diff options
Diffstat (limited to 'crypto/bn/bn_mul.c')
-rw-r--r-- | crypto/bn/bn_mul.c | 1999 |
1 files changed, 993 insertions, 1006 deletions
diff --git a/crypto/bn/bn_mul.c b/crypto/bn/bn_mul.c index f53985d750..3b751d3edc 100644 --- a/crypto/bn/bn_mul.c +++ b/crypto/bn/bn_mul.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 @@ -57,7 +57,7 @@ */ #ifndef BN_DEBUG -# undef NDEBUG /* avoid conflicting definitions */ +# undef NDEBUG /* avoid conflicting definitions */ # define NDEBUG #endif @@ -67,317 +67,350 @@ #include "bn_lcl.h" #if defined(OPENSSL_NO_ASM) || !defined(OPENSSL_BN_ASM_PART_WORDS) -/* Here follows specialised variants of bn_add_words() and - bn_sub_words(). They have the property performing operations on - arrays of different sizes. The sizes of those arrays is expressed through - cl, which is the common length ( basicall, min(len(a),len(b)) ), and dl, - which is the delta between the two lengths, calculated as len(a)-len(b). - All lengths are the number of BN_ULONGs... For the operations that require - a result array as parameter, it must have the length cl+abs(dl). - These functions should probably end up in bn_asm.c as soon as there are - assembler counterparts for the systems that use assembler files. */ +/* + * Here follows specialised variants of bn_add_words() and bn_sub_words(). + * They have the property performing operations on arrays of different sizes. + * The sizes of those arrays is expressed through cl, which is the common + * length ( basicall, min(len(a),len(b)) ), and dl, which is the delta + * between the two lengths, calculated as len(a)-len(b). All lengths are the + * number of BN_ULONGs... For the operations that require a result array as + * parameter, it must have the length cl+abs(dl). These functions should + * probably end up in bn_asm.c as soon as there are assembler counterparts + * for the systems that use assembler files. + */ BN_ULONG bn_sub_part_words(BN_ULONG *r, - const BN_ULONG *a, const BN_ULONG *b, - int cl, int dl) - { - BN_ULONG c, t; + const BN_ULONG *a, const BN_ULONG *b, + int cl, int dl) +{ + BN_ULONG c, t; - assert(cl >= 0); - c = bn_sub_words(r, a, b, cl); + assert(cl >= 0); + c = bn_sub_words(r, a, b, cl); - if (dl == 0) - return c; + if (dl == 0) + return c; - r += cl; - a += cl; - b += cl; + r += cl; + a += cl; + b += cl; - if (dl < 0) - { -#ifdef BN_COUNT - fprintf(stderr, " bn_sub_part_words %d + %d (dl < 0, c = %d)\n", cl, dl, c); -#endif - for (;;) - { - t = b[0]; - r[0] = (0-t-c)&BN_MASK2; - if (t != 0) c=1; - if (++dl >= 0) break; - - t = b[1]; - r[1] = (0-t-c)&BN_MASK2; - if (t != 0) c=1; - if (++dl >= 0) break; - - t = b[2]; - r[2] = (0-t-c)&BN_MASK2; - if (t != 0) c=1; - if (++dl >= 0) break; - - t = b[3]; - r[3] = (0-t-c)&BN_MASK2; - if (t != 0) c=1; - if (++dl >= 0) break; - - b += 4; - r += 4; - } - } - else - { - int save_dl = dl; -#ifdef BN_COUNT - fprintf(stderr, " bn_sub_part_words %d + %d (dl > 0, c = %d)\n", cl, dl, c); -#endif - while(c) - { - t = a[0]; - r[0] = (t-c)&BN_MASK2; - if (t != 0) c=0; - if (--dl <= 0) break; - - t = a[1]; - r[1] = (t-c)&BN_MASK2; - if (t != 0) c=0; - if (--dl <= 0) break; - - t = a[2]; - r[2] = (t-c)&BN_MASK2; - if (t != 0) c=0; - if (--dl <= 0) break; - - t = a[3]; - r[3] = (t-c)&BN_MASK2; - if (t != 0) c=0; - if (--dl <= 0) break; - - save_dl = dl; - a += 4; - r += 4; - } - if (dl > 0) - { -#ifdef BN_COUNT - fprintf(stderr, " bn_sub_part_words %d + %d (dl > 0, c == 0)\n", cl, dl); -#endif - if (save_dl > dl) - { - switch (save_dl - dl) - { - case 1: - r[1] = a[1]; - if (--dl <= 0) break; - case 2: - r[2] = a[2]; - if (--dl <= 0) break; - case 3: - r[3] = a[3]; - if (--dl <= 0) break; - } - a += 4; - r += 4; - } - } - if (dl > 0) - { -#ifdef BN_COUNT - fprintf(stderr, " bn_sub_part_words %d + %d (dl > 0, copy)\n", cl, dl); -#endif - for(;;) - { - r[0] = a[0]; - if (--dl <= 0) break; - r[1] = a[1]; - if (--dl <= 0) break; - r[2] = a[2]; - if (--dl <= 0) break; - r[3] = a[3]; - if (--dl <= 0) break; - - a += 4; - r += 4; - } - } - } - return c; - } + if (dl < 0) { +# ifdef BN_COUNT + fprintf(stderr, " bn_sub_part_words %d + %d (dl < 0, c = %d)\n", cl, + dl, c); +# endif + for (;;) { + t = b[0]; + r[0] = (0 - t - c) & BN_MASK2; + if (t != 0) + c = 1; + if (++dl >= 0) + break; + + t = b[1]; + r[1] = (0 - t - c) & BN_MASK2; + if (t != 0) + c = 1; + if (++dl >= 0) + break; + + t = b[2]; + r[2] = (0 - t - c) & BN_MASK2; + if (t != 0) + c = 1; + if (++dl >= 0) + break; + + t = b[3]; + r[3] = (0 - t - c) & BN_MASK2; + if (t != 0) + c = 1; + if (++dl >= 0) + break; + + b += 4; + r += 4; + } + } else { + int save_dl = dl; +# ifdef BN_COUNT + fprintf(stderr, " bn_sub_part_words %d + %d (dl > 0, c = %d)\n", cl, + dl, c); +# endif + while (c) { + t = a[0]; + r[0] = (t - c) & BN_MASK2; + if (t != 0) + c = 0; + if (--dl <= 0) + break; + + t = a[1]; + r[1] = (t - c) & BN_MASK2; + if (t != 0) + c = 0; + if (--dl <= 0) + break; + + t = a[2]; + r[2] = (t - c) & BN_MASK2; + if (t != 0) + c = 0; + if (--dl <= 0) + break; + + t = a[3]; + r[3] = (t - c) & BN_MASK2; + if (t != 0) + c = 0; + if (--dl <= 0) + break; + + save_dl = dl; + a += 4; + r += 4; + } + if (dl > 0) { +# ifdef BN_COUNT + fprintf(stderr, " bn_sub_part_words %d + %d (dl > 0, c == 0)\n", + cl, dl); +# endif + if (save_dl > dl) { + switch (save_dl - dl) { + case 1: + r[1] = a[1]; + if (--dl <= 0) + break; + case 2: + r[2] = a[2]; + if (--dl <= 0) + break; + case 3: + r[3] = a[3]; + if (--dl <= 0) + break; + } + a += 4; + r += 4; + } + } + if (dl > 0) { +# ifdef BN_COUNT + fprintf(stderr, " bn_sub_part_words %d + %d (dl > 0, copy)\n", + cl, dl); +# endif + for (;;) { + r[0] = a[0]; + if (--dl <= 0) + break; + r[1] = a[1]; + if (--dl <= 0) + break; + r[2] = a[2]; + if (--dl <= 0) + break; + r[3] = a[3]; + if (--dl <= 0) + break; + + a += 4; + r += 4; + } + } + } + return c; +} #endif BN_ULONG bn_add_part_words(BN_ULONG *r, - const BN_ULONG *a, const BN_ULONG *b, - int cl, int dl) - { - BN_ULONG c, l, t; + const BN_ULONG *a, const BN_ULONG *b, + int cl, int dl) +{ + BN_ULONG c, l, t; - assert(cl >= 0); - c = bn_add_words(r, a, b, cl); + assert(cl >= 0); + c = bn_add_words(r, a, b, cl); - if (dl == 0) - return c; + if (dl == 0) + return c; - r += cl; - a += cl; - b += cl; + r += cl; + a += cl; + b += cl; - if (dl < 0) - { - int save_dl = dl; + if (dl < 0) { + int save_dl = dl; #ifdef BN_COUNT - fprintf(stderr, " bn_add_part_words %d + %d (dl < 0, c = %d)\n", cl, dl, c); + fprintf(stderr, " bn_add_part_words %d + %d (dl < 0, c = %d)\n", cl, + dl, c); #endif - while (c) - { - l=(c+b[0])&BN_MASK2; - c=(l < c); - r[0]=l; - if (++dl >= 0) break; - - l=(c+b[1])&BN_MASK2; - c=(l < c); - r[1]=l; - if (++dl >= 0) break; - - l=(c+b[2])&BN_MASK2; - c=(l < c); - r[2]=l; - if (++dl >= 0) break; - - l=(c+b[3])&BN_MASK2; - c=(l < c); - r[3]=l; - if (++dl >= 0) break; - - save_dl = dl; - b+=4; - r+=4; - } - if (dl < 0) - { + while (c) { + l = (c + b[0]) & BN_MASK2; + c = (l < c); + r[0] = l; + if (++dl >= 0) + break; + + l = (c + b[1]) & BN_MASK2; + c = (l < c); + r[1] = l; + if (++dl >= 0) + break; + + l = (c + b[2]) & BN_MASK2; + c = (l < c); + r[2] = l; + if (++dl >= 0) + break; + + l = (c + b[3]) & BN_MASK2; + c = (l < c); + r[3] = l; + if (++dl >= 0) + break; + + save_dl = dl; + b += 4; + r += 4; + } + if (dl < 0) { #ifdef BN_COUNT - fprintf(stderr, " bn_add_part_words %d + %d (dl < 0, c == 0)\n", cl, dl); + fprintf(stderr, " bn_add_part_words %d + %d (dl < 0, c == 0)\n", + cl, dl); #endif - if (save_dl < dl) - { - switch (dl - save_dl) - { - case 1: - r[1] = b[1]; - if (++dl >= 0) break; - case 2: - r[2] = b[2]; - if (++dl >= 0) break; - case 3: - r[3] = b[3]; - if (++dl >= 0) break; - } - b += 4; - r += 4; - } - } - if (dl < 0) - { + if (save_dl < dl) { + switch (dl - save_dl) { + case 1: + r[1] = b[1]; + if (++dl >= 0) + break; + case 2: + r[2] = b[2]; + if (++dl >= 0) + break; + case 3: + r[3] = b[3]; + if (++dl >= 0) + break; + } + b += 4; + r += 4; + } + } + if (dl < 0) { #ifdef BN_COUNT - fprintf(stderr, " bn_add_part_words %d + %d (dl < 0, copy)\n", cl, dl); + fprintf(stderr, " bn_add_part_words %d + %d (dl < 0, copy)\n", + cl, dl); #endif - for(;;) - { - r[0] = b[0]; - if (++dl >= 0) break; - r[1] = b[1]; - if (++dl >= 0) break; - r[2] = b[2]; - if (++dl >= 0) break; - r[3] = b[3]; - if (++dl >= 0) break; - - b += 4; - r += 4; - } - } - } - else - { - int save_dl = dl; + for (;;) { + r[0] = b[0]; + if (++dl >= 0) + break; + r[1] = b[1]; + if (++dl >= 0) + break; + r[2] = b[2]; + if (++dl >= 0) + break; + r[3] = b[3]; + if (++dl >= 0) + break; + + b += 4; + r += 4; + } + } + } else { + int save_dl = dl; #ifdef BN_COUNT - fprintf(stderr, " bn_add_part_words %d + %d (dl > 0)\n", cl, dl); + fprintf(stderr, " bn_add_part_words %d + %d (dl > 0)\n", cl, dl); #endif - while (c) - { - t=(a[0]+c)&BN_MASK2; - c=(t < c); - r[0]=t; - if (--dl <= 0) break; - - t=(a[1]+c)&BN_MASK2; - c=(t < c); - r[1]=t; - if (--dl <= 0) break; - - t=(a[2]+c)&BN_MASK2; - c=(t < c); - r[2]=t; - if (--dl <= 0) break; - - t=(a[3]+c)&BN_MASK2; - c=(t < c); - r[3]=t; - if (--dl <= 0) break; - - save_dl = dl; - a+=4; - r+=4; - } + while (c) { + t = (a[0] + c) & BN_MASK2; + c = (t < c); + r[0] = t; + if (--dl <= 0) + break; + + t = (a[1] + c) & BN_MASK2; + c = (t < c); + r[1] = t; + if (--dl <= 0) + break; + + t = (a[2] + c) & BN_MASK2; + c = (t < c); + r[2] = t; + if (--dl <= 0) + break; + + t = (a[3] + c) & BN_MASK2; + c = (t < c); + r[3] = t; + if (--dl <= 0) + break; + + save_dl = dl; + a += 4; + r += 4; + } #ifdef BN_COUNT - fprintf(stderr, " bn_add_part_words %d + %d (dl > 0, c == 0)\n", cl, dl); + fprintf(stderr, " bn_add_part_words %d + %d (dl > 0, c == 0)\n", cl, + dl); #endif - if (dl > 0) - { - if (save_dl > dl) - { - switch (save_dl - dl) - { - case 1: - r[1] = a[1]; - if (--dl <= 0) break; - case 2: - r[2] = a[2]; - if (--dl <= 0) break; - case 3: - r[3] = a[3]; - if (--dl <= 0) break; - } - a += 4; - r += 4; - } - } - if (dl > 0) - { + if (dl > 0) { + if (save_dl > dl) { + switch (save_dl - dl) { + case 1: + r[1] = a[1]; + if (--dl <= 0) + break; + case 2: + r[2] = a[2]; + if (--dl <= 0) + break; + case 3: + r[3] = a[3]; + if (--dl <= 0) + break; + } + a += 4; + r += 4; + } + } + if (dl > 0) { #ifdef BN_COUNT - fprintf(stderr, " bn_add_part_words %d + %d (dl > 0, copy)\n", cl, dl); + fprintf(stderr, " bn_add_part_words %d + %d (dl > 0, copy)\n", + cl, dl); #endif - for(;;) - { - r[0] = a[0]; - if (--dl <= 0) break; - r[1] = a[1]; - if (--dl <= 0) break; - r[2] = a[2]; - if (--dl <= 0) break; - r[3] = a[3]; - if (--dl <= 0) break; - - a += 4; - r += 4; - } - } - } - return c; - } + for (;;) { + r[0] = a[0]; + if (--dl <= 0) + break; + r[1] = a[1]; + if (--dl <= 0) + break; + r[2] = a[2]; + if (--dl <= 0) + break; + r[3] = a[3]; + if (--dl <= 0) + break; + + a += 4; + r += 4; + } + } + } + return c; +} #ifdef BN_RECURSION -/* Karatsuba recursive multiplication algorithm - * (cf. Knuth, The Art of Computer Programming, Vol. 2) */ +/* + * Karatsuba recursive multiplication algorithm (cf. Knuth, The Art of + * Computer Programming, Vol. 2) + */ /*- * r is 2*n2 words in size, @@ -392,368 +425,339 @@ BN_ULONG bn_add_part_words(BN_ULONG *r, */ /* dnX may not be positive, but n2/2+dnX has to be */ void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2, - int dna, int dnb, BN_ULONG *t) - { - int n=n2/2,c1,c2; - int tna=n+dna, tnb=n+dnb; - unsigned int neg,zero; - BN_ULONG ln,lo,*p; + int dna, int dnb, BN_ULONG *t) +{ + int n = n2 / 2, c1, c2; + int tna = n + dna, tnb = n + dnb; + unsigned int neg, zero; + BN_ULONG ln, lo, *p; # ifdef BN_COUNT - fprintf(stderr," bn_mul_recursive %d%+d * %d%+d\n",n2,dna,n2,dnb); + fprintf(stderr, " bn_mul_recursive %d%+d * %d%+d\n", n2, dna, n2, dnb); # endif # ifdef BN_MUL_COMBA # if 0 - if (n2 == 4) - { - bn_mul_comba4(r,a,b); - return; - } + if (n2 == 4) { + bn_mul_comba4(r, a, b); + return; + } # endif - /* Only call bn_mul_comba 8 if n2 == 8 and the - * two arrays are complete [steve] - */ - if (n2 == 8 && dna == 0 && dnb == 0) - { - bn_mul_comba8(r,a,b); - return; - } -# endif /* BN_MUL_COMBA */ - /* Else do normal multiply */ - if (n2 < BN_MUL_RECURSIVE_SIZE_NORMAL) - { - bn_mul_normal(r,a,n2+dna,b,n2+dnb); - if ((dna + dnb) < 0) - memset(&r[2*n2 + dna + dnb], 0, - sizeof(BN_ULONG) * -(dna + dnb)); - return; - } - /* r=(a[0]-a[1])*(b[1]-b[0]) */ - c1=bn_cmp_part_words(a,&(a[n]),tna,n-tna); - c2=bn_cmp_part_words(&(b[n]),b,tnb,tnb-n); - zero=neg=0; - switch (c1*3+c2) - { - case -4: - bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */ - bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */ - break; - case -3: - zero=1; - break; - case -2: - bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */ - bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); /* + */ - neg=1; - break; - case -1: - case 0: - case 1: - zero=1; - break; - case 2: - bn_sub_part_words(t, a, &(a[n]),tna,n-tna); /* + */ - bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */ - neg=1; - break; - case 3: - zero=1; - break; - case 4: - bn_sub_part_words(t, a, &(a[n]),tna,n-tna); - bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); - break; - } + /* + * Only call bn_mul_comba 8 if n2 == 8 and the two arrays are complete + * [steve] + */ + if (n2 == 8 && dna == 0 && dnb == 0) { + bn_mul_comba8(r, a, b); + return; + } +# endif /* BN_MUL_COMBA */ + /* Else do normal multiply */ + if (n2 < BN_MUL_RECURSIVE_SIZE_NORMAL) { + bn_mul_normal(r, a, n2 + dna, b, n2 + dnb); + if ((dna + dnb) < 0) + memset(&r[2 * n2 + dna + dnb], 0, + sizeof(BN_ULONG) * -(dna + dnb)); + return; + } + /* r=(a[0]-a[1])*(b[1]-b[0]) */ + c1 = bn_cmp_part_words(a, &(a[n]), tna, n - tna); + c2 = bn_cmp_part_words(&(b[n]), b, tnb, tnb - n); + zero = neg = 0; + switch (c1 * 3 + c2) { + case -4: + bn_sub_part_words(t, &(a[n]), a, tna, tna - n); /* - */ + bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb); /* - */ + break; + case -3: + zero = 1; + break; + case -2: + bn_sub_part_words(t, &(a[n]), a, tna, tna - n); /* - */ + bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n); /* + */ + neg = 1; + break; + case -1: + case 0: + case 1: + zero = 1; + break; + case 2: + bn_sub_part_words(t, a, &(a[n]), tna, n - tna); /* + */ + bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb); /* - */ + neg = 1; + break; + case 3: + zero = 1; + break; + case 4: + bn_sub_part_words(t, a, &(a[n]), tna, n - tna); + bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n); + break; + } # ifdef BN_MUL_COMBA - if (n == 4 && dna == 0 && dnb == 0) /* XXX: bn_mul_comba4 could take - extra args to do this well */ - { - if (!zero) - bn_mul_comba4(&(t[n2]),t,&(t[n])); - else - memset(&(t[n2]),0,8*sizeof(BN_ULONG)); - - bn_mul_comba4(r,a,b); - bn_mul_comba4(&(r[n2]),&(a[n]),&(b[n])); - } - else if (n == 8 && dna == 0 && dnb == 0) /* XXX: bn_mul_comba8 could - take extra args to do this - well */ - { - if (!zero) - bn_mul_comba8(&(t[n2]),t,&(t[n])); - else - memset(&(t[n2]),0,16*sizeof(BN_ULONG)); - - bn_mul_comba8(r,a,b); - bn_mul_comba8(&(r[n2]),&(a[n]),&(b[n])); - } - else -# endif /* BN_MUL_COMBA */ - { - p= &(t[n2*2]); - if (!zero) - bn_mul_recursive(&(t[n2]),t,&(t[n]),n,0,0,p); - else - memset(&(t[n2]),0,n2*sizeof(BN_ULONG)); - bn_mul_recursive(r,a,b,n,0,0,p); - bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),n,dna,dnb,p); - } - - /*- - * t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign - * r[10] holds (a[0]*b[0]) - * r[32] holds (b[1]*b[1]) - */ - - c1=(int)(bn_add_words(t,r,&(r[n2]),n2)); - - if (neg) /* if t[32] is negative */ - { - c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2)); - } - else - { - /* Might have a carry */ - c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),t,n2)); - } - - /*- - * t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1]) - * r[10] holds (a[0]*b[0]) - * r[32] holds (b[1]*b[1]) - * c1 holds the carry bits - */ - c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2)); - if (c1) - { - p= &(r[n+n2]); - lo= *p; - ln=(lo+c1)&BN_MASK2; - *p=ln; - - /* The overflow will stop before we over write - * words we should not overwrite */ - if (ln < (BN_ULONG)c1) - { - do { - p++; - lo= *p; - ln=(lo+1)&BN_MASK2; - *p=ln; - } while (ln == 0); - } - } - } - -/* n+tn is the word length - * t needs to be n*4 is size, as does r */ + if (n == 4 && dna == 0 && dnb == 0) { /* XXX: bn_mul_comba4 could take + * extra args to do this well */ + if (!zero) + bn_mul_comba4(&(t[n2]), t, &(t[n])); + else + memset(&(t[n2]), 0, 8 * sizeof(BN_ULONG)); + + bn_mul_comba4(r, a, b); + bn_mul_comba4(&(r[n2]), &(a[n]), &(b[n])); + } else if (n == 8 && dna == 0 && dnb == 0) { /* XXX: bn_mul_comba8 could + * take extra args to do + * this well */ + if (!zero) + bn_mul_comba8(&(t[n2]), t, &(t[n])); + else + memset(&(t[n2]), 0, 16 * sizeof(BN_ULONG)); + + bn_mul_comba8(r, a, b); + bn_mul_comba8(&(r[n2]), &(a[n]), &(b[n])); + } else +# endif /* BN_MUL_COMBA */ + { + p = &(t[n2 * 2]); + if (!zero) + bn_mul_recursive(&(t[n2]), t, &(t[n]), n, 0, 0, p); + else + memset(&(t[n2]), 0, n2 * sizeof(BN_ULONG)); + bn_mul_recursive(r, a, b, n, 0, 0, p); + bn_mul_recursive(&(r[n2]), &(a[n]), &(b[n]), n, dna, dnb, p); + } + + /*- + * t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign + * r[10] holds (a[0]*b[0]) + * r[32] holds (b[1]*b[1]) + */ + + c1 = (int)(bn_add_words(t, r, &(r[n2]), n2)); + + if (neg) { /* if t[32] is negative */ + c1 -= (int)(bn_sub_words(&(t[n2]), t, &(t[n2]), n2)); + } else { + /* Might have a carry */ + c1 += (int)(bn_add_words(&(t[n2]), &(t[n2]), t, n2)); + } + + /*- + * t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1]) + * r[10] holds (a[0]*b[0]) + * r[32] holds (b[1]*b[1]) + * c1 holds the carry bits + */ + c1 += (int)(bn_add_words(&(r[n]), &(r[n]), &(t[n2]), n2)); + if (c1) { + p = &(r[n + n2]); + lo = *p; + ln = (lo + c1) & BN_MASK2; + *p = ln; + + /* + * The overflow will stop before we over write words we should not + * overwrite + */ + if (ln < (BN_ULONG)c1) { + do { + p++; + lo = *p; + ln = (lo + 1) & BN_MASK2; + *p = ln; + } while (ln == 0); + } + } +} + +/* + * n+tn is the word length t needs to be n*4 is size, as does r + */ /* tnX may not be negative but less than n */ void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n, - int tna, int tnb, BN_ULONG *t) - { - int i,j,n2=n*2; - int c1,c2,neg; - BN_ULONG ln,lo,*p; + int tna, int tnb, BN_ULONG *t) +{ + int i, j, n2 = n * 2; + int c1, c2, neg; + BN_ULONG ln, lo, *p; # ifdef BN_COUNT - fprintf(stderr," bn_mul_part_recursive (%d%+d) * (%d%+d)\n", - n, tna, n, tnb); + fprintf(stderr, " bn_mul_part_recursive (%d%+d) * (%d%+d)\n", + n, tna, n, tnb); # endif - if (n < 8) - { - bn_mul_normal(r,a,n+tna,b,n+tnb); - return; - } - - /* r=(a[0]-a[1])*(b[1]-b[0]) */ - c1=bn_cmp_part_words(a,&(a[n]),tna,n-tna); - c2=bn_cmp_part_words(&(b[n]),b,tnb,tnb-n); - neg=0; - switch (c1*3+c2) - { - case -4: - bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */ - bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */ - break; - case -3: - /* break; */ - case -2: - bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */ - bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); /* + */ - neg=1; - break; - case -1: - case 0: - case 1: - /* break; */ - case 2: - bn_sub_part_words(t, a, &(a[n]),tna,n-tna); /* + */ - bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */ - neg=1; - break; - case 3: - /* break; */ - case 4: - bn_sub_part_words(t, a, &(a[n]),tna,n-tna); - bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); - break; - } - /* The zero case isn't yet implemented here. The speedup - would probably be negligible. */ + if (n < 8) { + bn_mul_normal(r, a, n + tna, b, n + tnb); + return; + } + + /* r=(a[0]-a[1])*(b[1]-b[0]) */ + c1 = bn_cmp_part_words(a, &(a[n]), tna, n - tna); + c2 = bn_cmp_part_words(&(b[n]), b, tnb, tnb - n); + neg = 0; + switch (c1 * 3 + c2) { + case -4: + bn_sub_part_words(t, &(a[n]), a, tna, tna - n); /* - */ + bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb); /* - */ + break; + case -3: + /* break; */ + case -2: + bn_sub_part_words(t, &(a[n]), a, tna, tna - n); /* - */ + bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n); /* + */ + neg = 1; + break; + case -1: + case 0: + case 1: + /* break; */ + case 2: + bn_sub_part_words(t, a, &(a[n]), tna, n - tna); /* + */ + bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb); /* - */ + neg = 1; + break; + case 3: + /* break; */ + case 4: + bn_sub_part_words(t, a, &(a[n]), tna, n - tna); + bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n); + break; + } + /* + * The zero case isn't yet implemented here. The speedup would probably + * be negligible. + */ # if 0 - if (n == 4) - { - bn_mul_comba4(&(t[n2]),t,&(t[n])); - bn_mul_comba4(r,a,b); - bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn); - memset(&(r[n2+tn*2]),0,sizeof(BN_ULONG)*(n2-tn*2)); - } - else + if (n == 4) { + bn_mul_comba4(&(t[n2]), t, &(t[n])); + bn_mul_comba4(r, a, b); + bn_mul_normal(&(r[n2]), &(a[n]), tn, &(b[n]), tn); + memset(&(r[n2 + tn * 2]), 0, sizeof(BN_ULONG) * (n2 - tn * 2)); + } else # endif - if (n == 8) - { - bn_mul_comba8(&(t[n2]),t,&(t[n])); - bn_mul_comba8(r,a,b); - bn_mul_normal(&(r[n2]),&(a[n]),tna,&(b[n]),tnb); - memset(&(r[n2+tna+tnb]),0,sizeof(BN_ULONG)*(n2-tna-tnb)); - } - else - { - p= &(t[n2*2]); - bn_mul_recursive(&(t[n2]),t,&(t[n]),n,0,0,p); - bn_mul_recursive(r,a,b,n,0,0,p); - i=n/2; - /* If there is only a bottom half to the number, - * just do it */ - if (tna > tnb) - j = tna - i; - else - j = tnb - i; - if (j == 0) - { - bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]), - i,tna-i,tnb-i,p); - memset(&(r[n2+i*2]),0,sizeof(BN_ULONG)*(n2-i*2)); - } - else if (j > 0) /* eg, n == 16, i == 8 and tn == 11 */ - { - bn_mul_part_recursive(&(r[n2]),&(a[n]),&(b[n]), - i,tna-i,tnb-i,p); - memset(&(r[n2+tna+tnb]),0, - sizeof(BN_ULONG)*(n2-tna-tnb)); - } - else /* (j < 0) eg, n == 16, i == 8 and tn == 5 */ - { - memset(&(r[n2]),0,sizeof(BN_ULONG)*n2); - if (tna < BN_MUL_RECURSIVE_SIZE_NORMAL - && tnb < BN_MUL_RECURSIVE_SIZE_NORMAL) - { - bn_mul_normal(&(r[n2]),&(a[n]),tna,&(b[n]),tnb); - } - else - { - for (;;) - { - i/=2; - /* these simplified conditions work - * exclusively because difference - * between tna and tnb is 1 or 0 */ - if (i < tna || i < tnb) - { - bn_mul_part_recursive(&(r[n2]), - &(a[n]),&(b[n]), - i,tna-i,tnb-i,p); - break; - } - else if (i == tna || i == tnb) - { - bn_mul_recursive(&(r[n2]), - &(a[n]),&(b[n]), - i,tna-i,tnb-i,p); - break; - } - } |