fix(servo): gate vulnerable RSA private operations

third_party/rsa/tests/proptests.rs

@@ -0,0 +1,44 @@
+//! Property-based tests.
+
+#![cfg(feature = "hazmat")]
+
+use proptest::prelude::*;
+use rand::rngs::ChaCha8Rng;
+use rand_core::SeedableRng;
+use rsa::{
+    pkcs1v15,
+    signature::{Keypair, SignatureEncoding, Signer, Verifier},
+    RsaPrivateKey,
+};
+use sha2::Sha256;
+
+prop_compose! {
+    // WARNING: do *NOT* copy and paste this code. It's insecure and optimized for test speed.
+    fn private_key()(seed in any::<[u8; 32]>()) -> RsaPrivateKey {
+        let mut rng = ChaCha8Rng::from_seed(seed);
+        RsaPrivateKey::new_unchecked(&mut rng, 512).unwrap()
+    }
+}
+
+proptest! {
+    #[test]
+    fn pkcs1v15_sign_roundtrip(private_key in private_key(), msg in any::<Vec<u8>>()) {
+        let signing_key = pkcs1v15::SigningKey::<Sha256>::new(private_key);
+        let signature_bytes = signing_key.sign(&msg).to_bytes();
+
+        let verifying_key = signing_key.verifying_key();
+        let signature = pkcs1v15::Signature::try_from(&*signature_bytes).unwrap();
+        prop_assert!(verifying_key.verify(&msg, &signature).is_ok());
+    }
+
+    // TODO(tarcieri): debug why these are failing
+    // #[test]
+    // fn pss_sign_roundtrip(private_key in private_key(), msg in any::<Vec<u8>>()) {
+    //     let signing_key = pss::SigningKey::<Sha256>::new(private_key);
+    //     let signature_bytes = signing_key.sign(&msg).to_bytes();
+    //
+    //     let verifying_key = signing_key.verifying_key();
+    //     let signature = pss::Signature::try_from(&*signature_bytes).unwrap();
+    //     prop_assert!(verifying_key.verify(&msg, &signature).is_ok());
+    // }
+}