1 /* 2 * DTLS implementation written by Nagendra Modadugu 3 * (nagendra (at) cs.stanford.edu) for the OpenSSL project 2005. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * openssl-core (at) openssl.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay (at) cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh (at) cryptsoft.com). 56 * 57 */ 58 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 59 * All rights reserved. 60 * 61 * This package is an SSL implementation written 62 * by Eric Young (eay (at) cryptsoft.com). 63 * The implementation was written so as to conform with Netscapes SSL. 64 * 65 * This library is free for commercial and non-commercial use as long as 66 * the following conditions are aheared to. The following conditions 67 * apply to all code found in this distribution, be it the RC4, RSA, 68 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 69 * included with this distribution is covered by the same copyright terms 70 * except that the holder is Tim Hudson (tjh (at) cryptsoft.com). 71 * 72 * Copyright remains Eric Young's, and as such any Copyright notices in 73 * the code are not to be removed. 74 * If this package is used in a product, Eric Young should be given attribution 75 * as the author of the parts of the library used. 76 * This can be in the form of a textual message at program startup or 77 * in documentation (online or textual) provided with the package. 78 * 79 * Redistribution and use in source and binary forms, with or without 80 * modification, are permitted provided that the following conditions 81 * are met: 82 * 1. Redistributions of source code must retain the copyright 83 * notice, this list of conditions and the following disclaimer. 84 * 2. Redistributions in binary form must reproduce the above copyright 85 * notice, this list of conditions and the following disclaimer in the 86 * documentation and/or other materials provided with the distribution. 87 * 3. All advertising materials mentioning features or use of this software 88 * must display the following acknowledgement: 89 * "This product includes cryptographic software written by 90 * Eric Young (eay (at) cryptsoft.com)" 91 * The word 'cryptographic' can be left out if the rouines from the library 92 * being used are not cryptographic related :-). 93 * 4. If you include any Windows specific code (or a derivative thereof) from 94 * the apps directory (application code) you must include an acknowledgement: 95 * "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)" 96 * 97 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 98 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 99 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 100 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 101 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 102 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 103 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 104 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 105 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 106 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 107 * SUCH DAMAGE. 108 * 109 * The licence and distribution terms for any publically available version or 110 * derivative of this code cannot be changed. i.e. this code cannot simply be 111 * copied and put under another distribution licence 112 * [including the GNU Public Licence.] */ 113 114 #include <stdio.h> 115 #include <assert.h> 116 117 #include <openssl/evp.h> 118 #include <openssl/hmac.h> 119 #include <openssl/md5.h> 120 #include <openssl/rand.h> 121 122 #include "ssl_locl.h" 123 124 125 /* dtls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively. 126 * 127 * Returns: 128 * 0: (in non-constant time) if the record is publically invalid (i.e. too 129 * short etc). 130 * 1: if the record's padding is valid / the encryption was successful. 131 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending, 132 * an internal error occured. */ 133 int dtls1_enc(SSL *s, int send) 134 { 135 SSL3_RECORD *rec; 136 EVP_CIPHER_CTX *ds; 137 unsigned long l; 138 int bs,i,j,k,mac_size=0; 139 const EVP_CIPHER *enc; 140 141 if (send) 142 { 143 if (EVP_MD_CTX_md(s->write_hash)) 144 { 145 mac_size=EVP_MD_CTX_size(s->write_hash); 146 if (mac_size < 0) 147 return -1; 148 } 149 ds=s->enc_write_ctx; 150 rec= &(s->s3->wrec); 151 if (s->enc_write_ctx == NULL) 152 enc=NULL; 153 else 154 { 155 enc=EVP_CIPHER_CTX_cipher(s->enc_write_ctx); 156 if ( rec->data != rec->input) 157 /* we can't write into the input stream */ 158 fprintf(stderr, "%s:%d: rec->data != rec->input\n", 159 __FILE__, __LINE__); 160 else if ( EVP_CIPHER_block_size(ds->cipher) > 1) 161 { 162 if (RAND_bytes(rec->input, EVP_CIPHER_block_size(ds->cipher)) <= 0) 163 return -1; 164 } 165 } 166 } 167 else 168 { 169 if (EVP_MD_CTX_md(s->read_hash)) 170 { 171 mac_size=EVP_MD_CTX_size(s->read_hash); 172 assert(mac_size >= 0); 173 } 174 ds=s->enc_read_ctx; 175 rec= &(s->s3->rrec); 176 if (s->enc_read_ctx == NULL) 177 enc=NULL; 178 else 179 enc=EVP_CIPHER_CTX_cipher(s->enc_read_ctx); 180 } 181 182 #ifdef KSSL_DEBUG 183 printf("dtls1_enc(%d)\n", send); 184 #endif /* KSSL_DEBUG */ 185 186 if ((s->session == NULL) || (ds == NULL) || 187 (enc == NULL)) 188 { 189 memmove(rec->data,rec->input,rec->length); 190 rec->input=rec->data; 191 } 192 else 193 { 194 l=rec->length; 195 bs=EVP_CIPHER_block_size(ds->cipher); 196 197 if ((bs != 1) && send) 198 { 199 i=bs-((int)l%bs); 200 201 /* Add weird padding of upto 256 bytes */ 202 203 /* we need to add 'i' padding bytes of value j */ 204 j=i-1; 205 for (k=(int)l; k<(int)(l+i); k++) 206 rec->input[k]=j; 207 l+=i; 208 rec->length+=i; 209 } 210 211 #ifdef KSSL_DEBUG 212 { 213 unsigned long ui; 214 printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n", 215 ds,rec->data,rec->input,l); 216 printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n", 217 ds->buf_len, ds->cipher->key_len, 218 DES_KEY_SZ, DES_SCHEDULE_SZ, 219 ds->cipher->iv_len); 220 printf("\t\tIV: "); 221 for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]); 222 printf("\n"); 223 printf("\trec->input="); 224 for (ui=0; ui<l; ui++) printf(" %02x", rec->input[ui]); 225 printf("\n"); 226 } 227 #endif /* KSSL_DEBUG */ 228 229 if (!send) 230 { 231 if (l == 0 || l%bs != 0) 232 return 0; 233 } 234 235 EVP_Cipher(ds,rec->data,rec->input,l); 236 237 #ifdef KSSL_DEBUG 238 { 239 unsigned long i; 240 printf("\trec->data="); 241 for (i=0; i<l; i++) 242 printf(" %02x", rec->data[i]); printf("\n"); 243 } 244 #endif /* KSSL_DEBUG */ 245 246 if ((bs != 1) && !send) 247 return tls1_cbc_remove_padding(s, rec, bs, mac_size); 248 } 249 return(1); 250 } 251 252
