1=pod
2
3=head1 NAME
4
5RSA_meth_get0_app_data, RSA_meth_set0_app_data,
6RSA_meth_new, RSA_meth_free, RSA_meth_dup, RSA_meth_get0_name,
7RSA_meth_set1_name, RSA_meth_get_flags, RSA_meth_set_flags,
8RSA_meth_get_pub_enc,
9RSA_meth_set_pub_enc, RSA_meth_get_pub_dec, RSA_meth_set_pub_dec,
10RSA_meth_get_priv_enc, RSA_meth_set_priv_enc, RSA_meth_get_priv_dec,
11RSA_meth_set_priv_dec, RSA_meth_get_mod_exp, RSA_meth_set_mod_exp,
12RSA_meth_get_bn_mod_exp, RSA_meth_set_bn_mod_exp, RSA_meth_get_init,
13RSA_meth_set_init, RSA_meth_get_finish, RSA_meth_set_finish,
14RSA_meth_get_sign, RSA_meth_set_sign, RSA_meth_get_verify,
15RSA_meth_set_verify, RSA_meth_get_keygen, RSA_meth_set_keygen,
16RSA_meth_get_multi_prime_keygen, RSA_meth_set_multi_prime_keygen
17- Routines to build up RSA methods
18
19=head1 SYNOPSIS
20
21 #include <openssl/rsa.h>
22
23 RSA_METHOD *RSA_meth_new(const char *name, int flags);
24 void RSA_meth_free(RSA_METHOD *meth);
25
26 RSA_METHOD *RSA_meth_dup(const RSA_METHOD *meth);
27
28 const char *RSA_meth_get0_name(const RSA_METHOD *meth);
29 int RSA_meth_set1_name(RSA_METHOD *meth, const char *name);
30
31 int RSA_meth_get_flags(const RSA_METHOD *meth);
32 int RSA_meth_set_flags(RSA_METHOD *meth, int flags);
33
34 void *RSA_meth_get0_app_data(const RSA_METHOD *meth);
35 int RSA_meth_set0_app_data(RSA_METHOD *meth, void *app_data);
36
37 int (*RSA_meth_get_pub_enc(const RSA_METHOD *meth))(int flen, const unsigned char *from,
38                                                     unsigned char *to, RSA *rsa, int padding);
39 int RSA_meth_set_pub_enc(RSA_METHOD *rsa,
40                          int (*pub_enc)(int flen, const unsigned char *from,
41                                         unsigned char *to, RSA *rsa,
42                                         int padding));
43
44 int (*RSA_meth_get_pub_dec(const RSA_METHOD *meth))
45     (int flen, const unsigned char *from,
46      unsigned char *to, RSA *rsa, int padding);
47 int RSA_meth_set_pub_dec(RSA_METHOD *rsa,
48                          int (*pub_dec)(int flen, const unsigned char *from,
49                                         unsigned char *to, RSA *rsa,
50                                         int padding));
51
52 int (*RSA_meth_get_priv_enc(const RSA_METHOD *meth))(int flen, const unsigned char *from,
53                                                      unsigned char *to, RSA *rsa,
54                                                      int padding);
55 int RSA_meth_set_priv_enc(RSA_METHOD *rsa,
56                           int (*priv_enc)(int flen, const unsigned char *from,
57                                           unsigned char *to, RSA *rsa, int padding));
58
59 int (*RSA_meth_get_priv_dec(const RSA_METHOD *meth))(int flen, const unsigned char *from,
60                                                      unsigned char *to, RSA *rsa,
61                                                      int padding);
62 int RSA_meth_set_priv_dec(RSA_METHOD *rsa,
63                           int (*priv_dec)(int flen, const unsigned char *from,
64                                           unsigned char *to, RSA *rsa, int padding));
65
66 /* Can be null */
67 int (*RSA_meth_get_mod_exp(const RSA_METHOD *meth))(BIGNUM *r0, const BIGNUM *i,
68                                                     RSA *rsa, BN_CTX *ctx);
69 int RSA_meth_set_mod_exp(RSA_METHOD *rsa,
70                          int (*mod_exp)(BIGNUM *r0, const BIGNUM *i, RSA *rsa,
71                                         BN_CTX *ctx));
72
73 /* Can be null */
74 int (*RSA_meth_get_bn_mod_exp(const RSA_METHOD *meth))(BIGNUM *r, const BIGNUM *a,
75                                                        const BIGNUM *p, const BIGNUM *m,
76                                                        BN_CTX *ctx, BN_MONT_CTX *m_ctx);
77 int RSA_meth_set_bn_mod_exp(RSA_METHOD *rsa,
78                             int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a,
79                                               const BIGNUM *p, const BIGNUM *m,
80                                               BN_CTX *ctx, BN_MONT_CTX *m_ctx));
81
82 /* called at new */
83 int (*RSA_meth_get_init(const RSA_METHOD *meth) (RSA *rsa);
84 int RSA_meth_set_init(RSA_METHOD *rsa, int (*init (RSA *rsa));
85
86 /* called at free */
87 int (*RSA_meth_get_finish(const RSA_METHOD *meth))(RSA *rsa);
88 int RSA_meth_set_finish(RSA_METHOD *rsa, int (*finish)(RSA *rsa));
89
90 int (*RSA_meth_get_sign(const RSA_METHOD *meth))(int type, const unsigned char *m,
91                                                  unsigned int m_length,
92                                                  unsigned char *sigret,
93                                                  unsigned int *siglen, const RSA *rsa);
94 int RSA_meth_set_sign(RSA_METHOD *rsa,
95                       int (*sign)(int type, const unsigned char *m,
96                                   unsigned int m_length, unsigned char *sigret,
97                                   unsigned int *siglen, const RSA *rsa));
98
99 int (*RSA_meth_get_verify(const RSA_METHOD *meth))(int dtype, const unsigned char *m,
100                                                    unsigned int m_length,
101                                                    const unsigned char *sigbuf,
102                                                    unsigned int siglen, const RSA *rsa);
103 int RSA_meth_set_verify(RSA_METHOD *rsa,
104                         int (*verify)(int dtype, const unsigned char *m,
105                                       unsigned int m_length,
106                                       const unsigned char *sigbuf,
107                                       unsigned int siglen, const RSA *rsa));
108
109 int (*RSA_meth_get_keygen(const RSA_METHOD *meth))(RSA *rsa, int bits, BIGNUM *e,
110                                                    BN_GENCB *cb);
111 int RSA_meth_set_keygen(RSA_METHOD *rsa,
112                         int (*keygen)(RSA *rsa, int bits, BIGNUM *e,
113                                       BN_GENCB *cb));
114
115 int (*RSA_meth_get_multi_prime_keygen(const RSA_METHOD *meth))(RSA *rsa, int bits,
116                                                                int primes, BIGNUM *e,
117                                                                BN_GENCB *cb);
118
119 int RSA_meth_set_multi_prime_keygen(RSA_METHOD *meth,
120                                     int (*keygen) (RSA *rsa, int bits,
121                                                    int primes, BIGNUM *e,
122                                                    BN_GENCB *cb));
123
124=head1 DESCRIPTION
125
126The B<RSA_METHOD> type is a structure used for the provision of custom
127RSA implementations. It provides a set of functions used by OpenSSL
128for the implementation of the various RSA capabilities. See the L<rsa>
129page for more information.
130
131RSA_meth_new() creates a new B<RSA_METHOD> structure. It should be
132given a unique B<name> and a set of B<flags>. The B<name> should be a
133NULL terminated string, which will be duplicated and stored in the
134B<RSA_METHOD> object. It is the callers responsibility to free the
135original string. The flags will be used during the construction of a
136new B<RSA> object based on this B<RSA_METHOD>. Any new B<RSA> object
137will have those flags set by default.
138
139RSA_meth_dup() creates a duplicate copy of the B<RSA_METHOD> object
140passed as a parameter. This might be useful for creating a new
141B<RSA_METHOD> based on an existing one, but with some differences.
142
143RSA_meth_free() destroys an B<RSA_METHOD> structure and frees up any
144memory associated with it.
145
146RSA_meth_get0_name() will return a pointer to the name of this
147RSA_METHOD. This is a pointer to the internal name string and so
148should not be freed by the caller. RSA_meth_set1_name() sets the name
149of the RSA_METHOD to B<name>. The string is duplicated and the copy is
150stored in the RSA_METHOD structure, so the caller remains responsible
151for freeing the memory associated with the name.
152
153RSA_meth_get_flags() returns the current value of the flags associated
154with this RSA_METHOD. RSA_meth_set_flags() provides the ability to set
155these flags.
156
157The functions RSA_meth_get0_app_data() and RSA_meth_set0_app_data()
158provide the ability to associate implementation specific data with the
159RSA_METHOD. It is the application's responsibility to free this data
160before the RSA_METHOD is freed via a call to RSA_meth_free().
161
162RSA_meth_get_sign() and RSA_meth_set_sign() get and set the function
163used for creating an RSA signature respectively. This function will be
164called in response to the application calling RSA_sign(). The
165parameters for the function have the same meaning as for RSA_sign().
166
167RSA_meth_get_verify() and RSA_meth_set_verify() get and set the
168function used for verifying an RSA signature respectively. This
169function will be called in response to the application calling
170RSA_verify(). The parameters for the function have the same meaning as
171for RSA_verify().
172
173RSA_meth_get_mod_exp() and RSA_meth_set_mod_exp() get and set the
174function used for CRT computations.
175
176RSA_meth_get_bn_mod_exp() and RSA_meth_set_bn_mod_exp() get and set
177the function used for CRT computations, specifically the following
178value:
179
180 r = a ^ p mod m
181
182Both the mod_exp() and bn_mod_exp() functions are called by the
183default OpenSSL method during encryption, decryption, signing and
184verification.
185
186RSA_meth_get_init() and RSA_meth_set_init() get and set the function
187used for creating a new RSA instance respectively. This function will
188be called in response to the application calling RSA_new() (if the
189current default RSA_METHOD is this one) or RSA_new_method(). The
190RSA_new() and RSA_new_method() functions will allocate the memory for
191the new RSA object, and a pointer to this newly allocated structure
192will be passed as a parameter to the function. This function may be
193NULL.
194
195RSA_meth_get_finish() and RSA_meth_set_finish() get and set the
196function used for destroying an instance of an RSA object respectively.
197This function will be called in response to the application calling
198RSA_free(). A pointer to the RSA to be destroyed is passed as a
199parameter. The destroy function should be used for RSA implementation
200specific clean up. The memory for the RSA itself should not be freed
201by this function. This function may be NULL.
202
203RSA_meth_get_keygen() and RSA_meth_set_keygen() get and set the
204function used for generating a new RSA key pair respectively. This
205function will be called in response to the application calling
206RSA_generate_key_ex(). The parameter for the function has the same
207meaning as for RSA_generate_key_ex().
208
209RSA_meth_get_multi_prime_keygen() and RSA_meth_set_multi_prime_keygen() get
210and set the function used for generating a new multi-prime RSA key pair
211respectively. This function will be called in response to the application calling
212RSA_generate_multi_prime_key(). The parameter for the function has the same
213meaning as for RSA_generate_multi_prime_key().
214
215RSA_meth_get_pub_enc(), RSA_meth_set_pub_enc(),
216RSA_meth_get_pub_dec(), RSA_meth_set_pub_dec(),
217RSA_meth_get_priv_enc(), RSA_meth_set_priv_enc(),
218RSA_meth_get_priv_dec(), RSA_meth_set_priv_dec() get and set the
219functions used for public and private key encryption and decryption.
220These functions will be called in response to the application calling
221RSA_public_encrypt(), RSA_private_decrypt(), RSA_private_encrypt() and
222RSA_public_decrypt() and take the same parameters as those.
223
224
225=head1 RETURN VALUES
226
227RSA_meth_new() and RSA_meth_dup() return the newly allocated
228RSA_METHOD object or NULL on failure.
229
230RSA_meth_get0_name() and RSA_meth_get_flags() return the name and
231flags associated with the RSA_METHOD respectively.
232
233All other RSA_meth_get_*() functions return the appropriate function
234pointer that has been set in the RSA_METHOD, or NULL if no such
235pointer has yet been set.
236
237RSA_meth_set1_name and all RSA_meth_set_*() functions return 1 on
238success or 0 on failure.
239
240=head1 SEE ALSO
241
242L<RSA_new(3)>, L<RSA_generate_key_ex(3)>, L<RSA_sign(3)>,
243L<RSA_set_method(3)>, L<RSA_size(3)>, L<RSA_get0_key(3)>,
244L<RSA_generate_multi_prime_key(3)>
245
246=head1 HISTORY
247
248RSA_meth_get_multi_prime_keygen() and RSA_meth_set_multi_prime_keygen() were
249added in OpenSSL 1.1.1.
250
251Other functions described here were added in OpenSSL 1.1.0.
252
253=head1 COPYRIGHT
254
255Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
256
257Licensed under the OpenSSL license (the "License").  You may not use
258this file except in compliance with the License.  You can obtain a copy
259in the file LICENSE in the source distribution or at
260L<https://www.openssl.org/source/license.html>.
261
262=cut
263