totp_rfc6238

A rust crate for generating TOTP codes (tokens) defined in RFC 6238.

Features of this crate

Both low-level and high-level APIs are provided.
The length of the codes, the initial counter time (T0), update time interval (period) and hash algorithm are configurable.
HMAC algorithms are implemented by ring.
Read or write "Key Uri Format" (URIs start with otpauth://totp/) (the oathuri feature gate).
Read or write key from base32-encoded string (the oathuri feature gate).

Note

This implementation does NOT consider the time earlier than the Unix epoch (1970-01-01T00:00:00Z).

Example

use totp_rfc6238::{HashAlgorithm, TotpGenerator};
fn main() {
    let key = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890+/";
    // Create a non-standard TOTP code generator: 8-digit, updating every 60
    // seconds, starting at "Jan 01 1970 00:16:40 UTC", using HMAC-SHA512.
    let mut totp_generator = TotpGenerator::new()
        .set_digit(8).unwrap()
        .set_step(60).unwrap()
        .set_t0(1000)
        .set_hash_algorithm(HashAlgorithm::SHA512)
        .build();
    
    let output1 = totp_generator.get_code(key);
    println!("Your TOTP code for current time is: {}", output1);
    
    let output2 = totp_generator.get_next_update_time().unwrap();
    println!("Next update will be at the unix timestamp of {}", output2);
    
    let output3 = totp_generator.get_code_window(key, -5..=5).unwrap();
    println!("Codes for 5 minutes earlier or later are:");
    for i in output3 {
        println!("  {}", i);
    }
}

Changelog

See here.

Incompatible API breaking changes

v0.3.1 -> v0.4.0
v0.2.0 -> v0.3.0

Warning

The codes of this crate has not been audited.

Features that may be related to but NOT implemented in this crate

Read or write QR codes.

Contribution

Any contribution intentionally submitted for inclusion in openssl-src by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
Pull requests are always welcome.

License

This tool is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.
See LICENSE-APACHE, LICENSE-MIT for details.

totp_rfc6238 0.4.2