wycheproof2blb: secp521r1 support (#980)

Adds support for extracting secp521r1 test vectors from Wycheproof, in
order to test the `p521` crate.

Author: tarcieri

wycheproof2blb/src/ecdsa.rs

@@ -55,7 +55,10 @@ pub fn generator(data: &[u8], algorithm: &str, _key_size: u32) -> Vec<TestInfo>
     let mut infos = vec![];
     for g in &suite.test_groups {
         assert_eq!(g.key.curve, algorithm);
-        assert!(matches!(g.sha.as_str(), "SHA-224" | "SHA-256" | "SHA-384"));
+        assert!(matches!(
+            g.sha.as_str(),
+            "SHA-224" | "SHA-256" | "SHA-384" | "SHA-512"
+        ));
         for tc in &g.tests {
             if tc.case.result == crate::wycheproof::CaseResult::Acceptable {
                 // TODO: figure out what to do with test cases that pass but which have weak params

wycheproof2blb/src/main.rs

@@ -129,6 +129,10 @@ fn main() {
             file: "ecdsa_secp384r1_sha384_test.json",
             generator: ecdsa::generator,
         },
+        "secp521r1" => Algorithm {
+            file: "ecdsa_secp521r1_sha512_test.json",
+            generator: ecdsa::generator,
+        },
         _ => panic!("Unrecognized algorithm '{}'", algorithm),
     };