1/*	$NetBSD: crypt.c,v 1.40 2023/08/14 02:22:35 rin 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. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36#if !defined(lint)
37#if 0
38static char sccsid[] = "@(#)crypt.c	8.1.1.1 (Berkeley) 8/18/93";
39#else
40__RCSID("$NetBSD: crypt.c,v 1.40 2023/08/14 02:22:35 rin Exp $");
41#endif
42#endif /* not lint */
43
44#include <limits.h>
45#include <pwd.h>
46#include <stdlib.h>
47#include <string.h> /* for strcmp */
48#include <unistd.h>
49#if defined(DEBUG) || defined(MAIN) || defined(UNIT_TEST)
50#include <stdio.h>
51#endif
52
53#include "crypt.h"
54
55/*
56 * UNIX password, and DES, encryption.
57 * By Tom Truscott, trt@rti.rti.org,
58 * from algorithms by Robert W. Baldwin and James Gillogly.
59 *
60 * References:
61 * "Mathematical Cryptology for Computer Scientists and Mathematicians,"
62 * by Wayne Patterson, 1987, ISBN 0-8476-7438-X.
63 *
64 * "Password Security: A Case History," R. Morris and Ken Thompson,
65 * Communications of the ACM, vol. 22, pp. 594-597, Nov. 1979.
66 *
67 * "DES will be Totally Insecure within Ten Years," M.E. Hellman,
68 * IEEE Spectrum, vol. 16, pp. 32-39, July 1979.
69 */
70
71/* =====  Configuration ==================== */
72
73/*
74 * define "MUST_ALIGN" if your compiler cannot load/store
75 * long integers at arbitrary (e.g. odd) memory locations.
76 * (Either that or never pass unaligned addresses to des_cipher!)
77 */
78#if !defined(__vax__) && !defined(__i386__)
79#define	MUST_ALIGN
80#endif
81
82#ifdef CHAR_BITS
83#if CHAR_BITS != 8
84	#error C_block structure assumes 8 bit characters
85#endif
86#endif
87
88/*
89 * define "B64" to be the declaration for a 64 bit integer.
90 * XXX this feature is currently unused, see "endian" comment below.
91 */
92#if defined(cray)
93#define	B64	long
94#endif
95#if defined(convex)
96#define	B64	long long
97#endif
98
99/*
100 * define "LARGEDATA" to get faster permutations, by using about 72 kilobytes
101 * of lookup tables.  This speeds up des_setkey() and des_cipher(), but has
102 * little effect on crypt().
103 */
104#if defined(notdef)
105#define	LARGEDATA
106#endif
107
108/* compile with "-DSTATIC=void" when profiling */
109#ifndef STATIC
110#define	STATIC	static void
111#endif
112
113/* ==================================== */
114
115/*
116 * Cipher-block representation (Bob Baldwin):
117 *
118 * DES operates on groups of 64 bits, numbered 1..64 (sigh).  One
119 * representation is to store one bit per byte in an array of bytes.  Bit N of
120 * the NBS spec is stored as the LSB of the Nth byte (index N-1) in the array.
121 * Another representation stores the 64 bits in 8 bytes, with bits 1..8 in the
122 * first byte, 9..16 in the second, and so on.  The DES spec apparently has
123 * bit 1 in the MSB of the first byte, but that is particularly noxious so we
124 * bit-reverse each byte so that bit 1 is the LSB of the first byte, bit 8 is
125 * the MSB of the first byte.  Specifically, the 64-bit input data and key are
126 * converted to LSB format, and the output 64-bit block is converted back into
127 * MSB format.
128 *
129 * DES operates internally on groups of 32 bits which are expanded to 48 bits
130 * by permutation E and shrunk back to 32 bits by the S boxes.  To speed up
131 * the computation, the expansion is applied only once, the expanded
132 * representation is maintained during the encryption, and a compression
133 * permutation is applied only at the end.  To speed up the S-box lookups,
134 * the 48 bits are maintained as eight 6 bit groups, one per byte, which
135 * directly feed the eight S-boxes.  Within each byte, the 6 bits are the
136 * most significant ones.  The low two bits of each byte are zero.  (Thus,
137 * bit 1 of the 48 bit E expansion is stored as the "4"-valued bit of the
138 * first byte in the eight byte representation, bit 2 of the 48 bit value is
139 * the "8"-valued bit, and so on.)  In fact, a combined "SPE"-box lookup is
140 * used, in which the output is the 64 bit result of an S-box lookup which
141 * has been permuted by P and expanded by E, and is ready for use in the next
142 * iteration.  Two 32-bit wide tables, SPE[0] and SPE[1], are used for this
143 * lookup.  Since each byte in the 48 bit path is a multiple of four, indexed
144 * lookup of SPE[0] and SPE[1] is simple and fast.  The key schedule and
145 * "salt" are also converted to this 8*(6+2) format.  The SPE table size is
146 * 8*64*8 = 4K bytes.
147 *
148 * To speed up bit-parallel operations (such as XOR), the 8 byte
149 * representation is "union"ed with 32 bit values "i0" and "i1", and, on
150 * machines which support it, a 64 bit value "b64".  This data structure,
151 * "C_block", has two problems.  First, alignment restrictions must be
152 * honored.  Second, the byte-order (e.g. little-endian or big-endian) of
153 * the architecture becomes visible.
154 *
155 * The byte-order problem is unfortunate, since on the one hand it is good
156 * to have a machine-independent C_block representation (bits 1..8 in the
157 * first byte, etc.), and on the other hand it is good for the LSB of the
158 * first byte to be the LSB of i0.  We cannot have both these things, so we
159 * currently use the "little-endian" representation and avoid any multi-byte
160 * operations that depend on byte order.  This largely precludes use of the
161 * 64-bit datatype since the relative order of i0 and i1 are unknown.  It
162 * also inhibits grouping the SPE table to look up 12 bits at a time.  (The
163 * 12 bits can be stored in a 16-bit field with 3 low-order zeroes and 1
164 * high-order zero, providing fast indexing into a 64-bit wide SPE.)  On the
165 * other hand, 64-bit datatypes are currently rare, and a 12-bit SPE lookup
166 * requires a 128 kilobyte table, so perhaps this is not a big loss.
167 *
168 * Permutation representation (Jim Gillogly):
169 *
170 * A transformation is defined by its effect on each of the 8 bytes of the
171 * 64-bit input.  For each byte we give a 64-bit output that has the bits in
172 * the input distributed appropriately.  The transformation is then the OR
173 * of the 8 sets of 64-bits.  This uses 8*256*8 = 16K bytes of storage for
174 * each transformation.  Unless LARGEDATA is defined, however, a more compact
175 * table is used which looks up 16 4-bit "chunks" rather than 8 8-bit chunks.
176 * The smaller table uses 16*16*8 = 2K bytes for each transformation.  This
177 * is slower but tolerable, particularly for password encryption in which
178 * the SPE transformation is iterated many times.  The small tables total 9K
179 * bytes, the large tables total 72K bytes.
180 *
181 * The transformations used are:
182 * IE3264: MSB->LSB conversion, initial permutation, and expansion.
183 *	This is done by collecting the 32 even-numbered bits and applying
184 *	a 32->64 bit transformation, and then collecting the 32 odd-numbered
185 *	bits and applying the same transformation.  Since there are only
186 *	32 input bits, the IE3264 transformation table is half the size of
187 *	the usual table.
188 * CF6464: Compression, final permutation, and LSB->MSB conversion.
189 *	This is done by two trivial 48->32 bit compressions to obtain
190 *	a 64-bit block (the bit numbering is given in the "CIFP" table)
191 *	followed by a 64->64 bit "cleanup" transformation.  (It would
192 *	be possible to group the bits in the 64-bit block so that 2
193 *	identical 32->32 bit transformations could be used instead,
194 *	saving a factor of 4 in space and possibly 2 in time, but
195 *	byte-ordering and other complications rear their ugly head.
196 *	Similar opportunities/problems arise in the key schedule
197 *	transforms.)
198 * PC1ROT: MSB->LSB, PC1 permutation, rotate, and PC2 permutation.
199 *	This admittedly baroque 64->64 bit transformation is used to
200 *	produce the first code (in 8*(6+2) format) of the key schedule.
201 * PC2ROT[0]: Inverse PC2 permutation, rotate, and PC2 permutation.
202 *	It would be possible to define 15 more transformations, each
203 *	with a different rotation, to generate the entire key schedule.
204 *	To save space, however, we instead permute each code into the
205 *	next by using a transformation that "undoes" the PC2 permutation,
206 *	rotates the code, and then applies PC2.  Unfortunately, PC2
207 *	transforms 56 bits into 48 bits, dropping 8 bits, so PC2 is not
208 *	invertible.  We get around that problem by using a modified PC2
209 *	which retains the 8 otherwise-lost bits in the unused low-order
210 *	bits of each byte.  The low-order bits are cleared when the
211 *	codes are stored into the key schedule.
212 * PC2ROT[1]: Same as PC2ROT[0], but with two rotations.
213 *	This is faster than applying PC2ROT[0] twice,
214 *
215 * The Bell Labs "salt" (Bob Baldwin):
216 *
217 * The salting is a simple permutation applied to the 48-bit result of E.
218 * Specifically, if bit i (1 <= i <= 24) of the salt is set then bits i and
219 * i+24 of the result are swapped.  The salt is thus a 24 bit number, with
220 * 16777216 possible values.  (The original salt was 12 bits and could not
221 * swap bits 13..24 with 36..48.)
222 *
223 * It is possible, but ugly, to warp the SPE table to account for the salt
224 * permutation.  Fortunately, the conditional bit swapping requires only
225 * about four machine instructions and can be done on-the-fly with about an
226 * 8% performance penalty.
227 */
228
229typedef union {
230	unsigned char b[8];
231	struct {
232		int32_t	i0;
233		int32_t	i1;
234	} b32;
235#if defined(B64)
236	B64	b64;
237#endif
238} C_block;
239
240/*
241 * Convert twenty-four-bit long in host-order
242 * to six bits (and 2 low-order zeroes) per char little-endian format.
243 */
244#define	TO_SIX_BIT(rslt, src) {				\
245		C_block cvt;				\
246		cvt.b[0] = src; src >>= 6;		\
247		cvt.b[1] = src; src >>= 6;		\
248		cvt.b[2] = src; src >>= 6;		\
249		cvt.b[3] = src;				\
250		rslt = (cvt.b32.i0 & 0x3f3f3f3fL) << 2;	\
251	}
252
253/*
254 * These macros may someday permit efficient use of 64-bit integers.
255 */
256#define	ZERO(d,d0,d1)			d0 = 0, d1 = 0
257#define	LOAD(d,d0,d1,bl)		d0 = (bl).b32.i0, d1 = (bl).b32.i1
258#define	LOADREG(d,d0,d1,s,s0,s1)	d0 = s0, d1 = s1
259#define	OR(d,d0,d1,bl)			d0 |= (bl).b32.i0, d1 |= (bl).b32.i1
260#define	STORE(s,s0,s1,bl)		(bl).b32.i0 = s0, (bl).b32.i1 = s1
261#define	DCL_BLOCK(d,d0,d1)		int32_t d0, d1
262
263#if defined(LARGEDATA)
264	/* Waste memory like crazy.  Also, do permutations in line */
265#define	LGCHUNKBITS	3
266#define	CHUNKBITS	(1<<LGCHUNKBITS)
267#define	PERM6464(d,d0,d1,cpp,p)				\
268	LOAD(d,d0,d1,(p)[(0<<CHUNKBITS)+(cpp)[0]]);		\
269	OR (d,d0,d1,(p)[(1<<CHUNKBITS)+(cpp)[1]]);		\
270	OR (d,d0,d1,(p)[(2<<CHUNKBITS)+(cpp)[2]]);		\
271	OR (d,d0,d1,(p)[(3<<CHUNKBITS)+(cpp)[3]]);		\
272	OR (d,d0,d1,(p)[(4<<CHUNKBITS)+(cpp)[4]]);		\
273	OR (d,d0,d1,(p)[(5<<CHUNKBITS)+(cpp)[5]]);		\
274	OR (d,d0,d1,(p)[(6<<CHUNKBITS)+(cpp)[6]]);		\
275	OR (d,d0,d1,(p)[(7<<CHUNKBITS)+(cpp)[7]]);
276#define	PERM3264(d,d0,d1,cpp,p)				\
277	LOAD(d,d0,d1,(p)[(0<<CHUNKBITS)+(cpp)[0]]);		\
278	OR (d,d0,d1,(p)[(1<<CHUNKBITS)+(cpp)[1]]);		\
279	OR (d,d0,d1,(p)[(2<<CHUNKBITS)+(cpp)[2]]);		\
280	OR (d,d0,d1,(p)[(3<<CHUNKBITS)+(cpp)[3]]);
281#else
282	/* "small data" */
283#define	LGCHUNKBITS	2
284#define	CHUNKBITS	(1<<LGCHUNKBITS)
285#define	PERM6464(d,d0,d1,cpp,p)				\
286	{ C_block tblk; permute(cpp,&tblk,p,8); LOAD (d,d0,d1,tblk); }
287#define	PERM3264(d,d0,d1,cpp,p)				\
288	{ C_block tblk; permute(cpp,&tblk,p,4); LOAD (d,d0,d1,tblk); }
289#endif /* LARGEDATA */
290
291STATIC	init_des(void);
292STATIC	init_perm(C_block [64/CHUNKBITS][1<<CHUNKBITS],
293		       const unsigned char [64], int, int);
294#ifndef LARGEDATA
295STATIC	permute(const unsigned char *, C_block *, C_block *, int);
296#endif
297#ifdef DEBUG
298STATIC	prtab(const char *, unsigned char *, int);
299#endif
300
301
302#ifndef LARGEDATA
303STATIC
304permute(const unsigned char *cp, C_block *out, C_block *p, int chars_in)
305{
306	DCL_BLOCK(D,D0,D1);
307	C_block *tp;
308	int t;
309
310	ZERO(D,D0,D1);
311	do {
312		t = *cp++;
313		tp = &p[t&0xf]; OR(D,D0,D1,*tp); p += (1<<CHUNKBITS);
314		tp = &p[t>>4];  OR(D,D0,D1,*tp); p += (1<<CHUNKBITS);
315	} while (--chars_in > 0);
316	STORE(D,D0,D1,*out);
317}
318#endif /* LARGEDATA */
319
320
321/* =====  (mostly) Standard DES Tables ==================== */
322
323static const unsigned char IP[] = {	/* initial permutation */
324	58, 50, 42, 34, 26, 18, 10,  2,
325	60, 52, 44, 36, 28, 20, 12,  4,
326	62, 54, 46, 38, 30, 22, 14,  6,
327	64, 56, 48, 40, 32, 24, 16,  8,
328	57, 49, 41, 33, 25, 17,  9,  1,
329	59, 51, 43, 35, 27, 19, 11,  3,
330	61, 53, 45, 37, 29, 21, 13,  5,
331	63, 55, 47, 39, 31, 23, 15,  7,
332};
333
334/* The final permutation is the inverse of IP - no table is necessary */
335
336static const unsigned char ExpandTr[] = {	/* expansion operation */
337	32,  1,  2,  3,  4,  5,
338	 4,  5,  6,  7,  8,  9,
339	 8,  9, 10, 11, 12, 13,
340	12, 13, 14, 15, 16, 17,
341	16, 17, 18, 19, 20, 21,
342	20, 21, 22, 23, 24, 25,
343	24, 25, 26, 27, 28, 29,
344	28, 29, 30, 31, 32,  1,
345};
346
347static const unsigned char PC1[] = {	/* permuted choice table 1 */
348	57, 49, 41, 33, 25, 17,  9,
349	 1, 58, 50, 42, 34, 26, 18,
350	10,  2, 59, 51, 43, 35, 27,
351	19, 11,  3, 60, 52, 44, 36,
352
353	63, 55, 47, 39, 31, 23, 15,
354	 7, 62, 54, 46, 38, 30, 22,
355	14,  6, 61, 53, 45, 37, 29,
356	21, 13,  5, 28, 20, 12,  4,
357};
358
359static const unsigned char Rotates[] = {/* PC1 rotation schedule */
360	1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1,
361};
362
363/* note: each "row" of PC2 is left-padded with bits that make it invertible */
364static const unsigned char PC2[] = {	/* permuted choice table 2 */
365	 9, 18,    14, 17, 11, 24,  1,  5,
366	22, 25,     3, 28, 15,  6, 21, 10,
367	35, 38,    23, 19, 12,  4, 26,  8,
368	43, 54,    16,  7, 27, 20, 13,  2,
369
370	 0,  0,    41, 52, 31, 37, 47, 55,
371	 0,  0,    30, 40, 51, 45, 33, 48,
372	 0,  0,    44, 49, 39, 56, 34, 53,
373	 0,  0,    46, 42, 50, 36, 29, 32,
374};
375
376static const unsigned char S[8][64] = {	/* 48->32 bit substitution tables */
377					/* S[1]			*/
378	{ 14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7,
379	   0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8,
380	   4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0,
381	  15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13 },
382					/* S[2]			*/
383	{ 15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10,
384	   3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5,
385	   0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15,
386	  13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9 },
387					/* S[3]			*/
388	{ 10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8,
389	  13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1,
390	  13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7,
391	   1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12 },
392					/* S[4]			*/
393	{  7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15,
394	  13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9,
395	  10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4,
396	   3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14 },
397					/* S[5]			*/
398	{  2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9,
399	  14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6,
400	   4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14,
401	  11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3 },
402					/* S[6]			*/
403	{ 12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11,
404	  10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8,
405	   9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6,
406	   4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13 },
407					/* S[7]			*/
408	{  4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1,
409	  13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6,
410	   1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2,
411	   6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12 },
412					/* S[8]			*/
413	{ 13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7,
414	   1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2,
415	   7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8,
416	   2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11 }
417};
418
419static const unsigned char P32Tr[] = {	/* 32-bit permutation function */
420	16,  7, 20, 21,
421	29, 12, 28, 17,
422	 1, 15, 23, 26,
423	 5, 18, 31, 10,
424	 2,  8, 24, 14,
425	32, 27,  3,  9,
426	19, 13, 30,  6,
427	22, 11,  4, 25,
428};
429
430static const unsigned char CIFP[] = {	/* compressed/interleaved permutation */
431	 1,  2,  3,  4,   17, 18, 19, 20,
432	 5,  6,  7,  8,   21, 22, 23, 24,
433	 9, 10, 11, 12,   25, 26, 27, 28,
434	13, 14, 15, 16,   29, 30, 31, 32,
435
436	33, 34, 35, 36,   49, 50, 51, 52,
437	37, 38, 39, 40,   53, 54, 55, 56,
438	41, 42, 43, 44,   57, 58, 59, 60,
439	45, 46, 47, 48,   61, 62, 63, 64,
440};
441
442static const unsigned char itoa64[] =		/* 0..63 => ascii-64 */
443	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
444
445
446/* =====  Tables that are initialized at run time  ==================== */
447
448
449/* Initial key schedule permutation */
450static C_block	PC1ROT[64/CHUNKBITS][1<<CHUNKBITS];
451
452/* Subsequent key schedule rotation permutations */
453static C_block	PC2ROT[2][64/CHUNKBITS][1<<CHUNKBITS];
454
455/* Initial permutation/expansion table */
456static C_block	IE3264[32/CHUNKBITS][1<<CHUNKBITS];
457
458/* Table that combines the S, P, and E operations.  */
459static int32_t SPE[2][8][64];
460
461/* compressed/interleaved => final permutation table */
462static C_block	CF6464[64/CHUNKBITS][1<<CHUNKBITS];
463
464
465/* ==================================== */
466
467
468static C_block	constdatablock;			/* encryption constant */
469static char	cryptresult[1+4+4+11+1];	/* encrypted result */
470
471/*
472 * We match the behavior of UFC-crypt on systems where "char" is signed by
473 * default (the majority), regardless of char's signedness on our system.
474 */
475static inline int
476ascii_to_bin(char ch)
477{
478	signed char sch = ch;
479	int retval;
480
481	if (sch >= 'a')
482		retval = sch - ('a' - 38);
483	else if (sch >= 'A')
484		retval = sch - ('A' - 12);
485	else
486		retval = sch - '.';
487
488	return retval & 0x3f;
489}
490
491/*
492 * When we choose to "support" invalid salts, nevertheless disallow those
493 * containing characters that would violate the passwd file format.
494 */
495static inline int
496ascii_is_unsafe(char ch)
497{
498	return !ch || ch == '\n' || ch == ':';
499}
500
501/*
502 * We extract the scheme from setting str to allow for
503 * full scheme name comparison
504 * Updated to reflect alc suggestion(s)
505 *
506 * returns boolean 0 on failure, 1 on success,
507 */
508static int
509nondes_scheme_substr(const char * setting,char * scheme, unsigned int len)
510{
511	const char * start;
512	const char * sep;
513
514	/* initialize head pointer */
515	start = setting;
516
517	/* clear out scheme buffer regardless of result */
518	memset(scheme, 0, len);
519
520	/* make sure we are working on non-des scheme string */
521	if (*start != _PASSWORD_NONDES) {
522		return 0;
523	}
524
525	/* increment passed initial _PASSWORD_NONDES */
526	start++;
527
528	if ((sep = memchr(start, _PASSWORD_NONDES,len-1)) == NULL) {
529		return 0;
530	}
531
532	/* if empty string, we are done */
533	if (sep == start) {
534		return 1;
535	}
536
537	/* copy scheme substr to buffer */
538	memcpy(scheme, start, (size_t)(sep - start));
539
540	return 1;
541}
542
543/*
544 * Return a pointer to static data consisting of the "setting"
545 * followed by an encryption produced by the "key" and "setting".
546 */
547static char *
548__crypt(const char *key, const char *setting)
549{
550	char *encp;
551	char scheme[12];
552	int32_t i;
553	int t;
554	int r;
555	int32_t salt;
556	int num_iter, salt_size;
557	C_block keyblock, rsltblock;
558
559	/* Non-DES encryption schemes hook in here. */
560	if (setting[0] == _PASSWORD_NONDES) {
561		r = nondes_scheme_substr(
562			setting, scheme, sizeof(scheme));
563
564		/* return NULL if we are unable to extract substring */
565		if (!r) {
566			return NULL;
567		}
568
569		/* $2a$ found in bcrypt.c:encode_salt  */
570		if (strcmp(scheme, "2a") == 0) {
571			return (__bcrypt(key, setting));
572		} else if (strcmp(scheme, "sha1") == 0) {
573		     /* $sha1$ found in crypt.h:SHA1_MAGIC */
574			return (__crypt_sha1(key, setting));
575		} else if (strcmp(scheme, "1") == 0) {
576		     /* $1$ found in pw_gensalt.c:__gensalt_md5 */
577			return (__md5crypt(key, setting));
578#ifdef HAVE_ARGON2
579		/* explicit argon2 variant */
580		} else if (strcmp(scheme, "argon2id") == 0) {
581		     /* $argon2id$ found in pw_gensalt.c:__gensalt_argon2 */
582			return (__crypt_argon2(key, setting));
583		} else if (strcmp(scheme, "argon2i") == 0) {
584		     /* $argon2i$ found in pw_gensalt.c:__gensalt_argon2 */
585			return (__crypt_argon2(key, setting));
586		} else if (strcmp(scheme, "argon2d") == 0) {
587		     /* $argon2d$ found in pw_gensalt.c:__gensalt_argon2 */
588			return (__crypt_argon2(key, setting));
589#endif /* HAVE_ARGON2 */
590		} else {
591		     /* invalid scheme, including empty string */
592			return NULL;
593		}
594	}
595	/* End non-DES handling */
596
597	for (i = 0; i < 8; i++) {
598		if ((t = 2*(unsigned char)(*key)) != 0)
599			key++;
600		keyblock.b[i] = t;
601	}
602	if (des_setkey((char *)keyblock.b))
603		return (NULL);
604
605	encp = &cryptresult[0];
606	switch (*setting) {
607	case _PASSWORD_EFMT1:
608		/*
609		 * Involve the rest of the password 8 characters at a time.
610		 */
611		while (*key) {
612			if (des_cipher((char *)(void *)&keyblock,
613			    (char *)(void *)&keyblock, 0L, 1))
614				return (NULL);
615			for (i = 0; i < 8; i++) {
616				if ((t = 2*(unsigned char)(*key)) != 0)
617					key++;
618				keyblock.b[i] ^= t;
619			}
620			if (des_setkey((char *)keyblock.b))
621				return (NULL);
622		}
623
624		*encp++ = *setting++;
625
626		/* get iteration count */
627		num_iter = 0;
628		for (i = 4; --i >= 0; ) {
629			int value = ascii_to_bin(setting[i]);
630			if (itoa64[value] != setting[i])
631				return NULL;
632			encp[i] = setting[i];
633			num_iter = (num_iter << 6) | value;
634		}
635		if (num_iter == 0)
636			return NULL;
637		setting += 4;
638		encp += 4;
639		salt_size = 4;
640		break;
641	default:
642		num_iter = 25;
643		salt_size = 2;
644		if (ascii_is_unsafe(setting[0]) || ascii_is_unsafe(setting[1]))
645			return NULL;
646	}
647
648	salt = 0;
649	for (i = salt_size; --i >= 0; ) {
650		int value = ascii_to_bin(setting[i]);
651		if (salt_size > 2 && itoa64[value] != setting[i])
652			return NULL;
653		encp[i] = setting[i];
654		salt = (salt << 6) | value;
655	}
656	encp += salt_size;
657	if (des_cipher((char *)(void *)&constdatablock,
658	    (char *)(void *)&rsltblock, salt, num_iter))
659		return (NULL);
660
661	/*
662	 * Encode the 64 cipher bits as 11 ascii characters.
663	 */
664	i = ((int32_t)((rsltblock.b[0]<<8) | rsltblock.b[1])<<8) |
665	    rsltblock.b[2];
666	encp[3] = itoa64[i&0x3f];	i >>= 6;
667	encp[2] = itoa64[i&0x3f];	i >>= 6;
668	encp[1] = itoa64[i&0x3f];	i >>= 6;
669	encp[0] = itoa64[i];		encp += 4;
670	i = ((int32_t)((rsltblock.b[3]<<8) | rsltblock.b[4])<<8) |
671	    rsltblock.b[5];
672	encp[3] = itoa64[i&0x3f];	i >>= 6;
673	encp[2] = itoa64[i&0x3f];	i >>= 6;
674	encp[1] = itoa64[i&0x3f];	i >>= 6;
675	encp[0] = itoa64[i];		encp += 4;
676	i = ((int32_t)((rsltblock.b[6])<<8) | rsltblock.b[7])<<2;
677	encp[2] = itoa64[i&0x3f];	i >>= 6;
678	encp[1] = itoa64[i&0x3f];	i >>= 6;
679	encp[0] = itoa64[i];
680
681	encp[3] = 0;
682
683	return (cryptresult);
684}
685
686char *
687crypt(const char *key, const char *salt)
688{
689	char *res = __crypt(key, salt);
690
691	if (res)
692		return res;
693	/* How do I handle errors ? Return "*0" or "*1" */
694	return __UNCONST(salt[0] == '*' && salt[1] == '0' ? "*1" : "*0");
695}
696
697/*
698 * The Key Schedule, filled in by des_setkey() or setkey().
699 */
700#define	KS_SIZE	16
701static C_block	KS[KS_SIZE];
702
703/*
704 * Set up the key schedule from the key.
705 */
706int
707des_setkey(const char *key)
708{
709	DCL_BLOCK(K, K0, K1);
710	C_block *help, *ptabp;
711	int i;
712	static int des_ready = 0;
713
714	if (!des_ready) {
715		init_des();
716		des_ready = 1;
717	}
718
719	PERM6464(K,K0,K1,(const unsigned char *)key,(C_block *)PC1ROT);
720	help = &KS[0];
721	STORE(K&~0x03030303L, K0&~0x03030303L, K1, *help);
722	for (i = 1; i < 16; i++) {
723		help++;
724		STORE(K,K0,K1,*help);
725		ptabp = (C_block *)PC2ROT[Rotates[i]-1];
726		PERM6464(K,K0,K1,(const unsigned char *)help,ptabp);
727		STORE(K&~0x03030303L, K0&~0x03030303L, K1, *help);
728	}
729	return (0);
730}
731
732/*
733 * Encrypt (or decrypt if num_iter < 0) the 8 chars at "in" with abs(num_iter)
734 * iterations of DES, using the given 24-bit salt and the pre-computed key
735 * schedule, and store the resulting 8 chars at "out" (in == out is permitted).
736 *
737 * NOTE: the performance of this routine is critically dependent on your
738 * compiler and machine architecture.
739 */
740int
741des_cipher(const char *in, char *out, long salt, int num_iter)
742{
743	/* variables that we want in registers, most important first */
744#if defined(pdp11)
745	int j;
746#endif
747	int32_t L0, L1, R0, R1, k;
748	C_block *kp;
749	int ks_inc, loop_count;
750	C_block B;
751
752	L0 = salt;
753	TO_SIX_BIT(salt, L0);	/* convert to 4*(6+2) format */
754
755#if defined(__vax__) || defined(pdp11)
756	salt = ~salt;	/* "x &~ y" is faster than "x & y". */
757#define	SALT (~salt)
758#else
759#define	SALT salt
760#endif
761
762#if defined(MUST_ALIGN)
763	B.b[0] = in[0]; B.b[1] = in[1]; B.b[2] = in[2]; B.b[3] = in[3];
764	B.b[4] = in[4]; B.b[5] = in[5]; B.b[6] = in[6]; B.b[7] = in[7];
765	LOAD(L,L0,L1,B);
766#else
767	LOAD(L,L0,L1,*(const C_block *)in);
768#endif
769	LOADREG(R,R0,R1,L,L0,L1);
770	L0 &= 0x55555555L;
771	L1 &= 0x55555555L;
772	L0 = ((uint32_t)L0 << 1) | L1;	/* L0 is the even-numbered input bits */
773	R0 &= 0xaaaaaaaaL;
774	R1 = ((uint32_t)R1 >> 1) & 0x55555555L;
775	L1 = R0 | R1;		/* L1 is the odd-numbered input bits */
776	STORE(L,L0,L1,B);
777	PERM3264(L,L0,L1,B.b,  (C_block *)IE3264);	/* even bits */
778	PERM3264(R,R0,R1,B.b+4,(C_block *)IE3264);	/* odd bits */
779
780	if (num_iter >= 0)
781	{		/* encryption */
782		kp = &KS[0];
783		ks_inc  = sizeof(*kp);
784	}
785	else
786	{		/* decryption */
787		num_iter = -num_iter;
788		kp = &KS[KS_SIZE-1];
789		ks_inc  = -(long)sizeof(*kp);
790	}
791
792	while (--num_iter >= 0) {
793		loop_count = 8;
794		do {
795
796#define	SPTAB(t, i) \
797	    (*(int32_t *)((unsigned char *)t + i*(sizeof(int32_t)/4)))
798#if defined(gould)
799			/* use this if B.b[i] is evaluated just once ... */
800#define	DOXOR(x,y,i)	x^=SPTAB(SPE[0][i],B.b[i]); y^=SPTAB(SPE[1][i],B.b[i]);
801#else
802#if defined(pdp11)
803			/* use this if your "long" int indexing is slow */
804#define	DOXOR(x,y,i)	j=B.b[i]; x^=SPTAB(SPE[0][i],j); y^=SPTAB(SPE[1][i],j);
805#else
806			/* use this if "k" is allocated to a register ... */
807#define	DOXOR(x,y,i)	k=B.b[i]; x^=SPTAB(SPE[0][i],k); y^=SPTAB(SPE[1][i],k);
808#endif
809#endif
810
811#define	CRUNCH(p0, p1, q0, q1)	\
812			k = (q0 ^ q1) & SALT;	\
813			B.b32.i0 = k ^ q0 ^ kp->b32.i0;		\
814			B.b32.i1 = k ^ q1 ^ kp->b32.i1;		\
815			kp = (C_block *)((char *)kp+ks_inc);	\
816							\
817			DOXOR(p0, p1, 0);		\
818			DOXOR(p0, p1, 1);		\
819			DOXOR(p0, p1, 2);		\
820			DOXOR(p0, p1, 3);		\
821			DOXOR(p0, p1, 4);		\
822			DOXOR(p0, p1, 5);		\
823			DOXOR(p0, p1, 6);		\
824			DOXOR(p0, p1, 7);
825
826			CRUNCH(L0, L1, R0, R1);
827			CRUNCH(R0, R1, L0, L1);
828		} while (--loop_count != 0);
829		kp = (C_block *)((char *)kp-(ks_inc*KS_SIZE));
830
831
832		/* swap L and R */
833		L0 ^= R0;  L1 ^= R1;
834		R0 ^= L0;  R1 ^= L1;
835		L0 ^= R0;  L1 ^= R1;
836	}
837
838	/* store the encrypted (or decrypted) result */
839	L0 = (((uint32_t)L0 >> 3) & 0x0f0f0f0fL) | (((uint32_t)L1 << 1) & 0xf0f0f0f0L);
840	L1 = (((uint32_t)R0 >> 3) & 0x0f0f0f0fL) | (((uint32_t)R1 << 1) & 0xf0f0f0f0L);
841	STORE(L,L0,L1,B);
842	PERM6464(L,L0,L1,B.b, (C_block *)CF6464);
843#if defined(MUST_ALIGN)
844	STORE(L,L0,L1,B);
845	out[0] = B.b[0]; out[1] = B.b[1]; out[2] = B.b[2]; out[3] = B.b[3];
846	out[4] = B.b[4]; out[5] = B.b[5]; out[6] = B.b[6]; out[7] = B.b[7];
847#else
848	STORE(L,L0,L1,*(C_block *)out);
849#endif
850	return (0);
851}
852
853
854/*
855 * Initialize various tables.  This need only be done once.  It could even be
856 * done at compile time, if the compiler were capable of that sort of thing.
857 */
858STATIC
859init_des(void)
860{
861	int i, j;
862	int32_t k;
863	int tableno;
864	static unsigned char perm[64], tmp32[32];	/* "static" for speed */
865
866	/*
867	 * PC1ROT - bit reverse, then PC1, then Rotate, then PC2.
868	 */
869	for (i = 0; i < 64; i++)
870		perm[i] = 0;
871	for (i = 0; i < 64; i++) {
872		if ((k = PC2[i]) == 0)
873			continue;
874		k += Rotates[0]-1;
875		if ((k%28) < Rotates[0]) k -= 28;
876		k = PC1[k];
877		if (k > 0) {
878			k--;
879			k = (k|07) - (k&07);
880			k++;
881		}
882		perm[i] = k;
883	}
884#ifdef DEBUG
885	prtab("pc1tab", perm, 8);
886#endif
887	init_perm(PC1ROT, perm, 8, 8);
888
889	/*
890	 * PC2ROT - PC2 inverse, then Rotate (once or twice), then PC2.
891	 */
892	for (j = 0; j < 2; j++) {
893		unsigned char pc2inv[64];
894		for (i = 0; i < 64; i++)
895			perm[i] = pc2inv[i] = 0;
896		for (i = 0; i < 64; i++) {
897			if ((k = PC2[i]) == 0)
898				continue;
899			pc2inv[k-1] = i+1;
900		}
901		for (i = 0; i < 64; i++) {
902			if ((k = PC2[i]) == 0)
903				continue;
904			k += j;
905			if ((k%28) <= j) k -= 28;
906			perm[i] = pc2inv[k];
907		}
908#ifdef DEBUG
909		prtab("pc2tab", perm, 8);
910#endif
911		init_perm(PC2ROT[j], perm, 8, 8);
912	}
913
914	/*
915	 * Bit reverse, then initial permutation, then expansion.
916	 */
917	for (i = 0; i < 8; i++) {
918		for (j = 0; j < 8; j++) {
919			k = (j < 2)? 0: IP[ExpandTr[i*6+j-2]-1];
920			if (k > 32)
921				k -= 32;
922			else if (k > 0)
923				k--;
924			if (k > 0) {
925				k--;
926				k = (k|07) - (k&07);
927				k++;
928			}
929			perm[i*8+j] = k;
930		}
931	}
932#ifdef DEBUG
933	prtab("ietab", perm, 8);
934#endif
935	init_perm(IE3264, perm, 4, 8);
936
937	/*
938	 * Compression, then final permutation, then bit reverse.
939	 */
940	for (i = 0; i < 64; i++) {
941		k = IP[CIFP[i]-1];
942		if (k > 0) {
943			k--;
944			k = (k|07) - (k&07);
945			k++;
946		}
947		perm[k-1] = i+1;
948	}
949#ifdef DEBUG
950	prtab("cftab", perm, 8);
951#endif
952	init_perm(CF6464, perm, 8, 8);
953
954	/*
955	 * SPE table
956	 */
957	for (i = 0; i < 48; i++)
958		perm[i] = P32Tr[ExpandTr[i]-1];
959	for (tableno = 0; tableno < 8; tableno++) {
960		for (j = 0; j < 64; j++)  {
961			k = (((j >> 0) &01) << 5)|
962			    (((j >> 1) &01) << 3)|
963			    (((j >> 2) &01) << 2)|
964			    (((j >> 3) &01) << 1)|
965			    (((j >> 4) &01) << 0)|
966			    (((j >> 5) &01) << 4);
967			k = S[tableno][k];
968			k = (((k >> 3)&01) << 0)|
969			    (((k >> 2)&01) << 1)|
970			    (((k >> 1)&01) << 2)|
971			    (((k >> 0)&01) << 3);
972			for (i = 0; i < 32; i++)
973				tmp32[i] = 0;
974			for (i = 0; i < 4; i++)
975				tmp32[4 * tableno + i] = (k >> i) & 01;
976			k = 0;
977			for (i = 24; --i >= 0; )
978				k = (k<<1) | tmp32[perm[i]-1];
979			TO_SIX_BIT(SPE[0][tableno][j], k);
980			k = 0;
981			for (i = 24; --i >= 0; )
982				k = (k<<1) | tmp32[perm[i+24]-1];
983			TO_SIX_BIT(SPE[1][tableno][j], k);
984		}
985	}
986}
987
988/*
989 * Initialize "perm" to represent transformation "p", which rearranges
990 * (perhaps with expansion and/or contraction) one packed array of bits
991 * (of size "chars_in" characters) into another array (of size "chars_out"
992 * characters).
993 *
994 * "perm" must be all-zeroes on entry to this routine.
995 */
996STATIC
997init_perm(C_block perm[64/CHUNKBITS][1<<CHUNKBITS], const unsigned char p[64],
998    int chars_in, int chars_out)
999{
1000	int i, j, k, l;
1001
1002	for (k = 0; k < chars_out*8; k++) {	/* each output bit position */
1003		l = p[k] - 1;		/* where this bit comes from */
1004		if (l < 0)
1005			continue;	/* output bit is always 0 */
1006		i = l>>LGCHUNKBITS;	/* which chunk this bit comes from */
1007		l = 1<<(l&(CHUNKBITS-1));	/* mask for this bit */
1008		for (j = 0; j < (1<<CHUNKBITS); j++) {	/* each chunk value */
1009			if ((j & l) != 0)
1010				perm[i][j].b[k>>3] |= 1<<(k&07);
1011		}
1012	}
1013}
1014
1015/*
1016 * "setkey" routine (for backwards compatibility)
1017 */
1018int
1019setkey(const char *key)
1020{
1021	int i, j, k;
1022	C_block keyblock;
1023
1024	for (i = 0; i < 8; i++) {
1025		k = 0;
1026		for (j = 0; j < 8; j++) {
1027			k <<= 1;
1028			k |= (unsigned char)*key++;
1029		}
1030		keyblock.b[i] = k;
1031	}
1032	return (des_setkey((char *)keyblock.b));
1033}
1034
1035/*
1036 * "encrypt" routine (for backwards compatibility)
1037 */
1038int
1039encrypt(char *block, int flag)
1040{
1041	int i, j, k;
1042	C_block cblock;
1043
1044	for (i = 0; i < 8; i++) {
1045		k = 0;
1046		for (j = 0; j < 8; j++) {
1047			k <<= 1;
1048			k |= (unsigned char)*block++;
1049		}
1050		cblock.b[i] = k;
1051	}
1052	if (des_cipher((char *)&cblock, (char *)&cblock, 0L, (flag ? -1: 1)))
1053		return (1);
1054	for (i = 7; i >= 0; i--) {
1055		k = cblock.b[i];
1056		for (j = 7; j >= 0; j--) {
1057			*--block = k&01;
1058			k >>= 1;
1059		}
1060	}
1061	return (0);
1062}
1063
1064#ifdef DEBUG
1065STATIC
1066prtab(const char *s, unsigned char *t, int num_rows)
1067{
1068	int i, j;
1069
1070	(void)printf("%s:\n", s);
1071	for (i = 0; i < num_rows; i++) {
1072		for (j = 0; j < 8; j++) {
1073			 (void)printf("%3d", t[i*8+j]);
1074		}
1075		(void)printf("\n");
1076	}
1077	(void)printf("\n");
1078}
1079#endif
1080
1081#if defined(MAIN) || defined(UNIT_TEST)
1082#include <err.h>
1083
1084int
1085main(int argc, char *argv[])
1086{
1087	if (argc < 2) {
1088		fprintf(stderr, "Usage: %s password [salt]\n", getprogname());
1089		return EXIT_FAILURE;
1090	}
1091
1092	printf("%s\n", crypt(argv[1], (argc > 2) ? argv[2] : argv[1]));
1093	return EXIT_SUCCESS;
1094}
1095#endif
1096