Annotation of src/usr.bin/rlogin/des_rw.c, Revision 1.7
1.7 ! provos 1: /* $OpenBSD: des_rw.c,v 1.6 1997/06/24 01:51:13 dgregor Exp $ */
1.1 deraadt 2: /* $NetBSD: des_rw.c,v 1.2 1995/03/21 07:58:30 cgd Exp $ */
3:
4: /*-
5: * Copyright (c) 1989, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: * 3. All advertising materials mentioning features or use of this software
17: * must display the following acknowledgement:
18: * This product includes software developed by the University of
19: * California, Berkeley and its contributors.
20: * 4. Neither the name of the University nor the names of its contributors
21: * may be used to endorse or promote products derived from this software
22: * without specific prior written permission.
23: *
24: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34: * SUCH DAMAGE.
35: */
36:
37: #ifndef lint
38: #if 0
39: static char sccsid[] = "@(#)des_rw.c 8.1 (Berkeley) 6/6/93";
40: #else
1.7 ! provos 41: static char rcsid[] = "$OpenBSD: des_rw.c,v 1.6 1997/06/24 01:51:13 dgregor Exp $";
1.1 deraadt 42: #endif
43: #endif /* not lint */
44:
45: #ifdef KERBEROS
46: #include <sys/param.h>
47:
1.7 ! provos 48: #include <des.h>
1.1 deraadt 49: #include <kerberosIV/krb.h>
50:
51: #include <stdlib.h>
52: #include <string.h>
53: #include <time.h>
54: #include <unistd.h>
55:
1.3 tholo 56: static unsigned char des_inbuf[10240], storage[10240], *store_ptr;
1.5 mickey 57: static des_cblock *key;
58: static des_key_schedule *key_schedule;
1.1 deraadt 59:
60: /*
61: * NB: These routines will not function properly if NBIO
62: * is set
63: */
64:
65: /*
66: * des_set_key
67: *
68: * Set des encryption/decryption key for use by the des_read and
69: * des_write routines
70: *
71: * The inkey parameter is actually the DES initial vector,
72: * and the insched is the DES Key unwrapped for faster decryption
73: */
1.3 tholo 74: static int nstored = 0;
1.1 deraadt 75:
1.3 tholo 76: void
77: desrw_set_key(inkey, insched)
1.5 mickey 78: des_cblock *inkey;
79: des_key_schedule*insched;
1.1 deraadt 80: {
81: key = inkey;
1.3 tholo 82: key_schedule = insched;
83: nstored = 0;
1.1 deraadt 84: }
85:
86: void
1.3 tholo 87: desrw_clear_key()
1.1 deraadt 88: {
89: bzero((char *) key, sizeof(C_Block));
90: bzero((char *) key_schedule, sizeof(Key_schedule));
91: }
92:
93:
94: int
95: des_read(fd, buf, len)
96: int fd;
97: register char *buf;
98: int len;
99: {
1.3 tholo 100: long net_len, rd_len;
1.1 deraadt 101: int nreturned = 0;
102:
103: if (nstored >= len) {
104: (void) bcopy(store_ptr, buf, len);
105: store_ptr += len;
106: nstored -= len;
107: return(len);
108: } else if (nstored) {
109: (void) bcopy(store_ptr, buf, nstored);
110: nreturned += nstored;
111: buf += nstored;
112: len -= nstored;
113: nstored = 0;
114: }
115:
116: if (krb_net_read(fd, (char *)&net_len, sizeof(net_len)) !=
117: sizeof(net_len)) {
118: /* XXX can't read enough, pipe
119: must have closed */
120: return(0);
121: }
122: net_len = ntohl(net_len);
123: if (net_len <= 0 || net_len > sizeof(des_inbuf)) {
124: /* preposterous length; assume out-of-sync; only
125: recourse is to close connection, so return 0 */
126: return(0);
127: }
128: /* the writer tells us how much real data we are getting, but
129: we need to read the pad bytes (8-byte boundary) */
130: rd_len = roundup(net_len, 8);
131: if (krb_net_read(fd, (char *)des_inbuf, rd_len) != rd_len) {
132: /* pipe must have closed, return 0 */
133: return(0);
134: }
1.3 tholo 135: (void) des_pcbc_encrypt((des_cblock *)des_inbuf, /* inbuf */
136: (des_cblock *)storage, /* outbuf */
137: rd_len, /* length */
1.5 mickey 138: *key_schedule, /* DES key */
139: key, /* IV */
1.3 tholo 140: DECRYPT); /* direction */
1.1 deraadt 141:
142: if(net_len < 8)
143: store_ptr = storage + 8 - net_len;
144: else
145: store_ptr = storage;
146:
147: nstored = net_len;
148: if (nstored > len) {
149: (void) bcopy(store_ptr, buf, len);
150: nreturned += len;
151: store_ptr += len;
152: nstored -= len;
153: } else {
154: (void) bcopy(store_ptr, buf, nstored);
155: nreturned += nstored;
156: nstored = 0;
157: }
158:
159: return(nreturned);
160: }
161:
1.3 tholo 162: static unsigned char des_outbuf[10240]; /* > longest write */
1.1 deraadt 163:
164: int
165: des_write(fd, buf, len)
166: int fd;
167: char *buf;
168: int len;
169: {
170: static int seeded = 0;
1.3 tholo 171: static char garbage_buf[8];
1.1 deraadt 172: long net_len, garbage;
173:
174: if(len < 8) {
175: if(!seeded) {
176: seeded = 1;
1.6 dgregor 177: srandom((int) time(NULL));
1.1 deraadt 178: }
179: garbage = random();
180: /* insert random garbage */
181: (void) bcopy(&garbage, garbage_buf, MIN(sizeof(long),8));
182: /* this "right-justifies" the data in the buffer */
183: (void) bcopy(buf, garbage_buf + 8 - len, len);
184: }
185: /* pcbc_encrypt outputs in 8-byte (64 bit) increments */
186:
1.3 tholo 187: (void) des_pcbc_encrypt((des_cblock *)((len < 8) ? garbage_buf : buf),
188: (des_cblock *)des_outbuf,
1.1 deraadt 189: (len < 8) ? 8 : len,
1.5 mickey 190: *key_schedule, /* DES key */
191: key, /* IV */
1.1 deraadt 192: ENCRYPT);
193:
194: /* tell the other end the real amount, but send an 8-byte padded
195: packet */
196: net_len = htonl(len);
197: (void) write(fd, &net_len, sizeof(net_len));
198: (void) write(fd, des_outbuf, roundup(len,8));
199: return(len);
200: }
201: #endif /* KERBEROS */
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