oath2

This library aims to provide implementations of HOTP, TOTP, and OCRA as specified by the RFCs. oath2 is a successor of oath library. I had to fork it, because avacariu doesn't react on PRs.

Implemented:

• HOTP (RFC 4226)
• TOTP (RFC 6238)
• OCRA (RFC 6287)

WARNING While ieee754 is broken, RAMP fails to compile. OCRA numeric question mode can't use long Int, it is forced to use u64 instead. This data type leads us to question length limitation: 19 symbols. Number must fit u64. For default challenge format (N08) it is more that enough.

Examples

HOTP

// htop(key, counter, digits)
// hotp_raw takes bytes as the key
assert_eq!(hotp_raw(b"\xff", 23, 6), 330795);
// hotp takes a hex string as the key
assert_eq!(hotp("ff", 23, 6), 330795);

hotp_custom(b"\xff", 23, 6, Sha1::new());

TOTP

All the times below are in seconds.

// totp(key, digits, epoch, time_step)
totp("ff", 6, 0, 30); // defaults for most TOTP implementations
totp_raw(b"\xff", 6, 0, 30);
// totp_custom(key, digits, epoch, time_step, current_time, hash)
totp_custom(b"\xff", 6, 0, 30, 255, Sha1::new());

OCRA

let NULL: &[u8] = &[];
let STANDARD_KEY_20: &[u8] = &[0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x30,
                               0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x30];
let STANDARD_KEY_32 = "12345678901234567890123456789012".as_bytes();
let STANDARD_KEY_64 = "1234567890123456789012345678901234567890123456789012345678901234".as_bytes();
let PIN_1234_SHA1: &[u8] = &[0x71, 0x10, 0xed, 0xa4, 0xd0, 0x9e, 0x06, 0x2a, 0xa5, 0xe4,
                             0xa3, 0x90, 0xb0, 0xa5, 0x72, 0xac, 0x0d, 0x2c, 0x02, 0x20];

let suite = "OCRA-1:HOTP-SHA1-6:QN08";
let result = ocra(&suite, &STANDARD_KEY_20, 0, "00000000", NULL, NULL, 0)
assert_eq!(result, Ok(237653));

// Attention! PIN must be already hashed!
let suite_c = "OCRA-1:HOTP-SHA256-8:C-QN08-PSHA1";
let result_c = ocra(&suite_c, &STANDARD_KEY_32, 8, "12345678", PIN_1234_SHA1, NULL, 0);
assert_eq!(result_c, Ok(75011558));

let suite_t = "OCRA-1:HOTP-SHA512-8:QN08-T1M";
let t = 1_206_446_760; // UTC time in seconds
let result_t = ocra(&suite, &STANDARD_KEY_64, 18, "22222222", NULL, NULL, t);
assert_eq!(result_t, Ok(22048402));

Google Authenticator

Keys provided by Google are encoded using base32. You'll need to convert them before passing them to any of the functions in this crate.

A simple way to do this is using the base32 crate.

// assuming AAAAAAAAAAAAAAAA is your key
base32::decode(base32::Alphabet::RFC4648 {padding: false}, "AAAAAAAAAAAAAAAA").unwrap().as_ref()

And pass the result of that as the key parameter to the HOTP and TOTP functions.

Misc

If you don't want to use rustc-serialize directly, this library provides a wrapper around from_hex(). This helps with the functions that expect byte arrays.

let seed = oath::from_hex("ff").unwrap();
totp_raw(seed.as_slice(), 6, 0, 30);

Licensing

This library is licensed under the MIT license. If you're a potential user, or a current user, and this license causes an issue for you, I'm willing to consider multi-licensing it.