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=head1 NAME

EVP_CIPHER_CTX_get_cipher_data, EVP_CIPHER_CTX_set_cipher_data - Routines to
inspect and modify EVP_CIPHER_CTX objects

=head1 SYNOPSIS

 #include <openssl/evp.h>

 void *EVP_CIPHER_CTX_get_cipher_data(const EVP_CIPHER_CTX *ctx);
 void *EVP_CIPHER_CTX_set_cipher_data(EVP_CIPHER_CTX *ctx, void *cipher_data);

=head1 DESCRIPTION

The EVP_CIPHER_CTX_get_cipher_data() function returns a pointer to the cipher
data relevant to EVP_CIPHER_CTX. The contents of this data is specific to the
particular implementation of the cipher. For example this data can be used by
engines to store engine specific information. The data is automatically
allocated and freed by OpenSSL, so applications and engines should not normally
free this directly (but see below).

The EVP_CIPHER_CTX_set_cipher_data() function allows an application or engine to
replace the cipher data with new data. A pointer to any existing cipher data is
returned from this function. If the old data is no longer required then it
should be freed through a call to OPENSSL_free().

=head1 RETURN VALUES

The EVP_CIPHER_CTX_get_cipher_data() function returns a pointer to the current
cipher data for the EVP_CIPHER_CTX.

The EVP_CIPHER_CTX_set_cipher_data() function returns a pointer to the old
cipher data for the EVP_CIPHER_CTX.

=head1 HISTORY

The EVP_CIPHER_CTX_get_cipher_data() and EVP_CIPHER_CTX_set_cipher_data()
functions were added in OpenSSL 1.1.0.

=head1 COPYRIGHT

Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (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
L<https://www.openssl.org/source/license.html>.

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