=pod

=head1 NAME

EVP_aes_128_cbc,
EVP_aes_192_cbc,
EVP_aes_256_cbc,
EVP_aes_128_cfb,
EVP_aes_192_cfb,
EVP_aes_256_cfb,
EVP_aes_128_cfb1,
EVP_aes_192_cfb1,
EVP_aes_256_cfb1,
EVP_aes_128_cfb8,
EVP_aes_192_cfb8,
EVP_aes_256_cfb8,
EVP_aes_128_cfb128,
EVP_aes_192_cfb128,
EVP_aes_256_cfb128,
EVP_aes_128_ctr,
EVP_aes_192_ctr,
EVP_aes_256_ctr,
EVP_aes_128_ecb,
EVP_aes_192_ecb,
EVP_aes_256_ecb,
EVP_aes_128_ofb,
EVP_aes_192_ofb,
EVP_aes_256_ofb,
EVP_aes_128_cbc_hmac_sha1,
EVP_aes_256_cbc_hmac_sha1,
EVP_aes_128_cbc_hmac_sha256,
EVP_aes_256_cbc_hmac_sha256,
EVP_aes_128_ccm,
EVP_aes_192_ccm,
EVP_aes_256_ccm,
EVP_aes_128_gcm,
EVP_aes_192_gcm,
EVP_aes_256_gcm,
EVP_aes_128_ocb,
EVP_aes_192_ocb,
EVP_aes_256_ocb,
EVP_aes_128_wrap,
EVP_aes_192_wrap,
EVP_aes_256_wrap,
EVP_aes_128_wrap_pad,
EVP_aes_192_wrap_pad,
EVP_aes_256_wrap_pad,
EVP_aes_128_xts,
EVP_aes_256_xts
- EVP AES cipher

=head1 SYNOPSIS

=for openssl generic

 #include <openssl/evp.h>

 const EVP_CIPHER *EVP_ciphername(void)

I<EVP_ciphername> is used a placeholder for any of the described cipher
functions, such as I<EVP_aes_128_cbc>.

=head1 DESCRIPTION

The AES encryption algorithm for EVP.

=over 4

=item EVP_aes_128_cbc(),
EVP_aes_192_cbc(),
EVP_aes_256_cbc(),
EVP_aes_128_cfb(),
EVP_aes_192_cfb(),
EVP_aes_256_cfb(),
EVP_aes_128_cfb1(),
EVP_aes_192_cfb1(),
EVP_aes_256_cfb1(),
EVP_aes_128_cfb8(),
EVP_aes_192_cfb8(),
EVP_aes_256_cfb8(),
EVP_aes_128_cfb128(),
EVP_aes_192_cfb128(),
EVP_aes_256_cfb128(),
EVP_aes_128_ctr(),
EVP_aes_192_ctr(),
EVP_aes_256_ctr(),
EVP_aes_128_ecb(),
EVP_aes_192_ecb(),
EVP_aes_256_ecb(),
EVP_aes_128_ofb(),
EVP_aes_192_ofb(),
EVP_aes_256_ofb()

AES for 128, 192 and 256 bit keys in the following modes: CBC, CFB with 128-bit
shift, CFB with 1-bit shift, CFB with 8-bit shift, CTR, ECB, and OFB.

=item EVP_aes_128_cbc_hmac_sha1(),
EVP_aes_256_cbc_hmac_sha1()

Authenticated encryption with AES in CBC mode using SHA-1 as HMAC, with keys of
128 and 256 bits length respectively. The authentication tag is 160 bits long.

WARNING: this is not intended for usage outside of TLS and requires calling of
some undocumented ctrl functions. These ciphers do not conform to the EVP AEAD
interface.

=item EVP_aes_128_cbc_hmac_sha256(),
EVP_aes_256_cbc_hmac_sha256()

Authenticated encryption with AES in CBC mode using SHA256 (SHA-2, 256-bits) as
HMAC, with keys of 128 and 256 bits length respectively. The authentication tag
is 256 bits long.

WARNING: this is not intended for usage outside of TLS and requires calling of
some undocumented ctrl functions. These ciphers do not conform to the EVP AEAD
interface.

=item EVP_aes_128_ccm(),
EVP_aes_192_ccm(),
EVP_aes_256_ccm(),
EVP_aes_128_gcm(),
EVP_aes_192_gcm(),
EVP_aes_256_gcm(),
EVP_aes_128_ocb(),
EVP_aes_192_ocb(),
EVP_aes_256_ocb()

AES for 128, 192 and 256 bit keys in CBC-MAC Mode (CCM), Galois Counter Mode
(GCM) and OCB Mode respectively. These ciphers require additional control
operations to function correctly, see the L<EVP_EncryptInit(3)/AEAD INTERFACE>
section for details.

=item EVP_aes_128_wrap(),
EVP_aes_192_wrap(),
EVP_aes_256_wrap(),
EVP_aes_128_wrap_pad(),
EVP_aes_192_wrap_pad(),
EVP_aes_256_wrap_pad()

AES key wrap with 128, 192 and 256 bit keys, as according to RFC 3394 section
2.2.1 ("wrap") and RFC 5649 section 4.1 ("wrap with padding") respectively.

=item EVP_aes_128_xts(),
EVP_aes_256_xts()

AES XTS mode (XTS-AES) is standardized in IEEE Std. 1619-2007 and described in NIST
SP 800-38E. The XTS (XEX-based tweaked-codebook mode with ciphertext stealing)
mode was designed by Prof. Phillip Rogaway of University of California, Davis,
intended for encrypting data on a storage device.

XTS-AES provides confidentiality but not authentication of data. It also
requires a key of double-length for protection of a certain key size.
In particular, XTS-AES-128 (B<EVP_aes_128_xts>) takes input of a 256-bit key to
achieve AES 128-bit security, and XTS-AES-256 (B<EVP_aes_256_xts>) takes input
of a 512-bit key to achieve AES 256-bit security.

The XTS implementation in OpenSSL does not support streaming. That is there must
only be one L<EVP_EncryptUpdate(3)> call per L<EVP_EncryptInit_ex(3)> call (and
similarly with the "Decrypt" functions).

The I<iv> parameter to L<EVP_EncryptInit_ex(3)> or L<EVP_DecryptInit_ex(3)> is
the XTS "tweak" value.

=back

=head1 NOTES

Developers should be aware of the negative performance implications of
calling these functions multiple times and should consider using
L<EVP_CIPHER_fetch(3)> with L<EVP_CIPHER-AES(7)> instead.
See L<crypto(7)/Performance> for further information.

=head1 RETURN VALUES

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

=head1 SEE ALSO

L<evp(7)>,
L<EVP_EncryptInit(3)>,
L<EVP_CIPHER_meth_new(3)>

=head1 COPYRIGHT

Copyright 2017-2025 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>.

=cut

