xref: /freebsd/crypto/openssl/doc/man3/EVP_CIPHER_meth_new.pod (revision 2e3507c25e42292b45a5482e116d278f5515d04d)
1=pod
2
3=head1 NAME
4
5EVP_CIPHER_meth_new, EVP_CIPHER_meth_dup, EVP_CIPHER_meth_free,
6EVP_CIPHER_meth_set_iv_length, EVP_CIPHER_meth_set_flags,
7EVP_CIPHER_meth_set_impl_ctx_size, EVP_CIPHER_meth_set_init,
8EVP_CIPHER_meth_set_do_cipher, EVP_CIPHER_meth_set_cleanup,
9EVP_CIPHER_meth_set_set_asn1_params, EVP_CIPHER_meth_set_get_asn1_params,
10EVP_CIPHER_meth_set_ctrl, EVP_CIPHER_meth_get_init,
11EVP_CIPHER_meth_get_do_cipher, EVP_CIPHER_meth_get_cleanup,
12EVP_CIPHER_meth_get_set_asn1_params, EVP_CIPHER_meth_get_get_asn1_params,
13EVP_CIPHER_meth_get_ctrl
14- Routines to build up EVP_CIPHER methods
15
16=head1 SYNOPSIS
17
18 #include <openssl/evp.h>
19
20The following functions have been deprecated since OpenSSL 3.0, and can be
21hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
22see L<openssl_user_macros(7)>:
23
24 EVP_CIPHER *EVP_CIPHER_meth_new(int cipher_type, int block_size, int key_len);
25 EVP_CIPHER *EVP_CIPHER_meth_dup(const EVP_CIPHER *cipher);
26 void EVP_CIPHER_meth_free(EVP_CIPHER *cipher);
27
28 int EVP_CIPHER_meth_set_iv_length(EVP_CIPHER *cipher, int iv_len);
29 int EVP_CIPHER_meth_set_flags(EVP_CIPHER *cipher, unsigned long flags);
30 int EVP_CIPHER_meth_set_impl_ctx_size(EVP_CIPHER *cipher, int ctx_size);
31 int EVP_CIPHER_meth_set_init(EVP_CIPHER *cipher,
32                              int (*init)(EVP_CIPHER_CTX *ctx,
33                                          const unsigned char *key,
34                                          const unsigned char *iv,
35                                          int enc));
36 int EVP_CIPHER_meth_set_do_cipher(EVP_CIPHER *cipher,
37                                   int (*do_cipher)(EVP_CIPHER_CTX *ctx,
38                                                    unsigned char *out,
39                                                    const unsigned char *in,
40                                                    size_t inl));
41 int EVP_CIPHER_meth_set_cleanup(EVP_CIPHER *cipher,
42                                 int (*cleanup)(EVP_CIPHER_CTX *));
43 int EVP_CIPHER_meth_set_set_asn1_params(EVP_CIPHER *cipher,
44                                         int (*set_asn1_parameters)(EVP_CIPHER_CTX *,
45                                                                    ASN1_TYPE *));
46 int EVP_CIPHER_meth_set_get_asn1_params(EVP_CIPHER *cipher,
47                                         int (*get_asn1_parameters)(EVP_CIPHER_CTX *,
48                                                                    ASN1_TYPE *));
49 int EVP_CIPHER_meth_set_ctrl(EVP_CIPHER *cipher,
50                              int (*ctrl)(EVP_CIPHER_CTX *, int type,
51                                          int arg, void *ptr));
52
53 int (*EVP_CIPHER_meth_get_init(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *ctx,
54                                                           const unsigned char *key,
55                                                           const unsigned char *iv,
56                                                           int enc);
57 int (*EVP_CIPHER_meth_get_do_cipher(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *ctx,
58                                                                unsigned char *out,
59                                                                const unsigned char *in,
60                                                                size_t inl);
61 int (*EVP_CIPHER_meth_get_cleanup(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *);
62 int (*EVP_CIPHER_meth_get_set_asn1_params(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *,
63                                                                      ASN1_TYPE *);
64 int (*EVP_CIPHER_meth_get_get_asn1_params(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *,
65                                                                      ASN1_TYPE *);
66 int (*EVP_CIPHER_meth_get_ctrl(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *,
67                                                           int type, int arg,
68                                                           void *ptr);
69
70=head1 DESCRIPTION
71
72All of the functions described on this page are deprecated.
73Applications should instead use the OSSL_PROVIDER APIs.
74
75The B<EVP_CIPHER> type is a structure for symmetric cipher method
76implementation.
77
78EVP_CIPHER_meth_new() creates a new B<EVP_CIPHER> structure.
79
80EVP_CIPHER_meth_dup() creates a copy of B<cipher>.
81
82EVP_CIPHER_meth_free() destroys a B<EVP_CIPHER> structure.
83
84EVP_CIPHER_meth_set_iv_length() sets the length of the IV.
85This is only needed when the implemented cipher mode requires it.
86
87EVP_CIPHER_meth_set_flags() sets the flags to describe optional
88behaviours in the particular B<cipher>.
89With the exception of cipher modes, of which only one may be present,
90several flags can be or'd together.
91The available flags are:
92
93=over 4
94
95=item EVP_CIPH_STREAM_CIPHER, EVP_CIPH_ECB_MODE EVP_CIPH_CBC_MODE,
96EVP_CIPH_CFB_MODE, EVP_CIPH_OFB_MODE, EVP_CIPH_CTR_MODE, EVP_CIPH_GCM_MODE,
97EVP_CIPH_CCM_MODE, EVP_CIPH_XTS_MODE, EVP_CIPH_WRAP_MODE,
98EVP_CIPH_OCB_MODE, EVP_CIPH_SIV_MODE
99
100The cipher mode.
101
102=item EVP_CIPH_VARIABLE_LENGTH
103
104This cipher is of variable length.
105
106=item EVP_CIPH_CUSTOM_IV
107
108Storing and initialising the IV is left entirely to the
109implementation.
110
111=item EVP_CIPH_ALWAYS_CALL_INIT
112
113Set this if the implementation's init() function should be called even
114if B<key> is B<NULL>.
115
116=item EVP_CIPH_CTRL_INIT
117
118Set this to have the implementation's ctrl() function called with
119command code B<EVP_CTRL_INIT> early in its setup.
120
121=item EVP_CIPH_CUSTOM_KEY_LENGTH
122
123Checking and setting the key length after creating the B<EVP_CIPHER>
124is left to the implementation.
125Whenever someone uses EVP_CIPHER_CTX_set_key_length() on a
126B<EVP_CIPHER> with this flag set, the implementation's ctrl() function
127will be called with the control code B<EVP_CTRL_SET_KEY_LENGTH> and
128the key length in B<arg>.
129
130=item EVP_CIPH_NO_PADDING
131
132Don't use standard block padding.
133
134=item EVP_CIPH_RAND_KEY
135
136Making a key with random content is left to the implementation.
137This is done by calling the implementation's ctrl() function with the
138control code B<EVP_CTRL_RAND_KEY> and the pointer to the key memory
139storage in B<ptr>.
140
141=item EVP_CIPH_CUSTOM_COPY
142
143Set this to have the implementation's ctrl() function called with
144command code B<EVP_CTRL_COPY> at the end of EVP_CIPHER_CTX_copy().
145The intended use is for further things to deal with after the
146implementation specific data block has been copied.
147The destination B<EVP_CIPHER_CTX> is passed to the control with the
148B<ptr> parameter.
149The implementation specific data block is reached with
150EVP_CIPHER_CTX_get_cipher_data().
151
152=item EVP_CIPH_FLAG_DEFAULT_ASN1
153
154Use the default EVP routines to pass IV to and from ASN.1.
155
156=item EVP_CIPH_FLAG_LENGTH_BITS
157
158Signals that the length of the input buffer for encryption /
159decryption is to be understood as the number of bits instead of
160bytes for this implementation.
161This is only useful for CFB1 ciphers.
162
163=item EVP_CIPH_FLAG_CTS
164
165Indicates that the cipher uses ciphertext stealing. This is currently
166used to indicate that the cipher is a one shot that only allows a single call to
167EVP_CipherUpdate().
168
169=item EVP_CIPH_FLAG_CUSTOM_CIPHER
170
171This indicates that the implementation takes care of everything,
172including padding, buffering and finalization.
173The EVP routines will simply give them control and do nothing more.
174
175=item EVP_CIPH_FLAG_AEAD_CIPHER
176
177This indicates that this is an AEAD cipher implementation.
178
179=item EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK
180
181Allow interleaving of crypto blocks, a particular optimization only applicable
182to certain TLS ciphers.
183
184=back
185
186EVP_CIPHER_meth_set_impl_ctx_size() sets the size of the EVP_CIPHER's
187implementation context so that it can be automatically allocated.
188
189EVP_CIPHER_meth_set_init() sets the cipher init function for
190B<cipher>.
191The cipher init function is called by EVP_CipherInit(),
192EVP_CipherInit_ex(), EVP_EncryptInit(), EVP_EncryptInit_ex(),
193EVP_DecryptInit(), EVP_DecryptInit_ex().
194
195EVP_CIPHER_meth_set_do_cipher() sets the cipher function for
196B<cipher>.
197The cipher function is called by EVP_CipherUpdate(),
198EVP_EncryptUpdate(), EVP_DecryptUpdate(), EVP_CipherFinal(),
199EVP_EncryptFinal(), EVP_EncryptFinal_ex(), EVP_DecryptFinal() and
200EVP_DecryptFinal_ex().
201
202EVP_CIPHER_meth_set_cleanup() sets the function for B<cipher> to do
203extra cleanup before the method's private data structure is cleaned
204out and freed.
205Note that the cleanup function is passed a B<EVP_CIPHER_CTX *>, the
206private data structure is then available with
207EVP_CIPHER_CTX_get_cipher_data().
208This cleanup function is called by EVP_CIPHER_CTX_reset() and
209EVP_CIPHER_CTX_free().
210
211EVP_CIPHER_meth_set_set_asn1_params() sets the function for B<cipher>
212to set the AlgorithmIdentifier "parameter" based on the passed cipher.
213This function is called by EVP_CIPHER_param_to_asn1().
214EVP_CIPHER_meth_set_get_asn1_params() sets the function for B<cipher>
215that sets the cipher parameters based on an ASN.1 AlgorithmIdentifier
216"parameter".
217Both these functions are needed when there is a need for custom data
218(more or other than the cipher IV).
219They are called by EVP_CIPHER_param_to_asn1() and
220EVP_CIPHER_asn1_to_param() respectively if defined.
221
222EVP_CIPHER_meth_set_ctrl() sets the control function for B<cipher>.
223
224EVP_CIPHER_meth_get_init(), EVP_CIPHER_meth_get_do_cipher(),
225EVP_CIPHER_meth_get_cleanup(), EVP_CIPHER_meth_get_set_asn1_params(),
226EVP_CIPHER_meth_get_get_asn1_params() and EVP_CIPHER_meth_get_ctrl()
227are all used to retrieve the method data given with the
228EVP_CIPHER_meth_set_*() functions above.
229
230=head1 RETURN VALUES
231
232EVP_CIPHER_meth_new() and EVP_CIPHER_meth_dup() return a pointer to a
233newly created B<EVP_CIPHER>, or NULL on failure.
234All EVP_CIPHER_meth_set_*() functions return 1.
235All EVP_CIPHER_meth_get_*() functions return pointers to their
236respective B<cipher> function.
237
238=head1 SEE ALSO
239
240L<EVP_EncryptInit(3)>
241
242=head1 HISTORY
243
244All of these functions were deprecated in OpenSSL 3.0.
245
246The functions described here were added in OpenSSL 1.1.0.
247The B<EVP_CIPHER> structure created with these functions became reference
248counted in OpenSSL 3.0.
249
250=head1 COPYRIGHT
251
252Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
253
254Licensed under the Apache License 2.0 (the "License").  You may not use
255this file except in compliance with the License.  You can obtain a copy
256in the file LICENSE in the source distribution or at
257L<https://www.openssl.org/source/license.html>.
258
259=cut
260