OSX/libsecurity_cryptkit/lib/giantIntegers.h

   1 /* Copyright (c) 1998,2011-2012,2014 Apple Inc.  All Rights Reserved.
   2  *
   3  * NOTICE: USE OF THE MATERIALS ACCOMPANYING THIS NOTICE IS SUBJECT
   4  * TO THE TERMS OF THE SIGNED "FAST ELLIPTIC ENCRYPTION (FEE) REFERENCE
   5  * SOURCE CODE EVALUATION AGREEMENT" BETWEEN APPLE, INC. AND THE
   6  * ORIGINAL LICENSEE THAT OBTAINED THESE MATERIALS FROM APPLE,
   7  * INC.  ANY USE OF THESE MATERIALS NOT PERMITTED BY SUCH AGREEMENT WILL
   8  * EXPOSE YOU TO LIABILITY.
   9  ***************************************************************************
  10  *
  11  * giantIntegers.h - large-integer arithmetic library.
  12  *
  13  * Revision History
  14  * ----------------
  15  * 05 Oct 98 at Apple
  16  *      Default "unsigned int" giantDigit for __i386__ and __i486__
  17  * 08 May 97 at Apple
  18  *      Changed size of giantstruct.n to 1 for Mac build
  19  *      Created.
  20  */
  21
  22 #ifndef _CK_NSGIANTINTS_H_
  23 #define _CK_NSGIANTINTS_H_
  24
  25 #include <security_cryptkit/ckconfig.h>
  26
  27 #ifdef __cplusplus
  28 extern "C" {
  29 #endif
  30
  31 /*
  32  * Size of giant digit.
  33  */
  34 #if     NeXT || __i386__ || __i486__ || __x86_64__
  35
  36 typedef unsigned int giantDigit;
  37
  38 /*
  39  * used to divide by GIANT_BITS_PER_DIGIT via shift - no easy way to get
  40  * the compiler to calculate this.
  41  */
  42 #define GIANT_LOG2_BITS_PER_DIGIT 5
  43
  44 #elif defined(macintosh) || defined(__ppc__)
  45
  46 typedef unsigned int giantDigit;
  47 #define GIANT_LOG2_BITS_PER_DIGIT       5
  48
  49 #else
  50
  51 typedef unsigned short giantDigit;
  52 #define GIANT_LOG2_BITS_PER_DIGIT       4
  53
  54 #endif
  55
  56 /* platform-independent digit manipulation macros */
  57
  58 #define GIANT_BYTES_PER_DIGIT   (sizeof(giantDigit))
  59 #define GIANT_BITS_PER_DIGIT    (8 * GIANT_BYTES_PER_DIGIT)
  60 #define GIANT_DIGIT_MASK        ((giantDigit)~0)
  61 #define BYTES_TO_GIANT_DIGITS(x)        \
  62         ((x + GIANT_BYTES_PER_DIGIT - 1) / GIANT_BYTES_PER_DIGIT)
  63
  64 #define MAX_DIGITS ((1<<18)+(1<<17))
  65                         /* 2^(16*MAX_DIGITS)-1 will fit into a giant. */
  66
  67 typedef struct {
  68          int sign;              /* number of giantDigits = abs(sign) */
  69      unsigned capacity;         /* largest possible number of giantDigits */
  70          giantDigit n[1];               /* n[0] is l.s. digit */
  71 } giantstruct;
  72 typedef giantstruct *giant;
  73
  74 giant newGiant(unsigned numDigits);
  75 giant copyGiant(giant x);
  76 void freeGiant(giant x);
  77
  78 giant borrowGiant(unsigned numDigits);  /* get a temporary */
  79 void returnGiant(giant);                /* return it */
  80 unsigned bitlen(giant n);               /* Returns the bit-length n;
  81                                          * e.g. n=7 returns 3. */
  82 int bitval(giant n, int pos);           /* Returns the value of bit pos of n */
  83 int isZero(giant g);                    /* Returns whether g is zero */
  84 int isone(giant g);                     /* Returns whether g is 1 */
  85 void gtog(giant src, giant dest);       /* Copies one giant to another */
  86 void int_to_giant(int n, giant g);      /* Gives a giant an int value */
  87 int gcompg(giant a, giant b);           /* Returns 1, 0, -1 as a>b, a=b, a<b */
  88 void addg(giant a, giant b);            /* b += a */
  89 void iaddg(int a, giant b);             /* b += a */
  90 void subg(giant a, giant b);            /* b -= a. */
  91 void imulg(unsigned n, giant g);        /* g *= n */
  92 void negg(giant g);                     /* g := -g. */
  93 int binvg(giant n, giant x);            /* Same as invg(), but uses binary
  94                                          * division. */
  95 int binvaux(giant p, giant x);
  96 void gmersennemod(int n, giant g);      /* g := g (mod 2^n-1). */
  97 void gshiftleft(int bits, giant g);     /* Shift g left by bits, introducing
  98                                          * zeros on the right. */
  99 void gshiftright(int bits, giant g);    /* Shift g right by bits, losing bits
 100                                          * on the right. */
 101 void extractbits(unsigned n, giant src, giant dest);
 102                                         /* dest becomes lowermost n bits of
 103                                          * src.  Equivalent to
 104                                          * dest = src % 2^n */
 105
 106 void grammarSquare(giant a);            /* g *= g. */
 107 #define gsquare(g) grammarSquare(g)
 108
 109 void mulg(giant a, giant b);            /* b *= a. */
 110 int gsign(giant g);                     /* Returns the sign of g: -1, 0, 1. */
 111 void gtrimSign(giant g);                /* Adjust sign for possible leading
 112                                          * (m.s.) zero digits */
 113
 114 void divg(giant d, giant n);            /* n becomes |n|/d. n is arbitrary,
 115                                          * but the denominator d must be
 116                                          * positive! */
 117 int scompg(int n, giant g);
 118 void modg(giant den, giant num);        /* num := num mod den, any positive
 119                                          * den. */
 120 void clearGiant(giant g);               /* zero a giant's data */
 121
 122 /*
 123  * Optimized modg and divg, with routine to calculate necessary reciprocal
 124  */
 125 void make_recip(giant d, giant r);
 126 void divg_via_recip(giant denom, giant recip, giant numer);
 127                                         /* numer := |n|/d. */
 128 void modg_via_recip(giant denom, giant recip, giant numer);
 129                                         /* num := num mod den */
 130
 131 #ifdef __cplusplus
 132 }
 133 #endif
 134
 135 #endif  /* _CK_NSGIANTINTS_H_ */