EVP_CIPHER-NULL(7)

EVP_CIPHER-NULL(7) | OpenSSL | EVP_CIPHER-NULL(7)

# 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>.

2026-06-09 | 3.5.7