1 /* cbc.c: This file contains the encryption routines for the ed line editor */
3 * Copyright (c) 1993 The Regents of the University of California.
6 * Copyright (c) 1993 Andrew Moore, Talke Studio.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
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 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 #include <sys/types.h>
42 #include <openssl/des.h>
43 #define ED_DES_INCLUDES
50 * BSD and System V systems offer special library calls that do
51 * block move_liness and fills, so if possible we take advantage of them
53 #define MEMCPY(dest,src,len) memcpy((dest),(src),(len))
54 #define MEMZERO(dest,len) memset((dest), 0, (len))
56 /* Hide the calls to the primitive encryption routines. */
57 #define DES_XFORM(buf) \
58 DES_ecb_encrypt(buf, buf, &schedule, \
59 inverse ? DES_DECRYPT : DES_ENCRYPT);
62 * read/write - no error checking
64 #define READ(buf, n, fp) fread(buf, sizeof(char), n, fp)
65 #define WRITE(buf, n, fp) fwrite(buf, sizeof(char), n, fp)
68 * global variables and related macros
72 static DES_cblock ivec; /* initialization vector */
73 static DES_cblock pvec; /* padding vector */
75 static char bits[] = { /* used to extract bits from a char */
76 '\200', '\100', '\040', '\020', '\010', '\004', '\002', '\001'
79 static int pflag; /* 1 to preserve parity bits */
81 static DES_key_schedule schedule; /* expanded DES key */
83 static unsigned char des_buf[8];/* shared buffer for get_des_char/put_des_char */
84 static int des_ct = 0; /* count for get_des_char/put_des_char */
85 static int des_n = 0; /* index for put_des_char/get_des_char */
88 /* init_des_cipher: initialize DES */
97 /* initialize the initialization vector */
100 /* initialize the padding vector */
101 for (i = 0; i < 8; i++)
102 pvec[i] = (char) (arc4random() % 256);
107 /* get_des_char: return next char in an encrypted file */
109 get_des_char(FILE *fp)
112 if (des_n >= des_ct) {
114 des_ct = cbc_decode(des_buf, fp);
116 return (des_ct > 0) ? des_buf[des_n++] : EOF;
123 /* put_des_char: write a char to an encrypted file; return char written */
125 put_des_char(int c, FILE *fp)
128 if (des_n == sizeof des_buf) {
129 des_ct = cbc_encode(des_buf, des_n, fp);
132 return (des_ct >= 0) ? (des_buf[des_n++] = c) : EOF;
134 return (fputc(c, fp));
139 /* flush_des_file: flush an encrypted file's output; return status */
141 flush_des_file(FILE *fp)
144 if (des_n == sizeof des_buf) {
145 des_ct = cbc_encode(des_buf, des_n, fp);
148 return (des_ct >= 0 && cbc_encode(des_buf, des_n, fp) >= 0) ? 0 : EOF;
156 * get keyword from tty or stdin
161 char *p; /* used to obtain the key */
162 DES_cblock msgbuf; /* I/O buffer */
167 if (*(p = getpass("Enter key: "))) {
170 * copy it, nul-padded, into the key area
172 expand_des_key(msgbuf, p);
173 MEMZERO(p, _PASSWORD_LEN);
174 set_des_key(&msgbuf);
175 MEMZERO(msgbuf, sizeof msgbuf);
183 * print a warning message and, possibly, terminate
186 des_error(const char *s)
188 errmsg = s ? s : strerror(errno);
192 * map a hex character to an integer
195 hex_to_binary(int c, int radix)
198 case '0': return(0x0);
199 case '1': return(0x1);
200 case '2': return(radix > 2 ? 0x2 : -1);
201 case '3': return(radix > 3 ? 0x3 : -1);
202 case '4': return(radix > 4 ? 0x4 : -1);
203 case '5': return(radix > 5 ? 0x5 : -1);
204 case '6': return(radix > 6 ? 0x6 : -1);
205 case '7': return(radix > 7 ? 0x7 : -1);
206 case '8': return(radix > 8 ? 0x8 : -1);
207 case '9': return(radix > 9 ? 0x9 : -1);
208 case 'A': case 'a': return(radix > 10 ? 0xa : -1);
209 case 'B': case 'b': return(radix > 11 ? 0xb : -1);
210 case 'C': case 'c': return(radix > 12 ? 0xc : -1);
211 case 'D': case 'd': return(radix > 13 ? 0xd : -1);
212 case 'E': case 'e': return(radix > 14 ? 0xe : -1);
213 case 'F': case 'f': return(radix > 15 ? 0xf : -1);
222 * convert the key to a bit pattern
224 * kbuf the key itself
227 expand_des_key(char *obuf, char *kbuf)
229 int i, j; /* counter in a for loop */
230 int nbuf[64]; /* used for hex/key translation */
233 * leading '0x' or '0X' == hex key
235 if (kbuf[0] == '0' && (kbuf[1] == 'x' || kbuf[1] == 'X')) {
238 * now translate it, bombing on any illegal hex digit
240 for (i = 0; i < 16 && kbuf[i]; i++)
241 if ((nbuf[i] = hex_to_binary((int) kbuf[i], 16)) == -1)
242 des_error("bad hex digit in key");
245 for (i = 0; i < 8; i++)
247 ((nbuf[2*i]&0xf)<<4) | (nbuf[2*i+1]&0xf);
248 /* preserve parity bits */
253 * leading '0b' or '0B' == binary key
255 if (kbuf[0] == '0' && (kbuf[1] == 'b' || kbuf[1] == 'B')) {
258 * now translate it, bombing on any illegal binary digit
260 for (i = 0; kbuf[i] && i < 16; i++)
261 if ((nbuf[i] = hex_to_binary((int) kbuf[i], 2)) == -1)
262 des_error("bad binary digit in key");
265 for (i = 0; i < 8; i++)
266 for (j = 0; j < 8; j++)
267 obuf[i] = (obuf[i]<<1)|nbuf[8*i+j];
268 /* preserve parity bits */
273 * no special leader -- ASCII
275 (void)strncpy(obuf, kbuf, 8);
282 * This sets the DES key and (if you're using the deszip version)
283 * the direction of the transformation. This uses the Sun
284 * to map the 64-bit key onto the 56 bits that the key schedule
285 * generation routines use: the old way, which just uses the user-
286 * supplied 64 bits as is, and the new way, which resets the parity
287 * bit to be the same as the low-order bit in each character. The
288 * new way generates a greater variety of key schedules, since many
289 * systems set the parity (high) bit of each character to 0, and the
290 * DES ignores the low order bit of each character.
293 set_des_key(DES_cblock *buf) /* key block */
295 int i, j; /* counter in a for loop */
296 int par; /* parity counter */
299 * if the parity is not preserved, flip it
302 for (i = 0; i < 8; i++) {
304 for (j = 1; j < 8; j++)
305 if ((bits[j] & (*buf)[i]) != 0)
307 if ((par & 0x01) == 0x01)
310 (*buf)[i] = ((*buf)[i] & 0x7f) | 0x80;
314 DES_set_odd_parity(buf);
315 DES_set_key(buf, &schedule);
320 * This encrypts using the Cipher Block Chaining mode of DES
323 cbc_encode(unsigned char *msgbuf, int n, FILE *fp)
325 int inverse = 0; /* 0 to encrypt, 1 to decrypt */
328 * do the transformation
331 for (n = 0; n < 8; n++)
332 msgbuf[n] ^= ivec[n];
333 DES_XFORM((DES_cblock *)msgbuf);
334 MEMCPY(ivec, msgbuf, 8);
335 return WRITE(msgbuf, 8, fp);
338 * at EOF or last block -- in either case, the last byte contains
339 * the character representation of the number of bytes in it
342 MEMZERO(msgbuf + n, 8 - n);
345 * Pad the last block randomly
347 (void)MEMCPY(msgbuf + n, pvec, 8 - n);
349 for (n = 0; n < 8; n++)
350 msgbuf[n] ^= ivec[n];
351 DES_XFORM((DES_cblock *)msgbuf);
352 return WRITE(msgbuf, 8, fp);
356 * This decrypts using the Cipher Block Chaining mode of DES
358 * fp input file descriptor
361 cbc_decode(unsigned char *msgbuf, FILE *fp)
363 DES_cblock tbuf; /* temp buffer for initialization vector */
364 int n; /* number of bytes actually read */
365 int c; /* used to test for EOF */
366 int inverse = 1; /* 0 to encrypt, 1 to decrypt */
368 if ((n = READ(msgbuf, 8, fp)) == 8) {
370 * do the transformation
372 MEMCPY(tbuf, msgbuf, 8);
373 DES_XFORM((DES_cblock *)msgbuf);
374 for (c = 0; c < 8; c++)
375 msgbuf[c] ^= ivec[c];
376 MEMCPY(ivec, tbuf, 8);
378 * if the last one, handle it specially
380 if ((c = fgetc(fp)) == EOF) {
382 if (n < 0 || n > 7) {
383 des_error("decryption failed (block corrupted)");
391 des_error("decryption failed (incomplete block)");
393 des_error("cannot read file");