From d47ca7fa5437e879b25f5b77e17f83118c4f1b51 Mon Sep 17 00:00:00 2001
From: Julien Cretin <cretin@google.com>
Date: Fri, 21 Jan 2022 18:01:10 +0100
Subject: [PATCH] Add documentation

---
 libraries/crypto/src/cbc.rs | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/libraries/crypto/src/cbc.rs b/libraries/crypto/src/cbc.rs
index 8c56c45..03ee39b 100644
--- a/libraries/crypto/src/cbc.rs
+++ b/libraries/crypto/src/cbc.rs
@@ -16,8 +16,13 @@ use super::util::{xor_block_16, Block16};
 use crate::aes256::{DecryptionKey, EncryptionKey};
 use core::convert::TryInto;
 
-pub fn cbc_encrypt(key: &EncryptionKey, mut iv: Block16, blocks: &mut [u8]) {
-    for block in blocks.chunks_mut(16) {
+/// Encrypts a byte slice.
+///
+/// # Panics
+///
+/// Panics if the byte slice is not a multiple of the block size (16 bytes).
+pub fn cbc_encrypt(key: &EncryptionKey, mut iv: Block16, bytes: &mut [u8]) {
+    for block in bytes.chunks_mut(16) {
         let block: &mut Block16 = block.try_into().unwrap();
         xor_block_16(block, &iv);
         key.encrypt_block(block);
@@ -25,8 +30,13 @@ pub fn cbc_encrypt(key: &EncryptionKey, mut iv: Block16, blocks: &mut [u8]) {
     }
 }
 
-pub fn cbc_decrypt(key: &DecryptionKey, mut iv: Block16, blocks: &mut [u8]) {
-    for block in blocks.chunks_mut(16) {
+/// Decrypts a byte slice.
+///
+/// # Panics
+///
+/// Panics if the byte slice is not a multiple of the block size (16 bytes).
+pub fn cbc_decrypt(key: &DecryptionKey, mut iv: Block16, bytes: &mut [u8]) {
+    for block in bytes.chunks_mut(16) {
         let block: &mut Block16 = block.try_into().unwrap();
         let tmp = *block;
         key.decrypt_block(block);