X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/70887be9ad821c22faf52c87597a707a8320a8cf..e557416818242c2e8b14ec03d321740fd83619e4:/sshrsa.c

diff --git a/sshrsa.c b/sshrsa.c
index d13f6cfe..bf54e409 100644
--- a/sshrsa.c
+++ b/sshrsa.c
@@ -9,12 +9,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "ssh.h"
-
-typedef unsigned short *Bignum;
-
-static unsigned short Zero[1] = { 0 };
-
 #if defined TESTMODE || defined RSADEBUG
 #ifndef DLVL
 #define DLVL 10000
@@ -42,201 +36,7 @@ static void bndebug(char *name, Bignum b) {
 #define leave(x)
 #endif
 
-static Bignum newbn(int length) {
-    Bignum b = malloc((length+1)*sizeof(unsigned short));
-    if (!b)
-	abort();		       /* FIXME */
-    b[0] = length;
-    return b;
-}
-
-static void freebn(Bignum b) {
-    free(b);
-}
-
-/*
- * Compute c = a * b.
- * Input is in the first len words of a and b.
- * Result is returned in the first 2*len words of c.
- */
-static void bigmul(unsigned short *a, unsigned short *b, unsigned short *c,
-                   int len)
-{
-    int i, j;
-    unsigned long ai, t;
-
-    for (j = len - 1; j >= 0; j--)
-	c[j+len] = 0;
-
-    for (i = len - 1; i >= 0; i--) {
-	ai = a[i];
-	t = 0;
-	for (j = len - 1; j >= 0; j--) {
-	    t += ai * (unsigned long) b[j];
-	    t += (unsigned long) c[i+j+1];
-	    c[i+j+1] = (unsigned short)t;
-	    t = t >> 16;
-	}
-	c[i] = (unsigned short)t;
-    }
-}
-
-/*
- * Compute a = a % m.
- * Input in first 2*len words of a and first len words of m.
- * Output in first 2*len words of a (of which first len words will be zero).
- * The MSW of m MUST have its high bit set.
- */
-static void bigmod(unsigned short *a, unsigned short *m, int len)
-{
-    unsigned short m0, m1;
-    unsigned int h;
-    int i, k;
-
-    /* Special case for len == 1 */
-    if (len == 1) {
-	a[1] = (((long) a[0] << 16) + a[1]) % m[0];
-	a[0] = 0;
-	return;
-    }
-
-    m0 = m[0];
-    m1 = m[1];
-
-    for (i = 0; i <= len; i++) {
-	unsigned long t;
-	unsigned int q, r, c;
-
-	if (i == 0) {
-	    h = 0;
-	} else {
-	    h = a[i-1];
-	    a[i-1] = 0;
-	}
-
-	/* Find q = h:a[i] / m0 */
-	t = ((unsigned long) h << 16) + a[i];
-	q = t / m0;
-	r = t % m0;
-
-	/* Refine our estimate of q by looking at
-	 h:a[i]:a[i+1] / m0:m1 */
-	t = (long) m1 * (long) q;
-	if (t > ((unsigned long) r << 16) + a[i+1]) {
-	    q--;
-	    t -= m1;
-	    r = (r + m0) & 0xffff; /* overflow? */
-	    if (r >= (unsigned long)m0 &&
-                t > ((unsigned long) r << 16) + a[i+1])
-		q--;
-	}
-
-	/* Substract q * m from a[i...] */
-	c = 0;
-	for (k = len - 1; k >= 0; k--) {
-	    t = (long) q * (long) m[k];
-	    t += c;
-	    c = t >> 16;
-	    if ((unsigned short) t > a[i+k]) c++;
-	    a[i+k] -= (unsigned short) t;
-	}
-
-	/* Add back m in case of borrow */
-	if (c != h) {
-	    t = 0;
-	    for (k = len - 1; k >= 0; k--) {
-		t += m[k];
-		t += a[i+k];
-		a[i+k] = (unsigned short)t;
-		t = t >> 16;
-	    }
-	}
-    }
-}
-
-/*
- * Compute (base ^ exp) % mod.
- * The base MUST be smaller than the modulus.
- * The most significant word of mod MUST be non-zero.
- * We assume that the result array is the same size as the mod array.
- */
-static void modpow(Bignum base, Bignum exp, Bignum mod, Bignum result)
-{
-    unsigned short *a, *b, *n, *m;
-    int mshift;
-    int mlen, i, j;
-
-    /* Allocate m of size mlen, copy mod to m */
-    /* We use big endian internally */
-    mlen = mod[0];
-    m = malloc(mlen * sizeof(unsigned short));
-    for (j = 0; j < mlen; j++) m[j] = mod[mod[0] - j];
-
-    /* Shift m left to make msb bit set */
-    for (mshift = 0; mshift < 15; mshift++)
-	if ((m[0] << mshift) & 0x8000) break;
-    if (mshift) {
-	for (i = 0; i < mlen - 1; i++)
-	    m[i] = (m[i] << mshift) | (m[i+1] >> (16-mshift));
-	m[mlen-1] = m[mlen-1] << mshift;
-    }
-
-    /* Allocate n of size mlen, copy base to n */
-    n = malloc(mlen * sizeof(unsigned short));
-    i = mlen - base[0];
-    for (j = 0; j < i; j++) n[j] = 0;
-    for (j = 0; j < base[0]; j++) n[i+j] = base[base[0] - j];
-
-    /* Allocate a and b of size 2*mlen. Set a = 1 */
-    a = malloc(2 * mlen * sizeof(unsigned short));
-    b = malloc(2 * mlen * sizeof(unsigned short));
-    for (i = 0; i < 2*mlen; i++) a[i] = 0;
-    a[2*mlen-1] = 1;
-
-    /* Skip leading zero bits of exp. */
-    i = 0; j = 15;
-    while (i < exp[0] && (exp[exp[0] - i] & (1 << j)) == 0) {
-	j--;
-	if (j < 0) { i++; j = 15; }
-    }
-
-    /* Main computation */
-    while (i < exp[0]) {
-	while (j >= 0) {
-	    bigmul(a + mlen, a + mlen, b, mlen);
-	    bigmod(b, m, mlen);
-	    if ((exp[exp[0] - i] & (1 << j)) != 0) {
-		bigmul(b + mlen, n, a, mlen);
-		bigmod(a, m, mlen);
-	    } else {
-		unsigned short *t;
-		t = a;  a = b;  b = t;
-	    }
-	    j--;
-	}
-	i++; j = 15;
-    }
-
-    /* Fixup result in case the modulus was shifted */
-    if (mshift) {
-	for (i = mlen - 1; i < 2*mlen - 1; i++)
-	    a[i] = (a[i] << mshift) | (a[i+1] >> (16-mshift));
-	a[2*mlen-1] = a[2*mlen-1] << mshift;
-	bigmod(a, m, mlen);
-	for (i = 2*mlen - 1; i >= mlen; i--)
-	    a[i] = (a[i] >> mshift) | (a[i-1] << (16-mshift));
-    }
-
-    /* Copy result to buffer */
-    for (i = 0; i < mlen; i++)
-	result[result[0] - i] = a[i+mlen];
-
-    /* Free temporary arrays */
-    for (i = 0; i < 2*mlen; i++) a[i] = 0; free(a);
-    for (i = 0; i < 2*mlen; i++) b[i] = 0; free(b);
-    for (i = 0; i < mlen; i++) m[i] = 0; free(m);
-    for (i = 0; i < mlen; i++) n[i] = 0; free(n);
-}
+#include "ssh.h"
 
 int makekey(unsigned char *data, struct RSAKey *result,
 	    unsigned char **keystr) {