- dtucker@cvs.openbsd.org 2006/04/18 10:44:28
[bufaux.c bufbn.c]
Move Buffer bignum functions into their own file, bufbn.c. This means
that sftp and sftp-server (which use the Buffer functions in bufaux.c
but not the bignum ones) no longer need to be linked with libcrypto.
ok markus@
diff --git a/bufbn.c b/bufbn.c
new file mode 100644
index 0000000..56f4f6d
--- /dev/null
+++ b/bufbn.c
@@ -0,0 +1,209 @@
+/* $OpenBSD: bufbn.c,v 1.1 2006/04/18 10:44:28 dtucker Exp $*/
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ * Auxiliary functions for storing and retrieving various data types to/from
+ * Buffers.
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ *
+ * SSH2 packet format added by Markus Friedl
+ * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#include <openssl/bn.h>
+#include "bufaux.h"
+#include "xmalloc.h"
+#include "log.h"
+#include "misc.h"
+
+/*
+ * Stores an BIGNUM in the buffer with a 2-byte msb first bit count, followed
+ * by (bits+7)/8 bytes of binary data, msb first.
+ */
+int
+buffer_put_bignum_ret(Buffer *buffer, const BIGNUM *value)
+{
+ int bits = BN_num_bits(value);
+ int bin_size = (bits + 7) / 8;
+ u_char *buf = xmalloc(bin_size);
+ int oi;
+ char msg[2];
+
+ /* Get the value of in binary */
+ oi = BN_bn2bin(value, buf);
+ if (oi != bin_size) {
+ error("buffer_put_bignum_ret: BN_bn2bin() failed: oi %d != bin_size %d",
+ oi, bin_size);
+ xfree(buf);
+ return (-1);
+ }
+
+ /* Store the number of bits in the buffer in two bytes, msb first. */
+ put_u16(msg, bits);
+ buffer_append(buffer, msg, 2);
+ /* Store the binary data. */
+ buffer_append(buffer, buf, oi);
+
+ memset(buf, 0, bin_size);
+ xfree(buf);
+
+ return (0);
+}
+
+void
+buffer_put_bignum(Buffer *buffer, const BIGNUM *value)
+{
+ if (buffer_put_bignum_ret(buffer, value) == -1)
+ fatal("buffer_put_bignum: buffer error");
+}
+
+/*
+ * Retrieves an BIGNUM from the buffer.
+ */
+int
+buffer_get_bignum_ret(Buffer *buffer, BIGNUM *value)
+{
+ u_int bits, bytes;
+ u_char buf[2], *bin;
+
+ /* Get the number for bits. */
+ if (buffer_get_ret(buffer, (char *) buf, 2) == -1) {
+ error("buffer_get_bignum_ret: invalid length");
+ return (-1);
+ }
+ bits = get_u16(buf);
+ /* Compute the number of binary bytes that follow. */
+ bytes = (bits + 7) / 8;
+ if (bytes > 8 * 1024) {
+ error("buffer_get_bignum_ret: cannot handle BN of size %d", bytes);
+ return (-1);
+ }
+ if (buffer_len(buffer) < bytes) {
+ error("buffer_get_bignum_ret: input buffer too small");
+ return (-1);
+ }
+ bin = buffer_ptr(buffer);
+ BN_bin2bn(bin, bytes, value);
+ if (buffer_consume_ret(buffer, bytes) == -1) {
+ error("buffer_get_bignum_ret: buffer_consume failed");
+ return (-1);
+ }
+ return (0);
+}
+
+void
+buffer_get_bignum(Buffer *buffer, BIGNUM *value)
+{
+ if (buffer_get_bignum_ret(buffer, value) == -1)
+ fatal("buffer_get_bignum: buffer error");
+}
+
+/*
+ * Stores an BIGNUM in the buffer in SSH2 format.
+ */
+int
+buffer_put_bignum2_ret(Buffer *buffer, const BIGNUM *value)
+{
+ u_int bytes;
+ u_char *buf;
+ int oi;
+ u_int hasnohigh = 0;
+
+ if (BN_is_zero(value)) {
+ buffer_put_int(buffer, 0);
+ return 0;
+ }
+ if (value->neg) {
+ error("buffer_put_bignum2_ret: negative numbers not supported");
+ return (-1);
+ }
+ bytes = BN_num_bytes(value) + 1; /* extra padding byte */
+ if (bytes < 2) {
+ error("buffer_put_bignum2_ret: BN too small");
+ return (-1);
+ }
+ buf = xmalloc(bytes);
+ buf[0] = 0x00;
+ /* Get the value of in binary */
+ oi = BN_bn2bin(value, buf+1);
+ if (oi < 0 || (u_int)oi != bytes - 1) {
+ error("buffer_put_bignum2_ret: BN_bn2bin() failed: "
+ "oi %d != bin_size %d", oi, bytes);
+ xfree(buf);
+ return (-1);
+ }
+ hasnohigh = (buf[1] & 0x80) ? 0 : 1;
+ buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh);
+ memset(buf, 0, bytes);
+ xfree(buf);
+ return (0);
+}
+
+void
+buffer_put_bignum2(Buffer *buffer, const BIGNUM *value)
+{
+ if (buffer_put_bignum2_ret(buffer, value) == -1)
+ fatal("buffer_put_bignum2: buffer error");
+}
+
+int
+buffer_get_bignum2_ret(Buffer *buffer, BIGNUM *value)
+{
+ u_int len;
+ u_char *bin;
+
+ if ((bin = buffer_get_string_ret(buffer, &len)) == NULL) {
+ error("buffer_get_bignum2_ret: invalid bignum");
+ return (-1);
+ }
+
+ if (len > 0 && (bin[0] & 0x80)) {
+ error("buffer_get_bignum2_ret: negative numbers not supported");
+ xfree(bin);
+ return (-1);
+ }
+ if (len > 8 * 1024) {
+ error("buffer_get_bignum2_ret: cannot handle BN of size %d", len);
+ xfree(bin);
+ return (-1);
+ }
+ BN_bin2bn(bin, len, value);
+ xfree(bin);
+ return (0);
+}
+
+void
+buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
+{
+ if (buffer_get_bignum2_ret(buffer, value) == -1)
+ fatal("buffer_get_bignum2: buffer error");
+}