xref: /freebsd/crypto/openssl/crypto/bn/bn_local.h (revision f25b8c9fb4f58cf61adb47d7570abe7caa6d385d)
1 /*
2  * Copyright 1995-2023 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 #ifndef OSSL_CRYPTO_BN_LOCAL_H
11 #define OSSL_CRYPTO_BN_LOCAL_H
12 
13 /*
14  * The EDK2 build doesn't use bn_conf.h; it sets THIRTY_TWO_BIT or
15  * SIXTY_FOUR_BIT in its own environment since it doesn't re-run our
16  * Configure script and needs to support both 32-bit and 64-bit.
17  */
18 #include <openssl/opensslconf.h>
19 
20 #if !defined(OPENSSL_SYS_UEFI)
21 #include "crypto/bn_conf.h"
22 #endif
23 
24 #include "crypto/bn.h"
25 #include "internal/cryptlib.h"
26 #include "internal/numbers.h"
27 
28 /*
29  * These preprocessor symbols control various aspects of the bignum headers
30  * and library code. They're not defined by any "normal" configuration, as
31  * they are intended for development and testing purposes. NB: defining
32  * them can be useful for debugging application code as well as openssl
33  * itself. BN_DEBUG - turn on various debugging alterations to the bignum
34  * code BN_RAND_DEBUG - uses random poisoning of unused words to trip up
35  * mismanagement of bignum internals. Enable BN_RAND_DEBUG is known to
36  * break some of the OpenSSL tests.
37  */
38 #if defined(BN_RAND_DEBUG) && !defined(BN_DEBUG)
39 #define BN_DEBUG
40 #endif
41 #if defined(BN_RAND_DEBUG)
42 #include <openssl/rand.h>
43 #endif
44 
45 /*
46  * This should limit the stack usage due to alloca to about 4K.
47  * BN_SOFT_LIMIT is a soft limit equivalent to 2*OPENSSL_RSA_MAX_MODULUS_BITS.
48  * Beyond that size bn_mul_mont is no longer used, and the constant time
49  * assembler code is disabled, due to the blatant alloca and bn_mul_mont usage.
50  * Note that bn_mul_mont does an alloca that is hidden away in assembly.
51  * It is not recommended to do computations with numbers exceeding this limit,
52  * since the result will be highly version dependent:
53  * While the current OpenSSL version will use non-optimized, but safe code,
54  * previous versions will use optimized code, that may crash due to unexpected
55  * stack overflow, and future versions may very well turn this into a hard
56  * limit.
57  * Note however, that it is possible to override the size limit using
58  * "./config -DBN_SOFT_LIMIT=<limit>" if necessary, and the O/S specific
59  * stack limit is known and taken into consideration.
60  */
61 #ifndef BN_SOFT_LIMIT
62 #define BN_SOFT_LIMIT (4096 / BN_BYTES)
63 #endif
64 
65 #ifndef OPENSSL_SMALL_FOOTPRINT
66 #define BN_MUL_COMBA
67 #define BN_SQR_COMBA
68 #define BN_RECURSION
69 #endif
70 
71 /*
72  * This next option uses the C libraries (2 word)/(1 word) function. If it is
73  * not defined, I use my C version (which is slower). The reason for this
74  * flag is that when the particular C compiler library routine is used, and
75  * the library is linked with a different compiler, the library is missing.
76  * This mostly happens when the library is built with gcc and then linked
77  * using normal cc.  This would be a common occurrence because gcc normally
78  * produces code that is 2 times faster than system compilers for the big
79  * number stuff. For machines with only one compiler (or shared libraries),
80  * this should be on.  Again this in only really a problem on machines using
81  * "long long's", are 32bit, and are not using my assembler code.
82  */
83 #if defined(OPENSSL_SYS_MSDOS) || defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32) || defined(linux)
84 #define BN_DIV2W
85 #endif
86 
87 /*
88  * 64-bit processor with LP64 ABI
89  */
90 #ifdef SIXTY_FOUR_BIT_LONG
91 #define BN_ULLONG unsigned long long
92 #define BN_BITS4 32
93 #define BN_MASK2 (0xffffffffffffffffL)
94 #define BN_MASK2l (0xffffffffL)
95 #define BN_MASK2h (0xffffffff00000000L)
96 #define BN_MASK2h1 (0xffffffff80000000L)
97 #define BN_DEC_CONV (10000000000000000000UL)
98 #define BN_DEC_NUM 19
99 #define BN_DEC_FMT1 "%lu"
100 #define BN_DEC_FMT2 "%019lu"
101 #endif
102 
103 /*
104  * 64-bit processor other than LP64 ABI
105  */
106 #ifdef SIXTY_FOUR_BIT
107 #undef BN_LLONG
108 #undef BN_ULLONG
109 #define BN_BITS4 32
110 #define BN_MASK2 (0xffffffffffffffffLL)
111 #define BN_MASK2l (0xffffffffL)
112 #define BN_MASK2h (0xffffffff00000000LL)
113 #define BN_MASK2h1 (0xffffffff80000000LL)
114 #define BN_DEC_CONV (10000000000000000000ULL)
115 #define BN_DEC_NUM 19
116 #define BN_DEC_FMT1 "%llu"
117 #define BN_DEC_FMT2 "%019llu"
118 #endif
119 
120 #ifdef THIRTY_TWO_BIT
121 #ifdef BN_LLONG
122 #if defined(_WIN32) && !defined(__GNUC__)
123 #define BN_ULLONG unsigned __int64
124 #else
125 #define BN_ULLONG unsigned long long
126 #endif
127 #endif
128 #define BN_BITS4 16
129 #define BN_MASK2 (0xffffffffL)
130 #define BN_MASK2l (0xffff)
131 #define BN_MASK2h1 (0xffff8000L)
132 #define BN_MASK2h (0xffff0000L)
133 #define BN_DEC_CONV (1000000000L)
134 #define BN_DEC_NUM 9
135 #define BN_DEC_FMT1 "%u"
136 #define BN_DEC_FMT2 "%09u"
137 #endif
138 
139 /*-
140  * Bignum consistency macros
141  * There is one "API" macro, bn_fix_top(), for stripping leading zeroes from
142  * bignum data after direct manipulations on the data. There is also an
143  * "internal" macro, bn_check_top(), for verifying that there are no leading
144  * zeroes. Unfortunately, some auditing is required due to the fact that
145  * bn_fix_top() has become an overabused duct-tape because bignum data is
146  * occasionally passed around in an inconsistent state. So the following
147  * changes have been made to sort this out;
148  * - bn_fix_top()s implementation has been moved to bn_correct_top()
149  * - if BN_DEBUG isn't defined, bn_fix_top() maps to bn_correct_top(), and
150  *   bn_check_top() is as before.
151  * - if BN_DEBUG *is* defined;
152  *   - bn_check_top() tries to pollute unused words even if the bignum 'top' is
153  *     consistent. (ed: only if BN_RAND_DEBUG is defined)
154  *   - bn_fix_top() maps to bn_check_top() rather than "fixing" anything.
155  * The idea is to have debug builds flag up inconsistent bignums when they
156  * occur. If that occurs in a bn_fix_top(), we examine the code in question; if
157  * the use of bn_fix_top() was appropriate (ie. it follows directly after code
158  * that manipulates the bignum) it is converted to bn_correct_top(), and if it
159  * was not appropriate, we convert it permanently to bn_check_top() and track
160  * down the cause of the bug. Eventually, no internal code should be using the
161  * bn_fix_top() macro. External applications and libraries should try this with
162  * their own code too, both in terms of building against the openssl headers
163  * with BN_DEBUG defined *and* linking with a version of OpenSSL built with it
164  * defined. This not only improves external code, it provides more test
165  * coverage for openssl's own code.
166  */
167 
168 #ifdef BN_DEBUG
169 /*
170  * The new BN_FLG_FIXED_TOP flag marks vectors that were not treated with
171  * bn_correct_top, in other words such vectors are permitted to have zeros
172  * in most significant limbs. Such vectors are used internally to achieve
173  * execution time invariance for critical operations with private keys.
174  * It's BN_DEBUG-only flag, because user application is not supposed to
175  * observe it anyway. Moreover, optimizing compiler would actually remove
176  * all operations manipulating the bit in question in non-BN_DEBUG build.
177  */
178 #define BN_FLG_FIXED_TOP 0x10000
179 #ifdef BN_RAND_DEBUG
180 #define bn_pollute(a)                                                                       \
181     do {                                                                                    \
182         const BIGNUM *_bnum1 = (a);                                                         \
183         if (_bnum1->top < _bnum1->dmax) {                                                   \
184             unsigned char _tmp_char;                                                        \
185             /* We cast away const without the compiler knowing, any                         \
186              * *genuinely* constant variables that aren't mutable                           \
187              * wouldn't be constructed with top!=dmax. */                                   \
188             BN_ULONG *_not_const;                                                           \
189             memcpy(&_not_const, &_bnum1->d, sizeof(_not_const));                            \
190             (void)RAND_bytes(&_tmp_char, 1); /* Debug only - safe to ignore error return */ \
191             memset(_not_const + _bnum1->top, _tmp_char,                                     \
192                 sizeof(*_not_const) * (_bnum1->dmax - _bnum1->top));                        \
193         }                                                                                   \
194     } while (0)
195 #else
196 #define bn_pollute(a)
197 #endif
198 #define bn_check_top(a)                                                                                                                   \
199     do {                                                                                                                                  \
200         const BIGNUM *_bnum2 = (a);                                                                                                       \
201         if (_bnum2 != NULL) {                                                                                                             \
202             int _top = _bnum2->top;                                                                                                       \
203             (void)ossl_assert((_top == 0 && !_bnum2->neg) || (_top && ((_bnum2->flags & BN_FLG_FIXED_TOP) || _bnum2->d[_top - 1] != 0))); \
204             bn_pollute(_bnum2);                                                                                                           \
205         }                                                                                                                                 \
206     } while (0)
207 
208 #define bn_fix_top(a) bn_check_top(a)
209 
210 #define bn_check_size(bn, bits) bn_wcheck_size(bn, ((bits + BN_BITS2 - 1)) / BN_BITS2)
211 #define bn_wcheck_size(bn, words)                                      \
212     do {                                                               \
213         const BIGNUM *_bnum2 = (bn);                                   \
214         assert((words) <= (_bnum2)->dmax && (words) >= (_bnum2)->top); \
215         /* avoid unused variable warning with NDEBUG */                \
216         (void)(_bnum2);                                                \
217     } while (0)
218 
219 #else /* !BN_DEBUG */
220 
221 #define BN_FLG_FIXED_TOP 0
222 #define bn_pollute(a)
223 #define bn_check_top(a)
224 #define bn_fix_top(a) bn_correct_top(a)
225 #define bn_check_size(bn, bits)
226 #define bn_wcheck_size(bn, words)
227 
228 #endif
229 
230 BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num,
231     BN_ULONG w);
232 BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w);
233 void bn_sqr_words(BN_ULONG *rp, const BN_ULONG *ap, int num);
234 BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d);
235 BN_ULONG bn_add_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
236     int num);
237 BN_ULONG bn_sub_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
238     int num);
239 
240 struct bignum_st {
241     BN_ULONG *d; /*
242                   * Pointer to an array of 'BN_BITS2' bit
243                   * chunks. These chunks are organised in
244                   * a least significant chunk first order.
245                   */
246     int top; /* Index of last used d +1. */
247     /* The next are internal book keeping for bn_expand. */
248     int dmax; /* Size of the d array. */
249     int neg; /* one if the number is negative */
250     int flags;
251 };
252 
253 /* Used for montgomery multiplication */
254 struct bn_mont_ctx_st {
255     int ri; /* number of bits in R */
256     BIGNUM RR; /* used to convert to montgomery form,
257                   possibly zero-padded */
258     BIGNUM N; /* The modulus */
259     BIGNUM Ni; /* R*(1/R mod N) - N*Ni = 1 (Ni is only
260                 * stored for bignum algorithm) */
261     BN_ULONG n0[2]; /* least significant word(s) of Ni; (type
262                      * changed with 0.9.9, was "BN_ULONG n0;"
263                      * before) */
264     int flags;
265 };
266 
267 /*
268  * Used for reciprocal division/mod functions It cannot be shared between
269  * threads
270  */
271 struct bn_recp_ctx_st {
272     BIGNUM N; /* the divisor */
273     BIGNUM Nr; /* the reciprocal */
274     int num_bits;
275     int shift;
276     int flags;
277 };
278 
279 /* Used for slow "generation" functions. */
280 struct bn_gencb_st {
281     unsigned int ver; /* To handle binary (in)compatibility */
282     void *arg; /* callback-specific data */
283     union {
284         /* if (ver==1) - handles old style callbacks */
285         void (*cb_1)(int, int, void *);
286         /* if (ver==2) - new callback style */
287         int (*cb_2)(int, int, BN_GENCB *);
288     } cb;
289 };
290 
291 /*-
292  * BN_window_bits_for_exponent_size -- macro for sliding window mod_exp functions
293  *
294  *
295  * For window size 'w' (w >= 2) and a random 'b' bits exponent,
296  * the number of multiplications is a constant plus on average
297  *
298  *    2^(w-1) + (b-w)/(w+1);
299  *
300  * here  2^(w-1)  is for precomputing the table (we actually need
301  * entries only for windows that have the lowest bit set), and
302  * (b-w)/(w+1)  is an approximation for the expected number of
303  * w-bit windows, not counting the first one.
304  *
305  * Thus we should use
306  *
307  *    w >= 6  if        b > 671
308  *     w = 5  if  671 > b > 239
309  *     w = 4  if  239 > b >  79
310  *     w = 3  if   79 > b >  23
311  *    w <= 2  if   23 > b
312  *
313  * (with draws in between).  Very small exponents are often selected
314  * with low Hamming weight, so we use  w = 1  for b <= 23.
315  */
316 #define BN_window_bits_for_exponent_size(b) \
317     ((b) > 671 ? 6 : (b) > 239 ? 5          \
318             : (b) > 79         ? 4          \
319             : (b) > 23         ? 3          \
320                                : 1)
321 
322 /*
323  * BN_mod_exp_mont_consttime is based on the assumption that the L1 data cache
324  * line width of the target processor is at least the following value.
325  */
326 #define MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH (64)
327 #define MOD_EXP_CTIME_MIN_CACHE_LINE_MASK (MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH - 1)
328 
329 /*
330  * Window sizes optimized for fixed window size modular exponentiation
331  * algorithm (BN_mod_exp_mont_consttime). To achieve the security goals of
332  * BN_mode_exp_mont_consttime, the maximum size of the window must not exceed
333  * log_2(MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH). Window size thresholds are
334  * defined for cache line sizes of 32 and 64, cache line sizes where
335  * log_2(32)=5 and log_2(64)=6 respectively. A window size of 7 should only be
336  * used on processors that have a 128 byte or greater cache line size.
337  */
338 #if MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 64
339 
340 #define BN_window_bits_for_ctime_exponent_size(b) \
341     ((b) > 937 ? 6 : (b) > 306 ? 5                \
342             : (b) > 89         ? 4                \
343             : (b) > 22         ? 3                \
344                                : 1)
345 #define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE (6)
346 
347 #elif MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 32
348 
349 #define BN_window_bits_for_ctime_exponent_size(b) \
350     ((b) > 306 ? 5 : (b) > 89 ? 4                 \
351             : (b) > 22        ? 3                 \
352                               : 1)
353 #define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE (5)
354 
355 #endif
356 
357 /* Pentium pro 16,16,16,32,64 */
358 /* Alpha       16,16,16,16.64 */
359 #define BN_MULL_SIZE_NORMAL (16) /* 32 */
360 #define BN_MUL_RECURSIVE_SIZE_NORMAL (16) /* 32 less than */
361 #define BN_SQR_RECURSIVE_SIZE_NORMAL (16) /* 32 */
362 #define BN_MUL_LOW_RECURSIVE_SIZE_NORMAL (32) /* 32 */
363 #define BN_MONT_CTX_SET_SIZE_WORD (64) /* 32 */
364 
365 #if !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM) && !defined(PEDANTIC)
366 /*
367  * BN_UMULT_HIGH section.
368  * If the compiler doesn't support 2*N integer type, then you have to
369  * replace every N*N multiplication with 4 (N/2)*(N/2) accompanied by some
370  * shifts and additions which unavoidably results in severe performance
371  * penalties. Of course provided that the hardware is capable of producing
372  * 2*N result... That's when you normally start considering assembler
373  * implementation. However! It should be pointed out that some CPUs (e.g.,
374  * PowerPC, Alpha, and IA-64) provide *separate* instruction calculating
375  * the upper half of the product placing the result into a general
376  * purpose register. Now *if* the compiler supports inline assembler,
377  * then it's not impossible to implement the "bignum" routines (and have
378  * the compiler optimize 'em) exhibiting "native" performance in C. That's
379  * what BN_UMULT_HIGH macro is about:-) Note that more recent compilers do
380  * support 2*64 integer type, which is also used here.
381  */
382 #if defined(__SIZEOF_INT128__) && __SIZEOF_INT128__ == 16 && (defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG))
383 #define BN_UMULT_HIGH(a, b) (((uint128_t)(a) * (b)) >> 64)
384 #define BN_UMULT_LOHI(low, high, a, b) ({       \
385         uint128_t ret=(uint128_t)(a)*(b);   \
386         (high)=ret>>64; (low)=ret; })
387 #elif defined(__alpha) && (defined(SIXTY_FOUR_BIT_LONG) || defined(SIXTY_FOUR_BIT))
388 #if defined(__DECC)
389 #include <c_asm.h>
390 #define BN_UMULT_HIGH(a, b) (BN_ULONG) asm("umulh %a0,%a1,%v0", (a), (b))
391 #elif defined(__GNUC__) && __GNUC__ >= 2
392 #define BN_UMULT_HIGH(a, b) ({     \
393         register BN_ULONG ret;          \
394         asm ("umulh     %1,%2,%0"       \
395              : "=r"(ret)                \
396              : "r"(a), "r"(b));         \
397         ret; })
398 #endif /* compiler */
399 #elif defined(_ARCH_PPC64) && defined(SIXTY_FOUR_BIT_LONG)
400 #if defined(__GNUC__) && __GNUC__ >= 2
401 #define BN_UMULT_HIGH(a, b) ({     \
402         register BN_ULONG ret;          \
403         asm ("mulhdu    %0,%1,%2"       \
404              : "=r"(ret)                \
405              : "r"(a), "r"(b));         \
406         ret; })
407 #endif /* compiler */
408 #elif (defined(__x86_64) || defined(__x86_64__)) && (defined(SIXTY_FOUR_BIT_LONG) || defined(SIXTY_FOUR_BIT))
409 #if defined(__GNUC__) && __GNUC__ >= 2
410 #define BN_UMULT_HIGH(a, b) ({     \
411         register BN_ULONG ret,discard;  \
412         asm ("mulq      %3"             \
413              : "=a"(discard),"=d"(ret)  \
414              : "a"(a), "g"(b)           \
415              : "cc");                   \
416         ret; })
417 #define BN_UMULT_LOHI(low, high, a, b) \
418     asm("mulq      %3"                 \
419         : "=a"(low), "=d"(high)        \
420         : "a"(a), "g"(b)               \
421         : "cc");
422 #endif
423 #elif (defined(_M_AMD64) || defined(_M_X64)) && defined(SIXTY_FOUR_BIT)
424 #if defined(_MSC_VER) && _MSC_VER >= 1400
425 unsigned __int64 __umulh(unsigned __int64 a, unsigned __int64 b);
426 unsigned __int64 _umul128(unsigned __int64 a, unsigned __int64 b,
427     unsigned __int64 *h);
428 #pragma intrinsic(__umulh, _umul128)
429 #define BN_UMULT_HIGH(a, b) __umulh((a), (b))
430 #define BN_UMULT_LOHI(low, high, a, b) ((low) = _umul128((a), (b), &(high)))
431 #endif
432 #elif defined(__mips) && (defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG))
433 #if defined(__GNUC__) && __GNUC__ >= 2
434 #define BN_UMULT_HIGH(a, b) ({       \
435         register BN_ULONG ret;          \
436         asm ("dmultu    %1,%2"          \
437              : "=h"(ret)                \
438              : "r"(a), "r"(b) : "l");   \
439         ret; })
440 #define BN_UMULT_LOHI(low, high, a, b) \
441     asm("dmultu    %2,%3"              \
442         : "=l"(low), "=h"(high)        \
443         : "r"(a), "r"(b));
444 #endif
445 #elif defined(__aarch64__) && defined(SIXTY_FOUR_BIT_LONG)
446 #if defined(__GNUC__) && __GNUC__ >= 2
447 #define BN_UMULT_HIGH(a, b) ({     \
448         register BN_ULONG ret;          \
449         asm ("umulh     %0,%1,%2"       \
450              : "=r"(ret)                \
451              : "r"(a), "r"(b));         \
452         ret; })
453 #endif
454 #endif /* cpu */
455 #endif /* OPENSSL_NO_ASM */
456 
457 #ifdef BN_RAND_DEBUG
458 #define bn_clear_top2max(a)                    \
459     {                                          \
460         int ind = (a)->dmax - (a)->top;        \
461         BN_ULONG *ftl = &(a)->d[(a)->top - 1]; \
462         for (; ind != 0; ind--)                \
463             *(++ftl) = 0x0;                    \
464     }
465 #else
466 #define bn_clear_top2max(a)
467 #endif
468 
469 #ifdef BN_LLONG
470 /*******************************************************************
471  * Using the long long type, has to be twice as wide as BN_ULONG...
472  */
473 #define Lw(t) (((BN_ULONG)(t)) & BN_MASK2)
474 #define Hw(t) (((BN_ULONG)((t) >> BN_BITS2)) & BN_MASK2)
475 
476 #define mul_add(r, a, w, c)                 \
477     {                                       \
478         BN_ULLONG t;                        \
479         t = (BN_ULLONG)w * (a) + (r) + (c); \
480         (r) = Lw(t);                        \
481         (c) = Hw(t);                        \
482     }
483 
484 #define mul(r, a, w, c)               \
485     {                                 \
486         BN_ULLONG t;                  \
487         t = (BN_ULLONG)w * (a) + (c); \
488         (r) = Lw(t);                  \
489         (c) = Hw(t);                  \
490     }
491 
492 #define sqr(r0, r1, a)            \
493     {                             \
494         BN_ULLONG t;              \
495         t = (BN_ULLONG)(a) * (a); \
496         (r0) = Lw(t);             \
497         (r1) = Hw(t);             \
498     }
499 
500 #elif defined(BN_UMULT_LOHI)
501 #define mul_add(r, a, w, c)                 \
502     {                                       \
503         BN_ULONG high, low, ret, tmp = (a); \
504         ret = (r);                          \
505         BN_UMULT_LOHI(low, high, w, tmp);   \
506         ret += (c);                         \
507         (c) = (ret < (c));                  \
508         (c) += high;                        \
509         ret += low;                         \
510         (c) += (ret < low);                 \
511         (r) = ret;                          \
512     }
513 
514 #define mul(r, a, w, c)                    \
515     {                                      \
516         BN_ULONG high, low, ret, ta = (a); \
517         BN_UMULT_LOHI(low, high, w, ta);   \
518         ret = low + (c);                   \
519         (c) = high;                        \
520         (c) += (ret < low);                \
521         (r) = ret;                         \
522     }
523 
524 #define sqr(r0, r1, a)                   \
525     {                                    \
526         BN_ULONG tmp = (a);              \
527         BN_UMULT_LOHI(r0, r1, tmp, tmp); \
528     }
529 
530 #elif defined(BN_UMULT_HIGH)
531 #define mul_add(r, a, w, c)                 \
532     {                                       \
533         BN_ULONG high, low, ret, tmp = (a); \
534         ret = (r);                          \
535         high = BN_UMULT_HIGH(w, tmp);       \
536         ret += (c);                         \
537         low = (w) * tmp;                    \
538         (c) = (ret < (c));                  \
539         (c) += high;                        \
540         ret += low;                         \
541         (c) += (ret < low);                 \
542         (r) = ret;                          \
543     }
544 
545 #define mul(r, a, w, c)                    \
546     {                                      \
547         BN_ULONG high, low, ret, ta = (a); \
548         low = (w) * ta;                    \
549         high = BN_UMULT_HIGH(w, ta);       \
550         ret = low + (c);                   \
551         (c) = high;                        \
552         (c) += (ret < low);                \
553         (r) = ret;                         \
554     }
555 
556 #define sqr(r0, r1, a)                  \
557     {                                   \
558         BN_ULONG tmp = (a);             \
559         (r0) = tmp * tmp;               \
560         (r1) = BN_UMULT_HIGH(tmp, tmp); \
561     }
562 
563 #else
564 /*************************************************************
565  * No long long type
566  */
567 
568 #define LBITS(a) ((a) & BN_MASK2l)
569 #define HBITS(a) (((a) >> BN_BITS4) & BN_MASK2l)
570 #define L2HBITS(a) (((a) << BN_BITS4) & BN_MASK2)
571 
572 #define LLBITS(a) ((a) & BN_MASKl)
573 #define LHBITS(a) (((a) >> BN_BITS2) & BN_MASKl)
574 #define LL2HBITS(a) ((BN_ULLONG)((a) & BN_MASKl) << BN_BITS2)
575 
576 #define mul64(l, h, bl, bh)                \
577     {                                      \
578         BN_ULONG m, m1, lt, ht;            \
579                                            \
580         lt = l;                            \
581         ht = h;                            \
582         m = (bh) * (lt);                   \
583         lt = (bl) * (lt);                  \
584         m1 = (bl) * (ht);                  \
585         ht = (bh) * (ht);                  \
586         m = (m + m1) & BN_MASK2;           \
587         ht += L2HBITS((BN_ULONG)(m < m1)); \
588         ht += HBITS(m);                    \
589         m1 = L2HBITS(m);                   \
590         lt = (lt + m1) & BN_MASK2;         \
591         ht += (lt < m1);                   \
592         (l) = lt;                          \
593         (h) = ht;                          \
594     }
595 
596 #define sqr64(lo, ho, in)                        \
597     {                                            \
598         BN_ULONG l, h, m;                        \
599                                                  \
600         h = (in);                                \
601         l = LBITS(h);                            \
602         h = HBITS(h);                            \
603         m = (l) * (h);                           \
604         l *= l;                                  \
605         h *= h;                                  \
606         h += (m & BN_MASK2h1) >> (BN_BITS4 - 1); \
607         m = (m & BN_MASK2l) << (BN_BITS4 + 1);   \
608         l = (l + m) & BN_MASK2;                  \
609         h += (l < m);                            \
610         (lo) = l;                                \
611         (ho) = h;                                \
612     }
613 
614 #define mul_add(r, a, bl, bh, c)  \
615     {                             \
616         BN_ULONG l, h;            \
617                                   \
618         h = (a);                  \
619         l = LBITS(h);             \
620         h = HBITS(h);             \
621         mul64(l, h, (bl), (bh));  \
622                                   \
623         /* non-multiply part */   \
624         l = (l + (c)) & BN_MASK2; \
625         h += (l < (c));           \
626         (c) = (r);                \
627         l = (l + (c)) & BN_MASK2; \
628         h += (l < (c));           \
629         (c) = h & BN_MASK2;       \
630         (r) = l;                  \
631     }
632 
633 #define mul(r, a, bl, bh, c)         \
634     {                                \
635         BN_ULONG l, h;               \
636                                      \
637         h = (a);                     \
638         l = LBITS(h);                \
639         h = HBITS(h);                \
640         mul64(l, h, (bl), (bh));     \
641                                      \
642         /* non-multiply part */      \
643         l += (c);                    \
644         h += ((l & BN_MASK2) < (c)); \
645         (c) = h & BN_MASK2;          \
646         (r) = l & BN_MASK2;          \
647     }
648 #endif /* !BN_LLONG */
649 
650 void BN_RECP_CTX_init(BN_RECP_CTX *recp);
651 void BN_MONT_CTX_init(BN_MONT_CTX *ctx);
652 
653 void bn_init(BIGNUM *a);
654 void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb);
655 void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b);
656 void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b);
657 void bn_sqr_normal(BN_ULONG *r, const BN_ULONG *a, int n, BN_ULONG *tmp);
658 void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a);
659 void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a);
660 int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n);
661 int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl);
662 void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
663     int dna, int dnb, BN_ULONG *t);
664 void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b,
665     int n, int tna, int tnb, BN_ULONG *t);
666 void bn_sqr_recursive(BN_ULONG *r, const BN_ULONG *a, int n2, BN_ULONG *t);
667 void bn_mul_low_normal(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n);
668 void bn_mul_low_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
669     BN_ULONG *t);
670 BN_ULONG bn_sub_part_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
671     int cl, int dl);
672 int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
673     const BN_ULONG *np, const BN_ULONG *n0, int num);
674 void bn_correct_top_consttime(BIGNUM *a);
675 BIGNUM *int_bn_mod_inverse(BIGNUM *in,
676     const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx,
677     int *noinv);
678 
bn_expand(BIGNUM * a,int bits)679 static ossl_inline BIGNUM *bn_expand(BIGNUM *a, int bits)
680 {
681     if (bits > (INT_MAX - BN_BITS2 + 1))
682         return NULL;
683 
684     if (((bits + BN_BITS2 - 1) / BN_BITS2) <= (a)->dmax)
685         return a;
686 
687     return bn_expand2((a), (bits + BN_BITS2 - 1) / BN_BITS2);
688 }
689 
690 int ossl_bn_check_prime(const BIGNUM *w, int checks, BN_CTX *ctx,
691     int do_trial_division, BN_GENCB *cb);
692 
693 #endif
694