On Thu, Sep 16, 2021 at 8:42 PM austin clifton <austin.clif...@otoy.com> wrote: > > I have an issue which I believe may be a bug. I followed the instructions > from the "Bug Report" page on the cryptopp wiki and all tests in cryptest.exe > are passing, so figured I should post here first and make sure it isn't a > build related issue. > > I built cryptopp 8.5.0 as a static library, x64 multi-threaded debug (\MTd) > using Visual Studio 2019 v16.10.0, on Windows 10 Pro v10.0.19043, using the > .sln file provided with the cryptopp source code. > > I used two different machines for this test. One is the machine I built the > cryptopp library with. Both are running the same version of Windows 10. One > machine has a Ryzen 3700X, the other has an i7-990X. The Ryzen supports AVX, > the i7 does not. > > I am VERY rarely finding that files encrypted with the chacha cipher by these > two machines have differing sha256 hashes. If I do a hex diff against the > files, there is a single flipped bit at 0x1EBB4 (0xD8 vs 0xD9). > > I am able to reproduce this consistently with a specific key, nonce, and > input file, after test encrypting ~50GB of 1MB garbage files on each machine. > > If I disable AVX when building cryptlib by defining CRYPTOPP_DISABLE_AVX and > CRYPTOPP_DISABLE_AVX2, the machine with the Ryzen will encrypt the file the > same as the i7. > > Source code for a minimal reproducible example is here: > https://github.com/austin-clifton/cryptopp-chacha-asm-test/blob/main/src/main.cpp#L208 > > That repository includes a ready-to-build test case with Visual Studio, minus > a built cryptlib.lib which should be added to libs/debug/ before building.
Austin, I fetched main.cpp and run_459_file_76.bin from your GitHub. I compiled the library with: CXXFLAGS="-DNDEBUG -g2 -O3 -std=c++17" make I compiled/linked main.cpp with: g++ -DNDEBUG -g2 -O3 -fPIC -pthread -std=c++17 -I. main.cxx ./libcryptopp.a -o main.exe Running the program on a AMD Ryzen 3 3200U and AMD A6-9220e, this is the result. $ ./main.exe sha256: 0FC0FADCDF82770086C9DA8513A16FC785620D7B1C187CDD828E433EB0979847 encsha: 6FBEE484EE64A2AB02235DDF29CA0B61EE3B811D227C2729836D3BD6161C9B18 Is this correct? I have one Windows machine for testing. It is a Core i5. Sorry I don't have a good test environment. Jeff -- You received this message because you are subscribed to the Google Groups "Crypto++ Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to cryptopp-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cryptopp-users/CAH8yC8k5HNWTq7%2BOx6d27gNh5YwKyi0kxxwDAvMf6QczPcsqhQ%40mail.gmail.com.
