1 /*
2 * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /*
11 * RSA low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <stdio.h>
17 #include <openssl/crypto.h>
18 #include "internal/cryptlib.h"
19 #include "crypto/bn.h"
20 #include <openssl/rand.h>
21 #include "rsa_local.h"
22
RSA_bits(const RSA * r)23 int RSA_bits(const RSA *r)
24 {
25 return BN_num_bits(r->n);
26 }
27
RSA_size(const RSA * r)28 int RSA_size(const RSA *r)
29 {
30 return BN_num_bytes(r->n);
31 }
32
RSA_public_encrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)33 int RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
34 RSA *rsa, int padding)
35 {
36 return rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding);
37 }
38
RSA_private_encrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)39 int RSA_private_encrypt(int flen, const unsigned char *from,
40 unsigned char *to, RSA *rsa, int padding)
41 {
42 return rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding);
43 }
44
RSA_private_decrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)45 int RSA_private_decrypt(int flen, const unsigned char *from,
46 unsigned char *to, RSA *rsa, int padding)
47 {
48 return rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding);
49 }
50
RSA_public_decrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)51 int RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
52 RSA *rsa, int padding)
53 {
54 return rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding);
55 }
56
RSA_flags(const RSA * r)57 int RSA_flags(const RSA *r)
58 {
59 return r == NULL ? 0 : r->meth->flags;
60 }
61
RSA_blinding_off(RSA * rsa)62 void RSA_blinding_off(RSA *rsa)
63 {
64 BN_BLINDING_free(rsa->blinding);
65 rsa->blinding = NULL;
66 rsa->flags &= ~RSA_FLAG_BLINDING;
67 rsa->flags |= RSA_FLAG_NO_BLINDING;
68 }
69
RSA_blinding_on(RSA * rsa,BN_CTX * ctx)70 int RSA_blinding_on(RSA *rsa, BN_CTX *ctx)
71 {
72 int ret = 0;
73
74 if (rsa->blinding != NULL)
75 RSA_blinding_off(rsa);
76
77 rsa->blinding = RSA_setup_blinding(rsa, ctx);
78 if (rsa->blinding == NULL)
79 goto err;
80
81 rsa->flags |= RSA_FLAG_BLINDING;
82 rsa->flags &= ~RSA_FLAG_NO_BLINDING;
83 ret = 1;
84 err:
85 return ret;
86 }
87
rsa_get_public_exp(const BIGNUM * d,const BIGNUM * p,const BIGNUM * q,BN_CTX * ctx)88 static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p,
89 const BIGNUM *q, BN_CTX *ctx)
90 {
91 BIGNUM *ret = NULL, *r0, *r1, *r2;
92
93 if (d == NULL || p == NULL || q == NULL)
94 return NULL;
95
96 BN_CTX_start(ctx);
97 r0 = BN_CTX_get(ctx);
98 r1 = BN_CTX_get(ctx);
99 r2 = BN_CTX_get(ctx);
100 if (r2 == NULL)
101 goto err;
102
103 if (!BN_sub(r1, p, BN_value_one()))
104 goto err;
105 if (!BN_sub(r2, q, BN_value_one()))
106 goto err;
107 if (!BN_mul(r0, r1, r2, ctx))
108 goto err;
109
110 ret = BN_mod_inverse(NULL, d, r0, ctx);
111 err:
112 BN_CTX_end(ctx);
113 return ret;
114 }
115
RSA_setup_blinding(RSA * rsa,BN_CTX * in_ctx)116 BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
117 {
118 BIGNUM *e;
119 BN_CTX *ctx;
120 BN_BLINDING *ret = NULL;
121
122 if (in_ctx == NULL) {
123 if ((ctx = BN_CTX_new_ex(rsa->libctx)) == NULL)
124 return 0;
125 } else {
126 ctx = in_ctx;
127 }
128
129 BN_CTX_start(ctx);
130 e = BN_CTX_get(ctx);
131 if (e == NULL) {
132 ERR_raise(ERR_LIB_RSA, ERR_R_BN_LIB);
133 goto err;
134 }
135
136 if (rsa->e == NULL) {
137 e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
138 if (e == NULL) {
139 ERR_raise(ERR_LIB_RSA, RSA_R_NO_PUBLIC_EXPONENT);
140 goto err;
141 }
142 } else {
143 e = rsa->e;
144 }
145
146 {
147 BIGNUM *n = BN_new();
148
149 if (n == NULL) {
150 ERR_raise(ERR_LIB_RSA, ERR_R_BN_LIB);
151 goto err;
152 }
153 BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME);
154
155 ret = BN_BLINDING_create_param(NULL, e, n, ctx, rsa->meth->bn_mod_exp,
156 rsa->_method_mod_n);
157 /* We MUST free n before any further use of rsa->n */
158 BN_free(n);
159 }
160 if (ret == NULL) {
161 ERR_raise(ERR_LIB_RSA, ERR_R_BN_LIB);
162 goto err;
163 }
164
165 BN_BLINDING_set_current_thread(ret);
166
167 err:
168 BN_CTX_end(ctx);
169 if (ctx != in_ctx)
170 BN_CTX_free(ctx);
171 if (e != rsa->e)
172 BN_free(e);
173
174 return ret;
175 }
176
