version 1.1, 1999/09/26 20:53:33 |
version 1.29, 2003/04/08 20:21:28 |
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/* |
/* |
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* Author: Tatu Ylonen <ylo@cs.hut.fi> |
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
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* All rights reserved |
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* Auxiliary functions for storing and retrieving various data types to/from |
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* Buffers. |
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* |
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* As far as I am concerned, the code I have written for this software |
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* can be used freely for any purpose. Any derived versions of this |
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* software must be clearly marked as such, and if the derived work is |
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* incompatible with the protocol description in the RFC file, it must be |
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* called by a name other than "ssh" or "Secure Shell". |
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* |
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* |
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* SSH2 packet format added by Markus Friedl |
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* Copyright (c) 2000 Markus Friedl. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
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bufaux.c |
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Author: Tatu Ylonen <ylo@cs.hut.fi> |
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Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
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All rights reserved |
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Created: Wed Mar 29 02:24:47 1995 ylo |
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Auxiliary functions for storing and retrieving various data types to/from |
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Buffers. |
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*/ |
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#include "includes.h" |
#include "includes.h" |
RCSID("$Id$"); |
RCSID("$OpenBSD$"); |
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#include "ssh.h" |
#include <openssl/bn.h> |
#include "gmp.h" |
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#include "bufaux.h" |
#include "bufaux.h" |
#include "xmalloc.h" |
#include "xmalloc.h" |
#include "getput.h" |
#include "getput.h" |
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#include "log.h" |
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/* Stores an MP_INT 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 |
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* by (bits+7)/8 bytes of binary data, msb first. |
void buffer_put_mp_int(Buffer *buffer, MP_INT *value) |
*/ |
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void |
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buffer_put_bignum(Buffer *buffer, BIGNUM *value) |
{ |
{ |
int bits = mpz_sizeinbase(value, 2); |
int bits = BN_num_bits(value); |
int hex_size = mpz_sizeinbase(value, 16); |
int bin_size = (bits + 7) / 8; |
char *buf = xmalloc(hex_size + 2); |
u_char *buf = xmalloc(bin_size); |
int i, oi, byte; |
int oi; |
char msg[2]; |
char msg[2]; |
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/* Get the value of the number in hex. Too bad that gmp does not allow |
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us to get it in binary. */ |
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mpz_get_str(buf, 16, value); |
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/* i is "input index", oi is "output index". Both point to the same array, |
/* Get the value of in binary */ |
and start from the beginning. "input index" moves twice as fast. */ |
oi = BN_bn2bin(value, buf); |
i = 0; |
if (oi != bin_size) |
oi = 0; |
fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d", |
/* Check for an odd number of hex digits. Process the odd digit |
oi, bin_size); |
separately. */ |
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if (hex_size & 1) |
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{ |
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sscanf(buf, "%1x", &byte); |
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buf[oi++] = byte; |
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i = 1; |
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} |
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/* Convert the hex number into binary representation. */ |
/* Store the number of bits in the buffer in two bytes, msb first. */ |
for (; i < hex_size; i += 2) |
PUT_16BIT(msg, bits); |
{ |
buffer_append(buffer, msg, 2); |
sscanf(buf + i, "%2x", &byte); |
/* Store the binary data. */ |
buf[oi++] = byte; |
buffer_append(buffer, (char *)buf, oi); |
} |
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memset(buf, 0, bin_size); |
assert(oi == ((bits + 7) / 8)); |
xfree(buf); |
/* Store the number of bits in the buffer in two bytes, msb first. */ |
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PUT_16BIT(msg, bits); |
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buffer_append(buffer, msg, 2); |
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/* Store the binary data. */ |
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buffer_append(buffer, buf, oi); |
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/* Clear the temporary data. */ |
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memset(buf, 0, hex_size); |
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xfree(buf); |
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} |
} |
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/* Retrieves an MP_INT from the buffer. */ |
/* |
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* Retrieves an BIGNUM from the buffer. |
int buffer_get_mp_int(Buffer *buffer, MP_INT *value) |
*/ |
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void |
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buffer_get_bignum(Buffer *buffer, BIGNUM *value) |
{ |
{ |
int i, bits, bytes; |
int bits, bytes; |
char *hex; |
u_char buf[2], *bin; |
unsigned char buf[2]; |
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/* Get the number for bits. */ |
/* Get the number for bits. */ |
buffer_get(buffer, (char *)buf, 2); |
buffer_get(buffer, (char *) buf, 2); |
bits = GET_16BIT(buf); |
bits = GET_16BIT(buf); |
/* Compute the number of binary bytes that follow. */ |
/* Compute the number of binary bytes that follow. */ |
bytes = (bits + 7) / 8; |
bytes = (bits + 7) / 8; |
/* Allocate space for a corresponding hex string. */ |
if (bytes > 8 * 1024) |
hex = xmalloc(2 * bytes + 1); |
fatal("buffer_get_bignum: cannot handle BN of size %d", bytes); |
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if (buffer_len(buffer) < bytes) |
/* Read and convert the binary bytes into a hex string. */ |
fatal("buffer_get_bignum: input buffer too small"); |
for (i = 0; i < bytes; i++) |
bin = buffer_ptr(buffer); |
{ |
BN_bin2bn(bin, bytes, value); |
unsigned char byte; |
buffer_consume(buffer, bytes); |
buffer_get(buffer, (char *)&byte, 1); |
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sprintf(hex + 2 * i, "%02x", byte); |
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} |
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/* Read the hex string into a mp-int. */ |
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mpz_set_str(value, hex, 16); |
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/* Free the string. */ |
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xfree(hex); |
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return 2 + bytes; |
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} |
} |
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/* Returns an integer from the buffer (4 bytes, msb first). */ |
/* |
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* Stores an BIGNUM in the buffer in SSH2 format. |
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*/ |
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void |
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buffer_put_bignum2(Buffer *buffer, BIGNUM *value) |
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{ |
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int bytes = BN_num_bytes(value) + 1; |
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u_char *buf = xmalloc(bytes); |
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int oi; |
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int hasnohigh = 0; |
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unsigned int buffer_get_int(Buffer *buffer) |
buf[0] = '\0'; |
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/* Get the value of in binary */ |
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oi = BN_bn2bin(value, buf+1); |
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if (oi != bytes-1) |
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fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d", |
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oi, bytes); |
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hasnohigh = (buf[1] & 0x80) ? 0 : 1; |
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if (value->neg) { |
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/**XXX should be two's-complement */ |
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int i, carry; |
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u_char *uc = buf; |
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logit("negativ!"); |
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for (i = bytes-1, carry = 1; i>=0; i--) { |
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uc[i] ^= 0xff; |
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if (carry) |
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carry = !++uc[i]; |
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} |
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} |
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buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh); |
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memset(buf, 0, bytes); |
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xfree(buf); |
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} |
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/* XXX does not handle negative BNs */ |
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void |
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buffer_get_bignum2(Buffer *buffer, BIGNUM *value) |
{ |
{ |
unsigned char buf[4]; |
u_int len; |
buffer_get(buffer, (char *)buf, 4); |
u_char *bin = buffer_get_string(buffer, &len); |
return GET_32BIT(buf); |
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if (len > 8 * 1024) |
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fatal("buffer_get_bignum2: cannot handle BN of size %d", len); |
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BN_bin2bn(bin, len, value); |
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xfree(bin); |
} |
} |
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/* |
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* Returns integers from the buffer (msb first). |
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*/ |
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/* Stores an integer in the buffer in 4 bytes, msb first. */ |
u_short |
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buffer_get_short(Buffer *buffer) |
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{ |
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u_char buf[2]; |
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void buffer_put_int(Buffer *buffer, unsigned int value) |
buffer_get(buffer, (char *) buf, 2); |
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return GET_16BIT(buf); |
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} |
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u_int |
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buffer_get_int(Buffer *buffer) |
{ |
{ |
char buf[4]; |
u_char buf[4]; |
PUT_32BIT(buf, value); |
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buffer_append(buffer, buf, 4); |
buffer_get(buffer, (char *) buf, 4); |
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return GET_32BIT(buf); |
} |
} |
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/* Returns an arbitrary binary string from the buffer. The string cannot |
u_int64_t |
be longer than 256k. The returned value points to memory allocated |
buffer_get_int64(Buffer *buffer) |
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 |
u_char buf[8]; |
will be stored there. A null character will be automatically appended |
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to the returned string, and is not counted in length. */ |
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char *buffer_get_string(Buffer *buffer, unsigned int *length_ptr) |
buffer_get(buffer, (char *) buf, 8); |
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return GET_64BIT(buf); |
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} |
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/* |
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* Stores integers in the buffer, msb first. |
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*/ |
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void |
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buffer_put_short(Buffer *buffer, u_short value) |
{ |
{ |
unsigned int len; |
char buf[2]; |
char *value; |
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/* Get the length. */ |
PUT_16BIT(buf, value); |
len = buffer_get_int(buffer); |
buffer_append(buffer, buf, 2); |
if (len > 256*1024) |
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fatal("Received packet with bad string length %d", len); |
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/* Allocate space for the string. Add one byte for a null character. */ |
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value = xmalloc(len + 1); |
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/* Get the string. */ |
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buffer_get(buffer, value, len); |
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/* Append a null character to make processing easier. */ |
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value[len] = 0; |
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/* Optionally return the length of the string. */ |
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if (length_ptr) |
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*length_ptr = len; |
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return value; |
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} |
} |
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/* Stores and arbitrary binary string in the buffer. */ |
void |
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buffer_put_int(Buffer *buffer, u_int value) |
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{ |
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char buf[4]; |
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void buffer_put_string(Buffer *buffer, const void *buf, unsigned int len) |
PUT_32BIT(buf, value); |
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buffer_append(buffer, buf, 4); |
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} |
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void |
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buffer_put_int64(Buffer *buffer, u_int64_t value) |
{ |
{ |
buffer_put_int(buffer, len); |
char buf[8]; |
buffer_append(buffer, buf, len); |
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PUT_64BIT(buf, value); |
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buffer_append(buffer, buf, 8); |
} |
} |
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/* Returns a character from the buffer (0 - 255). */ |
/* |
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* Returns an arbitrary binary string from the buffer. The string cannot |
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* be longer than 256k. The returned value points to memory allocated |
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* with xmalloc; it is the responsibility of the calling function to free |
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* the data. If length_ptr is non-NULL, the length of the returned data |
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* will be stored there. A null character will be automatically appended |
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* to the returned string, and is not counted in length. |
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*/ |
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void * |
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buffer_get_string(Buffer *buffer, u_int *length_ptr) |
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{ |
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u_char *value; |
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u_int len; |
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int buffer_get_char(Buffer *buffer) |
/* Get the length. */ |
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len = buffer_get_int(buffer); |
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if (len > 256 * 1024) |
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fatal("buffer_get_string: bad string length %u", len); |
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/* Allocate space for the string. Add one byte for a null character. */ |
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value = xmalloc(len + 1); |
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/* Get the string. */ |
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buffer_get(buffer, value, len); |
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/* Append a null character to make processing easier. */ |
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value[len] = 0; |
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/* Optionally return the length of the string. */ |
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if (length_ptr) |
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*length_ptr = len; |
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return value; |
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} |
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/* |
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* Stores and arbitrary binary string in the buffer. |
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*/ |
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void |
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buffer_put_string(Buffer *buffer, const void *buf, u_int len) |
{ |
{ |
char ch; |
buffer_put_int(buffer, len); |
buffer_get(buffer, &ch, 1); |
buffer_append(buffer, buf, len); |
return (unsigned char)ch; |
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} |
} |
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void |
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buffer_put_cstring(Buffer *buffer, const char *s) |
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{ |
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if (s == NULL) |
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fatal("buffer_put_cstring: s == NULL"); |
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buffer_put_string(buffer, s, strlen(s)); |
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} |
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/* Stores a character in the buffer. */ |
/* |
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* Returns a character from the buffer (0 - 255). |
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*/ |
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int |
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buffer_get_char(Buffer *buffer) |
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{ |
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char ch; |
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void buffer_put_char(Buffer *buffer, int value) |
buffer_get(buffer, &ch, 1); |
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return (u_char) ch; |
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} |
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/* |
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* Stores a character in the buffer. |
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*/ |
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void |
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buffer_put_char(Buffer *buffer, int value) |
{ |
{ |
char ch = value; |
char ch = value; |
buffer_append(buffer, &ch, 1); |
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buffer_append(buffer, &ch, 1); |
} |
} |