1RSA_SET_METHOD(3ossl) OpenSSL RSA_SET_METHOD(3ossl)
2
6 RSA_set_default_method, RSA_get_default_method, RSA_set_method,
7 RSA_get_method, RSA_PKCS1_OpenSSL, RSA_flags, RSA_new_method - select
8 RSA method
9
11 #include <openssl/rsa.h>
12 The following functions have been deprecated since OpenSSL 3.0, and can
14 be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
15 version value, see openssl_user_macros(7):
16 void RSA_set_default_method(const RSA_METHOD *meth);
18 const RSA_METHOD *RSA_get_default_method(void);
20 int RSA_set_method(RSA *rsa, const RSA_METHOD *meth);
22 const RSA_METHOD *RSA_get_method(const RSA *rsa);
24 const RSA_METHOD *RSA_PKCS1_OpenSSL(void);
26 int RSA_flags(const RSA *rsa);
28 RSA *RSA_new_method(ENGINE *engine);
30
32 All of the functions described on this page are deprecated.
33 Applications should instead use the OSSL_PROVIDER APIs.
34 An RSA_METHOD specifies the functions that OpenSSL uses for RSA
36 operations. By modifying the method, alternative implementations such
37 as hardware accelerators may be used. IMPORTANT: See the NOTES section
38 for important information about how these RSA API functions are
39 affected by the use of ENGINE API calls.
40 Initially, the default RSA_METHOD is the OpenSSL internal
42 implementation, as returned by RSA_PKCS1_OpenSSL().
43 RSA_set_default_method() makes meth the default method for all RSA
45 structures created later. NB: This is true only whilst no ENGINE has
46 been set as a default for RSA, so this function is no longer
47 recommended. This function is not thread-safe and should not be called
48 at the same time as other OpenSSL functions.
49 RSA_get_default_method() returns a pointer to the current default
51 RSA_METHOD. However, the meaningfulness of this result is dependent on
52 whether the ENGINE API is being used, so this function is no longer
53 recommended.
54 RSA_set_method() selects meth to perform all operations using the key
56 rsa. This will replace the RSA_METHOD used by the RSA key and if the
57 previous method was supplied by an ENGINE, the handle to that ENGINE
58 will be released during the change. It is possible to have RSA keys
59 that only work with certain RSA_METHOD implementations (e.g. from an
60 ENGINE module that supports embedded hardware-protected keys), and in
61 such cases attempting to change the RSA_METHOD for the key can have
62 unexpected results.
63 RSA_get_method() returns a pointer to the RSA_METHOD being used by rsa.
65 This method may or may not be supplied by an ENGINE implementation, but
66 if it is, the return value can only be guaranteed to be valid as long
67 as the RSA key itself is valid and does not have its implementation
68 changed by RSA_set_method().
69 RSA_flags() returns the flags that are set for rsa's current
71 RSA_METHOD. See the BUGS section.
72 RSA_new_method() allocates and initializes an RSA structure so that
74 engine will be used for the RSA operations. If engine is NULL, the
75 default ENGINE for RSA operations is used, and if no default ENGINE is
76 set, the RSA_METHOD controlled by RSA_set_default_method() is used.
77 RSA_flags() returns the flags that are set for rsa's current method.
79 RSA_new_method() allocates and initializes an RSA structure so that
81 method will be used for the RSA operations. If method is NULL, the
82 default method is used.
83
85 typedef struct rsa_meth_st
86 {
87 /* name of the implementation */
88 const char *name;
89 /* encrypt */
91 int (*rsa_pub_enc)(int flen, unsigned char *from,
92 unsigned char *to, RSA *rsa, int padding);
93 /* verify arbitrary data */
95 int (*rsa_pub_dec)(int flen, unsigned char *from,
96 unsigned char *to, RSA *rsa, int padding);
97 /* sign arbitrary data */
99 int (*rsa_priv_enc)(int flen, unsigned char *from,
100 unsigned char *to, RSA *rsa, int padding);
101 /* decrypt */
103 int (*rsa_priv_dec)(int flen, unsigned char *from,
104 unsigned char *to, RSA *rsa, int padding);
105 /* compute r0 = r0 ^ I mod rsa->n (May be NULL for some implementations) */
107 int (*rsa_mod_exp)(BIGNUM *r0, BIGNUM *I, RSA *rsa);
108 /* compute r = a ^ p mod m (May be NULL for some implementations) */
110 int (*bn_mod_exp)(BIGNUM *r, BIGNUM *a, const BIGNUM *p,
111 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
112 /* called at RSA_new */
114 int (*init)(RSA *rsa);
115 /* called at RSA_free */
117 int (*finish)(RSA *rsa);
118 /*
120 * RSA_FLAG_EXT_PKEY - rsa_mod_exp is called for private key
121 * operations, even if p,q,dmp1,dmq1,iqmp
122 * are NULL
123 * RSA_METHOD_FLAG_NO_CHECK - don't check pub/private match
124 */
125 int flags;
126 char *app_data; /* ?? */
128 int (*rsa_sign)(int type,
130 const unsigned char *m, unsigned int m_length,
131 unsigned char *sigret, unsigned int *siglen, const RSA *rsa);
132 int (*rsa_verify)(int dtype,
133 const unsigned char *m, unsigned int m_length,
134 const unsigned char *sigbuf, unsigned int siglen,
135 const RSA *rsa);
136 /* keygen. If NULL built-in RSA key generation will be used */
137 int (*rsa_keygen)(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb);
138 } RSA_METHOD;
140
142 RSA_PKCS1_OpenSSL(), RSA_PKCS1_null_method(), RSA_get_default_method()
143 and RSA_get_method() return pointers to the respective RSA_METHODs.
144 RSA_set_default_method() returns no value.
146 RSA_set_method() returns a pointer to the old RSA_METHOD implementation
148 that was replaced. However, this return value should probably be
149 ignored because if it was supplied by an ENGINE, the pointer could be
150 invalidated at any time if the ENGINE is unloaded (in fact it could be
151 unloaded as a result of the RSA_set_method() function releasing its
152 handle to the ENGINE). For this reason, the return type may be replaced
153 with a void declaration in a future release.
154 RSA_new_method() returns NULL and sets an error code that can be
156 obtained by ERR_get_error(3) if the allocation fails. Otherwise it
157 returns a pointer to the newly allocated structure.
158
160 The behaviour of RSA_flags() is a mis-feature that is left as-is for
161 now to avoid creating compatibility problems. RSA functionality, such
162 as the encryption functions, are controlled by the flags value in the
163 RSA key itself, not by the flags value in the RSA_METHOD attached to
164 the RSA key (which is what this function returns). If the flags element
165 of an RSA key is changed, the changes will be honoured by RSA
166 functionality but will not be reflected in the return value of the
167 RSA_flags() function - in effect RSA_flags() behaves more like an
168 RSA_default_flags() function (which does not currently exist).
169
171 RSA_new(3)
172
174 All of these functions were deprecated in OpenSSL 3.0.
175 The RSA_null_method(), which was a partial attempt to avoid patent
177 issues, was replaced to always return NULL in OpenSSL 1.1.1.
178
180 Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
181 Licensed under the Apache License 2.0 (the "License"). You may not use
183 this file except in compliance with the License. You can obtain a copy
184 in the file LICENSE in the source distribution or at
185 <https://www.openssl.org/source/license.html>.
1863.1.1 2023-08-31 RSA_SET_METHOD(3ossl)