diff options
Diffstat (limited to 'crypto/bn/bn_add.c')
-rw-r--r-- | crypto/bn/bn_add.c | 432 |
1 files changed, 215 insertions, 217 deletions
diff --git a/crypto/bn/bn_add.c b/crypto/bn/bn_add.c index 042103ccac..c48665a038 100644 --- a/crypto/bn/bn_add.c +++ b/crypto/bn/bn_add.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 @@ -62,254 +62,252 @@ /* r can == a or b */ int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) - { - const BIGNUM *tmp; - int a_neg = a->neg, ret; +{ + const BIGNUM *tmp; + int a_neg = a->neg, ret; - bn_check_top(a); - bn_check_top(b); + bn_check_top(a); + bn_check_top(b); - /*- - * a + b a+b - * a + -b a-b - * -a + b b-a - * -a + -b -(a+b) - */ - if (a_neg ^ b->neg) - { - /* only one is negative */ - if (a_neg) - { tmp=a; a=b; b=tmp; } + /*- + * a + b a+b + * a + -b a-b + * -a + b b-a + * -a + -b -(a+b) + */ + if (a_neg ^ b->neg) { + /* only one is negative */ + if (a_neg) { + tmp = a; + a = b; + b = tmp; + } - /* we are now a - b */ + /* we are now a - b */ - if (BN_ucmp(a,b) < 0) - { - if (!BN_usub(r,b,a)) return(0); - r->neg=1; - } - else - { - if (!BN_usub(r,a,b)) return(0); - r->neg=0; - } - return(1); - } + if (BN_ucmp(a, b) < 0) { + if (!BN_usub(r, b, a)) + return (0); + r->neg = 1; + } else { + if (!BN_usub(r, a, b)) + return (0); + r->neg = 0; + } + return (1); + } - ret = BN_uadd(r,a,b); - r->neg = a_neg; - bn_check_top(r); - return ret; - } + ret = BN_uadd(r, a, b); + r->neg = a_neg; + bn_check_top(r); + return ret; +} /* unsigned add of b to a */ int BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) - { - int max,min,dif; - BN_ULONG *ap,*bp,*rp,carry,t1,t2; - const BIGNUM *tmp; +{ + int max, min, dif; + BN_ULONG *ap, *bp, *rp, carry, t1, t2; + const BIGNUM *tmp; - bn_check_top(a); - bn_check_top(b); + bn_check_top(a); + bn_check_top(b); - if (a->top < b->top) - { tmp=a; a=b; b=tmp; } - max = a->top; - min = b->top; - dif = max - min; + if (a->top < b->top) { + tmp = a; + a = b; + b = tmp; + } + max = a->top; + min = b->top; + dif = max - min; - if (bn_wexpand(r,max+1) == NULL) - return 0; + if (bn_wexpand(r, max + 1) == NULL) + return 0; - r->top=max; + r->top = max; + ap = a->d; + bp = b->d; + rp = r->d; - ap=a->d; - bp=b->d; - rp=r->d; + carry = bn_add_words(rp, ap, bp, min); + rp += min; + ap += min; + bp += min; - carry=bn_add_words(rp,ap,bp,min); - rp+=min; - ap+=min; - bp+=min; - - if (carry) - { - while (dif) - { - dif--; - t1 = *(ap++); - t2 = (t1+1) & BN_MASK2; - *(rp++) = t2; - if (t2) - { - carry=0; - break; - } - } - if (carry) - { - /* carry != 0 => dif == 0 */ - *rp = 1; - r->top++; - } - } - if (dif && rp != ap) - while (dif--) - /* copy remaining words if ap != rp */ - *(rp++) = *(ap++); - r->neg = 0; - bn_check_top(r); - return 1; - } + if (carry) { + while (dif) { + dif--; + t1 = *(ap++); + t2 = (t1 + 1) & BN_MASK2; + *(rp++) = t2; + if (t2) { + carry = 0; + break; + } + } + if (carry) { + /* carry != 0 => dif == 0 */ + *rp = 1; + r->top++; + } + } + if (dif && rp != ap) + while (dif--) + /* copy remaining words if ap != rp */ + *(rp++) = *(ap++); + r->neg = 0; + bn_check_top(r); + return 1; +} /* unsigned subtraction of b from a, a must be larger than b. */ int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) - { - int max,min,dif; - register BN_ULONG t1,t2,*ap,*bp,*rp; - int i,carry; +{ + int max, min, dif; + register BN_ULONG t1, t2, *ap, *bp, *rp; + int i, carry; #if defined(IRIX_CC_BUG) && !defined(LINT) - int dummy; + int dummy; #endif - bn_check_top(a); - bn_check_top(b); + bn_check_top(a); + bn_check_top(b); - max = a->top; - min = b->top; - dif = max - min; + max = a->top; + min = b->top; + dif = max - min; - if (dif < 0) /* hmm... should not be happening */ - { - BNerr(BN_F_BN_USUB,BN_R_ARG2_LT_ARG3); - return(0); - } + if (dif < 0) { /* hmm... should not be happening */ + BNerr(BN_F_BN_USUB, BN_R_ARG2_LT_ARG3); + return (0); + } - if (bn_wexpand(r,max) == NULL) return(0); + if (bn_wexpand(r, max) == NULL) + return (0); - ap=a->d; - bp=b->d; - rp=r->d; + ap = a->d; + bp = b->d; + rp = r->d; #if 1 - carry=0; - for (i = min; i != 0; i--) - { - t1= *(ap++); - t2= *(bp++); - if (carry) - { - carry=(t1 <= t2); - t1=(t1-t2-1)&BN_MASK2; - } - else - { - carry=(t1 < t2); - t1=(t1-t2)&BN_MASK2; - } -#if defined(IRIX_CC_BUG) && !defined(LINT) - dummy=t1; -#endif - *(rp++)=t1&BN_MASK2; - } + carry = 0; + for (i = min; i != 0; i--) { + t1 = *(ap++); + t2 = *(bp++); + if (carry) { + carry = (t1 <= t2); + t1 = (t1 - t2 - 1) & BN_MASK2; + } else { + carry = (t1 < t2); + t1 = (t1 - t2) & BN_MASK2; + } +# if defined(IRIX_CC_BUG) && !defined(LINT) + dummy = t1; +# endif + *(rp++) = t1 & BN_MASK2; + } #else - carry=bn_sub_words(rp,ap,bp,min); - ap+=min; - bp+=min; - rp+=min; + carry = bn_sub_words(rp, ap, bp, min); + ap += min; + bp += min; + rp += min; #endif - if (carry) /* subtracted */ - { - if (!dif) - /* error: a < b */ - return 0; - while (dif) - { - dif--; - t1 = *(ap++); - t2 = (t1-1)&BN_MASK2; - *(rp++) = t2; - if (t1) - break; - } - } + if (carry) { /* subtracted */ + if (!dif) + /* error: a < b */ + return 0; + while (dif) { + dif--; + t1 = *(ap++); + t2 = (t1 - 1) & BN_MASK2; + *(rp++) = t2; + if (t1) + break; + } + } #if 0 - memcpy(rp,ap,sizeof(*rp)*(max-i)); + memcpy(rp, ap, sizeof(*rp) * (max - i)); #else - if (rp != ap) - { - for (;;) - { - if (!dif--) break; - rp[0]=ap[0]; - if (!dif--) break; - rp[1]=ap[1]; - if (!dif--) break; - rp[2]=ap[2]; - if (!dif--) break; - rp[3]=ap[3]; - rp+=4; - ap+=4; - } - } + if (rp != ap) { + for (;;) { + if (!dif--) + break; + rp[0] = ap[0]; + if (!dif--) + break; + rp[1] = ap[1]; + if (!dif--) + break; + rp[2] = ap[2]; + if (!dif--) + break; + rp[3] = ap[3]; + rp += 4; + ap += 4; + } + } #endif - r->top=max; - r->neg=0; - bn_correct_top(r); - return(1); - } + r->top = max; + r->neg = 0; + bn_correct_top(r); + return (1); +} int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) - { - int max; - int add=0,neg=0; - const BIGNUM *tmp; - - bn_check_top(a); - bn_check_top(b); +{ + int max; + int add = 0, neg = 0; + const BIGNUM *tmp; - /*- - * a - b a-b - * a - -b a+b - * -a - b -(a+b) - * -a - -b b-a - */ - if (a->neg) - { - if (b->neg) - { tmp=a; a=b; b=tmp; } - else - { add=1; neg=1; } - } - else - { - if (b->neg) { add=1; neg=0; } - } + bn_check_top(a); + bn_check_top(b); - if (add) - { - if (!BN_uadd(r,a,b)) return(0); - r->neg=neg; - return(1); - } + /*- + * a - b a-b + * a - -b a+b + * -a - b -(a+b) + * -a - -b b-a + */ + if (a->neg) { + if (b->neg) { + tmp = a; + a = b; + b = tmp; + } else { + add = 1; + neg = 1; + } + } else { + if (b->neg) { + add = 1; + neg = 0; + } + } - /* We are actually doing a - b :-) */ + if (add) { + if (!BN_uadd(r, a, b)) + return (0); + r->neg = neg; + return (1); + } - max=(a->top > b->top)?a->top:b->top; - if (bn_wexpand(r,max) == NULL) return(0); - if (BN_ucmp(a,b) < 0) - { - if (!BN_usub(r,b,a)) return(0); - r->neg=1; - } - else - { - if (!BN_usub(r,a,b)) return(0); - r->neg=0; - } - bn_check_top(r); - return(1); - } + /* We are actually doing a - b :-) */ + max = (a->top > b->top) ? a->top : b->top; + if (bn_wexpand(r, max) == NULL) + return (0); + if (BN_ucmp(a, b) < 0) { + if (!BN_usub(r, b, a)) + return (0); + r->neg = 1; + } else { + if (!BN_usub(r, a, b)) + return (0); + r->neg = 0; + } + bn_check_top(r); + return (1); +} |