hex_util: Add HexVectorToString and HexStringToVector

Converts between bytes and strings when the size is not known at compile time.

src/common/hex_util.cpp

@@ -18,6 +18,25 @@ u8 ToHexNibble(char c1) {
     return 0;
 }
 
+std::vector<u8> HexStringToVector(std::string_view str, bool little_endian) {
+    std::vector<u8> out(str.size() / 2);
+    if (little_endian) {
+        for (std::size_t i = str.size() - 2; i <= str.size(); i -= 2)
+            out[i / 2] = (ToHexNibble(str[i]) << 4) | ToHexNibble(str[i + 1]);
+    } else {
+        for (std::size_t i = 0; i < str.size(); i += 2)
+            out[i / 2] = (ToHexNibble(str[i]) << 4) | ToHexNibble(str[i + 1]);
+    }
+    return out;
+}
+
+std::string HexVectorToString(std::vector<u8> vector, bool upper) {
+    std::string out;
+    for (u8 c : vector)
+        out += fmt::format(upper ? "{:02X}" : "{:02x}", c);
+    return out;
+}
+
 std::array<u8, 16> operator""_array16(const char* str, std::size_t len) {
     if (len != 32) {
         LOG_ERROR(Common,

src/common/hex_util.h

@@ -7,6 +7,7 @@
 #include <array>
 #include <cstddef>
 #include <string>
+#include <vector>
 #include <fmt/format.h>
 #include "common/common_types.h"
 
@@ -14,6 +15,8 @@ namespace Common {
 
 u8 ToHexNibble(char c1);
 
+std::vector<u8> HexStringToVector(std::string_view str, bool little_endian);
+
 template <std::size_t Size, bool le = false>
 std::array<u8, Size> HexStringToArray(std::string_view str) {
     std::array<u8, Size> out{};
@@ -27,6 +30,8 @@ std::array<u8, Size> HexStringToArray(std::string_view str) {
     return out;
 }
 
+std::string HexVectorToString(std::vector<u8> vector, bool upper = true);
+
 template <std::size_t Size>
 std::string HexArrayToString(std::array<u8, Size> array, bool upper = true) {
     std::string out;