Squashed commit of the following:

commit 490dfee4ef22479009627435c6ad728c3cbbab54
Author: vnugent <public@vaughnnugent.com>
Date:   Sun Mar 3 14:59:25 2024 -0500

    test: #3 tests for encryption/description and Macs

commit efa97490b7ed47f4e2f05bee52e2b33e14e439e6
Merge: 1b84e3c 120022a
Author: vnugent <public@vaughnnugent.com>
Date:   Sun Mar 3 14:55:48 2024 -0500

    merge master

commit 1b84e3c7c2e55b1ff9ffdd09b66873e11c131441
Author: vnugent <public@vaughnnugent.com>
Date:   Sat Mar 2 22:57:36 2024 -0500

    fix: #2 constent usage of sizeof() operator on struct types

commit 9de5a214c66adea0ef2d0bac63c59449de202a88
Author: vnugent <public@vaughnnugent.com>
Date:   Fri Mar 1 14:30:36 2024 -0500

    perf: avoid nc_key struct copy, cast and verify instead

commit b917b761120ed684af28d0707673ffadcf14b8fe
Author: vnugent <public@vaughnnugent.com>
Date:   Mon Feb 12 22:06:50 2024 -0500

    fix: found the constant time memcompare function

commit 9f85fff3b9f25da7410569ea94f994b88feb3910
Author: vnugent <public@vaughnnugent.com>
Date:   Fri Feb 9 22:48:35 2024 -0500

    feat: added/update MAC functions to sign or verify nip44 payload

commit aa5113741bb419b02d6ea416bba571fa3d65db46
Author: vnugent <public@vaughnnugent.com>
Date:   Wed Feb 7 01:37:53 2024 -0500

    add missing hmac-key output buffer

commit 55f47d22cc9ce4d1e22b70814d608c7ef3b1bbc9
Author: vnugent <public@vaughnnugent.com>
Date:   Sun Feb 4 21:08:13 2024 -0500

    simple bug fixes, and public api argument validation tests

commit 73c5a713fb164ae8b4ac8a891a8020e08eae0a3b
Author: vnugent <public@vaughnnugent.com>
Date:   Fri Feb 2 23:05:48 2024 -0500

    update api to return secpvalidate return code instead of internal return codes

commit 06c73004e1a39a7ea4ea3a89c22dee0f66adb236
Author: vnugent <public@vaughnnugent.com>
Date:   Fri Feb 2 19:25:17 2024 -0500

    change to lgpl license

commit 6e79fdb3b6b6739fc7797d47e55a7691306cf736
Author: vnugent <public@vaughnnugent.com>
Date:   Wed Jan 31 21:30:49 2024 -0500

    move validation macros, and optionally disable them

commit ac1e58837f1ba687939f78b5c03cadd346c10ddd
Author: vnugent <public@vaughnnugent.com>
Date:   Tue Jan 30 12:25:05 2024 -0500

    couple more tests, renable range checks, set flags for all projects

1 files changed, 148 insertions, 0 deletions

diff --git a/tests/hex.h b/tests/hex.h
new file mode 100644
index 0000000..793e9f9
--- /dev/null
+++ b/tests/hex.h
@@ -0,0 +1,148 @@
+/*
+* Copyright (c) 2024 Vaughn Nugent
+*
+* Package: noscrypt
+* File: hex.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 NativeHeapApi. If not, see http://www.gnu.org/licenses/.
+*/
+
+
+#ifndef HEX_HELPERS_H
+#define HEX_HELPERS_H
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
+	#include <assert.h>
+	#define STATIC_ASSERT(x, m) static_assert(x, m)
+#else
+	#define STATIC_ASSERT(x, m)
+	#pragma message("Static assertions are not supported by this language version")
+#endif
+
+typedef struct hexBytes
+{
+	uint8_t* data;
+	size_t length;
+} HexBytes;
+
+/* Deferred list of HexBytes to be freed on exit */
+static HexBytes* _hdeferList[10];
+static size_t _hdeferListIndex = 0;
+
+/* 
+	Allocates a HexBytes and decodes the hexadecimal string into it's binary
+	representation. The string must be a valid hexadecimal string and the length
+	and may not be NULL. The length may be known at compile time and can be used
+    to assert the length of the string literal.
+	@param hexLiteral The hexadecimal string to decode
+	@param strLen The length of the string
+*/
+#define FromHexString(str, len) _fromHexString(str, sizeof(str) - 1); STATIC_ASSERT(sizeof(str)/2 == len && len > 0, "Invalid length hex string literal");
+
+static HexBytes* __allocHexBytes(size_t length)
+{
+	length /= 2;
+
+	HexBytes* hexBytes = (HexBytes*)malloc(length + sizeof(HexBytes));
+	if(!hexBytes)
+	{
+		return NULL;
+	}
+
+	hexBytes->length = length;
+	/* data starts after the structure size */
+	hexBytes-> data = ((uint8_t*)hexBytes) + sizeof(HexBytes);
+	/* add new value to deferred cleanup list */
+	_hdeferList[_hdeferListIndex++] = hexBytes;
+	return hexBytes;
+}
+
+static HexBytes* _fromHexString(const char* hexLiteral, size_t strLen)
+{
+	HexBytes* hexBytes;
+	size_t i;
+
+	if(!hexLiteral)
+	{
+		return NULL;
+	}
+
+	/* alloc the raw bytes */
+	hexBytes = __allocHexBytes(strLen);
+
+	/* read every 2 chars into  */
+	for (i = 0; i < strLen; i += 2)
+	{
+		/* slice string into smaller 2 char strings then parse */
+		char byteString[3] = { hexLiteral[i], hexLiteral[i + 1], '\0'};		
+		hexBytes->data[i / 2] = (uint8_t)strtol(byteString, NULL, 16);
+	}
+	
+	return hexBytes;
+}
+
+/*
+	Frees all the HexBytes that were allocated by the 
+	FromHexString function. To be called at the end of 
+	the program.
+*/
+static void FreeHexBytes(void)
+{
+	while(_hdeferListIndex > 0)
+	{
+		free(_hdeferList[--_hdeferListIndex]);
+		_hdeferList[_hdeferListIndex] = NULL;
+	}
+}
+
+/*
+* Prints the value of the buffer as a hexadecimal string
+* @param bytes The buffer to print
+* @param len The length of the buffer
+*/
+static void PrintHexRaw(void* bytes, size_t len)
+{
+	size_t i;
+	for (i = 0; i < len; i++)
+	{
+		printf("%02x", ((uint8_t*)bytes)[i]);
+	}
+
+	puts("\n");
+}
+
+/*
+* Prints the value of the HexBytes as a hexadecimal string
+* @param hexBytes A pointer to the HexBytes structure to print the value of
+*/
+static void PrintHexBytes(HexBytes* hexBytes)
+{
+	if (!hexBytes)
+	{
+		puts("NULL");
+	}
+	else
+	{
+		PrintHexRaw(hexBytes->data, hexBytes->length);
+	}
+}
+
+
+#endif // !HEX_HELPERS_H
+
+