1 files changed, 388 insertions, 0 deletions
diff --git a/src/providers/openssl-helpers.c b/src/providers/openssl-helpers.c
new file mode 100644
index 0000000..5369457
--- /dev/null
+++ b/src/providers/openssl-helpers.c
@@ -0,0 +1,388 @@
+/*
+* Copyright (c) 2024 Vaughn Nugent
+*
+* Package: noscrypt
+* File: providers/openssl-helpers.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/.
+*/
+
+
+#include <openssl/crypto.h>
+#include <openssl/evp.h>
+
+#define OSSL_SHA256 "SHA2-256"
+#define OSSL_HMAC "hmac"
+#define OSSL_CHACHA20 "ChaCha20"
+
+
+typedef enum {
+	
+	EvpStateTypeInvalid,
+
+	EvpStateTypeDigest,
+	
+	EvpStateTypeMac,
+
+	EvpStateTypeCipher
+
+} _evp_state_type;
+
+struct ossl_evp_state {
+	void* _context;
+	void* _providerHandle;	
+
+	_evp_state_type type;
+
+	cspan_t _prk;
+};
+
+
+_IMPLSTB EVP_MAC_CTX* _osslEvpGetMacContext(const struct ossl_evp_state* state)
+{
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(state->type == EvpStateTypeMac);
+
+	return (EVP_MAC_CTX*)state->_context;
+}
+
+_IMPLSTB EVP_MD_CTX* _osslEvpGetMdContext(const struct ossl_evp_state* state)
+{
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(state->type == EvpStateTypeDigest);
+
+	return (EVP_MD_CTX*)state->_context;
+}
+
+_IMPLSTB EVP_CIPHER_CTX* _osslEvpGetCipherContext(const struct ossl_evp_state* state)
+{
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(state->type == EvpStateTypeCipher);
+
+	return (EVP_CIPHER_CTX*)state->_context;
+}
+
+_IMPLSTB cspan_t _osslEvpGetPrk(const struct ossl_evp_state* state)
+{
+	DEBUG_ASSERT(state != NULL);
+
+	return state->_prk;
+}
+
+_IMPLSTB void _osslEvpSetPrk(struct ossl_evp_state* state, cspan_t prk)
+{
+	DEBUG_ASSERT(state != NULL);
+
+	state->_prk = prk;
+}
+
+_IMPLSTB cstatus_t _osslEvpUpdate(const struct ossl_evp_state* state, cspan_t data)
+{
+	int result;
+
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(state->_context != NULL);
+
+	result = 0;
+
+	switch (state->type)
+	{
+	case EvpStateTypeDigest:
+		result = EVP_DigestUpdate(
+			_osslEvpGetMdContext(state),
+			ncSpanGetOffsetC(data, 0),
+			ncSpanGetSizeC(data)
+		);
+		break;
+
+	case EvpStateTypeMac:
+		result = EVP_MAC_update(
+			_osslEvpGetMacContext(state),
+			ncSpanGetOffsetC(data, 0),
+			ncSpanGetSizeC(data)
+		);
+		break;
+		/* Cipher is not supported by this api */
+	default:
+		DEBUG_ASSERT2(0, "Called update on an invalid state type");
+		break;
+	}
+
+	return (cstatus_t)(result != 0);
+}
+
+_IMPLSTB cstatus_t _osslEvpCipherUpdate(
+	const struct ossl_evp_state* state, 
+	cspan_t input, 
+	span_t output, 
+	int* bytesConsumed
+)
+{
+	int result;
+
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(state->_context != NULL);
+	DEBUG_ASSERT(state->type == EvpStateTypeCipher);
+
+	result = EVP_EncryptUpdate(
+		_osslEvpGetCipherContext(state),
+		ncSpanGetOffset(output, 0),
+		bytesConsumed,
+		ncSpanGetOffsetC(input, 0),
+		ncSpanGetSizeC(input)
+	);
+
+	return (cstatus_t)(result != 0);
+}
+
+_IMPLSTB cstatus_t __digestFinal(const struct ossl_evp_state* state, span_t out)
+{
+	int result;
+	unsigned int mdOut;
+
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(state->type == EvpStateTypeDigest);
+
+	mdOut = ncSpanGetSize(out);
+
+	/* If the output span is empty, nothing to do */
+	if (mdOut == 0)
+	{
+		return CSTATUS_OK;
+	}
+
+	result = EVP_DigestFinal_ex(
+		_osslEvpGetMdContext(state),
+		ncSpanGetOffset(out, 0),
+		&mdOut
+	);
+
+	return (cstatus_t)(result != 0 && mdOut == ncSpanGetSize(out));
+}
+
+_IMPLSTB cstatus_t __macFinal(const struct ossl_evp_state* state, span_t out)
+{
+	int result;
+	size_t macOut;
+
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(state->type == EvpStateTypeMac);
+
+	macOut = ncSpanGetSize(out);
+
+	/* If the output span is empty, nothing to do */
+	if (macOut == 0)
+	{
+		return CSTATUS_OK;
+	}
+
+	result = EVP_MAC_final(
+		_osslEvpGetMacContext(state),
+		ncSpanGetOffset(out, 0),
+		&macOut,
+		macOut
+	);
+
+	return (cstatus_t)(result != 0 && macOut == ncSpanGetSize(out));
+}
+
+_IMPLSTB cstatus_t __cipherFinal(const struct ossl_evp_state* state, span_t out)
+{
+	int result, cipherOut;
+
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(state->type == EvpStateTypeCipher);
+	
+	/* guard small integer overflow */
+	if (ncSpanGetSize(out) > INT_MAX)
+	{
+		return CSTATUS_FAIL;
+	}
+
+	cipherOut = (int)ncSpanGetSize(out);
+
+	/* If the output span is empty, nothing to do */
+	if (cipherOut == 0)
+	{
+		return CSTATUS_OK;
+	}
+
+	result = EVP_CipherFinal_ex(
+		_osslEvpGetCipherContext(state),
+		ncSpanGetOffset(out, 0),
+		&cipherOut
+	);
+
+	return (cstatus_t)(result != 0 && cipherOut >= 0 && (uint32_t)cipherOut == ncSpanGetSize(out));
+}
+
+static cstatus_t _osslEvpFinal(const struct ossl_evp_state* state, span_t out)
+{
+	DEBUG_ASSERT(state != NULL);
+
+	switch (state->type)
+	{
+	case EvpStateTypeDigest:
+		return __digestFinal(state, out);
+
+	case EvpStateTypeMac:
+		return __macFinal(state, out);
+
+	case EvpStateTypeCipher:
+		return __cipherFinal(state, out);
+
+	default:
+		break;
+	}
+
+	/*
+	* If the result is non-zero and the hash length is equal to the output
+	* buffer size, return success, otherwise return failure.
+	*/
+
+	return CSTATUS_FAIL;
+}
+
+_IMPLSTB cstatus_t _osslEvpMacInit(const struct ossl_evp_state* state, const OSSL_PARAM* params)
+{
+	int result;
+
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(state->type == EvpStateTypeMac);
+	DEBUG_ASSERT(ncSpanIsValidC(state->_prk));
+
+	result = EVP_MAC_init(
+		_osslEvpGetMacContext(state),
+		ncSpanGetOffsetC(state->_prk, 0),
+		ncSpanGetSizeC(state->_prk),
+		params
+	);
+
+	return (cstatus_t)(result != 0);
+}
+
+_IMPLSTB cstatus_t _osslEvpCipherInit(const struct ossl_evp_state* state, cspan_t key, cspan_t iv)
+{
+	int osslResult;
+	const EVP_CIPHER* cipher;
+
+	DEBUG_ASSERT(state != NULL);
+
+	cipher = (const EVP_CIPHER*)state->_providerHandle;
+
+	/*
+	* Sanity check on key and IV sizes for the created
+	* cipher
+	*/
+	DEBUG_ASSERT((uint32_t)EVP_CIPHER_get_key_length(cipher) == ncSpanGetSizeC(key));
+	DEBUG_ASSERT((uint32_t)EVP_CIPHER_iv_length(cipher) == ncSpanGetSizeC(iv));
+
+	osslResult = EVP_EncryptInit_ex2(
+		_osslEvpGetCipherContext(state),
+		cipher,
+		ncSpanGetOffsetC(key, 0),
+		ncSpanGetOffsetC(iv, 0),
+		NULL
+	);
+
+	return (cstatus_t)(osslResult != 0);
+}
+
+_IMPLSTB void _osslEvpFree(struct ossl_evp_state* state)
+{
+	DEBUG_ASSERT(state != NULL);
+
+	switch (state->type)
+	{
+	case EvpStateTypeDigest:
+		if (state->_context) EVP_MD_CTX_free(state->_context);
+		if (state->_providerHandle) EVP_MD_free(state->_providerHandle);
+		break;
+	case EvpStateTypeMac:
+		if (state->_context) EVP_MAC_CTX_free(state->_context);
+		if (state->_providerHandle) EVP_MAC_free(state->_providerHandle);
+		break;
+	case EvpStateTypeCipher:
+		if (state->_context) EVP_CIPHER_CTX_free(state->_context);
+		if (state->_providerHandle) EVP_CIPHER_free(state->_providerHandle);
+		break;
+	default:
+		break;
+	}
+}
+
+_IMPLSTB cstatus_t _osslEvpInit(
+	struct ossl_evp_state* state,
+	_evp_state_type type,
+	const char* providerName
+)
+{
+	DEBUG_ASSERT(state != NULL);
+	DEBUG_ASSERT(providerName != NULL);
+
+	state->type = type;
+
+	switch (type)
+	{
+	case EvpStateTypeDigest:
+		state->_providerHandle = EVP_MD_fetch(NULL, providerName, NULL);
+		state->_context = EVP_MD_CTX_new();		
+		break;
+	case EvpStateTypeMac:
+
+		state->_providerHandle = EVP_MAC_fetch(NULL, providerName, NULL);
+
+		if (state->_providerHandle)
+		{
+			state->_context = EVP_MAC_CTX_new((EVP_MAC*)(state->_providerHandle));
+		}
+
+		break;
+	case EvpStateTypeCipher:
+		state->_providerHandle = EVP_CIPHER_fetch(NULL, providerName, NULL);
+		state->_context = EVP_CIPHER_CTX_new();
+		break;
+
+	default:
+		return CSTATUS_FAIL;
+	}
+
+	/*
+	* Ensure allocations succeded, otherwise free the context
+	* and return a failure status.
+	*/
+	if (state->_providerHandle == NULL || state->_context == NULL)
+	{		
+		return CSTATUS_FAIL;
+	}
+
+	/*
+	* If the type is a digest, initialize the digest context
+	*/
+	if (type == EvpStateTypeDigest)
+	{
+		if (
+			!EVP_DigestInit_ex(
+				_osslEvpGetMdContext(state),
+				(EVP_MD*)state->_providerHandle,
+				NULL
+			)
+		)
+		{
+			return CSTATUS_FAIL;
+		}
+	}
+
+	return CSTATUS_OK;
+}