CookieParser return a one-time password parser, where otp extracted form HTTP Cookie.

JSONBodyParser return a one-time password parser, where otp extracted form request body.

QueryParser return a one-time password parser, where otp extracted form HTTP query string.

XHeaderParser return a one-time password parser, where otp extracted form "X-" header.

ErrInvalidOTP is returned by twofactor strategy, When the user-supplied an invalid one time password and verification process failed.

ErrMissingOTP is returned by Parser, When one-time password missing or empty in HTTP request.

TwoFactor represents two factor authentication strategy.

Manager load and store user OTP Verifier.

Parser parse and extract one-time password from incoming HTTP request.

Verifier represents one-time password verification.