1 /* crypto/des/enc_read.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
63 /* This has some uglies in it but it works - even over sockets. */
65 int des_rw_mode=DES_PCBC_MODE;
67 int des_enc_read(fd, buf, len, sched, iv)
71 des_key_schedule sched;
74 /* data to be unencrypted */
76 static unsigned char *net=NULL;
77 /* extra unencrypted data
78 * for when a block of 100 comes in but is des_read one byte at
80 static char *unnet=NULL;
81 static int unnet_start=0;
82 static int unnet_left=0;
83 static char *tmpbuf=NULL;
90 tmpbuf=(char *)malloc(BSIZE);
91 if (tmpbuf == NULL) return(-1);
95 net=(unsigned char *)malloc(BSIZE);
96 if (net == NULL) return(-1);
100 unnet=(char *)malloc(BSIZE);
101 if (unnet == NULL) return(-1);
103 /* left over data from last decrypt */
106 if (unnet_left < len)
108 /* we still still need more data but will return
109 * with the number of bytes we have - should always
110 * check the return value */
111 memcpy(buf,&(unnet[unnet_start]),
112 (unsigned int)unnet_left);
113 /* eay 26/08/92 I had the next 2 lines
116 unnet_start=unnet_left=0;
120 memcpy(buf,&(unnet[unnet_start]),(unsigned int)len);
128 /* We need to get more data. */
129 if (len > MAXWRITE) len=MAXWRITE;
131 /* first - get the length */
132 while (net_num < HDRSIZE)
134 i=read(fd,&(net[net_num]),(unsigned int)HDRSIZE-net_num);
136 if ((i == -1) && (errno == EINTR)) continue;
138 if (i <= 0) return(0);
142 /* we now have at net_num bytes in net */
146 /* num should be rounded up to the next group of eight
147 * we make sure that we have read a multiple of 8 bytes from the net.
149 if ((num > MAXWRITE) || (num < 0)) /* error */
151 rnum=(num < 8)?8:((num+7)/8*8);
154 while (net_num < rnum)
156 i=read(fd,&(net[net_num]),(unsigned int)rnum-net_num);
158 if ((i == -1) && (errno == EINTR)) continue;
160 if (i <= 0) return(0);
164 /* Check if there will be data left over. */
167 if (des_rw_mode & DES_PCBC_MODE)
168 des_pcbc_encrypt((des_cblock *)net,(des_cblock *)unnet,
169 num,sched,iv,DES_DECRYPT);
171 des_cbc_encrypt((des_cblock *)net,(des_cblock *)unnet,
172 num,sched,iv,DES_DECRYPT);
173 memcpy(buf,unnet,(unsigned int)len);
175 unnet_left=(int)num-len;
177 /* The following line is done because we return num
178 * as the number of bytes read. */
183 /* >output is a multiple of 8 byes, if len < rnum
184 * >we must be careful. The user must be aware that this
185 * >routine will write more bytes than he asked for.
186 * >The length of the buffer must be correct.
187 * FIXED - Should be ok now 18-9-90 - eay */
191 if (des_rw_mode & DES_PCBC_MODE)
192 des_pcbc_encrypt((des_cblock *)net,
193 (des_cblock *)tmpbuf,
194 num,sched,iv,DES_DECRYPT);
196 des_cbc_encrypt((des_cblock *)net,
197 (des_cblock *)tmpbuf,
198 num,sched,iv,DES_DECRYPT);
200 /* eay 26/08/92 fix a bug that returned more
201 * bytes than you asked for (returned len bytes :-( */
202 memcpy(buf,tmpbuf,(unsigned int)num);
206 if (des_rw_mode & DES_PCBC_MODE)
207 des_pcbc_encrypt((des_cblock *)net,
208 (des_cblock *)buf,num,sched,iv,
211 des_cbc_encrypt((des_cblock *)net,
212 (des_cblock *)buf,num,sched,iv,