oath_hotp_generate man page
oath_hotp_generate — API function
int oath_hotp_generate(const char * secret, size_t secret_length, uint64_t moving_factor, unsigned digits, bool add_checksum, size_t truncation_offset, char * output_otp);
- const char * secret
the shared secret string
- size_t secret_length
length of secret
- uint64_t moving_factor
a counter indicating the current OTP to generate
- unsigned digits
number of requested digits in the OTP, excluding checksum
- bool add_checksum
whether to add a checksum digit or not
- size_t truncation_offset
use a specific truncation offset
- char * output_otp
output buffer, must have room for the output OTP plus zero
Generate a one-time-password using the HOTP algorithm as described in RFC 4226.
Use a value of OATH_HOTP_DYNAMIC_TRUNCATION for truncation_offset unless you really need a specific truncation offset.
To find out the size of the OTP you may use the OATH_HOTP_LENGTH() macro. The output_otp buffer must be have room for that length plus one for the terminating NUL.
Currently only values 6, 7 and 8 for digits are supported, and the add_checksum value is ignored. These restrictions may be lifted in future versions, although some limitations are inherent in the protocol.
On success, OATH_OK (zero) is returned, otherwise an error code is returned.
Report bugs to <email@example.com>. liboath home page: http://www.gnu.org/software/liboath/ General help using GNU software: http://www.gnu.org/gethelp/
Copyright © 2009-2015 Simon Josefsson.
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