support ssh2 bignums

2 files changed, 56 insertions, 2 deletions

diff --git a/usr.bin/ssh/bufaux.c b/usr.bin/ssh/bufaux.c
index dddc41f9c69..16dce151bed 100644
--- a/usr.bin/ssh/bufaux.c
+++ b/usr.bin/ssh/bufaux.c
@@ -12,10 +12,12 @@
  * Auxiliary functions for storing and retrieving various data types to/from
  * Buffers.
  *
+ * SSH2 packet format added by Markus Friedl
+ *
  */
 
 #include "includes.h"
-RCSID("$Id: bufaux.c,v 1.8 2000/03/16 20:56:14 markus Exp $");
+RCSID("$Id: bufaux.c,v 1.9 2000/03/28 20:24:18 markus Exp $");
 
 #include "ssh.h"
 #include <ssl/bn.h>
@@ -76,6 +78,50 @@ buffer_get_bignum(Buffer *buffer, BIGNUM *value)
 }
 
 /*
+ * Stores an BIGNUM in the buffer in SSH2 format.
+ */
+void
+buffer_put_bignum2(Buffer *buffer, BIGNUM *value)
+{
+	int bytes = BN_num_bytes(value) + 1;
+	unsigned char *buf = xmalloc(bytes);
+	int oi;
+	int hasnohigh = 0;
+	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);
+	hasnohigh = (buf[1] & 0x80) ? 0 : 1;
+	if (value->neg) {
+		/**XXX should be two's-complement */
+		int i, carry;
+		unsigned 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);
+}
+
+int
+buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
+{
+	/**XXX should be two's-complement */
+	int len;
+	unsigned char *bin = (unsigned char *)buffer_get_string(buffer, (unsigned int *)&len);
+	BN_bin2bn(bin, len, value);
+	xfree(bin);
+	return len;
+}
+
+/*
  * Returns an integer from the buffer (4 bytes, msb first).
  */
 unsigned int 
@@ -135,6 +181,11 @@ buffer_put_string(Buffer *buffer, const void *buf, unsigned int len)
 	buffer_put_int(buffer, len);
 	buffer_append(buffer, buf, len);
 }
+void 
+buffer_put_cstring(Buffer *buffer, const char *s)
+{
+	buffer_put_string(buffer, s, strlen(s));
+}
 
 /*
  * Returns a character from the buffer (0 - 255).
diff --git a/usr.bin/ssh/bufaux.h b/usr.bin/ssh/bufaux.h
index 124a2656ba5..f21491f5c1c 100644
--- a/usr.bin/ssh/bufaux.h
+++ b/usr.bin/ssh/bufaux.h
@@ -11,7 +11,7 @@
  * 
  */
 
-/* RCSID("$Id: bufaux.h,v 1.4 1999/11/24 19:53:44 markus Exp $"); */
+/* RCSID("$Id: bufaux.h,v 1.5 2000/03/28 20:24:18 markus Exp $"); */
 
 #ifndef BUFAUX_H
 #define BUFAUX_H
@@ -23,9 +23,11 @@
  * by (bits+7)/8 bytes of binary data, msb first.
  */
 void    buffer_put_bignum(Buffer * buffer, BIGNUM * value);
+void    buffer_put_bignum2(Buffer * buffer, BIGNUM * value);
 
 /* Retrieves an BIGNUM from the buffer. */
 int     buffer_get_bignum(Buffer * buffer, BIGNUM * value);
+int	buffer_get_bignum2(Buffer *buffer, BIGNUM * value);
 
 /* Returns an integer from the buffer (4 bytes, msb first). */
 unsigned int buffer_get_int(Buffer * buffer);
@@ -51,5 +53,6 @@ char   *buffer_get_string(Buffer * buffer, unsigned int *length_ptr);
 
 /* Stores and arbitrary binary string in the buffer. */
 void    buffer_put_string(Buffer * buffer, const void *buf, unsigned int len);
+void	buffer_put_cstring(Buffer *buffer, const char *s);
 
 #endif				/* BUFAUX_H */