1oath_hotp_generate(3)               liboath              oath_hotp_generate(3)
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NAME

6       oath_hotp_generate - API function
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SYNOPSIS

9       #include <oath.h>
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11       int  oath_hotp_generate(const  char  *  secret,  size_t  secret_length,
12       uint64_t moving_factor,  unsigned  digits,  bool  add_checksum,  size_t
13       truncation_offset, char * output_otp);
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ARGUMENTS

16       const char * secret
17                   the shared secret string
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19       size_t secret_length
20                   length of secret
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22       uint64_t moving_factor
23                   a counter indicating the current OTP to generate
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25       unsigned digits
26                   number of requested digits in the OTP, excluding checksum
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28       bool add_checksum
29                   whether to add a checksum digit or not
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31       size_t truncation_offset
32                   use a specific truncation offset
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34       char * output_otp
35                   output buffer, must have room for the output OTP plus zero
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DESCRIPTION

38       Generate  a  one-time-password using the HOTP algorithm as described in
39       RFC 4226.
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41       Use  a  value  of  OATH_HOTP_DYNAMIC_TRUNCATION  for  truncation_offset
42       unless you really need a specific truncation offset.
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44       To  find  out  the  size  of the OTP you may use the OATH_HOTP_LENGTH()
45       macro.  The output_otp buffer must be have room for  that  length  plus
46       one for the terminating NUL.
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48       Currently  only  values  6,  7  and 8 for digits are supported, and the
49       add_checksum value is ignored.  These restrictions  may  be  lifted  in
50       future  versions,  although some limitations are inherent in the proto‐
51       col.
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RETURNS

54       On success, OATH_OK (zero) is returned,  otherwise  an  error  code  is
55       returned.
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REPORTING BUGS

58       Report  bugs  to  <oath-toolkit-help@nongnu.org>.   liboath  home page:
59       http://www.gnu.org/software/liboath/ General help using  GNU  software:
60       http://www.gnu.org/gethelp/
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63       Copyright © 2009-2020 Simon Josefsson.
64       Copying  and  distribution  of this file, with or without modification,
65       are permitted in any medium  without  royalty  provided  the  copyright
66       notice and this notice are preserved.
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70liboath                              2.6.6               oath_hotp_generate(3)
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