X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_lib.c;h=b1e224bb4dc19bbcfec662057179b8860ea67c05;hp=81e5d7d98e8d804d8150e6c58ea467f47cd8ead7;hb=2514fa79acba998c2a8d4e5a8288a5b3ae990377;hpb=26a3a48d65c7464b400ec1de439994d7f0d25fed diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index 81e5d7d98e..b1e224bb4d 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -56,12 +56,24 @@ * [including the GNU Public Licence.] */ +#ifndef BN_DEBUG +# undef NDEBUG /* avoid conflicting definitions */ +# define NDEBUG +#endif + +#define OPENSSL_FIPSAPI + +#include +#include #include #include "cryptlib.h" #include "bn_lcl.h" -const char *BN_version="Big Number" OPENSSL_VERSION_PTEXT; +__fips_constseg +const char BN_version[]="Big Number" OPENSSL_VERSION_PTEXT; +/* This stuff appears to be completely unused, so is deprecated */ +#ifndef OPENSSL_NO_DEPRECATED /* For a 32 bit machine * 2 - 4 == 128 * 3 - 8 == 256 @@ -84,28 +96,28 @@ void BN_set_params(int mult, int high, int low, int mont) { if (mult >= 0) { - if (mult > (sizeof(int)*8)-1) + if (mult > (int)(sizeof(int)*8)-1) mult=sizeof(int)*8-1; bn_limit_bits=mult; bn_limit_num=1<= 0) { - if (high > (sizeof(int)*8)-1) + if (high > (int)(sizeof(int)*8)-1) high=sizeof(int)*8-1; bn_limit_bits_high=high; bn_limit_num_high=1<= 0) { - if (low > (sizeof(int)*8)-1) + if (low > (int)(sizeof(int)*8)-1) low=sizeof(int)*8-1; bn_limit_bits_low=low; bn_limit_num_low=1<= 0) { - if (mont > (sizeof(int)*8)-1) + if (mont > (int)(sizeof(int)*8)-1) mont=sizeof(int)*8-1; bn_limit_bits_mont=mont; bn_limit_num_mont=1<>8)]+8); else @@ -237,22 +232,11 @@ int BN_num_bits_word(BN_ULONG l) int BN_num_bits(const BIGNUM *a) { - BN_ULONG l; - int i; - + int i = a->top - 1; bn_check_top(a); - if (a->top == 0) return(0); - l=a->d[a->top-1]; - i=(a->top-1)*BN_BITS2; - if (l == 0) - { -#if !defined(NO_STDIO) && !defined(WIN16) - fprintf(stderr,"BAD TOP VALUE\n"); -#endif - abort(); - } - return(i+BN_num_bits_word(l)); + if (BN_is_zero(a)) return 0; + return ((i*BN_BITS2) + BN_num_bits_word(a->d[i])); } void BN_clear_free(BIGNUM *a) @@ -260,14 +244,15 @@ void BN_clear_free(BIGNUM *a) int i; if (a == NULL) return; + bn_check_top(a); if (a->d != NULL) { - memset(a->d,0,a->max*sizeof(a->d[0])); + OPENSSL_cleanse(a->d,a->dmax*sizeof(a->d[0])); if (!(BN_get_flags(a,BN_FLG_STATIC_DATA))) OPENSSL_free(a->d); } i=BN_get_flags(a,BN_FLG_MALLOCED); - memset(a,0,sizeof(BIGNUM)); + OPENSSL_cleanse(a,sizeof(BIGNUM)); if (i) OPENSSL_free(a); } @@ -275,16 +260,24 @@ void BN_clear_free(BIGNUM *a) void BN_free(BIGNUM *a) { if (a == NULL) return; + bn_check_top(a); if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA))) OPENSSL_free(a->d); - a->flags|=BN_FLG_FREE; /* REMOVE? */ if (a->flags & BN_FLG_MALLOCED) OPENSSL_free(a); + else + { +#ifndef OPENSSL_NO_DEPRECATED + a->flags|=BN_FLG_FREE; +#endif + a->d = NULL; + } } void BN_init(BIGNUM *a) { memset(a,0,sizeof(BIGNUM)); + bn_check_top(a); } BIGNUM *BN_new(void) @@ -299,171 +292,191 @@ BIGNUM *BN_new(void) ret->flags=BN_FLG_MALLOCED; ret->top=0; ret->neg=0; - ret->max=0; + ret->dmax=0; ret->d=NULL; + bn_check_top(ret); return(ret); } -/* This is an internal function that should not be used in applications. - * It ensures that 'b' has enough room for a 'words' word number number. - * It is mostly used by the various BIGNUM routines. If there is an error, - * NULL is returned. If not, 'b' is returned. */ - -BIGNUM *bn_expand2(BIGNUM *b, int words) +/* This is used both by bn_expand2() and bn_dup_expand() */ +/* The caller MUST check that words > b->dmax before calling this */ +static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) { - BN_ULONG *A,*a; + BN_ULONG *A,*a = NULL; const BN_ULONG *B; int i; bn_check_top(b); - if (words > b->max) + if (words > (INT_MAX/(4*BN_BITS2))) + { + BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_BIGNUM_TOO_LONG); + return NULL; + } + if (BN_get_flags(b,BN_FLG_STATIC_DATA)) + { + BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); + return(NULL); + } + a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*words); + if (A == NULL) + { + BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE); + return(NULL); + } +#if 1 + B=b->d; + /* Check if the previous number needs to be copied */ + if (B != NULL) { - bn_check_top(b); - if (BN_get_flags(b,BN_FLG_STATIC_DATA)) + for (i=b->top>>2; i>0; i--,A+=4,B+=4) { - BNerr(BN_F_BN_EXPAND2,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); - return(NULL); + /* + * The fact that the loop is unrolled + * 4-wise is a tribute to Intel. It's + * the one that doesn't have enough + * registers to accomodate more data. + * I'd unroll it 8-wise otherwise:-) + * + * + */ + BN_ULONG a0,a1,a2,a3; + a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3]; + A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3; } - a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*(words+1)); - if (A == NULL) + switch (b->top&3) { - BNerr(BN_F_BN_EXPAND2,ERR_R_MALLOC_FAILURE); - return(NULL); + case 3: A[2]=B[2]; + case 2: A[1]=B[1]; + case 1: A[0]=B[0]; + case 0: /* workaround for ultrix cc: without 'case 0', the optimizer does + * the switch table by doing a=top&3; a--; goto jump_table[a]; + * which fails for top== 0 */ + ; } -#if 1 - B=b->d; - /* Check if the previous number needs to be copied */ - if (B != NULL) - { -#if 0 - /* This lot is an unrolled loop to copy b->top - * BN_ULONGs from B to A - */ -/* - * I have nothing against unrolling but it's usually done for - * several reasons, namely: - * - minimize percentage of decision making code, i.e. branches; - * - avoid cache trashing; - * - make it possible to schedule loads earlier; - * Now let's examine the code below. The cornerstone of C is - * "programmer is always right" and that's what we love it for:-) - * For this very reason C compilers have to be paranoid when it - * comes to data aliasing and assume the worst. Yeah, but what - * does it mean in real life? This means that loop body below will - * be compiled to sequence of loads immediately followed by stores - * as compiler assumes the worst, something in A==B+1 style. As a - * result CPU pipeline is going to starve for incoming data. Secondly - * if A and B happen to share same cache line such code is going to - * cause severe cache trashing. Both factors have severe impact on - * performance of modern CPUs and this is the reason why this - * particular piece of code is #ifdefed away and replaced by more - * "friendly" version found in #else section below. This comment - * also applies to BN_copy function. - * - * - */ - for (i=b->top&(~7); i>0; i-=8) - { - A[0]=B[0]; A[1]=B[1]; A[2]=B[2]; A[3]=B[3]; - A[4]=B[4]; A[5]=B[5]; A[6]=B[6]; A[7]=B[7]; - A+=8; - B+=8; - } - switch (b->top&7) - { - case 7: - A[6]=B[6]; - case 6: - A[5]=B[5]; - case 5: - A[4]=B[4]; - case 4: - A[3]=B[3]; - case 3: - A[2]=B[2]; - case 2: - A[1]=B[1]; - case 1: - A[0]=B[0]; - case 0: - /* I need the 'case 0' entry for utrix cc. - * If the optimizer is turned on, it does the - * switch table by doing - * a=top&7 - * a--; - * goto jump_table[a]; - * If top is 0, this makes us jump to 0xffffffc - * which is rather bad :-(. - * eric 23-Apr-1998 - */ - ; - } + } + #else - for (i=b->top>>2; i>0; i--,A+=4,B+=4) + memset(A,0,sizeof(BN_ULONG)*words); + memcpy(A,b->d,sizeof(b->d[0])*b->top); +#endif + + return(a); + } + +/* This is an internal function that can be used instead of bn_expand2() + * when there is a need to copy BIGNUMs instead of only expanding the + * data part, while still expanding them. + * Especially useful when needing to expand BIGNUMs that are declared + * 'const' and should therefore not be changed. + * The reason to use this instead of a BN_dup() followed by a bn_expand2() + * is memory allocation overhead. A BN_dup() followed by a bn_expand2() + * will allocate new memory for the BIGNUM data twice, and free it once, + * while bn_dup_expand() makes sure allocation is made only once. + */ + +#ifndef OPENSSL_NO_DEPRECATED +BIGNUM *bn_dup_expand(const BIGNUM *b, int words) + { + BIGNUM *r = NULL; + + bn_check_top(b); + + /* This function does not work if + * words <= b->dmax && top < words + * because BN_dup() does not preserve 'dmax'! + * (But bn_dup_expand() is not used anywhere yet.) + */ + + if (words > b->dmax) + { + BN_ULONG *a = bn_expand_internal(b, words); + + if (a) + { + r = BN_new(); + if (r) { - /* - * The fact that the loop is unrolled - * 4-wise is a tribute to Intel. It's - * the one that doesn't have enough - * registers to accomodate more data. - * I'd unroll it 8-wise otherwise:-) - * - * - */ - BN_ULONG a0,a1,a2,a3; - a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3]; - A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3; + r->top = b->top; + r->dmax = words; + r->neg = b->neg; + r->d = a; } - switch (b->top&3) + else { - case 3: A[2]=B[2]; - case 2: A[1]=B[1]; - case 1: A[0]=B[0]; - case 0: ; /* ultrix cc workaround, see above */ + /* r == NULL, BN_new failure */ + OPENSSL_free(a); } -#endif - OPENSSL_free(b->d); } + /* If a == NULL, there was an error in allocation in + bn_expand_internal(), and NULL should be returned */ + } + else + { + r = BN_dup(b); + } - b->d=a; - b->max=words; + bn_check_top(r); + return r; + } +#endif - /* Now need to zero any data between b->top and b->max */ +/* This is an internal function that should not be used in applications. + * It ensures that 'b' has enough room for a 'words' word number + * and initialises any unused part of b->d with leading zeros. + * It is mostly used by the various BIGNUM routines. If there is an error, + * NULL is returned. If not, 'b' is returned. */ - A= &(b->d[b->top]); - for (i=(b->max - b->top)>>3; i>0; i--,A+=8) +BIGNUM *bn_expand2(BIGNUM *b, int words) + { + bn_check_top(b); + + if (words > b->dmax) + { + BN_ULONG *a = bn_expand_internal(b, words); + if(!a) return NULL; + if(b->d) OPENSSL_free(b->d); + b->d=a; + b->dmax=words; + } + +/* None of this should be necessary because of what b->top means! */ +#if 0 + /* NB: bn_wexpand() calls this only if the BIGNUM really has to grow */ + if (b->top < b->dmax) + { + int i; + BN_ULONG *A = &(b->d[b->top]); + for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8) { A[0]=0; A[1]=0; A[2]=0; A[3]=0; A[4]=0; A[5]=0; A[6]=0; A[7]=0; } - for (i=(b->max - b->top)&7; i>0; i--,A++) + for (i=(b->dmax - b->top)&7; i>0; i--,A++) A[0]=0; -#else - memset(A,0,sizeof(BN_ULONG)*(words+1)); - memcpy(A,b->d,sizeof(b->d[0])*b->top); - b->d=a; - b->max=words; -#endif - -/* memset(&(p[b->max]),0,((words+1)-b->max)*sizeof(BN_ULONG)); */ -/* { int i; for (i=b->max; id[b->dmax])); } - return(b); +#endif + bn_check_top(b); + return b; } BIGNUM *BN_dup(const BIGNUM *a) { - BIGNUM *r; + BIGNUM *t; if (a == NULL) return NULL; - bn_check_top(a); - r=BN_new(); - if (r == NULL) return(NULL); - return((BIGNUM *)BN_copy(r,a)); + t = BN_new(); + if (t == NULL) return NULL; + if(!BN_copy(t, a)) + { + BN_free(t); + return NULL; + } + bn_check_top(t); + return t; } BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) @@ -491,85 +504,92 @@ BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) case 3: A[2]=B[2]; case 2: A[1]=B[1]; case 1: A[0]=B[0]; - case 0: ; /* ultrix cc workaround, see comments in bn_expand2 */ + case 0: ; /* ultrix cc workaround, see comments in bn_expand_internal */ } #else memcpy(a->d,b->d,sizeof(b->d[0])*b->top); #endif -/* memset(&(a->d[b->top]),0,sizeof(a->d[0])*(a->max-b->top));*/ a->top=b->top; - if ((a->top == 0) && (a->d != NULL)) - a->d[0]=0; a->neg=b->neg; + bn_check_top(a); return(a); } +void BN_swap(BIGNUM *a, BIGNUM *b) + { + int flags_old_a, flags_old_b; + BN_ULONG *tmp_d; + int tmp_top, tmp_dmax, tmp_neg; + + bn_check_top(a); + bn_check_top(b); + + flags_old_a = a->flags; + flags_old_b = b->flags; + + tmp_d = a->d; + tmp_top = a->top; + tmp_dmax = a->dmax; + tmp_neg = a->neg; + + a->d = b->d; + a->top = b->top; + a->dmax = b->dmax; + a->neg = b->neg; + + b->d = tmp_d; + b->top = tmp_top; + b->dmax = tmp_dmax; + b->neg = tmp_neg; + + a->flags = (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA); + b->flags = (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA); + bn_check_top(a); + bn_check_top(b); + } + void BN_clear(BIGNUM *a) { + bn_check_top(a); if (a->d != NULL) - memset(a->d,0,a->max*sizeof(a->d[0])); + memset(a->d,0,a->dmax*sizeof(a->d[0])); a->top=0; a->neg=0; } -BN_ULONG BN_get_word(BIGNUM *a) +BN_ULONG BN_get_word(const BIGNUM *a) { - int i,n; - BN_ULONG ret=0; - - n=BN_num_bytes(a); - if (n > sizeof(BN_ULONG)) - return(BN_MASK2); - for (i=a->top-1; i>=0; i--) - { -#ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */ - ret<<=BN_BITS4; /* stops the compiler complaining */ - ret<<=BN_BITS4; -#else - ret=0; -#endif - ret|=a->d[i]; - } - return(ret); + if (a->top > 1) + return BN_MASK2; + else if (a->top == 1) + return a->d[0]; + /* a->top == 0 */ + return 0; } int BN_set_word(BIGNUM *a, BN_ULONG w) { - int i,n; - if (bn_expand(a,sizeof(BN_ULONG)*8) == NULL) return(0); - - n=sizeof(BN_ULONG)/BN_BYTES; - a->neg=0; - a->top=0; - a->d[0]=(BN_ULONG)w&BN_MASK2; - if (a->d[0] != 0) a->top=1; - for (i=1; i>=BN_BITS2 so compilers don't complain - * on builds where sizeof(long) == BN_TYPES */ -#ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */ - w>>=BN_BITS4; - w>>=BN_BITS4; -#else - w=0; -#endif - a->d[i]=(BN_ULONG)w&BN_MASK2; - if (a->d[i] != 0) a->top=i+1; - } + bn_check_top(a); + if (bn_expand(a,(int)sizeof(BN_ULONG)*8) == NULL) return(0); + a->neg = 0; + a->d[0] = w; + a->top = (w ? 1 : 0); + bn_check_top(a); return(1); } -/* ignore negative */ BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) { unsigned int i,m; unsigned int n; BN_ULONG l; + BIGNUM *bn = NULL; - if (ret == NULL) ret=BN_new(); + if (ret == NULL) + ret = bn = BN_new(); if (ret == NULL) return(NULL); + bn_check_top(ret); l=0; n=len; if (n == 0) @@ -577,12 +597,16 @@ BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) ret->top=0; return(ret); } - if (bn_expand(ret,(int)(n+2)*8) == NULL) - return(NULL); i=((n-1)/BN_BYTES)+1; m=((n-1)%(BN_BYTES)); + if (bn_wexpand(ret, (int)i) == NULL) + { + if (bn) BN_free(bn); + return NULL; + } ret->top=i; - while (n-- > 0) + ret->neg=0; + while (n--) { l=(l<<8L)| *(s++); if (m-- == 0) @@ -594,7 +618,7 @@ BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) } /* need to call this due to clear byte at top if avoiding * having the top bit set (-ve number) */ - bn_fix_top(ret); + bn_correct_top(ret); return(ret); } @@ -604,8 +628,9 @@ int BN_bn2bin(const BIGNUM *a, unsigned char *to) int n,i; BN_ULONG l; + bn_check_top(a); n=i=BN_num_bytes(a); - while (i-- > 0) + while (i--) { l=a->d[i/BN_BYTES]; *(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff; @@ -630,7 +655,7 @@ int BN_ucmp(const BIGNUM *a, const BIGNUM *b) t1= ap[i]; t2= bp[i]; if (t1 != t2) - return(t1 > t2?1:-1); + return((t1 > t2) ? 1 : -1); } return(0); } @@ -680,6 +705,9 @@ int BN_set_bit(BIGNUM *a, int n) { int i,j,k; + if (n < 0) + return 0; + i=n/BN_BITS2; j=n%BN_BITS2; if (a->top <= i) @@ -691,6 +719,7 @@ int BN_set_bit(BIGNUM *a, int n) } a->d[i]|=(((BN_ULONG)1)<top <= i) return(0); a->d[i]&=(~(((BN_ULONG)1)<top <= i) return(0); - return((a->d[i]&(((BN_ULONG)1)<top <= i) return 0; + return (int)(((a->d[i])>>j)&((BN_ULONG)1)); } int BN_mask_bits(BIGNUM *a, int n) { int b,w; + bn_check_top(a); + if (n < 0) return 0; + w=n/BN_BITS2; b=n%BN_BITS2; - if (w >= a->top) return(0); + if (w >= a->top) return 0; if (b == 0) a->top=w; else @@ -732,11 +768,19 @@ int BN_mask_bits(BIGNUM *a, int n) a->top=w+1; a->d[w]&= ~(BN_MASK2<neg = 1; + else + a->neg = 0; + } + +int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n) { int i; BN_ULONG aa,bb; @@ -753,3 +797,111 @@ int bn_cmp_words(BN_ULONG *a, BN_ULONG *b, int n) return(0); } +/* Here follows a specialised variants of bn_cmp_words(). It has the + property of performing the operation on arrays of different sizes. + The sizes of those arrays is expressed through cl, which is the + common length ( basicall, min(len(a),len(b)) ), and dl, which is the + delta between the two lengths, calculated as len(a)-len(b). + All lengths are the number of BN_ULONGs... */ + +int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, + int cl, int dl) + { + int n,i; + n = cl-1; + + if (dl < 0) + { + for (i=dl; i<0; i++) + { + if (b[n-i] != 0) + return -1; /* a < b */ + } + } + if (dl > 0) + { + for (i=dl; i>0; i--) + { + if (a[n+i] != 0) + return 1; /* a > b */ + } + } + return bn_cmp_words(a,b,cl); + } + +/* + * Constant-time conditional swap of a and b. + * a and b are swapped if condition is not 0. The code assumes that at most one bit of condition is set. + * nwords is the number of words to swap. The code assumes that at least nwords are allocated in both a and b, + * and that no more than nwords are used by either a or b. + * a and b cannot be the same number + */ +void BN_consttime_swap(BN_ULONG condition, BIGNUM *a, BIGNUM *b, int nwords) + { + BN_ULONG t; + int i; + + bn_wcheck_size(a, nwords); + bn_wcheck_size(b, nwords); + + assert(a != b); + assert((condition & (condition - 1)) == 0); + assert(sizeof(BN_ULONG) >= sizeof(int)); + + condition = ((condition - 1) >> (BN_BITS2 - 1)) - 1; + + t = (a->top^b->top) & condition; + a->top ^= t; + b->top ^= t; + +#define BN_CONSTTIME_SWAP(ind) \ + do { \ + t = (a->d[ind] ^ b->d[ind]) & condition; \ + a->d[ind] ^= t; \ + b->d[ind] ^= t; \ + } while (0) + + + switch (nwords) { + default: + for (i = 10; i < nwords; i++) + BN_CONSTTIME_SWAP(i); + /* Fallthrough */ + case 10: BN_CONSTTIME_SWAP(9); /* Fallthrough */ + case 9: BN_CONSTTIME_SWAP(8); /* Fallthrough */ + case 8: BN_CONSTTIME_SWAP(7); /* Fallthrough */ + case 7: BN_CONSTTIME_SWAP(6); /* Fallthrough */ + case 6: BN_CONSTTIME_SWAP(5); /* Fallthrough */ + case 5: BN_CONSTTIME_SWAP(4); /* Fallthrough */ + case 4: BN_CONSTTIME_SWAP(3); /* Fallthrough */ + case 3: BN_CONSTTIME_SWAP(2); /* Fallthrough */ + case 2: BN_CONSTTIME_SWAP(1); /* Fallthrough */ + case 1: BN_CONSTTIME_SWAP(0); + } +#undef BN_CONSTTIME_SWAP +} + +/* Bits of security, see SP800-57 */ + +int BN_security_bits(int L, int N) + { + int secbits, bits; + if (L >= 15360) + secbits = 256; + else if (L >= 7690) + secbits = 192; + else if (L >= 3072) + secbits = 128; + else if (L >= 2048) + secbits = 112; + else if (L >= 1024) + secbits = 80; + else + return 0; + if (N == -1) + return secbits; + bits = N / 2; + if (bits < 80) + return 0; + return bits >= secbits ? secbits : bits; + }