Add authentication integration test

src/crypto.rs

@@ -60,7 +60,7 @@ pub struct EncryptionParams {
 }
 
 impl EncryptionParams {
-    fn get_params_len(&self) -> usize {
+    pub fn get_params_len(&self) -> usize {
         SALT_LEN + 4*2 + 2 + self.cipher.get_nonce_size()
     }
 

tests/authentication.rs

@@ -0,0 +1,51 @@
+use rand::Rng;
+use doby::{
+    crypto::{
+        ArgonParams,
+        CipherAlgorithm,
+        EncryptionParams,
+        DobyCipher,
+    },
+    encrypt,
+    decrypt,
+};
+
+fn different_elements<T: Eq>(v1: &Vec<T>, v2: &Vec<T>) -> usize {
+    assert_eq!(v1.len(), v2.len());
+    v1.into_iter().enumerate().filter(|x| v2[x.0] != *x.1).count()
+}
+
+#[test]
+fn authentication() {
+    const BLOCK_SIZE: usize = 65536;
+    const PLAINTEXT: &[u8; 13] = b"the plaintext";
+    const PASSWORD: &str = "the password";
+    let params = EncryptionParams::new(ArgonParams {
+        t_cost: 1,
+        m_cost: 8,
+        parallelism: 1,
+    }, CipherAlgorithm::AesCtr);
+
+    let encrypter = DobyCipher::new(PASSWORD.into(), &params).unwrap();
+    let mut ciphertext = Vec::with_capacity(PLAINTEXT.len()+158);
+    encrypt(&mut &PLAINTEXT[..], &mut ciphertext, &params, encrypter, BLOCK_SIZE, None).unwrap();
+    assert_eq!(ciphertext.len(), PLAINTEXT.len()+158);
+
+    for i in 0..ciphertext.len() {
+        let mut compromised = ciphertext.clone();
+        while compromised[i] == ciphertext[i] {
+            compromised[i] = rand::thread_rng().gen();
+        }
+        assert_eq!(different_elements(&compromised, &ciphertext), 1);
+        let decrypter = DobyCipher::new(PASSWORD.into(), &params).unwrap();
+        let mut decrypted = Vec::with_capacity(PLAINTEXT.len());
+        let verified = decrypt(&mut &compromised[..], &mut decrypted, decrypter, BLOCK_SIZE).unwrap();
+        assert_eq!(verified, false);
+    }
+
+    let decrypter = DobyCipher::new(PASSWORD.into(), &params).unwrap();
+    let mut decrypted = Vec::with_capacity(PLAINTEXT.len());
+    let verified = decrypt(&mut &ciphertext[4+params.get_params_len()..], &mut decrypted, decrypter, BLOCK_SIZE).unwrap();
+    assert_eq!(decrypted, PLAINTEXT);
+    assert_eq!(verified, true);
+}