diff --git a/src/misc.cpp b/src/misc.cpp --- a/src/misc.cpp +++ b/src/misc.cpp @@ -31,7 +31,7 @@ #include "town_kdtree.h" #include "viewport_kdtree.h" #include "newgrf_profiling.h" -#include "3rdparty/md5/md5.h" +#include "3rdparty/monocypher/monocypher.h" #include "safeguards.h" @@ -61,25 +61,24 @@ void InitializeOldNames(); /** * Generate an unique ID. * - * It isn't as much of an unique ID as we would like, but our random generator - * can only produce 32bit random numbers. - * That is why we combine InteractiveRandom with the current (steady) clock. - * The first to add a bit of randomness, the second to ensure you can't get - * the same unique ID when you run it twice from the same state at different - * times. - * - * This makes it unlikely that two users generate the same ID for different - * subjects. But as this is not an UUID, so it can't be ruled out either. + * It isn't as much of an unique ID but more a hashed digest of a random + * string and a time. It is very likely to be unique, but it does not follow + * any UUID standard. */ std::string GenerateUid(std::string_view subject) { + std::array random_bytes; + RandomBytesWithFallback(random_bytes); + auto current_time = std::chrono::duration_cast(std::chrono::steady_clock::now().time_since_epoch()).count(); - std::string coding_string = fmt::format("{}{}{}", InteractiveRandom(), current_time, subject); + std::string coding_string = fmt::format("{}{}", current_time, subject); - Md5 checksum; - MD5Hash digest; - checksum.Append(coding_string.c_str(), coding_string.length()); - checksum.Finish(digest); + std::array digest; + crypto_blake2b_ctx ctx; + crypto_blake2b_init(&ctx, digest.size()); + crypto_blake2b_update(&ctx, random_bytes.data(), random_bytes.size()); + crypto_blake2b_update(&ctx, reinterpret_cast(coding_string.data()), coding_string.size()); + crypto_blake2b_final(&ctx, digest.data()); return FormatArrayAsHex(digest); }