1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
/* lib/des/enc_read.c */
/* Copyright (C) 1995 Eric Young (eay@mincom.oz.au)
* All rights reserved.
*
* This file is part of an SSL implementation written
* by Eric Young (eay@mincom.oz.au).
* The implementation was written so as to conform with Netscapes SSL
* specification. This library and applications are
* FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
* as long as the following conditions are aheared to.
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed. If this code is used in a product,
* Eric Young should be given attribution as the author of the parts used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Eric Young (eay@mincom.oz.au)
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include <stdio.h>
#include <errno.h>
#include "des_locl.h"
/* This has some uglies in it but it works - even over sockets. */
extern int errno;
int des_rw_mode=DES_PCBC_MODE;
int des_enc_read(fd, buf, len, sched, iv)
int fd;
char *buf;
int len;
des_key_schedule sched;
des_cblock (*iv);
{
/* data to be unencrypted */
int net_num=0;
unsigned char net[BSIZE];
/* extra unencrypted data
* for when a block of 100 comes in but is des_read one byte at
* a time. */
static char unnet[BSIZE];
static int unnet_start=0;
static int unnet_left=0;
int i;
long num=0,rnum;
unsigned char *p;
/* left over data from last decrypt */
if (unnet_left != 0)
{
if (unnet_left < len)
{
/* we still still need more data but will return
* with the number of bytes we have - should always
* check the return value */
memcpy(buf,&(unnet[unnet_start]),
(unsigned int)unnet_left);
/* eay 26/08/92 I had the next 2 lines
* reversed :-( */
i=unnet_left;
unnet_start=unnet_left=0;
}
else
{
memcpy(buf,&(unnet[unnet_start]),(unsigned int)len);
unnet_start+=len;
unnet_left-=len;
i=len;
}
return(i);
}
/* We need to get more data. */
if (len > MAXWRITE) len=MAXWRITE;
/* first - get the length */
net_num=0;
while (net_num < HDRSIZE)
{
i=read(fd,&(net[net_num]),(unsigned int)HDRSIZE-net_num);
if ((i == -1) && (errno == EINTR)) continue;
if (i <= 0) return(0);
net_num+=i;
}
/* we now have at net_num bytes in net */
p=net;
num=0;
n2l(p,num);
/* num should be rounded up to the next group of eight
* we make sure that we have read a multiple of 8 bytes from the net.
*/
if ((num > MAXWRITE) || (num < 0)) /* error */
return(-1);
rnum=(num < 8)?8:((num+7)/8*8);
net_num=0;
while (net_num < rnum)
{
i=read(fd,&(net[net_num]),(unsigned int)rnum-net_num);
if ((i == -1) && (errno == EINTR)) continue;
if (i <= 0) return(0);
net_num+=i;
}
/* Check if there will be data left over. */
if (len < num)
{
if (des_rw_mode & DES_PCBC_MODE)
pcbc_encrypt((des_cblock *)net,(des_cblock *)unnet,
num,sched,iv,DES_DECRYPT);
else
cbc_encrypt((des_cblock *)net,(des_cblock *)unnet,
num,sched,iv,DES_DECRYPT);
memcpy(buf,unnet,(unsigned int)len);
unnet_start=len;
unnet_left=num-len;
/* The following line is done because we return num
* as the number of bytes read. */
num=len;
}
else
{
/* >output is a multiple of 8 byes, if len < rnum
* >we must be careful. The user must be aware that this
* >routine will write more bytes than he asked for.
* >The length of the buffer must be correct.
* FIXED - Should be ok now 18-9-90 - eay */
if (len < rnum)
{
char tmpbuf[BSIZE];
if (des_rw_mode & DES_PCBC_MODE)
pcbc_encrypt((des_cblock *)net,
(des_cblock *)tmpbuf,
num,sched,iv,DES_DECRYPT);
else
cbc_encrypt((des_cblock *)net,
(des_cblock *)tmpbuf,
num,sched,iv,DES_DECRYPT);
/* eay 26/08/92 fix a bug that returned more
* bytes than you asked for (returned len bytes :-( */
memcpy(buf,tmpbuf,(unsigned int)num);
}
else
{
if (des_rw_mode & DES_PCBC_MODE)
pcbc_encrypt((des_cblock *)net,
(des_cblock *)buf,num,sched,iv,
DES_DECRYPT);
else
cbc_encrypt((des_cblock *)net,
(des_cblock *)buf,num,sched,iv,
DES_DECRYPT);
}
}
return(num);
}
|
