=head1 DESCRIPTION
-The EVP cipher routines are a high level interface to certain
+The EVP cipher routines are a high-level interface to certain
symmetric ciphers.
EVP_CIPHER_CTX_new() creates a cipher context.
EVP_EncryptUpdate() encrypts B<inl> bytes from the buffer B<in> and
writes the encrypted version to B<out>. This function can be called
multiple times to encrypt successive blocks of data. The amount
-of data written depends on the block alignment of the encrypted data:
-as a result the amount of data written may be anything from zero bytes
-to (inl + cipher_block_size - 1) so B<out> should contain sufficient
-room. The actual number of bytes written is placed in B<outl>. It also
+of data written depends on the block alignment of the encrypted data.
+For most ciphers and modes, the amount of data written can be anything
+from zero bytes to (inl + cipher_block_size - 1) bytes.
+For wrap cipher modes, the amount of data written can be anything
+from zero bytes to (inl + cipher_block_size) bytes.
+For stream ciphers, the amount of data written can be anything from zero
+bytes to inl bytes.
+Thus, B<out> should contain sufficient room for the operation being performed.
+The actual number of bytes written is placed in B<outl>. It also
checks if B<in> and B<out> are partially overlapping, and if they are
0 is returned to indicate failure.
=item EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
-Sets the CCM nonce (IV) length. This call can only be made before specifying an
-nonce value. The nonce length is given by B<15 - L> so it is 7 by default for
+Sets the CCM nonce (IV) length. This call can only be made before specifying
+a nonce value. The nonce length is given by B<15 - L> so it is 7 by default for
AES.
=back
=head1 NOTES
Where possible the B<EVP> interface to symmetric ciphers should be used in
-preference to the low level interfaces. This is because the code then becomes
+preference to the low-level interfaces. This is because the code then becomes
transparent to the cipher used and much more flexible. Additionally, the
B<EVP> interface will ensure the use of platform specific cryptographic
-acceleration such as AES-NI (the low level interfaces do not provide the
+acceleration such as AES-NI (the low-level interfaces do not provide the
guarantee).
PKCS padding works by adding B<n> padding bytes of value B<n> to make the total
/* Don't set key or IV right away; we want to check lengths */
ctx = EVP_CIPHER_CTX_new();
- EVP_CipherInit_ex(&ctx, EVP_aes_128_cbc(), NULL, NULL, NULL,
+ EVP_CipherInit_ex(ctx, EVP_aes_128_cbc(), NULL, NULL, NULL,
do_encrypt);
OPENSSL_assert(EVP_CIPHER_CTX_key_length(ctx) == 16);
OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) == 16);
=head1 COPYRIGHT
-Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2020 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