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d02b48c6 | 1 | /* crypto/des/enc_read.c */ |
58964a49 | 2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
d02b48c6 RE |
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> | |
199d59e5 | 61 | #include "cryptlib.h" |
d02b48c6 RE |
62 | #include "des_locl.h" |
63 | ||
64 | /* This has some uglies in it but it works - even over sockets. */ | |
65 | /*extern int errno;*/ | |
e4317d20 | 66 | OPENSSL_IMPLEMENT_GLOBAL(int,DES_rw_mode,DES_PCBC_MODE) |
d02b48c6 | 67 | |
7c0f3d09 | 68 | |
1d97c843 | 69 | /*- |
7c0f3d09 BM |
70 | * WARNINGS: |
71 | * | |
c2e4f17c | 72 | * - The data format used by DES_enc_write() and DES_enc_read() |
7c0f3d09 | 73 | * has a cryptographic weakness: When asked to write more |
c2e4f17c | 74 | * than MAXWRITE bytes, DES_enc_write will split the data |
7c0f3d09 BM |
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 | ||
c2e4f17c RL |
87 | int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched, |
88 | DES_cblock *iv) | |
d02b48c6 | 89 | { |
1715e488 AP |
90 | #if defined(OPENSSL_NO_POSIX_IO) |
91 | return(0); | |
92 | #else | |
d02b48c6 RE |
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. */ | |
95dc05bc | 99 | static unsigned char *unnet=NULL; |
d02b48c6 RE |
100 | static int unnet_start=0; |
101 | static int unnet_left=0; | |
95dc05bc | 102 | static unsigned char *tmpbuf=NULL; |
d02b48c6 RE |
103 | int i; |
104 | long num=0,rnum; | |
105 | unsigned char *p; | |
106 | ||
107 | if (tmpbuf == NULL) | |
108 | { | |
26a3a48d | 109 | tmpbuf=OPENSSL_malloc(BSIZE); |
d02b48c6 RE |
110 | if (tmpbuf == NULL) return(-1); |
111 | } | |
112 | if (net == NULL) | |
113 | { | |
26a3a48d | 114 | net=OPENSSL_malloc(BSIZE); |
d02b48c6 RE |
115 | if (net == NULL) return(-1); |
116 | } | |
117 | if (unnet == NULL) | |
118 | { | |
26a3a48d | 119 | unnet=OPENSSL_malloc(BSIZE); |
d02b48c6 RE |
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]), | |
61f5b6f3 | 131 | unnet_left); |
d02b48c6 RE |
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 | { | |
61f5b6f3 | 139 | memcpy(buf,&(unnet[unnet_start]),len); |
d02b48c6 RE |
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 | { | |
14023fe3 | 153 | #ifndef OPENSSL_SYS_WIN32 |
17f389bb | 154 | i=read(fd,(void *)&(net[net_num]),HDRSIZE-net_num); |
a5910673 DSH |
155 | #else |
156 | i=_read(fd,(void *)&(net[net_num]),HDRSIZE-net_num); | |
157 | #endif | |
58964a49 | 158 | #ifdef EINTR |
d02b48c6 | 159 | if ((i == -1) && (errno == EINTR)) continue; |
58964a49 | 160 | #endif |
d02b48c6 RE |
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 | { | |
0089a9df | 179 | #ifndef OPENSSL_SYS_WIN32 |
17f389bb | 180 | i=read(fd,(void *)&(net[net_num]),rnum-net_num); |
0089a9df DSH |
181 | #else |
182 | i=_read(fd,(void *)&(net[net_num]),rnum-net_num); | |
183 | #endif | |
58964a49 | 184 | #ifdef EINTR |
d02b48c6 | 185 | if ((i == -1) && (errno == EINTR)) continue; |
58964a49 | 186 | #endif |
d02b48c6 RE |
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 | { | |
c2e4f17c RL |
194 | if (DES_rw_mode & DES_PCBC_MODE) |
195 | DES_pcbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT); | |
d02b48c6 | 196 | else |
c2e4f17c | 197 | DES_cbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT); |
61f5b6f3 | 198 | memcpy(buf,unnet,len); |
d02b48c6 | 199 | unnet_start=len; |
61f5b6f3 | 200 | unnet_left=num-len; |
d02b48c6 RE |
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 | { | |
c80fd6b2 MC |
208 | /*- |
209 | * >output is a multiple of 8 byes, if len < rnum | |
d02b48c6 RE |
210 | * >we must be careful. The user must be aware that this |
211 | * >routine will write more bytes than he asked for. | |
212 | * >The length of the buffer must be correct. | |
213 | * FIXED - Should be ok now 18-9-90 - eay */ | |
214 | if (len < rnum) | |
215 | { | |
216 | ||
c2e4f17c RL |
217 | if (DES_rw_mode & DES_PCBC_MODE) |
218 | DES_pcbc_encrypt(net,tmpbuf,num,sched,iv, | |
4e31df2c | 219 | DES_DECRYPT); |
d02b48c6 | 220 | else |
c2e4f17c | 221 | DES_cbc_encrypt(net,tmpbuf,num,sched,iv, |
4e31df2c | 222 | DES_DECRYPT); |
d02b48c6 RE |
223 | |
224 | /* eay 26/08/92 fix a bug that returned more | |
225 | * bytes than you asked for (returned len bytes :-( */ | |
61f5b6f3 | 226 | memcpy(buf,tmpbuf,num); |
d02b48c6 RE |
227 | } |
228 | else | |
229 | { | |
c2e4f17c RL |
230 | if (DES_rw_mode & DES_PCBC_MODE) |
231 | DES_pcbc_encrypt(net,buf,num,sched,iv, | |
cb145b99 | 232 | DES_DECRYPT); |
d02b48c6 | 233 | else |
c2e4f17c | 234 | DES_cbc_encrypt(net,buf,num,sched,iv, |
cb145b99 | 235 | DES_DECRYPT); |
d02b48c6 RE |
236 | } |
237 | } | |
61f5b6f3 | 238 | return num; |
1715e488 | 239 | #endif /* OPENSSL_NO_POSIX_IO */ |
d02b48c6 RE |
240 | } |
241 |