// Copyright 2022 Adobe. All rights reserved.
// This file is licensed to you under the Apache License,
// Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
// or the MIT license (http://opensource.org/licenses/MIT),
// at your option.
// Unless required by applicable law or agreed to in writing,
// this software is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR REPRESENTATIONS OF ANY KIND, either express or
// implied. See the LICENSE-MIT and LICENSE-APACHE files for the
// specific language governing permissions and limitations under
// each license.
/// The Saltgenerator trait always the caller to supply
/// a funtion to generate a salt value used when hashing
/// data. Providing a unique salt ensures a unique hash for
/// a given data set.
pub trait SaltGenerator {
/// generate a salt vector
fn generate_salt(&self) -> Option<Vec<u8>>;
}
/// NoSalt return a no salt option to a function
pub struct NoSalt {}
impl SaltGenerator for NoSalt {
fn generate_salt(&self) -> Option<Vec<u8>> {
None
}
}
/// const NoSalt instance that can be used when no salting is required
pub const NO_SALT: &NoSalt = &NoSalt {};
/// Default salt generator
/// This generator uses OpenSSL to generate a
/// salt of the specified length (default 16 bytes)
pub struct DefaultSalt {
salt_len: usize,
}
impl DefaultSalt {
/// Set the length of the generated salt vector
#[allow(dead_code)]
pub fn set_salt_length(&mut self, len: usize) {
self.salt_len = len;
}
}
impl Default for DefaultSalt {
fn default() -> Self {
DefaultSalt { salt_len: 16 }
}
}
impl SaltGenerator for DefaultSalt {
fn generate_salt(&self) -> Option<Vec<u8>> {
#[cfg(feature = "file_io")] // auto generation not supported on wasm
{
let mut salt = vec![0; self.salt_len];
openssl::rand::rand_bytes(&mut salt).ok()?;
Some(salt)
}
#[cfg(not(feature = "file_io"))]
{
None
}
}
}