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 * 3. 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
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * from: @(#)bdes.c 5.5 (Berkeley) 6/27/91
35 * @(#)cbc.c,v 1.2 1994/02/01 00:34:36 alm Exp
36 * $FreeBSD: head/bin/ed/cbc.c 300340 2016-05-21 00:45:42Z pfg $
39 #include <sys/types.h>
44 #include <openssl/des.h>
45 #define ED_DES_INCLUDES
52 * BSD and System V systems offer special library calls that do
53 * block move_liness and fills, so if possible we take advantage of them
55 #define MEMCPY(dest,src,len) memcpy((dest),(src),(len))
56 #define MEMZERO(dest,len) memset((dest), 0, (len))
58 /* Hide the calls to the primitive encryption routines. */
59 #define DES_XFORM(buf) \
60 DES_ecb_encrypt(buf, buf, &schedule, \
61 inverse ? DES_DECRYPT : DES_ENCRYPT);
64 * read/write - no error checking
66 #define READ(buf, n, fp) fread(buf, sizeof(char), n, fp)
67 #define WRITE(buf, n, fp) fwrite(buf, sizeof(char), n, fp)
70 * global variables and related macros
74 static DES_cblock ivec
; /* initialization vector */
75 static DES_cblock pvec
; /* padding vector */
77 static char bits
[] = { /* used to extract bits from a char */
78 '\200', '\100', '\040', '\020', '\010', '\004', '\002', '\001'
81 static int pflag
; /* 1 to preserve parity bits */
83 static DES_key_schedule schedule
; /* expanded DES key */
85 static unsigned char des_buf
[8];/* shared buffer for get_des_char/put_des_char */
86 static int des_ct
= 0; /* count for get_des_char/put_des_char */
87 static int des_n
= 0; /* index for put_des_char/get_des_char */
90 /* init_des_cipher: initialize DES */
97 /* initialize the initialization vector */
100 /* initialize the padding vector */
101 arc4random_buf(pvec
, sizeof(pvec
));
106 /* get_des_char: return next char in an encrypted file */
108 get_des_char(FILE *fp
)
111 if (des_n
>= des_ct
) {
113 des_ct
= cbc_decode(des_buf
, fp
);
115 return (des_ct
> 0) ? des_buf
[des_n
++] : EOF
;
122 /* put_des_char: write a char to an encrypted file; return char written */
124 put_des_char(int c
, FILE *fp
)
127 if (des_n
== sizeof des_buf
) {
128 des_ct
= cbc_encode(des_buf
, des_n
, fp
);
131 return (des_ct
>= 0) ? (des_buf
[des_n
++] = c
) : EOF
;
133 return (fputc(c
, fp
));
138 /* flush_des_file: flush an encrypted file's output; return status */
140 flush_des_file(FILE *fp
)
143 if (des_n
== sizeof des_buf
) {
144 des_ct
= cbc_encode(des_buf
, des_n
, fp
);
147 return (des_ct
>= 0 && cbc_encode(des_buf
, des_n
, fp
) >= 0) ? 0 : EOF
;
155 * get keyword from tty or stdin
160 char *p
; /* used to obtain the key */
161 DES_cblock msgbuf
; /* I/O buffer */
166 if ((p
= getpass("Enter key: ")) != NULL
&& *p
!= '\0') {
169 * copy it, nul-padded, into the key area
171 expand_des_key(msgbuf
, p
);
172 MEMZERO(p
, _PASSWORD_LEN
);
173 set_des_key(&msgbuf
);
174 MEMZERO(msgbuf
, sizeof msgbuf
);
182 * print a warning message and, possibly, terminate
185 des_error(const char *s
)
187 errmsg
= s
? s
: strerror(errno
);
191 * map a hex character to an integer
194 hex_to_binary(int c
, int radix
)
197 case '0': return(0x0);
198 case '1': return(0x1);
199 case '2': return(radix
> 2 ? 0x2 : -1);
200 case '3': return(radix
> 3 ? 0x3 : -1);
201 case '4': return(radix
> 4 ? 0x4 : -1);
202 case '5': return(radix
> 5 ? 0x5 : -1);
203 case '6': return(radix
> 6 ? 0x6 : -1);
204 case '7': return(radix
> 7 ? 0x7 : -1);
205 case '8': return(radix
> 8 ? 0x8 : -1);
206 case '9': return(radix
> 9 ? 0x9 : -1);
207 case 'A': case 'a': return(radix
> 10 ? 0xa : -1);
208 case 'B': case 'b': return(radix
> 11 ? 0xb : -1);
209 case 'C': case 'c': return(radix
> 12 ? 0xc : -1);
210 case 'D': case 'd': return(radix
> 13 ? 0xd : -1);
211 case 'E': case 'e': return(radix
> 14 ? 0xe : -1);
212 case 'F': case 'f': return(radix
> 15 ? 0xf : -1);
221 * convert the key to a bit pattern
223 * kbuf the key itself
226 expand_des_key(char *obuf
, char *kbuf
)
228 int i
, j
; /* counter in a for loop */
229 int nbuf
[64]; /* used for hex/key translation */
232 * leading '0x' or '0X' == hex key
234 if (kbuf
[0] == '0' && (kbuf
[1] == 'x' || kbuf
[1] == 'X')) {
237 * now translate it, bombing on any illegal hex digit
239 for (i
= 0; i
< 16 && kbuf
[i
]; i
++)
240 if ((nbuf
[i
] = hex_to_binary((int) kbuf
[i
], 16)) == -1)
241 des_error("bad hex digit in key");
244 for (i
= 0; i
< 8; i
++)
246 ((nbuf
[2*i
]&0xf)<<4) | (nbuf
[2*i
+1]&0xf);
247 /* preserve parity bits */
252 * leading '0b' or '0B' == binary key
254 if (kbuf
[0] == '0' && (kbuf
[1] == 'b' || kbuf
[1] == 'B')) {
257 * now translate it, bombing on any illegal binary digit
259 for (i
= 0; i
< 16 && kbuf
[i
]; i
++)
260 if ((nbuf
[i
] = hex_to_binary((int) kbuf
[i
], 2)) == -1)
261 des_error("bad binary digit in key");
264 for (i
= 0; i
< 8; i
++)
265 for (j
= 0; j
< 8; j
++)
266 obuf
[i
] = (obuf
[i
]<<1)|nbuf
[8*i
+j
];
267 /* preserve parity bits */
272 * no special leader -- ASCII
274 strncpy(obuf
, kbuf
, 8);
281 * This sets the DES key and (if you're using the deszip version)
282 * the direction of the transformation. This uses the Sun
283 * to map the 64-bit key onto the 56 bits that the key schedule
284 * generation routines use: the old way, which just uses the user-
285 * supplied 64 bits as is, and the new way, which resets the parity
286 * bit to be the same as the low-order bit in each character. The
287 * new way generates a greater variety of key schedules, since many
288 * systems set the parity (high) bit of each character to 0, and the
289 * DES ignores the low order bit of each character.
292 set_des_key(DES_cblock
*buf
) /* key block */
294 int i
, j
; /* counter in a for loop */
295 int par
; /* parity counter */
298 * if the parity is not preserved, flip it
301 for (i
= 0; i
< 8; i
++) {
303 for (j
= 1; j
< 8; j
++)
304 if ((bits
[j
] & (*buf
)[i
]) != 0)
306 if ((par
& 0x01) == 0x01)
309 (*buf
)[i
] = ((*buf
)[i
] & 0x7f) | 0x80;
313 DES_set_odd_parity(buf
);
314 DES_set_key(buf
, &schedule
);
319 * This encrypts using the Cipher Block Chaining mode of DES
322 cbc_encode(unsigned char *msgbuf
, int n
, FILE *fp
)
324 int inverse
= 0; /* 0 to encrypt, 1 to decrypt */
327 * do the transformation
330 for (n
= 0; n
< 8; n
++)
331 msgbuf
[n
] ^= ivec
[n
];
332 DES_XFORM((DES_cblock
*)msgbuf
);
333 MEMCPY(ivec
, msgbuf
, 8);
334 return WRITE(msgbuf
, 8, fp
);
337 * at EOF or last block -- in either case, the last byte contains
338 * the character representation of the number of bytes in it
341 MEMZERO(msgbuf + n, 8 - n);
344 * Pad the last block randomly
346 MEMCPY(msgbuf
+ n
, pvec
, 8 - n
);
348 for (n
= 0; n
< 8; n
++)
349 msgbuf
[n
] ^= ivec
[n
];
350 DES_XFORM((DES_cblock
*)msgbuf
);
351 return WRITE(msgbuf
, 8, fp
);
355 * This decrypts using the Cipher Block Chaining mode of DES
357 * fp input file descriptor
360 cbc_decode(unsigned char *msgbuf
, FILE *fp
)
362 DES_cblock tbuf
; /* temp buffer for initialization vector */
363 int n
; /* number of bytes actually read */
364 int c
; /* used to test for EOF */
365 int inverse
= 1; /* 0 to encrypt, 1 to decrypt */
367 if ((n
= READ(msgbuf
, 8, fp
)) == 8) {
369 * do the transformation
371 MEMCPY(tbuf
, msgbuf
, 8);
372 DES_XFORM((DES_cblock
*)msgbuf
);
373 for (c
= 0; c
< 8; c
++)
374 msgbuf
[c
] ^= ivec
[c
];
375 MEMCPY(ivec
, tbuf
, 8);
377 * if the last one, handle it specially
379 if ((c
= fgetc(fp
)) == EOF
) {
381 if (n
< 0 || n
> 7) {
382 des_error("decryption failed (block corrupted)");
390 des_error("decryption failed (incomplete block)");
392 des_error("cannot read file");