libmicrohttpd2

sha512_256_ext_mbedtls.c (5384B)

---

 /* SPDX-License-Identifier: LGPL-2.1-or-later OR (GPL-2.0-or-later WITH eCos-exception-2.0) */
 /*
   This file is part of GNU libmicrohttpd.
   Copyright (C) 2025 Christian Grothoff
 
   GNU 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.
 
   GNU libmicrohttpd 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.
 
   Alternatively, you can redistribute GNU libmicrohttpd and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of
   the License, or (at your option) any later version, together
   with the eCos exception, as follows:
 
     As a special exception, if other files instantiate templates or
     use macros or inline functions from this file, or you compile this
     file and link it with other works to produce a work based on this
     file, this file does not by itself cause the resulting work to be
     covered by the GNU General Public License. However the source code
     for this file must still be made available in accordance with
     section (3) of the GNU General Public License v2.
 
     This exception does not invalidate any other reasons why a work
     based on this file might be covered by the GNU General Public
     License.
 
   You should have received copies of the GNU Lesser General Public
   License and the GNU General Public License along with this library;
   if not, see <https://www.gnu.org/licenses/>.
 */
 
 /**
  * @file microhttpd/sha512_256_ext_mbedtls.c
  * @brief  Wrapper for SHA-512/256 calculation performed by mbedTLS library
  * @author Christian Grothoff
  */
 
 #include <mbedtls/sha512.h>
 #define MHD_SHA512_256_Context mbedtls_sha512_context
 #include "sha512_256_ext.h"
 #include "mhd_assert.h"
 
 
 /**
  * Initialize mbedtls context for SHA-512/256.
  * Since SHA-512/256 is not natively supported by
  * mbedTLS, we initialize for SHA-512 and then
  * override the state with the SHA-512/256 IV.
  *
  * @param[in,out] ctx hash context to initialize
  */
 static void
 init512_256 (struct mhd_Sha512_256CtxExt *ctx)
 {
   static const uint64_t iv_sha512_256[8] = {
     0x22312194FC2BF72CULL, 0x9F555FA3C84C64C2ULL,
     0x2393B86B6F53B151ULL, 0x963877195940EABDULL,
     0x96283EE2A88EFFE3ULL, 0xBE5E1E2553863992ULL,
     0x2B0199FC2C85B8AAULL, 0x0EB72DDC81C52CA2ULL
   };
 
   mbedtls_sha512_init (ctx->handle);
   /* is384=0 for SHA-512 */
   ctx->ext_error = mbedtls_sha512_starts_ret (ctx->handle,
                                               0);
   if (0 != ctx->ext_error)
   {
     mbedtls_sha512_free (ctx->handle);
     free (ctx->handle);
     ctx->handle = NULL;
     return;
   }
   mhd_assert (sizeof (ctx->handle.state) ==
               sizeof (iv_sha512_256));
   memcpy (ctx->handle.state,
           iv_sha512_256,
           sizeof (iv_sha512_256));
 }
 
 
 /**
  * Initialise structure for SHA-512/256 calculation, allocate resources.
  *
  * This function must not be called more than one time for @a ctx.
  *
  * @param ctx the calculation context
  */
 void
 mhd_SHA512_256_init_one_time (struct mhd_Sha512_256CtxExt *ctx)
 {
   ctx->ext_error = 0;
   ctx->handle = (mbedtls_sha512_context *) malloc (
     sizeof (mbedtls_sha512_context));
   if (NULL == ctx->handle)
   {
     ctx->ext_error = 1; /* Allocation failure */
     return;
   }
 
   init512_256 (ctx);
 
   /* If handle is NULL, the error must be set */
   mhd_assert ((NULL != ctx->handle) || (0 != ctx->ext_error));
   /* If error is set, the handle must be NULL */
   mhd_assert ((0 == ctx->ext_error) || (NULL == ctx->handle));
 }
 
 
 /**
  * Process portion of bytes.
  *
  * @param ctx the calculation context
  * @param data bytes to add to hash
  * @param length number of bytes in @a data
  */
 void
 mhd_SHA512_256_update (struct mhd_Sha512_256CtxExt *ctx,
                        size_t size,
                        const uint8_t *data)
 {
   mhd_assert (0 != size);
 
   if (0 == ctx->ext_error)
     ctx->ext_error = mbedtls_sha512_update_ret (ctx->handle, data, size);
 }
 
 
 /**
  * Finalise SHA-512/256 calculation, return digest, reset hash calculation.
  *
  * @param ctx the calculation context
  * @param[out] digest set to the hash, must be #mhd_SHA512_256_DIGEST_SIZE bytes
  */
 void
 mhd_SHA512_256_finish_reset (struct mhd_Sha512_256CtxExt *ctx,
                              uint8_t digest[mhd_SHA512_256_DIGEST_SIZE])
 {
   uint8_t full_digest[64]; /* SHA-512 produces 64 bytes */
 
   if (0 == ctx->ext_error)
   {
     ctx->ext_error = mbedtls_sha512_finish_ret (ctx->handle,
                                                 full_digest);
 
     if (0 == ctx->ext_error)
     {
       /* SHA-512/256 uses first 32 bytes of SHA-512 with different IV */
       memcpy (digest,
               full_digest,
               mhd_SHA512_256_DIGEST_SIZE);
 
       /* Reset for potential reuse */
       init512_256 (ctx);
     }
   }
 }
 
 
 /**
  * Free allocated resources.
  *
  * @param ctx the calculation context
  */
 void
 mhd_SHA512_256_deinit (struct mhd_Sha512_256CtxExt *ctx)
 {
   if (NULL != ctx->handle)
   {
     mbedtls_sha512_free (ctx->handle);
     free (ctx->handle);
   }
 }