Annotation of src/usr.bin/rsh/des_rw.c, Revision 1.3
1.3 ! deraadt 1: /* $OpenBSD: des_rw.c,v 1.2 2002/07/15 22:11:34 deraadt 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
1.3 ! deraadt 41: static char rcsid[] = "$OpenBSD: des_rw.c,v 1.2 2002/07/15 22:11:34 deraadt Exp $";
1.1 deraadt 42: #endif
43: #endif /* not lint */
44:
45: #ifdef KERBEROS
46: #include <sys/param.h>
47:
48: #include <des.h>
49: #include <kerberosIV/krb.h>
50:
51: #include <stdlib.h>
52: #include <string.h>
53: #include <time.h>
54: #include <unistd.h>
55:
56: void desrw_set_key(des_cblock *, des_key_schedule *);
57: void desrw_clear_key(void);
1.2 deraadt 58: int des_read(int, void *, int);
59: int des_write(int, void *, int);
1.1 deraadt 60:
61: static unsigned char des_inbuf[10240], storage[10240], *store_ptr;
62: static des_cblock *key;
63: static des_key_schedule *key_schedule;
64:
65: /*
66: * NB: These routines will not function properly if NBIO
67: * is set
68: */
69:
70: /*
71: * des_set_key
72: *
73: * Set des encryption/decryption key for use by the des_read and
74: * des_write routines
75: *
76: * The inkey parameter is actually the DES initial vector,
77: * and the insched is the DES Key unwrapped for faster decryption
78: */
79: static int nstored = 0;
80:
81: void
1.3 ! deraadt 82: desrw_set_key(des_cblock *inkey, des_key_schedule *insched)
1.1 deraadt 83: {
84: key = inkey;
85: key_schedule = insched;
86: nstored = 0;
87: }
88:
89: void
1.3 ! deraadt 90: desrw_clear_key(void)
1.1 deraadt 91: {
92: bzero((char *) key, sizeof(C_Block));
93: bzero((char *) key_schedule, sizeof(Key_schedule));
94: }
95:
96:
97: int
1.3 ! deraadt 98: des_read(int fd, void *bp, int len)
1.1 deraadt 99: {
100: long net_len, rd_len;
101: int nreturned = 0;
1.2 deraadt 102: char *buf = bp;
1.1 deraadt 103:
104: if (nstored >= len) {
105: (void) bcopy(store_ptr, buf, len);
106: store_ptr += len;
107: nstored -= len;
108: return(len);
109: } else if (nstored) {
110: (void) bcopy(store_ptr, buf, nstored);
111: nreturned += nstored;
112: buf += nstored;
113: len -= nstored;
114: nstored = 0;
115: }
116:
117: if (krb_net_read(fd, (char *)&net_len, sizeof(net_len)) !=
118: sizeof(net_len)) {
119: /* XXX can't read enough, pipe
120: must have closed */
121: return(0);
122: }
123: net_len = ntohl(net_len);
124: if (net_len <= 0 || net_len > sizeof(des_inbuf)) {
125: /* preposterous length; assume out-of-sync; only
126: recourse is to close connection, so return 0 */
127: return(0);
128: }
129: /* the writer tells us how much real data we are getting, but
130: we need to read the pad bytes (8-byte boundary) */
131: rd_len = roundup(net_len, 8);
132: if (krb_net_read(fd, (char *)des_inbuf, rd_len) != rd_len) {
133: /* pipe must have closed, return 0 */
134: return(0);
135: }
1.3 ! deraadt 136: (void) des_pcbc_encrypt((des_cblock *)des_inbuf,
! 137: (des_cblock *)storage, rd_len, *key_schedule, key, DECRYPT);
1.1 deraadt 138:
139: if(net_len < 8)
140: store_ptr = storage + 8 - net_len;
141: else
142: store_ptr = storage;
143:
144: nstored = net_len;
145: if (nstored > len) {
146: (void) bcopy(store_ptr, buf, len);
147: nreturned += len;
148: store_ptr += len;
149: nstored -= len;
150: } else {
151: (void) bcopy(store_ptr, buf, nstored);
152: nreturned += nstored;
153: nstored = 0;
154: }
155:
156: return(nreturned);
157: }
158:
159: static unsigned char des_outbuf[10240]; /* > longest write */
160:
161: int
1.3 ! deraadt 162: des_write(int fd, void *bp, int len)
1.1 deraadt 163: {
164: static int seeded = 0;
165: static char garbage_buf[8];
166: long net_len, garbage;
1.2 deraadt 167: char *buf = bp;
1.1 deraadt 168:
169: if(len < 8) {
170: if(!seeded) {
171: seeded = 1;
172: srandom((int) time(NULL));
173: }
174: garbage = random();
175: /* insert random garbage */
176: (void) bcopy(&garbage, garbage_buf, MIN(sizeof(long),8));
177: /* this "right-justifies" the data in the buffer */
178: (void) bcopy(buf, garbage_buf + 8 - len, len);
179: }
180: /* pcbc_encrypt outputs in 8-byte (64 bit) increments */
181:
182: (void) des_pcbc_encrypt((des_cblock *)((len < 8) ? garbage_buf : buf),
1.3 ! deraadt 183: (des_cblock *)des_outbuf, (len < 8) ? 8 : len,
! 184: *key_schedule, key, ENCRYPT);
1.1 deraadt 185:
186: /* tell the other end the real amount, but send an 8-byte padded
187: packet */
188: net_len = htonl(len);
189: (void) write(fd, &net_len, sizeof(net_len));
190: (void) write(fd, des_outbuf, roundup(len,8));
191: return(len);
192: }
193: #endif /* KERBEROS */