diff options
Diffstat (limited to 'crypto/bn/bn_shift.c')
-rw-r--r-- | crypto/bn/bn_shift.c | 283 |
1 files changed, 136 insertions, 147 deletions
diff --git a/crypto/bn/bn_shift.c b/crypto/bn/bn_shift.c index c4d301afc4..67904c99c5 100644 --- a/crypto/bn/bn_shift.c +++ b/crypto/bn/bn_shift.c @@ -5,21 +5,21 @@ * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. - * + * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). - * + * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. - * + * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: @@ -34,10 +34,10 @@ * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). - * 4. If you include any Windows specific code (or a derivative thereof) from + * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" - * + * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE @@ -49,7 +49,7 @@ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. - * + * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence @@ -61,160 +61,149 @@ #include "bn_lcl.h" int BN_lshift1(BIGNUM *r, const BIGNUM *a) - { - register BN_ULONG *ap,*rp,t,c; - int i; +{ + register BN_ULONG *ap, *rp, t, c; + int i; - bn_check_top(r); - bn_check_top(a); + bn_check_top(r); + bn_check_top(a); - if (r != a) - { - r->neg=a->neg; - if (bn_wexpand(r,a->top+1) == NULL) return(0); - r->top=a->top; - } - else - { - if (bn_wexpand(r,a->top+1) == NULL) return(0); - } - ap=a->d; - rp=r->d; - c=0; - 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++; - } - bn_check_top(r); - return(1); - } + if (r != a) { + r->neg = a->neg; + if (bn_wexpand(r, a->top + 1) == NULL) + return (0); + r->top = a->top; + } else { + if (bn_wexpand(r, a->top + 1) == NULL) + return (0); + } + ap = a->d; + rp = r->d; + c = 0; + 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++; + } + bn_check_top(r); + return (1); +} int BN_rshift1(BIGNUM *r, const BIGNUM *a) - { - BN_ULONG *ap,*rp,t,c; - int i; +{ + BN_ULONG *ap, *rp, t, c; + int i; - bn_check_top(r); - bn_check_top(a); + bn_check_top(r); + bn_check_top(a); - if (BN_is_zero(a)) - { - BN_zero(r); - return(1); - } - if (a != r) - { - if (bn_wexpand(r,a->top) == NULL) return(0); - r->top=a->top; - r->neg=a->neg; - } - ap=a->d; - rp=r->d; - c=0; - for (i=a->top-1; i>=0; i--) - { - t=ap[i]; - rp[i]=((t>>1)&BN_MASK2)|c; - c=(t&1)?BN_TBIT:0; - } - bn_correct_top(r); - bn_check_top(r); - return(1); - } + if (BN_is_zero(a)) { + BN_zero(r); + return (1); + } + if (a != r) { + if (bn_wexpand(r, a->top) == NULL) + return (0); + r->top = a->top; + r->neg = a->neg; + } + ap = a->d; + rp = r->d; + c = 0; + for (i = a->top - 1; i >= 0; i--) { + t = ap[i]; + rp[i] = ((t >> 1) & BN_MASK2) | c; + c = (t & 1) ? BN_TBIT : 0; + } + bn_correct_top(r); + bn_check_top(r); + return (1); +} int BN_lshift(BIGNUM *r, const BIGNUM *a, int n) - { - int i,nw,lb,rb; - BN_ULONG *t,*f; - BN_ULONG l; +{ + int i, nw, lb, rb; + BN_ULONG *t, *f; + BN_ULONG l; - bn_check_top(r); - bn_check_top(a); + bn_check_top(r); + bn_check_top(a); - r->neg=a->neg; - nw=n/BN_BITS2; - if (bn_wexpand(r,a->top+nw+1) == NULL) return(0); - lb=n%BN_BITS2; - rb=BN_BITS2-lb; - f=a->d; - t=r->d; - t[a->top+nw]=0; - if (lb == 0) - for (i=a->top-1; i>=0; i--) - t[nw+i]=f[i]; - else - for (i=a->top-1; i>=0; i--) - { - l=f[i]; - t[nw+i+1]|=(l>>rb)&BN_MASK2; - t[nw+i]=(l<<lb)&BN_MASK2; - } - memset(t,0,nw*sizeof(t[0])); -/* for (i=0; i<nw; i++) - t[i]=0;*/ - r->top=a->top+nw+1; - bn_correct_top(r); - bn_check_top(r); - return(1); - } + r->neg = a->neg; + nw = n / BN_BITS2; + if (bn_wexpand(r, a->top + nw + 1) == NULL) + return (0); + lb = n % BN_BITS2; + rb = BN_BITS2 - lb; + f = a->d; + t = r->d; + t[a->top + nw] = 0; + if (lb == 0) + for (i = a->top - 1; i >= 0; i--) + t[nw + i] = f[i]; + else + for (i = a->top - 1; i >= 0; i--) { + l = f[i]; + t[nw + i + 1] |= (l >> rb) & BN_MASK2; + t[nw + i] = (l << lb) & BN_MASK2; + } + memset(t, 0, nw * sizeof(t[0])); + /* + * for (i=0; i<nw; i++) t[i]=0; + */ + r->top = a->top + nw + 1; + bn_correct_top(r); + bn_check_top(r); + return (1); +} int BN_rshift(BIGNUM *r, const BIGNUM *a, int n) - { - int i,j,nw,lb,rb; - BN_ULONG *t,*f; - BN_ULONG l,tmp; +{ + int i, j, nw, lb, rb; + BN_ULONG *t, *f; + BN_ULONG l, tmp; - bn_check_top(r); - bn_check_top(a); + bn_check_top(r); + bn_check_top(a); - nw=n/BN_BITS2; - rb=n%BN_BITS2; - lb=BN_BITS2-rb; - if (nw >= a->top || a->top == 0) - { - BN_zero(r); - return(1); - } - if (r != a) - { - r->neg=a->neg; - if (bn_wexpand(r,a->top-nw+1) == NULL) return(0); - } - else - { - if (n == 0) - return 1; /* or the copying loop will go berserk */ - } + nw = n / BN_BITS2; + rb = n % BN_BITS2; + lb = BN_BITS2 - rb; + if (nw >= a->top || a->top == 0) { + BN_zero(r); + return (1); + } + if (r != a) { + r->neg = a->neg; + if (bn_wexpand(r, a->top - nw + 1) == NULL) + return (0); + } 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=j; + f = &(a->d[nw]); + t = r->d; + j = a->top - nw; + r->top = j; - 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; - } - *(t++) =(l>>rb)&BN_MASK2; - } - bn_correct_top(r); - bn_check_top(r); - return(1); - } + 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; + } + *(t++) = (l >> rb) & BN_MASK2; + } + bn_correct_top(r); + bn_check_top(r); + return (1); +} |