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 /*
  68  * The giant stack package is a local cache which allows us to avoid calls
  69  * to malloc() for borrowGiant(). On a 90 Mhz Pentium, enabling the
  70  * giant stack package shows about a 1.35 speedup factor over an identical
  71  * CryptKit without the giant stacks enabled.
  72  */
  73 #define GIANTS_VIA_STACK        CRYPTKIT_GIANT_STACK_ENABLE
  74
  75 typedef struct {
  76          int sign;              /* number of giantDigits = abs(sign) */
  77      unsigned capacity;         /* largest possible number of giantDigits */
  78          giantDigit n[1];               /* n[0] is l.s. digit */
  79 } giantstruct;
  80 typedef giantstruct *giant;
  81
  82 #if             GIANTS_VIA_STACK
  83 /*
  84  * For giant stack debug only
  85  * Set default giant size (i.e., for newGiant(0) and borrowGiant(0))
  86  */
  87 void setGiantSize(unsigned numDigits);
  88
  89 /*
  90  * Initialize giant stacks, with up to specified max giant size.
  91  */
  92 void initGiantStacks(unsigned maxDigits);
  93
  94 /*
  95  * Free giant stacks on shutdown.
  96  */
  97 void freeGiantStacks(void);
  98
  99 #endif  /* GIANTS_VIA_STACK */
 100
 101 giant newGiant(unsigned numDigits);
 102 giant copyGiant(giant x);
 103 void freeGiant(giant x);
 104
 105 giant borrowGiant(unsigned numDigits);  /* get a temporary */
 106 void returnGiant(giant);                /* return it */
 107 unsigned bitlen(giant n);               /* Returns the bit-length n;
 108                                          * e.g. n=7 returns 3. */
 109 int bitval(giant n, int pos);           /* Returns the value of bit pos of n */
 110 int isZero(giant g);                    /* Returns whether g is zero */
 111 int isone(giant g);                     /* Returns whether g is 1 */
 112 void gtog(giant src, giant dest);       /* Copies one giant to another */
 113 void int_to_giant(int n, giant g);      /* Gives a giant an int value */
 114 int gcompg(giant a, giant b);           /* Returns 1, 0, -1 as a>b, a=b, a<b */
 115 void addg(giant a, giant b);            /* b += a */
 116 void iaddg(int a, giant b);             /* b += a */
 117 void subg(giant a, giant b);            /* b -= a. */
 118 void imulg(unsigned n, giant g);        /* g *= n */
 119 void negg(giant g);                     /* g := -g. */
 120 int binvg(giant n, giant x);            /* Same as invg(), but uses binary
 121                                          * division. */
 122 int binvaux(giant p, giant x);
 123 void gmersennemod(int n, giant g);      /* g := g (mod 2^n-1). */
 124 void gshiftleft(int bits, giant g);     /* Shift g left by bits, introducing
 125                                          * zeros on the right. */
 126 void gshiftright(int bits, giant g);    /* Shift g right by bits, losing bits
 127                                          * on the right. */
 128 void extractbits(unsigned n, giant src, giant dest);
 129                                         /* dest becomes lowermost n bits of
 130                                          * src.  Equivalent to
 131                                          * dest = src % 2^n */
 132
 133 void grammarSquare(giant a);            /* g *= g. */
 134 #define gsquare(g) grammarSquare(g)
 135
 136 void mulg(giant a, giant b);            /* b *= a. */
 137 int gsign(giant g);                     /* Returns the sign of g: -1, 0, 1. */
 138 void gtrimSign(giant g);                /* Adjust sign for possible leading
 139                                          * (m.s.) zero digits */
 140
 141 void divg(giant d, giant n);            /* n becomes |n|/d. n is arbitrary,
 142                                          * but the denominator d must be
 143                                          * positive! */
 144 int scompg(int n, giant g);
 145 void modg(giant den, giant num);        /* num := num mod den, any positive
 146                                          * den. */
 147 void clearGiant(giant g);               /* zero a giant's data */
 148
 149 /*
 150  * Optimized modg and divg, with routine to calculate necessary reciprocal
 151  */
 152 void make_recip(giant d, giant r);
 153 void divg_via_recip(giant denom, giant recip, giant numer);
 154                                         /* numer := |n|/d. */
 155 void modg_via_recip(giant denom, giant recip, giant numer);
 156                                         /* num := num mod den */
 157
 158 #ifdef __cplusplus
 159 }
 160 #endif
 161
 162 #endif  /* _CK_NSGIANTINTS_H_ */