1/* ssl/d1_enc.c */ 2/* 3 * DTLS implementation written by Nagendra Modadugu 4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. 5 */ 6/* ==================================================================== 7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * openssl-core@openssl.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 60 * All rights reserved. 61 * 62 * This package is an SSL implementation written 63 * by Eric Young (eay@cryptsoft.com). 64 * The implementation was written so as to conform with Netscapes SSL. 65 * 66 * This library is free for commercial and non-commercial use as long as 67 * the following conditions are aheared to. The following conditions 68 * apply to all code found in this distribution, be it the RC4, RSA, 69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 70 * included with this distribution is covered by the same copyright terms 71 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 72 * 73 * Copyright remains Eric Young's, and as such any Copyright notices in 74 * the code are not to be removed. 75 * If this package is used in a product, Eric Young should be given attribution 76 * as the author of the parts of the library used. 77 * This can be in the form of a textual message at program startup or 78 * in documentation (online or textual) provided with the package. 79 * 80 * Redistribution and use in source and binary forms, with or without 81 * modification, are permitted provided that the following conditions 82 * are met: 83 * 1. Redistributions of source code must retain the copyright 84 * notice, this list of conditions and the following disclaimer. 85 * 2. Redistributions in binary form must reproduce the above copyright 86 * notice, this list of conditions and the following disclaimer in the 87 * documentation and/or other materials provided with the distribution. 88 * 3. All advertising materials mentioning features or use of this software 89 * must display the following acknowledgement: 90 * "This product includes cryptographic software written by 91 * Eric Young (eay@cryptsoft.com)" 92 * The word 'cryptographic' can be left out if the rouines from the library 93 * being used are not cryptographic related :-). 94 * 4. If you include any Windows specific code (or a derivative thereof) from 95 * the apps directory (application code) you must include an acknowledgement: 96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 97 * 98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 108 * SUCH DAMAGE. 109 * 110 * The licence and distribution terms for any publically available version or 111 * derivative of this code cannot be changed. i.e. this code cannot simply be 112 * copied and put under another distribution licence 113 * [including the GNU Public Licence.] 114 */ 115 116#include <stdio.h> 117#include "ssl_locl.h" 118#ifndef OPENSSL_NO_COMP 119#include <openssl/comp.h> 120#endif 121#include <openssl/evp.h> 122#include <openssl/hmac.h> 123#include <openssl/md5.h> 124#include <openssl/rand.h> 125#ifdef KSSL_DEBUG 126#include <openssl/des.h> 127#endif 128 129int dtls1_enc(SSL *s, int send) 130 { 131 SSL3_RECORD *rec; 132 EVP_CIPHER_CTX *ds; 133 unsigned long l; 134 int bs,i,ii,j,k,n=0; 135 const EVP_CIPHER *enc; 136 137 if (send) 138 { 139 if (s->write_hash != NULL) 140 n=EVP_MD_size(s->write_hash); 141 ds=s->enc_write_ctx; 142 rec= &(s->s3->wrec); 143 if (s->enc_write_ctx == NULL) 144 enc=NULL; 145 else 146 { 147 enc=EVP_CIPHER_CTX_cipher(s->enc_write_ctx); 148 if ( rec->data != rec->input) 149 /* we can't write into the input stream */ 150 fprintf(stderr, "%s:%d: rec->data != rec->input\n", 151 __FILE__, __LINE__); 152 else if ( EVP_CIPHER_block_size(ds->cipher) > 1) 153 { 154 if (RAND_bytes(rec->input, EVP_CIPHER_block_size(ds->cipher)) <= 0) 155 return -1; 156 } 157 } 158 } 159 else 160 { 161 if (s->read_hash != NULL) 162 n=EVP_MD_size(s->read_hash); 163 ds=s->enc_read_ctx; 164 rec= &(s->s3->rrec); 165 if (s->enc_read_ctx == NULL) 166 enc=NULL; 167 else 168 enc=EVP_CIPHER_CTX_cipher(s->enc_read_ctx); 169 } 170 171#ifdef KSSL_DEBUG 172 printf("dtls1_enc(%d)\n", send); 173#endif /* KSSL_DEBUG */ 174 175 if ((s->session == NULL) || (ds == NULL) || 176 (enc == NULL)) 177 { 178 memmove(rec->data,rec->input,rec->length); 179 rec->input=rec->data; 180 } 181 else 182 { 183 l=rec->length; 184 bs=EVP_CIPHER_block_size(ds->cipher); 185 186 if ((bs != 1) && send) 187 { 188 i=bs-((int)l%bs); 189 190 /* Add weird padding of upto 256 bytes */ 191 192 /* we need to add 'i' padding bytes of value j */ 193 j=i-1; 194 if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG) 195 { 196 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) 197 j++; 198 } 199 for (k=(int)l; k<(int)(l+i); k++) 200 rec->input[k]=j; 201 l+=i; 202 rec->length+=i; 203 } 204 205#ifdef KSSL_DEBUG 206 { 207 unsigned long ui; 208 printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n", 209 (void *)ds,rec->data,rec->input,l); 210 printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%ld %ld], %d iv_len\n", 211 ds->buf_len, ds->cipher->key_len, 212 (unsigned long)DES_KEY_SZ, 213 (unsigned long)DES_SCHEDULE_SZ, 214 ds->cipher->iv_len); 215 printf("\t\tIV: "); 216 for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]); 217 printf("\n"); 218 printf("\trec->input="); 219 for (ui=0; ui<l; ui++) printf(" %02x", rec->input[ui]); 220 printf("\n"); 221 } 222#endif /* KSSL_DEBUG */ 223 224 if (!send) 225 { 226 if (l == 0 || l%bs != 0) 227 { 228 SSLerr(SSL_F_DTLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); 229 ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED); 230 return 0; 231 } 232 } 233 234 EVP_Cipher(ds,rec->data,rec->input,l); 235 236#ifdef KSSL_DEBUG 237 { 238 unsigned long ki; 239 printf("\trec->data="); 240 for (ki=0; ki<l; ki++) 241 printf(" %02x", rec->data[ki]); printf("\n"); 242 } 243#endif /* KSSL_DEBUG */ 244 245 if ((bs != 1) && !send) 246 { 247 ii=i=rec->data[l-1]; /* padding_length */ 248 i++; 249 if (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG) 250 { 251 /* First packet is even in size, so check */ 252 if ((memcmp(s->s3->read_sequence, 253 "\0\0\0\0\0\0\0\0",8) == 0) && !(ii & 1)) 254 s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG; 255 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) 256 i--; 257 } 258 /* TLS 1.0 does not bound the number of padding bytes by the block size. 259 * All of them must have value 'padding_length'. */ 260 if (i > (int)rec->length) 261 { 262 /* Incorrect padding. SSLerr() and ssl3_alert are done 263 * by caller: we don't want to reveal whether this is 264 * a decryption error or a MAC verification failure 265 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 266 */ 267 return -1; 268 } 269 for (j=(int)(l-i); j<(int)l; j++) 270 { 271 if (rec->data[j] != ii) 272 { 273 /* Incorrect padding */ 274 return -1; 275 } 276 } 277 rec->length-=i; 278 279 rec->data += bs; /* skip the implicit IV */ 280 rec->input += bs; 281 rec->length -= bs; 282 } 283 } 284 return(1); 285 } 286 287