Function orion::default::chacha20_decrypt[−][src]

pub fn chacha20_decrypt(
    key: &[u8], 
    ciphertext: &[u8]
) -> Result<Vec<u8>, UnknownCryptoError>

IETF ChaCha20 decryption.

About:

  • The initial counter is set to 0
  • The ciphertext passed must be of the same format as the one returned by default::chacha20_encrypt()

Parameters:

  • ciphertext: The data to be decrypted with the first 12 bytes being the nonce
  • key: The secret key used to decrypt the ciphertext

Security:

This does not provide any data integrity. If you need data integrity, you should be using a ChaCha20_Poly1305 construct instead. In most cases you would want data integrity. See RFC for more information.

Exceptions:

An exception will be thrown if:

  • key is not 32 bytes
  • ciphertext is less than 13 bytes
  • ciphertext is longer than (2^32)-14

Example:

use orion::default;
use orion::utilities::util;

let mut key = [0u8; 32]; // Replace this with the key used for decryption
util::gen_rand_key(&mut key).unwrap();

// Sample encrypted data where the first 12 bytes are the nonce
let ciphertext = "VRjKWpyfx9p6YynWFgAvCM/ithgwXaRptiljrQDXWEI".as_bytes();

let decrypted_data = default::chacha20_decrypt(&key, ciphertext).unwrap();