#include <stdlib.h>
#include <string.h>
#include <limits.h>
+#include <ctype.h>
#include "misc.h"
-/*
- * Usage notes:
- * * Do not call the DIVMOD_WORD macro with expressions such as array
- * subscripts, as some implementations object to this (see below).
- * * Note that none of the division methods below will cope if the
- * quotient won't fit into BIGNUM_INT_BITS. Callers should be careful
- * to avoid this case.
- * If this condition occurs, in the case of the x86 DIV instruction,
- * an overflow exception will occur, which (according to a correspondent)
- * will manifest on Windows as something like
- * 0xC0000095: Integer overflow
- * The C variant won't give the right answer, either.
- */
-
-#if defined __GNUC__ && defined __i386__
-typedef unsigned long BignumInt;
-typedef unsigned long long BignumDblInt;
-#define BIGNUM_INT_MASK 0xFFFFFFFFUL
-#define BIGNUM_TOP_BIT 0x80000000UL
-#define BIGNUM_INT_BITS 32
-#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2)
-#define DIVMOD_WORD(q, r, hi, lo, w) \
- __asm__("div %2" : \
- "=d" (r), "=a" (q) : \
- "r" (w), "d" (hi), "a" (lo))
-#elif defined _MSC_VER && defined _M_IX86
-typedef unsigned __int32 BignumInt;
-typedef unsigned __int64 BignumDblInt;
-#define BIGNUM_INT_MASK 0xFFFFFFFFUL
-#define BIGNUM_TOP_BIT 0x80000000UL
-#define BIGNUM_INT_BITS 32
-#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2)
-/* Note: MASM interprets array subscripts in the macro arguments as
- * assembler syntax, which gives the wrong answer. Don't supply them.
- * <http://msdn2.microsoft.com/en-us/library/bf1dw62z.aspx> */
-#define DIVMOD_WORD(q, r, hi, lo, w) do { \
- __asm mov edx, hi \
- __asm mov eax, lo \
- __asm div w \
- __asm mov r, edx \
- __asm mov q, eax \
-} while(0)
-#elif defined _LP64
-/* 64-bit architectures can do 32x32->64 chunks at a time */
-typedef unsigned int BignumInt;
-typedef unsigned long BignumDblInt;
-#define BIGNUM_INT_MASK 0xFFFFFFFFU
-#define BIGNUM_TOP_BIT 0x80000000U
-#define BIGNUM_INT_BITS 32
-#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2)
-#define DIVMOD_WORD(q, r, hi, lo, w) do { \
- BignumDblInt n = (((BignumDblInt)hi) << BIGNUM_INT_BITS) | lo; \
- q = n / w; \
- r = n % w; \
-} while (0)
-#elif defined _LLP64
-/* 64-bit architectures in which unsigned long is 32 bits, not 64 */
-typedef unsigned long BignumInt;
-typedef unsigned long long BignumDblInt;
-#define BIGNUM_INT_MASK 0xFFFFFFFFUL
-#define BIGNUM_TOP_BIT 0x80000000UL
-#define BIGNUM_INT_BITS 32
-#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2)
-#define DIVMOD_WORD(q, r, hi, lo, w) do { \
- BignumDblInt n = (((BignumDblInt)hi) << BIGNUM_INT_BITS) | lo; \
- q = n / w; \
- r = n % w; \
-} while (0)
-#else
-/* Fallback for all other cases */
-typedef unsigned short BignumInt;
-typedef unsigned long BignumDblInt;
-#define BIGNUM_INT_MASK 0xFFFFU
-#define BIGNUM_TOP_BIT 0x8000U
-#define BIGNUM_INT_BITS 16
-#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2)
-#define DIVMOD_WORD(q, r, hi, lo, w) do { \
- BignumDblInt n = (((BignumDblInt)hi) << BIGNUM_INT_BITS) | lo; \
- q = n / w; \
- r = n % w; \
-} while (0)
-#endif
-
-#define BIGNUM_INT_BYTES (BIGNUM_INT_BITS / 8)
+#include "sshbn.h"
#define BIGNUM_INTERNAL
typedef BignumInt *Bignum;
BignumInt bnZero[1] = { 0 };
BignumInt bnOne[2] = { 1, 1 };
+BignumInt bnTen[2] = { 1, 10 };
/*
* The Bignum format is an array of `BignumInt'. The first
* nonzero.
*/
-Bignum Zero = bnZero, One = bnOne;
+Bignum Zero = bnZero, One = bnOne, Ten = bnTen;
static Bignum newbn(int length)
{
assert(length >= 0 && length < INT_MAX / BIGNUM_INT_BITS);
b = snewn(length + 1, BignumInt);
- if (!b)
- abort(); /* FIXME */
memset(b, 0, (length + 1) * sizeof(*b));
b[0] = length;
return b;
}
static void internal_add_shifted(BignumInt *number,
- unsigned n, int shift)
+ BignumInt n, int shift)
{
int word = 1 + (shift / BIGNUM_INT_BITS);
int bshift = shift % BIGNUM_INT_BITS;
BignumInt *m, int mlen,
BignumInt *quot, int qshift)
{
- BignumInt m0, m1;
- unsigned int h;
+ BignumInt m0, m1, h;
int i, k;
m0 = m[0];
for (i = 0; i <= alen - mlen; i++) {
BignumDblInt t;
- unsigned int q, r, c, ai1;
+ BignumInt q, r, c, ai1;
if (i == 0) {
h = 0;
for (k = mlen - 1; k >= 0; k--) {
t = MUL_WORD(q, m[k]);
t += c;
- c = (unsigned)(t >> BIGNUM_INT_BITS);
+ c = (BignumInt)(t >> BIGNUM_INT_BITS);
if ((BignumInt) t > a[i + k])
c++;
a[i + k] -= (BignumInt) t;
/* Skip leading zero bits of exp. */
i = 0;
j = BIGNUM_INT_BITS-1;
- while (i < (int)exp[0] && (exp[exp[0] - i] & (1 << j)) == 0) {
+ while (i < (int)exp[0] && (exp[exp[0] - i] & ((BignumInt)1 << j)) == 0) {
j--;
if (j < 0) {
i++;
while (j >= 0) {
internal_mul(a + mlen, a + mlen, b, mlen, scratch);
internal_mod(b, mlen * 2, m, mlen, NULL, 0);
- if ((exp[exp[0] - i] & (1 << j)) != 0) {
+ if ((exp[exp[0] - i] & ((BignumInt)1 << j)) != 0) {
internal_mul(b + mlen, n, a, mlen, scratch);
internal_mod(a, mlen * 2, m, mlen, NULL, 0);
} else {
/* Skip leading zero bits of exp. */
i = 0;
j = BIGNUM_INT_BITS-1;
- while (i < (int)exp[0] && (exp[exp[0] - i] & (1 << j)) == 0) {
+ while (i < (int)exp[0] && (exp[exp[0] - i] & ((BignumInt)1 << j)) == 0) {
j--;
if (j < 0) {
i++;
while (j >= 0) {
internal_mul(a + len, a + len, b, len, scratch);
monty_reduce(b, n, mninv, scratch, len);
- if ((exp[exp[0] - i] & (1 << j)) != 0) {
+ if ((exp[exp[0] - i] & ((BignumInt)1 << j)) != 0) {
internal_mul(b + len, x, a, len, scratch);
monty_reduce(a, n, mninv, scratch, len);
} else {
/* Handle going round the corner of the modulus without having
* negative support in Bignum */
Bignum tmp = bigsub(n, b1);
- if (tmp) {
- ret = bigadd(tmp, a1);
- freebn(tmp);
- } else {
- ret = NULL;
- }
+ assert(tmp);
+ ret = bigadd(tmp, a1);
+ freebn(tmp);
}
if (a != a1) freebn(a1);
result[i] = 0;
for (i = nbytes; i--;) {
unsigned char byte = *data++;
- result[1 + i / BIGNUM_INT_BYTES] |= byte << (8*i % BIGNUM_INT_BITS);
+ result[1 + i / BIGNUM_INT_BYTES] |=
+ (BignumInt)byte << (8*i % BIGNUM_INT_BITS);
}
while (result[0] > 1 && result[result[0]] == 0)
return result;
}
+Bignum bignum_from_bytes_le(const unsigned char *data, int nbytes)
+{
+ Bignum result;
+ int w, i;
+
+ assert(nbytes >= 0 && nbytes < INT_MAX/8);
+
+ w = (nbytes + BIGNUM_INT_BYTES - 1) / BIGNUM_INT_BYTES; /* bytes->words */
+
+ result = newbn(w);
+ for (i = 1; i <= w; i++)
+ result[i] = 0;
+ for (i = 0; i < nbytes; ++i) {
+ unsigned char byte = *data++;
+ result[1 + i / BIGNUM_INT_BYTES] |=
+ (BignumInt)byte << (8*i % BIGNUM_INT_BITS);
+ }
+
+ while (result[0] > 1 && result[result[0]] == 0)
+ result[0]--;
+ return result;
+}
+
+Bignum bignum_from_decimal(const char *decimal)
+{
+ Bignum result = copybn(Zero);
+
+ while (*decimal) {
+ Bignum tmp, tmp2;
+
+ if (!isdigit((unsigned char)*decimal)) {
+ freebn(result);
+ return 0;
+ }
+
+ tmp = bigmul(result, Ten);
+ tmp2 = bignum_from_long(*decimal - '0');
+ result = bigadd(tmp, tmp2);
+ freebn(tmp);
+ freebn(tmp2);
+
+ decimal++;
+ }
+
+ return result;
+}
+
Bignum bignum_random_in_range(const Bignum lower, const Bignum upper)
{
Bignum ret = NULL;
+ unsigned char *bytes;
int upper_len = bignum_bitcount(upper);
int upper_bytes = upper_len / 8;
int upper_bits = upper_len % 8;
if (upper_bits) ++upper_bytes;
+ bytes = snewn(upper_bytes, unsigned char);
do {
- unsigned char *bytes;
int i;
if (ret) freebn(ret);
- bytes = snewn(upper_bytes, unsigned char);
for (i = 0; i < upper_bytes; ++i)
{
bytes[i] = (unsigned char)random_byte();
ret = bignum_from_bytes(bytes, upper_bytes);
} while (bignum_cmp(ret, lower) < 0 || bignum_cmp(ret, upper) > 0);
+ smemclr(bytes, upper_bytes);
+ sfree(bytes);
return ret;
}
abort(); /* beyond the end */
else {
int v = bitnum / BIGNUM_INT_BITS + 1;
- int mask = 1 << (bitnum % BIGNUM_INT_BITS);
+ BignumInt mask = (BignumInt)1 << (bitnum % BIGNUM_INT_BITS);
if (value)
bn[v] |= mask;
else
bits = bignum_bitcount(a) + shift;
ret = newbn((bits + BIGNUM_INT_BITS - 1) / BIGNUM_INT_BITS);
- if (!ret) return NULL;
shiftWords = shift / BIGNUM_INT_BITS;
shiftBits = shift % BIGNUM_INT_BITS;
* testdata/bignum.py .
*/
-void modalfatalbox(char *p, ...)
+void modalfatalbox(const char *p, ...)
{
va_list ap;
fprintf(stderr, "FATAL ERROR: ");
exit(1);
}
+int random_byte(void)
+{
+ modalfatalbox("random_byte called in testbn");
+ return 0;
+}
+
#define fromxdigit(c) ( (c)>'9' ? ((c)&0xDF) - 'A' + 10 : (c) - '0' )
int main(int argc, char **argv)
projects / PuTTY.git / blobdiff