Added invalid signing key self test.

libcrux-ml-dsa/tests/self.rs

@@ -1,3 +1,4 @@
+use libcrux_ml_dsa::{ml_dsa_44, ml_dsa_65, ml_dsa_87};
 use rand::{rngs::OsRng, RngCore};
 
 fn random_array<const L: usize>() -> [u8; L] {
@@ -6,16 +7,34 @@ fn random_array<const L: usize>() -> [u8; L] {
     rng.try_fill_bytes(&mut seed).unwrap();
     seed
 }
+fn random_message() -> Vec<u8> {
+    let mut rng = OsRng;
+
+    let mut length = [0u8; 2];
+    rng.try_fill_bytes(&mut length).unwrap();
+    let length = ((length[1] as u16) << 8) | length[0] as u16;
+
+    let mut message = Vec::with_capacity(length.into());
+    rng.try_fill_bytes(&mut message).unwrap();
+
+    message
+}
+
+fn modify_signing_key<const SIGNING_KEY_SIZE: usize>(signing_key: &mut [u8; SIGNING_KEY_SIZE]) {
+    // TODO: See if we can make it more dynamic than this.
+    for byte in signing_key[128..].iter_mut() {
+        *byte = 1;
+    }
+}
 
-macro_rules! impl_consistency {
+macro_rules! impl_consistency_test {
     ($name:ident, $key_gen:expr, $sign:expr, $verify:expr) => {
         #[test]
         fn $name() {
             let key_generation_seed = random_array();
             let signing_randomness = random_array();
 
-            // TODO: Choose the length randomly
-            let message = random_array::<94883>();
+            let message = random_message();
 
             let key_pair = $key_gen(key_generation_seed);
 
@@ -27,23 +46,63 @@ macro_rules! impl_consistency {
     };
 }
 
-impl_consistency!(
+macro_rules! impl_invalid_signing_key_test {
+    ($name:ident, $key_gen:expr, $signing_key_size: expr, $sign:expr, $verify:expr) => {
+        #[test]
+        fn $name() {
+            let key_generation_seed = random_array();
+            let signing_randomness = random_array();
+
+            let message = random_message();
+
+            let mut key_pair = $key_gen(key_generation_seed);
+
+            modify_signing_key::<{ $signing_key_size }>(&mut key_pair.signing_key.0);
+
+            let signature = $sign(key_pair.signing_key, &message, signing_randomness);
+
+            assert!($verify(key_pair.verification_key, &message, signature).is_err());
+        }
+    };
+}
+
+impl_consistency_test!(
     consistency_44,
-    libcrux_ml_dsa::ml_dsa_44::generate_key_pair,
-    libcrux_ml_dsa::ml_dsa_44::sign,
-    libcrux_ml_dsa::ml_dsa_44::verify
+    ml_dsa_44::generate_key_pair,
+    ml_dsa_44::sign,
+    ml_dsa_44::verify
 );
-
-impl_consistency!(
+impl_consistency_test!(
     consistency_65,
-    libcrux_ml_dsa::ml_dsa_65::generate_key_pair,
-    libcrux_ml_dsa::ml_dsa_65::sign,
-    libcrux_ml_dsa::ml_dsa_65::verify
+    ml_dsa_65::generate_key_pair,
+    ml_dsa_65::sign,
+    ml_dsa_65::verify
 );
-
-impl_consistency!(
+impl_consistency_test!(
     consistency_87,
-    libcrux_ml_dsa::ml_dsa_87::generate_key_pair,
-    libcrux_ml_dsa::ml_dsa_87::sign,
-    libcrux_ml_dsa::ml_dsa_87::verify
+    ml_dsa_87::generate_key_pair,
+    ml_dsa_87::sign,
+    ml_dsa_87::verify
+);
+
+impl_invalid_signing_key_test!(
+    invalid_signing_key_44,
+    ml_dsa_44::generate_key_pair,
+    ml_dsa_44::SIGNING_KEY_SIZE,
+    ml_dsa_44::sign,
+    ml_dsa_44::verify
+);
+impl_invalid_signing_key_test!(
+    invalid_signing_key_65,
+    ml_dsa_65::generate_key_pair,
+    ml_dsa_65::SIGNING_KEY_SIZE,
+    ml_dsa_65::sign,
+    ml_dsa_65::verify
+);
+impl_invalid_signing_key_test!(
+    invalid_signing_key_87,
+    ml_dsa_87::generate_key_pair,
+    ml_dsa_87::SIGNING_KEY_SIZE,
+    ml_dsa_87::sign,
+    ml_dsa_87::verify
 );