NAME Pass::OTP - Perl implementation of HOTP / TOTP algorithms SYNOPSIS use Pass::OTP qw(otp); use Pass::OTP::URI qw(parse); my $uri = "otpauth://totp/ACME:john.doe@email.com?secret=HXDMVJECJJWSRB3HWIZR4IFUGFTMXBOZ&issuer=ACME&digits=6"; my $otp_code = otp(parse($uri)); DESCRIPTION The "Pass::OTP" module provides implementation of HOTP and TOTP algorithms according to the RFC 4226 and RFC 6238. FUNCTIONS hotp(%options) Computes HMAC-based One-time Password (RFC 4226). HOTP(K,C) = Truncate(HMAC-SHA-1(K,C)) Step 1: Generate an HMAC-SHA-1 value Let HS = HMAC-SHA-1(K,C) Step 2: Generate a 4-byte string (Dynamic Truncation) Let Sbits = DT(HS) Step 3: Compute an HOTP value Let Snum = StToNum(Sbits) # Convert S to a number in 0..2^{31}-1 Return D = Snum mod 10^Digit # D us a number in the range 0..10^{Digit}-1 totp(%options) Computes Time-based One-time Password (RFC 6238). TOTP = HOTP(K,T) T = (Current Unix time - T0) / X otp(%options) Convenience wrapper which calls totp/hotp according to options. SEE ALSO Digest::HMAC oathtool(1) RFC 4226 RFC 6238 COPYRIGHT AND LICENSE Copyright (C) 2020 Jan Baier This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License. See for more information.