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use getrandom;
use std::convert::AsRef;
use std::fmt;
mod b64;
mod bcrypt;
mod errors;
pub use crate::bcrypt::bcrypt;
pub use crate::errors::{BcryptError, BcryptResult};
const MIN_COST: u32 = 4;
const MAX_COST: u32 = 31;
pub const DEFAULT_COST: u32 = 12;
#[derive(Debug, PartialEq)]
pub struct HashParts {
cost: u32,
salt: String,
hash: String,
}
pub enum Version {
TwoA,
TwoX,
TwoY,
TwoB,
}
impl HashParts {
fn format(self) -> String {
self.format_for_version(Version::TwoB)
}
fn format_for_version(&self, version: Version) -> String {
format!("${}${:02}${}{}", version, self.cost, self.salt, self.hash)
}
}
impl ToString for HashParts {
fn to_string(&self) -> String {
self.format_for_version(Version::TwoY)
}
}
impl fmt::Display for Version {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let str = match self {
Version::TwoA => "2a",
Version::TwoB => "2b",
Version::TwoX => "2x",
Version::TwoY => "2y",
};
write!(f, "{}", str)
}
}
fn _hash_password(password: &[u8], cost: u32, salt: &[u8]) -> BcryptResult<HashParts> {
if cost > MAX_COST || cost < MIN_COST {
return Err(BcryptError::CostNotAllowed(cost));
}
if password.contains(&0u8) {
return Err(BcryptError::InvalidPassword);
}
let mut output = [0u8; 24];
let mut vec: Vec<u8> = Vec::new();
vec.extend_from_slice(password);
vec.push(0);
let truncated = if vec.len() > 72 { &vec[..72] } else { &vec };
bcrypt::bcrypt(cost, salt, truncated, &mut output);
Ok(HashParts {
cost,
salt: b64::encode(salt),
hash: b64::encode(&output[..23]),
})
}
fn split_hash(hash: &str) -> BcryptResult<HashParts> {
let mut parts = HashParts {
cost: 0,
salt: "".to_string(),
hash: "".to_string(),
};
let raw_parts: Vec<_> = hash.split('$').filter(|s| !s.is_empty()).collect();
if raw_parts.len() != 3 {
return Err(BcryptError::InvalidHash(hash.to_string()));
}
if raw_parts[0] != "2y" && raw_parts[0] != "2b" && raw_parts[0] != "2a" {
return Err(BcryptError::InvalidPrefix(raw_parts[0].to_string()));
}
if let Ok(c) = raw_parts[1].parse::<u32>() {
parts.cost = c;
} else {
return Err(BcryptError::InvalidCost(raw_parts[1].to_string()));
}
if raw_parts[2].len() == 53 {
parts.salt = raw_parts[2][..22].chars().collect();
parts.hash = raw_parts[2][22..].chars().collect();
} else {
return Err(BcryptError::InvalidHash(hash.to_string()));
}
Ok(parts)
}
pub fn hash<P: AsRef<[u8]>>(password: P, cost: u32) -> BcryptResult<String> {
hash_with_result(password, cost).map(|r| r.format())
}
pub fn hash_with_result<P: AsRef<[u8]>>(password: P, cost: u32) -> BcryptResult<HashParts> {
let salt = {
let mut s = [0u8; 16];
getrandom::getrandom(&mut s).expect("An error occurred");
s
};
_hash_password(password.as_ref(), cost, salt.as_ref())
}
pub fn verify<P: AsRef<[u8]>>(password: P, hash: &str) -> BcryptResult<bool> {
let parts = split_hash(hash)?;
let salt = b64::decode(&parts.salt)?;
let generated = _hash_password(password.as_ref(), parts.cost, &salt)?;
let source_decoded = b64::decode(&parts.hash)?;
let generated_decoded = b64::decode(&generated.hash)?;
if source_decoded.len() != generated_decoded.len() {
return Ok(false);
}
for (a, b) in source_decoded.into_iter().zip(generated_decoded) {
if a != b {
return Ok(false);
}
}
Ok(true)
}
#[cfg(test)]
mod tests {
use super::{
_hash_password, hash, split_hash, verify, BcryptError, BcryptResult, HashParts, Version,
DEFAULT_COST,
};
use quickcheck::{quickcheck, TestResult};
use std::iter;
#[test]
fn can_split_hash() {
let hash = "$2y$12$L6Bc/AlTQHyd9liGgGEZyOFLPHNgyxeEPfgYfBCVxJ7JIlwxyVU3u";
let output = split_hash(hash).unwrap();
let expected = HashParts {
cost: 12,
salt: "L6Bc/AlTQHyd9liGgGEZyO".to_string(),
hash: "FLPHNgyxeEPfgYfBCVxJ7JIlwxyVU3u".to_string(),
};
assert_eq!(output, expected);
}
#[test]
fn can_verify_hash_generated_from_some_online_tool() {
let hash = "$2a$04$UuTkLRZZ6QofpDOlMz32MuuxEHA43WOemOYHPz6.SjsVsyO1tDU96";
assert!(verify("password", hash).unwrap());
}
#[test]
fn can_verify_hash_generated_from_python() {
let hash = "$2b$04$EGdrhbKUv8Oc9vGiXX0HQOxSg445d458Muh7DAHskb6QbtCvdxcie";
assert!(verify("correctbatteryhorsestapler", hash).unwrap());
}
#[test]
fn can_verify_hash_generated_from_node() {
let hash = "$2a$04$n4Uy0eSnMfvnESYL.bLwuuj0U/ETSsoTpRT9GVk5bektyVVa5xnIi";
assert!(verify("correctbatteryhorsestapler", hash).unwrap());
}
#[test]
fn a_wrong_password_is_false() {
let hash = "$2b$04$EGdrhbKUv8Oc9vGiXX0HQOxSg445d458Muh7DAHskb6QbtCvdxcie";
assert!(!verify("wrong", hash).unwrap());
}
#[test]
fn errors_with_invalid_hash() {
let hash = "$2a$04$n4Uy0eSnMfvnESYL.bLwuuj0U/ETSsoTpRT9GVk$5bektyVVa5xnIi";
assert!(verify("correctbatteryhorsestapler", hash).is_err());
}
#[test]
fn errors_with_non_number_cost() {
let hash = "$2a$ab$n4Uy0eSnMfvnESYL.bLwuuj0U/ETSsoTpRT9GVk$5bektyVVa5xnIi";
assert!(verify("correctbatteryhorsestapler", hash).is_err());
}
#[test]
fn errors_with_a_hash_too_long() {
let hash = "$2a$04$n4Uy0eSnMfvnESYL.bLwuuj0U/ETSsoTpRT9GVk$5bektyVVa5xnIerererereri";
assert!(verify("correctbatteryhorsestapler", hash).is_err());
}
#[test]
fn can_verify_own_generated() {
let hashed = hash("hunter2", 4).unwrap();
assert_eq!(true, verify("hunter2", &hashed).unwrap());
}
#[test]
fn long_passwords_truncate_correctly() {
let hash = "$2a$05$......................YgIDy4hFBdVlc/6LHnD9mX488r9cLd2";
assert!(verify(iter::repeat("x").take(100).collect::<String>(), hash).unwrap());
}
#[test]
fn generate_versions() {
let password = "hunter2".as_bytes();
let salt = vec![0; 16];
let result = _hash_password(password, DEFAULT_COST, salt.as_slice()).unwrap();
assert_eq!(
"$2a$12$......................21jzCB1r6pN6rp5O2Ev0ejjTAboskKm",
result.format_for_version(Version::TwoA)
);
assert_eq!(
"$2b$12$......................21jzCB1r6pN6rp5O2Ev0ejjTAboskKm",
result.format_for_version(Version::TwoB)
);
assert_eq!(
"$2x$12$......................21jzCB1r6pN6rp5O2Ev0ejjTAboskKm",
result.format_for_version(Version::TwoX)
);
assert_eq!(
"$2y$12$......................21jzCB1r6pN6rp5O2Ev0ejjTAboskKm",
result.format_for_version(Version::TwoY)
);
let hash = result.to_string();
assert_eq!(true, verify("hunter2", &hash).unwrap());
}
#[test]
fn forbid_null_bytes() {
fn assert_invalid_password(password: &[u8]) {
match hash(password, DEFAULT_COST) {
Ok(_) => panic!(format!(
"NULL bytes must be forbidden, but {:?} is allowed.",
password
)),
Err(BcryptError::InvalidPassword) => {}
Err(e) => panic!(format!(
"NULL bytes are forbidden but error differs: {} for {:?}.",
e, password
)),
}
}
assert_invalid_password("\0".as_bytes());
assert_invalid_password("\0\0\0\0\0\0\0\0".as_bytes());
assert_invalid_password("passw0rd\0".as_bytes());
assert_invalid_password("passw0rd\0with tail".as_bytes());
assert_invalid_password("\0passw0rd".as_bytes());
}
quickcheck! {
fn can_verify_arbitrary_own_generated(pass: Vec<u8>) -> BcryptResult<bool> {
let mut pass = pass;
pass.retain(|&b| b != 0);
let hashed = hash(&pass, 4)?;
verify(pass, &hashed)
}
fn doesnt_verify_different_passwords(a: Vec<u8>, b: Vec<u8>) -> BcryptResult<TestResult> {
let mut a = a;
a.retain(|&b| b != 0);
let mut b = b;
b.retain(|&b| b != 0);
if a == b {
return Ok(TestResult::discard());
}
let hashed = hash(a, 4)?;
Ok(TestResult::from_bool(!verify(b, &hashed)?))
}
}
}