NAME

       oath_hotp_validate - API function

SYNOPSIS

       #include <oath.h>

       int    oath_hotp_validate(const    char   *   secret,   size_t   secret_length,   uint64_t
       start_moving_factor, size_t window, const char * otp);

ARGUMENTS

       const char * secret
                   the shared secret string

       size_t secret_length
                   length of secret

       uint64_t start_moving_factor
                   start counter in OTP stream

       size_t window
                   how many OTPs after start counter to test

       const char * otp
                   the OTP to validate.

DESCRIPTION

       Validate an OTP according to OATH HOTP algorithm per RFC 4226.

       Currently only OTP lengths of 6, 7 or 8 digits are supported.  This  restrictions  may  be
       lifted in future versions, although some limitations are inherent in the protocol.

RETURNS

       Returns position in OTP window (zero is first position), or OATH_INVALID_OTP if no OTP was
       found in OTP window, or an error code.

REPORTING BUGS

       Report     bugs     to     <oath-toolkit-help@nongnu.org>.      liboath     home     page:
       https://www.nongnu.org/oath-toolkit/      General     help     using     GNU     software:
       http://www.gnu.org/gethelp/

COPYRIGHT

       Copyright © 2009-2020 Simon Josefsson.
       Copying and distribution of this file, with or without modification, are permitted in  any
       medium without royalty provided the copyright notice and this notice are preserved.