /* MBEDTLS_SHA256_SMALLER */
	for (i = 0; i < 16; i++) {
	local.W[i] = MBEDTLS_GET_UINT32_BE(data, 4 * i);
	}

	for (i = 0; i < 16; i += 8) {
	P(local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
	local.A[5], local.A[6], local.A[7], local.W[i+0], K[i+0]);
	P(local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
	local.A[4], local.A[5], local.A[6], local.W[i+1], K[i+1]);
	P(local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
	local.A[3], local.A[4], local.A[5], local.W[i+2], K[i+2]);
	P(local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
	local.A[2], local.A[3], local.A[4], local.W[i+3], K[i+3]);
	P(local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
	local.A[1], local.A[2], local.A[3], local.W[i+4], K[i+4]);
	P(local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
	local.A[0], local.A[1], local.A[2], local.W[i+5], K[i+5]);
	P(local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
	local.A[7], local.A[0], local.A[1], local.W[i+6], K[i+6]);
	P(local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
	local.A[6], local.A[7], local.A[0], local.W[i+7], K[i+7]);
	}

	for (i = 16; i < 64; i += 8) {
	P(local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
	local.A[5], local.A[6], local.A[7], R(i+0), K[i+0]);
	P(local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
	local.A[4], local.A[5], local.A[6], R(i+1), K[i+1]);
	P(local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
	local.A[3], local.A[4], local.A[5], R(i+2), K[i+2]);
	P(local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
	local.A[2], local.A[3], local.A[4], R(i+3), K[i+3]);
	P(local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
	local.A[1], local.A[2], local.A[3], R(i+4), K[i+4]);
	P(local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
	local.A[0], local.A[1], local.A[2], R(i+5), K[i+5]);
	P(local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
	local.A[7], local.A[0], local.A[1], R(i+6), K[i+6]);
	P(local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
	local.A[6], local.A[7], local.A[0], R(i+7), K[i+7]);
	}
	#endif /* MBEDTLS_SHA256_SMALLER */

	for (i = 0; i < 8; i++) {
	ctx->state[i] += local.A[i];
	}

	/* Zeroise buffers and variables to clear sensitive data from memory. */
	mbedtls_platform_zeroize(&local, sizeof(local));

	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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
	size_t fill;
	uint32_t left;

	SHA256_VALIDATE_RET(ctx != NULL);
	SHA256_VALIDATE_RET(ilen == 0 \|\| input != NULL);

	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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
	uint32_t used;
	uint32_t high, low;

	SHA256_VALIDATE_RET(ctx != NULL);
	SHA256_VALIDATE_RET((unsigned char *) output != NULL);

	/*
	* 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);

	MBEDTLS_PUT_UINT32_BE(high, ctx->buffer, 56);
	MBEDTLS_PUT_UINT32_BE(low, ctx->buffer, 60);

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

	/*
	* Output final state
	*/
	MBEDTLS_PUT_UINT32_BE(ctx->state[0], output, 0);
	MBEDTLS_PUT_UINT32_BE(ctx->state[1], output, 4);
	MBEDTLS_PUT_UINT32_BE(ctx->state[2], output, 8);
	MBEDTLS_PUT_UINT32_BE(ctx->state[3], output, 12);
	MBEDTLS_PUT_UINT32_BE(ctx->state[4], output, 16);
	MBEDTLS_PUT_UINT32_BE(ctx->state[5], output, 20);
	MBEDTLS_PUT_UINT32_BE(ctx->state[6], output, 24);

	if (ctx->is224 == 0) {
	MBEDTLS_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_ERR_ERROR_CORRUPTION_DETECTED;
	mbedtls_sha256_context ctx;

	SHA256_VALIDATE_RET(is224 == 0 \|\| is224 == 1);
	SHA256_VALIDATE_RET(ilen == 0 \|\| input != NULL);
	SHA256_VALIDATE_RET((unsigned char *) output != NULL);

	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 */