- NAME
- DESCRIPTION

- Algorithm Names
- Parameters

- NOTES
- SEE ALSO
- HISTORY
- COPYRIGHT

# NAME

EVP_CIPHER-AES - The AES EVP_CIPHER implementations

# DESCRIPTION

Support for AES symmetric encryption using the EVP_CIPHER API.

## Algorithm Names

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

"AES-128-CBC", "AES-192-CBC" and "AES-256-CBC"
"AES-128-CBC-CTS", "AES-192-CBC-CTS" and "AES-256-CBC-CTS"
"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"
"AES-128-CTR", "AES-192-CTR" and "AES-256-CTR"
"AES-128-ECB", "AES-192-ECB" and "AES-256-ECB"
"AES-192-OFB", "AES-128-OFB" and "AES-256-OFB"
"AES-128-XTS" and "AES-256-XTS"
"AES-128-CCM", "AES-192-CCM" and "AES-256-CCM"
"AES-128-GCM", "AES-192-GCM" and "AES-256-GCM"
"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"
"AES-128-CBC-HMAC-SHA1", "AES-256-CBC-HMAC-SHA1", "AES-128-CBC-HMAC-SHA256" and "AES-256-CBC-HMAC-SHA256"

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

"AES-128-OCB", "AES-192-OCB" and "AES-256-OCB"
"AES-128-SIV", "AES-192-SIV" and "AES-256-SIV"
"AES-128-GCM-SIV", "AES-192-GCM-SIV" and "AES-256-GCM-SIV"

## Parameters

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

# NOTES

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

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

The AES-XTS implementations allow streaming to be performed, but each EVP_EncryptUpdate(3) or 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.

# SEE ALSO

provider-cipher(7), OSSL_PROVIDER-FIPS(7), OSSL_PROVIDER-default(7)

# HISTORY

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

# 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 https://www.openssl.org/source/license.html.