EVP_EncryptInit_ex() sets up cipher context B<ctx> for encryption
with cipher B<type> from ENGINE B<impl>. B<ctx> must be initialized
before calling this function. B<type> is normally supplied
-by a function such as EVP_des_cbc(). If B<impl> is NULL then the
+by a function such as EVP_aes_256_cbc(). If B<impl> is NULL then the
default implementation is used. B<key> is the symmetric key to use
and B<iv> is the IV to use (if necessary), the actual number of bytes
used for the key and IV depends on the cipher. It is possible to set
If padding is enabled (the default) then EVP_EncryptFinal_ex() encrypts
the "final" data, that is any data that remains in a partial block.
-It uses L<standard block padding|/NOTES> (aka PKCS padding). The encrypted
+It uses standard block padding (aka PKCS padding) as described in
+the NOTES section, below. The encrypted
final data is written to B<out> which should have sufficient space for
one cipher block. The number of bytes written is placed in B<outl>. After
this function is called the encryption operation is finished and no further
EVP_CIPHER_CTX_cipher() returns an B<EVP_CIPHER> structure.
-EVP_CIPHER_param_to_asn1() and EVP_CIPHER_asn1_to_param() return 1 for
-success or zero for failure.
+EVP_CIPHER_param_to_asn1() and EVP_CIPHER_asn1_to_param() return greater
+than zero for success and zero or a negative number.
=head1 CIPHER LISTING
the authentication operation has failed and any output data B<MUST NOT>
be used as it is corrupted.
-The following ctrl is supported in OCB mode only:
-
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_OCB_SET_TAGLEN, taglen, NULL);
-
-Sets the tag length: this call can only be made before specifying an IV. If
-not called a default tag length is used. For OCB AES the default is 16 (i.e. 128
-bits). This is also the maximum tag length.
-
The following ctrls are supported in both GCM and OCB modes:
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_IVLEN, ivlen, NULL);
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL);
Sets the IV length: this call can only be made before specifying an IV. If
not called a default IV length is used. For GCM AES and OCB AES the default is
12 (i.e. 96 bits). For OCB mode the maximum is 15.
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_TAG, taglen, tag);
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen, tag);
Writes B<taglen> bytes of the tag value to the buffer indicated by B<tag>.
This call can only be made when encrypting data and B<after> all data has been
processed (e.g. after an EVP_EncryptFinal() call). For OCB mode the taglen must
either be 16 or the value previously set via EVP_CTRL_OCB_SET_TAGLEN.
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_TAG, taglen, tag);
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen, tag);
Sets the expected tag to B<taglen> bytes from B<tag>. This call is only legal
when decrypting data and must be made B<before> any data is processed (e.g.
before any EVP_DecryptUpdate() call). For OCB mode the taglen must
-either be 16 or the value previously set via EVP_CTRL_OCB_SET_TAGLEN.
+either be 16 or the value previously set via EVP_CTRL_AEAD_SET_TAG.
+
+In OCB mode calling this with B<tag> set to NULL sets the tag length. The tag
+length can only be set before specifying an IV. If not called a default tag
+length is used. For OCB AES the default is 16 (i.e. 128 bits). This is also the
+maximum tag length for OCB.
See L<EXAMPLES> below for an example of the use of GCM mode.
=head1 CCM Mode
-The behaviour of CCM mode ciphers is similar to CCM mode but with a few
+The behaviour of CCM mode ciphers is similar to GCM mode but with a few
additional requirements and different ctrl values.
Like GCM and OCB modes any additional authenticated data (AAD) is passed by calling
The following ctrls are supported in CCM mode:
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_TAG, taglen, tag);
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen, tag);
This call is made to set the expected B<CCM> tag value when decrypting or
the length of the tag (with the B<tag> parameter set to NULL) when encrypting.
Sets the CCM B<L> value. If not set a default is used (8 for AES).
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_IVLEN, ivlen, NULL);
+ 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
=head1 SEE ALSO
-L<evp(3)|evp(3)>
+L<evp(3)>
=head1 HISTORY
-EVP_CIPHER_CTX_init(), EVP_EncryptInit_ex(), EVP_EncryptFinal_ex(),
-EVP_DecryptInit_ex(), EVP_DecryptFinal_ex(), EVP_CipherInit_ex(),
-EVP_CipherFinal_ex() and EVP_CIPHER_CTX_set_padding() appeared in
-OpenSSL 0.9.7.
-
-IDEA appeared in OpenSSL 0.9.7 but was often disabled due to
-patent concerns; the last patents expired in 2012.
-
Support for OCB mode was added in OpenSSL 1.1.0
+
=cut
projects / openssl.git / blobdiff