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 } 165