xref: /openbsd/lib/libcrypto/bn/bn_local.h (revision 6a951d55)
1 /* $OpenBSD: bn_local.h,v 1.46 2025/01/21 15:44:22 tb Exp $ */
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  * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
60  *
61  * Redistribution and use in source and binary forms, with or without
62  * modification, are permitted provided that the following conditions
63  * are met:
64  *
65  * 1. Redistributions of source code must retain the above copyright
66  *    notice, this list of conditions and the following disclaimer.
67  *
68  * 2. Redistributions in binary form must reproduce the above copyright
69  *    notice, this list of conditions and the following disclaimer in
70  *    the documentation and/or other materials provided with the
71  *    distribution.
72  *
73  * 3. All advertising materials mentioning features or use of this
74  *    software must display the following acknowledgment:
75  *    "This product includes software developed by the OpenSSL Project
76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77  *
78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79  *    endorse or promote products derived from this software without
80  *    prior written permission. For written permission, please contact
81  *    openssl-core@openssl.org.
82  *
83  * 5. Products derived from this software may not be called "OpenSSL"
84  *    nor may "OpenSSL" appear in their names without prior written
85  *    permission of the OpenSSL Project.
86  *
87  * 6. Redistributions of any form whatsoever must retain the following
88  *    acknowledgment:
89  *    "This product includes software developed by the OpenSSL Project
90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91  *
92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103  * OF THE POSSIBILITY OF SUCH DAMAGE.
104  * ====================================================================
105  *
106  * This product includes cryptographic software written by Eric Young
107  * (eay@cryptsoft.com).  This product includes software written by Tim
108  * Hudson (tjh@cryptsoft.com).
109  *
110  */
111 
112 #ifndef HEADER_BN_LOCAL_H
113 #define HEADER_BN_LOCAL_H
114 
115 #include <openssl/opensslconf.h>
116 
117 #include <openssl/bn.h>
118 
119 __BEGIN_HIDDEN_DECLS
120 
121 struct bignum_st {
122 	BN_ULONG *d;	/* Pointer to an array of 'BN_BITS2' bit chunks. */
123 	int top;	/* Index of last used d +1. */
124 	/* The next are internal book keeping for bn_expand. */
125 	int dmax;	/* Size of the d array. */
126 	int neg;	/* one if the number is negative */
127 	int flags;
128 };
129 
130 struct bn_mont_ctx_st {
131 	int ri;		/* Number of bits in R */
132 	BIGNUM RR;	/* Used to convert to Montgomery form */
133 	BIGNUM N;	/* Modulus */
134 
135 	/* Least significant word(s) of Ni; R*(1/R mod N) - N*Ni = 1 */
136 	BN_ULONG n0[2];
137 
138 	int flags;
139 };
140 
141 typedef struct bn_recp_ctx_st BN_RECP_CTX;
142 
143 /* Used for slow "generation" functions. */
144 struct bn_gencb_st {
145 	unsigned int ver;	/* To handle binary (in)compatibility */
146 	void *arg;		/* callback-specific data */
147 	union {
148 		/* if(ver==1) - handles old style callbacks */
149 		void (*cb_1)(int, int, void *);
150 		/* if(ver==2) - new callback style */
151 		int (*cb_2)(int, int, BN_GENCB *);
152 	} cb;
153 };
154 
155 /*
156  * BN_window_bits_for_exponent_size -- macro for sliding window mod_exp functions
157  *
158  *
159  * For window size 'w' (w >= 2) and a random 'b' bits exponent,
160  * the number of multiplications is a constant plus on average
161  *
162  *    2^(w-1) + (b-w)/(w+1);
163  *
164  * here  2^(w-1)  is for precomputing the table (we actually need
165  * entries only for windows that have the lowest bit set), and
166  * (b-w)/(w+1)  is an approximation for the expected number of
167  * w-bit windows, not counting the first one.
168  *
169  * Thus we should use
170  *
171  *    w >= 6  if        b > 671
172  *     w = 5  if  671 > b > 239
173  *     w = 4  if  239 > b >  79
174  *     w = 3  if   79 > b >  23
175  *    w <= 2  if   23 > b
176  *
177  * (with draws in between).  Very small exponents are often selected
178  * with low Hamming weight, so we use  w = 1  for b <= 23.
179  */
180 #define BN_window_bits_for_exponent_size(b) \
181 		((b) > 671 ? 6 : \
182 		 (b) > 239 ? 5 : \
183 		 (b) >  79 ? 4 : \
184 		 (b) >  23 ? 3 : 1)
185 
186 
187 /* BN_mod_exp_mont_consttime is based on the assumption that the
188  * L1 data cache line width of the target processor is at least
189  * the following value.
190  */
191 #define MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH	( 64 )
192 #define MOD_EXP_CTIME_MIN_CACHE_LINE_MASK	(MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH - 1)
193 
194 /* Window sizes optimized for fixed window size modular exponentiation
195  * algorithm (BN_mod_exp_mont_consttime).
196  *
197  * To achieve the security goals of BN_mode_exp_mont_consttime, the
198  * maximum size of the window must not exceed
199  * log_2(MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH).
200  *
201  * Window size thresholds are defined for cache line sizes of 32 and 64,
202  * cache line sizes where log_2(32)=5 and log_2(64)=6 respectively. A
203  * window size of 7 should only be used on processors that have a 128
204  * byte or greater cache line size.
205  */
206 #if MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 64
207 
208 #  define BN_window_bits_for_ctime_exponent_size(b) \
209 		((b) > 937 ? 6 : \
210 		 (b) > 306 ? 5 : \
211 		 (b) >  89 ? 4 : \
212 		 (b) >  22 ? 3 : 1)
213 #  define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE	(6)
214 
215 #elif MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 32
216 
217 #  define BN_window_bits_for_ctime_exponent_size(b) \
218 		((b) > 306 ? 5 : \
219 		 (b) >  89 ? 4 : \
220 		 (b) >  22 ? 3 : 1)
221 #  define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE	(5)
222 
223 #endif
224 
225 
226 /* Pentium pro 16,16,16,32,64 */
227 /* Alpha       16,16,16,16.64 */
228 #define BN_MULL_SIZE_NORMAL			(16) /* 32 */
229 #define BN_MUL_RECURSIVE_SIZE_NORMAL		(16) /* 32 less than */
230 #define BN_SQR_RECURSIVE_SIZE_NORMAL		(16) /* 32 */
231 #define BN_MUL_LOW_RECURSIVE_SIZE_NORMAL	(32) /* 32 */
232 #define BN_MONT_CTX_SET_SIZE_WORD		(64) /* 32 */
233 
234 /* The least significant word of a BIGNUM. */
235 #define BN_lsw(n) (((n)->top == 0) ? (BN_ULONG) 0 : (n)->d[0])
236 
237 BN_ULONG bn_add(BN_ULONG *r, int r_len, const BN_ULONG *a, int a_len,
238     const BN_ULONG *b, int b_len);
239 BN_ULONG bn_sub(BN_ULONG *r, int r_len, const BN_ULONG *a, int a_len,
240     const BN_ULONG *b, int b_len);
241 
242 void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb);
243 void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b);
244 void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b);
245 
246 void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a);
247 void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a);
248 
249 int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
250     const BN_ULONG *np, const BN_ULONG *n0, int num);
251 
252 void bn_correct_top(BIGNUM *a);
253 int bn_expand_bits(BIGNUM *a, size_t bits);
254 int bn_expand_bytes(BIGNUM *a, size_t bytes);
255 int bn_wexpand(BIGNUM *a, int words);
256 
257 BN_ULONG bn_add_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
258     int num);
259 BN_ULONG bn_sub_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
260     int num);
261 BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w);
262 BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w);
263 void     bn_sqr_words(BN_ULONG *rp, const BN_ULONG *ap, int num);
264 BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d);
265 void bn_div_rem_words(BN_ULONG h, BN_ULONG l, BN_ULONG d, BN_ULONG *out_q,
266     BN_ULONG *out_r);
267 
268 int BN_bntest_rand(BIGNUM *rnd, int bits, int top, int bottom);
269 int bn_rand_in_range(BIGNUM *rnd, const BIGNUM *lower_inc, const BIGNUM *upper_exc);
270 int bn_rand_interval(BIGNUM *rnd, BN_ULONG lower_word, const BIGNUM *upper_exc);
271 
272 void	BN_init(BIGNUM *);
273 
274 BN_RECP_CTX *BN_RECP_CTX_create(const BIGNUM *N);
275 void BN_RECP_CTX_free(BN_RECP_CTX *recp);
276 int	BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, BN_RECP_CTX *recp,
277     BN_CTX *ctx);
278 int	BN_mod_mul_reciprocal(BIGNUM *r, const BIGNUM *x, const BIGNUM *y,
279     BN_RECP_CTX *recp, BN_CTX *ctx);
280 int	BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
281     const BIGNUM *m, BN_CTX *ctx);
282 
283 /* Explicitly const time / non-const time versions for internal use */
284 int BN_mod_exp_ct(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
285     const BIGNUM *m, BN_CTX *ctx);
286 int BN_mod_exp_nonct(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
287     const BIGNUM *m, BN_CTX *ctx);
288 int BN_mod_exp_mont_ct(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
289     const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
290 int BN_mod_exp_mont_nonct(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
291     const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
292 int BN_div_nonct(BIGNUM *q, BIGNUM *r, const BIGNUM *n, const BIGNUM *d,
293     BN_CTX *ctx);
294 int BN_div_ct(BIGNUM *q, BIGNUM *r, const BIGNUM *n, const BIGNUM *d,
295     BN_CTX *ctx);
296 int BN_mod_ct(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx);
297 int BN_mod_nonct(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx);
298 
299 int BN_mod_exp_mont_word(BIGNUM *r, BN_ULONG a, const BIGNUM *p,
300     const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
301 int BN_mod_exp2_mont(BIGNUM *r, const BIGNUM *a1, const BIGNUM *p1,
302     const BIGNUM *a2, const BIGNUM *p2, const BIGNUM *m,
303     BN_CTX *ctx, BN_MONT_CTX *m_ctx);
304 
305 int BN_mod_exp_simple(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
306     const BIGNUM *m, BN_CTX *ctx);
307 
308 BIGNUM *BN_mod_inverse_ct(BIGNUM *ret, const BIGNUM *a, const BIGNUM *n,
309     BN_CTX *ctx);
310 BIGNUM *BN_mod_inverse_nonct(BIGNUM *ret, const BIGNUM *a, const BIGNUM *n,
311     BN_CTX *ctx);
312 int	BN_gcd_ct(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx);
313 
314 int	BN_swap_ct(BN_ULONG swap, BIGNUM *a, BIGNUM *b, size_t nwords);
315 
316 int bn_copy(BIGNUM *dst, const BIGNUM *src);
317 
318 int bn_isqrt(BIGNUM *out_sqrt, int *out_perfect, const BIGNUM *n, BN_CTX *ctx);
319 int bn_is_perfect_square(int *out_perfect, const BIGNUM *n, BN_CTX *ctx);
320 
321 int bn_is_prime_bpsw(int *is_prime, const BIGNUM *n, BN_CTX *ctx, size_t rounds);
322 
323 int bn_printf(BIO *bio, const BIGNUM *bn, int indent, const char *fmt, ...)
324     __attribute__((__format__ (printf, 4, 5)))
325     __attribute__((__nonnull__ (4)));
326 
327 int bn_bn2hex_nosign(const BIGNUM *bn, char **out, size_t *out_len);
328 int bn_bn2hex_nibbles(const BIGNUM *bn, char **out, size_t *out_len);
329 
330 __END_HIDDEN_DECLS
331 #endif /* !HEADER_BN_LOCAL_H */
332