From 4cf645cfc4f58b7612bdbba73158daecb0c0aef4 Mon Sep 17 00:00:00 2001
From: Kevin Trocolli <pitok236@gmail.com>
Date: Thu, 13 Apr 2023 02:30:39 -0400
Subject: [PATCH] util: add hexstring converter

---
 util/hexstr.c    | 36 ++++++++++++++++++++++++++++++++++++
 util/hexstr.h    |  6 ++++++
 util/meson.build |  2 ++
 3 files changed, 44 insertions(+)
 create mode 100644 util/hexstr.c
 create mode 100644 util/hexstr.h

diff --git a/util/hexstr.c b/util/hexstr.c
new file mode 100644
index 0000000..1c41588
--- /dev/null
+++ b/util/hexstr.c
@@ -0,0 +1,36 @@
+#include <windows.h>
+#include <stdint.h>
+#include <string.h>
+#include "util/hexstr.h"
+#include "util/dprintf.h"
+
+HRESULT str_to_bytes(const char *str_in, const size_t str_len, uint8_t *bfr, const size_t bfr_size)
+{
+    if (str_len % 2 != 0) { return E_INVALIDARG; }
+
+    for (int i = 0; i < str_len; i += 2) {
+        if (i >= bfr_size * 2) { break; }
+        
+        char high_c = str_in[i];
+        char low_c = str_in[i + 1];
+        uint8_t val_h = 0;
+        uint8_t val_l = 0;
+        uint8_t val = 0;
+
+        // I hate c
+        val_l = (strtol(&low_c, 0, 16) & 0xF0) >> 4;
+        val_h = strtol(&high_c, 0, 16);
+        bfr[i / 2] = (val_h << 4) + val_l;
+        //dprintf("Util: %c %c -> 0x%X 0x%X -> 0x%02X\n", high_c, low_c, val_h, val_l, bfr[i / 2]);
+    }
+
+    return S_OK;
+}
+
+// TODO
+HRESULT wstr_to_bytes(const wchar_t *str_in, const size_t str_len, uint8_t *bfr, const size_t bfr_size)
+{
+    char buffer[100];
+    wcstombs(buffer, str_in, sizeof(buffer));    
+    return str_to_bytes(buffer, str_len, bfr, bfr_size);
+}
\ No newline at end of file
diff --git a/util/hexstr.h b/util/hexstr.h
new file mode 100644
index 0000000..f931e2b
--- /dev/null
+++ b/util/hexstr.h
@@ -0,0 +1,6 @@
+#pragma once
+#include <windows.h>
+#include <stdint.h>
+
+HRESULT str_to_bytes(const char *str_in, const size_t str_len, uint8_t *bfr, const size_t bfr_size);
+HRESULT wstr_to_bytes(const wchar_t *str_in, const size_t str_len, uint8_t *bfr, const size_t bfr_size);
\ No newline at end of file
diff --git a/util/meson.build b/util/meson.build
index 575d123..d7a646f 100644
--- a/util/meson.build
+++ b/util/meson.build
@@ -21,5 +21,7 @@ util_lib = static_library(
         'lib.h',
         'str.c',
         'str.h',
+        'hexstr.c',
+        'hexstr.h',
     ],
 )