Fixed a bunch of improper timestamp handling, made ZIP timestamping deterministic, added default timestamp

MakeTimestamp/MakeTimestamp.cpp

@@ -0,0 +1,54 @@
+#include <Windows.h>
+#include <stdio.h>
+#include <stdint.h>
+
+int main(int argc, const char **argv)
+{
+	if (argc != 2)
+	{
+		fprintf(stderr, "Usage: MakeTimestamp <output.ts>\n");
+		fprintf(stderr, "Outputs the current timestamp in 1904 epoch format");
+		return -1;
+	}
+
+	SYSTEMTIME epochStart;
+	epochStart.wYear = 1904;
+	epochStart.wMonth = 1;
+	epochStart.wDayOfWeek = 5;
+	epochStart.wDay = 1;
+	epochStart.wHour = 0;
+	epochStart.wMinute = 0;
+	epochStart.wSecond = 0;
+	epochStart.wMilliseconds = 0;
+
+	FILETIME epochStartFT;
+	if (!SystemTimeToFileTime(&epochStart, &epochStartFT))
+		return 0;
+
+	SYSTEMTIME localTime;
+	GetLocalTime(&localTime);
+
+	FILETIME localTimeFT;
+	SystemTimeToFileTime(&localTime, &localTimeFT);
+
+	int64_t epochStart64 = (static_cast<int64_t>(epochStartFT.dwLowDateTime) & 0xffffffff) | (static_cast<int64_t>(epochStartFT.dwHighDateTime) << 32);
+	int64_t currentTime64 = (static_cast<int64_t>(localTimeFT.dwLowDateTime) & 0xffffffff) | (static_cast<int64_t>(localTimeFT.dwHighDateTime) << 32);
+	int64_t timeDelta = (currentTime64 - epochStart64) / 10000000;
+
+	FILE *f = nullptr;
+	if (fopen_s(&f, argv[1], "wb"))
+	{
+		fprintf(stderr, "Error opening output file");
+		return -1;
+	}
+
+	uint8_t encodedTimestamp[8];
+	for (int i = 0; i < 8; i++)
+		encodedTimestamp[i] = static_cast<uint8_t>((timeDelta >> (i * 8)) & 0xff);
+
+	fwrite(encodedTimestamp, 8, 1, f);
+
+	fclose(f);
+
+	return 0;
+}