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Added framework to sshbn.c to make it possible to vary the

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underlying integer type forming the Bignum. Using this, arranged
that gcc/x86 uses 32-bit chunks rather than the guaranteed ANSI-
portable 16-bit chunks. This has gained another 30% on key exchanges
by my measurements, but I'm not yet convinced that it's all
perfectly robust - it seems to work fine for SSH1 and SSH2/RSA but
I haven't ensured that every bignum routine is actually being
tested, so it may yet show up problems in DSA or key generation.

[originally from svn r3135]
This commit is contained in:
Simon Tatham 2003-04-23 14:48:57 +00:00
parent 041dcfd83d
commit afd4b4d662
2 changed files with 142 additions and 126 deletions
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4
ssh.h
View File

@ -315,6 +315,10 @@ Bignum bignum_rshift(Bignum number, int shift);
int bignum_cmp(Bignum a, Bignum b); int bignum_cmp(Bignum a, Bignum b);
char *bignum_decimal(Bignum x); char *bignum_decimal(Bignum x);
#ifdef DEBUG
void diagbn(char *prefix, Bignum md);
#endif
void *dh_setup_group1(void); void *dh_setup_group1(void);
void *dh_setup_group(Bignum pval, Bignum gval); void *dh_setup_group(Bignum pval, Bignum gval);
void dh_cleanup(void *); void dh_cleanup(void *);

264
sshbn.c
View File

@ -8,18 +8,36 @@
#include "misc.h" #include "misc.h"
#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)
#else
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)
#endif
#define BIGNUM_INT_BYTES (BIGNUM_INT_BITS / 8)
#define BIGNUM_INTERNAL #define BIGNUM_INTERNAL
typedef unsigned short *Bignum; typedef BignumInt *Bignum;
#include "ssh.h" #include "ssh.h"
unsigned short bnZero[1] = { 0 }; BignumInt bnZero[1] = { 0 };
unsigned short bnOne[2] = { 1, 1 }; BignumInt bnOne[2] = { 1, 1 };
/* /*
* The Bignum format is an array of `unsigned short'. The first * The Bignum format is an array of `BignumInt'. The first
* element of the array counts the remaining elements. The * element of the array counts the remaining elements. The
* remaining elements express the actual number, base 2^16, _least_ * remaining elements express the actual number, base 2^BIGNUM_INT_BITS, _least_
* significant digit first. (So it's trivial to extract the bit * significant digit first. (So it's trivial to extract the bit
* with value 2^n for any n.) * with value 2^n for any n.)
* *
@ -34,7 +52,7 @@ Bignum Zero = bnZero, One = bnOne;
static Bignum newbn(int length) static Bignum newbn(int length)
{ {
Bignum b = snewn(length + 1, unsigned short); Bignum b = snewn(length + 1, BignumInt);
if (!b) if (!b)
abort(); /* FIXME */ abort(); /* FIXME */
memset(b, 0, (length + 1) * sizeof(*b)); memset(b, 0, (length + 1) * sizeof(*b));
@ -50,7 +68,7 @@ void bn_restore_invariant(Bignum b)
Bignum copybn(Bignum orig) Bignum copybn(Bignum orig)
{ {
Bignum b = snewn(orig[0] + 1, unsigned short); Bignum b = snewn(orig[0] + 1, BignumInt);
if (!b) if (!b)
abort(); /* FIXME */ abort(); /* FIXME */
memcpy(b, orig, (orig[0] + 1) * sizeof(*b)); memcpy(b, orig, (orig[0] + 1) * sizeof(*b));
@ -68,7 +86,7 @@ void freebn(Bignum b)
Bignum bn_power_2(int n) Bignum bn_power_2(int n)
{ {
Bignum ret = newbn(n / 16 + 1); Bignum ret = newbn(n / BIGNUM_INT_BITS + 1);
bignum_set_bit(ret, n, 1); bignum_set_bit(ret, n, 1);
return ret; return ret;
} }
@ -78,41 +96,40 @@ Bignum bn_power_2(int n)
* Input is in the first len words of a and b. * Input is in the first len words of a and b.
* Result is returned in the first 2*len words of c. * Result is returned in the first 2*len words of c.
*/ */
static void internal_mul(unsigned short *a, unsigned short *b, static void internal_mul(BignumInt *a, BignumInt *b,
unsigned short *c, int len) BignumInt *c, int len)
{ {
int i, j; int i, j;
unsigned long ai, t; BignumDblInt t;
for (j = 0; j < 2 * len; j++) for (j = 0; j < 2 * len; j++)
c[j] = 0; c[j] = 0;
for (i = len - 1; i >= 0; i--) { for (i = len - 1; i >= 0; i--) {
ai = a[i];
t = 0; t = 0;
for (j = len - 1; j >= 0; j--) { for (j = len - 1; j >= 0; j--) {
t += ai * (unsigned long) b[j]; t += MUL_WORD(a[i], (BignumDblInt) b[j]);
t += (unsigned long) c[i + j + 1]; t += (BignumDblInt) c[i + j + 1];
c[i + j + 1] = (unsigned short) t; c[i + j + 1] = (BignumInt) t;
t = t >> 16; t = t >> BIGNUM_INT_BITS;
} }
c[i] = (unsigned short) t; c[i] = (BignumInt) t;
} }
} }
static void internal_add_shifted(unsigned short *number, static void internal_add_shifted(BignumInt *number,
unsigned n, int shift) unsigned n, int shift)
{ {
int word = 1 + (shift / 16); int word = 1 + (shift / BIGNUM_INT_BITS);
int bshift = shift % 16; int bshift = shift % BIGNUM_INT_BITS;
unsigned long addend; BignumDblInt addend;
addend = n << bshift; addend = n << bshift;
while (addend) { while (addend) {
addend += number[word]; addend += number[word];
number[word] = (unsigned short) addend & 0xFFFF; number[word] = (BignumInt) addend & BIGNUM_INT_MASK;
addend >>= 16; addend >>= BIGNUM_INT_BITS;
word++; word++;
} }
} }
@ -127,11 +144,11 @@ static void internal_add_shifted(unsigned short *number,
* rather than the internal bigendian format. Quotient parts are shifted * rather than the internal bigendian format. Quotient parts are shifted
* left by `qshift' before adding into quot. * left by `qshift' before adding into quot.
*/ */
static void internal_mod(unsigned short *a, int alen, static void internal_mod(BignumInt *a, int alen,
unsigned short *m, int mlen, BignumInt *m, int mlen,
unsigned short *quot, int qshift) BignumInt *quot, int qshift)
{ {
unsigned short m0, m1; BignumInt m0, m1;
unsigned int h; unsigned int h;
int i, k; int i, k;
@ -142,7 +159,7 @@ static void internal_mod(unsigned short *a, int alen,
m1 = 0; m1 = 0;
for (i = 0; i <= alen - mlen; i++) { for (i = 0; i <= alen - mlen; i++) {
unsigned long t; BignumDblInt t;
unsigned int q, r, c, ai1; unsigned int q, r, c, ai1;
if (i == 0) { if (i == 0) {
@ -158,30 +175,30 @@ static void internal_mod(unsigned short *a, int alen,
ai1 = a[i + 1]; ai1 = a[i + 1];
/* Find q = h:a[i] / m0 */ /* Find q = h:a[i] / m0 */
t = ((unsigned long) h << 16) + a[i]; t = ((BignumDblInt) h << BIGNUM_INT_BITS) + a[i];
q = t / m0; q = t / m0;
r = t % m0; r = t % m0;
/* Refine our estimate of q by looking at /* Refine our estimate of q by looking at
h:a[i]:a[i+1] / m0:m1 */ h:a[i]:a[i+1] / m0:m1 */
t = (long) m1 *(long) q; t = (BignumDblInt) m1 * (BignumDblInt) q;
if (t > ((unsigned long) r << 16) + ai1) { if (t > ((BignumDblInt) r << BIGNUM_INT_BITS) + ai1) {
q--; q--;
t -= m1; t -= m1;
r = (r + m0) & 0xffff; /* overflow? */ r = (r + m0) & BIGNUM_INT_MASK; /* overflow? */
if (r >= (unsigned long) m0 && if (r >= (BignumDblInt) m0 &&
t > ((unsigned long) r << 16) + ai1) q--; t > ((BignumDblInt) r << BIGNUM_INT_BITS) + ai1) q--;
} }
/* Subtract q * m from a[i...] */ /* Subtract q * m from a[i...] */
c = 0; c = 0;
for (k = mlen - 1; k >= 0; k--) { for (k = mlen - 1; k >= 0; k--) {
t = (long) q *(long) m[k]; t = (BignumDblInt) q * (BignumDblInt) m[k];
t += c; t += c;
c = t >> 16; c = t >> BIGNUM_INT_BITS;
if ((unsigned short) t > a[i + k]) if ((BignumInt) t > a[i + k])
c++; c++;
a[i + k] -= (unsigned short) t; a[i + k] -= (BignumInt) t;
} }
/* Add back m in case of borrow */ /* Add back m in case of borrow */
@ -190,13 +207,13 @@ static void internal_mod(unsigned short *a, int alen,
for (k = mlen - 1; k >= 0; k--) { for (k = mlen - 1; k >= 0; k--) {
t += m[k]; t += m[k];
t += a[i + k]; t += a[i + k];
a[i + k] = (unsigned short) t; a[i + k] = (BignumInt) t;
t = t >> 16; t = t >> BIGNUM_INT_BITS;
} }
q--; q--;
} }
if (quot) if (quot)
internal_add_shifted(quot, q, qshift + 16 * (alen - mlen - i)); internal_add_shifted(quot, q, qshift + BIGNUM_INT_BITS * (alen - mlen - i));
} }
} }
@ -208,7 +225,7 @@ static void internal_mod(unsigned short *a, int alen,
*/ */
Bignum modpow(Bignum base, Bignum exp, Bignum mod) Bignum modpow(Bignum base, Bignum exp, Bignum mod)
{ {
unsigned short *a, *b, *n, *m; BignumInt *a, *b, *n, *m;
int mshift; int mshift;
int mlen, i, j; int mlen, i, j;
Bignum result; Bignum result;
@ -216,22 +233,22 @@ Bignum modpow(Bignum base, Bignum exp, Bignum mod)
/* Allocate m of size mlen, copy mod to m */ /* Allocate m of size mlen, copy mod to m */
/* We use big endian internally */ /* We use big endian internally */
mlen = mod[0]; mlen = mod[0];
m = snewn(mlen, unsigned short); m = snewn(mlen, BignumInt);
for (j = 0; j < mlen; j++) for (j = 0; j < mlen; j++)
m[j] = mod[mod[0] - j]; m[j] = mod[mod[0] - j];
/* Shift m left to make msb bit set */ /* Shift m left to make msb bit set */
for (mshift = 0; mshift < 15; mshift++) for (mshift = 0; mshift < BIGNUM_INT_BITS-1; mshift++)
if ((m[0] << mshift) & 0x8000) if ((m[0] << mshift) & BIGNUM_TOP_BIT)
break; break;
if (mshift) { if (mshift) {
for (i = 0; i < mlen - 1; i++) for (i = 0; i < mlen - 1; i++)
m[i] = (m[i] << mshift) | (m[i + 1] >> (16 - mshift)); m[i] = (m[i] << mshift) | (m[i + 1] >> (BIGNUM_INT_BITS - mshift));
m[mlen - 1] = m[mlen - 1] << mshift; m[mlen - 1] = m[mlen - 1] << mshift;
} }
/* Allocate n of size mlen, copy base to n */ /* Allocate n of size mlen, copy base to n */
n = snewn(mlen, unsigned short); n = snewn(mlen, BignumInt);
i = mlen - base[0]; i = mlen - base[0];
for (j = 0; j < i; j++) for (j = 0; j < i; j++)
n[j] = 0; n[j] = 0;
@ -239,20 +256,20 @@ Bignum modpow(Bignum base, Bignum exp, Bignum mod)
n[i + j] = base[base[0] - j]; n[i + j] = base[base[0] - j];
/* Allocate a and b of size 2*mlen. Set a = 1 */ /* Allocate a and b of size 2*mlen. Set a = 1 */
a = snewn(2 * mlen, unsigned short); a = snewn(2 * mlen, BignumInt);
b = snewn(2 * mlen, unsigned short); b = snewn(2 * mlen, BignumInt);
for (i = 0; i < 2 * mlen; i++) for (i = 0; i < 2 * mlen; i++)
a[i] = 0; a[i] = 0;
a[2 * mlen - 1] = 1; a[2 * mlen - 1] = 1;
/* Skip leading zero bits of exp. */ /* Skip leading zero bits of exp. */
i = 0; i = 0;
j = 15; j = BIGNUM_INT_BITS-1;
while (i < exp[0] && (exp[exp[0] - i] & (1 << j)) == 0) { while (i < exp[0] && (exp[exp[0] - i] & (1 << j)) == 0) {
j--; j--;
if (j < 0) { if (j < 0) {
i++; i++;
j = 15; j = BIGNUM_INT_BITS-1;
} }
} }
@ -265,7 +282,7 @@ Bignum modpow(Bignum base, Bignum exp, Bignum mod)
internal_mul(b + mlen, n, a, mlen); internal_mul(b + mlen, n, a, mlen);
internal_mod(a, mlen * 2, m, mlen, NULL, 0); internal_mod(a, mlen * 2, m, mlen, NULL, 0);
} else { } else {
unsigned short *t; BignumInt *t;
t = a; t = a;
a = b; a = b;
b = t; b = t;
@ -273,17 +290,17 @@ Bignum modpow(Bignum base, Bignum exp, Bignum mod)
j--; j--;
} }
i++; i++;
j = 15; j = BIGNUM_INT_BITS-1;
} }
/* Fixup result in case the modulus was shifted */ /* Fixup result in case the modulus was shifted */
if (mshift) { if (mshift) {
for (i = mlen - 1; i < 2 * mlen - 1; i++) for (i = mlen - 1; i < 2 * mlen - 1; i++)
a[i] = (a[i] << mshift) | (a[i + 1] >> (16 - mshift)); a[i] = (a[i] << mshift) | (a[i + 1] >> (BIGNUM_INT_BITS - mshift));
a[2 * mlen - 1] = a[2 * mlen - 1] << mshift; a[2 * mlen - 1] = a[2 * mlen - 1] << mshift;
internal_mod(a, mlen * 2, m, mlen, NULL, 0); internal_mod(a, mlen * 2, m, mlen, NULL, 0);
for (i = 2 * mlen - 1; i >= mlen; i--) for (i = 2 * mlen - 1; i >= mlen; i--)
a[i] = (a[i] >> mshift) | (a[i - 1] << (16 - mshift)); a[i] = (a[i] >> mshift) | (a[i - 1] << (BIGNUM_INT_BITS - mshift));
} }
/* Copy result to buffer */ /* Copy result to buffer */
@ -317,7 +334,7 @@ Bignum modpow(Bignum base, Bignum exp, Bignum mod)
*/ */
Bignum modmul(Bignum p, Bignum q, Bignum mod) Bignum modmul(Bignum p, Bignum q, Bignum mod)
{ {
unsigned short *a, *n, *m, *o; BignumInt *a, *n, *m, *o;
int mshift; int mshift;
int pqlen, mlen, rlen, i, j; int pqlen, mlen, rlen, i, j;
Bignum result; Bignum result;
@ -325,24 +342,24 @@ Bignum modmul(Bignum p, Bignum q, Bignum mod)
/* Allocate m of size mlen, copy mod to m */ /* Allocate m of size mlen, copy mod to m */
/* We use big endian internally */ /* We use big endian internally */
mlen = mod[0]; mlen = mod[0];
m = snewn(mlen, unsigned short); m = snewn(mlen, BignumInt);
for (j = 0; j < mlen; j++) for (j = 0; j < mlen; j++)
m[j] = mod[mod[0] - j]; m[j] = mod[mod[0] - j];
/* Shift m left to make msb bit set */ /* Shift m left to make msb bit set */
for (mshift = 0; mshift < 15; mshift++) for (mshift = 0; mshift < BIGNUM_INT_BITS-1; mshift++)
if ((m[0] << mshift) & 0x8000) if ((m[0] << mshift) & BIGNUM_TOP_BIT)
break; break;
if (mshift) { if (mshift) {
for (i = 0; i < mlen - 1; i++) for (i = 0; i < mlen - 1; i++)
m[i] = (m[i] << mshift) | (m[i + 1] >> (16 - mshift)); m[i] = (m[i] << mshift) | (m[i + 1] >> (BIGNUM_INT_BITS - mshift));
m[mlen - 1] = m[mlen - 1] << mshift; m[mlen - 1] = m[mlen - 1] << mshift;
} }
pqlen = (p[0] > q[0] ? p[0] : q[0]); pqlen = (p[0] > q[0] ? p[0] : q[0]);
/* Allocate n of size pqlen, copy p to n */ /* Allocate n of size pqlen, copy p to n */
n = snewn(pqlen, unsigned short); n = snewn(pqlen, BignumInt);
i = pqlen - p[0]; i = pqlen - p[0];
for (j = 0; j < i; j++) for (j = 0; j < i; j++)
n[j] = 0; n[j] = 0;
@ -350,7 +367,7 @@ Bignum modmul(Bignum p, Bignum q, Bignum mod)
n[i + j] = p[p[0] - j]; n[i + j] = p[p[0] - j];
/* Allocate o of size pqlen, copy q to o */ /* Allocate o of size pqlen, copy q to o */
o = snewn(pqlen, unsigned short); o = snewn(pqlen, BignumInt);
i = pqlen - q[0]; i = pqlen - q[0];
for (j = 0; j < i; j++) for (j = 0; j < i; j++)
o[j] = 0; o[j] = 0;
@ -358,7 +375,7 @@ Bignum modmul(Bignum p, Bignum q, Bignum mod)
o[i + j] = q[q[0] - j]; o[i + j] = q[q[0] - j];
/* Allocate a of size 2*pqlen for result */ /* Allocate a of size 2*pqlen for result */
a = snewn(2 * pqlen, unsigned short); a = snewn(2 * pqlen, BignumInt);
/* Main computation */ /* Main computation */
internal_mul(n, o, a, pqlen); internal_mul(n, o, a, pqlen);
@ -367,11 +384,11 @@ Bignum modmul(Bignum p, Bignum q, Bignum mod)
/* Fixup result in case the modulus was shifted */ /* Fixup result in case the modulus was shifted */
if (mshift) { if (mshift) {
for (i = 2 * pqlen - mlen - 1; i < 2 * pqlen - 1; i++) for (i = 2 * pqlen - mlen - 1; i < 2 * pqlen - 1; i++)
a[i] = (a[i] << mshift) | (a[i + 1] >> (16 - mshift)); a[i] = (a[i] << mshift) | (a[i + 1] >> (BIGNUM_INT_BITS - mshift));
a[2 * pqlen - 1] = a[2 * pqlen - 1] << mshift; a[2 * pqlen - 1] = a[2 * pqlen - 1] << mshift;
internal_mod(a, pqlen * 2, m, mlen, NULL, 0); internal_mod(a, pqlen * 2, m, mlen, NULL, 0);
for (i = 2 * pqlen - 1; i >= 2 * pqlen - mlen; i--) for (i = 2 * pqlen - 1; i >= 2 * pqlen - mlen; i--)
a[i] = (a[i] >> mshift) | (a[i - 1] << (16 - mshift)); a[i] = (a[i] >> mshift) | (a[i - 1] << (BIGNUM_INT_BITS - mshift));
} }
/* Copy result to buffer */ /* Copy result to buffer */
@ -408,24 +425,24 @@ Bignum modmul(Bignum p, Bignum q, Bignum mod)
*/ */
static void bigdivmod(Bignum p, Bignum mod, Bignum result, Bignum quotient) static void bigdivmod(Bignum p, Bignum mod, Bignum result, Bignum quotient)
{ {
unsigned short *n, *m; BignumInt *n, *m;
int mshift; int mshift;
int plen, mlen, i, j; int plen, mlen, i, j;
/* Allocate m of size mlen, copy mod to m */ /* Allocate m of size mlen, copy mod to m */
/* We use big endian internally */ /* We use big endian internally */
mlen = mod[0]; mlen = mod[0];
m = snewn(mlen, unsigned short); m = snewn(mlen, BignumInt);
for (j = 0; j < mlen; j++) for (j = 0; j < mlen; j++)
m[j] = mod[mod[0] - j]; m[j] = mod[mod[0] - j];
/* Shift m left to make msb bit set */ /* Shift m left to make msb bit set */
for (mshift = 0; mshift < 15; mshift++) for (mshift = 0; mshift < BIGNUM_INT_BITS-1; mshift++)
if ((m[0] << mshift) & 0x8000) if ((m[0] << mshift) & BIGNUM_TOP_BIT)
break; break;
if (mshift) { if (mshift) {
for (i = 0; i < mlen - 1; i++) for (i = 0; i < mlen - 1; i++)
m[i] = (m[i] << mshift) | (m[i + 1] >> (16 - mshift)); m[i] = (m[i] << mshift) | (m[i + 1] >> (BIGNUM_INT_BITS - mshift));
m[mlen - 1] = m[mlen - 1] << mshift; m[mlen - 1] = m[mlen - 1] << mshift;
} }
@ -435,7 +452,7 @@ static void bigdivmod(Bignum p, Bignum mod, Bignum result, Bignum quotient)
plen = mlen + 1; plen = mlen + 1;
/* Allocate n of size plen, copy p to n */ /* Allocate n of size plen, copy p to n */
n = snewn(plen, unsigned short); n = snewn(plen, BignumInt);
for (j = 0; j < plen; j++) for (j = 0; j < plen; j++)
n[j] = 0; n[j] = 0;
for (j = 1; j <= p[0]; j++) for (j = 1; j <= p[0]; j++)
@ -447,11 +464,11 @@ static void bigdivmod(Bignum p, Bignum mod, Bignum result, Bignum quotient)
/* Fixup result in case the modulus was shifted */ /* Fixup result in case the modulus was shifted */
if (mshift) { if (mshift) {
for (i = plen - mlen - 1; i < plen - 1; i++) for (i = plen - mlen - 1; i < plen - 1; i++)
n[i] = (n[i] << mshift) | (n[i + 1] >> (16 - mshift)); n[i] = (n[i] << mshift) | (n[i + 1] >> (BIGNUM_INT_BITS - mshift));
n[plen - 1] = n[plen - 1] << mshift; n[plen - 1] = n[plen - 1] << mshift;
internal_mod(n, plen, m, mlen, quotient, 0); internal_mod(n, plen, m, mlen, quotient, 0);
for (i = plen - 1; i >= plen - mlen; i--) for (i = plen - 1; i >= plen - mlen; i--)
n[i] = (n[i] >> mshift) | (n[i - 1] << (16 - mshift)); n[i] = (n[i] >> mshift) | (n[i - 1] << (BIGNUM_INT_BITS - mshift));
} }
/* Copy result to buffer */ /* Copy result to buffer */
@ -478,7 +495,7 @@ void decbn(Bignum bn)
{ {
int i = 1; int i = 1;
while (i < bn[0] && bn[i] == 0) while (i < bn[0] && bn[i] == 0)
bn[i++] = 0xFFFF; bn[i++] = BIGNUM_INT_MASK;
bn[i]--; bn[i]--;
} }
@ -487,17 +504,14 @@ Bignum bignum_from_bytes(const unsigned char *data, int nbytes)
Bignum result; Bignum result;
int w, i; int w, i;
w = (nbytes + 1) / 2; /* bytes -> words */ w = (nbytes + BIGNUM_INT_BYTES - 1) / BIGNUM_INT_BYTES; /* bytes->words */
result = newbn(w); result = newbn(w);
for (i = 1; i <= w; i++) for (i = 1; i <= w; i++)
result[i] = 0; result[i] = 0;
for (i = nbytes; i--;) { for (i = nbytes; i--;) {
unsigned char byte = *data++; unsigned char byte = *data++;
if (i & 1) result[1 + i / BIGNUM_INT_BYTES] |= byte << (8*i % BIGNUM_INT_BITS);
result[1 + i / 2] |= byte << 8;
else
result[1 + i / 2] |= byte;
} }
while (result[0] > 1 && result[result[0]] == 0) while (result[0] > 1 && result[result[0]] == 0)
@ -533,9 +547,9 @@ int ssh1_read_bignum(const unsigned char *data, Bignum * result)
*/ */
int bignum_bitcount(Bignum bn) int bignum_bitcount(Bignum bn)
{ {
int bitcount = bn[0] * 16 - 1; int bitcount = bn[0] * BIGNUM_INT_BITS - 1;
while (bitcount >= 0 while (bitcount >= 0
&& (bn[bitcount / 16 + 1] >> (bitcount % 16)) == 0) bitcount--; && (bn[bitcount / BIGNUM_INT_BITS + 1] >> (bitcount % BIGNUM_INT_BITS)) == 0) bitcount--;
return bitcount + 1; return bitcount + 1;
} }
@ -560,12 +574,11 @@ int ssh2_bignum_length(Bignum bn)
*/ */
int bignum_byte(Bignum bn, int i) int bignum_byte(Bignum bn, int i)
{ {
if (i >= 2 * bn[0]) if (i >= BIGNUM_INT_BYTES * bn[0])
return 0; /* beyond the end */ return 0; /* beyond the end */
else if (i & 1)
return (bn[i / 2 + 1] >> 8) & 0xFF;
else else
return (bn[i / 2 + 1]) & 0xFF; return (bn[i / BIGNUM_INT_BYTES + 1] >>
((i % BIGNUM_INT_BYTES)*8)) & 0xFF;
} }
/* /*
@ -573,10 +586,10 @@ int bignum_byte(Bignum bn, int i)
*/ */
int bignum_bit(Bignum bn, int i) int bignum_bit(Bignum bn, int i)
{ {
if (i >= 16 * bn[0]) if (i >= BIGNUM_INT_BITS * bn[0])
return 0; /* beyond the end */ return 0; /* beyond the end */
else else
return (bn[i / 16 + 1] >> (i % 16)) & 1; return (bn[i / BIGNUM_INT_BITS + 1] >> (i % BIGNUM_INT_BITS)) & 1;
} }
/* /*
@ -584,11 +597,11 @@ int bignum_bit(Bignum bn, int i)
*/ */
void bignum_set_bit(Bignum bn, int bitnum, int value) void bignum_set_bit(Bignum bn, int bitnum, int value)
{ {
if (bitnum >= 16 * bn[0]) if (bitnum >= BIGNUM_INT_BITS * bn[0])
abort(); /* beyond the end */ abort(); /* beyond the end */
else { else {
int v = bitnum / 16 + 1; int v = bitnum / BIGNUM_INT_BITS + 1;
int mask = 1 << (bitnum % 16); int mask = 1 << (bitnum % BIGNUM_INT_BITS);
if (value) if (value)
bn[v] |= mask; bn[v] |= mask;
else else
@ -622,8 +635,8 @@ int bignum_cmp(Bignum a, Bignum b)
int amax = a[0], bmax = b[0]; int amax = a[0], bmax = b[0];
int i = (amax > bmax ? amax : bmax); int i = (amax > bmax ? amax : bmax);
while (i) { while (i) {
unsigned short aval = (i > amax ? 0 : a[i]); BignumInt aval = (i > amax ? 0 : a[i]);
unsigned short bval = (i > bmax ? 0 : b[i]); BignumInt bval = (i > bmax ? 0 : b[i]);
if (aval < bval) if (aval < bval)
return -1; return -1;
if (aval > bval) if (aval > bval)
@ -640,21 +653,21 @@ Bignum bignum_rshift(Bignum a, int shift)
{ {
Bignum ret; Bignum ret;
int i, shiftw, shiftb, shiftbb, bits; int i, shiftw, shiftb, shiftbb, bits;
unsigned short ai, ai1; BignumInt ai, ai1;
bits = bignum_bitcount(a) - shift; bits = bignum_bitcount(a) - shift;
ret = newbn((bits + 15) / 16); ret = newbn((bits + BIGNUM_INT_BITS - 1) / BIGNUM_INT_BITS);
if (ret) { if (ret) {
shiftw = shift / 16; shiftw = shift / BIGNUM_INT_BITS;
shiftb = shift % 16; shiftb = shift % BIGNUM_INT_BITS;
shiftbb = 16 - shiftb; shiftbb = BIGNUM_INT_BITS - shiftb;
ai1 = a[shiftw + 1]; ai1 = a[shiftw + 1];
for (i = 1; i <= ret[0]; i++) { for (i = 1; i <= ret[0]; i++) {
ai = ai1; ai = ai1;
ai1 = (i + shiftw + 1 <= a[0] ? a[i + shiftw + 1] : 0); ai1 = (i + shiftw + 1 <= a[0] ? a[i + shiftw + 1] : 0);
ret[i] = ((ai >> shiftb) | (ai1 << shiftbb)) & 0xFFFF; ret[i] = ((ai >> shiftb) | (ai1 << shiftbb)) & BIGNUM_INT_MASK;
} }
} }
@ -669,11 +682,11 @@ Bignum bigmuladd(Bignum a, Bignum b, Bignum addend)
int alen = a[0], blen = b[0]; int alen = a[0], blen = b[0];
int mlen = (alen > blen ? alen : blen); int mlen = (alen > blen ? alen : blen);
int rlen, i, maxspot; int rlen, i, maxspot;
unsigned short *workspace; BignumInt *workspace;
Bignum ret; Bignum ret;
/* mlen space for a, mlen space for b, 2*mlen for result */ /* mlen space for a, mlen space for b, 2*mlen for result */
workspace = snewn(mlen * 4, unsigned short); workspace = snewn(mlen * 4, BignumInt);
for (i = 0; i < mlen; i++) { for (i = 0; i < mlen; i++) {
workspace[0 * mlen + i] = (mlen - i <= a[0] ? a[mlen - i] : 0); workspace[0 * mlen + i] = (mlen - i <= a[0] ? a[mlen - i] : 0);
workspace[1 * mlen + i] = (mlen - i <= b[0] ? b[mlen - i] : 0); workspace[1 * mlen + i] = (mlen - i <= b[0] ? b[mlen - i] : 0);
@ -697,12 +710,12 @@ Bignum bigmuladd(Bignum a, Bignum b, Bignum addend)
/* now add in the addend, if any */ /* now add in the addend, if any */
if (addend) { if (addend) {
unsigned long carry = 0; BignumDblInt carry = 0;
for (i = 1; i <= rlen; i++) { for (i = 1; i <= rlen; i++) {
carry += (i <= ret[0] ? ret[i] : 0); carry += (i <= ret[0] ? ret[i] : 0);
carry += (i <= addend[0] ? addend[i] : 0); carry += (i <= addend[0] ? addend[i] : 0);
ret[i] = (unsigned short) carry & 0xFFFF; ret[i] = (BignumInt) carry & BIGNUM_INT_MASK;
carry >>= 16; carry >>= BIGNUM_INT_BITS;
if (ret[i] != 0 && i > maxspot) if (ret[i] != 0 && i > maxspot)
maxspot = i; maxspot = i;
} }
@ -729,7 +742,7 @@ Bignum bignum_bitmask(Bignum n)
{ {
Bignum ret = copybn(n); Bignum ret = copybn(n);
int i; int i;
unsigned short j; BignumInt j;
i = ret[0]; i = ret[0];
while (n[i] == 0 && i > 0) while (n[i] == 0 && i > 0)
@ -741,20 +754,21 @@ Bignum bignum_bitmask(Bignum n)
j = 2 * j + 1; j = 2 * j + 1;
ret[i] = j; ret[i] = j;
while (--i > 0) while (--i > 0)
ret[i] = 0xFFFF; ret[i] = BIGNUM_INT_MASK;
return ret; return ret;
} }
/* /*
* Convert a (max 32-bit) long into a bignum. * Convert a (max 32-bit) long into a bignum.
*/ */
Bignum bignum_from_long(unsigned long n) Bignum bignum_from_long(unsigned long nn)
{ {
Bignum ret; Bignum ret;
BignumDblInt n = nn;
ret = newbn(3); ret = newbn(3);
ret[1] = (unsigned short)(n & 0xFFFF); ret[1] = (BignumInt)(n & BIGNUM_INT_MASK);
ret[2] = (unsigned short)((n >> 16) & 0xFFFF); ret[2] = (BignumInt)((n >> BIGNUM_INT_BITS) & BIGNUM_INT_MASK);
ret[3] = 0; ret[3] = 0;
ret[0] = (ret[2] ? 2 : 1); ret[0] = (ret[2] ? 2 : 1);
return ret; return ret;
@ -763,18 +777,18 @@ Bignum bignum_from_long(unsigned long n)
/* /*
* Add a long to a bignum. * Add a long to a bignum.
*/ */
Bignum bignum_add_long(Bignum number, unsigned long addend) Bignum bignum_add_long(Bignum number, unsigned long addendx)
{ {
Bignum ret = newbn(number[0] + 1); Bignum ret = newbn(number[0] + 1);
int i, maxspot = 0; int i, maxspot = 0;
unsigned long carry = 0; BignumDblInt carry = 0, addend = addendx;
for (i = 1; i <= ret[0]; i++) { for (i = 1; i <= ret[0]; i++) {
carry += addend & 0xFFFF; carry += addend & BIGNUM_INT_MASK;
carry += (i <= number[0] ? number[i] : 0); carry += (i <= number[0] ? number[i] : 0);
addend >>= 16; addend >>= BIGNUM_INT_BITS;
ret[i] = (unsigned short) carry & 0xFFFF; ret[i] = (BignumInt) carry & BIGNUM_INT_MASK;
carry >>= 16; carry >>= BIGNUM_INT_BITS;
if (ret[i] != 0) if (ret[i] != 0)
maxspot = i; maxspot = i;
} }
@ -787,7 +801,7 @@ Bignum bignum_add_long(Bignum number, unsigned long addend)
*/ */
unsigned short bignum_mod_short(Bignum number, unsigned short modulus) unsigned short bignum_mod_short(Bignum number, unsigned short modulus)
{ {
unsigned long mod, r; BignumDblInt mod, r;
int i; int i;
r = 0; r = 0;
@ -797,10 +811,9 @@ unsigned short bignum_mod_short(Bignum number, unsigned short modulus)
return (unsigned short) r; return (unsigned short) r;
} }
#if 0 #ifdef DEBUG
void diagbn(char *prefix, Bignum md) void diagbn(char *prefix, Bignum md)
{ {
#ifdef DEBUG
int i, nibbles, morenibbles; int i, nibbles, morenibbles;
static const char hex[] = "0123456789ABCDEF"; static const char hex[] = "0123456789ABCDEF";
@ -818,7 +831,6 @@ void diagbn(char *prefix, Bignum md)
if (prefix) if (prefix)
debug(("\n")); debug(("\n"));
#endif
} }
#endif #endif
@ -899,13 +911,13 @@ Bignum modinv(Bignum number, Bignum modulus)
if (sign < 0) { if (sign < 0) {
/* set a new x to be modulus - x */ /* set a new x to be modulus - x */
Bignum newx = newbn(modulus[0]); Bignum newx = newbn(modulus[0]);
unsigned short carry = 0; BignumInt carry = 0;
int maxspot = 1; int maxspot = 1;
int i; int i;
for (i = 1; i <= newx[0]; i++) { for (i = 1; i <= newx[0]; i++) {
unsigned short aword = (i <= modulus[0] ? modulus[i] : 0); BignumInt aword = (i <= modulus[0] ? modulus[i] : 0);
unsigned short bword = (i <= x[0] ? x[i] : 0); BignumInt bword = (i <= x[0] ? x[i] : 0);
newx[i] = aword - bword - carry; newx[i] = aword - bword - carry;
bword = ~bword; bword = ~bword;
carry = carry ? (newx[i] >= bword) : (newx[i] > bword); carry = carry ? (newx[i] >= bword) : (newx[i] > bword);
@ -929,9 +941,9 @@ char *bignum_decimal(Bignum x)
{ {
int ndigits, ndigit; int ndigits, ndigit;
int i, iszero; int i, iszero;
unsigned long carry; BignumDblInt carry;
char *ret; char *ret;
unsigned short *workspace; BignumInt *workspace;
/* /*
* First, estimate the number of digits. Since log(10)/log(2) * First, estimate the number of digits. Since log(10)/log(2)
@ -956,7 +968,7 @@ char *bignum_decimal(Bignum x)
* repeatedly divide it by ten. Initialise this to the * repeatedly divide it by ten. Initialise this to the
* big-endian form of the number. * big-endian form of the number.
*/ */
workspace = snewn(x[0], unsigned short); workspace = snewn(x[0], BignumInt);
for (i = 0; i < x[0]; i++) for (i = 0; i < x[0]; i++)
workspace[i] = x[x[0] - i]; workspace[i] = x[x[0] - i];
@ -971,8 +983,8 @@ char *bignum_decimal(Bignum x)
iszero = 1; iszero = 1;
carry = 0; carry = 0;
for (i = 0; i < x[0]; i++) { for (i = 0; i < x[0]; i++) {
carry = (carry << 16) + workspace[i]; carry = (carry << BIGNUM_INT_BITS) + workspace[i];
workspace[i] = (unsigned short) (carry / 10); workspace[i] = (BignumInt) (carry / 10);
if (workspace[i]) if (workspace[i])
iszero = 0; iszero = 0;
carry %= 10; carry %= 10;