Remove not needed void casts.
[dragonfly.git] / bin / ed / cbc.c
CommitLineData
984263bc
MD
1/* cbc.c: This file contains the encryption routines for the ed line editor */
2/*-
3 * Copyright (c) 1993 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * Copyright (c) 1993 Andrew Moore, Talke Studio.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * from: @(#)bdes.c 5.5 (Berkeley) 6/27/91
1de703da
MD
38 *
39 * @(#)cbc.c,v 1.2 1994/02/01 00:34:36 alm Exp
40 * $FreeBSD: src/bin/ed/cbc.c,v 1.12.2.1 2001/07/04 22:32:18 kris Exp $
57fed2af 41 * $DragonFly: src/bin/ed/cbc.c,v 1.6 2004/11/07 20:54:51 eirikn Exp $
984263bc
MD
42 */
43
984263bc
MD
44#include <sys/types.h>
45#include <errno.h>
46#include <pwd.h>
47#ifdef DES
48#include <time.h>
49#endif
50
51#include "ed.h"
52
53
54/*
55 * BSD and System V systems offer special library calls that do
56 * block move_liness and fills, so if possible we take advantage of them
57 */
58#define MEMCPY(dest,src,len) memcpy((dest),(src),(len))
59#define MEMZERO(dest,len) memset((dest), 0, (len))
60
61/* Hide the calls to the primitive encryption routines. */
62#define DES_KEY(buf) \
63 if (des_setkey(buf)) \
64 des_error("des_setkey");
65#define DES_XFORM(buf) \
66 if (des_cipher(buf, buf, 0L, (inverse ? -1 : 1))) \
67 des_error("des_cipher");
68
69/*
70 * read/write - no error checking
71 */
72#define READ(buf, n, fp) fread(buf, sizeof(char), n, fp)
73#define WRITE(buf, n, fp) fwrite(buf, sizeof(char), n, fp)
74
75/*
76 * some things to make references easier
77 */
78typedef char Desbuf[8];
79#define CHAR(x,i) (x[i])
80#define UCHAR(x,i) (x[i])
81#define BUFFER(x) (x)
82#define UBUFFER(x) (x)
83
84/*
85 * global variables and related macros
86 */
87
88enum { /* encrypt, decrypt, authenticate */
89 MODE_ENCRYPT, MODE_DECRYPT, MODE_AUTHENTICATE
90} mode = MODE_ENCRYPT;
91
92Desbuf ivec; /* initialization vector */
93Desbuf pvec; /* padding vector */
94char bits[] = { /* used to extract bits from a char */
95 '\200', '\100', '\040', '\020', '\010', '\004', '\002', '\001'
96};
97int pflag; /* 1 to preserve parity bits */
98
c443019b 99char des_buf[8]; /* shared buffer for get_des_char/put_des_char */
984263bc
MD
100int des_ct = 0; /* count for get_des_char/put_des_char */
101int des_n = 0; /* index for put_des_char/get_des_char */
102
103
104/* init_des_cipher: initialize DES */
105void
b5744197 106init_des_cipher(void)
984263bc
MD
107{
108#ifdef DES
109 int i;
110
111 des_ct = des_n = 0;
112
113 /* initialize the initialization vector */
114 MEMZERO(ivec, 8);
115
116 /* initialize the padding vector */
117 for (i = 0; i < 8; i++)
118 CHAR(pvec, i) = (char) (arc4random() % 256);
119#endif
120}
121
122
123/* get_des_char: return next char in an encrypted file */
124int
b5744197 125get_des_char(FILE *fp)
984263bc
MD
126{
127#ifdef DES
128 if (des_n >= des_ct) {
129 des_n = 0;
130 des_ct = cbc_decode(des_buf, fp);
131 }
c443019b 132 return (des_ct > 0) ? (unsigned char)des_buf[des_n++] : EOF;
984263bc
MD
133#else
134 return (getc(fp));
135#endif
136}
137
138
139/* put_des_char: write a char to an encrypted file; return char written */
140int
b5744197 141put_des_char(int c, FILE *fp)
984263bc
MD
142{
143#ifdef DES
144 if (des_n == sizeof des_buf) {
145 des_ct = cbc_encode(des_buf, des_n, fp);
146 des_n = 0;
147 }
c443019b 148 return (des_ct >= 0) ? ((unsigned char)des_buf[des_n++] = c) : EOF;
984263bc
MD
149#else
150 return (fputc(c, fp));
151#endif
152}
153
154
155/* flush_des_file: flush an encrypted file's output; return status */
156int
b5744197 157flush_des_file(FILE *fp)
984263bc
MD
158{
159#ifdef DES
160 if (des_n == sizeof des_buf) {
161 des_ct = cbc_encode(des_buf, des_n, fp);
162 des_n = 0;
163 }
164 return (des_ct >= 0 && cbc_encode(des_buf, des_n, fp) >= 0) ? 0 : EOF;
165#else
166 return (fflush(fp));
167#endif
168}
169
170#ifdef DES
171/*
172 * get keyword from tty or stdin
173 */
174int
b5744197 175get_keyword(void)
984263bc 176{
86a586bb 177 char *p; /* used to obtain the key */
984263bc
MD
178 Desbuf msgbuf; /* I/O buffer */
179
180 /*
181 * get the key
182 */
183 if (*(p = getpass("Enter key: "))) {
184
185 /*
186 * copy it, nul-padded, into the key area
187 */
188 expand_des_key(BUFFER(msgbuf), p);
189 MEMZERO(p, _PASSWORD_LEN);
190 set_des_key(msgbuf);
191 MEMZERO(msgbuf, sizeof msgbuf);
192 return 1;
193 }
194 return 0;
195}
196
197
198/*
199 * print a warning message and, possibly, terminate
200 */
201void
c443019b 202des_error(const char *s)
984263bc 203{
57fed2af 204 sprintf(errmsg, "%s", s ? s : strerror(errno));
984263bc
MD
205}
206
207/*
208 * map a hex character to an integer
209 */
210int
b5744197 211hex_to_binary(int c, int radix)
984263bc
MD
212{
213 switch(c) {
214 case '0': return(0x0);
215 case '1': return(0x1);
216 case '2': return(radix > 2 ? 0x2 : -1);
217 case '3': return(radix > 3 ? 0x3 : -1);
218 case '4': return(radix > 4 ? 0x4 : -1);
219 case '5': return(radix > 5 ? 0x5 : -1);
220 case '6': return(radix > 6 ? 0x6 : -1);
221 case '7': return(radix > 7 ? 0x7 : -1);
222 case '8': return(radix > 8 ? 0x8 : -1);
223 case '9': return(radix > 9 ? 0x9 : -1);
224 case 'A': case 'a': return(radix > 10 ? 0xa : -1);
225 case 'B': case 'b': return(radix > 11 ? 0xb : -1);
226 case 'C': case 'c': return(radix > 12 ? 0xc : -1);
227 case 'D': case 'd': return(radix > 13 ? 0xd : -1);
228 case 'E': case 'e': return(radix > 14 ? 0xe : -1);
229 case 'F': case 'f': return(radix > 15 ? 0xf : -1);
230 }
231 /*
232 * invalid character
233 */
234 return(-1);
235}
236
237/*
238 * convert the key to a bit pattern
239 */
240void
c443019b 241expand_des_key(char *obuf, char *inbuf)
984263bc 242{
86a586bb 243 int i, j; /* counter in a for loop */
984263bc
MD
244 int nbuf[64]; /* used for hex/key translation */
245
246 /*
247 * leading '0x' or '0X' == hex key
248 */
c443019b
CP
249 if (inbuf[0] == '0' && (inbuf[1] == 'x' || inbuf[1] == 'X')) {
250 inbuf = &inbuf[2];
984263bc
MD
251 /*
252 * now translate it, bombing on any illegal hex digit
253 */
c443019b
CP
254 for (i = 0; inbuf[i] && i < 16; i++)
255 if ((nbuf[i] = hex_to_binary((int) inbuf[i], 16)) == -1)
984263bc
MD
256 des_error("bad hex digit in key");
257 while (i < 16)
258 nbuf[i++] = 0;
259 for (i = 0; i < 8; i++)
260 obuf[i] =
261 ((nbuf[2*i]&0xf)<<4) | (nbuf[2*i+1]&0xf);
262 /* preserve parity bits */
263 pflag = 1;
264 return;
265 }
266 /*
267 * leading '0b' or '0B' == binary key
268 */
c443019b
CP
269 if (inbuf[0] == '0' && (inbuf[1] == 'b' || inbuf[1] == 'B')) {
270 inbuf = &inbuf[2];
984263bc
MD
271 /*
272 * now translate it, bombing on any illegal binary digit
273 */
c443019b
CP
274 for (i = 0; inbuf[i] && i < 16; i++)
275 if ((nbuf[i] = hex_to_binary((int) inbuf[i], 2)) == -1)
984263bc
MD
276 des_error("bad binary digit in key");
277 while (i < 64)
278 nbuf[i++] = 0;
279 for (i = 0; i < 8; i++)
280 for (j = 0; j < 8; j++)
281 obuf[i] = (obuf[i]<<1)|nbuf[8*i+j];
282 /* preserve parity bits */
283 pflag = 1;
284 return;
285 }
286 /*
287 * no special leader -- ASCII
288 */
57fed2af 289 strncpy(obuf, inbuf, 8);
984263bc
MD
290}
291
292/*****************
293 * DES FUNCTIONS *
294 *****************/
295/*
296 * This sets the DES key and (if you're using the deszip version)
297 * the direction of the transformation. This uses the Sun
298 * to map the 64-bit key onto the 56 bits that the key schedule
299 * generation routines use: the old way, which just uses the user-
300 * supplied 64 bits as is, and the new way, which resets the parity
301 * bit to be the same as the low-order bit in each character. The
302 * new way generates a greater variety of key schedules, since many
303 * systems set the parity (high) bit of each character to 0, and the
304 * DES ignores the low order bit of each character.
305 */
306void
b5744197 307set_des_key(Desbuf buf)
984263bc 308{
86a586bb
LF
309 int i, j; /* counter in a for loop */
310 int par; /* parity counter */
984263bc
MD
311
312 /*
313 * if the parity is not preserved, flip it
314 */
315 if (!pflag) {
316 for (i = 0; i < 8; i++) {
317 par = 0;
318 for (j = 1; j < 8; j++)
319 if ((bits[j]&UCHAR(buf, i)) != 0)
320 par++;
321 if ((par&01) == 01)
322 UCHAR(buf, i) = UCHAR(buf, i)&0177;
323 else
324 UCHAR(buf, i) = (UCHAR(buf, i)&0177)|0200;
325 }
326 }
327
328 DES_KEY(UBUFFER(buf));
329}
330
331
332/*
333 * This encrypts using the Cipher Block Chaining mode of DES
334 */
335int
b5744197 336cbc_encode(char *msgbuf, int n, FILE *fp)
984263bc
MD
337{
338 int inverse = 0; /* 0 to encrypt, 1 to decrypt */
339
340 /*
341 * do the transformation
342 */
343 if (n == 8) {
344 for (n = 0; n < 8; n++)
345 CHAR(msgbuf, n) ^= CHAR(ivec, n);
346 DES_XFORM(UBUFFER(msgbuf));
347 MEMCPY(BUFFER(ivec), BUFFER(msgbuf), 8);
348 return WRITE(BUFFER(msgbuf), 8, fp);
349 }
350 /*
351 * at EOF or last block -- in either case, the last byte contains
352 * the character representation of the number of bytes in it
353 */
354/*
355 MEMZERO(msgbuf + n, 8 - n);
356*/
357 /*
358 * Pad the last block randomly
359 */
57fed2af 360 MEMCPY(BUFFER(msgbuf + n), BUFFER(pvec), 8 - n);
984263bc
MD
361 CHAR(msgbuf, 7) = n;
362 for (n = 0; n < 8; n++)
363 CHAR(msgbuf, n) ^= CHAR(ivec, n);
364 DES_XFORM(UBUFFER(msgbuf));
365 return WRITE(BUFFER(msgbuf), 8, fp);
366}
367
368/*
369 * This decrypts using the Cipher Block Chaining mode of DES
370 */
371int
b5744197 372cbc_decode(char *msgbuf, FILE *fp)
984263bc 373{
c443019b 374 Desbuf inbuf; /* temp buffer for initialization vector */
86a586bb
LF
375 int n; /* number of bytes actually read */
376 int c; /* used to test for EOF */
984263bc
MD
377 int inverse = 1; /* 0 to encrypt, 1 to decrypt */
378
379 if ((n = READ(BUFFER(msgbuf), 8, fp)) == 8) {
380 /*
381 * do the transformation
382 */
c443019b 383 MEMCPY(BUFFER(inbuf), BUFFER(msgbuf), 8);
984263bc
MD
384 DES_XFORM(UBUFFER(msgbuf));
385 for (c = 0; c < 8; c++)
386 UCHAR(msgbuf, c) ^= UCHAR(ivec, c);
c443019b 387 MEMCPY(BUFFER(ivec), BUFFER(inbuf), 8);
984263bc
MD
388 /*
389 * if the last one, handle it specially
390 */
391 if ((c = fgetc(fp)) == EOF) {
392 n = CHAR(msgbuf, 7);
393 if (n < 0 || n > 7) {
394 des_error("decryption failed (block corrupted)");
395 return EOF;
396 }
397 } else
57fed2af 398 ungetc(c, fp);
984263bc
MD
399 return n;
400 }
401 if (n > 0)
402 des_error("decryption failed (incomplete block)");
403 else if (n < 0)
404 des_error("cannot read file");
405 return EOF;
406}
407#endif /* DES */