xref: /plan9/sys/src/libauthsrv/readnvram.c (revision 2ce711d43c5e84d642d7e64a5c08ce5f40799bc1)
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/sdC1/nvram", 0, sizeof(Nvrsafe),
31 	"pc", "#S/sdC1/9fat", -1, sizeof(Nvrsafe),
32 	"pc", "#S/sdD0/nvram", 0, sizeof(Nvrsafe),
33 	"pc", "#S/sdD0/9fat", -1, sizeof(Nvrsafe),
34 	"pc", "#S/sdE0/nvram", 0, sizeof(Nvrsafe),
35 	"pc", "#S/sdE0/9fat", -1, sizeof(Nvrsafe),
36 	"pc", "#S/sdF0/nvram", 0, sizeof(Nvrsafe),
37 	"pc", "#S/sdF0/9fat", -1, sizeof(Nvrsafe),
38 	"pc", "#S/sd00/nvram", 0, sizeof(Nvrsafe),
39 	"pc", "#S/sd00/9fat", -1, sizeof(Nvrsafe),
40 	"pc", "#S/sd01/nvram", 0, sizeof(Nvrsafe),
41 	"pc", "#S/sd01/9fat", -1, sizeof(Nvrsafe),
42 	"pc", "#S/sd10/nvram", 0, sizeof(Nvrsafe),
43 	"pc", "#S/sd10/9fat", -1, sizeof(Nvrsafe),
44 	"pc", "#f/fd0disk", -1, 512,	/* 512: #f requires whole sector reads */
45 	"pc", "#f/fd1disk", -1, 512,
46 	"mips", "#r/nvram", 1024+900, sizeof(Nvrsafe),
47 	"power", "#F/flash/flash0", 0x440000, sizeof(Nvrsafe),
48 	"power", "#F/flash/flash", 0x440000, sizeof(Nvrsafe),
49 	"power", "#r/nvram", 4352, sizeof(Nvrsafe),	/* OK for MTX-604e */
50 	"power", "/nvram", 0, sizeof(Nvrsafe),	/* OK for Ucu */
51 	"arm", "#F/flash/flash0", 0x100000, sizeof(Nvrsafe),
52 	"arm", "#F/flash/flash", 0x100000, sizeof(Nvrsafe),
53 	"debug", "/tmp/nvram", 0, sizeof(Nvrsafe),
54 };
55 
56 static char*
57 readcons(char *prompt, char *def, int raw, char *buf, int nbuf)
58 {
59 	int fdin, fdout, ctl, n, m;
60 	char line[10];
61 
62 	fdin = open("/dev/cons", OREAD);
63 	if(fdin < 0)
64 		fdin = 0;
65 	fdout = open("/dev/cons", OWRITE);
66 	if(fdout < 0)
67 		fdout = 1;
68 	if(def != nil)
69 		fprint(fdout, "%s[%s]: ", prompt, def);
70 	else
71 		fprint(fdout, "%s: ", prompt);
72 	if(raw){
73 		ctl = open("/dev/consctl", OWRITE);
74 		if(ctl >= 0)
75 			write(ctl, "rawon", 5);
76 	} else
77 		ctl = -1;
78 
79 	m = 0;
80 	for(;;){
81 		n = read(fdin, line, 1);
82 		if(n == 0){
83 			close(ctl);
84 			werrstr("readcons: EOF");
85 			return nil;
86 		}
87 		if(n < 0){
88 			close(ctl);
89 			werrstr("can't read cons");
90 			return nil;
91 		}
92 		if(line[0] == 0x7f)
93 			exits(0);
94 		if(n == 0 || line[0] == '\n' || line[0] == '\r'){
95 			if(raw){
96 				write(ctl, "rawoff", 6);
97 				write(fdout, "\n", 1);
98 				close(ctl);
99 			}
100 			buf[m] = '\0';
101 			if(buf[0]=='\0' && def)
102 				strcpy(buf, def);
103 			return buf;
104 		}
105 		if(line[0] == '\b'){
106 			if(m > 0)
107 				m--;
108 		}else if(line[0] == 0x15){	/* ^U: line kill */
109 			m = 0;
110 			if(def != nil)
111 				fprint(fdout, "%s[%s]: ", prompt, def);
112 			else
113 				fprint(fdout, "%s: ", prompt);
114 		}else{
115 			if(m >= nbuf-1){
116 				fprint(fdout, "line too long\n");
117 				m = 0;
118 				if(def != nil)
119 					fprint(fdout, "%s[%s]: ", prompt, def);
120 				else
121 					fprint(fdout, "%s: ", prompt);
122 			}else
123 				buf[m++] = line[0];
124 		}
125 	}
126 }
127 
128 typedef struct {
129 	int	fd;
130 	int	safeoff;
131 	int	safelen;
132 } Nvrwhere;
133 
134 static char *nvrfile = nil, *cputype = nil;
135 
136 /* returns with *locp filled in and locp->fd open, if possible */
137 static void
138 findnvram(Nvrwhere *locp)
139 {
140 	char *nvrlen, *nvroff, *v[2];
141 	int fd, i, safeoff, safelen;
142 
143 	if (nvrfile == nil)
144 		nvrfile = getenv("nvram");
145 	if (cputype == nil)
146 		cputype = getenv("cputype");
147 	if(cputype == nil)
148 		cputype = strdup("mips");
149 	if(strcmp(cputype, "386")==0 || strcmp(cputype, "alpha")==0) {
150 		free(cputype);
151 		cputype = strdup("pc");
152 	}
153 
154 	fd = -1;
155 	safeoff = -1;
156 	safelen = -1;
157 	if(nvrfile != nil && *nvrfile != '\0'){
158 		/* accept device and device!file */
159 		i = gettokens(nvrfile, v, nelem(v), "!");
160 		if (i < 1) {
161 			i = 1;
162 			v[0] = "";
163 			v[1] = nil;
164 		}
165 		fd = open(v[0], ORDWR);
166 		if (fd < 0)
167 			fd = open(v[0], OREAD);
168 		safelen = sizeof(Nvrsafe);
169 		if(strstr(v[0], "/9fat") == nil)
170 			safeoff = 0;
171 		nvrlen = getenv("nvrlen");
172 		if(nvrlen != nil)
173 			safelen = atoi(nvrlen);
174 		nvroff = getenv("nvroff");
175 		if(nvroff != nil)
176 			if(strcmp(nvroff, "dos") == 0)
177 				safeoff = -1;
178 			else
179 				safeoff = atoi(nvroff);
180 		if(safeoff < 0 && fd >= 0){
181 			safelen = 512;
182 			safeoff = finddosfile(fd, i == 2? v[1]: "plan9.nvr");
183 			if(safeoff < 0){	/* didn't find plan9.nvr? */
184 				close(fd);
185 				fd = -1;
186 			}
187 		}
188 		free(nvroff);
189 		free(nvrlen);
190 	}else
191 		for(i=0; i<nelem(nvtab); i++){
192 			if(strcmp(cputype, nvtab[i].cputype) != 0)
193 				continue;
194 			if((fd = open(nvtab[i].file, ORDWR)) < 0)
195 				continue;
196 			safeoff = nvtab[i].off;
197 			safelen = nvtab[i].len;
198 			if(safeoff == -1){
199 				safeoff = finddosfile(fd, "plan9.nvr");
200 				if(safeoff < 0){  /* didn't find plan9.nvr? */
201 					close(fd);
202 					fd = -1;
203 					continue;
204 				}
205 			}
206 			break;
207 		}
208 	locp->fd = fd;
209 	locp->safelen = safelen;
210 	locp->safeoff = safeoff;
211 }
212 
213 /*
214  *  get key info out of nvram.  since there isn't room in the PC's nvram use
215  *  a disk partition there.
216  */
217 int
218 readnvram(Nvrsafe *safep, int flag)
219 {
220 	int err;
221 	char buf[512], in[128];		/* 512 for floppy i/o */
222 	Nvrsafe *safe;
223 	Nvrwhere loc;
224 
225 	err = 0;
226 	safe = (Nvrsafe*)buf;
227 	memset(&loc, 0, sizeof loc);
228 	findnvram(&loc);
229 	if (loc.safelen < 0)
230 		loc.safelen = sizeof *safe;
231 	else if (loc.safelen > sizeof buf)
232 		loc.safelen = sizeof buf;
233 	if (loc.safeoff < 0) {
234 		fprint(2, "readnvram: couldn't find nvram\n");
235 		if(!(flag&NVwritemem))
236 			memset(safep, 0, sizeof(*safep));
237 		safe = safep;
238 		/*
239 		 * allow user to type the data for authentication,
240 		 * even if there's no nvram to store it in.
241 		 */
242 	}
243 
244 	if(flag&NVwritemem)
245 		safe = safep;
246 	else {
247 		memset(safep, 0, sizeof(*safep));
248 		if(loc.fd < 0
249 		|| seek(loc.fd, loc.safeoff, 0) < 0
250 		|| read(loc.fd, buf, loc.safelen) != loc.safelen){
251 			err = 1;
252 			if(flag&(NVwrite|NVwriteonerr))
253 				if(loc.fd < 0)
254 					fprint(2, "can't open %s: %r\n", nvrfile);
255 				else if (seek(loc.fd, loc.safeoff, 0) < 0)
256 					fprint(2, "can't seek %s to %d: %r\n",
257 						nvrfile, loc.safeoff);
258 				else
259 					fprint(2, "can't read %d bytes from %s: %r\n",
260 						loc.safelen, nvrfile);
261 			/* start from scratch */
262 			memset(safep, 0, sizeof(*safep));
263 			safe = safep;
264 		}else{
265 			*safep = *safe;	/* overwrite arg with data read */
266 			safe = safep;
267 
268 			/* verify data read */
269 			err |= check(safe->machkey, DESKEYLEN, safe->machsum,
270 						"bad nvram key");
271 //			err |= check(safe->config, CONFIGLEN, safe->configsum,
272 //						"bad secstore key");
273 			err |= check(safe->authid, ANAMELEN, safe->authidsum,
274 						"bad authentication id");
275 			err |= check(safe->authdom, DOMLEN, safe->authdomsum,
276 						"bad authentication domain");
277 			if(err == 0)
278 				if(safe->authid[0]==0 || safe->authdom[0]==0){
279 					fprint(2, "empty nvram authid or authdom\n");
280 					err = 1;
281 				}
282 		}
283 	}
284 
285 	if((flag&(NVwrite|NVwritemem)) || (err && (flag&NVwriteonerr))){
286 		if (!(flag&NVwritemem)) {
287 			readcons("authid", nil, 0, safe->authid,
288 					sizeof safe->authid);
289 			readcons("authdom", nil, 0, safe->authdom,
290 					sizeof safe->authdom);
291 			readcons("secstore key", nil, 1, safe->config,
292 					sizeof safe->config);
293 			for(;;){
294 				if(readcons("password", nil, 1, in, sizeof in)
295 				    == nil)
296 					goto Out;
297 				if(passtokey(safe->machkey, in))
298 					break;
299 			}
300 		}
301 
302 		// safe->authsum = nvcsum(safe->authkey, DESKEYLEN);
303 		safe->machsum = nvcsum(safe->machkey, DESKEYLEN);
304 		safe->configsum = nvcsum(safe->config, CONFIGLEN);
305 		safe->authidsum = nvcsum(safe->authid, sizeof safe->authid);
306 		safe->authdomsum = nvcsum(safe->authdom, sizeof safe->authdom);
307 
308 		*(Nvrsafe*)buf = *safe;
309 		if(loc.fd < 0
310 		|| seek(loc.fd, loc.safeoff, 0) < 0
311 		|| write(loc.fd, buf, loc.safelen) != loc.safelen){
312 			fprint(2, "can't write key to nvram: %r\n");
313 			err = 1;
314 		}else
315 			err = 0;
316 	}
317 Out:
318 	if (loc.fd >= 0)
319 		close(loc.fd);
320 	return err? -1: 0;
321 }
322 
323 typedef struct Dosboot	Dosboot;
324 struct Dosboot{
325 	uchar	magic[3];	/* really an xx86 JMP instruction */
326 	uchar	version[8];
327 	uchar	sectsize[2];
328 	uchar	clustsize;
329 	uchar	nresrv[2];
330 	uchar	nfats;
331 	uchar	rootsize[2];
332 	uchar	volsize[2];
333 	uchar	mediadesc;
334 	uchar	fatsize[2];
335 	uchar	trksize[2];
336 	uchar	nheads[2];
337 	uchar	nhidden[4];
338 	uchar	bigvolsize[4];
339 	uchar	driveno;
340 	uchar	reserved0;
341 	uchar	bootsig;
342 	uchar	volid[4];
343 	uchar	label[11];
344 	uchar	type[8];
345 };
346 #define	GETSHORT(p) (((p)[1]<<8) | (p)[0])
347 #define	GETLONG(p) ((GETSHORT((p)+2) << 16) | GETSHORT((p)))
348 
349 typedef struct Dosdir	Dosdir;
350 struct Dosdir
351 {
352 	char	name[8];
353 	char	ext[3];
354 	uchar	attr;
355 	uchar	reserved[10];
356 	uchar	time[2];
357 	uchar	date[2];
358 	uchar	start[2];
359 	uchar	length[4];
360 };
361 
362 static char*
363 dosparse(char *from, char *to, int len)
364 {
365 	char c;
366 
367 	memset(to, ' ', len);
368 	if(from == 0)
369 		return 0;
370 	while(len-- > 0){
371 		c = *from++;
372 		if(c == '.')
373 			return from;
374 		if(c == 0)
375 			break;
376 		if(c >= 'a' && c <= 'z')
377 			*to++ = c + 'A' - 'a';
378 		else
379 			*to++ = c;
380 	}
381 	return 0;
382 }
383 
384 /*
385  *  return offset of first file block
386  *
387  *  This is a very simplistic dos file system.  It only
388  *  works on floppies, only looks in the root, and only
389  *  returns a pointer to the first block of a file.
390  *
391  *  This exists for cpu servers that have no hard disk
392  *  or nvram to store the key on.
393  *
394  *  Please don't make this any smarter: it stays resident
395  *  and I'ld prefer not to waste the space on something that
396  *  runs only at boottime -- presotto.
397  */
398 static long
399 finddosfile(int fd, char *file)
400 {
401 	uchar secbuf[512];
402 	char name[8];
403 	char ext[3];
404 	Dosboot	*b;
405 	Dosdir *root, *dp;
406 	int nroot, sectsize, rootoff, rootsects, n;
407 
408 	/* dos'ize file name */
409 	file = dosparse(file, name, 8);
410 	dosparse(file, ext, 3);
411 
412 	/* read boot block, check for sanity */
413 	b = (Dosboot*)secbuf;
414 	if(read(fd, secbuf, sizeof(secbuf)) != sizeof(secbuf))
415 		return -1;
416 	if(b->magic[0] != 0xEB || b->magic[1] != 0x3C || b->magic[2] != 0x90)
417 		return -1;
418 	sectsize = GETSHORT(b->sectsize);
419 	if(sectsize != 512)
420 		return -1;
421 	rootoff = (GETSHORT(b->nresrv) + b->nfats*GETSHORT(b->fatsize)) * sectsize;
422 	if(seek(fd, rootoff, 0) < 0)
423 		return -1;
424 	nroot = GETSHORT(b->rootsize);
425 	rootsects = (nroot*sizeof(Dosdir)+sectsize-1)/sectsize;
426 	if(rootsects <= 0 || rootsects > 64)
427 		return -1;
428 
429 	/*
430 	 *  read root. it is contiguous to make stuff like
431 	 *  this easier
432 	 */
433 	root = malloc(rootsects*sectsize);
434 	if(read(fd, root, rootsects*sectsize) != rootsects*sectsize)
435 		return -1;
436 	n = -1;
437 	for(dp = root; dp < &root[nroot]; dp++)
438 		if(memcmp(name, dp->name, 8) == 0 && memcmp(ext, dp->ext, 3) == 0){
439 			n = GETSHORT(dp->start);
440 			break;
441 		}
442 	free(root);
443 
444 	if(n < 0)
445 		return -1;
446 
447 	/*
448 	 *  dp->start is in cluster units, not sectors.  The first
449 	 *  cluster is cluster 2 which starts immediately after the
450 	 *  root directory
451 	 */
452 	return rootoff + rootsects*sectsize + (n-2)*sectsize*b->clustsize;
453 }
454 
455