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#include <openssl/comp.h> 119#include <openssl/evp.h> 120#include <openssl/hmac.h> 121#include <openssl/md5.h> 122#include <openssl/rand.h> 123 124 125int dtls1_enc(SSL *s, int send) 126 { 127 SSL3_RECORD *rec; 128 EVP_CIPHER_CTX *ds; 129 unsigned long l; 130 int bs,i,ii,j,k,n=0; 131 const EVP_CIPHER *enc; 132 133 if (send) 134 { 135 if (s->write_hash != NULL) 136 n=EVP_MD_size(s->write_hash); 137 ds=s->enc_write_ctx; 138 rec= &(s->s3->wrec); 139 if (s->enc_write_ctx == NULL) 140 enc=NULL; 141 else 142 { 143 enc=EVP_CIPHER_CTX_cipher(s->enc_write_ctx); 144 if ( rec->data != rec->input) 145 /* we can't write into the input stream */ 146 fprintf(stderr, "%s:%d: rec->data != rec->input\n", 147 __FILE__, __LINE__); 148 else if ( EVP_CIPHER_block_size(ds->cipher) > 1) 149 { 150 if (!RAND_bytes(rec->input, EVP_CIPHER_block_size(ds->cipher))) 151 return -1; 152 } 153 } 154 } 155 else 156 { 157 if (s->read_hash != NULL) 158 n=EVP_MD_size(s->read_hash); 159 ds=s->enc_read_ctx; 160 rec= &(s->s3->rrec); 161 if (s->enc_read_ctx == NULL) 162 enc=NULL; 163 else 164 enc=EVP_CIPHER_CTX_cipher(s->enc_read_ctx); 165 } 166 167#ifdef KSSL_DEBUG 168 printf("dtls1_enc(%d)\n", send); 169#endif /* KSSL_DEBUG */ 170 171 if ((s->session == NULL) || (ds == NULL) || 172 (enc == NULL)) 173 { 174 memmove(rec->data,rec->input,rec->length); 175 rec->input=rec->data; 176 } 177 else 178 { 179 l=rec->length; 180 bs=EVP_CIPHER_block_size(ds->cipher); 181 182 if ((bs != 1) && send) 183 { 184 i=bs-((int)l%bs); 185 186 /* Add weird padding of upto 256 bytes */ 187 188 /* we need to add 'i' padding bytes of value j */ 189 j=i-1; 190 if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG) 191 { 192 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) 193 j++; 194 } 195 for (k=(int)l; k<(int)(l+i); k++) 196 rec->input[k]=j; 197 l+=i; 198 rec->length+=i; 199 } 200 201#ifdef KSSL_DEBUG 202 { 203 unsigned long ui; 204 printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n", 205 ds,rec->data,rec->input,l); 206 printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n", 207 ds->buf_len, ds->cipher->key_len, 208 DES_KEY_SZ, DES_SCHEDULE_SZ, 209 ds->cipher->iv_len); 210 printf("\t\tIV: "); 211 for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]); 212 printf("\n"); 213 printf("\trec->input="); 214 for (ui=0; ui<l; ui++) printf(" %02x", rec->input[ui]); 215 printf("\n"); 216 } 217#endif /* KSSL_DEBUG */ 218 219 if (!send) 220 { 221 if (l == 0 || l%bs != 0) 222 { 223 SSLerr(SSL_F_DTLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); 224 ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED); 225 return 0; 226 } 227 } 228 229 EVP_Cipher(ds,rec->data,rec->input,l); 230 231#ifdef KSSL_DEBUG 232 { 233 unsigned long i; 234 printf("\trec->data="); 235 for (i=0; i<l; i++) 236 printf(" %02x", rec->data[i]); printf("\n"); 237 } 238#endif /* KSSL_DEBUG */ 239 240 if ((bs != 1) && !send) 241 { 242 ii=i=rec->data[l-1]; /* padding_length */ 243 i++; 244 if (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG) 245 { 246 /* First packet is even in size, so check */ 247 if ((memcmp(s->s3->read_sequence, 248 "\0\0\0\0\0\0\0\0",8) == 0) && !(ii & 1)) 249 s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG; 250 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) 251 i--; 252 } 253 /* TLS 1.0 does not bound the number of padding bytes by the block size. 254 * All of them must have value 'padding_length'. */ 255 if (i > (int)rec->length) 256 { 257 /* Incorrect padding. SSLerr() and ssl3_alert are done 258 * by caller: we don't want to reveal whether this is 259 * a decryption error or a MAC verification failure 260 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 261 */ 262 return -1; 263 } 264 for (j=(int)(l-i); j<(int)l; j++) 265 { 266 if (rec->data[j] != ii) 267 { 268 /* Incorrect padding */ 269 return -1; 270 } 271 } 272 rec->length-=i; 273 274 rec->data += bs; /* skip the implicit IV */ 275 rec->input += bs; 276 rec->length -= bs; 277 } 278 } 279 return(1); 280 } 281 282