1 /* $OpenBSD: rsa_pk1.c,v 1.13 2014/07/11 08:44:49 jsing Exp $ */ 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 <stdlib.h> 61 #include <string.h> 62 63 #include <openssl/bn.h> 64 #include <openssl/err.h> 65 #include <openssl/rsa.h> 66 67 int 68 RSA_padding_add_PKCS1_type_1(unsigned char *to, int tlen, 69 const unsigned char *from, int flen) 70 { 71 int j; 72 unsigned char *p; 73 74 if (flen > (tlen - RSA_PKCS1_PADDING_SIZE)) { 75 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_1, 76 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); 77 return 0; 78 } 79 80 p = (unsigned char *)to; 81 82 *(p++) = 0; 83 *(p++) = 1; /* Private Key BT (Block Type) */ 84 85 /* pad out with 0xff data */ 86 j = tlen - 3 - flen; 87 memset(p, 0xff, j); 88 p += j; 89 *(p++) = '\0'; 90 memcpy(p, from, flen); 91 92 return 1; 93 } 94 95 int 96 RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen, 97 const unsigned char *from, int flen, int num) 98 { 99 int i, j; 100 const unsigned char *p; 101 102 p = from; 103 if (num != flen + 1 || *(p++) != 01) { 104 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, 105 RSA_R_BLOCK_TYPE_IS_NOT_01); 106 return -1; 107 } 108 109 /* scan over padding data */ 110 j = flen - 1; /* one for type. */ 111 for (i = 0; i < j; i++) { 112 if (*p != 0xff) { 113 /* should decrypt to 0xff */ 114 if (*p == 0) { 115 p++; 116 break; 117 } else { 118 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, 119 RSA_R_BAD_FIXED_HEADER_DECRYPT); 120 return -1; 121 } 122 } 123 p++; 124 } 125 126 if (i == j) { 127 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, 128 RSA_R_NULL_BEFORE_BLOCK_MISSING); 129 return -1; 130 } 131 132 if (i < 8) { 133 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, 134 RSA_R_BAD_PAD_BYTE_COUNT); 135 return -1; 136 } 137 i++; /* Skip over the '\0' */ 138 j -= i; 139 if (j > tlen) { 140 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1, 141 RSA_R_DATA_TOO_LARGE); 142 return -1; 143 } 144 memcpy(to, p, j); 145 146 return j; 147 } 148 149 int 150 RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen, 151 const unsigned char *from, int flen) 152 { 153 int i, j; 154 unsigned char *p; 155 156 if (flen > tlen - 11) { 157 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_2, 158 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); 159 return 0; 160 } 161 162 p = (unsigned char *)to; 163 164 *(p++) = 0; 165 *(p++) = 2; /* Public Key BT (Block Type) */ 166 167 /* pad out with non-zero random data */ 168 j = tlen - 3 - flen; 169 170 arc4random_buf(p, j); 171 for (i = 0; i < j; i++) { 172 while (*p == '\0') 173 arc4random_buf(p, 1); 174 p++; 175 } 176 177 *(p++) = '\0'; 178 179 memcpy(p, from, flen); 180 return 1; 181 } 182 183 int 184 RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen, 185 const unsigned char *from, int flen, int num) 186 { 187 int i, j; 188 const unsigned char *p; 189 190 p = from; 191 if (num != flen + 1 || *(p++) != 02) { 192 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2, 193 RSA_R_BLOCK_TYPE_IS_NOT_02); 194 return -1; 195 } 196 197 /* scan over padding data */ 198 j = flen - 1; /* one for type. */ 199 for (i = 0; i < j; i++) 200 if (*(p++) == 0) 201 break; 202 203 if (i == j) { 204 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2, 205 RSA_R_NULL_BEFORE_BLOCK_MISSING); 206 return -1; 207 } 208 209 if (i < 8) { 210 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2, 211 RSA_R_BAD_PAD_BYTE_COUNT); 212 return -1; 213 } 214 i++; /* Skip over the '\0' */ 215 j -= i; 216 if (j > tlen) { 217 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2, 218 RSA_R_DATA_TOO_LARGE); 219 return -1; 220 } 221 memcpy(to, p, j); 222 223 return j; 224 } 225