5 EVP_CIPHER_meth_new, EVP_CIPHER_meth_dup, EVP_CIPHER_meth_free,
6 EVP_CIPHER_meth_set_iv_length, EVP_CIPHER_meth_set_flags,
7 EVP_CIPHER_meth_set_impl_ctx_size, EVP_CIPHER_meth_set_init,
8 EVP_CIPHER_meth_set_do_cipher, EVP_CIPHER_meth_set_cleanup,
9 EVP_CIPHER_meth_set_set_asn1_params, EVP_CIPHER_meth_set_get_asn1_params,
10 EVP_CIPHER_meth_set_ctrl, EVP_CIPHER_meth_get_init,
11 EVP_CIPHER_meth_get_do_cipher, EVP_CIPHER_meth_get_cleanup,
12 EVP_CIPHER_meth_get_set_asn1_params, EVP_CIPHER_meth_get_get_asn1_params,
13 EVP_CIPHER_meth_get_ctrl
14 - Routines to build up EVP_CIPHER methods
18 #include <openssl/evp.h>
20 EVP_CIPHER *EVP_CIPHER_meth_new(int cipher_type, int block_size, int key_len);
21 EVP_CIPHER *EVP_CIPHER_meth_dup(const EVP_CIPHER *cipher);
22 void EVP_CIPHER_meth_free(EVP_CIPHER *cipher);
24 int EVP_CIPHER_meth_set_iv_length(EVP_CIPHER *cipher, int iv_len);
25 int EVP_CIPHER_meth_set_flags(EVP_CIPHER *cipher, unsigned long flags);
26 int EVP_CIPHER_meth_set_impl_ctx_size(EVP_CIPHER *cipher, int ctx_size);
27 int EVP_CIPHER_meth_set_init(EVP_CIPHER *cipher,
28 int (*init)(EVP_CIPHER_CTX *ctx,
29 const unsigned char *key,
30 const unsigned char *iv,
32 int EVP_CIPHER_meth_set_do_cipher(EVP_CIPHER *cipher,
33 int (*do_cipher)(EVP_CIPHER_CTX *ctx,
35 const unsigned char *in,
37 int EVP_CIPHER_meth_set_cleanup(EVP_CIPHER *cipher,
38 int (*cleanup)(EVP_CIPHER_CTX *));
39 int EVP_CIPHER_meth_set_set_asn1_params(EVP_CIPHER *cipher,
40 int (*set_asn1_parameters)(EVP_CIPHER_CTX *,
42 int EVP_CIPHER_meth_set_get_asn1_params(EVP_CIPHER *cipher,
43 int (*get_asn1_parameters)(EVP_CIPHER_CTX *,
45 int EVP_CIPHER_meth_set_ctrl(EVP_CIPHER *cipher,
46 int (*ctrl)(EVP_CIPHER_CTX *, int type,
49 int (*EVP_CIPHER_meth_get_init(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *ctx,
50 const unsigned char *key,
51 const unsigned char *iv,
53 int (*EVP_CIPHER_meth_get_do_cipher(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *ctx,
55 const unsigned char *in,
57 int (*EVP_CIPHER_meth_get_cleanup(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *);
58 int (*EVP_CIPHER_meth_get_set_asn1_params(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *,
60 int (*EVP_CIPHER_meth_get_get_asn1_params(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *,
62 int (*EVP_CIPHER_meth_get_ctrl(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *,
68 The B<EVP_CIPHER> type is a structure for symmetric cipher method
71 EVP_CIPHER_meth_new() creates a new B<EVP_CIPHER> structure.
73 EVP_CIPHER_meth_dup() creates a copy of B<cipher>.
75 EVP_CIPHER_meth_free() destroys a B<EVP_CIPHER> structure.
77 EVP_CIPHER_meth_set_iv_length() sets the length of the IV.
78 This is only needed when the implemented cipher mode requires it.
80 EVP_CIPHER_meth_set_flags() sets the flags to describe optional
81 behaviours in the particular B<cipher>.
82 With the exception of cipher modes, of which only one may be present,
83 several flags can be or'd together.
84 The available flags are:
88 =item EVP_CIPH_STREAM_CIPHER, EVP_CIPH_ECB_MODE EVP_CIPH_CBC_MODE,
89 EVP_CIPH_CFB_MODE, EVP_CIPH_OFB_MODE, EVP_CIPH_CTR_MODE, EVP_CIPH_GCM_MODE,
90 EVP_CIPH_CCM_MODE, EVP_CIPH_XTS_MODE, EVP_CIPH_WRAP_MODE,
91 EVP_CIPH_OCB_MODE, EVP_CIPH_SIV_MODE
95 =item EVP_CIPH_VARIABLE_LENGTH
97 This cipher is of variable length.
99 =item EVP_CIPH_CUSTOM_IV
101 Storing and initialising the IV is left entirely to the
104 =item EVP_CIPH_ALWAYS_CALL_INIT
106 Set this if the implementation's init() function should be called even
107 if B<key> is B<NULL>.
109 =item EVP_CIPH_CTRL_INIT
111 Set this to have the implementation's ctrl() function called with
112 command code B<EVP_CTRL_INIT> early in its setup.
114 =item EVP_CIPH_CUSTOM_KEY_LENGTH
116 Checking and setting the key length after creating the B<EVP_CIPHER>
117 is left to the implementation.
118 Whenever someone uses EVP_CIPHER_CTX_set_key_length() on a
119 B<EVP_CIPHER> with this flag set, the implementation's ctrl() function
120 will be called with the control code B<EVP_CTRL_SET_KEY_LENGTH> and
121 the key length in B<arg>.
123 =item EVP_CIPH_NO_PADDING
125 Don't use standard block padding.
127 =item EVP_CIPH_RAND_KEY
129 Making a key with random content is left to the implementation.
130 This is done by calling the implementation's ctrl() function with the
131 control code B<EVP_CTRL_RAND_KEY> and the pointer to the key memory
134 =item EVP_CIPH_CUSTOM_COPY
136 Set this to have the implementation's ctrl() function called with
137 command code B<EVP_CTRL_COPY> at the end of EVP_CIPHER_CTX_copy().
138 The intended use is for further things to deal with after the
139 implementation specific data block has been copied.
140 The destination B<EVP_CIPHER_CTX> is passed to the control with the
142 The implementation specific data block is reached with
143 EVP_CIPHER_CTX_get_cipher_data().
145 =item EVP_CIPH_FLAG_DEFAULT_ASN1
147 Use the default EVP routines to pass IV to and from ASN.1.
149 =item EVP_CIPH_FLAG_LENGTH_BITS
151 Signals that the length of the input buffer for encryption /
152 decryption is to be understood as the number of bits instead of
153 bytes for this implementation.
154 This is only useful for CFB1 ciphers.
156 =item EVP_CIPH_FLAG_CTS
158 Indicates that the cipher uses ciphertext stealing. This is currently
159 used to indicate that the cipher is a one shot that only allows a single call to
162 =item EVP_CIPH_FLAG_CUSTOM_CIPHER
164 This indicates that the implementation takes care of everything,
165 including padding, buffering and finalization.
166 The EVP routines will simply give them control and do nothing more.
168 =item EVP_CIPH_FLAG_AEAD_CIPHER
170 This indicates that this is an AEAD cipher implementation.
172 =item EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK
174 Allow interleaving of crypto blocks, a particular optimization only applicable
175 to certain TLS ciphers.
179 EVP_CIPHER_meth_set_impl_ctx_size() sets the size of the EVP_CIPHER's
180 implementation context so that it can be automatically allocated.
182 EVP_CIPHER_meth_set_init() sets the cipher init function for
184 The cipher init function is called by EVP_CipherInit(),
185 EVP_CipherInit_ex(), EVP_EncryptInit(), EVP_EncryptInit_ex(),
186 EVP_DecryptInit(), EVP_DecryptInit_ex().
188 EVP_CIPHER_meth_set_do_cipher() sets the cipher function for
190 The cipher function is called by EVP_CipherUpdate(),
191 EVP_EncryptUpdate(), EVP_DecryptUpdate(), EVP_CipherFinal(),
192 EVP_EncryptFinal(), EVP_EncryptFinal_ex(), EVP_DecryptFinal() and
193 EVP_DecryptFinal_ex().
195 EVP_CIPHER_meth_set_cleanup() sets the function for B<cipher> to do
196 extra cleanup before the method's private data structure is cleaned
198 Note that the cleanup function is passed a B<EVP_CIPHER_CTX *>, the
199 private data structure is then available with
200 EVP_CIPHER_CTX_get_cipher_data().
201 This cleanup function is called by EVP_CIPHER_CTX_reset() and
202 EVP_CIPHER_CTX_free().
204 EVP_CIPHER_meth_set_set_asn1_params() sets the function for B<cipher>
205 to set the AlgorithmIdentifier "parameter" based on the passed cipher.
206 This function is called by EVP_CIPHER_param_to_asn1().
207 EVP_CIPHER_meth_set_get_asn1_params() sets the function for B<cipher>
208 that sets the cipher parameters based on an ASN.1 AlgorithmIdentifier
210 Both these functions are needed when there is a need for custom data
211 (more or other than the cipher IV).
212 They are called by EVP_CIPHER_param_to_asn1() and
213 EVP_CIPHER_asn1_to_param() respectively if defined.
215 EVP_CIPHER_meth_set_ctrl() sets the control function for B<cipher>.
217 EVP_CIPHER_meth_get_init(), EVP_CIPHER_meth_get_do_cipher(),
218 EVP_CIPHER_meth_get_cleanup(), EVP_CIPHER_meth_get_set_asn1_params(),
219 EVP_CIPHER_meth_get_get_asn1_params() and EVP_CIPHER_meth_get_ctrl()
220 are all used to retrieve the method data given with the
221 EVP_CIPHER_meth_set_*() functions above.
225 EVP_CIPHER_meth_new() and EVP_CIPHER_meth_dup() return a pointer to a
226 newly created B<EVP_CIPHER>, or NULL on failure.
227 All EVP_CIPHER_meth_set_*() functions return 1.
228 All EVP_CIPHER_meth_get_*() functions return pointers to their
229 respective B<cipher> function.
233 L<EVP_EncryptInit(3)>
237 The functions described here were added in OpenSSL 1.1.0.
238 The B<EVP_CIPHER> structure created with these functions became reference
239 counted in OpenSSL 3.0.
243 Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
245 Licensed under the Apache License 2.0 (the "License"). You may not use
246 this file except in compliance with the License. You can obtain a copy
247 in the file LICENSE in the source distribution or at
248 L<https://www.openssl.org/source/license.html>.