refactor!: Pushing what I have to dev

4 files changed, 198 insertions, 185 deletions

diff --git a/src/internal/nc-util.h b/src/internal/nc-util.h
new file mode 100644
index 0000000..9026d29
--- /dev/null
+++ b/src/internal/nc-util.h
@@ -0,0 +1,62 @@
+
+/*
+* Copyright (c) 2024 Vaughn Nugent
+*
+* Package: noscrypt
+* File: nc-util.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/.
+*/
+
+#pragma once
+
+#ifndef NC_UTIL_H
+#define NC_UTIL_H
+
+/* NULL */
+#ifndef NULL
+	#define NULL ((void*)0)
+#endif /*  !NULL */
+
+
+#ifdef DEBUG
+	/* Must include assert.h for assertions */
+	#include <assert.h> 
+	#define DEBUG_ASSERT(x) assert(x);
+	#define DEBUG_ASSERT2(x, message) assert(x && message);	
+
+	/*
+	* Compiler enabled static assertion keywords are 
+	* only available in C11 and later. Later versions 
+	* have macros built-in from assert.h so we can use
+	* the static_assert macro directly.
+	* 
+	* Static assertions are only used for testing such as 
+	* sanity checks and this library targets the c89 standard
+	* so static_assret very likely will not be available. 
+	*/
+	#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
+		#define STATIC_ASSERT(x, m) static_assert(x, m)
+	#elif !defined(STATIC_ASSERT)
+		#define STATIC_ASSERT(x, m)
+		#pragma message("Static assertions are not supported by this language version")
+	#endif
+
+#else
+	#define DEBUG_ASSERT(x)
+	#define DEBUG_ASSERT2(x, message)
+	#define STATIC_ASSERT(x, m)
+#endif
+
+#endif /* NC_UTIL_H */
\ No newline at end of file
diff --git a/src/noscrypt.c b/src/noscrypt.c
index 3719a08..9271353 100644
--- a/src/noscrypt.c
+++ b/src/noscrypt.c
@@ -15,35 +15,21 @@
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
-* along with NativeHeapApi. If not, see http://www.gnu.org/licenses/.
+* along with noscrypt. If not, see http://www.gnu.org/licenses/.
 */
 
 #include "noscrypt.h"
 
+#include "internal/nc-util.h"
+#include "internal/nc-crypto.h"
+
 #include <secp256k1_ecdh.h>
 #include <secp256k1_schnorrsig.h>
 
-/* Setup mbedtls */
-#include <mbedtls/platform_util.h>
-#include <mbedtls/md.h>
-#include <mbedtls/hkdf.h>
-#include <mbedtls/hmac_drbg.h>
-#include <mbedtls/chacha20.h>
-#include <mbedtls/sha256.h>
-#include <mbedtls/constant_time.h>
-
-/* NULL */
-#ifndef NULL
-	#define NULL ((void*)0)
-#endif /*  !NULL */
-
-#define CHACHA_NONCE_SIZE		0x0cu		/* Size of 12 is set by the cipher spec */
-#define CHACHA_KEY_SIZE			0x20u		/* Size of 32 is set by the cipher spec */
-
 /*
 * Local macro for secure zero buffer fill
 */
-#define ZERO_FILL(x, size) mbedtls_platform_zeroize(x, size) 
+#define ZERO_FILL(x, size) ncCryptoSecureZero(x, size) 
 
 /* Include string for memmove */
 #include <string.h>
@@ -64,36 +50,6 @@
 	#define CHECK_ARG_RANGE(x, min, max, argPos) 
 #endif /* !NC_DISABLE_INPUT_VALIDATION */
 
-
-#ifdef DEBUG
-	/* Must include assert.h for assertions */
-	#include <assert.h> 
-	#define DEBUG_ASSERT(x) assert(x);
-	#define DEBUG_ASSERT2(x, message) assert(x && message);	
-
-	/*
-	* Compiler enabled static assertion keywords are 
-	* only available in C11 and later. Later versions 
-	* have macros built-in from assert.h so we can use
-	* the static_assert macro directly.
-	* 
-	* Static assertions are only used for testing such as 
-	* sanity checks and this library targets the c89 standard
-	* so static_assret very likely will not be available. 
-	*/
-	#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
-		#define STATIC_ASSERT(x, m) static_assert(x, m)
-	#elif !defined(STATIC_ASSERT)
-		#define STATIC_ASSERT(x, m)
-		#pragma message("Static assertions are not supported by this language version")
-	#endif
-
-#else
-	#define DEBUG_ASSERT(x)
-	#define DEBUG_ASSERT2(x, message)
-	#define STATIC_ASSERT(x, m)
-#endif
-
 /*
 * The Nip44 constant salt
 * https://github.com/nostr-protocol/nips/blob/master/44.md#encryption
@@ -129,6 +85,12 @@ struct nc_expand_keys {
 STATIC_ASSERT(sizeof(struct nc_expand_keys) == sizeof(struct message_key), "Expected struct nc_expand_keys to be the same size as struct message_key");
 
 /*
+* Check that the fallback hkdf extract internal buffer is large enough
+* for full converstation key buffers 
+*/
+STATIC_ASSERT(HKDF_IN_BUF_SIZE >= NC_CONV_KEY_SIZE + 8, "HKDF Buffer size is too small for Safe HKDF operations")
+
+/*
 * Internal helper functions to do common structure conversions
 */
 
@@ -246,19 +208,8 @@ static NCResult _computeSharedSecret(
 	return result == 1 ? NC_SUCCESS : E_OPERATION_FAILED;
 }
 
-static _nc_fn_inline const mbedtls_md_info_t* _getSha256MdInfo(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 struct to be valid")
-	return info;
-}
-
-
 static _nc_fn_inline NCResult _computeConversationKey(
 	const NCContext* ctx, 
-	const mbedtls_md_info_t* mdInfo,
 	const struct shared_secret* sharedSecret,
 	struct conversation_key* ck 
 )
@@ -267,12 +218,10 @@ static _nc_fn_inline NCResult _computeConversationKey(
 	
 	DEBUG_ASSERT2(ctx != NULL, "Expected valid context")
 	DEBUG_ASSERT2(sharedSecret != NULL, "Expected a valid shared-point")
-	DEBUG_ASSERT2(mdInfo != NULL, "Expected valid md context")
 	DEBUG_ASSERT2(ck != NULL, "Expected a valid conversation key")
 	
 	/* Derive the encryption key */
-	opResult = mbedtls_hkdf_extract(
-		mdInfo,
+	opResult = ncCryptoSha256HkdfExtract(
 		Nip44ConstantSalt,
 		sizeof(Nip44ConstantSalt),
 		(uint8_t*)sharedSecret,			/* Shared secret is the input key */
@@ -293,23 +242,21 @@ static _nc_fn_inline const struct nc_expand_keys* _expandKeysFromHkdf(const stru
 	return (const struct nc_expand_keys*)hkdf;
 }
 
-static int _chachaEncipher(const struct nc_expand_keys* keys, NCCryptoData* args)
+static int _chachaEncipher(const struct nc_expand_keys* keys, NCEncryptionArgs* args)
 {
 	DEBUG_ASSERT2(keys != NULL, "Expected valid keys")
 	DEBUG_ASSERT2(args != NULL, "Expected valid encryption args")
 
-	return mbedtls_chacha20_crypt(
+	return ncCryptoChacha20(
 		keys->chacha_key,
 		keys->chacha_nonce,
-		0,						/* Counter (always starts at 0) */
-		args->dataSize,			/* Data size (input and output are assumed to be the same size) */
 		args->inputData,		/* Input data */
-		args->outputData		/* Output data */
+		args->outputData,		/* Output data */
+		args->dataSize			/* Data size (input and output are assumed to be the same size) */
 	);
 }
 
 static _nc_fn_inline NCResult _getMessageKey(
-	const mbedtls_md_info_t* mdInfo,
 	const struct conversation_key* converstationKey, 
 	const uint8_t* nonce, 
 	size_t nonceSize,
@@ -317,14 +264,12 @@ static _nc_fn_inline NCResult _getMessageKey(
 )
 {
 	int result;
-	DEBUG_ASSERT2(mdInfo != NULL, "Expected valid md context")
 	DEBUG_ASSERT2(nonce != NULL, "Expected valid nonce buffer")
 	DEBUG_ASSERT2(converstationKey != NULL, "Expected valid conversation key")
 	DEBUG_ASSERT2(messageKey != NULL, "Expected valid message key buffer")
 
 	/* Another HKDF to derive the message key with nonce */
-	result = mbedtls_hkdf_expand(
-		mdInfo,
+	result = ncCryptoSha256HkdfExpand(
 		(uint8_t*)converstationKey,			/* Conversation key is the input key */
 		NC_CONV_KEY_SIZE,
 		nonce,
@@ -338,10 +283,9 @@ static _nc_fn_inline NCResult _getMessageKey(
 
 static _nc_fn_inline NCResult _encryptEx(
 	const NCContext* ctx, 
-	const mbedtls_md_info_t* mdINfo,
 	const struct conversation_key* ck, 
 	uint8_t hmacKey[NC_HMAC_KEY_SIZE],
-	NCCryptoData* args
+	NCEncryptionArgs* args
 )
 {
 	NCResult result;
@@ -351,11 +295,10 @@ static _nc_fn_inline NCResult _encryptEx(
 	DEBUG_ASSERT2(ctx != NULL, "Expected valid context")
 	DEBUG_ASSERT2(ck != NULL, "Expected valid conversation key")
 	DEBUG_ASSERT2(args != NULL, "Expected valid encryption args")
-	DEBUG_ASSERT2(mdINfo != NULL, "Expected valid md info struct")
 	DEBUG_ASSERT2(hmacKey != NULL, "Expected valid hmac key buffer")
 	
 	/* Message key will be derrived on every encryption call */
-	if ((result = _getMessageKey(mdINfo, ck, args->nonce32, NC_ENCRYPTION_NONCE_SIZE, &messageKey)) != NC_SUCCESS)
+	if ((result = _getMessageKey(ck, args->nonce32, NC_ENCRYPTION_NONCE_SIZE, &messageKey)) != NC_SUCCESS)
 	{
 		goto Cleanup;
 	}
@@ -377,9 +320,8 @@ Cleanup:
 
 static _nc_fn_inline NCResult _decryptEx(
 	const NCContext* ctx, 
-	const mbedtls_md_info_t* mdInfo,
 	const struct conversation_key* ck,
-	NCCryptoData* args
+	NCEncryptionArgs* args
 )
 {
 	NCResult result;
@@ -389,9 +331,8 @@ static _nc_fn_inline NCResult _decryptEx(
 	DEBUG_ASSERT2(ctx != NULL, "Expected valid context")
 	DEBUG_ASSERT2(ck != NULL, "Expected valid conversation key")
 	DEBUG_ASSERT2(args != NULL, "Expected valid encryption args")
-	DEBUG_ASSERT2(mdInfo != NULL, "Expected valid md info struct")
 	
-	if ((result = _getMessageKey(mdInfo, ck, args->nonce32, NC_ENCRYPTION_NONCE_SIZE, &messageKey)) != NC_SUCCESS)
+	if ((result = _getMessageKey(ck, args->nonce32, NC_ENCRYPTION_NONCE_SIZE, &messageKey)) != NC_SUCCESS)
 	{
 		goto Cleanup;
 	}
@@ -419,12 +360,9 @@ static _nc_fn_inline int _computeHmac(
 	DEBUG_ASSERT2(hmacOut != NULL, "Expected valid hmac output buffer")
 	DEBUG_ASSERT(args->payload != NULL)
 
-	return mbedtls_md_hmac(
-		_getSha256MdInfo(),
-		key,
-		NC_HMAC_KEY_SIZE,
-		args->payload,
-		args->payloadSize,
+	return ncCryptoHmacSha256(
+		key, NC_HMAC_KEY_SIZE,
+		args->payload, args->payloadSize,
 		hmacOut
 	);
 }
@@ -448,7 +386,6 @@ static NCResult _verifyMacEx(
 	* Message key is again required for the hmac verification
 	*/
 	result = _getMessageKey(
-		_getSha256MdInfo(),
 		(struct conversation_key*)conversationKey,
 		args->nonce32,
 		NC_ENCRYPTION_NONCE_SIZE,
@@ -473,7 +410,7 @@ static NCResult _verifyMacEx(
 	}
 
 	/* constant time compare the macs */
-	result = mbedtls_ct_memcmp(hmacOut, args->mac32, NC_ENCRYPTION_MAC_SIZE) == 0 ? NC_SUCCESS : E_OPERATION_FAILED;
+	result = ncCryptoFixedTimeComp(hmacOut, args->mac32, NC_ENCRYPTION_MAC_SIZE) == 0 ? NC_SUCCESS : E_OPERATION_FAILED;
 
 Cleanup:
 	ZERO_FILL(&messageKey, sizeof(messageKey));
@@ -493,7 +430,7 @@ NC_EXPORT uint32_t NC_CC NCGetContextStructSize(void)
 
 NC_EXPORT NCResult NC_CC NCInitContext(
 	NCContext* ctx, 
-	const uint8_t entropy[32]
+	const uint8_t entropy[NC_CONTEXT_ENTROPY_SIZE]
 )
 {
 	CHECK_NULL_ARG(ctx, 0)
@@ -510,7 +447,7 @@ NC_EXPORT NCResult NC_CC NCInitContext(
 
 NC_EXPORT NCResult NC_CC NCReInitContext(
 	NCContext* ctx, 
-	const uint8_t entropy[32]
+	const uint8_t entropy[NC_CONTEXT_ENTROPY_SIZE]
 )
 {
 	CHECK_NULL_ARG(ctx, 0)
@@ -638,7 +575,7 @@ NC_EXPORT NCResult NC_CC NCSignData(
 	uint8_t sig64[64]
 )
 {
-	uint8_t digest[32];
+	uint8_t digest[SHA256_DIGEST_SIZE];
 
 	/* Double check is required because arg position differs */
 	CHECK_NULL_ARG(ctx, 0)
@@ -649,7 +586,7 @@ NC_EXPORT NCResult NC_CC NCSignData(
 	CHECK_NULL_ARG(sig64, 5)
 
 	/* Compute sha256 of the data before signing */
-	if(mbedtls_sha256(data, dataSize, digest, 0) != 0)
+	if(ncCryptoDigestSha256(data, dataSize, digest) != 0)
 	{
 		return E_INVALID_ARG;
 	}
@@ -696,7 +633,7 @@ NC_EXPORT NCResult NC_CC NCVerifyData(
 	const uint8_t sig64[64]
 )
 {
-	uint8_t digest[32];
+	uint8_t digest[SHA256_DIGEST_SIZE];
 
 	CHECK_NULL_ARG(ctx, 0)
 	CHECK_NULL_ARG(pk, 1)
@@ -705,7 +642,7 @@ NC_EXPORT NCResult NC_CC NCVerifyData(
 	CHECK_NULL_ARG(sig64, 4)
 
 	/* Compute sha256 of the data before verifying */
-	if (mbedtls_sha256(data, dataSize, digest, 0) != 0)
+	if (ncCryptoDigestSha256(data, dataSize, digest) != 0)
 	{
 		return E_INVALID_ARG;
 	}
@@ -729,12 +666,7 @@ NC_EXPORT NCResult NC_CC NCGetSharedSecret(
 	CHECK_NULL_ARG(otherPk, 2)
 	CHECK_NULL_ARG(sharedPoint, 3)	
 
-	return _computeSharedSecret(
-		ctx, 
-		sk, 
-		otherPk, 
-		(struct shared_secret*)sharedPoint
-	);
+	return _computeSharedSecret(ctx, sk, otherPk, (struct shared_secret*)sharedPoint);
 }
 
 NC_EXPORT NCResult NC_CC NCGetConversationKeyEx(
@@ -750,8 +682,7 @@ NC_EXPORT NCResult NC_CC NCGetConversationKeyEx(
 
 	/* Cast the shared point to the shared secret type */
 	return _computeConversationKey(
-		ctx, 
-		_getSha256MdInfo(),
+		ctx,
 		(struct shared_secret*)sharedPoint, 
 		(struct conversation_key*)conversationKey
 	);
@@ -779,12 +710,7 @@ NC_EXPORT NCResult NC_CC NCGetConversationKey(
 		goto Cleanup;
 	}
 
-	result = _computeConversationKey(
-		ctx, 
-		_getSha256MdInfo(),
-		&sharedSecret, 
-		(struct conversation_key*)conversationKey
-	);
+	result = _computeConversationKey(ctx, &sharedSecret, (struct conversation_key*)conversationKey);
 
 Cleanup:
 	/* Clean up sensitive data */
@@ -797,7 +723,7 @@ NC_EXPORT NCResult NC_CC NCEncryptEx(
 	const NCContext* ctx, 
 	const uint8_t conversationKey[NC_CONV_KEY_SIZE], 
 	uint8_t hmacKeyOut[NC_HMAC_KEY_SIZE],
-	NCCryptoData* args
+	NCEncryptionArgs* args
 )
 {
 	CHECK_NULL_ARG(ctx, 0)
@@ -813,8 +739,7 @@ NC_EXPORT NCResult NC_CC NCEncryptEx(
 	CHECK_ARG_RANGE(args->dataSize, NIP44_MIN_ENC_MESSAGE_SIZE, NIP44_MAX_ENC_MESSAGE_SIZE, 3)	
 
 	return _encryptEx(
-		ctx, 
-		_getSha256MdInfo(), 
+		ctx,
 		(struct conversation_key*)conversationKey, 
 		hmacKeyOut,
 		args
@@ -826,11 +751,10 @@ NC_EXPORT NCResult NC_CC NCEncrypt(
 	const NCSecretKey* sk, 
 	const NCPublicKey* pk, 
 	uint8_t hmacKeyOut[NC_HMAC_KEY_SIZE],
-	NCCryptoData* args
+	NCEncryptionArgs* args
 )
 {	
 	NCResult result;
-	const mbedtls_md_info_t* mdInfo;
 	struct shared_secret sharedSecret;
 	struct conversation_key conversationKey;	
 
@@ -847,8 +771,6 @@ NC_EXPORT NCResult NC_CC NCEncrypt(
 	CHECK_INVALID_ARG(args->nonce32, 4)
 	CHECK_ARG_RANGE(args->dataSize, NIP44_MIN_ENC_MESSAGE_SIZE, NIP44_MAX_ENC_MESSAGE_SIZE, 4)
 
-	mdInfo = _getSha256MdInfo();
-
 	/* Compute the shared point */
 	if ((result = _computeSharedSecret(ctx, sk, pk, &sharedSecret)) != NC_SUCCESS)
 	{
@@ -856,12 +778,12 @@ NC_EXPORT NCResult NC_CC NCEncrypt(
 	}
 	
 	/* Compute the conversation key from secret and pubkic keys */
-	if ((result = _computeConversationKey(ctx, mdInfo, &sharedSecret, &conversationKey)) != NC_SUCCESS)
+	if ((result = _computeConversationKey(ctx, &sharedSecret, &conversationKey)) != NC_SUCCESS)
 	{
 		goto Cleanup;
 	}
 
-	result = _encryptEx(ctx, mdInfo, &conversationKey, hmacKeyOut, args);
+	result = _encryptEx(ctx, &conversationKey, hmacKeyOut, args);
 
 Cleanup:
 	/* Clean up sensitive data */
@@ -874,7 +796,7 @@ Cleanup:
 NC_EXPORT NCResult NC_CC NCDecryptEx(
 	const NCContext* ctx, 
 	const uint8_t conversationKey[NC_CONV_KEY_SIZE], 
-	NCCryptoData* args
+	NCEncryptionArgs* args
 )
 {
 	CHECK_NULL_ARG(ctx, 0)
@@ -888,25 +810,19 @@ NC_EXPORT NCResult NC_CC NCDecryptEx(
 	CHECK_INVALID_ARG(args->nonce32, 2)
 	CHECK_ARG_RANGE(args->dataSize, NIP44_MIN_ENC_MESSAGE_SIZE, NIP44_MAX_ENC_MESSAGE_SIZE, 2)
 
-	return _decryptEx(
-		ctx, 
-		_getSha256MdInfo(), 
-		(struct conversation_key*)conversationKey, 
-		args
-	);
+	return _decryptEx(ctx, (struct conversation_key*)conversationKey, args);
 }
 
 NC_EXPORT NCResult NC_CC NCDecrypt(
 	const NCContext* ctx,
 	const NCSecretKey* sk,
 	const NCPublicKey* pk,
-	NCCryptoData* args
+	NCEncryptionArgs* args
 )
 {
 	NCResult result;
 	struct shared_secret sharedSecret;
 	struct conversation_key conversationKey;
-	const mbedtls_md_info_t* mdInfo;
 
 	CHECK_NULL_ARG(ctx, 0)
 	CHECK_INVALID_ARG(ctx->secpCtx, 0)
@@ -920,19 +836,17 @@ NC_EXPORT NCResult NC_CC NCDecrypt(
 	CHECK_INVALID_ARG(args->nonce32, 3)
 	CHECK_ARG_RANGE(args->dataSize, NIP44_MIN_ENC_MESSAGE_SIZE, NIP44_MAX_ENC_MESSAGE_SIZE, 3)
 
-	mdInfo = _getSha256MdInfo();
-
 	if ((result = _computeSharedSecret(ctx, sk, pk, &sharedSecret)) != NC_SUCCESS)
 	{
 		goto Cleanup;
 	}
 
-	if ((result = _computeConversationKey(ctx, mdInfo, &sharedSecret, &conversationKey)) != NC_SUCCESS)
+	if ((result = _computeConversationKey(ctx, &sharedSecret, &conversationKey)) != NC_SUCCESS)
 	{
 		goto Cleanup;
 	}
 
-	result = _decryptEx(ctx, mdInfo, &conversationKey, args);
+	result = _decryptEx(ctx, &conversationKey, args);
 
 Cleanup:
 	/* Clean up sensitive data */
@@ -1018,7 +932,7 @@ NC_EXPORT NCResult NC_CC NCVerifyMac(
 		goto Cleanup;
 	}
 
-	if ((result = _computeConversationKey(ctx, _getSha256MdInfo(), &sharedSecret, &conversationKey)) != NC_SUCCESS)
+	if ((result = _computeConversationKey(ctx, &sharedSecret, &conversationKey)) != NC_SUCCESS)
 	{
 		goto Cleanup;
 	}
diff --git a/src/noscrypt.h b/src/noscrypt.h
index e5dd7aa..06746ce 100644
--- a/src/noscrypt.h
+++ b/src/noscrypt.h
@@ -15,7 +15,7 @@
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
-* along with NativeHeapApi. If not, see http://www.gnu.org/licenses/.
+* along with noscrypt. If not, see http://www.gnu.org/licenses/.
 */
 
 /*
@@ -31,10 +31,7 @@
 
 #include <stdint.h>
 #include <stddef.h>
-
-#if defined(_MSC_VER) || defined(WIN32) || defined(_WIN32)
-	#define _NC_IS_WINDOWS
-#endif
+#include "platform.h"
 
 /* Set api export calling convention (allow used to override) */
 #ifndef NC_CC
@@ -62,25 +59,15 @@
 	#endif /*  !NOSCRYPT_EXPORTING */
 #endif /*  !NC_EXPORT */
 
-#if defined(_NC_IS_WINDOWS) || defined(inline) || defined(__clang__)
-	#define _nc_fn_inline inline
-#elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 allows usage of inline keyword */
-	#define _nc_fn_inline inline
-#elif defined(__GNUC__) || defined(__GNUG__)
-	#define _nc_fn_inline __inline__
-#else
-	#define _nc_fn_inline
-	#pragma message("Warning: No inline keyword defined for this compiler")
-#endif
-
 /*
 * CONSTANTS
 */
 #define BIP340_PUBKEY_HEADER_BYTE		0x02
-#define NIP44_MESSAGE_KEY_SIZE			0x4c	/*32 + 12 + 32 */
+#define NIP44_MESSAGE_KEY_SIZE			0x4c	/*32 + 12 + 32 = 76 */
 #define NC_ENCRYPTION_NONCE_SIZE		0x20
 #define NC_SEC_KEY_SIZE					0x20
 #define NC_PUBKEY_SIZE					0x20
+#define NC_CONTEXT_ENTROPY_SIZE			0x20
 #define NC_SHARED_SEC_SIZE				0x20
 #define NC_CONV_KEY_SIZE				0x20
 #define NC_HMAC_KEY_SIZE				0x20
@@ -122,7 +109,7 @@ defined by the operation.
 typedef int64_t NCResult;
 
 /*
- An secp256k1 secret key (aka 32byte private key buffer)
+ An secp256k1 secret key (aka private key buffer)
 */
 typedef struct secret_key_struct {
 
@@ -159,17 +146,17 @@ typedef struct nc_encryption_struct {
 	const uint8_t* nonce32;
 
 	/* The input data buffer to encrypt/decrypt */
-	const void* inputData;
+	const uint8_t* inputData;
 
 	/* The output data buffer to write data to */
-	void* outputData;
+	uint8_t* outputData;
 
 	/* The size of the data buffers. Buffers must 
 	* be the same size or larger than this value
 	*/
-	uint32_t dataSize;
+	size_t dataSize;
 
-} NCCryptoData;
+} NCEncryptionArgs;
 
 /*
 * A structure for Nip44 message authentication code verification. This structure
@@ -197,8 +184,8 @@ typedef struct nc_mac_verify {
 */
 
 /*
-* A helper function to cast a 32byte buffer to a NCSecretKey struct
-* @param key The 32byte buffer to cast
+* A helper function to cast a buffer to a NCSecretKey struct
+* @param key The buffer to cast
 * @return A pointer to the NCSecretKey struct
 */
 static _nc_fn_inline NCSecretKey* NCToSecKey(uint8_t key[NC_SEC_KEY_SIZE])
@@ -207,8 +194,8 @@ static _nc_fn_inline NCSecretKey* NCToSecKey(uint8_t key[NC_SEC_KEY_SIZE])
 }
 
 /*
-* A helper function to cast a 32byte buffer to a NCPublicKey struct
-* @param key The 32byte buffer to cast
+* A helper function to cast a buffer to a NCPublicKey struct
+* @param key The buffer to cast
 * @return A pointer to the NCPublicKey struct
 */
 static _nc_fn_inline NCPublicKey* NCToPubKey(uint8_t key[NC_PUBKEY_SIZE])
@@ -256,22 +243,22 @@ NC_EXPORT uint32_t NC_CC NCGetContextStructSize(void);
 /*
 * Initializes a context struct with the given entropy
 * @param ctx A pointer to the context structure to initialize
-* @param entropy The 32byte entropy to initialize the context with
+* @param entropy The entropy to initialize the context with
 * @return NC_SUCCESS if the operation was successful, otherwise an error code
 */
 NC_EXPORT NCResult NC_CC NCInitContext(
 	NCContext* ctx, 
-	const uint8_t entropy[32]
+	const uint8_t entropy[NC_CONTEXT_ENTROPY_SIZE]
 );
 /*
 * Reinitializes a context struct with the given 
 * @param ctx A pointer to the context structure to initialize
-* @param entropy The 32byte entropy to initialize the context with
+* @param entropy The entropy to initialize the context with
 * @return NC_SUCCESS if the operation was successful, otherwise an error code
 */
 NC_EXPORT NCResult NC_CC NCReInitContext(
 	NCContext* ctx, 
-	const uint8_t entropy[32]
+	const uint8_t entropy[NC_CONTEXT_ENTROPY_SIZE]
 );
 
 /*
@@ -288,7 +275,7 @@ NC_EXPORT NCResult NC_CC NCDestroyContext(NCContext* ctx);
 */
 
 /*
-* Gets a 32byte x-only compressed public key from the given secret key
+* Gets a x-only compressed public key from the given secret key
 * @param ctx A pointer to the existing library context
 * @param sk A pointer to the secret key
 * @param pk A pointer to the compressed public key buffer to write to
@@ -317,7 +304,7 @@ NC_EXPORT NCResult NC_CC NCValidateSecretKey(
 given secret key and writes the signature to the sig64 buffer.
 * @param ctx A pointer to the existing library context
 * @param sk A pointer to the secret key to sign with
-* @param random32 A pointer to the 32byte random32 buffer to use for signing
+* @param random32 A pointer to the random32 buffer to use for signing
 * @param data A pointer to the raw data buffer to sign
 * @param dataSize The size of the raw data buffer
 * @param sig64 A pointer to the 64byte buffer to write the signature to
@@ -357,8 +344,8 @@ NC_EXPORT NCResult NC_CC NCVerifyData(
 * Signs a message using the given secret key and writes the signature to the sig64 buffer
 * @param ctx A pointer to the existing library context
 * @param sk A pointer to the secret key to sign with
-* @param random32 A pointer to the 32byte random32 buffer to use for signing
-* @param digest32 A pointer to 32byte sha256 digest32 to sign
+* @param random32 A pointer to the random32 buffer to use for signing
+* @param digest32 A pointer to sha256 digest32 to sign
 * @param sig64 A pointer to the 64byte buffer to write the signature to
 * @return NC_SUCCESS if the operation was successful, otherwise an error code
 */
@@ -375,7 +362,7 @@ NC_EXPORT NCResult NC_CC NCSignDigest(
 Equivalent to calling secp256k1_schnorrsig_verify.
 * @param ctx A pointer to the existing library context
 * @param sig64 The 64byte signature to verify
-* @param digest32 The 32byte digest32 to verify
+* @param digest32 The digest32 to verify
 * @param pk A pointer to the the x-only compressed public key (x-only serialized public key)
 * @return NC_SUCCESS if the signature could be verified, otherwise an error code
 */
@@ -407,8 +394,9 @@ NC_EXPORT NCResult NC_CC NCVerifyDigest(
 the NCEncryptEx functions for extended encryption functionality
 * @param ctx The library context
 * @param sk The secret key (the local private key)
-* @param pk The 32byte compressed public key (x-only serialized public key) the other user's public key
+* @param pk The compressed public key (x-only serialized public key) the other user's public key
 * @param args The encryption arguments
+* @param hmacKeyOut A pointer to the buffer to write the hmac key to
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 the error code and positional argument that caused the error
 */
@@ -417,7 +405,7 @@ NC_EXPORT NCResult NC_CC NCEncrypt(
 	const NCSecretKey* sk, 
 	const NCPublicKey* pk, 
 	uint8_t hmacKeyOut[NC_HMAC_KEY_SIZE],
-	NCCryptoData* args
+	NCEncryptionArgs* args
 );
 
 /*
@@ -425,7 +413,7 @@ NC_EXPORT NCResult NC_CC NCEncrypt(
 the NCDecryptEx functions for extended decryption functionality.
 * @param ctx The library context
 * @param sk The secret key (the local private key)
-* @param pk The 32byte compressed public key (x-only serialized public key) the other user's public key
+* @param pk The compressed public key (x-only serialized public key) the other user's public key
 * @param args The decryption arguments
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 the error code and positional argument that caused the error
@@ -434,7 +422,7 @@ NC_EXPORT NCResult NC_CC NCDecrypt(
 	const NCContext* ctx, 
 	const NCSecretKey* sk, 
 	const NCPublicKey* pk, 
-	NCCryptoData* args
+	NCEncryptionArgs* args
 );
 
 /*
@@ -442,7 +430,7 @@ NC_EXPORT NCResult NC_CC NCDecrypt(
 and a public key. Use the NCVerifyMacEx functions for extended verification functionality.
 * @param ctx A pointer to an existing library context
 * @param sk A pointer to the secret key
-* @param pk A pointer to the 32byte compressed public key (x-only serialized public key)
+* @param pk A pointer to the compressed public key (x-only serialized public key)
 * @param args A pointer to the mac verification arguments
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 * the error code and positional argument that caused the error
@@ -463,8 +451,8 @@ NC_EXPORT NCResult NC_CC NCVerifyMac(
 stores it in the sharedPoint buffer.
 * @param ctx A pointer to the existing library context
 * @param sk The secret key
-* @param pk The 32byte compressed public key (x-only serialized public key)
-* @param sharedPoint The 32byte buffer to store write the secret data to
+* @param pk The compressed public key (x-only serialized public key)
+* @param sharedPoint The buffer to store write the secret data to
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 the error code and positional argument that caused the error
 */
@@ -479,9 +467,9 @@ NC_EXPORT NCResult NC_CC NCGetSharedSecret(
 * Computes a NIP-44 conversation key from the local secret key and the remote 
 public key, and stores it in the conversationKey buffer.
 * @param ctx A pointer to the existing library context
-* @param sk A pointer to the 32byte the secret key
-* @param pk A pointer to the 32byte compressed public key (x-only serialized public key)
-* @param conversationKey The 32byte buffer to store write the conversation key to
+* @param sk A pointer to the the secret key
+* @param pk A pointer to the compressed public key (x-only serialized public key)
+* @param conversationKey The buffer to store write the conversation key to
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 the error code and positional argument that caused the error
 */
@@ -495,8 +483,8 @@ NC_EXPORT NCResult NC_CC NCGetConversationKey(
 * Computes a NIP-44 conversation key a shared secret/point, and stores it in the 
 conversationKey buffer.
 * @param ctx A pointer to the existing library context
-* @param sharedPoint A pointer to the 32byte shared secret/point
-* @param conversationKey The 32byte buffer to store write the conversation key to
+* @param sharedPoint A pointer to the shared secret/point
+* @param conversationKey The buffer to store write the conversation key to
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 the error code and positional argument that caused the error
 */
@@ -510,8 +498,9 @@ NC_EXPORT NCResult NC_CC NCGetConversationKeyEx(
 * Encrypts a message using the given conversation key and writes the encrypted message to the
 * output buffer. The output buffer must be at least 99 bytes in size.
 * @param ctx A pointer to the existing library context
-* @param conversationKey A pointer to the 32byte conversation key
+* @param conversationKey A pointer to the conversation key
 * @param args A pointer to the encryption arguments structure
+* @param hmacKeyOut A pointer to the buffer to write the hmac key to
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 the error code and positional argument that caused the error.
 */
@@ -519,14 +508,14 @@ NC_EXPORT NCResult NC_CC NCEncryptEx(
 	const NCContext* ctx, 
 	const uint8_t conversationKey[NC_CONV_KEY_SIZE],
 	uint8_t hmacKeyOut[NC_HMAC_KEY_SIZE],
-	NCCryptoData* args
+	NCEncryptionArgs* args
 );
 
 /*
 * Decrypts a message using the given conversation key and writes the decrypted message to the
 * output buffer. 
 * @param ctx A pointer to the existing library context
-* @param conversationKey A pointer to the 32byte conversation key
+* @param conversationKey A pointer to the conversation key
 * @param args A pointer to the decryption arguments structure
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 the error code and positional argument that caused the error.
@@ -534,13 +523,13 @@ the error code and positional argument that caused the error.
 NC_EXPORT NCResult NC_CC NCDecryptEx(
 	const NCContext* ctx, 
 	const uint8_t conversationKey[NC_CONV_KEY_SIZE], 
-	NCCryptoData* args
+	NCEncryptionArgs* args
 );
 
 /*
 * Verifies a Nip44 message authentication code using the given conversation key.
 * @param ctx A pointer to the existing library context
-* @param conversationKey A pointer to the 32byte conversation key
+* @param conversationKey A pointer to the conversation key
 * @param args A pointer to the mac verification arguments
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 * the error code and positional argument that caused the error.
@@ -555,10 +544,10 @@ NC_EXPORT NCResult NC_CC NCVerifyMacEx(
 * Computes a message authentication code for a given payload using the given hmacKey and writes the
 * mac to the hmacOut buffer.
 * @param ctx A pointer to the existing library context
-* @param hmacKey A pointer to the 32byte hmac key
+* @param hmacKey A pointer to the hmac key
 * @param payload A pointer to the payload data buffer
 * @param payloadSize The size of the payload data buffer
-* @param hmacOut A pointer to the 32byte buffer to write the mac to
+* @param hmacOut A pointer to the buffer to write the mac to
 * @return NC_SUCCESS if the operation was successful, otherwise an error code. Use NCParseErrorCode to
 * the error code and positional argument that caused the error.
 */
diff --git a/src/platform.h b/src/platform.h
new file mode 100644
index 0000000..8abaadd
--- /dev/null
+++ b/src/platform.h
@@ -0,0 +1,48 @@
+/*
+* Copyright (c) 2024 Vaughn Nugent
+*
+* Package: noscrypt
+* File: platform.h
+*
+* 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/.
+*/
+
+
+/*
+*		Contains platform specific defintions
+*/
+
+#if defined(_MSC_VER) || defined(WIN32) || defined(_WIN32)
+	#define _NC_IS_WINDOWS
+#elif defined(__linux__) || defined(__unix__) || defined(__posix__)
+	#define _NC_IS_LINUX
+#elif defined(__APPLE__) || defined(__MACH__)
+	#define _NC_IS_MAC
+#endif
+
+/*
+* Define supported inline defintions for various compilers 
+* and C standards
+*/
+
+#if defined(_NC_IS_WINDOWS) || defined(inline) || defined(__clang__)
+	#define _nc_fn_inline inline
+#elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 allows usage of inline keyword */
+	#define _nc_fn_inline inline
+#elif defined(__GNUC__) || defined(__GNUG__)
+	#define _nc_fn_inline __inline__
+#else
+	#define _nc_fn_inline
+	#pragma message("Warning: No inline keyword defined for this compiler")
+#endif
\ No newline at end of file