2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
10 #ifndef HEADER_BN_LCL_H
11 # define HEADER_BN_LCL_H
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.
18 # include <openssl/opensslconf.h>
20 # if !defined(OPENSSL_SYS_UEFI)
21 # include "internal/bn_conf.h"
24 # include "internal/bn_int.h"
31 * These preprocessor symbols control various aspects of the bignum headers
32 * and library code. They're not defined by any "normal" configuration, as
33 * they are intended for development and testing purposes. NB: defining all
34 * three can be useful for debugging application code as well as openssl
35 * itself. BN_DEBUG - turn on various debugging alterations to the bignum
36 * code BN_DEBUG_RAND - uses random poisoning of unused words to trip up
37 * mismanagement of bignum internals. You must also define BN_DEBUG.
39 /* #define BN_DEBUG */
40 /* #define BN_DEBUG_RAND */
42 # ifndef OPENSSL_SMALL_FOOTPRINT
49 * This next option uses the C libraries (2 word)/(1 word) function. If it is
50 * not defined, I use my C version (which is slower). The reason for this
51 * flag is that when the particular C compiler library routine is used, and
52 * the library is linked with a different compiler, the library is missing.
53 * This mostly happens when the library is built with gcc and then linked
54 * using normal cc. This would be a common occurrence because gcc normally
55 * produces code that is 2 times faster than system compilers for the big
56 * number stuff. For machines with only one compiler (or shared libraries),
57 * this should be on. Again this in only really a problem on machines using
58 * "long long's", are 32bit, and are not using my assembler code.
60 # if defined(OPENSSL_SYS_MSDOS) || defined(OPENSSL_SYS_WINDOWS) || \
61 defined(OPENSSL_SYS_WIN32) || defined(linux)
66 * 64-bit processor with LP64 ABI
68 # ifdef SIXTY_FOUR_BIT_LONG
69 # define BN_ULLONG unsigned long long
71 # define BN_MASK2 (0xffffffffffffffffL)
72 # define BN_MASK2l (0xffffffffL)
73 # define BN_MASK2h (0xffffffff00000000L)
74 # define BN_MASK2h1 (0xffffffff80000000L)
75 # define BN_DEC_CONV (10000000000000000000UL)
76 # define BN_DEC_NUM 19
77 # define BN_DEC_FMT1 "%lu"
78 # define BN_DEC_FMT2 "%019lu"
82 * 64-bit processor other than LP64 ABI
84 # ifdef SIXTY_FOUR_BIT
88 # define BN_MASK2 (0xffffffffffffffffLL)
89 # define BN_MASK2l (0xffffffffL)
90 # define BN_MASK2h (0xffffffff00000000LL)
91 # define BN_MASK2h1 (0xffffffff80000000LL)
92 # define BN_DEC_CONV (10000000000000000000ULL)
93 # define BN_DEC_NUM 19
94 # define BN_DEC_FMT1 "%llu"
95 # define BN_DEC_FMT2 "%019llu"
98 # ifdef THIRTY_TWO_BIT
100 # if defined(_WIN32) && !defined(__GNUC__)
101 # define BN_ULLONG unsigned __int64
103 # define BN_ULLONG unsigned long long
107 # define BN_MASK2 (0xffffffffL)
108 # define BN_MASK2l (0xffff)
109 # define BN_MASK2h1 (0xffff8000L)
110 # define BN_MASK2h (0xffff0000L)
111 # define BN_DEC_CONV (1000000000L)
112 # define BN_DEC_NUM 9
113 # define BN_DEC_FMT1 "%u"
114 # define BN_DEC_FMT2 "%09u"
119 * Bignum consistency macros
120 * There is one "API" macro, bn_fix_top(), for stripping leading zeroes from
121 * bignum data after direct manipulations on the data. There is also an
122 * "internal" macro, bn_check_top(), for verifying that there are no leading
123 * zeroes. Unfortunately, some auditing is required due to the fact that
124 * bn_fix_top() has become an overabused duct-tape because bignum data is
125 * occasionally passed around in an inconsistent state. So the following
126 * changes have been made to sort this out;
127 * - bn_fix_top()s implementation has been moved to bn_correct_top()
128 * - if BN_DEBUG isn't defined, bn_fix_top() maps to bn_correct_top(), and
129 * bn_check_top() is as before.
130 * - if BN_DEBUG *is* defined;
131 * - bn_check_top() tries to pollute unused words even if the bignum 'top' is
132 * consistent. (ed: only if BN_DEBUG_RAND is defined)
133 * - bn_fix_top() maps to bn_check_top() rather than "fixing" anything.
134 * The idea is to have debug builds flag up inconsistent bignums when they
135 * occur. If that occurs in a bn_fix_top(), we examine the code in question; if
136 * the use of bn_fix_top() was appropriate (ie. it follows directly after code
137 * that manipulates the bignum) it is converted to bn_correct_top(), and if it
138 * was not appropriate, we convert it permanently to bn_check_top() and track
139 * down the cause of the bug. Eventually, no internal code should be using the
140 * bn_fix_top() macro. External applications and libraries should try this with
141 * their own code too, both in terms of building against the openssl headers
142 * with BN_DEBUG defined *and* linking with a version of OpenSSL built with it
143 * defined. This not only improves external code, it provides more test
144 * coverage for openssl's own code.
149 /* We only need assert() when debugging */
152 # ifdef BN_DEBUG_RAND
153 /* To avoid "make update" cvs wars due to BN_DEBUG, use some tricks */
154 # ifndef RAND_pseudo_bytes
155 int RAND_pseudo_bytes(unsigned char *buf, int num);
156 # define BN_DEBUG_TRIX
158 # define bn_pollute(a) \
160 const BIGNUM *_bnum1 = (a); \
161 if (_bnum1->top < _bnum1->dmax) { \
162 unsigned char _tmp_char; \
163 /* We cast away const without the compiler knowing, any \
164 * *genuinely* constant variables that aren't mutable \
165 * wouldn't be constructed with top!=dmax. */ \
166 BN_ULONG *_not_const; \
167 memcpy(&_not_const, &_bnum1->d, sizeof(_not_const)); \
168 RAND_bytes(&_tmp_char, 1); /* Debug only - safe to ignore error return */\
169 memset(_not_const + _bnum1->top, _tmp_char, \
170 sizeof(*_not_const) * (_bnum1->dmax - _bnum1->top)); \
173 # ifdef BN_DEBUG_TRIX
174 # undef RAND_pseudo_bytes
177 # define bn_pollute(a)
179 # define bn_check_top(a) \
181 const BIGNUM *_bnum2 = (a); \
182 if (_bnum2 != NULL) { \
183 assert((_bnum2->top == 0) || \
184 (_bnum2->d[_bnum2->top - 1] != 0)); \
185 bn_pollute(_bnum2); \
189 # define bn_fix_top(a) bn_check_top(a)
191 # define bn_check_size(bn, bits) bn_wcheck_size(bn, ((bits+BN_BITS2-1))/BN_BITS2)
192 # define bn_wcheck_size(bn, words) \
194 const BIGNUM *_bnum2 = (bn); \
195 assert((words) <= (_bnum2)->dmax && (words) >= (_bnum2)->top); \
196 /* avoid unused variable warning with NDEBUG */ \
200 # else /* !BN_DEBUG */
202 # define bn_pollute(a)
203 # define bn_check_top(a)
204 # define bn_fix_top(a) bn_correct_top(a)
205 # define bn_check_size(bn, bits)
206 # define bn_wcheck_size(bn, words)
210 BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num,
212 BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w);
213 void bn_sqr_words(BN_ULONG *rp, const BN_ULONG *ap, int num);
214 BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d);
215 BN_ULONG bn_add_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
217 BN_ULONG bn_sub_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
221 BN_ULONG *d; /* Pointer to an array of 'BN_BITS2' bit
223 int top; /* Index of last used d +1. */
224 /* The next are internal book keeping for bn_expand. */
225 int dmax; /* Size of the d array. */
226 int neg; /* one if the number is negative */
230 /* Used for montgomery multiplication */
231 struct bn_mont_ctx_st {
232 int ri; /* number of bits in R */
233 BIGNUM RR; /* used to convert to montgomery form */
234 BIGNUM N; /* The modulus */
235 BIGNUM Ni; /* R*(1/R mod N) - N*Ni = 1 (Ni is only
236 * stored for bignum algorithm) */
237 BN_ULONG n0[2]; /* least significant word(s) of Ni; (type
238 * changed with 0.9.9, was "BN_ULONG n0;"
244 * Used for reciprocal division/mod functions It cannot be shared between
247 struct bn_recp_ctx_st {
248 BIGNUM N; /* the divisor */
249 BIGNUM Nr; /* the reciprocal */
255 /* Used for slow "generation" functions. */
257 unsigned int ver; /* To handle binary (in)compatibility */
258 void *arg; /* callback-specific data */
260 /* if (ver==1) - handles old style callbacks */
261 void (*cb_1) (int, int, void *);
262 /* if (ver==2) - new callback style */
263 int (*cb_2) (int, int, BN_GENCB *);
268 * BN_window_bits_for_exponent_size -- macro for sliding window mod_exp functions
271 * For window size 'w' (w >= 2) and a random 'b' bits exponent,
272 * the number of multiplications is a constant plus on average
274 * 2^(w-1) + (b-w)/(w+1);
276 * here 2^(w-1) is for precomputing the table (we actually need
277 * entries only for windows that have the lowest bit set), and
278 * (b-w)/(w+1) is an approximation for the expected number of
279 * w-bit windows, not counting the first one.
284 * w = 5 if 671 > b > 239
285 * w = 4 if 239 > b > 79
286 * w = 3 if 79 > b > 23
289 * (with draws in between). Very small exponents are often selected
290 * with low Hamming weight, so we use w = 1 for b <= 23.
292 # define BN_window_bits_for_exponent_size(b) \
299 * BN_mod_exp_mont_conttime is based on the assumption that the L1 data cache
300 * line width of the target processor is at least the following value.
302 # define MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH ( 64 )
303 # define MOD_EXP_CTIME_MIN_CACHE_LINE_MASK (MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH - 1)
306 * Window sizes optimized for fixed window size modular exponentiation
307 * algorithm (BN_mod_exp_mont_consttime). To achieve the security goals of
308 * BN_mode_exp_mont_consttime, the maximum size of the window must not exceed
309 * log_2(MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH). Window size thresholds are
310 * defined for cache line sizes of 32 and 64, cache line sizes where
311 * log_2(32)=5 and log_2(64)=6 respectively. A window size of 7 should only be
312 * used on processors that have a 128 byte or greater cache line size.
314 # if MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 64
316 # define BN_window_bits_for_ctime_exponent_size(b) \
321 # define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE (6)
323 # elif MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 32
325 # define BN_window_bits_for_ctime_exponent_size(b) \
329 # define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE (5)
333 /* Pentium pro 16,16,16,32,64 */
334 /* Alpha 16,16,16,16.64 */
335 # define BN_MULL_SIZE_NORMAL (16)/* 32 */
336 # define BN_MUL_RECURSIVE_SIZE_NORMAL (16)/* 32 less than */
337 # define BN_SQR_RECURSIVE_SIZE_NORMAL (16)/* 32 */
338 # define BN_MUL_LOW_RECURSIVE_SIZE_NORMAL (32)/* 32 */
339 # define BN_MONT_CTX_SET_SIZE_WORD (64)/* 32 */
342 * 2011-02-22 SMS. In various places, a size_t variable or a type cast to
343 * size_t was used to perform integer-only operations on pointers. This
344 * failed on VMS with 64-bit pointers (CC /POINTER_SIZE = 64) because size_t
345 * is still only 32 bits. What's needed in these cases is an integer type
346 * with the same size as a pointer, which size_t is not certain to be. The
347 * only fix here is VMS-specific.
349 # if defined(OPENSSL_SYS_VMS)
350 # if __INITIAL_POINTER_SIZE == 64
351 # define PTR_SIZE_INT long long
352 # else /* __INITIAL_POINTER_SIZE == 64 */
353 # define PTR_SIZE_INT int
354 # endif /* __INITIAL_POINTER_SIZE == 64 [else] */
355 # elif !defined(PTR_SIZE_INT) /* defined(OPENSSL_SYS_VMS) */
356 # define PTR_SIZE_INT size_t
357 # endif /* defined(OPENSSL_SYS_VMS) [else] */
359 # if !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM) && !defined(PEDANTIC)
361 * BN_UMULT_HIGH section.
363 * No, I'm not trying to overwhelm you when stating that the
364 * product of N-bit numbers is 2*N bits wide:-) No, I don't expect
365 * you to be impressed when I say that if the compiler doesn't
366 * support 2*N integer type, then you have to replace every N*N
367 * multiplication with 4 (N/2)*(N/2) accompanied by some shifts
368 * and additions which unavoidably results in severe performance
369 * penalties. Of course provided that the hardware is capable of
370 * producing 2*N result... That's when you normally start
371 * considering assembler implementation. However! It should be
372 * pointed out that some CPUs (most notably Alpha, PowerPC and
373 * upcoming IA-64 family:-) provide *separate* instruction
374 * calculating the upper half of the product placing the result
375 * into a general purpose register. Now *if* the compiler supports
376 * inline assembler, then it's not impossible to implement the
377 * "bignum" routines (and have the compiler optimize 'em)
378 * exhibiting "native" performance in C. That's what BN_UMULT_HIGH
381 * <appro@fy.chalmers.se>
383 # if defined(__alpha) && (defined(SIXTY_FOUR_BIT_LONG) || defined(SIXTY_FOUR_BIT))
386 # define BN_UMULT_HIGH(a,b) (BN_ULONG)asm("umulh %a0,%a1,%v0",(a),(b))
387 # elif defined(__GNUC__) && __GNUC__>=2
388 # define BN_UMULT_HIGH(a,b) ({ \
389 register BN_ULONG ret; \
390 asm ("umulh %1,%2,%0" \
394 # endif /* compiler */
395 # elif defined(_ARCH_PPC) && defined(__64BIT__) && defined(SIXTY_FOUR_BIT_LONG)
396 # if defined(__GNUC__) && __GNUC__>=2
397 # define BN_UMULT_HIGH(a,b) ({ \
398 register BN_ULONG ret; \
399 asm ("mulhdu %0,%1,%2" \
403 # endif /* compiler */
404 # elif (defined(__x86_64) || defined(__x86_64__)) && \
405 (defined(SIXTY_FOUR_BIT_LONG) || defined(SIXTY_FOUR_BIT))
406 # if defined(__GNUC__) && __GNUC__>=2
407 # define BN_UMULT_HIGH(a,b) ({ \
408 register BN_ULONG ret,discard; \
410 : "=a"(discard),"=d"(ret) \
414 # define BN_UMULT_LOHI(low,high,a,b) \
416 : "=a"(low),"=d"(high) \
420 # elif (defined(_M_AMD64) || defined(_M_X64)) && defined(SIXTY_FOUR_BIT)
421 # if defined(_MSC_VER) && _MSC_VER>=1400
422 unsigned __int64 __umulh(unsigned __int64 a, unsigned __int64 b);
423 unsigned __int64 _umul128(unsigned __int64 a, unsigned __int64 b,
424 unsigned __int64 *h);
425 # pragma intrinsic(__umulh,_umul128)
426 # define BN_UMULT_HIGH(a,b) __umulh((a),(b))
427 # define BN_UMULT_LOHI(low,high,a,b) ((low)=_umul128((a),(b),&(high)))
429 # elif defined(__mips) && (defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG))
430 # if defined(__GNUC__) && __GNUC__>=2
431 # if __GNUC__>4 || (__GNUC__>=4 && __GNUC_MINOR__>=4)
432 /* "h" constraint is no more since 4.4 */
433 # define BN_UMULT_HIGH(a,b) (((__uint128_t)(a)*(b))>>64)
434 # define BN_UMULT_LOHI(low,high,a,b) ({ \
435 __uint128_t ret=(__uint128_t)(a)*(b); \
436 (high)=ret>>64; (low)=ret; })
438 # define BN_UMULT_HIGH(a,b) ({ \
439 register BN_ULONG ret; \
440 asm ("dmultu %1,%2" \
442 : "r"(a), "r"(b) : "l"); \
444 # define BN_UMULT_LOHI(low,high,a,b)\
445 asm ("dmultu %2,%3" \
446 : "=l"(low),"=h"(high) \
450 # elif defined(__aarch64__) && defined(SIXTY_FOUR_BIT_LONG)
451 # if defined(__GNUC__) && __GNUC__>=2
452 # define BN_UMULT_HIGH(a,b) ({ \
453 register BN_ULONG ret; \
454 asm ("umulh %0,%1,%2" \
460 # endif /* OPENSSL_NO_ASM */
462 /*************************************************************
463 * Using the long long type
465 # define Lw(t) (((BN_ULONG)(t))&BN_MASK2)
466 # define Hw(t) (((BN_ULONG)((t)>>BN_BITS2))&BN_MASK2)
468 # ifdef BN_DEBUG_RAND
469 # define bn_clear_top2max(a) \
471 int ind = (a)->dmax - (a)->top; \
472 BN_ULONG *ftl = &(a)->d[(a)->top-1]; \
473 for (; ind != 0; ind--) \
477 # define bn_clear_top2max(a)
481 # define mul_add(r,a,w,c) { \
483 t=(BN_ULLONG)w * (a) + (r) + (c); \
488 # define mul(r,a,w,c) { \
490 t=(BN_ULLONG)w * (a) + (c); \
495 # define sqr(r0,r1,a) { \
497 t=(BN_ULLONG)(a)*(a); \
502 # elif defined(BN_UMULT_LOHI)
503 # define mul_add(r,a,w,c) { \
504 BN_ULONG high,low,ret,tmp=(a); \
506 BN_UMULT_LOHI(low,high,w,tmp); \
508 (c) = (ret<(c))?1:0; \
511 (c) += (ret<low)?1:0; \
515 # define mul(r,a,w,c) { \
516 BN_ULONG high,low,ret,ta=(a); \
517 BN_UMULT_LOHI(low,high,w,ta); \
520 (c) += (ret<low)?1:0; \
524 # define sqr(r0,r1,a) { \
526 BN_UMULT_LOHI(r0,r1,tmp,tmp); \
529 # elif defined(BN_UMULT_HIGH)
530 # define mul_add(r,a,w,c) { \
531 BN_ULONG high,low,ret,tmp=(a); \
533 high= BN_UMULT_HIGH(w,tmp); \
536 (c) = (ret<(c))?1:0; \
539 (c) += (ret<low)?1:0; \
543 # define mul(r,a,w,c) { \
544 BN_ULONG high,low,ret,ta=(a); \
546 high= BN_UMULT_HIGH(w,ta); \
549 (c) += (ret<low)?1:0; \
553 # define sqr(r0,r1,a) { \
556 (r1) = BN_UMULT_HIGH(tmp,tmp); \
560 /*************************************************************
564 # define LBITS(a) ((a)&BN_MASK2l)
565 # define HBITS(a) (((a)>>BN_BITS4)&BN_MASK2l)
566 # define L2HBITS(a) (((a)<<BN_BITS4)&BN_MASK2)
568 # define LLBITS(a) ((a)&BN_MASKl)
569 # define LHBITS(a) (((a)>>BN_BITS2)&BN_MASKl)
570 # define LL2HBITS(a) ((BN_ULLONG)((a)&BN_MASKl)<<BN_BITS2)
572 # define mul64(l,h,bl,bh) \
574 BN_ULONG m,m1,lt,ht; \
582 m=(m+m1)&BN_MASK2; if (m < m1) ht+=L2HBITS((BN_ULONG)1); \
585 lt=(lt+m1)&BN_MASK2; if (lt < m1) ht++; \
590 # define sqr64(lo,ho,in) \
600 h+=(m&BN_MASK2h1)>>(BN_BITS4-1); \
601 m =(m&BN_MASK2l)<<(BN_BITS4+1); \
602 l=(l+m)&BN_MASK2; if (l < m) h++; \
607 # define mul_add(r,a,bl,bh,c) { \
613 mul64(l,h,(bl),(bh)); \
615 /* non-multiply part */ \
616 l=(l+(c))&BN_MASK2; if (l < (c)) h++; \
618 l=(l+(c))&BN_MASK2; if (l < (c)) h++; \
623 # define mul(r,a,bl,bh,c) { \
629 mul64(l,h,(bl),(bh)); \
631 /* non-multiply part */ \
632 l+=(c); if ((l&BN_MASK2) < (c)) h++; \
636 # endif /* !BN_LLONG */
638 void BN_RECP_CTX_init(BN_RECP_CTX *recp);
639 void BN_MONT_CTX_init(BN_MONT_CTX *ctx);
641 void bn_init(BIGNUM *a);
642 void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb);
643 void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b);
644 void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b);
645 void bn_sqr_normal(BN_ULONG *r, const BN_ULONG *a, int n, BN_ULONG *tmp);
646 void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a);
647 void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a);
648 int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n);
649 int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl);
650 void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
651 int dna, int dnb, BN_ULONG *t);
652 void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b,
653 int n, int tna, int tnb, BN_ULONG *t);
654 void bn_sqr_recursive(BN_ULONG *r, const BN_ULONG *a, int n2, BN_ULONG *t);
655 void bn_mul_low_normal(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n);
656 void bn_mul_low_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
658 void bn_mul_high(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, BN_ULONG *l, int n2,
660 BN_ULONG bn_add_part_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
662 BN_ULONG bn_sub_part_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
664 int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
665 const BN_ULONG *np, const BN_ULONG *n0, int num);
667 BIGNUM *int_bn_mod_inverse(BIGNUM *in,
668 const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx,
671 int bn_probable_prime_dh(BIGNUM *rnd, int bits,
672 const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx);
673 int bn_probable_prime_dh_retry(BIGNUM *rnd, int bits, BN_CTX *ctx);
674 int bn_probable_prime_dh_coprime(BIGNUM *rnd, int bits, BN_CTX *ctx);
676 static ossl_inline BIGNUM *bn_expand(BIGNUM *a, int bits)
678 if (bits > (INT_MAX - BN_BITS2 + 1))
681 if (((bits+BN_BITS2-1)/BN_BITS2) <= (a)->dmax)
684 return bn_expand2((a),(bits+BN_BITS2-1)/BN_BITS2);