cortex25519

Implementations of X25519 key agreement and Ed25519 signature verification, optimized with ASM for Cortex-M4 processors or higher (ARMv7e-M or higher).

Not reviewed, could have bugs, use at your own risk, etc etc.

Todo

• ed25519 sign() is not constant time. DO NOT USE IN PRODUCTION. (verify() is OK since it only operates on public data.)
• implement from_bytes_mod_order_wide using the asm field element impl.
• remove dependency on ed25519-dalek.

Credits

Original X25519 ASM implementation by Emil Lenngren.

Extended to support Ed25519 verify by Dario Nieuwenhuis.

Test harness for running Wycheproof test vectors in QEMU is taken from the salty project.

License

• Main cortex25519 crate is available under the BSD 2-clause license.
• Wycheproof test vectors are available under Apache license.
• QEMU test harness is available under Apache + MIT.