Subversion Repositories planix.SVN

#define _MPINT 1

// the code assumes mpdigit to be at least an int
// mpdigit must be an atomic type.  mpdigit is defined
// in the architecture specific u.h

typedef struct mpint mpint;

struct mpint
{
        int     sign;   // +1 or -1
        int     size;   // allocated digits
        int     top;    // significant digits
        mpdigit *p;
        char    flags;
};

enum
{
        MPstatic=       0x01,
        Dbytes=         sizeof(mpdigit),        // bytes per digit
        Dbits=          Dbytes*8                // bits per digit
};

// allocation
void    mpsetminbits(int n);    // newly created mpint's get at least n bits
mpint*  mpnew(int n);           // create a new mpint with at least n bits
void    mpfree(mpint *b);
void    mpbits(mpint *b, int n);        // ensure that b has at least n bits
void    mpnorm(mpint *b);               // dump leading zeros
mpint*  mpcopy(mpint *b);
void    mpassign(mpint *old, mpint *new);

// random bits
mpint*  mprand(int bits, void (*gen)(uchar*, int), mpint *b);

// conversion
mpint*  strtomp(char*, char**, int, mpint*);    // ascii
int     mpfmt(Fmt*);
char*   mptoa(mpint*, int, char*, int);
mpint*  letomp(uchar*, uint, mpint*);   // byte array, little-endian
int     mptole(mpint*, uchar*, uint, uchar**);
mpint*  betomp(uchar*, uint, mpint*);   // byte array, little-endian
int     mptobe(mpint*, uchar*, uint, uchar**);
uint    mptoui(mpint*);                 // unsigned int
mpint*  uitomp(uint, mpint*);
int     mptoi(mpint*);                  // int
mpint*  itomp(int, mpint*);
uvlong  mptouv(mpint*);                 // unsigned vlong
mpint*  uvtomp(uvlong, mpint*);
vlong   mptov(mpint*);                  // vlong
mpint*  vtomp(vlong, mpint*);

// divide 2 digits by one
void    mpdigdiv(mpdigit *dividend, mpdigit divisor, mpdigit *quotient);

// in the following, the result mpint may be
// the same as one of the inputs.
void    mpadd(mpint *b1, mpint *b2, mpint *sum);        // sum = b1+b2
void    mpsub(mpint *b1, mpint *b2, mpint *diff);       // diff = b1-b2
void    mpleft(mpint *b, int shift, mpint *res);        // res = b<<shift
void    mpright(mpint *b, int shift, mpint *res);       // res = b>>shift
void    mpmul(mpint *b1, mpint *b2, mpint *prod);       // prod = b1*b2
void    mpexp(mpint *b, mpint *e, mpint *m, mpint *res);        // res = b**e mod m
void    mpmod(mpint *b, mpint *m, mpint *remainder);    // remainder = b mod m

// quotient = dividend/divisor, remainder = dividend % divisor
void    mpdiv(mpint *dividend, mpint *divisor,  mpint *quotient, mpint *remainder);

// return neg, 0, pos as b1-b2 is neg, 0, pos
int     mpcmp(mpint *b1, mpint *b2);

// extended gcd return d, x, and y, s.t. d = gcd(a,b) and ax+by = d
void    mpextendedgcd(mpint *a, mpint *b, mpint *d, mpint *x, mpint *y);

// res = b**-1 mod m
void    mpinvert(mpint *b, mpint *m, mpint *res);

// bit counting
int     mpsignif(mpint*);       // number of sigificant bits in mantissa
int     mplowbits0(mpint*);     // k, where n = 2**k * q for odd q

// well known constants
extern mpint    *mpzero, *mpone, *mptwo;

// sum[0:alen] = a[0:alen-1] + b[0:blen-1]
// prereq: alen >= blen, sum has room for alen+1 digits
void    mpvecadd(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *sum);

// diff[0:alen-1] = a[0:alen-1] - b[0:blen-1]
// prereq: alen >= blen, diff has room for alen digits
void    mpvecsub(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *diff);

// p[0:n] += m * b[0:n-1]
// prereq: p has room for n+1 digits
void    mpvecdigmuladd(mpdigit *b, int n, mpdigit m, mpdigit *p);

// p[0:n] -= m * b[0:n-1]
// prereq: p has room for n+1 digits
int     mpvecdigmulsub(mpdigit *b, int n, mpdigit m, mpdigit *p);

// p[0:alen*blen-1] = a[0:alen-1] * b[0:blen-1]
// prereq: alen >= blen, p has room for m*n digits
void    mpvecmul(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *p);

// sign of a - b or zero if the same
int     mpveccmp(mpdigit *a, int alen, mpdigit *b, int blen);

// divide the 2 digit dividend by the one digit divisor and stick in quotient
// we assume that the result is one digit - overflow is all 1's
void    mpdigdiv(mpdigit *dividend, mpdigit divisor, mpdigit *quotient);

// playing with magnitudes
int     mpmagcmp(mpint *b1, mpint *b2);
void    mpmagadd(mpint *b1, mpint *b2, mpint *sum);     // sum = b1+b2
void    mpmagsub(mpint *b1, mpint *b2, mpint *sum);     // sum = b1+b2

// chinese remainder theorem
typedef struct CRTpre   CRTpre;         // precomputed values for converting
                                        //  twixt residues and mpint
typedef struct CRTres   CRTres;         // residue form of an mpint

struct CRTres
{
        int     n;              // number of residues
        mpint   *r[1];          // residues
};

CRTpre* crtpre(int, mpint**);                   // precompute conversion values
CRTres* crtin(CRTpre*, mpint*);                 // convert mpint to residues
void    crtout(CRTpre*, CRTres*, mpint*);       // convert residues to mpint
void    crtprefree(CRTpre*);
void    crtresfree(CRTres*);