Make ecdsa_verify_cose testable
Add ecdsa_sign_cose (and rename the existing ecdsa_sign to
ecdsa_sign_der). Implement DER to COSE signature conversion to support
this.
Fix terminology - COSE format rather than NIST format.
Add tests to ensure that signing & verification are compatible.
Note that while I'm adding code to the production bssl library, none
of it is currently used other than in the new tests, so this shouldn't
break anything.
Bug: 338745127
Test: atest libbssl_avf_nostd.test
Change-Id: Ie522f556f90c4515b4f738a23a42c02ff48b073e
diff --git a/libs/bssl/tests/eckey_test.rs b/libs/bssl/tests/eckey_test.rs
index 00ed6c5..0fc78a1 100644
--- a/libs/bssl/tests/eckey_test.rs
+++ b/libs/bssl/tests/eckey_test.rs
@@ -87,7 +87,7 @@
let digest = digester.digest(MESSAGE1)?;
assert_eq!(digest, sha256(MESSAGE1)?);
- let signature = ec_key.ecdsa_sign(&digest)?;
+ let signature = ec_key.ecdsa_sign_der(&digest)?;
ec_key.ecdsa_verify_der(&signature, &digest)?;
// Building a `PKey` from a temporary `CoseKey` should work as the lifetime
// of the `PKey` is not tied to the lifetime of the `CoseKey`.
@@ -102,7 +102,7 @@
let digester = Digester::sha384();
let digest = digester.digest(MESSAGE1)?;
- let signature = ec_key.ecdsa_sign(&digest)?;
+ let signature = ec_key.ecdsa_sign_der(&digest)?;
ec_key.ecdsa_verify_der(&signature, &digest)?;
let pkey = PKey::from_cose_public_key(&ec_key.cose_public_key()?)?;
pkey.verify(&signature, MESSAGE1, Some(digester))
@@ -113,7 +113,7 @@
let mut ec_key1 = EcKey::new_p256()?;
ec_key1.generate_key()?;
let digest = sha256(MESSAGE1)?;
- let signature = ec_key1.ecdsa_sign(&digest)?;
+ let signature = ec_key1.ecdsa_sign_der(&digest)?;
let mut ec_key2 = EcKey::new_p256()?;
ec_key2.generate_key()?;
@@ -134,7 +134,7 @@
let mut ec_key = EcKey::new_p256()?;
ec_key.generate_key()?;
let digest1 = sha256(MESSAGE1)?;
- let signature = ec_key.ecdsa_sign(&digest1)?;
+ let signature = ec_key.ecdsa_sign_der(&digest1)?;
let digest2 = sha256(MESSAGE2)?;
let err = ec_key.ecdsa_verify_der(&signature, &digest2).unwrap_err();
@@ -142,3 +142,42 @@
assert_eq!(expected_err, err);
Ok(())
}
+
+#[test]
+fn ecdsa_cose_signing_and_verification_succeed() -> Result<()> {
+ let digest = sha256(MESSAGE1)?;
+ let mut ec_key = EcKey::new_p256()?;
+ ec_key.generate_key()?;
+
+ let signature = ec_key.ecdsa_sign_cose(&digest)?;
+ ec_key.ecdsa_verify_cose(&signature, &digest)?;
+ assert_eq!(signature.len(), 64);
+ Ok(())
+}
+
+#[test]
+fn verifying_ecdsa_cose_signed_with_a_different_message_fails() -> Result<()> {
+ let digest = sha256(MESSAGE1)?;
+ let mut ec_key = EcKey::new_p256()?;
+ ec_key.generate_key()?;
+
+ let signature = ec_key.ecdsa_sign_cose(&digest)?;
+
+ let err = ec_key.ecdsa_verify_cose(&signature, &sha256(MESSAGE2)?).unwrap_err();
+ let expected_err = Error::CallFailed(ApiName::ECDSA_verify, EcdsaError::BadSignature.into());
+ assert_eq!(expected_err, err);
+ Ok(())
+}
+
+#[test]
+fn verifying_ecdsa_cose_signed_as_der_fails() -> Result<()> {
+ let digest = sha256(MESSAGE1)?;
+ let mut ec_key = EcKey::new_p256()?;
+ ec_key.generate_key()?;
+
+ let signature = ec_key.ecdsa_sign_cose(&digest)?;
+ let err = ec_key.ecdsa_verify_der(&signature, &digest).unwrap_err();
+ let expected_err = Error::CallFailed(ApiName::ECDSA_verify, EcdsaError::BadSignature.into());
+ assert_eq!(expected_err, err);
+ Ok(())
+}