Contractless-PHP-Modules/interop

Contractless PHP Crypto Interoperability

This harness verifies that the native libraries packaged by contractless-php-crypto produce data compatible with Contractless.

Results

• The C implementation wrapped by jedisct1/PHP-Skein-Hash produces the same 32-byte Skein-256 output as the Rust skein crate used by Contractless.
• Unmodified Falcon-padded-512 message handling is not compatible with Contractless fn-dsa 0.3.0.
• Falcon-padded-512 keys and fixed signatures use the same Contractless sizes: 897-byte public keys, 1,281-byte private keys, and 666-byte signatures.
• Both signing implementations are compatible when liboqs receives the message framing used by Contractless:

SHAKE256(public_key, 64 bytes) || 0x00 || 0x00 || original_message

The two zero bytes represent raw-message mode and an empty domain context.

With that adapter:

• Contractless Rust signatures verify through liboqs.
• Liboqs signatures verify through Contractless Rust.

Required liboqs algorithm

Use Falcon-padded-512. Do not use variable-length Falcon-512.

Regression requirement

Run these tests whenever Contractless changes its fn-dsa, skein, or signature-framing dependencies. Matching key and signature lengths alone does not establish compatibility.