1 /* $OpenBSD: enc_writ.c,v 1.14 2015/02/12 03:54:07 jsing Exp $ */
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 <stdio.h>
61 #include <stdlib.h>
62 #include <time.h>
63 
64 #include <openssl/opensslconf.h>
65 
66 #include "des_locl.h"
67 
68 /*
69  * WARNINGS:
70  *
71  *  -  The data format used by DES_enc_write() and DES_enc_read()
72  *     has a cryptographic weakness: When asked to write more
73  *     than MAXWRITE bytes, DES_enc_write will split the data
74  *     into several chunks that are all encrypted
75  *     using the same IV.  So don't use these functions unless you
76  *     are sure you know what you do (in which case you might
77  *     not want to use them anyway).
78  *
79  *  -  This code cannot handle non-blocking sockets.
80  */
81 
DES_enc_write(int fd,const void * _buf,int len,DES_key_schedule * sched,DES_cblock * iv)82 int DES_enc_write(int fd, const void *_buf, int len,
83 		  DES_key_schedule *sched, DES_cblock *iv)
84 	{
85 #ifdef _LIBC
86 	extern unsigned long time();
87 	extern int write();
88 #endif
89 	const unsigned char *buf=_buf;
90 	long rnum;
91 	int i,j,k,outnum;
92 	static unsigned char *outbuf=NULL;
93 	unsigned char shortbuf[8];
94 	unsigned char *p;
95 	const unsigned char *cp;
96 	static int start=1;
97 
98 	if (outbuf == NULL)
99 		{
100 		outbuf=malloc(BSIZE+HDRSIZE);
101 		if (outbuf == NULL) return(-1);
102 		}
103 	/* If we are sending less than 8 bytes, the same char will look
104 	 * the same if we don't pad it out with random bytes */
105 	if (start)
106 		{
107 		start=0;
108 		}
109 
110 	/* lets recurse if we want to send the data in small chunks */
111 	if (len > MAXWRITE)
112 		{
113 		j=0;
114 		for (i=0; i<len; i+=k)
115 			{
116 			k=DES_enc_write(fd,&(buf[i]),
117 				((len-i) > MAXWRITE)?MAXWRITE:(len-i),sched,iv);
118 			if (k < 0)
119 				return(k);
120 			else
121 				j+=k;
122 			}
123 		return(j);
124 		}
125 
126 	/* write length first */
127 	p=outbuf;
128 	l2n(len,p);
129 
130 	/* pad short strings */
131 	if (len < 8)
132 		{
133 		cp=shortbuf;
134 		memcpy(shortbuf,buf,len);
135 		arc4random_buf(shortbuf+len, 8-len);
136 		rnum=8;
137 		}
138 	else
139 		{
140 		cp=buf;
141 		rnum=((len+7)/8*8); /* round up to nearest eight */
142 		}
143 
144 	if (DES_rw_mode & DES_PCBC_MODE)
145 		DES_pcbc_encrypt(cp,&(outbuf[HDRSIZE]),(len<8)?8:len,sched,iv,
146 				 DES_ENCRYPT);
147 	else
148 		DES_cbc_encrypt(cp,&(outbuf[HDRSIZE]),(len<8)?8:len,sched,iv,
149 				DES_ENCRYPT);
150 
151 	/* output */
152 	outnum=rnum+HDRSIZE;
153 
154 	for (j=0; j<outnum; j+=i)
155 		{
156 		/* eay 26/08/92 I was not doing writing from where we
157 		 * got up to. */
158 		i=write(fd,(void *)&(outbuf[j]),outnum-j);
159 		if (i == -1)
160 			{
161 #ifdef EINTR
162 			if (errno == EINTR)
163 				i=0;
164 			else
165 #endif
166 			        /* This is really a bad error - very bad
167 				 * It will stuff-up both ends. */
168 				return(-1);
169 			}
170 		}
171 
172 	return(len);
173 	}
174