README
¶
OTP
Package go-otp implements one-time-password generators used in 2-factor authentication systems like RSA-tokens and Google Authenticator. Currently this supports both HOTP (RFC-4226) and TOTP (RFC-6238).
Install
$ go get github.com/hgfischer/go-otp
Usage
Check API docs, with examples, at http://godoc.org/github.com/hgfischer/go-otp
License
Copyright (c) 2014, Herbert G. Fischer All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the organization nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL HERBERT G. FISCHER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Documentation
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Overview ¶
Package otp implements one-time-password generators used in 2-factor authentication systems like RSA-tokens and Google Authenticator. Currently this supports both HOTP (RFC-4226) and TOTP (RFC-6238).
All tests used in this package, uses reference values from both RFCs to ensure compatibility with another OTP implementations.
Index ¶
Constants ¶
const ( DefaultLength = 6 // Default length of the generated tokens DefaultPeriod = 30 // Default time period for TOTP tokens, in seconds DefaultRandomSecretLength = 100 // Default random secret length DefaultWindowBack = 1 // Default TOTP verification window back steps DefaultWindowForward = 1 // Default TOTP verification window forward steps )
Default settings for all generators
const (
MaxLength = 10 // Maximum token length
)
Maximum values for all generators
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type HOTP ¶
type HOTP struct {
Secret string // The secret used to generate the token
Length uint8 // The token size, with a maximum determined by MaxLength
Counter uint64 // The counter used as moving factor
IsBase32Secret bool // If true, the secret will be used as a Base32 encoded string
}
HOTP is used to generate tokens based on RFC-4226.
Example:
hotp := &HOTP{Secret: "your-secret", Counter: 1000, Length: 8, IsBase32Secret: true}
token := hotp.Get()
HOTP assumes a set of default values for Secret, Length, Counter, and IsBase32Secret. If no Secret is informed, HOTP will generate a random one that you need to store with the Counter, for future token verifications. Check this package constants to see the current default values.
type TOTP ¶
type TOTP struct {
Secret string // The secret used to generate a token
Length uint8 // The token length
Time time.Time // The time used to generate the token
IsBase32Secret bool //
Period uint8 // The step size to slice time, in seconds
WindowBack uint8 // How many steps HOTP will go backwards to validate a token
WindowForward uint8 // How many steps HOTP will go forward to validate a token
}
TOTP is used to generate tokens based on RFC-6238.
Example:
totp := &TOTP{Secret: "your-secret", IsBase32Secret: true}
token := totp.Get()
TOTP assumes a set of default values for Secret, Length, Time, Period, WindowBack, WindowForward and IsBase32Secret ¶
If no Secret is informed, TOTP will generate a random one that you need to store with the Counter, for future token verifications.
Check this package constants to see the current default values.
Source Files
Directories