README
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gotp
A simple library to assist with the generation of time-based and HMAC-based one-time passcodes for two-factor authentication.
Documentation
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Overview ¶
Package gotp is a Go library implementing the RFC6238 time-based one-time password algorithm, and RFC4226 HMAC-based one-time password algorithm. RFC6238 is based off RFC4226, however it uses a counter step of increments of 30 seconds since 1970-01-01T00:00:00Z.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( // The step to use. RFC6238 dictates a step of 30 seconds, however some // implementations use alternative steps. StepSeconds = 30 // SeedLength is the length of the HMAC secret, or seed. // Usually 10 or so. SeedLength int = 20 // TokenLength is the length of the generated TOTP. // Usually 6, sometimes 8. TokenLength = 6 )
Functions ¶
This section is empty.
Types ¶
type Token ¶
Token is the core one-time password struct. It is naive, and does not store information about its counter step to facilitate simple construction of time-based one-time password.
func TokenFromBytes ¶
TokenFromBytes generates a new OTP from an existing seed.
func (*Token) GenerateOTP ¶
GenerateOTP generates a single six-digit OTP based on the OTP's seed and the counter factor.
func (*Token) GenerateTOTP ¶
GenerateTOTP generates an OTP value based on the `genTime` provided time.
func (*Token) VerifyChallenge ¶
VerifyChallenge verifies the `challenge` password. If `drift` is true, it will verify the challenge against a 90-second window of TOTP generation to protect against clock drift denial of service, through no fault of the user.
Source Files