1 /* $OpenBSD: rsa_pk1.c,v 1.15 2017/01/29 17:49:23 beck 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 RSAerror(RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); 76 return 0; 77 } 78 79 p = (unsigned char *)to; 80 81 *(p++) = 0; 82 *(p++) = 1; /* Private Key BT (Block Type) */ 83 84 /* pad out with 0xff data */ 85 j = tlen - 3 - flen; 86 memset(p, 0xff, j); 87 p += j; 88 *(p++) = '\0'; 89 memcpy(p, from, flen); 90 91 return 1; 92 } 93 94 int 95 RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen, 96 const unsigned char *from, int flen, int num) 97 { 98 int i, j; 99 const unsigned char *p; 100 101 p = from; 102 if (num != flen + 1 || *(p++) != 01) { 103 RSAerror(RSA_R_BLOCK_TYPE_IS_NOT_01); 104 return -1; 105 } 106 107 /* scan over padding data */ 108 j = flen - 1; /* one for type. */ 109 for (i = 0; i < j; i++) { 110 if (*p != 0xff) { 111 /* should decrypt to 0xff */ 112 if (*p == 0) { 113 p++; 114 break; 115 } else { 116 RSAerror(RSA_R_BAD_FIXED_HEADER_DECRYPT); 117 return -1; 118 } 119 } 120 p++; 121 } 122 123 if (i == j) { 124 RSAerror(RSA_R_NULL_BEFORE_BLOCK_MISSING); 125 return -1; 126 } 127 128 if (i < 8) { 129 RSAerror(RSA_R_BAD_PAD_BYTE_COUNT); 130 return -1; 131 } 132 i++; /* Skip over the '\0' */ 133 j -= i; 134 if (j > tlen) { 135 RSAerror(RSA_R_DATA_TOO_LARGE); 136 return -1; 137 } 138 memcpy(to, p, j); 139 140 return j; 141 } 142 143 int 144 RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen, 145 const unsigned char *from, int flen) 146 { 147 int i, j; 148 unsigned char *p; 149 150 if (flen > tlen - 11) { 151 RSAerror(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 arc4random_buf(p, j); 164 for (i = 0; i < j; i++) { 165 while (*p == '\0') 166 arc4random_buf(p, 1); 167 p++; 168 } 169 170 *(p++) = '\0'; 171 172 memcpy(p, from, flen); 173 return 1; 174 } 175 176 int 177 RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen, 178 const unsigned char *from, int flen, int num) 179 { 180 int i, j; 181 const unsigned char *p; 182 183 p = from; 184 if (num != flen + 1 || *(p++) != 02) { 185 RSAerror(RSA_R_BLOCK_TYPE_IS_NOT_02); 186 return -1; 187 } 188 189 /* scan over padding data */ 190 j = flen - 1; /* one for type. */ 191 for (i = 0; i < j; i++) 192 if (*(p++) == 0) 193 break; 194 195 if (i == j) { 196 RSAerror(RSA_R_NULL_BEFORE_BLOCK_MISSING); 197 return -1; 198 } 199 200 if (i < 8) { 201 RSAerror(RSA_R_BAD_PAD_BYTE_COUNT); 202 return -1; 203 } 204 i++; /* Skip over the '\0' */ 205 j -= i; 206 if (j > tlen) { 207 RSAerror(RSA_R_DATA_TOO_LARGE); 208 return -1; 209 } 210 memcpy(to, p, j); 211 212 return j; 213 } 214