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More documentation.

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This commit is contained in:
Kyle
2014-04-24 20:37:00 -06:00
parent 459e9f880f
commit 84250b0501
6 changed files with 41 additions and 10 deletions
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21
totp.go
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@@ -13,11 +13,13 @@ import (
"time"
)
// TOTP represents an RFC 6238 Time-based One-Time Password instance.
type TOTP struct {
*OATH
step uint64
}
// Type returns OATH_TOTP.
func (otp *TOTP) Type() Type {
return OATH_TOTP
}
@@ -26,14 +28,17 @@ func (otp *TOTP) otp(counter uint64) string {
return otp.OATH.OTP(counter)
}
// OTP returns the OTP for the current timestep.
func (otp *TOTP) OTP() string {
return otp.otp(otp.OTPCounter())
}
// URL returns a TOTP URL (i.e. for putting in a QR code).
func (otp *TOTP) URL(label string) string {
return otp.OATH.URL(otp.Type(), label)
}
// SetProvider sets up the provider component of the OTP URL.
func (otp *TOTP) SetProvider(provider string) {
otp.provider = provider
}
@@ -42,10 +47,14 @@ func (otp *TOTP) otpCounter(t uint64) uint64 {
return (t - otp.counter) / otp.step
}
// OTPCounter returns the current time value for the OTP.
func (otp *TOTP) OTPCounter() uint64 {
return otp.otpCounter(uint64(time.Now().Unix()))
}
// NewOTP takes a new key, a starting time, a step, the number of
// digits of output (typically 6 or 8) and the hash algorithm to
// use, and builds a new OTP.
func NewTOTP(key []byte, start uint64, step uint64, digits int, algo crypto.Hash) *TOTP {
h := hashFromAlgo(algo)
if h == nil {
@@ -65,18 +74,11 @@ func NewTOTP(key []byte, start uint64, step uint64, digits int, algo crypto.Hash
}
// NewTOTPSHA1 will build a new TOTP using SHA-1.
func NewTOTPSHA1(key []byte, start uint64, step uint64, digits int) *TOTP {
return NewTOTP(key, start, step, digits, crypto.SHA1)
}
func NewTOTPSHA256(key []byte, start uint64, step uint64, digits int) *TOTP {
return NewTOTP(key, start, step, digits, crypto.SHA256)
}
func NewTOTPSHA512(key []byte, start uint64, step uint64, digits int) *TOTP {
return NewTOTP(key, start, step, digits, crypto.SHA512)
}
func hashFromAlgo(algo crypto.Hash) func() hash.Hash {
switch algo {
case crypto.SHA1:
@@ -99,6 +101,8 @@ func GenerateGoogleTOTP() *TOTP {
return NewTOTP(key, 0, 30, 6, crypto.SHA1)
}
// NewGoogleTOTP takes a secret as a base32-encoded string and
// returns an appropriate Google Authenticator TOTP instance.
func NewGoogleTOTP(secret string) (*TOTP, error) {
key, err := base32.StdEncoding.DecodeString(secret)
if err != nil {
@@ -154,6 +158,7 @@ func totpFromURL(u *url.URL) (*TOTP, string, error) {
return otp, label, nil
}
// QR generates a new TOTP QR code.
func (otp *TOTP) QR(label string) ([]byte, error) {
return otp.OATH.QR(otp.Type(), label)
}