diff options
Diffstat (limited to 'crypto/openssl/crypto/bn/bn_shift.c')
-rw-r--r-- | crypto/openssl/crypto/bn/bn_shift.c | 73 |
1 files changed, 16 insertions, 57 deletions
diff --git a/crypto/openssl/crypto/bn/bn_shift.c b/crypto/openssl/crypto/bn/bn_shift.c index b7a1e0ff9ae3..210a83f586d2 100644 --- a/crypto/openssl/crypto/bn/bn_shift.c +++ b/crypto/openssl/crypto/bn/bn_shift.c @@ -9,7 +9,7 @@ #include <assert.h> #include "internal/cryptlib.h" -#include "bn_lcl.h" +#include "bn_local.h" int BN_lshift1(BIGNUM *r, const BIGNUM *a) { @@ -34,12 +34,10 @@ int BN_lshift1(BIGNUM *r, const BIGNUM *a) for (i = 0; i < a->top; i++) { t = *(ap++); *(rp++) = ((t << 1) | c) & BN_MASK2; - c = (t & BN_TBIT) ? 1 : 0; - } - if (c) { - *rp = 1; - r->top++; + c = t >> (BN_BITS2 - 1); } + *rp = c; + r->top += c; bn_check_top(r); return 1; } @@ -47,7 +45,7 @@ int BN_lshift1(BIGNUM *r, const BIGNUM *a) int BN_rshift1(BIGNUM *r, const BIGNUM *a) { BN_ULONG *ap, *rp, t, c; - int i, j; + int i; bn_check_top(r); bn_check_top(a); @@ -58,23 +56,22 @@ int BN_rshift1(BIGNUM *r, const BIGNUM *a) } i = a->top; ap = a->d; - j = i - (ap[i - 1] == 1); if (a != r) { - if (bn_wexpand(r, j) == NULL) + if (bn_wexpand(r, i) == NULL) return 0; r->neg = a->neg; } rp = r->d; + r->top = i; t = ap[--i]; - c = (t & 1) ? BN_TBIT : 0; - if (t >>= 1) - rp[i] = t; + rp[i] = t >> 1; + c = t << (BN_BITS2 - 1); + r->top -= (t == 1); while (i > 0) { t = ap[--i]; rp[i] = ((t >> 1) & BN_MASK2) | c; - c = (t & 1) ? BN_TBIT : 0; + c = t << (BN_BITS2 - 1); } - r->top = j; if (!r->top) r->neg = 0; /* don't allow negative zero */ bn_check_top(r); @@ -152,57 +149,19 @@ 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; } /* |