xref: /openbsd/games/adventure/save.c (revision 17df1aa7)
1 /*	$OpenBSD: save.c,v 1.8 2009/10/27 23:59:23 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 #include <stdio.h>
39 #include <stdlib.h>
40 #include "hdr.h"
41 #include "extern.h"
42 
43 struct savestruct
44 {
45 	void *address;
46 	int width;
47 };
48 
49 struct savestruct save_array[] =
50 {
51 	{&abbnum, sizeof(abbnum)},
52 	{&attack, sizeof(attack)},
53 	{&blklin, sizeof(blklin)},
54 	{&bonus,  sizeof(bonus)},
55 	{&chloc,  sizeof(chloc)},
56 	{&chloc2, sizeof(chloc2)},
57 	{&clock1, sizeof(clock1)},
58 	{&clock2, sizeof(clock2)},
59 	{&closed, sizeof(closed)},
60 	{&closng, sizeof(closng)},
61 	{&daltlc, sizeof(daltlc)},
62 	{&demo,   sizeof(demo)},
63 	{&detail, sizeof(detail)},
64 	{&dflag,  sizeof(dflag)},
65 	{&dkill,  sizeof(dkill)},
66 	{&dtotal, sizeof(dtotal)},
67 	{&foobar, sizeof(foobar)},
68 	{&gaveup, sizeof(gaveup)},
69 	{&holdng, sizeof(holdng)},
70 	{&iwest,  sizeof(iwest)},
71 	{&k,      sizeof(k)},
72 	{&k2,     sizeof(k2)},
73 	{&knfloc, sizeof(knfloc)},
74 	{&kq,     sizeof(kq)},
75 	{&latncy, sizeof(latncy)},
76 	{&limit,  sizeof(limit)},
77 	{&lmwarn, sizeof(lmwarn)},
78 	{&loc,    sizeof(loc)},
79 	{&maxdie, sizeof(maxdie)},
80 	{&mxscor, sizeof(mxscor)},
81 	{&newloc, sizeof(newloc)},
82 	{&numdie, sizeof(numdie)},
83 	{&obj,    sizeof(obj)},
84 	{&oldlc2, sizeof(oldlc2)},
85 	{&oldloc, sizeof(oldloc)},
86 	{&panic,  sizeof(panic)},
87 	{&savet,  sizeof(savet)},
88 	{&scorng, sizeof(scorng)},
89 	{&spk,    sizeof(spk)},
90 	{&stick,  sizeof(stick)},
91 	{&tally,  sizeof(tally)},
92 	{&tally2, sizeof(tally2)},
93 	{&tkk,    sizeof(tkk)},
94 	{&turns,  sizeof(turns)},
95 	{&verb,   sizeof(verb)},
96 	{&wd1,    sizeof(wd1)},
97 	{&wd2,    sizeof(wd2)},
98 	{&wzdark, sizeof(wzdark)},
99 	{&yea,    sizeof(yea)},
100 	{atloc,   sizeof(atloc)},
101 	{dloc,    sizeof(dloc)},
102 	{dseen,   sizeof(dseen)},
103 	{fixed,   sizeof(fixed)},
104 	{hinted,  sizeof(hinted)},
105 	{linkx,   sizeof(linkx)},
106 	{odloc,   sizeof(odloc)},
107 	{place,   sizeof(place)},
108 	{prop,    sizeof(prop)},
109 	{tk,      sizeof(tk)},
110 
111 	{NULL,    0}
112 };
113 
114 /*
115  * Two passes on data: first to get checksum, second
116  * to output the data using checksum to start random #s
117  */
118 int
119 save(const char *outfile)
120 {
121 	FILE   *out;
122 	struct savestruct *p;
123 	char   *s;
124 	long    sum;
125 	int     i;
126 
127 	crc_start();
128 	for (p = save_array; p->address != NULL; p++)
129 		sum = crc(p->address, p->width);
130 	srandom((int) sum);
131 
132 	if ((out = fopen(outfile, "wb")) == NULL) {
133 		fprintf(stderr,
134 		   "Hmm.  The name \"%s\" appears to be magically blocked.\n",
135 		   outfile);
136 		return 1;
137 	}
138 
139 	fwrite(&sum, sizeof(sum), 1, out);	/* Here's the random() key */
140 	for (p = save_array; p->address != NULL; p++) {
141 		for (s = p->address, i = 0; i < p->width; i++, s++)
142 			*s = (*s ^ random()) & 0xFF;	/* Lightly encrypt */
143 		fwrite(p->address, p->width, 1, out);
144 	}
145 	fclose(out);
146 	return 0;
147 }
148 
149 int
150 restore(const char *infile)
151 {
152 	FILE   *in;
153 	struct savestruct *p;
154 	char   *s;
155 	long    sum, cksum;
156 	int     i;
157 
158 	if ((in = fopen(infile, "rb")) == NULL) {
159 		fprintf(stderr,
160 		   "Hmm.  The file \"%s\" appears to be magically blocked.\n",
161 		   infile);
162 		return 1;
163 	}
164 
165 	fread(&sum, sizeof(sum), 1, in);	/* Get the seed */
166 	srandom((unsigned int) sum);
167 	for (p = save_array; p->address != NULL; p++) {
168 		fread(p->address, p->width, 1, in);
169 		for (s = p->address, i = 0; i < p->width; i++, s++)
170 			*s = (*s ^ random()) & 0xFF;	/* Lightly decrypt */
171 	}
172 	fclose(in);
173 
174 	crc_start();			/* See if she cheated */
175 	for (p = save_array; p->address != NULL; p++)
176 		cksum = crc(p->address, p->width);
177 	if (sum != cksum)		/* Tsk tsk */
178 		return 2;		/* Altered the file */
179 	/* We successfully restored, so this really was a save file */
180 	/* Get rid of the file, but don't bother checking that we did */
181 	return 0;
182 }
183