lib/libcrypto/rsa/rsa_x931.c

   1 /* $OpenBSD: rsa_x931.c,v 1.10 2017/01/29 17:49:23 beck Exp $ */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project 2005.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 #include <stdio.h>
  60 #include <string.h>
  61
  62 #include <openssl/bn.h>
  63 #include <openssl/err.h>
  64 #include <openssl/objects.h>
  65 #include <openssl/rsa.h>
  66
  67 int
  68 RSA_padding_add_X931(unsigned char *to, int tlen, const unsigned char *from,
  69     int flen)
  70 {
  71         int j;
  72         unsigned char *p;
  73
  74         /*
  75          * Absolute minimum amount of padding is 1 header nibble, 1 padding
  76          * nibble and 2 trailer bytes: but 1 hash if is already in 'from'.
  77          */
  78         j = tlen - flen - 2;
  79
  80         if (j < 0) {
  81                 RSAerror(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, flen);
  99         p += flen;
 100         *p = 0xCC;
 101         return 1;
 102 }
 103
 104 int
 105 RSA_padding_check_X931(unsigned char *to, int tlen, const unsigned char *from,
 106     int flen, int num)
 107 {
 108         int i = 0, j;
 109         const unsigned char *p = from;
 110
 111         if (num != flen || (*p != 0x6A && *p != 0x6B)) {
 112                 RSAerror(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                                 RSAerror(RSA_R_INVALID_PADDING);
 124                                 return -1;
 125                         }
 126                 }
 127
 128                 if (i == 0) {
 129                         RSAerror(RSA_R_INVALID_PADDING);
 130                         return -1;
 131                 }
 132
 133                 j -= i;
 134         } else
 135                 j = flen - 2;
 136
 137         if (j < 0 || p[j] != 0xCC) {
 138                 RSAerror(RSA_R_INVALID_TRAILER);
 139                 return -1;
 140         }
 141
 142         memcpy(to, p, j);
 143
 144         return j;
 145 }
 146
 147 /* Translate between X931 hash ids and NIDs */
 148
 149 int
 150 RSA_X931_hash_id(int nid)
 151 {
 152         switch (nid) {
 153         case NID_sha1:
 154                 return 0x33;
 155         case NID_sha256:
 156                 return 0x34;
 157         case NID_sha384:
 158                 return 0x36;
 159         case NID_sha512:
 160                 return 0x35;
 161         }
 162
 163         return -1;
 164 }