diff options
Diffstat (limited to 'crypto/bn/bn_div.c')
| -rw-r--r-- | crypto/bn/bn_div.c | 68 |
1 files changed, 55 insertions, 13 deletions
diff --git a/crypto/bn/bn_div.c b/crypto/bn/bn_div.c index 2263bdc7da..c7bc04d0b4 100644 --- a/crypto/bn/bn_div.c +++ b/crypto/bn/bn_div.c @@ -72,6 +72,8 @@ BN_CTX *ctx; int i,nm,nd; BIGNUM *D; + bn_check_top(m); + bn_check_top(d); if (BN_is_zero(d)) { BNerr(BN_F_BN_DIV,BN_R_DIV_BY_ZERO); @@ -86,9 +88,9 @@ BN_CTX *ctx; return(1); } - D=ctx->bn[ctx->tos]; - if (dv == NULL) dv=ctx->bn[ctx->tos+1]; - if (rem == NULL) rem=ctx->bn[ctx->tos+2]; + D= &(ctx->bn[ctx->tos]); + if (dv == NULL) dv= &(ctx->bn[ctx->tos+1]); + if (rem == NULL) rem= &(ctx->bn[ctx->tos+2]); nd=BN_num_bits(d); nm=BN_num_bits(m); @@ -98,6 +100,7 @@ BN_CTX *ctx; /* The next 2 are needed so we can do a dv->d[0]|=1 later * since BN_lshift1 will only work once there is a value :-) */ BN_zero(dv); + bn_wexpand(dv,1); dv->top=1; if (!BN_lshift(D,D,nm-nd)) return(0); @@ -107,7 +110,7 @@ BN_CTX *ctx; if (BN_ucmp(rem,D) >= 0) { dv->d[0]|=1; - bn_qsub(rem,rem,D); + if (!BN_usub(rem,rem,D)) return(0); } /* CAN IMPROVE (and have now :=) */ if (!BN_rshift1(D,D)) return(0); @@ -132,6 +135,9 @@ BN_CTX *ctx; BN_ULONG d0,d1; int num_n,div_n; + bn_check_top(num); + bn_check_top(divisor); + if (BN_is_zero(divisor)) { BNerr(BN_F_BN_DIV,BN_R_DIV_BY_ZERO); @@ -146,12 +152,12 @@ BN_CTX *ctx; return(1); } - tmp=ctx->bn[ctx->tos]; + tmp= &(ctx->bn[ctx->tos]); tmp->neg=0; - snum=ctx->bn[ctx->tos+1]; - sdiv=ctx->bn[ctx->tos+2]; + snum= &(ctx->bn[ctx->tos+1]); + sdiv= &(ctx->bn[ctx->tos+2]); if (dv == NULL) - res=ctx->bn[ctx->tos+3]; + res= &(ctx->bn[ctx->tos+3]); else res=dv; /* First we normalise the numbers */ @@ -168,10 +174,10 @@ BN_CTX *ctx; /* Lets setup a 'window' into snum * This is the part that corresponds to the current * 'area' being divided */ + BN_init(&wnum); wnum.d= &(snum->d[loop]); wnum.top= div_n; - wnum.max= snum->max; /* a bit of a lie */ - wnum.neg= 0; + wnum.max= snum->max+1; /* a bit of a lie */ /* Get the top 2 words of sdiv */ /* i=sdiv->top; */ @@ -183,8 +189,8 @@ BN_CTX *ctx; /* Setup to 'res' */ res->neg= (num->neg^divisor->neg); - res->top=loop; if (!bn_wexpand(res,(loop+1))) goto err; + res->top=loop; resp= &(res->d[loop-1]); /* space for temp */ @@ -192,7 +198,7 @@ BN_CTX *ctx; if (BN_ucmp(&wnum,sdiv) >= 0) { - bn_qsub(&wnum,&wnum,sdiv); + if (!BN_usub(&wnum,&wnum,sdiv)) goto err; *resp=1; res->d[res->top-1]=1; } @@ -211,7 +217,7 @@ BN_CTX *ctx; if (n0 == d0) q=BN_MASK2; else - q=bn_div64(n0,n1,d0); + q=bn_div_words(n0,n1,d0); { #ifdef BN_LLONG BN_ULLONG t1,t2,rem; @@ -284,3 +290,39 @@ err: } #endif + +/* rem != m */ +int BN_mod(rem, m, d,ctx) +BIGNUM *rem; +BIGNUM *m; +BIGNUM *d; +BN_CTX *ctx; + { +#if 0 /* The old slow way */ + int i,nm,nd; + BIGNUM *dv; + + if (BN_ucmp(m,d) < 0) + return((BN_copy(rem,m) == NULL)?0:1); + + dv= &(ctx->bn[ctx->tos]); + + if (!BN_copy(rem,m)) return(0); + + nm=BN_num_bits(rem); + nd=BN_num_bits(d); + if (!BN_lshift(dv,d,nm-nd)) return(0); + for (i=nm-nd; i>=0; i--) + { + if (BN_cmp(rem,dv) >= 0) + { + if (!BN_sub(rem,rem,dv)) return(0); + } + if (!BN_rshift1(dv,dv)) return(0); + } + return(1); +#else + return(BN_div(NULL,rem,m,d,ctx)); +#endif + } + |