crypto/rsa/rsa_x931.c

   1 /* rsa_x931.c */
   2 /*
   3  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   4  * 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    licensing@OpenSSL.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59
  60 #include <stdio.h>
  61 #include "cryptlib.h"
  62 #include <openssl/bn.h>
  63 #include <openssl/rsa.h>
  64 #include <openssl/rand.h>
  65 #include <openssl/objects.h>
  66
  67 int RSA_padding_add_X931(unsigned char *to, int tlen,
  68                          const unsigned char *from, int flen)
  69 {
  70     int j;
  71     unsigned char *p;
  72
  73     /*
  74      * Absolute minimum amount of padding is 1 header nibble, 1 padding
  75      * nibble and 2 trailer bytes: but 1 hash if is already in 'from'.
  76      */
  77
  78     j = tlen - flen - 2;
  79
  80     if (j < 0) {
  81         RSAerr(RSA_F_RSA_PADDING_ADD_X931, RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
  82         return -1;
  83     }
  84
  85     p = (unsigned char *)to;
  86
  87     /* If no padding start and end nibbles are in one byte */
  88     if (j == 0)
  89         *p++ = 0x6A;
  90     else {
  91         *p++ = 0x6B;
  92         if (j > 1) {
  93             memset(p, 0xBB, j - 1);
  94             p += j - 1;
  95         }
  96         *p++ = 0xBA;
  97     }
  98     memcpy(p, from, (unsigned int)flen);
  99     p += flen;
 100     *p = 0xCC;
 101     return (1);
 102 }
 103
 104 int RSA_padding_check_X931(unsigned char *to, int tlen,
 105                            const unsigned char *from, int flen, int num)
 106 {
 107     int i = 0, j;
 108     const unsigned char *p;
 109
 110     p = from;
 111     if ((num != flen) || ((*p != 0x6A) && (*p != 0x6B))) {
 112         RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_HEADER);
 113         return -1;
 114     }
 115
 116     if (*p++ == 0x6B) {
 117         j = flen - 3;
 118         for (i = 0; i < j; i++) {
 119             unsigned char c = *p++;
 120             if (c == 0xBA)
 121                 break;
 122             if (c != 0xBB) {
 123                 RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_PADDING);
 124                 return -1;
 125             }
 126         }
 127
 128         j -= i;
 129
 130         if (i == 0) {
 131             RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_PADDING);
 132             return -1;
 133         }
 134
 135     } else
 136         j = flen - 2;
 137
 138     if (p[j] != 0xCC) {
 139         RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_TRAILER);
 140         return -1;
 141     }
 142
 143     memcpy(to, p, (unsigned int)j);
 144
 145     return (j);
 146 }
 147
 148 /* Translate between X931 hash ids and NIDs */
 149
 150 int RSA_X931_hash_id(int nid)
 151 {
 152     switch (nid) {
 153     case NID_sha1:
 154         return 0x33;
 155
 156     case NID_sha256:
 157         return 0x34;
 158
 159     case NID_sha384:
 160         return 0x36;
 161
 162     case NID_sha512:
 163         return 0x35;
 164
 165     }
 166     return -1;
 167 }