crypto/openssl-0.9.7d/crypto/rsa/rsa_pk1.c

   1 /* crypto/rsa/rsa_pk1.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 #include <stdio.h>
  60 #include "cryptlib.h"
  61 #include <openssl/bn.h>
  62 #include <openssl/rsa.h>
  63 #include <openssl/rand.h>
  64
  65 int RSA_padding_add_PKCS1_type_1(unsigned char *to, int tlen,
  66              const unsigned char *from, int flen)
  67         {
  68         int j;
  69         unsigned char *p;
  70
  71         if (flen > (tlen-RSA_PKCS1_PADDING_SIZE))
  72                 {
  73                 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_1,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
  74                 return(0);
  75                 }
  76
  77         p=(unsigned char *)to;
  78
  79         *(p++)=0;
  80         *(p++)=1; /* Private Key BT (Block Type) */
  81
  82         /* pad out with 0xff data */
  83         j=tlen-3-flen;
  84         memset(p,0xff,j);
  85         p+=j;
  86         *(p++)='\0';
  87         memcpy(p,from,(unsigned int)flen);
  88         return(1);
  89         }
  90
  91 int RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen,
  92              const unsigned char *from, int flen, int num)
  93         {
  94         int i,j;
  95         const unsigned char *p;
  96
  97         p=from;
  98         if ((num != (flen+1)) || (*(p++) != 01))
  99                 {
 100                 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BLOCK_TYPE_IS_NOT_01);
 101                 return(-1);
 102                 }
 103
 104         /* scan over padding data */
 105         j=flen-1; /* one for type. */
 106         for (i=0; i<j; i++)
 107                 {
 108                 if (*p != 0xff) /* should decrypt to 0xff */
 109                         {
 110                         if (*p == 0)
 111                                 { p++; break; }
 112                         else    {
 113                                 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BAD_FIXED_HEADER_DECRYPT);
 114                                 return(-1);
 115                                 }
 116                         }
 117                 p++;
 118                 }
 119
 120         if (i == j)
 121                 {
 122                 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_NULL_BEFORE_BLOCK_MISSING);
 123                 return(-1);
 124                 }
 125
 126         if (i < 8)
 127                 {
 128                 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BAD_PAD_BYTE_COUNT);
 129                 return(-1);
 130                 }
 131         i++; /* Skip over the '\0' */
 132         j-=i;
 133         if (j > tlen)
 134                 {
 135                 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_DATA_TOO_LARGE);
 136                 return(-1);
 137                 }
 138         memcpy(to,p,(unsigned int)j);
 139
 140         return(j);
 141         }
 142
 143 int RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen,
 144              const unsigned char *from, int flen)
 145         {
 146         int i,j;
 147         unsigned char *p;
 148
 149         if (flen > (tlen-11))
 150                 {
 151                 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_2,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
 152                 return(0);
 153                 }
 154
 155         p=(unsigned char *)to;
 156
 157         *(p++)=0;
 158         *(p++)=2; /* Public Key BT (Block Type) */
 159
 160         /* pad out with non-zero random data */
 161         j=tlen-3-flen;
 162
 163         if (RAND_bytes(p,j) <= 0)
 164                 return(0);
 165         for (i=0; i<j; i++)
 166                 {
 167                 if (*p == '\0')
 168                         do      {
 169                                 if (RAND_bytes(p,1) <= 0)
 170                                         return(0);
 171                                 } while (*p == '\0');
 172                 p++;
 173                 }
 174
 175         *(p++)='\0';
 176
 177         memcpy(p,from,(unsigned int)flen);
 178         return(1);
 179         }
 180
 181 int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen,
 182              const unsigned char *from, int flen, int num)
 183         {
 184         int i,j;
 185         const unsigned char *p;
 186
 187         p=from;
 188         if ((num != (flen+1)) || (*(p++) != 02))
 189                 {
 190                 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_BLOCK_TYPE_IS_NOT_02);
 191                 return(-1);
 192                 }
 193 #ifdef PKCS1_CHECK
 194         return(num-11);
 195 #endif
 196
 197         /* scan over padding data */
 198         j=flen-1; /* one for type. */
 199         for (i=0; i<j; i++)
 200                 if (*(p++) == 0) break;
 201
 202         if (i == j)
 203                 {
 204                 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_NULL_BEFORE_BLOCK_MISSING);
 205                 return(-1);
 206                 }
 207
 208         if (i < 8)
 209                 {
 210                 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_BAD_PAD_BYTE_COUNT);
 211                 return(-1);
 212                 }
 213         i++; /* Skip over the '\0' */
 214         j-=i;
 215         if (j > tlen)
 216                 {
 217                 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_DATA_TOO_LARGE);
 218                 return(-1);
 219                 }
 220         memcpy(to,p,(unsigned int)j);
 221
 222         return(j);
 223         }
 224