Getting intermittent errors with DSA NIST P521 verification.

[wolfmcnally]

Below is a test that sometimes fails, sometimes succeeds. I can run it several times before it fails. It throws a Crypto error because either r or s are the wrong length.

    #[test]
    fn test_dsa_nistp521() {
        let encoded_key = r#"
-----BEGIN OPENSSH PRIVATE KEY-----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-----END OPENSSH PRIVATE KEY-----
"#;
        let private_key = PrivateKey::from_openssh(encoded_key).unwrap();
        const MESSAGE: &[u8] = b"Ladies and Gentlemen of the class of '99: If I could offer you only one tip for the future, sunscreen would be it.";
        const NAMESPACE: &str = "test";
        let signature = private_key.sign(NAMESPACE, HashAlg::Sha256, MESSAGE).unwrap();
        let public_key = private_key.public_key();
        public_key.verify(NAMESPACE, MESSAGE, &signature).unwrap();
    }

Cargo.toml:

ssh-key = { version = "=0.6.6", default-features = false, features = ["dsa", "ecdsa", "rand_core", "std", "crypto"] }

[tarcieri]

This test succeeds against master, although I'm not sure what changed from v0.6.6 which would cause that to be the case

[tarcieri]

Oh, one thing that would have changed is the RFC6979 implementation. Signatures are now deterministic using that same API where before they used a random k.

[tarcieri]

Going to close this as "can't reproduce". If you encounter this error against master, please reopen.