===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/Attic/bufaux.c,v
retrieving revision 1.26
retrieving revision 1.29.2.1
diff -u -r1.26 -r1.29.2.1
--- src/usr.bin/ssh/Attic/bufaux.c	2002/06/23 09:46:51	1.26
+++ src/usr.bin/ssh/Attic/bufaux.c	2004/02/28 03:51:32	1.29.2.1
@@ -37,7 +37,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: bufaux.c,v 1.26 2002/06/23 09:46:51 deraadt Exp $");
+RCSID("$OpenBSD: bufaux.c,v 1.29.2.1 2004/02/28 03:51:32 brad Exp $");
 
 #include <openssl/bn.h>
 #include "bufaux.h"
@@ -50,7 +50,7 @@
  * by (bits+7)/8 bytes of binary data, msb first.
  */
 void
-buffer_put_bignum(Buffer *buffer, BIGNUM *value)
+buffer_put_bignum(Buffer *buffer, const BIGNUM *value)
 {
 	int bits = BN_num_bits(value);
 	int bin_size = (bits + 7) / 8;
@@ -80,7 +80,7 @@
 void
 buffer_get_bignum(Buffer *buffer, BIGNUM *value)
 {
-	int bits, bytes;
+	u_int bits, bytes;
 	u_char buf[2], *bin;
 
 	/* Get the number for bits. */
@@ -88,6 +88,8 @@
 	bits = GET_16BIT(buf);
 	/* Compute the number of binary bytes that follow. */
 	bytes = (bits + 7) / 8;
+	if (bytes > 8 * 1024)
+		fatal("buffer_get_bignum: cannot handle BN of size %d", bytes);
 	if (buffer_len(buffer) < bytes)
 		fatal("buffer_get_bignum: input buffer too small");
 	bin = buffer_ptr(buffer);
@@ -99,31 +101,30 @@
  * Stores an BIGNUM in the buffer in SSH2 format.
  */
 void
-buffer_put_bignum2(Buffer *buffer, BIGNUM *value)
+buffer_put_bignum2(Buffer *buffer, const BIGNUM *value)
 {
-	int bytes = BN_num_bytes(value) + 1;
-	u_char *buf = xmalloc(bytes);
+	u_int bytes;
+	u_char *buf;
 	int oi;
-	int hasnohigh = 0;
+	u_int hasnohigh = 0;
 
+	if (BN_is_zero(value)) {
+		buffer_put_int(buffer, 0);
+		return;
+	}
+	if (value->neg)
+		fatal("buffer_put_bignum2: negative numbers not supported");
+	bytes = BN_num_bytes(value) + 1; /* extra padding byte */
+	if (bytes < 2)
+		fatal("buffer_put_bignum2: BN too small");
+	buf = xmalloc(bytes);
 	buf[0] = '\0';
 	/* Get the value of in binary */
 	oi = BN_bn2bin(value, buf+1);
 	if (oi != bytes-1)
-		fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
-		    oi, bytes);
+		fatal("buffer_put_bignum2: BN_bn2bin() failed: "
+		    "oi %d != bin_size %d", oi, bytes);
 	hasnohigh = (buf[1] & 0x80) ? 0 : 1;
-	if (value->neg) {
-		/**XXX should be two's-complement */
-		int i, carry;
-		u_char *uc = buf;
-		log("negativ!");
-		for (i = bytes-1, carry = 1; i>=0; i--) {
-			uc[i] ^= 0xff;
-			if (carry)
-				carry = !++uc[i];
-		}
-	}
 	buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh);
 	memset(buf, 0, bytes);
 	xfree(buf);
@@ -132,13 +133,17 @@
 void
 buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
 {
-	/**XXX should be two's-complement */
-	int len;
-	u_char *bin = buffer_get_string(buffer, (u_int *)&len);
+	u_int len;
+	u_char *bin = buffer_get_string(buffer, &len);
 
+	if (len > 0 && (bin[0] & 0x80))
+		fatal("buffer_get_bignum2: negative numbers not supported");
+	if (len > 8 * 1024)
+		fatal("buffer_get_bignum2: cannot handle BN of size %d", len);
 	BN_bin2bn(bin, len, value);
 	xfree(bin);
 }
+
 /*
  * Returns integers from the buffer (msb first).
  */
@@ -217,7 +222,7 @@
 	/* Get the length. */
 	len = buffer_get_int(buffer);
 	if (len > 256 * 1024)
-		fatal("buffer_get_string: bad string length %d", len);
+		fatal("buffer_get_string: bad string length %u", len);
 	/* Allocate space for the string.  Add one byte for a null character. */
 	value = xmalloc(len + 1);
 	/* Get the string. */