diff options
Diffstat (limited to 'crypto/bn/bn_lib.c')
-rw-r--r-- | crypto/bn/bn_lib.c | 262 |
1 files changed, 153 insertions, 109 deletions
diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index b6b0ce4b3c..3e4965d695 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -304,42 +304,35 @@ BIGNUM *BN_new(void) 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 *internal_bn_expand(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->dmax) + bn_check_top(b); + if (BN_get_flags(b,BN_FLG_STATIC_DATA)) { - bn_check_top(b); - if (BN_get_flags(b,BN_FLG_STATIC_DATA)) - { - BNerr(BN_F_BN_EXPAND2,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); - return(NULL); - } - a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*(words+1)); - if (A == NULL) - { - BNerr(BN_F_BN_EXPAND2,ERR_R_MALLOC_FAILURE); - return(NULL); - } + BNerr(BN_F_BN_EXPAND2,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); + return(NULL); + } + a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*(words+1)); + if (A == NULL) + { + BNerr(BN_F_BN_EXPAND2,ERR_R_MALLOC_FAILURE); + return(NULL); + } #if 1 - B=b->d; - /* Check if the previous number needs to be copied */ - if (B != NULL) - { + 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 - */ + /* 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: @@ -363,94 +356,145 @@ BIGNUM *bn_expand2(BIGNUM *b, int words) * * <appro@fy.chalmers.se> */ - 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 - */ - ; - } + 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) - { - /* - * 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:-) - * - * <appro@fy.chalmers.se> - */ - 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; - } - switch (b->top&3) - { - 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 */ - } -#endif - OPENSSL_free(b->d); + for (i=b->top>>2; i>0; i--,A+=4,B+=4) + { + /* + * 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:-) + * + * <appro@fy.chalmers.se> + */ + 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; } - - b->d=a; - b->dmax=words; - - /* Now need to zero any data between b->top and b->max */ - - A= &(b->d[b->top]); - for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8) + switch (b->top&3) { - A[0]=0; A[1]=0; A[2]=0; A[3]=0; - A[4]=0; A[5]=0; A[6]=0; A[7]=0; + 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 */ } - for (i=(b->dmax - b->top)&7; i>0; i--,A++) - A[0]=0; +#endif + } + + /* Now need to zero any data between b->top and b->max */ + + A= &(a[b->top]); + for (i=(words - 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=(words - 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; + memset(A,0,sizeof(BN_ULONG)*(words+1)); + memcpy(A,b->d,sizeof(b->d[0])*b->top); #endif -/* memset(&(p[b->max]),0,((words+1)-b->max)*sizeof(BN_ULONG)); */ -/* { int i; for (i=b->max; i<words+1; i++) p[i]=i;} */ + 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. + */ + +BIGNUM *bn_dup_expand(const BIGNUM *b, int words) + { + BIGNUM *r = NULL; + + if (words > b->dmax) + { + BN_ULONG *a = internal_bn_expand(b, words); + + if (a) + { + r = BN_new(); + r->top = b->top; + r->dmax = words; + r->neg = b->neg; + r->d = a; + } + /* Otherwise, there was an error in allocation in + internal_bn_expand(), and NULL should be returned */ + } + else + { + r = BN_dup(b); + } + + return r; + } + +/* 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) + { + if (words > b->dmax) + { + BN_ULONG *a = internal_bn_expand(b, words); + + if (a) + { + OPENSSL_free(b->d); + b->d=a; + b->dmax=words; + } + else + b = NULL; } - return(b); + return b; } BIGNUM *BN_dup(const BIGNUM *a) @@ -513,7 +557,7 @@ void BN_clear(BIGNUM *a) 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; |