=pod

=head1 NAME

EVP_CIPHER-AES - The AES EVP_CIPHER implementations

=head1 DESCRIPTION

Support for AES symmetric encryption using the B<EVP_CIPHER> API.

=head2 Algorithm Names

The following algorithms are available in the FIPS provider as well as the
default provider:

=over 4

=item "AES-128-CBC", "AES-192-CBC" and  "AES-256-CBC"

=item "AES-128-CBC-CTS", "AES-192-CBC-CTS" and "AES-256-CBC-CTS"

=item "AES-128-CFB", "AES-192-CFB", "AES-256-CFB",
"AES-128-CFB1", "AES-192-CFB1", "AES-256-CFB1",
"AES-128-CFB8", "AES-192-CFB8" and "AES-256-CFB8"

=item "AES-128-CTR", "AES-192-CTR" and "AES-256-CTR"

=item "AES-128-ECB", "AES-192-ECB" and "AES-256-ECB"

=item "AES-192-OFB", "AES-128-OFB" and "AES-256-OFB"

=item "AES-128-XTS" and "AES-256-XTS"

=item "AES-128-CCM", "AES-192-CCM" and "AES-256-CCM"

=item "AES-128-GCM", "AES-192-GCM" and "AES-256-GCM"

=item "AES-128-WRAP", "AES-192-WRAP", "AES-256-WRAP",
"AES-128-WRAP-PAD", "AES-192-WRAP-PAD", "AES-256-WRAP-PAD",
"AES-128-WRAP-INV", "AES-192-WRAP-INV", "AES-256-WRAP-INV",
"AES-128-WRAP-PAD-INV", "AES-192-WRAP-PAD-INV" and "AES-256-WRAP-PAD-INV"

=item "AES-128-CBC-HMAC-SHA1", "AES-256-CBC-HMAC-SHA1",
"AES-128-CBC-HMAC-SHA256" and "AES-256-CBC-HMAC-SHA256"

=back

The following algorithms are available in the default provider, but not the
FIPS provider:

=over 4

=item "AES-128-OCB", "AES-192-OCB" and "AES-256-OCB"

=item "AES-128-SIV", "AES-192-SIV" and "AES-256-SIV"

=item "AES-128-GCM-SIV", "AES-192-GCM-SIV" and "AES-256-GCM-SIV"

=back

=head2 Parameters

This implementation supports the parameters described in
L<EVP_EncryptInit(3)/PARAMETERS>.

=head1 NOTES

The AES-SIV and AES-WRAP mode implementations do not support streaming. That
means to obtain correct results there can be only one L<EVP_EncryptUpdate(3)>
or L<EVP_DecryptUpdate(3)> call after the initialization of the context.

When wrapping with AES-WRAP-PAD ciphers, the output buffer must be at least
I<inl> rounded up to the cipher block size (8 bytes) plus the block size.
That is, the minimum output buffer size is C<((inl + 7) / 8) * 8 + 8> bytes.

The AES-XTS implementations allow streaming to be performed, but each
L<EVP_EncryptUpdate(3)> or L<EVP_DecryptUpdate(3)> call requires each input
to be a multiple of the blocksize. Only the final EVP_EncryptUpdate() or
EVP_DecryptUpdate() call can optionally have an input that is not a multiple
of the blocksize but is larger than one block. In that case ciphertext
stealing (CTS) is used to fill the block.

=head1 SEE ALSO

L<provider-cipher(7)>, L<OSSL_PROVIDER-FIPS(7)>, L<OSSL_PROVIDER-default(7)>

=head1 HISTORY

The GCM-SIV mode ciphers were added in OpenSSL version 3.2.

=head1 COPYRIGHT

Copyright 2021-2026 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
