mirror of https://gitlab.com/octospacc/SmolOTP.git
35 lines
902 B
C
35 lines
902 B
C
/*
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*
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* TOTP: Time-Based One-Time Password Algorithm
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* Copyright (c) 2017, fmount <fmount9@autistici.org>
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*
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* This software is distributed under MIT License
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*
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* Compute the hmac using openssl library.
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* SHA-1 engine is used by default, but you can pass another one,
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*
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* e.g EVP_md5(), EVP_sha224, EVP_sha512, etc
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*
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*/
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#include "rfc6238.h"
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time_t getUnixTime(int timezoneOffset)
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{
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// note: subtract, not add, the TZ offset from the system time to get the UTC time based on TZ
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// eg. if localTime = 12:00, then utcTime = localTime - (+02) = 10:00
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return (time(NULL) - (timezoneOffset * 60 * 60));
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}
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time_t getTotpTime(time_t t0, int timestep, int timezoneOffset)
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{
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return (floor((getUnixTime(timezoneOffset) - t0) / timestep));
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}
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uint32_t TOTP(uint8_t *key, size_t kl, uint64_t time, int digits)
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{
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uint32_t totp;
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totp = HOTP(key, kl, time, digits);
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return totp;
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}
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