diff --git a/openssl/src/aes.rs b/openssl/src/aes.rs index 40546f59..5be99430 100644 --- a/openssl/src/aes.rs +++ b/openssl/src/aes.rs @@ -1,15 +1,62 @@ -//! Low level AES functionality +//! Low level AES IGE functionality //! -//! The `symm` module should be used in preference to this module in most cases. +//! AES ECB, CBC, XTS, CTR, CFB, GCM and other conventional symmetric encryption +//! modes are found in [`symm`]. This is the implementation of AES IGE. +//! +//! Advanced Encryption Standard (AES) provides symmetric key cipher that +//! the same key is used to encrypt and decrypt data. This implementation +//! uses 128, 192, or 256 bit keys. This module provides functions to +//! create a new key with [`new_encrypt`] and perform an encryption/decryption +//! using that key with [`aes_ige`]. +//! +//! [`new_encrypt`]: struct.AesKey.html#method.new_encrypt +//! [`aes_ige`]: fn.aes_ige.html +//! +//! The [`symm`] module should be used in preference to this module in most cases. +//! The IGE block cypher is a non-traditional cipher mode. More traditional AES +//! encryption methods are found in the [`Crypter`] and [`Cipher`] structs. +//! +//! [`symm`]: ../symm/index.html +//! [`Crypter`]: ../symm/struct.Crypter.html +//! [`Cipher`]: ../symm/struct.Cipher.html +//! +//! # Examples +//! +//! ```rust +//! # extern crate openssl; +//! extern crate hex; +//! use openssl::aes::{AesKey, KeyError, aes_ige}; +//! use openssl::symm::Mode; +//! use hex::{FromHex, ToHex}; +//! +//! fn decrypt() -> Result<(), KeyError> { +//! let raw_key = "000102030405060708090A0B0C0D0E0F"; +//! let hex_cipher = "12345678901234561234567890123456"; +//! let randomness = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"; +//! if let (Ok(key_as_u8), Ok(cipher_as_u8), Ok(mut iv_as_u8)) = +//! (Vec::from_hex(raw_key), Vec::from_hex(hex_cipher), Vec::from_hex(randomness)) { +//! let key = AesKey::new_encrypt(&key_as_u8)?; +//! let mut output = vec![0u8; cipher_as_u8.len()]; +//! aes_ige(&cipher_as_u8, &mut output, &key, &mut iv_as_u8, Mode::Encrypt); +//! assert_eq!(output.to_hex(), "a6ad974d5cea1d36d2f367980907ed32"); +//! } +//! Ok(()) +//! } +//! +//! # fn main() { +//! # decrypt(); +//! # } use ffi; use std::mem; use libc::c_int; use symm::Mode; +/// Provides Error handling for parsing keys. #[derive(Debug)] pub struct KeyError(()); +/// The key used to encrypt or decrypt cipher blocks. pub struct AesKey(ffi::AES_KEY); impl AesKey { @@ -63,6 +110,18 @@ impl AesKey { /// Performs AES IGE encryption or decryption /// +/// AES IGE (Infinite Garble Extension) is a form of AES block cipher utilized in +/// OpenSSL. Infinite Garble referes to propogating forward errors. IGE, like other +/// block ciphers implemented for AES requires an initalization vector. The IGE mode +/// allows a stream of blocks to be encrypted or decrypted without having the entire +/// plaintext available. For more information, visit [AES IGE Encryption]. +/// +/// This block cipher uses 16 byte blocks. The rust implmentation will panic +/// if the input or output does not meet this 16-byte boundry. Attention must +/// be made in this low level implementation to pad the value to the 128-bit boundry. +/// +/// [AES IGE Encryption]: http://www.links.org/files/openssl-ige.pdf +/// /// # Panics /// /// Panics if `in_` is not the same length as `out`, if that length is not a multiple of 16, or if