.\" $OpenBSD: EVP_sm4_cbc.3,v 1.1 2019/03/18 05:56:24 schwarze Exp $
.\" full merge up to: OpenSSL 87103969 Oct 1 14:11:57 2018 -0700
.\"
.\" Copyright (c) 2017 Ribose Inc
.\" Copyright (c) 2019 Ingo Schwarze <schwarze@openbsd.org>
.\" The original version of this file
.\" was written by Ronald Tse <ronald.tse@ribose.com>.
.\"
.\" Permission to use, copy, modify, and/or distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
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.Dd $Mdocdate: March 18 2019 $
.Dt EVP_SM4_CBC 3
.Os
.Sh NAME
.Nm EVP_sm4_cbc ,
.Nm EVP_sm4_ecb ,
.Nm EVP_sm4_cfb ,
.Nm EVP_sm4_cfb128 ,
.Nm EVP_sm4_ofb ,
.Nm EVP_sm4_ctr
.Nd EVP SM4 cipher
.Sh SYNOPSIS
.In openssl/evp.h
.Ft const EVP_CIPHER *
.Fn EVP_sm4_cbc void
.Ft const EVP_CIPHER *
.Fn EVP_sm4_ecb void
.Ft const EVP_CIPHER *
.Fn EVP_sm4_cfb void
.Ft const EVP_CIPHER *
.Fn EVP_sm4_cfb128 void
.Ft const EVP_CIPHER *
.Fn EVP_sm4_ofb void
.Ft const EVP_CIPHER *
.Fn EVP_sm4_ctr void
.Sh DESCRIPTION
These functions provide the SM4 blockcipher in the
.Xr evp 3
framework.
.Pp
All modes use a key length of 128 bits and act on blocks of 128
bits.
.Pp
.Fn EVP_sm4_cfb
is an alias for
.Fn EVP_sm4_cfb128 .
.Pp
With an argument of
.Qq sm4
or
.Qq SM4 ,
.Xr EVP_get_cipherbyname 3
returns
.Fn EVP_sm4_cbc .
.Sh RETURN VALUES
These functions return an
.Vt EVP_CIPHER
structure that provides the implementation of the symmetric cipher.
.Sh SEE ALSO
.Xr evp 3 ,
.Xr EVP_EncryptInit 3
.Sh STANDARDS
.Rs
.%T Information security technology - SM4 block cipher algorithm
.%I National Standards of People's Republic of China
.%N GB/T 32907-2016
.%D August 29, 2016
.Re
.Sh HISTORY
These functions appeared in OpenSSL 1.1.1 and have been available since
.Ox 6.5 .