man > EVP_CIPHER-NULL(7ssl)

EVP_CIPHER-NULL(7SSL)                          OpenSSL                         EVP_CIPHER-NULL(7SSL)

NAME
       EVP_CIPHER-NULL - The NULL EVP_CIPHER implementation

DESCRIPTION
       Support for a NULL symmetric encryption using the EVP_CIPHER API.  This is used when the TLS
       cipher suite is TLS_NULL_WITH_NULL_NULL.  This does no encryption (just copies the data) and
       has a mac size of zero.

   Algorithm Name
       The following algorithm is available in the default provider:

       "NULL"

   Parameters
       This implementation supports the following parameters:

       Gettable EVP_CIPHER parameters

       See "Gettable EVP_CIPHER parameters" in EVP_EncryptInit(3)

       Gettable EVP_CIPHER_CTX parameters

       "keylen" (OSSL_CIPHER_PARAM_KEYLEN) <unsigned integer>
       "ivlen" (OSSL_CIPHER_PARAM_IVLEN and <OSSL_CIPHER_PARAM_AEAD_IVLEN) <unsigned integer>
       "tls-mac" (OSSL_CIPHER_PARAM_TLS_MAC) <octet ptr>

       See "PARAMETERS" in EVP_EncryptInit(3) for further information.

       Settable EVP_CIPHER_CTX parameters

       "tls-mac-size" (OSSL_CIPHER_PARAM_TLS_MAC_SIZE) <unsigned integer>

       See "PARAMETERS" in EVP_EncryptInit(3) for further information.

CONFORMING TO
       RFC 5246 section-6.2.3.1

SEE ALSO
       provider-cipher(7), OSSL_PROVIDER-default(7)

COPYRIGHT
       Copyright 2023 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 <https://www.openssl.org/source/license.html>.

3.0.13                                       2026-07-29                        EVP_CIPHER-NULL(7SSL)