Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 1 | /* crypto/des/enc_read.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 <errno.h> |
| 61 | #include "cryptlib.h" |
| 62 | #include "des_locl.h" |
| 63 | |
| 64 | /* This has some uglies in it but it works - even over sockets. */ |
| 65 | /*extern int errno;*/ |
| 66 | OPENSSL_IMPLEMENT_GLOBAL(int,DES_rw_mode,DES_PCBC_MODE) |
| 67 | |
| 68 | |
| 69 | /* |
| 70 | * WARNINGS: |
| 71 | * |
| 72 | * - The data format used by DES_enc_write() and DES_enc_read() |
| 73 | * has a cryptographic weakness: When asked to write more |
| 74 | * than MAXWRITE bytes, DES_enc_write will split the data |
| 75 | * into several chunks that are all encrypted |
| 76 | * using the same IV. So don't use these functions unless you |
| 77 | * are sure you know what you do (in which case you might |
| 78 | * not want to use them anyway). |
| 79 | * |
| 80 | * - This code cannot handle non-blocking sockets. |
| 81 | * |
| 82 | * - This function uses an internal state and thus cannot be |
| 83 | * used on multiple files. |
| 84 | */ |
| 85 | |
| 86 | |
| 87 | int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched, |
| 88 | DES_cblock *iv) |
| 89 | { |
| 90 | #if defined(OPENSSL_NO_POSIX_IO) |
| 91 | return(0); |
| 92 | #else |
| 93 | /* data to be unencrypted */ |
| 94 | int net_num=0; |
| 95 | static unsigned char *net=NULL; |
| 96 | /* extra unencrypted data |
| 97 | * for when a block of 100 comes in but is des_read one byte at |
| 98 | * a time. */ |
| 99 | static unsigned char *unnet=NULL; |
| 100 | static int unnet_start=0; |
| 101 | static int unnet_left=0; |
| 102 | static unsigned char *tmpbuf=NULL; |
| 103 | int i; |
| 104 | long num=0,rnum; |
| 105 | unsigned char *p; |
| 106 | |
| 107 | if (tmpbuf == NULL) |
| 108 | { |
| 109 | tmpbuf=OPENSSL_malloc(BSIZE); |
| 110 | if (tmpbuf == NULL) return(-1); |
| 111 | } |
| 112 | if (net == NULL) |
| 113 | { |
| 114 | net=OPENSSL_malloc(BSIZE); |
| 115 | if (net == NULL) return(-1); |
| 116 | } |
| 117 | if (unnet == NULL) |
| 118 | { |
| 119 | unnet=OPENSSL_malloc(BSIZE); |
| 120 | if (unnet == NULL) return(-1); |
| 121 | } |
| 122 | /* left over data from last decrypt */ |
| 123 | if (unnet_left != 0) |
| 124 | { |
| 125 | if (unnet_left < len) |
| 126 | { |
| 127 | /* we still still need more data but will return |
| 128 | * with the number of bytes we have - should always |
| 129 | * check the return value */ |
| 130 | memcpy(buf,&(unnet[unnet_start]), |
| 131 | unnet_left); |
| 132 | /* eay 26/08/92 I had the next 2 lines |
| 133 | * reversed :-( */ |
| 134 | i=unnet_left; |
| 135 | unnet_start=unnet_left=0; |
| 136 | } |
| 137 | else |
| 138 | { |
| 139 | memcpy(buf,&(unnet[unnet_start]),len); |
| 140 | unnet_start+=len; |
| 141 | unnet_left-=len; |
| 142 | i=len; |
| 143 | } |
| 144 | return(i); |
| 145 | } |
| 146 | |
| 147 | /* We need to get more data. */ |
| 148 | if (len > MAXWRITE) len=MAXWRITE; |
| 149 | |
| 150 | /* first - get the length */ |
| 151 | while (net_num < HDRSIZE) |
| 152 | { |
| 153 | #ifndef OPENSSL_SYS_WIN32 |
| 154 | i=read(fd,(void *)&(net[net_num]),HDRSIZE-net_num); |
| 155 | #else |
| 156 | i=_read(fd,(void *)&(net[net_num]),HDRSIZE-net_num); |
| 157 | #endif |
| 158 | #ifdef EINTR |
| 159 | if ((i == -1) && (errno == EINTR)) continue; |
| 160 | #endif |
| 161 | if (i <= 0) return(0); |
| 162 | net_num+=i; |
| 163 | } |
| 164 | |
| 165 | /* we now have at net_num bytes in net */ |
| 166 | p=net; |
| 167 | /* num=0; */ |
| 168 | n2l(p,num); |
| 169 | /* num should be rounded up to the next group of eight |
| 170 | * we make sure that we have read a multiple of 8 bytes from the net. |
| 171 | */ |
| 172 | if ((num > MAXWRITE) || (num < 0)) /* error */ |
| 173 | return(-1); |
| 174 | rnum=(num < 8)?8:((num+7)/8*8); |
| 175 | |
| 176 | net_num=0; |
| 177 | while (net_num < rnum) |
| 178 | { |
| 179 | #ifndef OPENSSL_SYS_WIN32 |
| 180 | i=read(fd,(void *)&(net[net_num]),rnum-net_num); |
| 181 | #else |
| 182 | i=_read(fd,(void *)&(net[net_num]),rnum-net_num); |
| 183 | #endif |
| 184 | #ifdef EINTR |
| 185 | if ((i == -1) && (errno == EINTR)) continue; |
| 186 | #endif |
| 187 | if (i <= 0) return(0); |
| 188 | net_num+=i; |
| 189 | } |
| 190 | |
| 191 | /* Check if there will be data left over. */ |
| 192 | if (len < num) |
| 193 | { |
| 194 | if (DES_rw_mode & DES_PCBC_MODE) |
| 195 | DES_pcbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT); |
| 196 | else |
| 197 | DES_cbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT); |
| 198 | memcpy(buf,unnet,len); |
| 199 | unnet_start=len; |
| 200 | unnet_left=num-len; |
| 201 | |
| 202 | /* The following line is done because we return num |
| 203 | * as the number of bytes read. */ |
| 204 | num=len; |
| 205 | } |
| 206 | else |
| 207 | { |
| 208 | /* >output is a multiple of 8 byes, if len < rnum |
| 209 | * >we must be careful. The user must be aware that this |
| 210 | * >routine will write more bytes than he asked for. |
| 211 | * >The length of the buffer must be correct. |
| 212 | * FIXED - Should be ok now 18-9-90 - eay */ |
| 213 | if (len < rnum) |
| 214 | { |
| 215 | |
| 216 | if (DES_rw_mode & DES_PCBC_MODE) |
| 217 | DES_pcbc_encrypt(net,tmpbuf,num,sched,iv, |
| 218 | DES_DECRYPT); |
| 219 | else |
| 220 | DES_cbc_encrypt(net,tmpbuf,num,sched,iv, |
| 221 | DES_DECRYPT); |
| 222 | |
| 223 | /* eay 26/08/92 fix a bug that returned more |
| 224 | * bytes than you asked for (returned len bytes :-( */ |
| 225 | memcpy(buf,tmpbuf,num); |
| 226 | } |
| 227 | else |
| 228 | { |
| 229 | if (DES_rw_mode & DES_PCBC_MODE) |
| 230 | DES_pcbc_encrypt(net,buf,num,sched,iv, |
| 231 | DES_DECRYPT); |
| 232 | else |
| 233 | DES_cbc_encrypt(net,buf,num,sched,iv, |
| 234 | DES_DECRYPT); |
| 235 | } |
| 236 | } |
| 237 | return num; |
| 238 | #endif /* OPENSSL_NO_POSIX_IO */ |
| 239 | } |
| 240 | |