feat(common): add signed messages recording in 'FakeKesSigner'

Author: jpraynaud

mithril-common/src/test/crypto_helper/cardano/kes/signer_fake.rs

@@ -16,16 +16,24 @@ type KesSignatureResult = StdResult<(Sum6KesSig, OpCert)>;
 /// Fake KES Signer implementation.
 pub struct KesSignerFake {
     results: Mutex<VecDeque<KesSignatureResult>>,
+    signed_messages: Mutex<VecDeque<Vec<u8>>>,
 }
 
 impl KesSignerFake {
     /// Creates a new `KesSignerFake` instance.
     pub fn new(results: Vec<KesSignatureResult>) -> Self {
         Self {
             results: Mutex::new(results.into()),
+            signed_messages: Mutex::new(VecDeque::new()),
         }
     }
 
+    /// Returns the messages that were requested to be signed
+    pub fn get_signed_messages(&self) -> Vec<Vec<u8>> {
+        let messages = self.signed_messages.lock().unwrap();
+        messages.iter().cloned().collect()
+    }
+
     /// Returns a dummy signature result that is always successful.
     pub fn dummy_signature(test_directory: &str) -> (Sum6KesSig, OpCert) {
         let KesCryptographicMaterialForTest {
@@ -55,7 +63,10 @@ impl KesSignerFake {
 }
 
 impl KesSigner for KesSignerFake {
-    fn sign(&self, _message: &[u8], _kes_period: KesPeriod) -> KesSignatureResult {
+    fn sign(&self, message: &[u8], _kes_period: KesPeriod) -> KesSignatureResult {
+        let mut messages = self.signed_messages.lock().unwrap();
+        messages.push_back(message.to_vec());
+
         let mut results = self.results.lock().unwrap();
 
         results.pop_front().unwrap()
@@ -77,25 +88,29 @@ mod tests {
             0 as KesPeriod,
             "fake_kes_signer_returns_signature_batches_in_expected_order",
         );
-        let message = b"Test message for KES signing";
+        let message1 = b"Test message 1 for KES signing";
         let kes_signer = KesSignerStandard::new(kes_secret_key_file, operational_certificate_file);
         let kes_signing_period = 1;
         let (kes_signature, op_cert) = kes_signer
-            .sign(message, kes_signing_period)
+            .sign(message1, kes_signing_period)
             .expect("Signing should not fail");
         let fake_kes_signer = KesSignerFake::new(vec![
             Ok((kes_signature, op_cert.clone())),
             Err(anyhow::anyhow!("Fake error")),
         ]);
 
         let (kes_signature_1, op_cert_1) = fake_kes_signer
-            .sign(message, kes_signing_period)
+            .sign(message1, kes_signing_period)
             .expect("Signing should not fail");
         assert_eq!(kes_signature, kes_signature_1);
         assert_eq!(op_cert, op_cert_1);
 
+        let message2 = b"Test message 2 for KES signing";
         fake_kes_signer
-            .sign(message, kes_signing_period)
+            .sign(message2, kes_signing_period)
             .expect_err("Signing should fail");
+
+        let signed_messages = fake_kes_signer.get_signed_messages();
+        assert_eq!(vec![message1.to_vec(), message2.to_vec()], signed_messages);
     }
 }