1 /* crypto/rsa/rsa_pk1.c */ 2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) 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 "cryptlib.h" 61 #include <openssl/bn.h> 62 #include <openssl/rsa.h> 63 #include <openssl/rand.h> 64 65 int RSA_padding_add_PKCS1_type_1(unsigned char *to, int tlen, 66 const unsigned char *from, int flen) 67 { 68 int j; 69 unsigned char *p; 70 71 if (flen > (tlen-RSA_PKCS1_PADDING_SIZE)) 72 { 73 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_1,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); 74 return(0); 75 } 76 77 p=(unsigned char *)to; 78 79 *(p++)=0; 80 *(p++)=1; /* Private Key BT (Block Type) */ 81 82 /* pad out with 0xff data */ 83 j=tlen-3-flen; 84 memset(p,0xff,j); 85 p+=j; 86 *(p++)='\0'; 87 memcpy(p,from,(unsigned int)flen); 88 return(1); 89 } 90 91 int RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen, 92 const unsigned char *from, int flen, int num) 93 { 94 int i,j; 95 const unsigned char *p; 96 97 p=from; 98 if ((num != (flen+1)) || (*(p++) != 01)) 99 { 100 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BLOCK_TYPE_IS_NOT_01); 101 return(-1); 102 } 103 104 /* scan over padding data */ 105 j=flen-1; /* one for type. */ 106 for (i=0; i<j; i++) 107 { 108 if (*p != 0xff) /* should decrypt to 0xff */ 109 { 110 if (*p == 0) 111 { p++; break; } 112 else { 113 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BAD_FIXED_HEADER_DECRYPT); 114 return(-1); 115 } 116 } 117 p++; 118 } 119 120 if (i == j) 121 { 122 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_NULL_BEFORE_BLOCK_MISSING); 123 return(-1); 124 } 125 126 if (i < 8) 127 { 128 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BAD_PAD_BYTE_COUNT); 129 return(-1); 130 } 131 i++; /* Skip over the '\0' */ 132 j-=i; 133 if (j > tlen) 134 { 135 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_DATA_TOO_LARGE); 136 return(-1); 137 } 138 memcpy(to,p,(unsigned int)j); 139 140 return(j); 141 } 142 143 int RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen, 144 const unsigned char *from, int flen) 145 { 146 int i,j; 147 unsigned char *p; 148 149 if (flen > (tlen-11)) 150 { 151 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_2,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 if (RAND_bytes(p,j) <= 0) 164 return(0); 165 for (i=0; i<j; i++) 166 { 167 if (*p == '\0') 168 do { 169 if (RAND_bytes(p,1) <= 0) 170 return(0); 171 } while (*p == '\0'); 172 p++; 173 } 174 175 *(p++)='\0'; 176 177 memcpy(p,from,(unsigned int)flen); 178 return(1); 179 } 180 181 int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen, 182 const unsigned char *from, int flen, int num) 183 { 184 int i,j; 185 const unsigned char *p; 186 187 p=from; 188 if ((num != (flen+1)) || (*(p++) != 02)) 189 { 190 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_BLOCK_TYPE_IS_NOT_02); 191 return(-1); 192 } 193 #ifdef PKCS1_CHECK 194 return(num-11); 195 #endif 196 197 /* scan over padding data */ 198 j=flen-1; /* one for type. */ 199 for (i=0; i<j; i++) 200 if (*(p++) == 0) break; 201 202 if (i == j) 203 { 204 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_NULL_BEFORE_BLOCK_MISSING); 205 return(-1); 206 } 207 208 if (i < 8) 209 { 210 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_BAD_PAD_BYTE_COUNT); 211 return(-1); 212 } 213 i++; /* Skip over the '\0' */ 214 j-=i; 215 if (j > tlen) 216 { 217 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_DATA_TOO_LARGE); 218 return(-1); 219 } 220 memcpy(to,p,(unsigned int)j); 221 222 return(j); 223 } 224 225
