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Diffstat (limited to 'src/lib/libcrypto/dh/dh_key.c')
-rw-r--r-- | src/lib/libcrypto/dh/dh_key.c | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/src/lib/libcrypto/dh/dh_key.c b/src/lib/libcrypto/dh/dh_key.c new file mode 100644 index 0000000000..e7db440342 --- /dev/null +++ b/src/lib/libcrypto/dh/dh_key.c | |||
@@ -0,0 +1,263 @@ | |||
1 | /* crypto/dh/dh_key.c */ | ||
2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) | ||
3 | * All rights reserved. | ||
4 | * | ||
5 | * This package is an SSL implementation written | ||
6 | * by Eric Young (eay@cryptsoft.com). | ||
7 | * The implementation was written so as to conform with Netscapes SSL. | ||
8 | * | ||
9 | * This library is free for commercial and non-commercial use as long as | ||
10 | * the following conditions are aheared to. The following conditions | ||
11 | * apply to all code found in this distribution, be it the RC4, RSA, | ||
12 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation | ||
13 | * included with this distribution is covered by the same copyright terms | ||
14 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). | ||
15 | * | ||
16 | * Copyright remains Eric Young's, and as such any Copyright notices in | ||
17 | * the code are not to be removed. | ||
18 | * If this package is used in a product, Eric Young should be given attribution | ||
19 | * as the author of the parts of the library used. | ||
20 | * This can be in the form of a textual message at program startup or | ||
21 | * in documentation (online or textual) provided with the package. | ||
22 | * | ||
23 | * Redistribution and use in source and binary forms, with or without | ||
24 | * modification, are permitted provided that the following conditions | ||
25 | * are met: | ||
26 | * 1. Redistributions of source code must retain the copyright | ||
27 | * notice, this list of conditions and the following disclaimer. | ||
28 | * 2. Redistributions in binary form must reproduce the above copyright | ||
29 | * notice, this list of conditions and the following disclaimer in the | ||
30 | * documentation and/or other materials provided with the distribution. | ||
31 | * 3. All advertising materials mentioning features or use of this software | ||
32 | * must display the following acknowledgement: | ||
33 | * "This product includes cryptographic software written by | ||
34 | * Eric Young (eay@cryptsoft.com)" | ||
35 | * The word 'cryptographic' can be left out if the rouines from the library | ||
36 | * being used are not cryptographic related :-). | ||
37 | * 4. If you include any Windows specific code (or a derivative thereof) from | ||
38 | * the apps directory (application code) you must include an acknowledgement: | ||
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | ||
40 | * | ||
41 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND | ||
42 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
43 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
44 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | ||
45 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
46 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
47 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
49 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
50 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
51 | * SUCH DAMAGE. | ||
52 | * | ||
53 | * The licence and distribution terms for any publically available version or | ||
54 | * derivative of this code cannot be changed. i.e. this code cannot simply be | ||
55 | * copied and put under another distribution licence | ||
56 | * [including the GNU Public Licence.] | ||
57 | */ | ||
58 | |||
59 | #include <stdio.h> | ||
60 | #include "cryptlib.h" | ||
61 | #include <openssl/bn.h> | ||
62 | #include <openssl/rand.h> | ||
63 | #include <openssl/dh.h> | ||
64 | |||
65 | static int generate_key(DH *dh); | ||
66 | static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh); | ||
67 | static int dh_bn_mod_exp(const DH *dh, BIGNUM *r, | ||
68 | const BIGNUM *a, const BIGNUM *p, | ||
69 | const BIGNUM *m, BN_CTX *ctx, | ||
70 | BN_MONT_CTX *m_ctx); | ||
71 | static int dh_init(DH *dh); | ||
72 | static int dh_finish(DH *dh); | ||
73 | |||
74 | int DH_generate_key(DH *dh) | ||
75 | { | ||
76 | return dh->meth->generate_key(dh); | ||
77 | } | ||
78 | |||
79 | int DH_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) | ||
80 | { | ||
81 | return dh->meth->compute_key(key, pub_key, dh); | ||
82 | } | ||
83 | |||
84 | static DH_METHOD dh_ossl = { | ||
85 | "OpenSSL DH Method", | ||
86 | generate_key, | ||
87 | compute_key, | ||
88 | dh_bn_mod_exp, | ||
89 | dh_init, | ||
90 | dh_finish, | ||
91 | 0, | ||
92 | NULL, | ||
93 | NULL | ||
94 | }; | ||
95 | |||
96 | const DH_METHOD *DH_OpenSSL(void) | ||
97 | { | ||
98 | return &dh_ossl; | ||
99 | } | ||
100 | |||
101 | static int generate_key(DH *dh) | ||
102 | { | ||
103 | int ok=0; | ||
104 | int generate_new_key=0; | ||
105 | unsigned l; | ||
106 | BN_CTX *ctx; | ||
107 | BN_MONT_CTX *mont=NULL; | ||
108 | BIGNUM *pub_key=NULL,*priv_key=NULL; | ||
109 | |||
110 | ctx = BN_CTX_new(); | ||
111 | if (ctx == NULL) goto err; | ||
112 | |||
113 | if (dh->priv_key == NULL) | ||
114 | { | ||
115 | priv_key=BN_new(); | ||
116 | if (priv_key == NULL) goto err; | ||
117 | generate_new_key=1; | ||
118 | } | ||
119 | else | ||
120 | priv_key=dh->priv_key; | ||
121 | |||
122 | if (dh->pub_key == NULL) | ||
123 | { | ||
124 | pub_key=BN_new(); | ||
125 | if (pub_key == NULL) goto err; | ||
126 | } | ||
127 | else | ||
128 | pub_key=dh->pub_key; | ||
129 | |||
130 | |||
131 | if (dh->flags & DH_FLAG_CACHE_MONT_P) | ||
132 | { | ||
133 | mont = BN_MONT_CTX_set_locked(&dh->method_mont_p, | ||
134 | CRYPTO_LOCK_DH, dh->p, ctx); | ||
135 | if (!mont) | ||
136 | goto err; | ||
137 | } | ||
138 | |||
139 | if (generate_new_key) | ||
140 | { | ||
141 | l = dh->length ? dh->length : BN_num_bits(dh->p)-1; /* secret exponent length */ | ||
142 | if (!BN_rand(priv_key, l, 0, 0)) goto err; | ||
143 | } | ||
144 | |||
145 | { | ||
146 | BIGNUM local_prk; | ||
147 | BIGNUM *prk; | ||
148 | |||
149 | if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) | ||
150 | { | ||
151 | BN_init(&local_prk); | ||
152 | prk = &local_prk; | ||
153 | BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME); | ||
154 | } | ||
155 | else | ||
156 | prk = priv_key; | ||
157 | |||
158 | if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, prk, dh->p, ctx, mont)) goto err; | ||
159 | } | ||
160 | |||
161 | dh->pub_key=pub_key; | ||
162 | dh->priv_key=priv_key; | ||
163 | ok=1; | ||
164 | err: | ||
165 | if (ok != 1) | ||
166 | DHerr(DH_F_GENERATE_KEY,ERR_R_BN_LIB); | ||
167 | |||
168 | if ((pub_key != NULL) && (dh->pub_key == NULL)) BN_free(pub_key); | ||
169 | if ((priv_key != NULL) && (dh->priv_key == NULL)) BN_free(priv_key); | ||
170 | BN_CTX_free(ctx); | ||
171 | return(ok); | ||
172 | } | ||
173 | |||
174 | static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) | ||
175 | { | ||
176 | BN_CTX *ctx=NULL; | ||
177 | BN_MONT_CTX *mont=NULL; | ||
178 | BIGNUM *tmp; | ||
179 | int ret= -1; | ||
180 | int check_result; | ||
181 | |||
182 | if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) | ||
183 | { | ||
184 | DHerr(DH_F_COMPUTE_KEY,DH_R_MODULUS_TOO_LARGE); | ||
185 | goto err; | ||
186 | } | ||
187 | |||
188 | ctx = BN_CTX_new(); | ||
189 | if (ctx == NULL) goto err; | ||
190 | BN_CTX_start(ctx); | ||
191 | tmp = BN_CTX_get(ctx); | ||
192 | |||
193 | if (dh->priv_key == NULL) | ||
194 | { | ||
195 | DHerr(DH_F_COMPUTE_KEY,DH_R_NO_PRIVATE_VALUE); | ||
196 | goto err; | ||
197 | } | ||
198 | |||
199 | if (dh->flags & DH_FLAG_CACHE_MONT_P) | ||
200 | { | ||
201 | mont = BN_MONT_CTX_set_locked(&dh->method_mont_p, | ||
202 | CRYPTO_LOCK_DH, dh->p, ctx); | ||
203 | if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) | ||
204 | { | ||
205 | /* XXX */ | ||
206 | BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME); | ||
207 | } | ||
208 | if (!mont) | ||
209 | goto err; | ||
210 | } | ||
211 | |||
212 | if (!DH_check_pub_key(dh, pub_key, &check_result) || check_result) | ||
213 | { | ||
214 | DHerr(DH_F_COMPUTE_KEY,DH_R_INVALID_PUBKEY); | ||
215 | goto err; | ||
216 | } | ||
217 | |||
218 | if (!dh->meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key,dh->p,ctx,mont)) | ||
219 | { | ||
220 | DHerr(DH_F_COMPUTE_KEY,ERR_R_BN_LIB); | ||
221 | goto err; | ||
222 | } | ||
223 | |||
224 | ret=BN_bn2bin(tmp,key); | ||
225 | err: | ||
226 | if (ctx != NULL) | ||
227 | { | ||
228 | BN_CTX_end(ctx); | ||
229 | BN_CTX_free(ctx); | ||
230 | } | ||
231 | return(ret); | ||
232 | } | ||
233 | |||
234 | static int dh_bn_mod_exp(const DH *dh, BIGNUM *r, | ||
235 | const BIGNUM *a, const BIGNUM *p, | ||
236 | const BIGNUM *m, BN_CTX *ctx, | ||
237 | BN_MONT_CTX *m_ctx) | ||
238 | { | ||
239 | /* If a is only one word long and constant time is false, use the faster | ||
240 | * exponenentiation function. | ||
241 | */ | ||
242 | if (a->top == 1 && ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) != 0)) | ||
243 | { | ||
244 | BN_ULONG A = a->d[0]; | ||
245 | return BN_mod_exp_mont_word(r,A,p,m,ctx,m_ctx); | ||
246 | } | ||
247 | else | ||
248 | return BN_mod_exp_mont(r,a,p,m,ctx,m_ctx); | ||
249 | } | ||
250 | |||
251 | |||
252 | static int dh_init(DH *dh) | ||
253 | { | ||
254 | dh->flags |= DH_FLAG_CACHE_MONT_P; | ||
255 | return(1); | ||
256 | } | ||
257 | |||
258 | static int dh_finish(DH *dh) | ||
259 | { | ||
260 | if(dh->method_mont_p) | ||
261 | BN_MONT_CTX_free(dh->method_mont_p); | ||
262 | return(1); | ||
263 | } | ||