Disable automatic padding.

[crypto_lab1.git] / src / crypto.rs

diff --git a/src/crypto.rs b/src/crypto.rs
index ce301ab..35c7b48 100644 (file)
--- a/src/crypto.rs
+++ b/src/crypto.rs
@@ -12,16 +12,34 @@ pub fn compute_mac(data: &[u8]) -> [u8, ..10] {
    let mut hmac = HMAC(SHA256, KEY_A);
    hmac.update(data);
    let mut result = [0u8, ..10];
-   copy_memory(&mut result, hmac.finalize().slice(0, 9));
+   copy_memory(&mut result, hmac.finalize().slice(0, 10));
    result
 }
 
-pub fn encrypt(plaindata: &[u8], iv: &[u8]) -> Vec<u8> {
-   symm::encrypt(symm::AES_256_CBC, KEY_C, iv.to_vec(), plaindata)
+pub fn encrypt(plaindata: &[u8], iv: &[u8]) -> Option<Vec<u8>> {
+   let c = symm::Crypter::new(symm::AES_256_CBC);
+   c.init(symm::Encrypt, KEY_C, iv.to_vec());
+   c.pad(false); // Padding disabled!
+   let mut r = c.update(plaindata);
+   let rest = c.finalize();
+   if rest.is_empty() {
+      Some(r)
+   } else {
+      None
+   }
 }
 
-pub fn decrypt(cypherdata: &[u8], iv: &[u8]) -> Vec<u8> {
-   symm::decrypt(symm::AES_256_CBC, KEY_C, iv.to_vec(), cypherdata)
+pub fn decrypt(cypherdata: &[u8], iv: &[u8]) -> Option<Vec<u8>> {
+   let c = symm::Crypter::new(symm::AES_256_CBC);
+   c.init(symm::Decrypt, KEY_C, iv.to_vec());
+   c.pad(false); // Padding disabled!
+   let mut r = c.update(cypherdata);
+   let rest = c.finalize();
+   if rest.is_empty() {
+      Some(r)
+   } else {
+      None
+   }
 }
 
 pub fn generate_key(size_byte: uint) -> IoResult<Vec<u8>>  {