xref: /plan9-contrib/sys/src/libauthsrv/readnvram.c (revision 6a9fc400c33447ef5e1cda7185cb4de2c8e8010e)
1 #include <u.h>
2 #include <libc.h>
3 #include <authsrv.h>
4 
5 static long	finddosfile(int, char*);
6 
7 static int
8 check(void *x, int len, uchar sum, char *msg)
9 {
10 	if(nvcsum(x, len) == sum)
11 		return 0;
12 	memset(x, 0, len);
13 	fprint(2, "%s\n", msg);
14 	return 1;
15 }
16 
17 /*
18  *  get key info out of nvram.  since there isn't room in the PC's nvram use
19  *  a disk partition there.
20  */
21 static struct {
22 	char *cputype;
23 	char *file;
24 	int off;
25 	int len;
26 } nvtab[] = {
27 	"sparc", "#r/nvram", 1024+850, sizeof(Nvrsafe),
28 	"pc", "#S/sdC0/nvram", 0, sizeof(Nvrsafe),
29 	"pc", "#S/sdC0/9fat", -1, sizeof(Nvrsafe),
30 	"pc", "#S/sd00/nvram", 0, sizeof(Nvrsafe),
31 	"pc", "#S/sd00/9fat", -1, sizeof(Nvrsafe),
32 	"pc", "#f/fd0disk", -1, 512,	/* 512: #f requires whole sector reads */
33 	"pc", "#f/fd1disk", -1, 512,
34 	"mips", "#r/nvram", 1024+900, sizeof(Nvrsafe),
35 	"power", "#F/flash/flash0", 0x300000, sizeof(Nvrsafe),
36 	"power", "#r/nvram", 4352, sizeof(Nvrsafe),	/* OK for MTX-604e */
37 	"debug", "/tmp/nvram", 0, sizeof(Nvrsafe),
38 };
39 
40 static char*
41 readcons(char *prompt, char *def, int raw, char *buf, int nbuf)
42 {
43 	int fdin, fdout, ctl, n, m;
44 	char line[10];
45 
46 	fdin = open("/dev/cons", OREAD);
47 	if(fdin < 0)
48 		fdin = 0;
49 	fdout = open("/dev/cons", OWRITE);
50 	if(fdout < 0)
51 		fdout = 1;
52 	if(def != nil)
53 		fprint(fdout, "%s[%s]: ", prompt, def);
54 	else
55 		fprint(fdout, "%s: ", prompt);
56 	if(raw){
57 		ctl = open("/dev/consctl", OWRITE);
58 		if(ctl >= 0)
59 			write(ctl, "rawon", 5);
60 	} else
61 		ctl = -1;
62 
63 	m = 0;
64 	for(;;){
65 		n = read(fdin, line, 1);
66 		if(n == 0){
67 			close(ctl);
68 			werrstr("readcons: EOF");
69 			return nil;
70 		}
71 		if(n < 0){
72 			close(ctl);
73 			werrstr("can't read cons");
74 			return nil;
75 		}
76 		if(line[0] == 0x7f)
77 			exits(0);
78 		if(n == 0 || line[0] == '\n' || line[0] == '\r'){
79 			if(raw){
80 				write(ctl, "rawoff", 6);
81 				write(fdout, "\n", 1);
82 				close(ctl);
83 			}
84 			buf[m] = '\0';
85 			if(buf[0]=='\0' && def)
86 				strcpy(buf, def);
87 			return buf;
88 		}
89 		if(line[0] == '\b'){
90 			if(m > 0)
91 				m--;
92 		}else if(line[0] == 0x15){	/* ^U: line kill */
93 			m = 0;
94 			if(def != nil)
95 				fprint(fdout, "%s[%s]: ", prompt, def);
96 			else
97 				fprint(fdout, "%s: ", prompt);
98 		}else{
99 			if(m >= nbuf-1){
100 				fprint(fdout, "line too long\n");
101 				m = 0;
102 				if(def != nil)
103 					fprint(fdout, "%s[%s]: ", prompt, def);
104 				else
105 					fprint(fdout, "%s: ", prompt);
106 			}else
107 				buf[m++] = line[0];
108 		}
109 	}
110 	return buf;	/* how does this happen */
111 }
112 
113 
114 /*
115  *  get key info out of nvram.  since there isn't room in the PC's nvram use
116  *  a disk partition there.
117  */
118 int
119 readnvram(Nvrsafe *safep, int flag)
120 {
121 	char buf[1024], in[128], *cputype;
122 	int fd, err, i, safeoff, safelen;
123 	Nvrsafe *safe;
124 
125 	err = 0;
126 	memset(safep, 0, sizeof(*safep));
127 
128 	cputype = getenv("cputype");
129 	if(cputype == nil)
130 		cputype = "mips";
131 	if(strcmp(cputype, "386")==0 || strcmp(cputype, "alpha")==0)
132 		cputype = "pc";
133 
134 	safe = (Nvrsafe*)buf;
135 
136 	fd = -1;
137 	safeoff = -1;
138 	safelen = -1;
139 	for(i=0; i<nelem(nvtab); i++){
140 		if(strcmp(cputype, nvtab[i].cputype) != 0)
141 			continue;
142 		if((fd = open(nvtab[i].file, ORDWR)) < 0)
143 			continue;
144 		safeoff = nvtab[i].off;
145 		safelen = nvtab[i].len;
146 		if(safeoff == -1){
147 			safeoff = finddosfile(fd, "plan9.nvr");
148 			if(safeoff < 0){
149 				close(fd);
150 				fd = -1;
151 				continue;
152 			}
153 		}
154 		break;
155 	}
156 
157 	if(fd < 0
158 	|| seek(fd, safeoff, 0) < 0
159 	|| read(fd, buf, safelen) != safelen){
160 		err = 1;
161 		if(flag&(NVwrite|NVwriteonerr))
162 			fprint(2, "can't read nvram: %r\n");
163 		memset(safep, 0, sizeof(*safep));
164 		safe = safep;
165 	}else{
166 		*safep = *safe;
167 		safe = safep;
168 
169 		err |= check(safe->machkey, DESKEYLEN, safe->machsum, "bad nvram key");
170 //		err |= check(safe->config, CONFIGLEN, safe->configsum, "bad secstore key");
171 		err |= check(safe->authid, ANAMELEN, safe->authidsum, "bad authentication id");
172 		err |= check(safe->authdom, DOMLEN, safe->authdomsum, "bad authentication domain");
173 	}
174 
175 	if((flag&NVwrite) || (err && (flag&NVwriteonerr))){
176 		readcons("authid", nil, 0, safe->authid, sizeof(safe->authid));
177 		readcons("authdom", nil, 0, safe->authdom, sizeof(safe->authdom));
178 		readcons("secstore key", nil, 1, safe->config, sizeof(safe->config));
179 		for(;;){
180 			if(readcons("password", nil, 1, in, sizeof in) == nil)
181 				goto Out;
182 			if(passtokey(safe->machkey, in))
183 				break;
184 		}
185 		safe->machsum = nvcsum(safe->machkey, DESKEYLEN);
186 		safe->configsum = nvcsum(safe->config, CONFIGLEN);
187 		safe->authidsum = nvcsum(safe->authid, sizeof(safe->authid));
188 		safe->authdomsum = nvcsum(safe->authdom, sizeof(safe->authdom));
189 		*(Nvrsafe*)buf = *safe;
190 		if(seek(fd, safeoff, 0) < 0
191 		|| write(fd, buf, safelen) != safelen){
192 			fprint(2, "can't write key to nvram: %r\n");
193 			err = 1;
194 		}else
195 			err = 0;
196 	}
197 Out:
198 	close(fd);
199 	return err ? -1 : 0;
200 }
201 
202 typedef struct Dosboot	Dosboot;
203 struct Dosboot{
204 	uchar	magic[3];	/* really an xx86 JMP instruction */
205 	uchar	version[8];
206 	uchar	sectsize[2];
207 	uchar	clustsize;
208 	uchar	nresrv[2];
209 	uchar	nfats;
210 	uchar	rootsize[2];
211 	uchar	volsize[2];
212 	uchar	mediadesc;
213 	uchar	fatsize[2];
214 	uchar	trksize[2];
215 	uchar	nheads[2];
216 	uchar	nhidden[4];
217 	uchar	bigvolsize[4];
218 	uchar	driveno;
219 	uchar	reserved0;
220 	uchar	bootsig;
221 	uchar	volid[4];
222 	uchar	label[11];
223 	uchar	type[8];
224 };
225 #define	GETSHORT(p) (((p)[1]<<8) | (p)[0])
226 #define	GETLONG(p) ((GETSHORT((p)+2) << 16) | GETSHORT((p)))
227 
228 typedef struct Dosdir	Dosdir;
229 struct Dosdir
230 {
231 	char	name[8];
232 	char	ext[3];
233 	uchar	attr;
234 	uchar	reserved[10];
235 	uchar	time[2];
236 	uchar	date[2];
237 	uchar	start[2];
238 	uchar	length[4];
239 };
240 
241 static char*
242 dosparse(char *from, char *to, int len)
243 {
244 	char c;
245 
246 	memset(to, ' ', len);
247 	if(from == 0)
248 		return 0;
249 	while(len-- > 0){
250 		c = *from++;
251 		if(c == '.')
252 			return from;
253 		if(c == 0)
254 			break;
255 		if(c >= 'a' && c <= 'z')
256 			*to++ = c + 'A' - 'a';
257 		else
258 			*to++ = c;
259 	}
260 	return 0;
261 }
262 
263 /*
264  *  return offset of first file block
265  *
266  *  This is a very simplistic dos file system.  It only
267  *  works on floppies, only looks in the root, and only
268  *  returns a pointer to the first block of a file.
269  *
270  *  This exists for cpu servers that have no hard disk
271  *  or nvram to store the key on.
272  *
273  *  Please don't make this any smarter: it stays resident
274  *  and I'ld prefer not to waste the space on something that
275  *  runs only at boottime -- presotto.
276  */
277 static long
278 finddosfile(int fd, char *file)
279 {
280 	uchar secbuf[512];
281 	char name[8];
282 	char ext[3];
283 	Dosboot	*b;
284 	Dosdir *root, *dp;
285 	int nroot, sectsize, rootoff, rootsects, n;
286 
287 	/* dos'ize file name */
288 	file = dosparse(file, name, 8);
289 	dosparse(file, ext, 3);
290 
291 	/* read boot block, check for sanity */
292 	b = (Dosboot*)secbuf;
293 	if(read(fd, secbuf, sizeof(secbuf)) != sizeof(secbuf))
294 		return -1;
295 	if(b->magic[0] != 0xEB || b->magic[1] != 0x3C || b->magic[2] != 0x90)
296 		return -1;
297 	sectsize = GETSHORT(b->sectsize);
298 	if(sectsize != 512)
299 		return -1;
300 	rootoff = (GETSHORT(b->nresrv) + b->nfats*GETSHORT(b->fatsize)) * sectsize;
301 	if(seek(fd, rootoff, 0) < 0)
302 		return -1;
303 	nroot = GETSHORT(b->rootsize);
304 	rootsects = (nroot*sizeof(Dosdir)+sectsize-1)/sectsize;
305 	if(rootsects <= 0 || rootsects > 64)
306 		return -1;
307 
308 	/*
309 	 *  read root. it is contiguous to make stuff like
310 	 *  this easier
311 	 */
312 	root = malloc(rootsects*sectsize);
313 	if(read(fd, root, rootsects*sectsize) != rootsects*sectsize)
314 		return -1;
315 	n = -1;
316 	for(dp = root; dp < &root[nroot]; dp++)
317 		if(memcmp(name, dp->name, 8) == 0 && memcmp(ext, dp->ext, 3) == 0){
318 			n = GETSHORT(dp->start);
319 			break;
320 		}
321 	free(root);
322 
323 	if(n < 0)
324 		return -1;
325 
326 	/*
327 	 *  dp->start is in cluster units, not sectors.  The first
328 	 *  cluster is cluster 2 which starts immediately after the
329 	 *  root directory
330 	 */
331 	return rootoff + rootsects*sectsize + (n-2)*sectsize*b->clustsize;
332 }
333 
334