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Diffstat (limited to 'src/crypto/impl/mbedtls.c')
| -rw-r--r-- | src/crypto/impl/mbedtls.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/src/crypto/impl/mbedtls.c b/src/crypto/impl/mbedtls.c new file mode 100644 index 0000000..ae36bbd --- /dev/null +++ b/src/crypto/impl/mbedtls.c @@ -0,0 +1,170 @@ +/* +* Copyright (c) 2024 Vaughn Nugent +* +* Package: noscrypt +* File: mbedtls.c +* +* This library 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. +* +* This library 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. +* +* You should have received a copy of the GNU Lesser General Public License +* along with noscrypt. If not, see http://www.gnu.org/licenses/. +*/ + + +/* +* This file contains implemntation functions for the required +* cryptography primitives of noscrypt. This file stubs functionality +* using the Mbed-TLS library, if the builder desires to link against +* it. +*/ + +#ifdef MBEDTLS_CRYPTO_LIB + +#include <mbedtls/md.h> +#include <mbedtls/hkdf.h> +#include <mbedtls/hmac_drbg.h> +#include <mbedtls/sha256.h> +#include <mbedtls/chacha20.h> +#include <mbedtls/constant_time.h> + +#include "nc-util.h" + +/* +* EXPORT SUPPORTED FUNCTION OVERRIDES +*/ + +_IMPLSTB const mbedtls_md_info_t* _mbed_sha256_alg(void) +{ + const mbedtls_md_info_t* info; + /* Get sha256 md info for hdkf operations */ + info = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256); + DEBUG_ASSERT2(info != NULL, "Expected SHA256 md info pointer to be valid") + return info; +} + +#if SIZE_MAX < UINT64_MAX + #define _ssize_guard(x) if(x > SIZE_MAX) return CSTATUS_FAIL; + #define _ssize_guard_int(x) if(x > SIZE_MAX) return 1; +#else + #define _ssize_guard(x) + #define _ssize_guard_int(x) +#endif + +#ifndef _IMPL_CHACHA20_CRYPT + + /* Export chacha20 computation */ + #define _IMPL_CHACHA20_CRYPT _mbed_chacha20_encrypt + + _IMPLSTB cstatus_t _mbed_chacha20_encrypt( + const uint8_t* key, + const uint8_t* nonce, + const uint8_t* input, + uint8_t* output, + uint32_t dataLen + ) + { + _ssize_guard(dataLen) + + /* Counter always starts at 0 */ + return mbedtls_chacha20_crypt( + key, + nonce, + 0x00u, /* nip-44 counter version */ + dataLen, + input, + output + ) == 0 ? CSTATUS_OK : CSTATUS_FAIL; + } + +#endif + +/* Export sha256 if not already defined */ +#ifndef _IMPL_CRYPTO_SHA256_DIGEST + + #define _IMPL_CRYPTO_SHA256_DIGEST _mbed_sha256_digest + + _IMPLSTB cstatus_t _mbed_sha256_digest(const cspan_t* data, sha256_t digestOut32) + { + _ssize_guard(data->size) + + return mbedtls_sha256( + data->data, + data->size, + digestOut32, + 0 /* Set 0 for sha256 mode */ + ) == 0 ? CSTATUS_OK : CSTATUS_FAIL; + } + +#endif + +/* Export Sha256 hmac if not already defined by other libs */ +#ifndef _IMPL_CRYPTO_SHA256_HMAC + + #define _IMPL_CRYPTO_SHA256_HMAC _mbed_sha256_hmac + + _IMPLSTB cstatus_t _mbed_sha256_hmac(const cspan_t* key, const cspan_t* data, sha256_t hmacOut32) + { + _ssize_guard(data->size) + + /* Keys should never be large enough for this to matter, but sanity check. */ + DEBUG_ASSERT2(key->size < SIZE_MAX, "Expected key size to be less than SIZE_MAX") + + return mbedtls_md_hmac( + _mbed_sha256_alg(), + key->data, + key->size, + data->data, + data->size, + hmacOut32 + ) == 0 ? CSTATUS_OK : CSTATUS_FAIL; + } +#endif + +/* Export hkdf expand if not already defined */ +#ifndef _IMPL_CRYPTO_SHA256_HKDF_EXPAND + + #define _IMPL_CRYPTO_SHA256_HKDF_EXPAND _mbed_sha256_hkdf_expand + + _IMPLSTB cstatus_t _mbed_sha256_hkdf_expand(const cspan_t* prk, const cspan_t* info, span_t* okm) + { + /* These sizes should never be large enough to overflow on <64bit platforms, but sanity check */ + DEBUG_ASSERT(okm->size < SIZE_MAX) + DEBUG_ASSERT(prk->size < SIZE_MAX) + DEBUG_ASSERT(info->size < SIZE_MAX) + + return mbedtls_hkdf_expand( + _mbed_sha256_alg(), + prk->data, + prk->size, + info->data, + info->size, + okm->data, + okm->size + ) == 0 ? CSTATUS_OK : CSTATUS_FAIL; + } + +#endif + +/* Export fixed-time compare if not already defined */ +#ifndef _IMPL_CRYPTO_FIXED_TIME_COMPARE + + #define _IMPL_CRYPTO_FIXED_TIME_COMPARE _mbed_fixed_time_compare + + /* fixed-time memcmp */ + _IMPLSTB uint32_t _mbed_fixed_time_compare(const uint8_t* a, const uint8_t* b, uint32_t size) + { + _ssize_guard_int(size) + + return (uint32_t)mbedtls_ct_memcmp(a, b, size); + } +#endif + +#endif
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