/*
* Burn the evidence, just in case.
*/
- memset(b, 0, sizeof(b[0]) * (b[0] + 1));
+ smemclr(b, sizeof(b[0]) * (b[0] + 1));
sfree(b);
}
for (cp = cps, bp = b + len; cp--, bp-- > b ;) {
t = (MUL_WORD(*ap, *bp) + carry) + *cp;
*cp = (BignumInt) t;
- carry = t >> BIGNUM_INT_BITS;
+ carry = (BignumInt)(t >> BIGNUM_INT_BITS);
}
*cp = carry;
}
for (cp = cps, bp = b + len; bp--, cp-- > c ;) {
t = (MUL_WORD(*ap, *bp) + carry) + *cp;
*cp = (BignumInt) t;
- carry = t >> BIGNUM_INT_BITS;
+ carry = (BignumInt)(t >> BIGNUM_INT_BITS);
}
}
}
int i, k;
m0 = m[0];
+ assert(m0 >> (BIGNUM_INT_BITS-1) == 1);
if (mlen > 1)
m1 = m[1];
else
result[0]--;
/* Free temporary arrays */
- for (i = 0; i < 2 * mlen; i++)
- a[i] = 0;
+ smemclr(a, 2 * mlen * sizeof(*a));
sfree(a);
- for (i = 0; i < scratchlen; i++)
- scratch[i] = 0;
+ smemclr(scratch, scratchlen * sizeof(*scratch));
sfree(scratch);
- for (i = 0; i < 2 * mlen; i++)
- b[i] = 0;
+ smemclr(b, 2 * mlen * sizeof(*b));
sfree(b);
- for (i = 0; i < mlen; i++)
- m[i] = 0;
+ smemclr(m, mlen * sizeof(*m));
sfree(m);
- for (i = 0; i < mlen; i++)
- n[i] = 0;
+ smemclr(n, mlen * sizeof(*n));
sfree(n);
freebn(base);
len = mod[0];
r = bn_power_2(BIGNUM_INT_BITS * len);
inv = modinv(mod, r);
+ assert(inv); /* cannot fail, since mod is odd and r is a power of 2 */
/*
* Multiply the base by r mod n, to get it into Montgomery
mninv = snewn(len, BignumInt);
for (j = 0; j < len; j++)
- mninv[len - 1 - j] = (j < inv[0] ? inv[j + 1] : 0);
+ mninv[len - 1 - j] = (j < (int)inv[0] ? inv[j + 1] : 0);
freebn(inv); /* we don't need this copy of it any more */
/* Now negate mninv mod r, so it's the inverse of -n rather than +n. */
x = snewn(len, BignumInt);
/* x = snewn(len, BignumInt); */ /* already done above */
for (j = 0; j < len; j++)
- x[len - 1 - j] = (j < base[0] ? base[j + 1] : 0);
+ x[len - 1 - j] = (j < (int)base[0] ? base[j + 1] : 0);
freebn(base); /* we don't need this copy of it any more */
a = snewn(2*len, BignumInt);
b = snewn(2*len, BignumInt);
for (j = 0; j < len; j++)
- a[2*len - 1 - j] = (j < rn[0] ? rn[j + 1] : 0);
+ a[2*len - 1 - j] = (j < (int)rn[0] ? rn[j + 1] : 0);
freebn(rn);
/* Scratch space for multiplies */
result[0]--;
/* Free temporary arrays */
- for (i = 0; i < scratchlen; i++)
- scratch[i] = 0;
+ smemclr(scratch, scratchlen * sizeof(*scratch));
sfree(scratch);
- for (i = 0; i < 2 * len; i++)
- a[i] = 0;
+ smemclr(a, 2 * len * sizeof(*a));
sfree(a);
- for (i = 0; i < 2 * len; i++)
- b[i] = 0;
+ smemclr(b, 2 * len * sizeof(*b));
sfree(b);
- for (i = 0; i < len; i++)
- mninv[i] = 0;
+ smemclr(mninv, len * sizeof(*mninv));
sfree(mninv);
- for (i = 0; i < len; i++)
- n[i] = 0;
+ smemclr(n, len * sizeof(*n));
sfree(n);
- for (i = 0; i < len; i++)
- x[i] = 0;
+ smemclr(x, len * sizeof(*x));
sfree(x);
return result;
int pqlen, mlen, rlen, i, j;
Bignum result;
+ /*
+ * The most significant word of mod needs to be non-zero. It
+ * should already be, but let's make sure.
+ */
+ assert(mod[mod[0]] != 0);
+
/* Allocate m of size mlen, copy mod to m */
/* We use big endian internally */
mlen = mod[0];
pqlen = (p[0] > q[0] ? p[0] : q[0]);
+ /*
+ * Make sure that we're allowing enough space. The shifting below
+ * will underflow the vectors we allocate if pqlen is too small.
+ */
+ if (2*pqlen <= mlen)
+ pqlen = mlen/2 + 1;
+
/* Allocate n of size pqlen, copy p to n */
n = snewn(pqlen, BignumInt);
i = pqlen - p[0];
result[0]--;
/* Free temporary arrays */
- for (i = 0; i < scratchlen; i++)
- scratch[i] = 0;
+ smemclr(scratch, scratchlen * sizeof(*scratch));
sfree(scratch);
- for (i = 0; i < 2 * pqlen; i++)
- a[i] = 0;
+ smemclr(a, 2 * pqlen * sizeof(*a));
sfree(a);
- for (i = 0; i < mlen; i++)
- m[i] = 0;
+ smemclr(m, mlen * sizeof(*m));
sfree(m);
- for (i = 0; i < pqlen; i++)
- n[i] = 0;
+ smemclr(n, pqlen * sizeof(*n));
sfree(n);
- for (i = 0; i < pqlen; i++)
- o[i] = 0;
+ smemclr(o, pqlen * sizeof(*o));
sfree(o);
return result;
int mshift;
int plen, mlen, i, j;
+ /*
+ * The most significant word of mod needs to be non-zero. It
+ * should already be, but let's make sure.
+ */
+ assert(mod[mod[0]] != 0);
+
/* Allocate m of size mlen, copy mod to m */
/* We use big endian internally */
mlen = mod[0];
}
/* Free temporary arrays */
- for (i = 0; i < mlen; i++)
- m[i] = 0;
+ smemclr(m, mlen * sizeof(*m));
sfree(m);
- for (i = 0; i < plen; i++)
- n[i] = 0;
+ smemclr(n, plen * sizeof(*n));
sfree(n);
}
}
ret[0] = maxspot;
- for (i = 0; i < wslen; i++)
- workspace[i] = 0;
+ smemclr(workspace, wslen * sizeof(*workspace));
sfree(workspace);
return ret;
}
Bignum x = copybn(One);
int sign = +1;
+ assert(number[number[0]] != 0);
+ assert(modulus[modulus[0]] != 0);
+
while (bignum_cmp(b, One) != 0) {
- Bignum t = newbn(b[0]);
- Bignum q = newbn(a[0]);
+ Bignum t, q;
+
+ if (bignum_cmp(b, Zero) == 0) {
+ /*
+ * Found a common factor between the inputs, so we cannot
+ * return a modular inverse at all.
+ */
+ freebn(b);
+ freebn(a);
+ freebn(xp);
+ freebn(x);
+ return NULL;
+ }
+
+ t = newbn(b[0]);
+ q = newbn(a[0]);
bigdivmod(a, b, t, q);
while (t[0] > 1 && t[t[0]] == 0)
t[0]--;
/*
* Done.
*/
+ smemclr(workspace, x[0] * sizeof(*workspace));
sfree(workspace);
return ret;
}
#include <ctype.h>
/*
- * gcc -g -O0 -DTESTBN -o testbn sshbn.c misc.c -I unix -I charset
+ * gcc -Wall -g -O0 -DTESTBN -o testbn sshbn.c misc.c conf.c tree234.c unix/uxmisc.c -I. -I unix -I charset
*
* Then feed to this program's standard input the output of
* testdata/bignum.py .
Bignum a, b, c, p;
if (ptrnum != 3) {
- printf("%d: mul with %d parameters, expected 3\n", line);
+ printf("%d: mul with %d parameters, expected 3\n", line, ptrnum);
exit(1);
}
a = bignum_from_bytes(ptrs[0], ptrs[1]-ptrs[0]);
freebn(b);
freebn(c);
freebn(p);
+ } else if (!strcmp(buf, "modmul")) {
+ Bignum a, b, m, c, p;
+
+ if (ptrnum != 4) {
+ printf("%d: modmul with %d parameters, expected 4\n",
+ line, ptrnum);
+ exit(1);
+ }
+ a = bignum_from_bytes(ptrs[0], ptrs[1]-ptrs[0]);
+ b = bignum_from_bytes(ptrs[1], ptrs[2]-ptrs[1]);
+ m = bignum_from_bytes(ptrs[2], ptrs[3]-ptrs[2]);
+ c = bignum_from_bytes(ptrs[3], ptrs[4]-ptrs[3]);
+ p = modmul(a, b, m);
+
+ if (bignum_cmp(c, p) == 0) {
+ passes++;
+ } else {
+ char *as = bignum_decimal(a);
+ char *bs = bignum_decimal(b);
+ char *ms = bignum_decimal(m);
+ char *cs = bignum_decimal(c);
+ char *ps = bignum_decimal(p);
+
+ printf("%d: fail: %s * %s mod %s gave %s expected %s\n",
+ line, as, bs, ms, ps, cs);
+ fails++;
+
+ sfree(as);
+ sfree(bs);
+ sfree(ms);
+ sfree(cs);
+ sfree(ps);
+ }
+ freebn(a);
+ freebn(b);
+ freebn(m);
+ freebn(c);
+ freebn(p);
} else if (!strcmp(buf, "pow")) {
Bignum base, expt, modulus, expected, answer;
if (ptrnum != 4) {
- printf("%d: mul with %d parameters, expected 3\n", line);
+ printf("%d: mul with %d parameters, expected 4\n", line, ptrnum);
exit(1);
}