fn test_agreement_ecdh_x25519_rfc_iterated()

in aws-lc-rs/src/agreement/ephemeral.rs [123:172]

• 44 lines of code
• 2 McCabe index (conditional complexity)

    fn test_agreement_ecdh_x25519_rfc_iterated() {
        fn expect_iterated_x25519(
            expected_result: &str,
            range: core::ops::Range<usize>,
            k: &mut Vec<u8>,
            u: &mut Vec<u8>,
        ) {
            for _ in range {
                let new_k = x25519(k, u);
                u.clone_from(k);
                *k = new_k;
            }
            assert_eq!(&from_hex(expected_result), k);
        }

        let mut k = from_hex("0900000000000000000000000000000000000000000000000000000000000000");
        let mut u = k.clone();

        expect_iterated_x25519(
            "422c8e7a6227d7bca1350b3e2bb7279f7897b87bb6854b783c60e80311ae3079",
            0..1,
            &mut k,
            &mut u,
        );
        expect_iterated_x25519(
            "684cf59ba83309552800ef566f2f4d3c1c3887c49360e3875f2eb94d99532c51",
            1..1_000,
            &mut k,
            &mut u,
        );

        // The spec gives a test vector for 1,000,000 iterations but it takes
        // too long to do 1,000,000 iterations by default right now. This
        // 10,000 iteration vector is self-computed.
        #[cfg(not(disable_slow_tests))]
        expect_iterated_x25519(
            "2c125a20f639d504a7703d2e223c79a79de48c4ee8c23379aa19a62ecd211815",
            1_000..10_000,
            &mut k,
            &mut u,
        );
        /*
               expect_iterated_x25519(
                   "7c3911e0ab2586fd864497297e575e6f3bc601c0883c30df5f4dd2d24f665424",
                   10_000..1_000_000,
                   &mut k,
                   &mut u,
               );
        */
    }