1 /* crypto/rsa/rsa_ssl.c */ 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 "cryptlib.h" 61 #include <openssl/bn.h> 62 #include <openssl/rsa.h> 63 #include <openssl/rand.h> 64 65 int RSA_padding_add_SSLv23(unsigned char *to, int tlen, 66 const unsigned char *from, int flen) 67 { 68 int i,j; 69 unsigned char *p; 70 71 if (flen > (tlen-11)) 72 { 73 RSAerr(RSA_F_RSA_PADDING_ADD_SSLV23,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); 74 return(0); 75 } 76 77 p=(unsigned char *)to; 78 79 *(p++)=0; 80 *(p++)=2; /* Public Key BT (Block Type) */ 81 82 /* pad out with non-zero random data */ 83 j=tlen-3-8-flen; 84 85 if (RAND_bytes(p,j) <= 0) 86 return(0); 87 for (i=0; i<j; i++) 88 { 89 if (*p == '\0') 90 do { 91 if (RAND_bytes(p,1) <= 0) 92 return(0); 93 } while (*p == '\0'); 94 p++; 95 } 96 97 memset(p,3,8); 98 p+=8; 99 *(p++)='\0'; 100 101 memcpy(p,from,(unsigned int)flen); 102 return(1); 103 } 104 105 int RSA_padding_check_SSLv23(unsigned char *to, int tlen, 106 const unsigned char *from, int flen, int num) 107 { 108 int i,j,k; 109 const unsigned char *p; 110 111 p=from; 112 if (flen < 10) 113 { 114 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_DATA_TOO_SMALL); 115 return(-1); 116 } 117 if ((num != (flen+1)) || (*(p++) != 02)) 118 { 119 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_BLOCK_TYPE_IS_NOT_02); 120 return(-1); 121 } 122 123 /* scan over padding data */ 124 j=flen-1; /* one for type */ 125 for (i=0; i<j; i++) 126 if (*(p++) == 0) break; 127 128 if ((i == j) || (i < 8)) 129 { 130 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_NULL_BEFORE_BLOCK_MISSING); 131 return(-1); 132 } 133 for (k = -9; k<-1; k++) 134 { 135 if (p[k] != 0x03) break; 136 } 137 if (k == -1) 138 { 139 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_SSLV3_ROLLBACK_ATTACK); 140 return(-1); 141 } 142 143 i++; /* Skip over the '\0' */ 144 j-=i; 145 if (j > tlen) 146 { 147 RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_DATA_TOO_LARGE); 148 return(-1); 149 } 150 memcpy(to,p,(unsigned int)j); 151 152 return(j); 153 } 154 155