firedancer

As an example, the Amazon implementation doesn't refer to gcc's[1] and clang's[2] "zero_call_used_regs" to zeroise CPU registers upon return or exception of functions working on crypto secrets. OpenSSL doesn't either.[3] firedancer _does_ use "zero_call_used_regs" to allow gcc/clang to zeroise used CPU registers.[9] As another example, the Amazon implementation also doesn't refer to gcc's "strub" attribute which zeroises the function's stack upon return or exception of functions working on crypto secrets.[4][5] OpenSSL doesn't either.[3] firedancer _does_ use the "strub" attribute to allow gcc to zeroise the function's stack.[9] Is there a performance impact? [6] has the overhead at 0% for X25519 for implementing CPU register and stack zeroisation. Compiling the Linux kernel with "CONFIG_ZERO_CALL_USED_REGS=1" for x64_64 (impacting all ke

It's much more than just performance they've thought about. Here are some of the secure programming practices that have been implemented: /* All the functions in this file are considered "secure", specifically: - Constant time in the input, i.e. the input can be a secret[2] - Small and auditable code base, incl. simple types - Either, no local variables = no need to clear them before exit (most functions) - Or, only static allocation + clear local variable before exit (fd_ed25519_scalar_mul_base_const_time) - Clear registers via FD_FN_SENSITIVE[3] - C safety */ libsodium[4] implements similar mechanisms, and Linux kernel encryption code does too (example: use of kfree_sensitive)[5]. However, firedancer appears to better avoid moving secrets outside of CPU registers, and [3] explains that libraries such a

The firedancer team at one of the better HFT firms wrote an AVX512 optimized implementation of ed25519 and X25519 that’s significantly faster than OpenSSL. https://github.com/firedancer-io/firedancer/pull/716 Ditto for sha256: https://github.com/firedancer-io/firedancer/pull/778 And sha512: https://github.com/firedancer-io/firedancer/pull/760 If you’re an optimization nerd, this codebase is wild.