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-rw-r--r--src/crypto/impl/bcrypt.c263
-rw-r--r--src/crypto/impl/mbedtls.c172
-rw-r--r--src/crypto/impl/monocypher.c80
-rw-r--r--src/crypto/impl/openssl.c180
4 files changed, 695 insertions, 0 deletions
diff --git a/src/crypto/impl/bcrypt.c b/src/crypto/impl/bcrypt.c
new file mode 100644
index 0000000..9b01cac
--- /dev/null
+++ b/src/crypto/impl/bcrypt.c
@@ -0,0 +1,263 @@
+/*
+* Copyright (c) 2024 Vaughn Nugent
+*
+* Package: noscrypt
+* File: impl/bcrypt.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 provides as many fallback implementations on Windows plaforms
+* as possible using the bcrypt library. This file should be included behind
+* other libarry implementations, as it is a fallback.
+*/
+
+#ifdef _NC_IS_WINDOWS
+
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+#include <bcrypt.h>
+
+#include "nc-util.h"
+#include "hkdf.h"
+
+#define IF_BC_FAIL(x) if(!BCRYPT_SUCCESS(x))
+#define BC_FAIL(x) if(!BCRYPT_SUCCESS(x)) return CSTATUS_FAIL;
+
+struct _bcrypt_ctx
+{
+ BCRYPT_ALG_HANDLE hAlg;
+ BCRYPT_HASH_HANDLE hHash;
+};
+
+_IMPLSTB NTSTATUS _bcInitSha256(struct _bcrypt_ctx* ctx, DWORD flags)
+{
+ NTSTATUS result;
+
+ result = BCryptOpenAlgorithmProvider(
+ &ctx->hAlg,
+ BCRYPT_SHA256_ALGORITHM,
+ NULL,
+ flags
+ );
+
+ /*
+ * If operation failed, ensure the algorithm handle is null
+ * to make free code easier to cleanup
+ */
+ if (!BCRYPT_SUCCESS(result))
+ {
+ ctx->hAlg = NULL;
+ }
+
+ return result;
+}
+
+_IMPLSTB NTSTATUS _bcCreateHmac(struct _bcrypt_ctx* ctx, const cspan_t* key)
+{
+ /*
+ * NOTE:
+ * I am not explicitly managing the update object buffer. By setting
+ * the update object to NULL, and length to 0, the buffer will be
+ * managed by the bcrypt library.
+ *
+ * See: https://learn.microsoft.com/en-us/windows/win32/api/bcrypt/nf-bcrypt-bcryptcreatehash
+ */
+
+ return BCryptCreateHash(
+ ctx->hAlg,
+ &ctx->hHash,
+ NULL,
+ 0,
+ (uint8_t*)key->data,
+ key->size,
+ BCRYPT_HASH_REUSABLE_FLAG /* Enable reusable for expand function */
+ );
+}
+
+_IMPLSTB NTSTATUS _bcCreate(struct _bcrypt_ctx* ctx)
+{
+ cspan_t key;
+
+ /* Zero out key span for 0 size and NULL data ptr */
+ SecureZeroMemory(&key, sizeof(cspan_t));
+
+ return _bcCreateHmac(ctx, &key);
+}
+
+_IMPLSTB NTSTATUS _bcHashDataRaw(const struct _bcrypt_ctx* ctx, const uint8_t* data, uint32_t len)
+{
+ return BCryptHashData(ctx->hHash, (uint8_t*)data, len, 0);
+}
+
+_IMPLSTB NTSTATUS _bcHashData(const struct _bcrypt_ctx* ctx, const cspan_t* data)
+{
+ return _bcHashDataRaw(ctx, data->data, data->size);
+}
+
+_IMPLSTB NTSTATUS _bcFinishHash(const struct _bcrypt_ctx* ctx, sha256_t digestOut32)
+{
+ return BCryptFinishHash(ctx->hHash, digestOut32, sizeof(sha256_t), 0);
+}
+
+_IMPLSTB void _bcDestroyCtx(struct _bcrypt_ctx* ctx)
+{
+ /* Free the update memory if it was allocated */
+ if(ctx->hHash) BCryptDestroyHash(ctx->hHash);
+
+ /* Close the algorithm provider */
+ if (ctx->hAlg) BCryptCloseAlgorithmProvider(ctx->hAlg, 0);
+
+ ctx->hAlg = NULL;
+ ctx->hHash = NULL;
+}
+
+#ifndef _IMPL_SECURE_ZERO_MEMSET
+ /*
+ * On Windows, we can use SecureZeroMemory
+ * as platform zeroing function.
+ *
+ * NOTE:
+ * SecureZeroMemory2 uses volitle function argument
+ * pointers, which is a contested mehtod of compiler
+ * optimization prevention. GNU seems to oppose this method
+ *
+ * https://learn.microsoft.com/en-us/windows/win32/memory/winbase-securezeromemory2
+ */
+ #define _IMPL_SECURE_ZERO_MEMSET SecureZeroMemory
+#endif /* !_IMPL_SECURE_ZERO_MEMSET */
+
+/*
+* Provide win32 fallback for sha256 digest if needed
+*/
+
+#ifndef _IMPL_CRYPTO_SHA256_DIGEST
+
+ /* Export function fallack */
+ #define _IMPL_CRYPTO_SHA256_DIGEST _bcrypt_sha256_digest
+
+ _IMPLSTB cstatus_t _bcrypt_sha256_digest(const cspan_t* data, sha256_t digestOut32)
+ {
+ cstatus_t result;
+ struct _bcrypt_ctx ctx;
+
+ result = CSTATUS_FAIL; /* Start in fail state */
+
+ IF_BC_FAIL(_bcInitSha256(&ctx, 0)) goto Exit;
+
+ IF_BC_FAIL(_bcCreate(&ctx)) goto Exit;
+
+ IF_BC_FAIL(_bcHashData(&ctx, data)) goto Exit;
+
+ IF_BC_FAIL(_bcFinishHash(&ctx, digestOut32)) goto Exit;
+
+ result = CSTATUS_OK; /* Hash operation completed, so set success */
+
+ Exit:
+
+ _bcDestroyCtx(&ctx);
+
+ return result;
+ }
+
+#endif /* !_IMPL_CRYPTO_SHA256_DIGEST */
+
+#ifndef _IMPL_CRYPTO_SHA256_HMAC
+
+ /* Export function */
+ #define _IMPL_CRYPTO_SHA256_HMAC _bcrypt_hmac_sha256
+
+ _IMPLSTB cstatus_t _bcrypt_hmac_sha256(const cspan_t* key, const cspan_t* data, sha256_t hmacOut32)
+ {
+ cstatus_t result;
+ struct _bcrypt_ctx ctx;
+
+ result = CSTATUS_FAIL; /* Start in fail state */
+
+ /* Init context with hmac flag set */
+ IF_BC_FAIL(_bcInitSha256(&ctx, BCRYPT_ALG_HANDLE_HMAC_FLAG)) goto Exit;
+
+ IF_BC_FAIL(_bcCreateHmac(&ctx, key)) goto Exit;
+
+ IF_BC_FAIL(_bcHashData(&ctx, data)) goto Exit;
+
+ IF_BC_FAIL(_bcFinishHash(&ctx, hmacOut32)) goto Exit;
+
+ result = CSTATUS_OK; /* HMAC operation completed, so set success */
+
+ Exit:
+
+ _bcDestroyCtx(&ctx);
+
+ return result;
+ }
+
+#endif /* !_IMPL_CRYPTO_SHA256_HMAC */
+
+/*
+* Provide a fallback HKDF expand function using the
+* HMAC function as a base.
+*/
+
+#ifndef _IMPL_CRYPTO_SHA256_HKDF_EXPAND
+
+ #define _IMPL_CRYPTO_SHA256_HKDF_EXPAND _bcrypt_fallback_hkdf_expand
+
+ cstatus_t _bcrypt_hkdf_update(void* ctx, const cspan_t* data)
+ {
+ DEBUG_ASSERT(ctx != NULL)
+
+ BC_FAIL(_bcHashData((struct _bcrypt_ctx*)ctx, data))
+ return CSTATUS_OK;
+ }
+
+ cstatus_t _bcrypt_hkdf_finish(void* ctx, sha256_t hmacOut32)
+ {
+ DEBUG_ASSERT(ctx != NULL)
+
+ BC_FAIL(_bcFinishHash((struct _bcrypt_ctx*)ctx, hmacOut32))
+ return CSTATUS_OK;
+ }
+
+ _IMPLSTB cstatus_t _bcrypt_fallback_hkdf_expand(const cspan_t* prk, const cspan_t* info, span_t* okm)
+ {
+ cstatus_t result;
+ struct _bcrypt_ctx ctx;
+ struct nc_hkdf_fn_cb_struct handler;
+
+ handler.update = _bcrypt_hkdf_update;
+ handler.finish = _bcrypt_hkdf_finish;
+
+ /* Init bcrypt */
+ BC_FAIL(_bcInitSha256(&ctx, BCRYPT_ALG_HANDLE_HMAC_FLAG))
+
+ BC_FAIL(_bcCreateHmac(&ctx, prk))
+
+ /*
+ * NOTE! Hmac reusable flag must be set to allow for multiple
+ * calls to the finish function without losing the context.
+ */
+
+ result = hkdfExpandProcess(&handler, &ctx, info, okm);
+
+ _bcDestroyCtx(&ctx);
+
+ return result;
+ }
+
+#endif /* !_IMPL_CRYPTO_SHA256_HKDF_EXPAND */
+
+#endif /* _NC_IS_WINDOWS */ \ No newline at end of file
diff --git a/src/crypto/impl/mbedtls.c b/src/crypto/impl/mbedtls.c
new file mode 100644
index 0000000..057e7b4
--- /dev/null
+++ b/src/crypto/impl/mbedtls.c
@@ -0,0 +1,172 @@
+/*
+* 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
+
+/* Inline errors on linux in header files on linux */
+#ifndef inline
+ #define inline __inline
+#endif
+
+#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>
+
+#ifndef inline
+ #undef inline
+#endif
+
+
+_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_int(x) if(x > SIZE_MAX) return 1;
+#else
+ #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
+ )
+ {
+ _overflow_check(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)
+ {
+ _overflow_check(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)
+ {
+ _overflow_check(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 \ No newline at end of file
diff --git a/src/crypto/impl/monocypher.c b/src/crypto/impl/monocypher.c
new file mode 100644
index 0000000..7c9faea
--- /dev/null
+++ b/src/crypto/impl/monocypher.c
@@ -0,0 +1,80 @@
+/*
+* Copyright (c) 2024 Vaughn Nugent
+*
+* Package: noscrypt
+* File: impl/monocypher.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 handles some fallbacks that may not be available on
+* some platforms. More specifically:
+* - Secure memset 0
+* - Chacha20 cipher
+*
+*/
+
+#ifdef NC_ENABLE_MONOCYPHER
+
+#include <monocypher.h>
+
+#include "nc-util.h"
+
+/* Export secure memse0 */
+#ifndef _IMPL_SECURE_ZERO_MEMSET
+
+ /* export cytpo wipe function as is */
+ #define _IMPL_SECURE_ZERO_MEMSET crypto_wipe
+#endif
+
+/* Export Chacha20 */
+#ifndef _IMPL_CHACHA20_CRYPT
+
+ #define _IMPL_CHACHA20_CRYPT _mc_chacha20_crypt
+
+ _IMPLSTB cstatus_t _mc_chacha20_crypt(
+ const uint8_t* key,
+ const uint8_t* nonce,
+ const uint8_t* input,
+ uint8_t* output,
+ uint32_t dataLen
+ )
+ {
+ _overflow_check(dataLen)
+
+ /*
+ * Function returns the next counter value which is not
+ * needed for noscrypt as encryptions are one-shot, and
+ * require a new nonce for each encryption.
+ *
+ * ITEF function uses a 12byte nonce which is required for
+ * nip-44 compliant encryption.
+ */
+ crypto_chacha20_ietf(
+ output,
+ input,
+ (size_t)dataLen,
+ key,
+ nonce,
+ 0x00 /* Counter always starts at 0 */
+ );
+
+ return CSTATUS_OK;
+ }
+
+#endif
+
+#endif /* !NC_ENABLE_MONOCYPHER */ \ No newline at end of file
diff --git a/src/crypto/impl/openssl.c b/src/crypto/impl/openssl.c
new file mode 100644
index 0000000..fd3b4e6
--- /dev/null
+++ b/src/crypto/impl/openssl.c
@@ -0,0 +1,180 @@
+/*
+* Copyright (c) 2024 Vaughn Nugent
+*
+* Package: noscrypt
+* File: impl/openssl.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/.
+*/
+
+
+/* Setup openssl */
+#ifdef OPENSSL_CRYPTO_LIB
+
+#include "nc-util.h"
+#include <openssl/crypto.h>
+
+#define _OSSL_FAIL(x) if(!(x)) return CSTATUS_FAIL;
+
+#ifndef _IMPL_SECURE_ZERO_MEMSET
+
+ #define _IMPL_SECURE_ZERO_MEMSET _ossl_secure_zero_memset
+
+ _IMPLSTB void _ossl_secure_zero_memset(void* ptr, size_t size)
+ {
+ _overflow_check(size)
+
+ OPENSSL_cleanse(ptr, size);
+ }
+#endif
+
+#ifndef _IMPL_CRYPTO_FIXED_TIME_COMPARE
+
+ #define _IMPL_CRYPTO_FIXED_TIME_COMPARE _ossl_fixed_time_compare
+
+ _IMPLSTB uint32_t _ossl_fixed_time_compare(const uint8_t* a, const uint8_t* b, uint32_t size)
+ {
+ int result;
+
+ /* Size checks are required for platforms that have integer sizes under 32bit */
+ _overflow_check(size)
+
+ result = CRYPTO_memcmp(a, b, size);
+
+ return (uint32_t)result;
+ }
+
+#endif /* _IMPL_CRYPTO_FIXED_TIME_COMPARE */
+
+
+#ifndef _IMPL_CRYPTO_SHA256_DIGEST
+
+ #include <openssl/sha.h>
+
+ #define _IMPL_CRYPTO_SHA256_DIGEST _ossl_sha256_digest
+
+ _IMPLSTB cstatus_t _ossl_sha256_digest(const cspan_t* data, sha256_t digestOut32)
+ {
+ _overflow_check(data->size)
+
+ _OSSL_FAIL(SHA256(data->data, data->size, digestOut32))
+
+ return CSTATUS_OK;
+ }
+
+#endif
+
+#ifndef _IMPL_CRYPTO_SHA256_HMAC
+
+ #include <openssl/hmac.h>
+
+ /* Export function */
+ #define _IMPL_CRYPTO_SHA256_HMAC _ossl_hmac_sha256
+
+ _IMPLSTB cstatus_t _ossl_hmac_sha256(const cspan_t* key, const cspan_t* data, sha256_t hmacOut32)
+ {
+ unsigned int hmacLen;
+
+ _overflow_check(key->size)
+ _overflow_check(data->size)
+
+ hmacLen = sizeof(sha256_t);
+
+ _OSSL_FAIL(
+ HMAC(
+ EVP_sha256(),
+ key->data,
+ key->size,
+ data->data,
+ data->size,
+ hmacOut32,
+ &hmacLen
+ )
+ )
+
+ /* digest length should match the actual digest size */
+ DEBUG_ASSERT(hmacLen == sizeof(sha256_t))
+
+ return CSTATUS_OK;
+ }
+
+#endif /* !_IMPL_CRYPTO_SHA256_HMAC */
+
+#ifndef _IMPL_CRYPTO_SHA256_HKDF_EXPAND
+
+ #include <openssl/hmac.h>
+ #include "hkdf.h"
+
+ #define _IMPL_CRYPTO_SHA256_HKDF_EXPAND _ossl_sha256_hkdf_expand
+
+ cstatus_t _ossl_hkdf_update(void* ctx, const cspan_t* data)
+ {
+ DEBUG_ASSERT(ctx != NULL)
+
+ _overflow_check(data->size)
+
+ _OSSL_FAIL(EVP_DigestUpdate((EVP_MD_CTX*)ctx, data->data, data->size))
+
+ return CSTATUS_OK;
+ }
+
+ cstatus_t _ossl_hkdf_finish(void* ctx, sha256_t hmacOut32)
+ {
+ unsigned int hmacSize;
+
+ DEBUG_ASSERT(ctx != NULL)
+
+ hmacSize = sizeof(sha256_t);
+
+ _OSSL_FAIL(EVP_DigestFinal_ex((EVP_MD_CTX*)ctx, hmacOut32, &hmacSize))
+
+ /* When configured for sha256, should always be the same size in/out */
+ DEBUG_ASSERT(hmacSize == sizeof(sha256_t))
+
+ return CSTATUS_OK;
+ }
+
+ _IMPLSTB cstatus_t _ossl_sha256_hkdf_expand(const cspan_t* prk, const cspan_t* info, span_t* okm)
+ {
+ EVP_MD_CTX* ctx;
+ cstatus_t result;
+ struct nc_hkdf_fn_cb_struct handler;
+
+ /*
+ * NOTE! Hmac reusable flag must be set to allow for multiple
+ * calls to the finish function without losing the context.
+ */
+
+ if ((ctx = EVP_MD_CTX_create()) == NULL)
+ {
+ return CSTATUS_FAIL;
+ }
+
+ _OSSL_FAIL(EVP_DigestInit_ex2(ctx, EVP_sha256(), NULL))
+
+ _OSSL_FAIL(EVP_DigestUpdate(ctx, prk->data, prk->size));
+
+ handler.update = _ossl_hkdf_update;
+ handler.finish = _ossl_hkdf_finish;
+
+ result = hkdfExpandProcess(&handler, ctx, info, okm);
+
+ EVP_MD_CTX_destroy(ctx);
+
+ return result;
+ }
+
+#endif /* !_IMPL_CRYPTO_SHA256_HKDF_EXPAND */
+
+#endif /*!OPENSSL_CRYPTO_LIB */ \ No newline at end of file