diff options
| -rw-r--r-- | crypto/bn/bn_shift.c | 48 |
1 files changed, 5 insertions, 43 deletions
diff --git a/crypto/bn/bn_shift.c b/crypto/bn/bn_shift.c index b1f8dbd2d3..cdf66933e9 100644 --- a/crypto/bn/bn_shift.c +++ b/crypto/bn/bn_shift.c @@ -152,57 +152,19 @@ int bn_lshift_fixed_top(BIGNUM *r, const BIGNUM *a, int n) int BN_rshift(BIGNUM *r, const BIGNUM *a, int n) { - int i, j, nw, lb, rb; - BN_ULONG *t, *f; - BN_ULONG l, tmp; - - bn_check_top(r); - bn_check_top(a); + int ret = 0; if (n < 0) { BNerr(BN_F_BN_RSHIFT, BN_R_INVALID_SHIFT); return 0; } - nw = n / BN_BITS2; - rb = n % BN_BITS2; - lb = BN_BITS2 - rb; - if (nw >= a->top || a->top == 0) { - BN_zero(r); - return 1; - } - i = (BN_num_bits(a) - n + (BN_BITS2 - 1)) / BN_BITS2; - if (r != a) { - if (bn_wexpand(r, i) == NULL) - return 0; - r->neg = a->neg; - } else { - if (n == 0) - return 1; /* or the copying loop will go berserk */ - } - - f = &(a->d[nw]); - t = r->d; - j = a->top - nw; - r->top = i; + ret = bn_rshift_fixed_top(r, a, n); - if (rb == 0) { - for (i = j; i != 0; i--) - *(t++) = *(f++); - } else { - l = *(f++); - for (i = j - 1; i != 0; i--) { - tmp = (l >> rb) & BN_MASK2; - l = *(f++); - *(t++) = (tmp | (l << lb)) & BN_MASK2; - } - if ((l = (l >> rb) & BN_MASK2)) - *(t) = l; - } - if (!r->top) - r->neg = 0; /* don't allow negative zero */ + bn_correct_top(r); bn_check_top(r); - return 1; + + return ret; } /* |