NAME¶

oath_totp_validate - API function

SYNOPSIS¶

#include <oath.h>

int oath_totp_validate(const char * secret, size_t secret_length, time_t now, unsigned time_step_size, time_t start_offset, size_t window, const char * otp);

ARGUMENTS¶

const char * secret

the shared secret string

size_t secret_length

length of secret

time_t now

Unix time value to validate TOTP for

unsigned time_step_size

time step system parameter (typically 30)

time_t start_offset

Unix time of when to start counting time steps (typically 0)

size_t window

how many OTPs after/before start OTP to test

const char * otp

the OTP to validate.

DESCRIPTION¶

Validate an OTP according to OATH TOTP algorithm per RFC 6238.

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

SINCE¶

1.6.0

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.