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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. | |
40720ce3 | 8 | * |
d02b48c6 RE |
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). | |
40720ce3 | 15 | * |
d02b48c6 RE |
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. | |
40720ce3 | 22 | * |
d02b48c6 RE |
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 :-). | |
40720ce3 | 37 | * 4. If you include any Windows specific code (or a derivative thereof) from |
d02b48c6 RE |
38 | * the apps directory (application code) you must include an acknowledgement: |
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
40720ce3 | 40 | * |
d02b48c6 RE |
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. | |
40720ce3 | 52 | * |
d02b48c6 RE |
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. */ | |
40720ce3 MC |
65 | /* |
66 | * extern int errno; | |
67 | */ | |
68 | OPENSSL_IMPLEMENT_GLOBAL(int, DES_rw_mode) = DES_PCBC_MODE; | |
7c0f3d09 | 69 | |
b558c8d5 | 70 | /*- |
7c0f3d09 BM |
71 | * WARNINGS: |
72 | * | |
c2e4f17c | 73 | * - The data format used by DES_enc_write() and DES_enc_read() |
7c0f3d09 | 74 | * has a cryptographic weakness: When asked to write more |
c2e4f17c | 75 | * than MAXWRITE bytes, DES_enc_write will split the data |
7c0f3d09 BM |
76 | * into several chunks that are all encrypted |
77 | * using the same IV. So don't use these functions unless you | |
78 | * are sure you know what you do (in which case you might | |
79 | * not want to use them anyway). | |
80 | * | |
81 | * - This code cannot handle non-blocking sockets. | |
82 | * | |
83 | * - This function uses an internal state and thus cannot be | |
84 | * used on multiple files. | |
85 | */ | |
86 | ||
c2e4f17c | 87 | int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched, |
40720ce3 MC |
88 | DES_cblock *iv) |
89 | { | |
90 | /* data to be unencrypted */ | |
91 | int net_num = 0; | |
92 | static unsigned char *net = NULL; | |
93 | /* | |
94 | * extra unencrypted data for when a block of 100 comes in but is | |
95 | * des_read one byte at a time. | |
96 | */ | |
97 | static unsigned char *unnet = NULL; | |
98 | static int unnet_start = 0; | |
99 | static int unnet_left = 0; | |
100 | static unsigned char *tmpbuf = NULL; | |
101 | int i; | |
102 | long num = 0, rnum; | |
103 | unsigned char *p; | |
104 | ||
105 | if (tmpbuf == NULL) { | |
106 | tmpbuf = OPENSSL_malloc(BSIZE); | |
107 | if (tmpbuf == NULL) | |
108 | return (-1); | |
109 | } | |
110 | if (net == NULL) { | |
111 | net = OPENSSL_malloc(BSIZE); | |
112 | if (net == NULL) | |
113 | return (-1); | |
114 | } | |
115 | if (unnet == NULL) { | |
116 | unnet = OPENSSL_malloc(BSIZE); | |
117 | if (unnet == NULL) | |
118 | return (-1); | |
119 | } | |
120 | /* left over data from last decrypt */ | |
121 | if (unnet_left != 0) { | |
122 | if (unnet_left < len) { | |
123 | /* | |
124 | * we still still need more data but will return with the number | |
125 | * of bytes we have - should always check the return value | |
126 | */ | |
127 | memcpy(buf, &(unnet[unnet_start]), unnet_left); | |
128 | /* | |
129 | * eay 26/08/92 I had the next 2 lines reversed :-( | |
130 | */ | |
131 | i = unnet_left; | |
132 | unnet_start = unnet_left = 0; | |
133 | } else { | |
134 | memcpy(buf, &(unnet[unnet_start]), len); | |
135 | unnet_start += len; | |
136 | unnet_left -= len; | |
137 | i = len; | |
138 | } | |
139 | return (i); | |
140 | } | |
141 | ||
142 | /* We need to get more data. */ | |
143 | if (len > MAXWRITE) | |
144 | len = MAXWRITE; | |
145 | ||
146 | /* first - get the length */ | |
147 | while (net_num < HDRSIZE) { | |
f17c4561 | 148 | #ifndef _WIN32 |
40720ce3 | 149 | i = read(fd, (void *)&(net[net_num]), HDRSIZE - net_num); |
f17c4561 | 150 | #else |
40720ce3 | 151 | i = _read(fd, (void *)&(net[net_num]), HDRSIZE - net_num); |
f17c4561 | 152 | #endif |
58964a49 | 153 | #ifdef EINTR |
40720ce3 MC |
154 | if ((i == -1) && (errno == EINTR)) |
155 | continue; | |
58964a49 | 156 | #endif |
40720ce3 MC |
157 | if (i <= 0) |
158 | return (0); | |
159 | net_num += i; | |
160 | } | |
161 | ||
162 | /* we now have at net_num bytes in net */ | |
163 | p = net; | |
164 | /* num=0; */ | |
165 | n2l(p, num); | |
166 | /* | |
167 | * num should be rounded up to the next group of eight we make sure that | |
168 | * we have read a multiple of 8 bytes from the net. | |
169 | */ | |
170 | if ((num > MAXWRITE) || (num < 0)) /* error */ | |
171 | return (-1); | |
172 | rnum = (num < 8) ? 8 : ((num + 7) / 8 * 8); | |
173 | ||
174 | net_num = 0; | |
175 | while (net_num < rnum) { | |
176 | i = read(fd, (void *)&(net[net_num]), rnum - net_num); | |
58964a49 | 177 | #ifdef EINTR |
40720ce3 MC |
178 | if ((i == -1) && (errno == EINTR)) |
179 | continue; | |
58964a49 | 180 | #endif |
40720ce3 MC |
181 | if (i <= 0) |
182 | return (0); | |
183 | net_num += i; | |
184 | } | |
185 | ||
186 | /* Check if there will be data left over. */ | |
187 | if (len < num) { | |
188 | if (DES_rw_mode & DES_PCBC_MODE) | |
189 | DES_pcbc_encrypt(net, unnet, num, sched, iv, DES_DECRYPT); | |
190 | else | |
191 | DES_cbc_encrypt(net, unnet, num, sched, iv, DES_DECRYPT); | |
192 | memcpy(buf, unnet, len); | |
193 | unnet_start = len; | |
194 | unnet_left = num - len; | |
195 | ||
196 | /* | |
197 | * The following line is done because we return num as the number of | |
198 | * bytes read. | |
199 | */ | |
200 | num = len; | |
201 | } else { | |
202 | /*- | |
203 | * >output is a multiple of 8 byes, if len < rnum | |
204 | * >we must be careful. The user must be aware that this | |
205 | * >routine will write more bytes than he asked for. | |
206 | * >The length of the buffer must be correct. | |
207 | * FIXED - Should be ok now 18-9-90 - eay */ | |
208 | if (len < rnum) { | |
209 | ||
210 | if (DES_rw_mode & DES_PCBC_MODE) | |
211 | DES_pcbc_encrypt(net, tmpbuf, num, sched, iv, DES_DECRYPT); | |
212 | else | |
213 | DES_cbc_encrypt(net, tmpbuf, num, sched, iv, DES_DECRYPT); | |
214 | ||
215 | /* | |
216 | * eay 26/08/92 fix a bug that returned more bytes than you asked | |
217 | * for (returned len bytes :-( | |
218 | */ | |
219 | memcpy(buf, tmpbuf, num); | |
220 | } else { | |
221 | if (DES_rw_mode & DES_PCBC_MODE) | |
222 | DES_pcbc_encrypt(net, buf, num, sched, iv, DES_DECRYPT); | |
223 | else | |
224 | DES_cbc_encrypt(net, buf, num, sched, iv, DES_DECRYPT); | |
225 | } | |
226 | } | |
227 | return num; | |
228 | } |