sha512_256_mbedtls.c (5631B)
1 /* SPDX-License-Identifier: LGPL-2.1-or-later OR (GPL-2.0-or-later WITH eCos-exception-2.0) */ 2 /* 3 This file is part of GNU libmicrohttpd. 4 Copyright (C) 2026 Evgeny Grin (Karlson2k) 5 Copyright (C) 2025 Christian Grothoff 6 7 GNU libmicrohttpd is free software; you can redistribute it and/or 8 modify it under the terms of the GNU Lesser General Public 9 License as published by the Free Software Foundation; either 10 version 2.1 of the License, or (at your option) any later version. 11 12 GNU libmicrohttpd is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 Lesser General Public License for more details. 16 17 Alternatively, you can redistribute GNU libmicrohttpd and/or 18 modify it under the terms of the GNU General Public License as 19 published by the Free Software Foundation; either version 2 of 20 the License, or (at your option) any later version, together 21 with the eCos exception, as follows: 22 23 As a special exception, if other files instantiate templates or 24 use macros or inline functions from this file, or you compile this 25 file and link it with other works to produce a work based on this 26 file, this file does not by itself cause the resulting work to be 27 covered by the GNU General Public License. However the source code 28 for this file must still be made available in accordance with 29 section (3) of the GNU General Public License v2. 30 31 This exception does not invalidate any other reasons why a work 32 based on this file might be covered by the GNU General Public 33 License. 34 35 You should have received copies of the GNU Lesser General Public 36 License and the GNU General Public License along with this library; 37 if not, see <https://www.gnu.org/licenses/>. 38 */ 39 40 /** 41 * @file src/mhd2/sha512_256_mbedtls.c 42 * @brief Wrapper for SHA-512/256 calculation performed by mbedTLS library 43 * @author Karlson2k (Evgeny Grin) 44 * @author Christian Grothoff 45 */ 46 47 #include "mhd_sys_options.h" 48 49 /* mbedTLS does not natively support SHA-512/256: the backend initialises 50 SHA-512 and overrides the internal hash state with the SHA-512/256 initial 51 values, which requires access to private context members. The definition 52 must precede the mbedTLS header so that the private members are visible. */ 53 #ifndef MBEDTLS_ALLOW_PRIVATE_ACCESS 54 # define MBEDTLS_ALLOW_PRIVATE_ACCESS 1 55 #endif 56 57 #include <string.h> 58 #include "mhd_assert.h" 59 #include "mhd_static_assert.h" 60 61 #include "sha512_256_mbedtls.h" 62 63 64 /** 65 * Start SHA-512 calculation and override the internal state with the 66 * SHA-512/256 initial hash values, see FIPS PUB 180-4 clause 5.3.6.2. 67 * 68 * mbedTLS does not natively support SHA-512/256, so the SHA-512 machinery is 69 * reused with a different initial state. 70 * 71 * @param ctx the calculation context, must be already initialised 72 */ 73 static MHD_FN_PAR_NONNULL_ALL_ void 74 mtls_set_sha512_256_iv (struct mhd_Sha512_256CtxMtls *ctx) 75 { 76 static const uint64_t iv_sha512_256[8] = { 77 UINT64_C (0x22312194FC2BF72C), UINT64_C (0x9F555FA3C84C64C2), 78 UINT64_C (0x2393B86B6F53B151), UINT64_C (0x963877195940EABD), 79 UINT64_C (0x96283EE2A88EFFE3), UINT64_C (0xBE5E1E2553863992), 80 UINT64_C (0x2B0199FC2C85B8AA), UINT64_C (0x0EB72DDC81C52CA2) 81 }; 82 83 /* The second argument must be zero to start SHA-512 (not SHA-384) */ 84 ctx->ext_error = (0 != mbedtls_sha512_starts (&(ctx->mbed_ctx), 85 0)); 86 if (ctx->ext_error) 87 return; 88 89 mhd_STATIC_ASSERT_STMT ( 90 sizeof(ctx->mbed_ctx.state) == sizeof(iv_sha512_256), 91 "The mbedTLS SHA-512 state and SHA-512/256 IV sizes must match"); 92 memcpy (ctx->mbed_ctx.state, 93 iv_sha512_256, 94 sizeof(iv_sha512_256)); 95 } 96 97 98 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ MHD_FN_PAR_OUT_ (1) void 99 mhd_SHA512_256_mtls_init (struct mhd_Sha512_256CtxMtls *ctx) 100 { 101 mbedtls_sha512_init (&(ctx->mbed_ctx)); 102 mtls_set_sha512_256_iv (ctx); 103 } 104 105 106 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ MHD_FN_PAR_INOUT_ (1) void 107 mhd_SHA512_256_mtls_reset (struct mhd_Sha512_256CtxMtls *ctx) 108 { 109 if (ctx->ext_error) 110 return; 111 112 mtls_set_sha512_256_iv (ctx); 113 } 114 115 116 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ MHD_FN_PAR_INOUT_ (1) 117 MHD_FN_PAR_IN_SIZE_ (3, 2) void 118 mhd_SHA512_256_mtls_update (struct mhd_Sha512_256CtxMtls *restrict ctx, 119 size_t size, 120 const void *restrict data) 121 { 122 #ifndef MHD_UNIT_TESTING 123 mhd_assert (0 != size); 124 #endif 125 126 if (ctx->ext_error) 127 return; 128 129 ctx->ext_error = (0 != mbedtls_sha512_update (&(ctx->mbed_ctx), 130 (const unsigned char *)data, 131 size)); 132 } 133 134 135 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ MHD_FN_PAR_INOUT_ (1) 136 MHD_FN_PAR_OUT_ (2) void 137 mhd_SHA512_256_mtls_finish ( 138 struct mhd_Sha512_256CtxMtls *restrict ctx, 139 uint8_t digest[MHD_FN_PAR_FIX_ARR_SIZE_ (mhd_SHA512_256_DIGEST_SIZE)]) 140 { 141 uint8_t full_digest[64]; /* SHA-512 produces 64 bytes */ 142 143 if (ctx->ext_error) 144 return; 145 146 ctx->ext_error = (0 != mbedtls_sha512_finish (&(ctx->mbed_ctx), 147 (unsigned char *)full_digest)); 148 if (ctx->ext_error) 149 return; 150 151 /* SHA-512/256 is the leftmost 256 bits of SHA-512 computed with the 152 SHA-512/256 initial values. */ 153 memcpy (digest, 154 full_digest, 155 mhd_SHA512_256_DIGEST_SIZE); 156 } 157 158 159 MHD_INTERNAL MHD_FN_PAR_NONNULL_ALL_ MHD_FN_PAR_INOUT_ (1) void 160 mhd_SHA512_256_mtls_deinit (struct mhd_Sha512_256CtxMtls *ctx) 161 { 162 mbedtls_sha512_free (&(ctx->mbed_ctx)); 163 }