xref: /openbsd/games/adventure/save.c (revision 404b540a)
1 /*	$OpenBSD: save.c,v 1.7 2004/07/09 15:59:26 deraadt Exp $	*/
2 /*	$NetBSD: save.c,v 1.2 1995/03/21 12:05:08 cgd Exp $	*/
3 
4 /*-
5  * Copyright (c) 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * The game adventure was originally written in Fortran by Will Crowther
9  * and Don Woods.  It was later translated to C and enhanced by Jim
10  * Gillogly.  This code is derived from software contributed to Berkeley
11  * by Jim Gillogly at The Rand Corporation.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. 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 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)save.c	8.1 (Berkeley) 5/31/93";
41 #else
42 static char rcsid[] = "$OpenBSD: save.c,v 1.7 2004/07/09 15:59:26 deraadt Exp $";
43 #endif
44 #endif /* not lint */
45 
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include "hdr.h"
49 #include "extern.h"
50 
51 struct savestruct
52 {
53 	void *address;
54 	int width;
55 };
56 
57 struct savestruct save_array[] =
58 {
59 	{&abbnum, sizeof(abbnum)},
60 	{&attack, sizeof(attack)},
61 	{&blklin, sizeof(blklin)},
62 	{&bonus,  sizeof(bonus)},
63 	{&chloc,  sizeof(chloc)},
64 	{&chloc2, sizeof(chloc2)},
65 	{&clock1, sizeof(clock1)},
66 	{&clock2, sizeof(clock2)},
67 	{&closed, sizeof(closed)},
68 	{&closng, sizeof(closng)},
69 	{&daltlc, sizeof(daltlc)},
70 	{&demo,   sizeof(demo)},
71 	{&detail, sizeof(detail)},
72 	{&dflag,  sizeof(dflag)},
73 	{&dkill,  sizeof(dkill)},
74 	{&dtotal, sizeof(dtotal)},
75 	{&foobar, sizeof(foobar)},
76 	{&gaveup, sizeof(gaveup)},
77 	{&holdng, sizeof(holdng)},
78 	{&iwest,  sizeof(iwest)},
79 	{&k,      sizeof(k)},
80 	{&k2,     sizeof(k2)},
81 	{&knfloc, sizeof(knfloc)},
82 	{&kq,     sizeof(kq)},
83 	{&latncy, sizeof(latncy)},
84 	{&limit,  sizeof(limit)},
85 	{&lmwarn, sizeof(lmwarn)},
86 	{&loc,    sizeof(loc)},
87 	{&maxdie, sizeof(maxdie)},
88 	{&mxscor, sizeof(mxscor)},
89 	{&newloc, sizeof(newloc)},
90 	{&numdie, sizeof(numdie)},
91 	{&obj,    sizeof(obj)},
92 	{&oldlc2, sizeof(oldlc2)},
93 	{&oldloc, sizeof(oldloc)},
94 	{&panic,  sizeof(panic)},
95 	{&savet,  sizeof(savet)},
96 	{&scorng, sizeof(scorng)},
97 	{&spk,    sizeof(spk)},
98 	{&stick,  sizeof(stick)},
99 	{&tally,  sizeof(tally)},
100 	{&tally2, sizeof(tally2)},
101 	{&tkk,    sizeof(tkk)},
102 	{&turns,  sizeof(turns)},
103 	{&verb,   sizeof(verb)},
104 	{&wd1,    sizeof(wd1)},
105 	{&wd2,    sizeof(wd2)},
106 	{&wzdark, sizeof(wzdark)},
107 	{&yea,    sizeof(yea)},
108 	{atloc,   sizeof(atloc)},
109 	{dloc,    sizeof(dloc)},
110 	{dseen,   sizeof(dseen)},
111 	{fixed,   sizeof(fixed)},
112 	{hinted,  sizeof(hinted)},
113 	{linkx,   sizeof(linkx)},
114 	{odloc,   sizeof(odloc)},
115 	{place,   sizeof(place)},
116 	{prop,    sizeof(prop)},
117 	{tk,      sizeof(tk)},
118 
119 	{NULL,    0}
120 };
121 
122 /*
123  * Two passes on data: first to get checksum, second
124  * to output the data using checksum to start random #s
125  */
126 int
127 save(const char *outfile)
128 {
129 	FILE   *out;
130 	struct savestruct *p;
131 	char   *s;
132 	long    sum;
133 	int     i;
134 
135 	crc_start();
136 	for (p = save_array; p->address != NULL; p++)
137 		sum = crc(p->address, p->width);
138 	srandom((int) sum);
139 
140 	if ((out = fopen(outfile, "wb")) == NULL) {
141 		fprintf(stderr,
142 		   "Hmm.  The name \"%s\" appears to be magically blocked.\n",
143 		   outfile);
144 		return 1;
145 	}
146 
147 	fwrite(&sum, sizeof(sum), 1, out);	/* Here's the random() key */
148 	for (p = save_array; p->address != NULL; p++) {
149 		for (s = p->address, i = 0; i < p->width; i++, s++)
150 			*s = (*s ^ random()) & 0xFF;	/* Lightly encrypt */
151 		fwrite(p->address, p->width, 1, out);
152 	}
153 	fclose(out);
154 	return 0;
155 }
156 
157 int
158 restore(const char *infile)
159 {
160 	FILE   *in;
161 	struct savestruct *p;
162 	char   *s;
163 	long    sum, cksum;
164 	int     i;
165 
166 	if ((in = fopen(infile, "rb")) == NULL) {
167 		fprintf(stderr,
168 		   "Hmm.  The file \"%s\" appears to be magically blocked.\n",
169 		   infile);
170 		return 1;
171 	}
172 
173 	fread(&sum, sizeof(sum), 1, in);	/* Get the seed */
174 	srandom((unsigned int) sum);
175 	for (p = save_array; p->address != NULL; p++) {
176 		fread(p->address, p->width, 1, in);
177 		for (s = p->address, i = 0; i < p->width; i++, s++)
178 			*s = (*s ^ random()) & 0xFF;	/* Lightly decrypt */
179 	}
180 	fclose(in);
181 
182 	crc_start();			/* See if she cheated */
183 	for (p = save_array; p->address != NULL; p++)
184 		cksum = crc(p->address, p->width);
185 	if (sum != cksum)		/* Tsk tsk */
186 		return 2;		/* Altered the file */
187 	/* We successfully restored, so this really was a save file */
188 	/* Get rid of the file, but don't bother checking that we did */
189 	return 0;
190 }
191