StrongAuth (Two-Factor Authentication) iOS client.
Author: Dave MacLachlan <dmaclach@google.com
This client generates and displays one time passwords for logging in to
GAIA, or any other system which supports HOTP[1] or TOTP[2].
It is designed to be configured via a URL handler, as follows:
otpauth://TYPE/LABEL?PARAMETERS
where TYPE is "hotp" or "totp" and LABEL is a human readable label to help
distinguish multiple otp generators.
The supported PARAMETERS are:
algorithm=(SHA1|SHA256|SHA512|MD5)
OPTIONAL, defaults to SHA1.
secret=[websafe Base64 encoded secret key, no padding]
REQUIRED, 128 bits or more.
digits=(6|8)
OPTIONAL, defaults to 6.
counter=N (hotp specific)
REQUIRED
period=N (totp specific)
OPTIONAL, defaults to 30.
References:
1. HOTP: An HMAC-Based One-Time Password Algorithm
http://tools.ietf.org/html/rfc4226
2. TOTP: Time-based One-time Password Algorithm
http://tools.ietf.org/html/draft-mraihi-totp-timebased