The initial cut-in was missing preamble present in Moon's curve25519_donna function. It originally tested good because we only perform a pairwise consistency check in release builds. Comprehensive testing with debug builds revealed the problem. Debug builds cross-validate against Bernstein's TweetNaCl library.
Add is_clamped for secret key validation.
Cleanup paramter names in Donna::curve25519 to follow function.
Overload Donna::curve25519 to implicitly use base point if not provided.
Add additional asserts to let the code debug itself.
Update documentation.
The strategy of "cleanup under-aligned buffers" is not scaling well. Corner cases are still turing up. The library has some corner-case breaks, like old 32-bit Intels. And it still has not solved the AltiVec and Power8 alignment problems.
For now we are backing out the changes and investigating other strategies
GCC117 is a Aarch64/ARM64 server with AMD's ARM chip and GCC 7.10. It looks like GCC is performing some std::string optimizations that generates a finding. We did not witness the finding on other platforms, like other Aarch64 devices and x86_64.
We will need to check if taking the address of element-0 is still approved way to get the non-const pointer to the elements
GCC117 is a Aarch64/ARM64 server powered by AMD's ARM chip. It runs GCC 7.10. It looks like GCC is performing some std::string optimizations that generates a finding. We have not witnessed the finding on other platforms
This reverts commit eb3b27a6a5. The change broke GCC 4.8 and unknown version of Clang on OS X. UB reported the OS X break, and JW found duplicated the break on a ARM CubieTruck with GCC 4.8.
They seemed to produce a hang when running self tests in AppVeyor.
Also use IsDebuggerPresent() to determine when we should call DebugBreak(). The OS killed our debug build when fuzzing caused an assert to fail
