1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
|
=pod
=head1 NAME
EVP_CIPHER_meth_new, EVP_CIPHER_meth_dup, EVP_CIPHER_meth_free,
EVP_CIPHER_meth_set_iv_length, EVP_CIPHER_meth_set_flags,
EVP_CIPHER_meth_set_impl_ctx_size, EVP_CIPHER_meth_set_init,
EVP_CIPHER_meth_set_do_cipher, EVP_CIPHER_meth_set_cleanup,
EVP_CIPHER_meth_set_set_asn1_params, EVP_CIPHER_meth_set_get_asn1_params,
EVP_CIPHER_meth_set_ctrl, EVP_CIPHER_meth_get_init,
EVP_CIPHER_meth_get_do_cipher, EVP_CIPHER_meth_get_cleanup,
EVP_CIPHER_meth_get_set_asn1_params, EVP_CIPHER_meth_get_get_asn1_params,
EVP_CIPHER_meth_get_ctrl - Routines to build up EVP_CIPHER methods
=head1 SYNOPSIS
#include <openssl/evp.h>
EVP_CIPHER *EVP_CIPHER_meth_new(int cipher_type, int block_size, int key_len);
EVP_CIPHER *EVP_CIPHER_meth_dup(const EVP_CIPHER *cipher);
void EVP_CIPHER_meth_free(EVP_CIPHER *cipher);
int EVP_CIPHER_meth_set_iv_length(EVP_CIPHER *cipher, int iv_len);
int EVP_CIPHER_meth_set_flags(EVP_CIPHER *cipher, unsigned long flags);
int EVP_CIPHER_meth_set_impl_ctx_size(EVP_CIPHER *cipher, int ctx_size);
int EVP_CIPHER_meth_set_init(EVP_CIPHER *cipher,
int (*init) (EVP_CIPHER_CTX *ctx,
const unsigned char *key,
const unsigned char *iv,
int enc));
int EVP_CIPHER_meth_set_do_cipher(EVP_CIPHER *cipher,
int (*do_cipher) (EVP_CIPHER_CTX *ctx,
unsigned char *out,
const unsigned char *in,
size_t inl));
int EVP_CIPHER_meth_set_cleanup(EVP_CIPHER *cipher,
int (*cleanup) (EVP_CIPHER_CTX *));
int EVP_CIPHER_meth_set_set_asn1_params(EVP_CIPHER *cipher,
int (*set_asn1_parameters) (EVP_CIPHER_CTX *,
ASN1_TYPE *));
int EVP_CIPHER_meth_set_get_asn1_params(EVP_CIPHER *cipher,
int (*get_asn1_parameters) (EVP_CIPHER_CTX *,
ASN1_TYPE *));
int EVP_CIPHER_meth_set_ctrl(EVP_CIPHER *cipher,
int (*ctrl) (EVP_CIPHER_CTX *, int type,
int arg, void *ptr));
int (*EVP_CIPHER_meth_get_init(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *ctx,
const unsigned char *key,
const unsigned char *iv,
int enc);
int (*EVP_CIPHER_meth_get_do_cipher(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *ctx,
unsigned char *out,
const unsigned char *in,
size_t inl);
int (*EVP_CIPHER_meth_get_cleanup(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *);
int (*EVP_CIPHER_meth_get_set_asn1_params(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *,
ASN1_TYPE *);
int (*EVP_CIPHER_meth_get_get_asn1_params(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *,
ASN1_TYPE *);
int (*EVP_CIPHER_meth_get_ctrl(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *,
int type, int arg,
void *ptr);
=head1 DESCRIPTION
The B<EVP_CIPHER> type is a structure for symmetric cipher method
implementation.
EVP_CIPHER_meth_new() creates a new B<EVP_CIPHER> structure.
EVP_CIPHER_meth_dup() creates a copy of B<cipher>.
EVP_CIPHER_meth_free() destroys a B<EVP_CIPHER> structure.
EVP_CIPHER_meth_iv_length() sets the length of the IV.
This is only needed when the implemented cipher mode requires it.
EVP_CIPHER_meth_set_flags() sets the flags to describe optional
behaviours in the particular B<cipher>.
With the exception of cipher modes, of which only one may be present,
several flags can be or'd together.
The available flags are:
=over 4
=item EVP_CIPH_STREAM_CIPHER, EVP_CIPH_ECB_MODE EVP_CIPH_CBC_MODE,
EVP_CIPH_CFB_MODE, EVP_CIPH_OFB_MODE, EVP_CIPH_CTR_MODE, EVP_CIPH_GCM_MODE,
EVP_CIPH_CCM_MODE, EVP_CIPH_XTS_MODE, EVP_CIPH_WRAP_MODE,
EVP_CIPH_OCB_MODE
The cipher mode.
=item EVP_CIPH_VARIABLE_LENGTH
This cipher is of variable length.
=item EVP_CIPH_CUSTOM_IV
Storing and initialising the IV is left entirely to the
implementation.
=item EVP_CIPH_ALWAYS_CALL_INIT
Set this if the implementation's init() function should be called even
if B<key> is B<NULL>.
=item EVP_CIPH_CTRL_INIT
Set this to have the implementation's ctrl() function called with
command code B<EVP_CTRL_INIT> early in its setup.
=item EVP_CIPH_CUSTOM_KEY_LENGTH
Checking and setting the key length after creating the B<EVP_CIPHER>
is left to the implementation.
Whenever someone uses EVP_CIPHER_CTX_set_key_length() on a
B<EVP_CIPHER> with this flag set, the implementation's ctrl() function
will be called with the control code B<EVP_CTRL_SET_KEY_LENGTH> and
the key length in B<arg>.
=item EVP_CIPH_NO_PADDING
Don't use standard block padding.
=item EVP_CIPH_RAND_KEY
Making a key with random content is left to the implementation.
This is done by calling the implementation's ctrl() function with the
control code B<EVP_CTRL_RAND_KEY> and the pointer to the key memory
storage in B<ptr>.
=item EVP_CIPH_CUSTOM_COPY
Set this to have the implementation's ctrl() function called with
command code B<EVP_CTRL_COPY> at the end of EVP_CIPHER_CTX_copy().
The intended use is for further things to deal with after the
implementation specific data block has been copied.
The destination B<EVP_CIPHER_CTX> is passed to the control with the
B<ptr> parameter.
The implementation specific data block is reached with
EVP_CIPHER_CTX_get_cipher_data().
=item EVP_CIPH_FLAG_DEFAULT_ASN1
Use the default EVP routines to pass IV to and from ASN.1.
=item EVP_CIPH_FLAG_LENGTH_BITS
Signals that the length of the input buffer for encryption /
decryption is to be understood as the number of bits bits instead of
bytes for this implementation.
This is only useful for CFB1 ciphers.
=begin comment
The FIPS flags seem to be unused, so I'm hiding them until I get an
explanation or they get removed. /RL
=item EVP_CIPH_FLAG_FIPS
=item EVP_CIPH_FLAG_NON_FIPS_ALLOW
=end comment
=item EVP_CIPH_FLAG_CUSTOM_CIPHER
This indicates that the implementation takes care of everything,
including padding, buffering and finalization.
The EVP routines will simply give them control and do nothing more.
=item EVP_CIPH_FLAG_AEAD_CIPHER
This indicates that this is an AEAD cipher implementation.
=item EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK
Allow interleaving of crypto blocks, a particular optimization only applicable
to certain TLS ciphers.
=back
EVP_CIPHER_meth_set_impl_ctx_size() sets the size of the EVP_CIPHER's
implementation context so that it can be automatically allocated.
EVP_CIPHER_meth_set_init() sets the cipher init function for
B<cipher>.
The cipher init function is called by EVP_CipherInit(),
EVP_CipherInit_ex(), EVP_EncryptInit(), EVP_EncryptInit_ex(),
EVP_DecryptInit(), EVP_DecryptInit_ex().
EVP_CIPHER_meth_set_do_cipher() sets the cipher function for
B<cipher>.
The cipher function is called by EVP_CipherUpdate(),
EVP_EncryptUpdate(), EVP_DecryptUpdate(), EVP_CipherFinal(),
EVP_EncryptFinal(), EVP_EncryptFinal_ex(), EVP_DecryptFinal() and
EVP_DecryptFinal_ex().
EVP_CIPHER_meth_set_cleanup() sets the function for B<cipher> to do
extra cleanup before the method's private data structure is cleaned
out and freed.
Note that the cleanup function is passed a B<EVP_CIPHER_CTX *>, the
private data structure is then available with
EVP_CIPHER_CTX_get_cipher_data().
This cleanup function is called by EVP_CIPHER_CTX_reset() and
EVP_CIPHER_CTX_free().
EVP_CIPHER_meth_set_set_asn1_params() sets the function for B<cipher>
to set the AlgorithmIdentifier "parameter" based on the passed cipher.
This function is called by EVP_CIPHER_param_to_asn1().
EVP_CIPHER_meth_set_get_asn1_params() sets the function for B<cipher>
that sets the cipher parameters based on an ASN.1 AlgorithmIdentifier
"parameter".
Both these functions are needed when there is a need for custom data
(more or other than the cipher IV).
They are called by EVP_CIPHER_param_to_asn1() and
EVP_CIPHER_asn1_to_param() respectively if defined.
EVP_CIPHER_meth_set_ctrl() sets the control function for B<cipher>.
EVP_CIPHER_meth_get_init(), EVP_CIPHER_meth_get_do_cipher(),
EVP_CIPHER_meth_get_cleanup(), EVP_CIPHER_meth_get_set_asn1_params(),
EVP_CIPHER_meth_get_get_asn1_params() and EVP_CIPHER_meth_get_ctrl()
are all used to retrieve the method data given with the
EVP_CIPHER_meth_set_*() functions above.
=head1 RETURN VALUES
EVP_CIPHER_meth_new() and EVP_CIPHER_meth_dup() return a pointer to a
newly created B<EVP_CIPHER>, or NULL on failure.
All EVP_CIPHER_meth_set_*() functions return 1.
All EVP_CIPHER_meth_get_*() functions return pointers to their
respective B<cipher> function.
=head1 SEE ALSO
L<EVP_EncryptInit>
=head1 HISTORY
The B<EVP_CIPHER> structure was openly available in OpenSSL before version
1.1.0.
The functions described here were added in OpenSSL 1.1.0.
=head1 COPYRIGHT
Copyright 2016-2017 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
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.
=cut
|
