oath_totp_validate43
Api function
Usage
#include <oath.h>
int oath_totp_validate4(const char * secret, size_t secret_length, time_t now, unsigned time_step_size, time_t start_offset, size_t window, int * otp_pos, uint64_t * otp_counter, int flags, 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 |
int * otp_pos
|
output search position in search window (may be NULL). |
uint64_t * otp_counter
|
counter value used to calculate OTP value (may be NULL). |
int flags
|
flags indicating mode, one of |
const char * otp
|
the OTP to validate. |
Overview
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.
The flags parameter may be used to change the MAC function, for example OATH_TOTP_HMAC_SHA256 or OATH_TOTP_HMAC_SHA512.
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
2.6.0
Releases
4 releases since Debian 11 (Bullseye); the text changed 3 times.