diff options
Diffstat (limited to 'openssl/crypto/bn/bn_shift.c')
| -rw-r--r-- | openssl/crypto/bn/bn_shift.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/openssl/crypto/bn/bn_shift.c b/openssl/crypto/bn/bn_shift.c index c4d301afc..a6fca2c42 100644 --- a/openssl/crypto/bn/bn_shift.c +++ b/openssl/crypto/bn/bn_shift.c @@ -99,7 +99,7 @@ int BN_lshift1(BIGNUM *r, const BIGNUM *a) int BN_rshift1(BIGNUM *r, const BIGNUM *a) { BN_ULONG *ap,*rp,t,c; - int i; + int i,j; bn_check_top(r); bn_check_top(a); @@ -109,22 +109,25 @@ int BN_rshift1(BIGNUM *r, const BIGNUM *a) BN_zero(r); return(1); } + i = a->top; + ap= a->d; + j = i-(ap[i-1]==1); if (a != r) { - if (bn_wexpand(r,a->top) == NULL) return(0); - r->top=a->top; + if (bn_wexpand(r,j) == NULL) return(0); r->neg=a->neg; } - ap=a->d; rp=r->d; - c=0; - for (i=a->top-1; i>=0; i--) + t=ap[--i]; + c=(t&1)?BN_TBIT:0; + if (t>>=1) rp[i]=t; + while (i>0) { - t=ap[i]; + t=ap[--i]; rp[i]=((t>>1)&BN_MASK2)|c; c=(t&1)?BN_TBIT:0; } - bn_correct_top(r); + r->top=j; bn_check_top(r); return(1); } @@ -182,10 +185,11 @@ int BN_rshift(BIGNUM *r, const BIGNUM *a, int n) BN_zero(r); return(1); } + i = (BN_num_bits(a)-n+(BN_BITS2-1))/BN_BITS2; if (r != a) { r->neg=a->neg; - if (bn_wexpand(r,a->top-nw+1) == NULL) return(0); + if (bn_wexpand(r,i) == NULL) return(0); } else { @@ -196,7 +200,7 @@ int BN_rshift(BIGNUM *r, const BIGNUM *a, int n) f= &(a->d[nw]); t=r->d; j=a->top-nw; - r->top=j; + r->top=i; if (rb == 0) { @@ -212,9 +216,8 @@ int BN_rshift(BIGNUM *r, const BIGNUM *a, int n) l= *(f++); *(t++) =(tmp|(l<<lb))&BN_MASK2; } - *(t++) =(l>>rb)&BN_MASK2; + if ((l = (l>>rb)&BN_MASK2)) *(t) = l; } - bn_correct_top(r); bn_check_top(r); return(1); } |