crypto/rsa/rsa_ssl.c

   1 /* crypto/rsa/rsa_ssl.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59
  60
  61 #include <stdio.h>
  62 #include "cryptlib.h"
  63 #include <openssl/bn.h>
  64 #include <openssl/rsa.h>
  65 #include <openssl/rand.h>
  66
  67 int RSA_padding_add_SSLv23(unsigned char *to, int tlen,
  68         const unsigned char *from, int flen)
  69         {
  70         int i,j;
  71         unsigned char *p;
  72
  73         if (flen > (tlen-11))
  74                 {
  75                 RSAerr(RSA_F_RSA_PADDING_ADD_SSLV23,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
  76                 return(0);
  77                 }
  78
  79         p=(unsigned char *)to;
  80
  81         *(p++)=0;
  82         *(p++)=2; /* Public Key BT (Block Type) */
  83
  84         /* pad out with non-zero random data */
  85         j=tlen-3-8-flen;
  86
  87         if (RAND_bytes(p,j) <= 0)
  88                 return(0);
  89         for (i=0; i<j; i++)
  90                 {
  91                 if (*p == '\0')
  92                         do      {
  93                                 if (RAND_bytes(p,1) <= 0)
  94                                         return(0);
  95                                 } while (*p == '\0');
  96                 p++;
  97                 }
  98
  99         memset(p,3,8);
 100         p+=8;
 101         *(p++)='\0';
 102
 103         memcpy(p,from,(unsigned int)flen);
 104         return(1);
 105         }
 106
 107 int RSA_padding_check_SSLv23(unsigned char *to, int tlen,
 108         const unsigned char *from, int flen, int num)
 109         {
 110         int i,j,k;
 111         const unsigned char *p;
 112
 113         p=from;
 114         if (flen < 10)
 115                 {
 116                 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_DATA_TOO_SMALL);
 117                 return(-1);
 118                 }
 119         if ((num != (flen+1)) || (*(p++) != 02))
 120                 {
 121                 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_BLOCK_TYPE_IS_NOT_02);
 122                 return(-1);
 123                 }
 124
 125         /* scan over padding data */
 126         j=flen-1; /* one for type */
 127         for (i=0; i<j; i++)
 128                 if (*(p++) == 0) break;
 129
 130         if ((i == j) || (i < 8))
 131                 {
 132                 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_NULL_BEFORE_BLOCK_MISSING);
 133                 return(-1);
 134                 }
 135         for (k = -9; k<-1; k++)
 136                 {
 137                 if (p[k] !=  0x03) break;
 138                 }
 139         if (k == -1)
 140                 {
 141                 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_SSLV3_ROLLBACK_ATTACK);
 142                 return(-1);
 143                 }
 144
 145         i++; /* Skip over the '\0' */
 146         j-=i;
 147         if (j > tlen)
 148                 {
 149                 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_DATA_TOO_LARGE);
 150                 return(-1);
 151                 }
 152         memcpy(to,p,(unsigned int)j);
 153
 154         return(j);
 155         }
 156