zk syscalls are untested

[jackcmay]

Problem

QSP-4

The following system calls are not tested: • sol_zk_token_elgamal_op; • sol_zk_token_elgamal_op_with_lo_hi; and • sol_zk_token_elgamal_op_with_scalar.

Proposed Solution

Add tests

[jackcmay]

A security auditors brought this up, @samkim-crypto. can we get these tests in?

[samkim-crypto]

These syscalls have been removed (26311) and replaced by the curve25519 syscalls.

[jackcmay]

@samkim-crypto can you point me to the tests for the curve25519 syscalls?

[samkim-crypto]

@jackcmay The curve operations use the dalek library implementation. Currently, there are just tests for native code in the zk-token-sdk

• https://github.com/solana-labs/solana/blob/master/zk-token-sdk/src/curve25519/edwards.rs#L217
• https://github.com/solana-labs/solana/blob/master/zk-token-sdk/src/curve25519/ristretto.rs#L219 and in bpf/rust
• https://github.com/solana-labs/solana/blob/master/programs/bpf/rust/curve25519/src/lib.rs

These syscalls have not been activated yet. If there are places that require more tests before activation, then I'd be happy to add more in.

[jackcmay]

Glad to hear there are tests for the curve operations themselves. We should also have tests for the syscalls themselves (in/out param handling, compute unit consumption, etc...). Take a look at the test for the other syscalls, they are located at the bottom of the file that declares/defines the syscalls

[joncinque]

We'll definitely want these tests if they don't exist -- @samkim-crypto do the tests exist now?