/*
-
-bufaux.c
-
-Author: Tatu Ylonen <ylo@cs.hut.fi>
-
-Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- All rights reserved
-
-Created: Wed Mar 29 02:24:47 1995 ylo
-
-Auxiliary functions for storing and retrieving various data types to/from
-Buffers.
-
-*/
+ * 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"
-RCSID("$Id$");
+RCSID("$OpenBSD: bufaux.c,v 1.35 2005/03/10 22:01:05 deraadt Exp $");
-#include "ssh.h"
#include <openssl/bn.h>
#include "bufaux.h"
#include "xmalloc.h"
#include "getput.h"
+#include "log.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. */
+/*
+ * 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);
+ return (-1);
+ }
+
+ /* Store the number of bits in the buffer in two bytes, msb first. */
+ PUT_16BIT(msg, bits);
+ buffer_append(buffer, msg, 2);
+ /* Store the binary data. */
+ buffer_append(buffer, (char *)buf, oi);
+
+ memset(buf, 0, bin_size);
+ xfree(buf);
+
+ return (0);
+}
void
-buffer_put_bignum(Buffer *buffer, BIGNUM *value)
-{
- int bits = BN_num_bits(value);
- int bin_size = (bits + 7) / 8;
- char *buf = xmalloc(bin_size);
- int oi;
- char msg[2];
-
- /* Get the value of in binary */
- oi = BN_bn2bin(value, buf);
- assert(oi == bin_size);
-
- /* Store the number of bits in the buffer in two bytes, msb first. */
- PUT_16BIT(msg, bits);
- buffer_append(buffer, msg, 2);
- /* Store the binary data. */
- buffer_append(buffer, buf, oi);
- /* Clear the temporary data. */
- memset(buf, 0, bin_size);
- xfree(buf);
-}
-
-/* Retrieves an BIGNUM from the buffer. */
+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_16BIT(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)
{
- int bits, bytes;
- unsigned char buf[2], *bin;
+ if (buffer_get_bignum_ret(buffer, value) == -1)
+ fatal("buffer_get_bignum: buffer error");
+}
- /* Get the number for bits. */
- buffer_get(buffer, (char *)buf, 2);
- bits = GET_16BIT(buf);
- /* Compute the number of binary bytes that follow. */
- bytes = (bits + 7) / 8;
- bin = xmalloc(bytes);
- buffer_get(buffer, bin, bytes);
- BN_bin2bn(bin, bytes, value);
- xfree(bin);
+/*
+ * 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 != 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);
+}
- return 2 + bytes;
+void
+buffer_put_bignum2(Buffer *buffer, const BIGNUM *value)
+{
+ if (buffer_put_bignum2_ret(buffer, value) == -1)
+ fatal("buffer_put_bignum2: buffer error");
}
-/* Returns an integer from the buffer (4 bytes, msb first). */
+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");
+ return (-1);
+ }
+ if (len > 8 * 1024) {
+ error("buffer_get_bignum2_ret: cannot handle BN of size %d", len);
+ return (-1);
+ }
+ BN_bin2bn(bin, len, value);
+ xfree(bin);
+ return (0);
+}
-unsigned int buffer_get_int(Buffer *buffer)
+void
+buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
{
- unsigned char buf[4];
- buffer_get(buffer, (char *)buf, 4);
- return GET_32BIT(buf);
+ if (buffer_get_bignum2_ret(buffer, value) == -1)
+ fatal("buffer_get_bignum2: buffer error");
}
-/* Stores an integer in the buffer in 4 bytes, msb first. */
+/*
+ * Returns integers from the buffer (msb first).
+ */
-void buffer_put_int(Buffer *buffer, unsigned int value)
+int
+buffer_get_short_ret(u_short *ret, Buffer *buffer)
{
- char buf[4];
- PUT_32BIT(buf, value);
- buffer_append(buffer, buf, 4);
+ u_char buf[2];
+
+ if (buffer_get_ret(buffer, (char *) buf, 2) == -1)
+ return (-1);
+ *ret = GET_16BIT(buf);
+ return (0);
}
-/* Returns an arbitrary binary string from the buffer. The string cannot
- be longer than 256k. The returned value points to memory allocated
- with xmalloc; it is the responsibility of the calling function to free
- the data. If length_ptr is non-NULL, the length of the returned data
- will be stored there. A null character will be automatically appended
- to the returned string, and is not counted in length. */
+u_short
+buffer_get_short(Buffer *buffer)
+{
+ u_short ret;
+
+ if (buffer_get_short_ret(&ret, buffer) == -1)
+ fatal("buffer_get_short: buffer error");
+
+ return (ret);
+}
-char *buffer_get_string(Buffer *buffer, unsigned int *length_ptr)
+int
+buffer_get_int_ret(u_int *ret, Buffer *buffer)
{
- unsigned int len;
- char *value;
- /* Get the length. */
- len = buffer_get_int(buffer);
- if (len > 256*1024)
- fatal("Received packet with bad string length %d", len);
- /* Allocate space for the string. Add one byte for a null character. */
- value = xmalloc(len + 1);
- /* Get the string. */
- buffer_get(buffer, value, len);
- /* Append a null character to make processing easier. */
- value[len] = 0;
- /* Optionally return the length of the string. */
- if (length_ptr)
- *length_ptr = len;
- return value;
+ u_char buf[4];
+
+ if (buffer_get_ret(buffer, (char *) buf, 4) == -1)
+ return (-1);
+ *ret = GET_32BIT(buf);
+ return (0);
}
-/* Stores and arbitrary binary string in the buffer. */
+u_int
+buffer_get_int(Buffer *buffer)
+{
+ u_int ret;
+
+ if (buffer_get_int_ret(&ret, buffer) == -1)
+ fatal("buffer_get_int: buffer error");
+
+ return (ret);
+}
-void buffer_put_string(Buffer *buffer, const void *buf, unsigned int len)
+int
+buffer_get_int64_ret(u_int64_t *ret, Buffer *buffer)
+{
+ u_char buf[8];
+
+ if (buffer_get_ret(buffer, (char *) buf, 8) == -1)
+ return (-1);
+ *ret = GET_64BIT(buf);
+ return (0);
+}
+
+u_int64_t
+buffer_get_int64(Buffer *buffer)
+{
+ u_int64_t ret;
+
+ if (buffer_get_int64_ret(&ret, buffer) == -1)
+ fatal("buffer_get_int: buffer error");
+
+ return (ret);
+}
+
+/*
+ * Stores integers in the buffer, msb first.
+ */
+void
+buffer_put_short(Buffer *buffer, u_short value)
+{
+ char buf[2];
+
+ PUT_16BIT(buf, value);
+ buffer_append(buffer, buf, 2);
+}
+
+void
+buffer_put_int(Buffer *buffer, u_int value)
+{
+ char buf[4];
+
+ PUT_32BIT(buf, value);
+ buffer_append(buffer, buf, 4);
+}
+
+void
+buffer_put_int64(Buffer *buffer, u_int64_t value)
+{
+ char buf[8];
+
+ PUT_64BIT(buf, value);
+ buffer_append(buffer, buf, 8);
+}
+
+/*
+ * Returns an arbitrary binary string from the buffer. The string cannot
+ * be longer than 256k. The returned value points to memory allocated
+ * with xmalloc; it is the responsibility of the calling function to free
+ * the data. If length_ptr is non-NULL, the length of the returned data
+ * will be stored there. A null character will be automatically appended
+ * to the returned string, and is not counted in length.
+ */
+void *
+buffer_get_string_ret(Buffer *buffer, u_int *length_ptr)
+{
+ u_char *value;
+ u_int len;
+
+ /* Get the length. */
+ len = buffer_get_int(buffer);
+ if (len > 256 * 1024) {
+ error("buffer_get_string_ret: bad string length %u", len);
+ return (NULL);
+ }
+ /* Allocate space for the string. Add one byte for a null character. */
+ value = xmalloc(len + 1);
+ /* Get the string. */
+ if (buffer_get_ret(buffer, value, len) == -1) {
+ error("buffer_get_string_ret: buffer_get failed");
+ xfree(value);
+ return (NULL);
+ }
+ /* Append a null character to make processing easier. */
+ value[len] = 0;
+ /* Optionally return the length of the string. */
+ if (length_ptr)
+ *length_ptr = len;
+ return (value);
+}
+
+void *
+buffer_get_string(Buffer *buffer, u_int *length_ptr)
{
- buffer_put_int(buffer, len);
- buffer_append(buffer, buf, len);
+ void *ret;
+
+ if ((ret = buffer_get_string_ret(buffer, length_ptr)) == NULL)
+ fatal("buffer_get_string: buffer error");
+ return (ret);
}
-/* Returns a character from the buffer (0 - 255). */
+/*
+ * Stores and arbitrary binary string in the buffer.
+ */
+void
+buffer_put_string(Buffer *buffer, const void *buf, u_int len)
+{
+ buffer_put_int(buffer, len);
+ buffer_append(buffer, buf, len);
+}
+void
+buffer_put_cstring(Buffer *buffer, const char *s)
+{
+ if (s == NULL)
+ fatal("buffer_put_cstring: s == NULL");
+ buffer_put_string(buffer, s, strlen(s));
+}
-int buffer_get_char(Buffer *buffer)
+/*
+ * Returns a character from the buffer (0 - 255).
+ */
+int
+buffer_get_char_ret(char *ret, Buffer *buffer)
{
- char ch;
- buffer_get(buffer, &ch, 1);
- return (unsigned char)ch;
+ if (buffer_get_ret(buffer, ret, 1) == -1) {
+ error("buffer_get_char_ret: buffer_get_ret failed");
+ return (-1);
+ }
+ return (0);
}
-/* Stores a character in the buffer. */
+int
+buffer_get_char(Buffer *buffer)
+{
+ char ch;
+
+ if (buffer_get_char_ret(&ch, buffer) == -1)
+ fatal("buffer_get_char: buffer error");
+ return (u_char) ch;
+}
-void buffer_put_char(Buffer *buffer, int value)
+/*
+ * Stores a character in the buffer.
+ */
+void
+buffer_put_char(Buffer *buffer, int value)
{
- char ch = value;
- buffer_append(buffer, &ch, 1);
+ char ch = value;
+
+ buffer_append(buffer, &ch, 1);
}