- NAME
- SYNOPSIS
- DESCRIPTION
- RETURN VALUES
- CONFORMING TO
- SEE ALSO
- COPYRIGHT

# NAME

OTP_generate - One-Time Password Algorithm

# SYNOPSIS

     #include <openssl/otp.h>

     typedef struct OTP_PARAMS_st {
            int type;
            int te;
            void *option;
            size_t option_size;
            int otp_digits;
            /* adjust the clock in seconds */
            int offset;
     } OTP_PARAMS;

     int OTP_generate(const OTP_PARAMS *params,
                      const void *event, size_t eventlen,
                      unsigned int *otp,
                      const unsigned char *key, size_t keylen);

# DESCRIPTION

Applications should use the higher level functions EVP_DigestInit(3) etc. instead of calling the hash functions directly.

SM3 (ShangMi#3 Hash Algorithm) is a cryptographic hash function with a 256 bit output.

sm3() computes the SM3 message digest of the n bytes at d and places it in md (which must have space for SHA_DIGEST_LENGTH == 20 bytes of output). If md is NULL, the digest is placed in a static array. Note: setting md to NULL is not thread safe.

The following functions may be used if the message is not completely stored in memory:

sm3_nit() initializes a sm3_ctx_t structure.

sm3_update() can be called repeatedly with chunks of the message to be hashed (len bytes at data).

sm3_final() places the message digest in md, which must have space for SM3_DIGEST_LENGTH == 32 bytes of output, and erases the sm3_ctx_t.

# RETURN VALUES

sm3_init(), sm3_update(), sm3_final(), sm3_compress() and sm3() return void.

# CONFORMING TO

GM/T 0004-2012 SM3 Cryptogrpahic Hash Algorithm.

# SEE ALSO

EVP_DigestInit(3)

# COPYRIGHT

Copyright 2014-2019 The GmSSL Project. All Rights Reserved.

Licensed under the GmSSL license (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at http://gmssl.org/license.html.