version 1.2, 1999/09/28 04:45:36 |
version 1.10, 2000/04/12 09:39:10 |
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/* |
/* |
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* |
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* bufaux.c |
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* |
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* Author: Tatu Ylonen <ylo@cs.hut.fi> |
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* |
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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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* |
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* Created: Wed Mar 29 02:24:47 1995 ylo |
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* |
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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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* SSH2 packet format added by Markus Friedl |
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* |
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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("$Id$"); |
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#include "ssh.h" |
#include "ssh.h" |
#include <ssl/bn.h> |
#include <openssl/bn.h> |
#include "bufaux.h" |
#include "bufaux.h" |
#include "xmalloc.h" |
#include "xmalloc.h" |
#include "getput.h" |
#include "getput.h" |
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/* 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 |
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* by (bits+7)/8 bytes of binary data, msb first. |
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*/ |
void |
void |
buffer_put_bignum(Buffer *buffer, BIGNUM *value) |
buffer_put_bignum(Buffer *buffer, BIGNUM *value) |
{ |
{ |
int bits = BN_num_bits(value); |
int bits = BN_num_bits(value); |
int bin_size = (bits + 7) / 8; |
int bin_size = (bits + 7) / 8; |
char *buf = xmalloc(bin_size); |
char unsigned *buf = xmalloc(bin_size); |
int oi; |
int oi; |
char msg[2]; |
char msg[2]; |
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/* Get the value of in binary */ |
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oi = BN_bn2bin(value, buf); |
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assert(oi == bin_size); |
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/* Store the number of bits in the buffer in two bytes, msb first. */ |
/* Get the value of in binary */ |
PUT_16BIT(msg, bits); |
oi = BN_bn2bin(value, buf); |
buffer_append(buffer, msg, 2); |
if (oi != bin_size) |
/* Store the binary data. */ |
fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d", |
buffer_append(buffer, buf, oi); |
oi, bin_size); |
/* Clear the temporary data. */ |
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memset(buf, 0, bin_size); |
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xfree(buf); |
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} |
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/* Retrieves an BIGNUM from the buffer. */ |
/* 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, (char *)buf, oi); |
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memset(buf, 0, bin_size); |
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xfree(buf); |
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} |
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/* |
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* Retrieves an BIGNUM from the buffer. |
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*/ |
int |
int |
buffer_get_bignum(Buffer *buffer, BIGNUM *value) |
buffer_get_bignum(Buffer *buffer, BIGNUM *value) |
{ |
{ |
int bits, bytes; |
int bits, bytes; |
unsigned char buf[2], *bin; |
unsigned char buf[2], *bin; |
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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; |
bin = xmalloc(bytes); |
if (buffer_len(buffer) < bytes) |
buffer_get(buffer, bin, bytes); |
fatal("buffer_get_bignum: input buffer too small"); |
BN_bin2bn(bin, bytes, value); |
bin = (unsigned char*) buffer_ptr(buffer); |
xfree(bin); |
BN_bin2bn(bin, bytes, value); |
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buffer_consume(buffer, bytes); |
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return 2 + bytes; |
return 2 + bytes; |
} |
} |
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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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unsigned char *buf = xmalloc(bytes); |
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int oi; |
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int hasnohigh = 0; |
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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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unsigned char *uc = buf; |
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log("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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unsigned int buffer_get_int(Buffer *buffer) |
int |
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buffer_get_bignum2(Buffer *buffer, BIGNUM *value) |
{ |
{ |
unsigned char buf[4]; |
/**XXX should be two's-complement */ |
buffer_get(buffer, (char *)buf, 4); |
int len; |
return GET_32BIT(buf); |
unsigned char *bin = (unsigned char *)buffer_get_string(buffer, (unsigned int *)&len); |
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BN_bin2bn(bin, len, value); |
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xfree(bin); |
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return len; |
} |
} |
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/* Stores an integer in the buffer in 4 bytes, msb first. */ |
/* |
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* Returns an integer from the buffer (4 bytes, msb first). |
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*/ |
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unsigned int |
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buffer_get_int(Buffer *buffer) |
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{ |
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unsigned char buf[4]; |
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buffer_get(buffer, (char *) buf, 4); |
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return GET_32BIT(buf); |
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} |
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void buffer_put_int(Buffer *buffer, unsigned int value) |
/* |
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* Stores an integer in the buffer in 4 bytes, msb first. |
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*/ |
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void |
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buffer_put_int(Buffer *buffer, unsigned int value) |
{ |
{ |
char buf[4]; |
char buf[4]; |
PUT_32BIT(buf, value); |
PUT_32BIT(buf, value); |
buffer_append(buffer, buf, 4); |
buffer_append(buffer, buf, 4); |
} |
} |
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/* Returns an arbitrary binary string from the buffer. The string cannot |
/* |
be longer than 256k. The returned value points to memory allocated |
* Returns an arbitrary binary string from the buffer. The string cannot |
with xmalloc; it is the responsibility of the calling function to free |
* be longer than 256k. The returned value points to memory allocated |
the data. If length_ptr is non-NULL, the length of the returned data |
* with xmalloc; it is the responsibility of the calling function to free |
will be stored there. A null character will be automatically appended |
* the data. If length_ptr is non-NULL, the length of the returned data |
to the returned string, and is not counted in length. */ |
* 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. |
char *buffer_get_string(Buffer *buffer, unsigned int *length_ptr) |
*/ |
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char * |
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buffer_get_string(Buffer *buffer, unsigned int *length_ptr) |
{ |
{ |
unsigned int len; |
unsigned int len; |
char *value; |
char *value; |
/* Get the length. */ |
/* Get the length. */ |
len = buffer_get_int(buffer); |
len = buffer_get_int(buffer); |
if (len > 256*1024) |
if (len > 256 * 1024) |
fatal("Received packet with bad string length %d", len); |
fatal("Received packet with bad string length %d", len); |
/* Allocate space for the string. Add one byte for a null character. */ |
/* Allocate space for the string. Add one byte for a null character. */ |
value = xmalloc(len + 1); |
value = xmalloc(len + 1); |
/* Get the string. */ |
/* Get the string. */ |
buffer_get(buffer, value, len); |
buffer_get(buffer, value, len); |
/* Append a null character to make processing easier. */ |
/* Append a null character to make processing easier. */ |
value[len] = 0; |
value[len] = 0; |
/* Optionally return the length of the string. */ |
/* Optionally return the length of the string. */ |
if (length_ptr) |
if (length_ptr) |
*length_ptr = len; |
*length_ptr = len; |
return value; |
return value; |
} |
} |
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/* Stores and arbitrary binary string in the buffer. */ |
/* |
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* Stores and arbitrary binary string in the buffer. |
void buffer_put_string(Buffer *buffer, const void *buf, unsigned int len) |
*/ |
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void |
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buffer_put_string(Buffer *buffer, const void *buf, unsigned int len) |
{ |
{ |
buffer_put_int(buffer, len); |
buffer_put_int(buffer, len); |
buffer_append(buffer, buf, len); |
buffer_append(buffer, buf, len); |
} |
} |
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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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buffer_put_string(buffer, s, strlen(s)); |
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} |
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/* Returns a character from the buffer (0 - 255). */ |
/* |
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* Returns a character from the buffer (0 - 255). |
int buffer_get_char(Buffer *buffer) |
*/ |
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int |
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buffer_get_char(Buffer *buffer) |
{ |
{ |
char ch; |
char ch; |
buffer_get(buffer, &ch, 1); |
buffer_get(buffer, &ch, 1); |
return (unsigned char)ch; |
return (unsigned char) ch; |
} |
} |
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/* Stores a character in the buffer. */ |
/* |
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* Stores a character in the buffer. |
void buffer_put_char(Buffer *buffer, int value) |
*/ |
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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); |
buffer_append(buffer, &ch, 1); |
} |
} |