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

# NAME

EVP_chacha20, EVP_chacha20_poly1305 - EVP ChaCha20 stream cipher

# SYNOPSIS

     #include <openssl/evp.h>

     const EVP_CIPHER *EVP_chacha20(void)
     const EVP_CIPHER *EVP_chacha20_poly1305(void)

# DESCRIPTION

The ChaCha20 stream cipher for EVP.

EVP_chacha20()

  The ChaCha20 stream cipher. The key length is 256 bits, the IV is 128 bits long. The first 32 bits consists of a counter in little-endian order followed by a 96 bit nonce. For example a nonce of:

  000000000000000000000002

  With an initial counter of 42 (2a in hex) would be expressed as:

  2a000000000000000000000000000002

EVP_chacha20_poly1305()

  Authenticated encryption with ChaCha20-Poly1305. Like EVP_chacha20(), the key is 256 bits and the IV is 96 bits. This supports additional authenticated data (AAD) and produces a 128-bit authentication tag. See the "AEAD Interface" in EVP_EncryptInit(3) section for more information.

# RETURN VALUES

These functions return an EVP_CIPHER structure that contains the implementation of the symmetric cipher. See EVP_CIPHER_meth_new(3) for details of the EVP_CIPHER structure.

# SEE ALSO

evp(7), EVP_EncryptInit(3), EVP_CIPHER_meth_new(3)

# COPYRIGHT

Copyright 2017-2019 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL 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 https://www.openssl.org/source/license.html.