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

# NAME

FFX_CTX_new, FFX_CTX_free, FFX_init, FFX_encrypt, FFX_decrypt, FFX_compute_luhn - Format-Preserving Encryption

# SYNOPSIS

     #include <openssl/ffx.h>

     FFX_CTX *FFX_CTX_new(void);
     void FFX_CTX_free(FFX_CTX *ctx);

     int FFX_init(FFX_CTX *ctx, const EVP_CIPHER *cipher,
                  const unsigned char *key, int flag);
     int FFX_encrypt(FFX_CTX *ctx, const char *in, char *out, size_t iolen,
                     unsigned char *tweak, size_t tweaklen);
     int FFX_decrypt(FFX_CTX *ctx, const char *in, char *out, size_t iolen,
                     unsigned char *tweak, size_t tweaklen);

     int  FFX_compute_luhn(const char *in, size_t inlen);

# 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.