also implement encrypting in cbc mode

2 files changed, 49 insertions, 0 deletions

diff --git a/src/aes.rs b/src/aes.rs
index 3ff9850..eb281e2 100644
--- a/src/aes.rs
+++ b/src/aes.rs
@@ -28,6 +28,30 @@ pub fn decrypt_aes_128_cbc (bytes: &[u8], key: &[u8], iv: &[u8]) -> Vec<u8> {
     return unpad_pkcs7(&plaintext[..]).to_vec();
 }
 
+pub fn encrypt_aes_128_ecb (bytes: &[u8], key: &[u8]) -> Vec<u8> {
+    return openssl::crypto::symm::encrypt(
+        openssl::crypto::symm::Type::AES_128_ECB,
+        key,
+        vec![],
+        bytes
+    )
+}
+
+pub fn encrypt_aes_128_cbc (bytes: &[u8], key: &[u8], iv: &[u8]) -> Vec<u8> {
+    let mut prev = iv.to_vec();
+    let mut ciphertext = vec![];
+    for block in bytes.chunks(16) {
+        let plaintext_block = fixed_xor(&pad_pkcs7(block, 16)[..], &prev[..]);
+        let mut ciphertext_block = encrypt_aes_128_ecb(&plaintext_block[..], key);
+        ciphertext_block.truncate(16);
+        for &c in ciphertext_block.iter() {
+            ciphertext.push(c);
+        }
+        prev = ciphertext_block.clone();
+    }
+    return ciphertext;
+}
+
 pub fn find_aes_128_ecb_encrypted_string (inputs: &[Vec<u8>]) -> Vec<u8> {
     let mut max_dups = 0;
     let mut found = vec![];
@@ -46,3 +70,26 @@ pub fn find_aes_128_ecb_encrypted_string (inputs: &[Vec<u8>]) -> Vec<u8> {
     }
     return found;
 }
+
+#[test]
+fn test_encrypt_decrypt () {
+    let plaintext = b"Summertime and the wind is blowing outside in lower \
+                     Chelsea and I don't know what I'm doing in the city, the \
+                     sun is always in my eyes";
+    let key = b"YELLOW SUBMARINE";
+    let iv = [0; 16];
+
+    let ciphertext_ecb = encrypt_aes_128_ecb(&plaintext[..], &key[..]);
+    let ciphertext_cbc = encrypt_aes_128_cbc(&plaintext[..], &key[..], &iv[..]);
+
+    let plaintext2_ecb = decrypt_aes_128_ecb(&ciphertext_ecb[..], &key[..]);
+    let plaintext2_cbc = decrypt_aes_128_cbc(&ciphertext_cbc[..], &key[..], &iv[..]);
+
+    let ciphertext2_ecb = encrypt_aes_128_ecb(&plaintext2_ecb[..], &key[..]);
+    let ciphertext2_cbc = encrypt_aes_128_cbc(&plaintext2_cbc[..], &key[..], &iv[..]);
+
+    assert_eq!(plaintext, plaintext2_ecb);
+    assert_eq!(plaintext, plaintext2_cbc);
+    assert_eq!(ciphertext_ecb, ciphertext2_ecb);
+    assert_eq!(ciphertext_cbc, ciphertext2_cbc);
+}
diff --git a/src/lib.rs b/src/lib.rs
index 14e896a..901cbd6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,6 +9,8 @@ mod xor;
 
 pub use aes::decrypt_aes_128_ecb;
 pub use aes::decrypt_aes_128_cbc;
+pub use aes::encrypt_aes_128_ecb;
+pub use aes::encrypt_aes_128_cbc;
 pub use aes::find_aes_128_ecb_encrypted_string;
 pub use base64::to_base64;
 pub use primitives::fixed_xor;