Authors: Michael DeCandia <[email protected]> and Stephen Becker <[email protected]>

License: BSD License

Copyright (c) 2007, Vonage Holdings

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HOTP – HMAC-Based One-Time Password Algorithm

* HOTP: Implements RFC 4226 using Ruby. (http://www.ietf.org/rfc/rfc4226.txt)  HOTP is an HMAC-SHA1 based algorithm

Download

The latest version of hotp can be found at

* http://rubyforge.org/hotp/

Installation

Normal Installation

Setup based installation is currently unsupported

GEM Installation

% gem install hotp

Usage, …

HOTP

The HOTP object can be used to calculate the HOTP value for any secret and count. The number of digits in the HOTP value is determined by an optional parameter. The default HOTP value is 6 digits long.

Creating an HOTP instance

h = HOTP.new() h.secret=“12345678901234567890” # 20 byte key h.count=0 # Where to start calculating h.digits=6 # How many digits to return (length of the HOTP value) puts(h.hotp) # => “755224” h.count=1 # Change the count puts(h.update) # => “287082”

Using HOTP as a class method

secret = “12345678901234567890” count = 0 puts(HOTP::hotp(secret,count)) # => “755224”