1 /* crypto/des/enc_writ.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 <errno.h>
60 #include <time.h>
61 #include <stdio.h>
62 #include "des_locl.h"
63
64 /*
65 * WARNINGS:
66 *
67 * - The data format used by des_enc_write() and des_enc_read()
68 * has a cryptographic weakness: When asked to write more
69 * than MAXWRITE bytes, des_enc_write will split the data
70 * into several chunks that are all encrypted
71 * using the same IV. So don't use these functions unless you
72 * are sure you know what you do (in which case you might
73 * not want to use them anyway).
74 *
75 * - This code cannot handle non-blocking sockets.
76 */
77
des_enc_write(int fd,const void * _buf,int len,des_key_schedule sched,des_cblock * iv)78 int des_enc_write(int fd, const void *_buf, int len,
79 des_key_schedule sched, des_cblock *iv)
80 {
81 #ifdef _LIBC
82 extern unsigned long time();
83 extern int write();
84 #endif
85 const unsigned char *buf=_buf;
86 long rnum;
87 int i,j,k,outnum;
88 static unsigned char *outbuf=NULL;
89 unsigned char shortbuf[8];
90 unsigned char *p;
91 const unsigned char *cp;
92 static int start=1;
93
94 if (outbuf == NULL)
95 {
96 outbuf=OPENSSL_malloc(BSIZE+HDRSIZE);
97 if (outbuf == NULL) return(-1);
98 }
99 /* If we are sending less than 8 bytes, the same char will look
100 * the same if we don't pad it out with random bytes */
101 if (start)
102 {
103 start=0;
104 }
105
106 /* lets recurse if we want to send the data in small chunks */
107 if (len > MAXWRITE)
108 {
109 j=0;
110 for (i=0; i<len; i+=k)
111 {
112 k=des_enc_write(fd,&(buf[i]),
113 ((len-i) > MAXWRITE)?MAXWRITE:(len-i),sched,iv);
114 if (k < 0)
115 return(k);
116 else
117 j+=k;
118 }
119 return(j);
120 }
121
122 /* write length first */
123 p=outbuf;
124 l2n(len,p);
125
126 /* pad short strings */
127 if (len < 8)
128 {
129 cp=shortbuf;
130 memcpy(shortbuf,buf,len);
131 *(u_int32_t *)&shortbuf[0] = arc4random();
132 *(u_int32_t *)&shortbuf[4] = arc4random();
133 rnum=8;
134 }
135 else
136 {
137 cp=buf;
138 rnum=((len+7)/8*8); /* round up to nearest eight */
139 }
140
141 if (des_rw_mode & DES_PCBC_MODE)
142 des_pcbc_encrypt(cp,&(outbuf[HDRSIZE]),(len<8)?8:len,sched,iv,
143 DES_ENCRYPT);
144 else
145 des_cbc_encrypt(cp,&(outbuf[HDRSIZE]),(len<8)?8:len,sched,iv,
146 DES_ENCRYPT);
147
148 /* output */
149 outnum=rnum+HDRSIZE;
150
151 for (j=0; j<outnum; j+=i)
152 {
153 /* eay 26/08/92 I was not doing writing from where we
154 * got up to. */
155 i=write(fd,(void *)&(outbuf[j]),outnum-j);
156 if (i == -1)
157 {
158 #ifdef EINTR
159 if (errno == EINTR)
160 i=0;
161 else
162 #endif
163 /* This is really a bad error - very bad
164 * It will stuff-up both ends. */
165 return(-1);
166 }
167 }
168
169 return(len);
170 }
171