vaultwarden/src/crypto.rs
Jeremy Lin 7d552dbdc8 Increase length limit for email token generation
The current limit of 19 is an artifact of the implementation, which can be
easily rewritten in terms of a more general string generation function.
The new limit is 255 (max value of a `u8`); using a larger type would
probably be overkill.
2022-01-24 01:17:00 -08:00

113 lines
3.2 KiB
Rust

//
// PBKDF2 derivation
//
use std::num::NonZeroU32;
use data_encoding::HEXLOWER;
use ring::{digest, hmac, pbkdf2};
static DIGEST_ALG: pbkdf2::Algorithm = pbkdf2::PBKDF2_HMAC_SHA256;
const OUTPUT_LEN: usize = digest::SHA256_OUTPUT_LEN;
pub fn hash_password(secret: &[u8], salt: &[u8], iterations: u32) -> Vec<u8> {
let mut out = vec![0u8; OUTPUT_LEN]; // Initialize array with zeros
let iterations = NonZeroU32::new(iterations).expect("Iterations can't be zero");
pbkdf2::derive(DIGEST_ALG, iterations, salt, secret, &mut out);
out
}
pub fn verify_password_hash(secret: &[u8], salt: &[u8], previous: &[u8], iterations: u32) -> bool {
let iterations = NonZeroU32::new(iterations).expect("Iterations can't be zero");
pbkdf2::verify(DIGEST_ALG, iterations, salt, secret, previous).is_ok()
}
//
// HMAC
//
pub fn hmac_sign(key: &str, data: &str) -> String {
let key = hmac::Key::new(hmac::HMAC_SHA1_FOR_LEGACY_USE_ONLY, key.as_bytes());
let signature = hmac::sign(&key, data.as_bytes());
HEXLOWER.encode(signature.as_ref())
}
//
// Random values
//
pub fn get_random_64() -> Vec<u8> {
get_random(vec![0u8; 64])
}
pub fn get_random(mut array: Vec<u8>) -> Vec<u8> {
use ring::rand::{SecureRandom, SystemRandom};
SystemRandom::new().fill(&mut array).expect("Error generating random values");
array
}
/// Generates a random string over a specified alphabet.
pub fn get_random_string(alphabet: &[u8], num_chars: usize) -> String {
// Ref: https://rust-lang-nursery.github.io/rust-cookbook/algorithms/randomness.html
use rand::Rng;
let mut rng = rand::thread_rng();
(0..num_chars)
.map(|_| {
let i = rng.gen_range(0..alphabet.len());
alphabet[i] as char
})
.collect()
}
/// Generates a random numeric string.
pub fn get_random_string_numeric(num_chars: usize) -> String {
const ALPHABET: &[u8] = b"0123456789";
get_random_string(ALPHABET, num_chars)
}
/// Generates a random alphanumeric string.
pub fn get_random_string_alphanum(num_chars: usize) -> String {
const ALPHABET: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZ\
abcdefghijklmnopqrstuvwxyz\
0123456789";
get_random_string(ALPHABET, num_chars)
}
pub fn generate_id(num_bytes: usize) -> String {
HEXLOWER.encode(&get_random(vec![0; num_bytes]))
}
pub fn generate_send_id() -> String {
// Send IDs are globally scoped, so make them longer to avoid collisions.
generate_id(32) // 256 bits
}
pub fn generate_attachment_id() -> String {
// Attachment IDs are scoped to a cipher, so they can be smaller.
generate_id(10) // 80 bits
}
/// Generates a numeric token for email-based verifications.
pub fn generate_email_token(token_size: u8) -> String {
get_random_string_numeric(token_size as usize)
}
/// Generates a personal API key.
/// Upstream uses 30 chars, which is ~178 bits of entropy.
pub fn generate_api_key() -> String {
get_random_string_alphanum(30)
}
//
// Constant time compare
//
pub fn ct_eq<T: AsRef<[u8]>, U: AsRef<[u8]>>(a: T, b: U) -> bool {
use ring::constant_time::verify_slices_are_equal;
verify_slices_are_equal(a.as_ref(), b.as_ref()).is_ok()
}