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libmp: initial attempt at constant time code, faster reductions for special primes (for ecc)

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introduce MPtimesafe flag to request time invariant computation
disables normalization so significant digits are not leaked.
This commit is contained in:
cinap_lenrek 2015-11-21 09:39:59 +01:00
parent b677ab0c59
commit 38e1e5272f
32 changed files with 660 additions and 229 deletions
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21
sys/include/mp.h
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@ -22,7 +22,10 @@ struct mpint
enum
{
MPstatic= 0x01,
MPstatic= 0x01, /* static constant */
MPnorm= 0x02, /* normalization status */
MPtimesafe= 0x04, /* request time invariant computation */
Dbytes= sizeof(mpdigit), /* bytes per digit */
Dbits= Dbytes*8 /* bits per digit */
};
@ -32,7 +35,7 @@ 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* mpnorm(mpint *b); /* dump leading zeros */
mpint* mpcopy(mpint *b);
void mpassign(mpint *old, mpint *new);
@ -47,8 +50,10 @@ int mpfmt(Fmt*);
char* mptoa(mpint*, int, char*, int);
mpint* letomp(uchar*, uint, mpint*); /* byte array, little-endian */
int mptole(mpint*, uchar*, uint, uchar**);
void mptolel(mpint *b, uchar *p, int n);
mpint* betomp(uchar*, uint, mpint*); /* byte array, big-endian */
int mptobe(mpint*, uchar*, uint, uchar**);
void mptober(mpint *b, uchar *p, int n);
uint mptoui(mpint*); /* unsigned int */
mpint* uitomp(uint, mpint*);
int mptoi(mpint*); /* int */
@ -71,12 +76,20 @@ 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 */
/* modular arithmetic, time invariant when 0≤b1≤m-1 and 0≤b2≤m-1 */
void mpmodadd(mpint *b1, mpint *b2, mpint *m, mpint *sum); /* sum = b1+b2 % m */
void mpmodsub(mpint *b1, mpint *b2, mpint *m, mpint *diff); /* diff = b1-b2 % m */
void mpmodmul(mpint *b1, mpint *b2, mpint *m, mpint *prod); /* prod = b1*b2 % 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);
/* res = s != 0 ? b1 : b2 */
void mpsel(int s, mpint *b1, mpint *b2, mpint *res);
/* 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);
@ -106,12 +119,14 @@ void mpvecdigmuladd(mpdigit *b, int n, mpdigit m, mpdigit *p);
/* 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] */
/* 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);
void mpvectsmul(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);
int mpvectscmp(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 */