.\" DO NOT MODIFY THIS FILE!  It was generated by gdoc.
.TH "oath_hotp_validate" 3 "2.6.11" "liboath" "liboath"
.SH NAME
oath_hotp_validate \- API function
.SH SYNOPSIS
.B #include <oath.h>
.sp
.BI "int oath_hotp_validate(const char * " secret ", size_t " secret_length ", uint64_t " start_moving_factor ", size_t " window ", const char * " otp ");"
.SH ARGUMENTS
.IP "const char * secret" 12
the shared secret string
.IP "size_t secret_length" 12
length of \fIsecret\fP
.IP "uint64_t start_moving_factor" 12
start counter in OTP stream
.IP "size_t window" 12
how many OTPs after start counter to test
.IP "const char * otp" 12
the OTP to validate.
.SH "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.
.SH "RETURNS"
Returns position in OTP window (zero is first position),
or \fBOATH_INVALID_OTP\fP if no OTP was found in OTP window, or an
error code.
.SH "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/
.SH COPYRIGHT
Copyright \(co 2009-2020 Simon Josefsson.
.br
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.