Unverified Commit 27c3b01a authored by Steven Fackler's avatar Steven Fackler Committed by GitHub
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Merge pull request #747 from BrianOn99/symm

Symm documentation
parents f79d92dd 75e6db6f
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//! High level interface to certain symmetric ciphers.
//!
//! # Examples
//!
//! Encrypt data in AES128 CBC mode
//!
//! ```
//! use openssl::symm::{encrypt, Cipher};
//!
//! let cipher = Cipher::aes_128_cbc();
//! let data = b"Some Crypto Text";
//! let key = b"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F";
//! let iv = b"\x00\x01\x02\x03\x04\x05\x06\x07\x00\x01\x02\x03\x04\x05\x06\x07";
//! let ciphertext = encrypt(
//!     cipher,
//!     key,
//!     Some(iv),
//!     data).unwrap();
//!
//! assert_eq!(
//!     b"\xB4\xB9\xE7\x30\xD6\xD6\xF7\xDE\x77\x3F\x1C\xFF\xB3\x3E\x44\x5A\x91\xD7\x27\x62\x87\x4D\
//!       \xFB\x3C\x5E\xC4\x59\x72\x4A\xF4\x7C\xA1",
//!     &ciphertext[..]);
//! ```
use std::cmp;
use std::ptr;
use libc::c_int;
@@ -12,6 +36,11 @@ pub enum Mode {
    Decrypt,
}

/// Represents a particular cipher algorithm.
///
/// See OpenSSL doc at [`EVP_EncryptInit`] for more information on each algorithms.
///
/// [`EVP_EncryptInit`]: https://www.openssl.org/docs/man1.1.0/crypto/EVP_EncryptInit.html
#[derive(Copy, Clone)]
pub struct Cipher(*const ffi::EVP_CIPHER);

@@ -153,17 +182,78 @@ impl Cipher {
}

/// Represents a symmetric cipher context.
///
/// Padding is enabled by default.
///
/// # Examples
///
/// Encrypt some plaintext in chunks, then decrypt the ciphertext back into plaintext, in AES 128
/// CBC mode.
///
/// ```
/// use openssl::symm::{Cipher, Mode, Crypter};
///
/// let plaintexts: [&[u8]; 2] = [b"Some Stream of", b" Crypto Text"];
/// let key = b"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F";
/// let iv = b"\x00\x01\x02\x03\x04\x05\x06\x07\x00\x01\x02\x03\x04\x05\x06\x07";
/// let data_len = plaintexts.iter().fold(0, |sum, x| sum + x.len());
///
/// // Create a cipher context for encryption.
/// let mut encrypter = Crypter::new(
///     Cipher::aes_128_cbc(),
///     Mode::Encrypt,
///     key,
///     Some(iv)).unwrap();
///
/// let block_size = Cipher::aes_128_cbc().block_size();
/// let mut ciphertext = vec![0; data_len + block_size];
///
/// // Encrypt 2 chunks of plaintexts successively.
/// let mut count = encrypter.update(plaintexts[0], &mut ciphertext).unwrap();
/// count += encrypter.update(plaintexts[1], &mut ciphertext[count..]).unwrap();
/// count += encrypter.finalize(&mut ciphertext[count..]).unwrap();
/// ciphertext.truncate(count);
///
/// assert_eq!(
///     b"\x0F\x21\x83\x7E\xB2\x88\x04\xAF\xD9\xCC\xE2\x03\x49\xB4\x88\xF6\xC4\x61\x0E\x32\x1C\xF9\
///       \x0D\x66\xB1\xE6\x2C\x77\x76\x18\x8D\x99",
///     &ciphertext[..]
/// );
///
///
/// // Let's pretend we don't know the plaintext, and now decrypt the ciphertext.
/// let data_len = ciphertext.len();
/// let ciphertexts = [&ciphertext[..9], &ciphertext[9..]];
///
/// // Create a cipher context for decryption.
/// let mut decrypter = Crypter::new(
///     Cipher::aes_128_cbc(),
///     Mode::Decrypt,
///     key,
///     Some(iv)).unwrap();
/// let mut plaintext = vec![0; data_len + block_size];
///
/// // Decrypt 2 chunks of ciphertexts successively.
/// let mut count = decrypter.update(ciphertexts[0], &mut plaintext).unwrap();
/// count += decrypter.update(ciphertexts[1], &mut plaintext[count..]).unwrap();
/// count += decrypter.finalize(&mut plaintext[count..]).unwrap();
/// plaintext.truncate(count);
///
/// assert_eq!(b"Some Stream of Crypto Text", &plaintext[..]);
/// ```
pub struct Crypter {
    ctx: *mut ffi::EVP_CIPHER_CTX,
    block_size: usize,
}

impl Crypter {
    /// Creates a new `Crypter`.
    /// Creates a new `Crypter`.  The initialisation vector, `iv`, is not necesarry for certain
    /// types of `Cipher`.
    ///
    /// # Panics
    ///
    /// Panics if an IV is required by the cipher but not provided.
    /// Panics if an IV is required by the cipher but not provided.  Also make sure that the key
    /// and IV size are appropriate for your cipher.
    pub fn new(
        t: Cipher,
        mode: Mode,
@@ -358,8 +448,36 @@ impl Drop for Crypter {
    }
}

/// Encrypts data, using the specified crypter type in encrypt mode with the
/// specified key and iv; returns the resulting (encrypted) data.
/// Encrypts data in one go, and returns the encrypted data.
///
/// Data is encrypted using the specified cipher type `t` in encrypt mode with the specified `key`
/// and initailization vector `iv`.
///
/// This is a convenient interface to `Crypter` to encrypt all data in one go.  To encrypt a stream
/// of data increamentally , use `Crypter` instead.
///
/// # Examples
///
/// Encrypt data in AES128 CBC mode
///
/// ```
/// use openssl::symm::{encrypt, Cipher};
///
/// let cipher = Cipher::aes_128_cbc();
/// let data = b"Some Crypto Text";
/// let key = b"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F";
/// let iv = b"\x00\x01\x02\x03\x04\x05\x06\x07\x00\x01\x02\x03\x04\x05\x06\x07";
/// let ciphertext = encrypt(
///     cipher,
///     key,
///     Some(iv),
///     data).unwrap();
///
/// assert_eq!(
///     b"\xB4\xB9\xE7\x30\xD6\xD6\xF7\xDE\x77\x3F\x1C\xFF\xB3\x3E\x44\x5A\x91\xD7\x27\x62\x87\x4D\
///       \xFB\x3C\x5E\xC4\x59\x72\x4A\xF4\x7C\xA1",
///     &ciphertext[..]);
/// ```
pub fn encrypt(
    t: Cipher,
    key: &[u8],
@@ -369,8 +487,36 @@ pub fn encrypt(
    cipher(t, Mode::Encrypt, key, iv, data)
}

/// Decrypts data, using the specified crypter type in decrypt mode with the
/// specified key and iv; returns the resulting (decrypted) data.
/// Decrypts data in one go, and returns the decrypted data.
///
/// Data is decrypted using the specified cipher type `t` in decrypt mode with the specified `key`
/// and initailization vector `iv`.
///
/// This is a convenient interface to `Crypter` to decrypt all data in one go.  To decrypt a  stream
/// of data increamentally , use `Crypter` instead.
///
/// # Examples
///
/// Decrypt data in AES256 ECB mode
///
/// ```
/// use openssl::symm::{decrypt, Cipher};
///
/// let cipher = Cipher::aes_128_cbc();
/// let data = b"\xB4\xB9\xE7\x30\xD6\xD6\xF7\xDE\x77\x3F\x1C\xFF\xB3\x3E\x44\x5A\x91\xD7\x27\x62\
///              \x87\x4D\xFB\x3C\x5E\xC4\x59\x72\x4A\xF4\x7C\xA1";
/// let key = b"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F";
/// let iv = b"\x00\x01\x02\x03\x04\x05\x06\x07\x00\x01\x02\x03\x04\x05\x06\x07";
/// let ciphertext = decrypt(
///     cipher,
///     key,
///     Some(iv),
///     data).unwrap();
///
/// assert_eq!(
///     b"Some Crypto Text",
///     &ciphertext[..]);
/// ```
pub fn decrypt(
    t: Cipher,
    key: &[u8],