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Diff for /src/usr.bin/ssh/Attic/bufaux.c between version 1.1 and 1.20

version 1.1, 1999/09/26 20:53:33 version 1.20, 2001/12/19 17:16:13
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 /*  /*
    * 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.
    */
   
 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.  
   
 */  
   
 #include "includes.h"  #include "includes.h"
 RCSID("$Id$");  RCSID("$OpenBSD$");
   
 #include "ssh.h"  #include <openssl/bn.h>
 #include "gmp.h"  
 #include "bufaux.h"  #include "bufaux.h"
 #include "xmalloc.h"  #include "xmalloc.h"
 #include "getput.h"  #include "getput.h"
   #include "log.h"
   
 /* 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
    * by (bits+7)/8 bytes of binary data, msb first.
 void buffer_put_mp_int(Buffer *buffer, MP_INT *value)   */
   void
   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];
   
   /* Get the value of the number in hex.  Too bad that gmp does not allow  
      us to get it in binary. */  
   mpz_get_str(buf, 16, value);  
   
   /* 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. */  
   if (hex_size & 1)  
     {  
       sscanf(buf, "%1x", &byte);  
       buf[oi++] = byte;  
       i = 1;  
     }  
   
   /* 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);
     }  
           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. */  
   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, hex_size);  
   xfree(buf);  
 }  }
   
 /* Retrieves an MP_INT from the buffer. */  /*
    * Retrieves an BIGNUM from the buffer.
 int buffer_get_mp_int(Buffer *buffer, MP_INT *value)   */
   int
   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];  
   
   /* 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 (buffer_len(buffer) < bytes)
   hex = xmalloc(2 * bytes + 1);                  fatal("buffer_get_bignum: input buffer too small");
           bin = (u_char *) buffer_ptr(buffer);
   /* Read and convert the binary bytes into a hex string. */          BN_bin2bn(bin, bytes, value);
   for (i = 0; i < bytes; i++)          buffer_consume(buffer, bytes);
     {  
       unsigned char byte;          return 2 + bytes;
       buffer_get(buffer, (char *)&byte, 1);  
       sprintf(hex + 2 * i, "%02x", byte);  
     }  
   /* Read the hex string into a mp-int. */  
   mpz_set_str(value, hex, 16);  
   /* Free the string. */  
   xfree(hex);  
   return 2 + bytes;  
 }  }
   
 /* Returns an integer from the buffer (4 bytes, msb first). */  /*
    * Stores an BIGNUM in the buffer in SSH2 format.
    */
   void
   buffer_put_bignum2(Buffer *buffer, BIGNUM *value)
   {
           int bytes = BN_num_bytes(value) + 1;
           u_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;
                   u_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);
   }
   
 unsigned int buffer_get_int(Buffer *buffer)  int
   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);          u_char *bin = (u_char *)buffer_get_string(buffer, (u_int *)&len);
           BN_bin2bn(bin, len, value);
           xfree(bin);
           return len;
 }  }
   
 /* Stores an integer in the buffer in 4 bytes, msb first. */  /*
    * Returns an integer from the buffer (4 bytes, msb first).
    */
   u_int
   buffer_get_int(Buffer *buffer)
   {
           u_char buf[4];
           buffer_get(buffer, (char *) buf, 4);
           return GET_32BIT(buf);
   }
   
 void buffer_put_int(Buffer *buffer, unsigned int value)  u_int64_t
   buffer_get_int64(Buffer *buffer)
 {  {
   char buf[4];          u_char buf[8];
   PUT_32BIT(buf, value);          buffer_get(buffer, (char *) buf, 8);
   buffer_append(buffer, buf, 4);          return GET_64BIT(buf);
 }  }
   
 /* Returns an arbitrary binary string from the buffer.  The string cannot  /*
    be longer than 256k.  The returned value points to memory allocated   * Stores an integer in the buffer in 4 bytes, msb first.
    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  void
    will be stored there.  A null character will be automatically appended  buffer_put_int(Buffer *buffer, u_int value)
    to the returned string, and is not counted in length. */  {
           char buf[4];
           PUT_32BIT(buf, value);
           buffer_append(buffer, buf, 4);
   }
   
 char *buffer_get_string(Buffer *buffer, unsigned int *length_ptr)  void
   buffer_put_int64(Buffer *buffer, u_int64_t value)
 {  {
   unsigned int len;          char buf[8];
   char *value;          PUT_64BIT(buf, value);
   /* Get the length. */          buffer_append(buffer, buf, 8);
   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;  
 }  }
   
 /* Stores and arbitrary binary string in the buffer. */  /*
    * 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(Buffer *buffer, u_int *length_ptr)
   {
           u_int len;
           u_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;
   }
   
 void buffer_put_string(Buffer *buffer, const void *buf, unsigned int len)  /*
    * 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_put_int(buffer, len);
   buffer_append(buffer, buf, 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). */  /*
    * Returns a character from the buffer (0 - 255).
 int buffer_get_char(Buffer *buffer)   */
   int
   buffer_get_char(Buffer *buffer)
 {  {
   char ch;          char ch;
   buffer_get(buffer, &ch, 1);          buffer_get(buffer, &ch, 1);
   return (unsigned char)ch;          return (u_char) ch;
 }  }
   
 /* Stores a character in the buffer. */  /*
    * Stores a character in the buffer.
 void buffer_put_char(Buffer *buffer, int value)   */
   void
   buffer_put_char(Buffer *buffer, int value)
 {  {
   char ch = value;          char ch = value;
   buffer_append(buffer, &ch, 1);          buffer_append(buffer, &ch, 1);
 }  }
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