xref: /netbsd-src/lib/libcrypt/crypt.c (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1 /*	$NetBSD: crypt.c,v 1.16 2000/07/06 11:13:49 ad Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Tom Truscott.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #if !defined(lint)
41 #if 0
42 static char sccsid[] = "@(#)crypt.c	8.1.1.1 (Berkeley) 8/18/93";
43 #else
44 __RCSID("$NetBSD: crypt.c,v 1.16 2000/07/06 11:13:49 ad Exp $");
45 #endif
46 #endif /* not lint */
47 
48 #include <limits.h>
49 #include <pwd.h>
50 #include <stdlib.h>
51 #include <unistd.h>
52 
53 /*
54  * UNIX password, and DES, encryption.
55  * By Tom Truscott, trt@rti.rti.org,
56  * from algorithms by Robert W. Baldwin and James Gillogly.
57  *
58  * References:
59  * "Mathematical Cryptology for Computer Scientists and Mathematicians,"
60  * by Wayne Patterson, 1987, ISBN 0-8476-7438-X.
61  *
62  * "Password Security: A Case History," R. Morris and Ken Thompson,
63  * Communications of the ACM, vol. 22, pp. 594-597, Nov. 1979.
64  *
65  * "DES will be Totally Insecure within Ten Years," M.E. Hellman,
66  * IEEE Spectrum, vol. 16, pp. 32-39, July 1979.
67  */
68 
69 /* =====  Configuration ==================== */
70 
71 /*
72  * define "MUST_ALIGN" if your compiler cannot load/store
73  * long integers at arbitrary (e.g. odd) memory locations.
74  * (Either that or never pass unaligned addresses to des_cipher!)
75  */
76 #if !defined(__vax__) && !defined(__i386__)
77 #define	MUST_ALIGN
78 #endif
79 
80 #ifdef CHAR_BITS
81 #if CHAR_BITS != 8
82 	#error C_block structure assumes 8 bit characters
83 #endif
84 #endif
85 
86 /*
87  * define "B64" to be the declaration for a 64 bit integer.
88  * XXX this feature is currently unused, see "endian" comment below.
89  */
90 #if defined(cray)
91 #define	B64	long
92 #endif
93 #if defined(convex)
94 #define	B64	long long
95 #endif
96 
97 /*
98  * define "LARGEDATA" to get faster permutations, by using about 72 kilobytes
99  * of lookup tables.  This speeds up des_setkey() and des_cipher(), but has
100  * little effect on crypt().
101  */
102 #if defined(notdef)
103 #define	LARGEDATA
104 #endif
105 
106 /* compile with "-DSTATIC=void" when profiling */
107 #ifndef STATIC
108 #define	STATIC	static void
109 #endif
110 
111 /* ==================================== */
112 
113 /*
114  * Cipher-block representation (Bob Baldwin):
115  *
116  * DES operates on groups of 64 bits, numbered 1..64 (sigh).  One
117  * representation is to store one bit per byte in an array of bytes.  Bit N of
118  * the NBS spec is stored as the LSB of the Nth byte (index N-1) in the array.
119  * Another representation stores the 64 bits in 8 bytes, with bits 1..8 in the
120  * first byte, 9..16 in the second, and so on.  The DES spec apparently has
121  * bit 1 in the MSB of the first byte, but that is particularly noxious so we
122  * bit-reverse each byte so that bit 1 is the LSB of the first byte, bit 8 is
123  * the MSB of the first byte.  Specifically, the 64-bit input data and key are
124  * converted to LSB format, and the output 64-bit block is converted back into
125  * MSB format.
126  *
127  * DES operates internally on groups of 32 bits which are expanded to 48 bits
128  * by permutation E and shrunk back to 32 bits by the S boxes.  To speed up
129  * the computation, the expansion is applied only once, the expanded
130  * representation is maintained during the encryption, and a compression
131  * permutation is applied only at the end.  To speed up the S-box lookups,
132  * the 48 bits are maintained as eight 6 bit groups, one per byte, which
133  * directly feed the eight S-boxes.  Within each byte, the 6 bits are the
134  * most significant ones.  The low two bits of each byte are zero.  (Thus,
135  * bit 1 of the 48 bit E expansion is stored as the "4"-valued bit of the
136  * first byte in the eight byte representation, bit 2 of the 48 bit value is
137  * the "8"-valued bit, and so on.)  In fact, a combined "SPE"-box lookup is
138  * used, in which the output is the 64 bit result of an S-box lookup which
139  * has been permuted by P and expanded by E, and is ready for use in the next
140  * iteration.  Two 32-bit wide tables, SPE[0] and SPE[1], are used for this
141  * lookup.  Since each byte in the 48 bit path is a multiple of four, indexed
142  * lookup of SPE[0] and SPE[1] is simple and fast.  The key schedule and
143  * "salt" are also converted to this 8*(6+2) format.  The SPE table size is
144  * 8*64*8 = 4K bytes.
145  *
146  * To speed up bit-parallel operations (such as XOR), the 8 byte
147  * representation is "union"ed with 32 bit values "i0" and "i1", and, on
148  * machines which support it, a 64 bit value "b64".  This data structure,
149  * "C_block", has two problems.  First, alignment restrictions must be
150  * honored.  Second, the byte-order (e.g. little-endian or big-endian) of
151  * the architecture becomes visible.
152  *
153  * The byte-order problem is unfortunate, since on the one hand it is good
154  * to have a machine-independent C_block representation (bits 1..8 in the
155  * first byte, etc.), and on the other hand it is good for the LSB of the
156  * first byte to be the LSB of i0.  We cannot have both these things, so we
157  * currently use the "little-endian" representation and avoid any multi-byte
158  * operations that depend on byte order.  This largely precludes use of the
159  * 64-bit datatype since the relative order of i0 and i1 are unknown.  It
160  * also inhibits grouping the SPE table to look up 12 bits at a time.  (The
161  * 12 bits can be stored in a 16-bit field with 3 low-order zeroes and 1
162  * high-order zero, providing fast indexing into a 64-bit wide SPE.)  On the
163  * other hand, 64-bit datatypes are currently rare, and a 12-bit SPE lookup
164  * requires a 128 kilobyte table, so perhaps this is not a big loss.
165  *
166  * Permutation representation (Jim Gillogly):
167  *
168  * A transformation is defined by its effect on each of the 8 bytes of the
169  * 64-bit input.  For each byte we give a 64-bit output that has the bits in
170  * the input distributed appropriately.  The transformation is then the OR
171  * of the 8 sets of 64-bits.  This uses 8*256*8 = 16K bytes of storage for
172  * each transformation.  Unless LARGEDATA is defined, however, a more compact
173  * table is used which looks up 16 4-bit "chunks" rather than 8 8-bit chunks.
174  * The smaller table uses 16*16*8 = 2K bytes for each transformation.  This
175  * is slower but tolerable, particularly for password encryption in which
176  * the SPE transformation is iterated many times.  The small tables total 9K
177  * bytes, the large tables total 72K bytes.
178  *
179  * The transformations used are:
180  * IE3264: MSB->LSB conversion, initial permutation, and expansion.
181  *	This is done by collecting the 32 even-numbered bits and applying
182  *	a 32->64 bit transformation, and then collecting the 32 odd-numbered
183  *	bits and applying the same transformation.  Since there are only
184  *	32 input bits, the IE3264 transformation table is half the size of
185  *	the usual table.
186  * CF6464: Compression, final permutation, and LSB->MSB conversion.
187  *	This is done by two trivial 48->32 bit compressions to obtain
188  *	a 64-bit block (the bit numbering is given in the "CIFP" table)
189  *	followed by a 64->64 bit "cleanup" transformation.  (It would
190  *	be possible to group the bits in the 64-bit block so that 2
191  *	identical 32->32 bit transformations could be used instead,
192  *	saving a factor of 4 in space and possibly 2 in time, but
193  *	byte-ordering and other complications rear their ugly head.
194  *	Similar opportunities/problems arise in the key schedule
195  *	transforms.)
196  * PC1ROT: MSB->LSB, PC1 permutation, rotate, and PC2 permutation.
197  *	This admittedly baroque 64->64 bit transformation is used to
198  *	produce the first code (in 8*(6+2) format) of the key schedule.
199  * PC2ROT[0]: Inverse PC2 permutation, rotate, and PC2 permutation.
200  *	It would be possible to define 15 more transformations, each
201  *	with a different rotation, to generate the entire key schedule.
202  *	To save space, however, we instead permute each code into the
203  *	next by using a transformation that "undoes" the PC2 permutation,
204  *	rotates the code, and then applies PC2.  Unfortunately, PC2
205  *	transforms 56 bits into 48 bits, dropping 8 bits, so PC2 is not
206  *	invertible.  We get around that problem by using a modified PC2
207  *	which retains the 8 otherwise-lost bits in the unused low-order
208  *	bits of each byte.  The low-order bits are cleared when the
209  *	codes are stored into the key schedule.
210  * PC2ROT[1]: Same as PC2ROT[0], but with two rotations.
211  *	This is faster than applying PC2ROT[0] twice,
212  *
213  * The Bell Labs "salt" (Bob Baldwin):
214  *
215  * The salting is a simple permutation applied to the 48-bit result of E.
216  * Specifically, if bit i (1 <= i <= 24) of the salt is set then bits i and
217  * i+24 of the result are swapped.  The salt is thus a 24 bit number, with
218  * 16777216 possible values.  (The original salt was 12 bits and could not
219  * swap bits 13..24 with 36..48.)
220  *
221  * It is possible, but ugly, to warp the SPE table to account for the salt
222  * permutation.  Fortunately, the conditional bit swapping requires only
223  * about four machine instructions and can be done on-the-fly with about an
224  * 8% performance penalty.
225  */
226 
227 typedef union {
228 	unsigned char b[8];
229 	struct {
230 		int32_t	i0;
231 		int32_t	i1;
232 	} b32;
233 #if defined(B64)
234 	B64	b64;
235 #endif
236 } C_block;
237 
238 /*
239  * Convert twenty-four-bit long in host-order
240  * to six bits (and 2 low-order zeroes) per char little-endian format.
241  */
242 #define	TO_SIX_BIT(rslt, src) {				\
243 		C_block cvt;				\
244 		cvt.b[0] = src; src >>= 6;		\
245 		cvt.b[1] = src; src >>= 6;		\
246 		cvt.b[2] = src; src >>= 6;		\
247 		cvt.b[3] = src;				\
248 		rslt = (cvt.b32.i0 & 0x3f3f3f3fL) << 2;	\
249 	}
250 
251 /*
252  * These macros may someday permit efficient use of 64-bit integers.
253  */
254 #define	ZERO(d,d0,d1)			d0 = 0, d1 = 0
255 #define	LOAD(d,d0,d1,bl)		d0 = (bl).b32.i0, d1 = (bl).b32.i1
256 #define	LOADREG(d,d0,d1,s,s0,s1)	d0 = s0, d1 = s1
257 #define	OR(d,d0,d1,bl)			d0 |= (bl).b32.i0, d1 |= (bl).b32.i1
258 #define	STORE(s,s0,s1,bl)		(bl).b32.i0 = s0, (bl).b32.i1 = s1
259 #define	DCL_BLOCK(d,d0,d1)		int32_t d0, d1
260 
261 #if defined(LARGEDATA)
262 	/* Waste memory like crazy.  Also, do permutations in line */
263 #define	LGCHUNKBITS	3
264 #define	CHUNKBITS	(1<<LGCHUNKBITS)
265 #define	PERM6464(d,d0,d1,cpp,p)				\
266 	LOAD(d,d0,d1,(p)[(0<<CHUNKBITS)+(cpp)[0]]);		\
267 	OR (d,d0,d1,(p)[(1<<CHUNKBITS)+(cpp)[1]]);		\
268 	OR (d,d0,d1,(p)[(2<<CHUNKBITS)+(cpp)[2]]);		\
269 	OR (d,d0,d1,(p)[(3<<CHUNKBITS)+(cpp)[3]]);		\
270 	OR (d,d0,d1,(p)[(4<<CHUNKBITS)+(cpp)[4]]);		\
271 	OR (d,d0,d1,(p)[(5<<CHUNKBITS)+(cpp)[5]]);		\
272 	OR (d,d0,d1,(p)[(6<<CHUNKBITS)+(cpp)[6]]);		\
273 	OR (d,d0,d1,(p)[(7<<CHUNKBITS)+(cpp)[7]]);
274 #define	PERM3264(d,d0,d1,cpp,p)				\
275 	LOAD(d,d0,d1,(p)[(0<<CHUNKBITS)+(cpp)[0]]);		\
276 	OR (d,d0,d1,(p)[(1<<CHUNKBITS)+(cpp)[1]]);		\
277 	OR (d,d0,d1,(p)[(2<<CHUNKBITS)+(cpp)[2]]);		\
278 	OR (d,d0,d1,(p)[(3<<CHUNKBITS)+(cpp)[3]]);
279 #else
280 	/* "small data" */
281 #define	LGCHUNKBITS	2
282 #define	CHUNKBITS	(1<<LGCHUNKBITS)
283 #define	PERM6464(d,d0,d1,cpp,p)				\
284 	{ C_block tblk; permute(cpp,&tblk,p,8); LOAD (d,d0,d1,tblk); }
285 #define	PERM3264(d,d0,d1,cpp,p)				\
286 	{ C_block tblk; permute(cpp,&tblk,p,4); LOAD (d,d0,d1,tblk); }
287 #endif /* LARGEDATA */
288 
289 STATIC	init_des __P((void));
290 STATIC	init_perm __P((C_block [64/CHUNKBITS][1<<CHUNKBITS], unsigned char [64], int, int));
291 #ifndef LARGEDATA
292 STATIC	permute __P((unsigned char *, C_block *, C_block *, int));
293 #endif
294 #ifdef DEBUG
295 STATIC	prtab __P((char *, unsigned char *, int));
296 #endif
297 
298 
299 #ifndef LARGEDATA
300 STATIC
301 permute(cp, out, p, chars_in)
302 	unsigned char *cp;
303 	C_block *out;
304 	C_block *p;
305 	int chars_in;
306 {
307 	DCL_BLOCK(D,D0,D1);
308 	C_block *tp;
309 	int t;
310 
311 	ZERO(D,D0,D1);
312 	do {
313 		t = *cp++;
314 		tp = &p[t&0xf]; OR(D,D0,D1,*tp); p += (1<<CHUNKBITS);
315 		tp = &p[t>>4];  OR(D,D0,D1,*tp); p += (1<<CHUNKBITS);
316 	} while (--chars_in > 0);
317 	STORE(D,D0,D1,*out);
318 }
319 #endif /* LARGEDATA */
320 
321 
322 /* =====  (mostly) Standard DES Tables ==================== */
323 
324 static unsigned char IP[] = {		/* initial permutation */
325 	58, 50, 42, 34, 26, 18, 10,  2,
326 	60, 52, 44, 36, 28, 20, 12,  4,
327 	62, 54, 46, 38, 30, 22, 14,  6,
328 	64, 56, 48, 40, 32, 24, 16,  8,
329 	57, 49, 41, 33, 25, 17,  9,  1,
330 	59, 51, 43, 35, 27, 19, 11,  3,
331 	61, 53, 45, 37, 29, 21, 13,  5,
332 	63, 55, 47, 39, 31, 23, 15,  7,
333 };
334 
335 /* The final permutation is the inverse of IP - no table is necessary */
336 
337 static unsigned char ExpandTr[] = {	/* expansion operation */
338 	32,  1,  2,  3,  4,  5,
339 	 4,  5,  6,  7,  8,  9,
340 	 8,  9, 10, 11, 12, 13,
341 	12, 13, 14, 15, 16, 17,
342 	16, 17, 18, 19, 20, 21,
343 	20, 21, 22, 23, 24, 25,
344 	24, 25, 26, 27, 28, 29,
345 	28, 29, 30, 31, 32,  1,
346 };
347 
348 static unsigned char PC1[] = {		/* permuted choice table 1 */
349 	57, 49, 41, 33, 25, 17,  9,
350 	 1, 58, 50, 42, 34, 26, 18,
351 	10,  2, 59, 51, 43, 35, 27,
352 	19, 11,  3, 60, 52, 44, 36,
353 
354 	63, 55, 47, 39, 31, 23, 15,
355 	 7, 62, 54, 46, 38, 30, 22,
356 	14,  6, 61, 53, 45, 37, 29,
357 	21, 13,  5, 28, 20, 12,  4,
358 };
359 
360 static unsigned char Rotates[] = {	/* PC1 rotation schedule */
361 	1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1,
362 };
363 
364 /* note: each "row" of PC2 is left-padded with bits that make it invertible */
365 static unsigned char PC2[] = {		/* permuted choice table 2 */
366 	 9, 18,    14, 17, 11, 24,  1,  5,
367 	22, 25,     3, 28, 15,  6, 21, 10,
368 	35, 38,    23, 19, 12,  4, 26,  8,
369 	43, 54,    16,  7, 27, 20, 13,  2,
370 
371 	 0,  0,    41, 52, 31, 37, 47, 55,
372 	 0,  0,    30, 40, 51, 45, 33, 48,
373 	 0,  0,    44, 49, 39, 56, 34, 53,
374 	 0,  0,    46, 42, 50, 36, 29, 32,
375 };
376 
377 static unsigned char S[8][64] = {	/* 48->32 bit substitution tables */
378 					/* S[1]			*/
379 	{ 14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7,
380 	   0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8,
381 	   4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0,
382 	  15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13 },
383 					/* S[2]			*/
384 	{ 15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10,
385 	   3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5,
386 	   0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15,
387 	  13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9 },
388 					/* S[3]			*/
389 	{ 10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8,
390 	  13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1,
391 	  13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7,
392 	   1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12 },
393 					/* S[4]			*/
394 	{  7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15,
395 	  13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9,
396 	  10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4,
397 	   3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14 },
398 					/* S[5]			*/
399 	{  2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9,
400 	  14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6,
401 	   4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14,
402 	  11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3 },
403 					/* S[6]			*/
404 	{ 12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11,
405 	  10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8,
406 	   9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6,
407 	   4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13 },
408 					/* S[7]			*/
409 	{  4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1,
410 	  13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6,
411 	   1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2,
412 	   6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12 },
413 					/* S[8]			*/
414 	{ 13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7,
415 	   1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2,
416 	   7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8,
417 	   2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11 }
418 };
419 
420 static unsigned char P32Tr[] = {	/* 32-bit permutation function */
421 	16,  7, 20, 21,
422 	29, 12, 28, 17,
423 	 1, 15, 23, 26,
424 	 5, 18, 31, 10,
425 	 2,  8, 24, 14,
426 	32, 27,  3,  9,
427 	19, 13, 30,  6,
428 	22, 11,  4, 25,
429 };
430 
431 static unsigned char CIFP[] = {		/* compressed/interleaved permutation */
432 	 1,  2,  3,  4,   17, 18, 19, 20,
433 	 5,  6,  7,  8,   21, 22, 23, 24,
434 	 9, 10, 11, 12,   25, 26, 27, 28,
435 	13, 14, 15, 16,   29, 30, 31, 32,
436 
437 	33, 34, 35, 36,   49, 50, 51, 52,
438 	37, 38, 39, 40,   53, 54, 55, 56,
439 	41, 42, 43, 44,   57, 58, 59, 60,
440 	45, 46, 47, 48,   61, 62, 63, 64,
441 };
442 
443 static unsigned char itoa64[] =		/* 0..63 => ascii-64 */
444 	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
445 
446 
447 /* =====  Tables that are initialized at run time  ==================== */
448 
449 
450 static unsigned char a64toi[128];	/* ascii-64 => 0..63 */
451 
452 /* Initial key schedule permutation */
453 static C_block	PC1ROT[64/CHUNKBITS][1<<CHUNKBITS];
454 
455 /* Subsequent key schedule rotation permutations */
456 static C_block	PC2ROT[2][64/CHUNKBITS][1<<CHUNKBITS];
457 
458 /* Initial permutation/expansion table */
459 static C_block	IE3264[32/CHUNKBITS][1<<CHUNKBITS];
460 
461 /* Table that combines the S, P, and E operations.  */
462 static int32_t SPE[2][8][64];
463 
464 /* compressed/interleaved => final permutation table */
465 static C_block	CF6464[64/CHUNKBITS][1<<CHUNKBITS];
466 
467 
468 /* ==================================== */
469 
470 
471 static C_block	constdatablock;			/* encryption constant */
472 static char	cryptresult[1+4+4+11+1];	/* encrypted result */
473 
474 /*
475  * Return a pointer to static data consisting of the "setting"
476  * followed by an encryption produced by the "key" and "setting".
477  */
478 char *
479 crypt(key, setting)
480 	const char *key;
481 	const char *setting;
482 {
483 	extern char *__md5crypt(const char *, const char *);	/* XXX */
484 	char *encp;
485 	int32_t i;
486 	int t;
487 	int32_t salt;
488 	int num_iter, salt_size;
489 	C_block keyblock, rsltblock;
490 
491 	/* Non-DES encryption schemes hook in here. */
492 	if (setting[0] == _PASSWORD_NONDES) {
493 		switch (setting[1]) {
494 #ifdef notyet
495 		case '2':
496 			return (__bcrypt(key, setting));
497 #endif
498 		case '1':
499 		default:
500 			return (__md5crypt(key, setting));
501 		}
502 	}
503 
504 	for (i = 0; i < 8; i++) {
505 		if ((t = 2*(unsigned char)(*key)) != 0)
506 			key++;
507 		keyblock.b[i] = t;
508 	}
509 	if (des_setkey((char *)keyblock.b))	/* also initializes "a64toi" */
510 		return (NULL);
511 
512 	encp = &cryptresult[0];
513 	switch (*setting) {
514 	case _PASSWORD_EFMT1:
515 		/*
516 		 * Involve the rest of the password 8 characters at a time.
517 		 */
518 		while (*key) {
519 			if (des_cipher((char *)&keyblock,
520 			    (char *)&keyblock, 0L, 1))
521 				return (NULL);
522 			for (i = 0; i < 8; i++) {
523 				if ((t = 2*(unsigned char)(*key)) != 0)
524 					key++;
525 				keyblock.b[i] ^= t;
526 			}
527 			if (des_setkey((char *)keyblock.b))
528 				return (NULL);
529 		}
530 
531 		*encp++ = *setting++;
532 
533 		/* get iteration count */
534 		num_iter = 0;
535 		for (i = 4; --i >= 0; ) {
536 			if ((t = (unsigned char)setting[i]) == '\0')
537 				t = '.';
538 			encp[i] = t;
539 			num_iter = (num_iter<<6) | a64toi[t];
540 		}
541 		setting += 4;
542 		encp += 4;
543 		salt_size = 4;
544 		break;
545 	default:
546 		num_iter = 25;
547 		salt_size = 2;
548 	}
549 
550 	salt = 0;
551 	for (i = salt_size; --i >= 0; ) {
552 		if ((t = (unsigned char)setting[i]) == '\0')
553 			t = '.';
554 		encp[i] = t;
555 		salt = (salt<<6) | a64toi[t];
556 	}
557 	encp += salt_size;
558 	if (des_cipher((char *)&constdatablock, (char *)&rsltblock,
559 	    salt, num_iter))
560 		return (NULL);
561 
562 	/*
563 	 * Encode the 64 cipher bits as 11 ascii characters.
564 	 */
565 	i = ((int32_t)((rsltblock.b[0]<<8) | rsltblock.b[1])<<8) |
566 	    rsltblock.b[2];
567 	encp[3] = itoa64[i&0x3f];	i >>= 6;
568 	encp[2] = itoa64[i&0x3f];	i >>= 6;
569 	encp[1] = itoa64[i&0x3f];	i >>= 6;
570 	encp[0] = itoa64[i];		encp += 4;
571 	i = ((int32_t)((rsltblock.b[3]<<8) | rsltblock.b[4])<<8) |
572 	    rsltblock.b[5];
573 	encp[3] = itoa64[i&0x3f];	i >>= 6;
574 	encp[2] = itoa64[i&0x3f];	i >>= 6;
575 	encp[1] = itoa64[i&0x3f];	i >>= 6;
576 	encp[0] = itoa64[i];		encp += 4;
577 	i = ((int32_t)((rsltblock.b[6])<<8) | rsltblock.b[7])<<2;
578 	encp[2] = itoa64[i&0x3f];	i >>= 6;
579 	encp[1] = itoa64[i&0x3f];	i >>= 6;
580 	encp[0] = itoa64[i];
581 
582 	encp[3] = 0;
583 
584 	return (cryptresult);
585 }
586 
587 
588 /*
589  * The Key Schedule, filled in by des_setkey() or setkey().
590  */
591 #define	KS_SIZE	16
592 static C_block	KS[KS_SIZE];
593 
594 /*
595  * Set up the key schedule from the key.
596  */
597 int
598 des_setkey(key)
599 	const char *key;
600 {
601 	DCL_BLOCK(K, K0, K1);
602 	C_block *ptabp;
603 	int i;
604 	static int des_ready = 0;
605 
606 	if (!des_ready) {
607 		init_des();
608 		des_ready = 1;
609 	}
610 
611 	PERM6464(K,K0,K1,(unsigned char *)key,(C_block *)PC1ROT);
612 	key = (char *)&KS[0];
613 	STORE(K&~0x03030303L, K0&~0x03030303L, K1, *(C_block *)key);
614 	for (i = 1; i < 16; i++) {
615 		key += sizeof(C_block);
616 		STORE(K,K0,K1,*(C_block *)key);
617 		ptabp = (C_block *)PC2ROT[Rotates[i]-1];
618 		PERM6464(K,K0,K1,(unsigned char *)key,ptabp);
619 		STORE(K&~0x03030303L, K0&~0x03030303L, K1, *(C_block *)key);
620 	}
621 	return (0);
622 }
623 
624 /*
625  * Encrypt (or decrypt if num_iter < 0) the 8 chars at "in" with abs(num_iter)
626  * iterations of DES, using the given 24-bit salt and the pre-computed key
627  * schedule, and store the resulting 8 chars at "out" (in == out is permitted).
628  *
629  * NOTE: the performance of this routine is critically dependent on your
630  * compiler and machine architecture.
631  */
632 int
633 des_cipher(in, out, salt, num_iter)
634 	const char *in;
635 	char *out;
636 	long salt;
637 	int num_iter;
638 {
639 	/* variables that we want in registers, most important first */
640 #if defined(pdp11)
641 	int j;
642 #endif
643 	int32_t L0, L1, R0, R1, k;
644 	C_block *kp;
645 	int ks_inc, loop_count;
646 	C_block B;
647 
648 	L0 = salt;
649 	TO_SIX_BIT(salt, L0);	/* convert to 4*(6+2) format */
650 
651 #if defined(__vax__) || defined(pdp11)
652 	salt = ~salt;	/* "x &~ y" is faster than "x & y". */
653 #define	SALT (~salt)
654 #else
655 #define	SALT salt
656 #endif
657 
658 #if defined(MUST_ALIGN)
659 	B.b[0] = in[0]; B.b[1] = in[1]; B.b[2] = in[2]; B.b[3] = in[3];
660 	B.b[4] = in[4]; B.b[5] = in[5]; B.b[6] = in[6]; B.b[7] = in[7];
661 	LOAD(L,L0,L1,B);
662 #else
663 	LOAD(L,L0,L1,*(C_block *)in);
664 #endif
665 	LOADREG(R,R0,R1,L,L0,L1);
666 	L0 &= 0x55555555L;
667 	L1 &= 0x55555555L;
668 	L0 = (L0 << 1) | L1;	/* L0 is the even-numbered input bits */
669 	R0 &= 0xaaaaaaaaL;
670 	R1 = (R1 >> 1) & 0x55555555L;
671 	L1 = R0 | R1;		/* L1 is the odd-numbered input bits */
672 	STORE(L,L0,L1,B);
673 	PERM3264(L,L0,L1,B.b,  (C_block *)IE3264);	/* even bits */
674 	PERM3264(R,R0,R1,B.b+4,(C_block *)IE3264);	/* odd bits */
675 
676 	if (num_iter >= 0)
677 	{		/* encryption */
678 		kp = &KS[0];
679 		ks_inc  = sizeof(*kp);
680 	}
681 	else
682 	{		/* decryption */
683 		num_iter = -num_iter;
684 		kp = &KS[KS_SIZE-1];
685 		ks_inc  = -(long)sizeof(*kp);
686 	}
687 
688 	while (--num_iter >= 0) {
689 		loop_count = 8;
690 		do {
691 
692 #define	SPTAB(t, i) \
693 	    (*(int32_t *)((unsigned char *)t + i*(sizeof(int32_t)/4)))
694 #if defined(gould)
695 			/* use this if B.b[i] is evaluated just once ... */
696 #define	DOXOR(x,y,i)	x^=SPTAB(SPE[0][i],B.b[i]); y^=SPTAB(SPE[1][i],B.b[i]);
697 #else
698 #if defined(pdp11)
699 			/* use this if your "long" int indexing is slow */
700 #define	DOXOR(x,y,i)	j=B.b[i]; x^=SPTAB(SPE[0][i],j); y^=SPTAB(SPE[1][i],j);
701 #else
702 			/* use this if "k" is allocated to a register ... */
703 #define	DOXOR(x,y,i)	k=B.b[i]; x^=SPTAB(SPE[0][i],k); y^=SPTAB(SPE[1][i],k);
704 #endif
705 #endif
706 
707 #define	CRUNCH(p0, p1, q0, q1)	\
708 			k = (q0 ^ q1) & SALT;	\
709 			B.b32.i0 = k ^ q0 ^ kp->b32.i0;		\
710 			B.b32.i1 = k ^ q1 ^ kp->b32.i1;		\
711 			kp = (C_block *)((char *)kp+ks_inc);	\
712 							\
713 			DOXOR(p0, p1, 0);		\
714 			DOXOR(p0, p1, 1);		\
715 			DOXOR(p0, p1, 2);		\
716 			DOXOR(p0, p1, 3);		\
717 			DOXOR(p0, p1, 4);		\
718 			DOXOR(p0, p1, 5);		\
719 			DOXOR(p0, p1, 6);		\
720 			DOXOR(p0, p1, 7);
721 
722 			CRUNCH(L0, L1, R0, R1);
723 			CRUNCH(R0, R1, L0, L1);
724 		} while (--loop_count != 0);
725 		kp = (C_block *)((char *)kp-(ks_inc*KS_SIZE));
726 
727 
728 		/* swap L and R */
729 		L0 ^= R0;  L1 ^= R1;
730 		R0 ^= L0;  R1 ^= L1;
731 		L0 ^= R0;  L1 ^= R1;
732 	}
733 
734 	/* store the encrypted (or decrypted) result */
735 	L0 = ((L0 >> 3) & 0x0f0f0f0fL) | ((L1 << 1) & 0xf0f0f0f0L);
736 	L1 = ((R0 >> 3) & 0x0f0f0f0fL) | ((R1 << 1) & 0xf0f0f0f0L);
737 	STORE(L,L0,L1,B);
738 	PERM6464(L,L0,L1,B.b, (C_block *)CF6464);
739 #if defined(MUST_ALIGN)
740 	STORE(L,L0,L1,B);
741 	out[0] = B.b[0]; out[1] = B.b[1]; out[2] = B.b[2]; out[3] = B.b[3];
742 	out[4] = B.b[4]; out[5] = B.b[5]; out[6] = B.b[6]; out[7] = B.b[7];
743 #else
744 	STORE(L,L0,L1,*(C_block *)out);
745 #endif
746 	return (0);
747 }
748 
749 
750 /*
751  * Initialize various tables.  This need only be done once.  It could even be
752  * done at compile time, if the compiler were capable of that sort of thing.
753  */
754 STATIC
755 init_des()
756 {
757 	int i, j;
758 	int32_t k;
759 	int tableno;
760 	static unsigned char perm[64], tmp32[32];	/* "static" for speed */
761 
762 	/*
763 	 * table that converts chars "./0-9A-Za-z"to integers 0-63.
764 	 */
765 	for (i = 0; i < 64; i++)
766 		a64toi[itoa64[i]] = i;
767 
768 	/*
769 	 * PC1ROT - bit reverse, then PC1, then Rotate, then PC2.
770 	 */
771 	for (i = 0; i < 64; i++)
772 		perm[i] = 0;
773 	for (i = 0; i < 64; i++) {
774 		if ((k = PC2[i]) == 0)
775 			continue;
776 		k += Rotates[0]-1;
777 		if ((k%28) < Rotates[0]) k -= 28;
778 		k = PC1[k];
779 		if (k > 0) {
780 			k--;
781 			k = (k|07) - (k&07);
782 			k++;
783 		}
784 		perm[i] = k;
785 	}
786 #ifdef DEBUG
787 	prtab("pc1tab", perm, 8);
788 #endif
789 	init_perm(PC1ROT, perm, 8, 8);
790 
791 	/*
792 	 * PC2ROT - PC2 inverse, then Rotate (once or twice), then PC2.
793 	 */
794 	for (j = 0; j < 2; j++) {
795 		unsigned char pc2inv[64];
796 		for (i = 0; i < 64; i++)
797 			perm[i] = pc2inv[i] = 0;
798 		for (i = 0; i < 64; i++) {
799 			if ((k = PC2[i]) == 0)
800 				continue;
801 			pc2inv[k-1] = i+1;
802 		}
803 		for (i = 0; i < 64; i++) {
804 			if ((k = PC2[i]) == 0)
805 				continue;
806 			k += j;
807 			if ((k%28) <= j) k -= 28;
808 			perm[i] = pc2inv[k];
809 		}
810 #ifdef DEBUG
811 		prtab("pc2tab", perm, 8);
812 #endif
813 		init_perm(PC2ROT[j], perm, 8, 8);
814 	}
815 
816 	/*
817 	 * Bit reverse, then initial permutation, then expansion.
818 	 */
819 	for (i = 0; i < 8; i++) {
820 		for (j = 0; j < 8; j++) {
821 			k = (j < 2)? 0: IP[ExpandTr[i*6+j-2]-1];
822 			if (k > 32)
823 				k -= 32;
824 			else if (k > 0)
825 				k--;
826 			if (k > 0) {
827 				k--;
828 				k = (k|07) - (k&07);
829 				k++;
830 			}
831 			perm[i*8+j] = k;
832 		}
833 	}
834 #ifdef DEBUG
835 	prtab("ietab", perm, 8);
836 #endif
837 	init_perm(IE3264, perm, 4, 8);
838 
839 	/*
840 	 * Compression, then final permutation, then bit reverse.
841 	 */
842 	for (i = 0; i < 64; i++) {
843 		k = IP[CIFP[i]-1];
844 		if (k > 0) {
845 			k--;
846 			k = (k|07) - (k&07);
847 			k++;
848 		}
849 		perm[k-1] = i+1;
850 	}
851 #ifdef DEBUG
852 	prtab("cftab", perm, 8);
853 #endif
854 	init_perm(CF6464, perm, 8, 8);
855 
856 	/*
857 	 * SPE table
858 	 */
859 	for (i = 0; i < 48; i++)
860 		perm[i] = P32Tr[ExpandTr[i]-1];
861 	for (tableno = 0; tableno < 8; tableno++) {
862 		for (j = 0; j < 64; j++)  {
863 			k = (((j >> 0) &01) << 5)|
864 			    (((j >> 1) &01) << 3)|
865 			    (((j >> 2) &01) << 2)|
866 			    (((j >> 3) &01) << 1)|
867 			    (((j >> 4) &01) << 0)|
868 			    (((j >> 5) &01) << 4);
869 			k = S[tableno][k];
870 			k = (((k >> 3)&01) << 0)|
871 			    (((k >> 2)&01) << 1)|
872 			    (((k >> 1)&01) << 2)|
873 			    (((k >> 0)&01) << 3);
874 			for (i = 0; i < 32; i++)
875 				tmp32[i] = 0;
876 			for (i = 0; i < 4; i++)
877 				tmp32[4 * tableno + i] = (k >> i) & 01;
878 			k = 0;
879 			for (i = 24; --i >= 0; )
880 				k = (k<<1) | tmp32[perm[i]-1];
881 			TO_SIX_BIT(SPE[0][tableno][j], k);
882 			k = 0;
883 			for (i = 24; --i >= 0; )
884 				k = (k<<1) | tmp32[perm[i+24]-1];
885 			TO_SIX_BIT(SPE[1][tableno][j], k);
886 		}
887 	}
888 }
889 
890 /*
891  * Initialize "perm" to represent transformation "p", which rearranges
892  * (perhaps with expansion and/or contraction) one packed array of bits
893  * (of size "chars_in" characters) into another array (of size "chars_out"
894  * characters).
895  *
896  * "perm" must be all-zeroes on entry to this routine.
897  */
898 STATIC
899 init_perm(perm, p, chars_in, chars_out)
900 	C_block perm[64/CHUNKBITS][1<<CHUNKBITS];
901 	unsigned char p[64];
902 	int chars_in, chars_out;
903 {
904 	int i, j, k, l;
905 
906 	for (k = 0; k < chars_out*8; k++) {	/* each output bit position */
907 		l = p[k] - 1;		/* where this bit comes from */
908 		if (l < 0)
909 			continue;	/* output bit is always 0 */
910 		i = l>>LGCHUNKBITS;	/* which chunk this bit comes from */
911 		l = 1<<(l&(CHUNKBITS-1));	/* mask for this bit */
912 		for (j = 0; j < (1<<CHUNKBITS); j++) {	/* each chunk value */
913 			if ((j & l) != 0)
914 				perm[i][j].b[k>>3] |= 1<<(k&07);
915 		}
916 	}
917 }
918 
919 /*
920  * "setkey" routine (for backwards compatibility)
921  */
922 int
923 setkey(key)
924 	const char *key;
925 {
926 	int i, j, k;
927 	C_block keyblock;
928 
929 	for (i = 0; i < 8; i++) {
930 		k = 0;
931 		for (j = 0; j < 8; j++) {
932 			k <<= 1;
933 			k |= (unsigned char)*key++;
934 		}
935 		keyblock.b[i] = k;
936 	}
937 	return (des_setkey((char *)keyblock.b));
938 }
939 
940 /*
941  * "encrypt" routine (for backwards compatibility)
942  */
943 int
944 encrypt(block, flag)
945 	char *block;
946 	int flag;
947 {
948 	int i, j, k;
949 	C_block cblock;
950 
951 	for (i = 0; i < 8; i++) {
952 		k = 0;
953 		for (j = 0; j < 8; j++) {
954 			k <<= 1;
955 			k |= (unsigned char)*block++;
956 		}
957 		cblock.b[i] = k;
958 	}
959 	if (des_cipher((char *)&cblock, (char *)&cblock, 0L, (flag ? -1: 1)))
960 		return (1);
961 	for (i = 7; i >= 0; i--) {
962 		k = cblock.b[i];
963 		for (j = 7; j >= 0; j--) {
964 			*--block = k&01;
965 			k >>= 1;
966 		}
967 	}
968 	return (0);
969 }
970 
971 #ifdef DEBUG
972 STATIC
973 prtab(s, t, num_rows)
974 	char *s;
975 	unsigned char *t;
976 	int num_rows;
977 {
978 	int i, j;
979 
980 	(void)printf("%s:\n", s);
981 	for (i = 0; i < num_rows; i++) {
982 		for (j = 0; j < 8; j++) {
983 			 (void)printf("%3d", t[i*8+j]);
984 		}
985 		(void)printf("\n");
986 	}
987 	(void)printf("\n");
988 }
989 #endif
990