tools: Add jsfscramble (Jedi Starfighter cheat scrambler tool)

src/tools/CMakeLists.txt

@@ -14,7 +14,12 @@ target_link_libraries(texdump PUBLIC
 		europa
 		)
 
-add_executable(paktest paktest.cpp)
-target_link_libraries(paktest PUBLIC
+add_executable(jsfscramble jsfscramble.cpp)
+target_link_libraries(jsfscramble PUBLIC
 		europa
 		)
+
+#add_executable(paktest paktest.cpp)
+#target_link_libraries(paktest PUBLIC
+#		europa
+#		)

src/tools/eupak/main.cpp

@@ -121,7 +121,7 @@ int main(int argc, char** argv) {
 		args.outputFile = eupak::fs::path(createParser.get("output"));
 
 		if(createParser.is_used("--archive-version")) {
-				auto& versionStr = createParser.get("--archive-version");
+				const auto& versionStr = createParser.get("--archive-version");
 
 				if(versionStr == "starfighter") {
 					args.pakVersion = europa::structs::PakHeader::Version::Ver4;

src/tools/jsfscramble.cpp

@@ -0,0 +1,69 @@
+//
+// EuropaTools
+//
+// (C) 2021-2023 modeco80 <lily.modeco80@protonmail.ch>
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+// A utility to scramble strings.
+
+#include <cstdint>
+#include <cstdio>
+#include <string>
+#include <string_view>
+
+// Define this to enable an "interactive" mode where the scramble routine will
+// dump out whatever it does to standard out. Undefine this to make it not do so.
+#define INTERACTIVE
+
+template<typename... Args>
+inline std::string StringPrintf(std::string_view format, Args&&... args) {
+	char buffer[1024];
+	auto len = std::snprintf(&buffer[0], sizeof(buffer) - 1, format.data(), static_cast<Args&&>(args)...);
+	if(len == -1)
+		return "";
+	buffer[len] = '\0';
+	return { buffer, static_cast<std::size_t>(len) };
+}
+
+std::uint32_t swsfScramble(const std::string& code) {
+	// The input string needs to be processed before actually scrambling:
+	// - prepend "code_" to it
+	// - make it lowercase
+	auto copy = StringPrintf("code_%s", code.c_str());
+	std::uint32_t tally {};
+	for(auto& c : copy)
+		c = tolower(c);
+
+#ifdef INTERACTIVE
+	std::printf("working with string \"%s\"\n", copy.c_str());
+#endif
+
+	// Now actually do the scramble. The algorithm is pretty simple.
+	for(auto* p = copy.data(); *p; ++p) {
+#ifdef INTERACTIVE
+		std::uint32_t clone = *p;
+		std::printf("load character '%c' -> 0x%08x (%d)\n", *p, clone, clone);
+
+		clone += tally * 5;
+		std::printf("add (0x%08x (%d) * 5) (%d) -> 0x%08x (%d)\n", tally, tally, tally * 5, clone, clone);
+
+		tally = clone;
+#else
+		tally = *p + (tally * 5);
+#endif
+	}
+
+	return tally;
+}
+
+int main(int argc, char** argv) {
+	if(argc < 2) {
+		std::printf("usage: %s [code-string]\n", argv[0]);
+		return 0;
+	}
+
+	auto result = swsfScramble(argv[1]);
+	std::printf("scrambled is: 0x%08x (%d)\n", result, result);
+}