xref: /plan9/sys/src/libauthsrv/readnvram.c (revision 23173ec17955c609738f37acefe0c6e72a169a75)
1 #include <u.h>
2 #include <libc.h>
3 #include <authsrv.h>
4 
5 static long	finddosfile(int, char*);
6 
7 static int nvramdebug;
8 
9 static int
check(void * x,int len,uchar sum,char * msg)10 check(void *x, int len, uchar sum, char *msg)
11 {
12 	if(nvcsum(x, len) == sum)
13 		return 0;
14 	memset(x, 0, len);
15 	fprint(2, "%s\n", msg);
16 	return 1;
17 }
18 
19 /*
20  *  get key info out of nvram.  since there isn't room in the PC's nvram use
21  *  a disk partition there.
22  */
23 static struct {
24 	char *cputype;
25 	char *file;
26 	int off;
27 	int len;
28 } nvtab[] = {
29 	"sparc", "#r/nvram", 1024+850, sizeof(Nvrsafe),
30 	"pc", "#S/sdC0/nvram", 0, sizeof(Nvrsafe),
31 	"pc", "#S/sdC0/9fat", -1, sizeof(Nvrsafe),
32 	"pc", "#S/sdC1/nvram", 0, sizeof(Nvrsafe),
33 	"pc", "#S/sdC1/9fat", -1, sizeof(Nvrsafe),
34 	"pc", "#S/sdD0/nvram", 0, sizeof(Nvrsafe),
35 	"pc", "#S/sdD0/9fat", -1, sizeof(Nvrsafe),
36 	"pc", "#S/sdE0/nvram", 0, sizeof(Nvrsafe),
37 	"pc", "#S/sdE0/9fat", -1, sizeof(Nvrsafe),
38 	"pc", "#S/sdF0/nvram", 0, sizeof(Nvrsafe),
39 	"pc", "#S/sdF0/9fat", -1, sizeof(Nvrsafe),
40 	"pc", "#S/sd00/nvram", 0, sizeof(Nvrsafe),
41 	"pc", "#S/sd00/9fat", -1, sizeof(Nvrsafe),
42 	"pc", "#S/sd01/nvram", 0, sizeof(Nvrsafe),
43 	"pc", "#S/sd01/9fat", -1, sizeof(Nvrsafe),
44 	"pc", "#S/sd10/nvram", 0, sizeof(Nvrsafe),
45 	"pc", "#S/sd10/9fat", -1, sizeof(Nvrsafe),
46 	"pc", "#f/fd0disk", -1, 512,	/* 512: #f requires whole sector reads */
47 	"pc", "#f/fd1disk", -1, 512,
48 	"mips", "#r/nvram", 1024+900, sizeof(Nvrsafe),
49 	"power", "#F/flash/flash0", 0x440000, sizeof(Nvrsafe),
50 	"power", "#F/flash/flash", 0x440000, sizeof(Nvrsafe),
51 	"power", "#r/nvram", 4352, sizeof(Nvrsafe),	/* OK for MTX-604e */
52 	"power", "/nvram", 0, sizeof(Nvrsafe),	/* OK for Ucu */
53 	"arm", "#F/flash/flash0", 0x100000, sizeof(Nvrsafe),
54 	"arm", "#F/flash/flash", 0x100000, sizeof(Nvrsafe),
55 	"debug", "/tmp/nvram", 0, sizeof(Nvrsafe),
56 };
57 
58 static char*
readcons(char * prompt,char * def,int raw,char * buf,int nbuf)59 readcons(char *prompt, char *def, int raw, char *buf, int nbuf)
60 {
61 	int fdin, fdout, ctl, n, m;
62 	char line[10];
63 
64 	fdin = open("/dev/cons", OREAD);
65 	if(fdin < 0)
66 		fdin = 0;
67 	fdout = open("/dev/cons", OWRITE);
68 	if(fdout < 0)
69 		fdout = 1;
70 	if(def != nil)
71 		fprint(fdout, "%s[%s]: ", prompt, def);
72 	else
73 		fprint(fdout, "%s: ", prompt);
74 	if(raw){
75 		ctl = open("/dev/consctl", OWRITE);
76 		if(ctl >= 0)
77 			write(ctl, "rawon", 5);
78 	} else
79 		ctl = -1;
80 
81 	m = 0;
82 	for(;;){
83 		n = read(fdin, line, 1);
84 		if(n == 0){
85 			close(ctl);
86 			werrstr("readcons: EOF");
87 			return nil;
88 		}
89 		if(n < 0){
90 			close(ctl);
91 			werrstr("can't read cons");
92 			return nil;
93 		}
94 		if(line[0] == 0x7f)
95 			exits(0);
96 		if(n == 0 || line[0] == '\n' || line[0] == '\r'){
97 			if(raw){
98 				write(ctl, "rawoff", 6);
99 				write(fdout, "\n", 1);
100 				close(ctl);
101 			}
102 			buf[m] = '\0';
103 			if(buf[0]=='\0' && def)
104 				strcpy(buf, def);
105 			return buf;
106 		}
107 		if(line[0] == '\b'){
108 			if(m > 0)
109 				m--;
110 		}else if(line[0] == 0x15){	/* ^U: line kill */
111 			m = 0;
112 			if(def != nil)
113 				fprint(fdout, "%s[%s]: ", prompt, def);
114 			else
115 				fprint(fdout, "%s: ", prompt);
116 		}else{
117 			if(m >= nbuf-1){
118 				fprint(fdout, "line too long\n");
119 				m = 0;
120 				if(def != nil)
121 					fprint(fdout, "%s[%s]: ", prompt, def);
122 				else
123 					fprint(fdout, "%s: ", prompt);
124 			}else
125 				buf[m++] = line[0];
126 		}
127 	}
128 }
129 
130 typedef struct {
131 	int	fd;
132 	int	safeoff;
133 	int	safelen;
134 } Nvrwhere;
135 
136 static char *nvrfile = nil, *cputype = nil;
137 
138 /* returns with *locp filled in and locp->fd open, if possible */
139 static void
findnvram(Nvrwhere * locp)140 findnvram(Nvrwhere *locp)
141 {
142 	char *nvrlen, *nvroff, *nvrcopy, *db, *v[2];
143 	int fd, i, safeoff, safelen;
144 
145 	if (nvrfile == nil) {
146 		nvrfile = getenv("nvram");
147 		db = getenv("nvramdebug");
148 		nvramdebug = db != nil;
149 		free(db);
150 	}
151 	if (cputype == nil)
152 		cputype = getenv("cputype");
153 	if(cputype == nil)
154 		cputype = strdup("mips");
155 	if(strcmp(cputype, "386")==0 || strcmp(cputype, "alpha")==0) {
156 		free(cputype);
157 		cputype = strdup("pc");
158 	}
159 
160 	fd = -1;
161 	safeoff = -1;
162 	safelen = -1;
163 	if(nvrfile != nil && *nvrfile != '\0'){
164 		/* accept device and device!file */
165 		nvrcopy = strdup(nvrfile);
166 		i = gettokens(nvrcopy, v, nelem(v), "!");
167 		if (i < 1) {
168 			i = 1;
169 			v[0] = "";
170 			v[1] = nil;
171 		}
172 		if(nvramdebug)
173 			fprint(2, "nvram at %s?...", v[0]);
174 		fd = open(v[0], ORDWR);
175 		if (fd < 0)
176 			fd = open(v[0], OREAD);
177 		safelen = sizeof(Nvrsafe);
178 		if(strstr(v[0], "/9fat") == nil)
179 			safeoff = 0;
180 		nvrlen = getenv("nvrlen");
181 		if(nvrlen != nil)
182 			safelen = atoi(nvrlen);
183 		nvroff = getenv("nvroff");
184 		if(nvroff != nil)
185 			if(strcmp(nvroff, "dos") == 0)
186 				safeoff = -1;
187 			else
188 				safeoff = atoi(nvroff);
189 		if(safeoff < 0 && fd >= 0){
190 			safelen = 512;
191 			safeoff = finddosfile(fd, i == 2? v[1]: "plan9.nvr");
192 			if(safeoff < 0){	/* didn't find plan9.nvr? */
193 				close(fd);
194 				fd = -1;
195 			}
196 		}
197 		free(nvrcopy);
198 		free(nvroff);
199 		free(nvrlen);
200 	}else{
201 		for(i=0; i<nelem(nvtab); i++){
202 			if(strcmp(cputype, nvtab[i].cputype) != 0)
203 				continue;
204 			if(nvramdebug)
205 				fprint(2, "nvram at %s?...", nvtab[i].file);
206 			if((fd = open(nvtab[i].file, ORDWR)) < 0 &&
207 			   (fd = open(nvtab[i].file, OREAD)) < 0)
208 				continue;
209 			safeoff = nvtab[i].off;
210 			safelen = nvtab[i].len;
211 			if(safeoff == -1){
212 				safeoff = finddosfile(fd, "plan9.nvr");
213 				if(safeoff < 0){  /* didn't find plan9.nvr? */
214 					close(fd);
215 					fd = -1;
216 					continue;
217 				}
218 			}
219 			nvrfile = strdup(nvtab[i].file);
220 			break;
221 		}
222 		if(i >= nelem(nvtab))		/* tried them all? */
223 			werrstr("");		/* ignore failed opens */
224 	}
225 	locp->fd = fd;
226 	locp->safelen = safelen;
227 	locp->safeoff = safeoff;
228 }
229 
230 /*
231  *  get key info out of nvram.  since there isn't room in the PC's nvram use
232  *  a disk partition there.
233  */
234 int
readnvram(Nvrsafe * safep,int flag)235 readnvram(Nvrsafe *safep, int flag)
236 {
237 	int err;
238 	char buf[512], in[128];		/* 512 for floppy i/o */
239 	Nvrsafe *safe;
240 	Nvrwhere loc;
241 
242 	err = 0;
243 	safe = (Nvrsafe*)buf;
244 	memset(&loc, 0, sizeof loc);
245 	findnvram(&loc);
246 	if (loc.safelen < 0)
247 		loc.safelen = sizeof *safe;
248 	else if (loc.safelen > sizeof buf)
249 		loc.safelen = sizeof buf;
250 	if (loc.safeoff < 0) {
251 		fprint(2, "readnvram: can't find nvram\n");
252 		if(!(flag&NVwritemem))
253 			memset(safep, 0, sizeof(*safep));
254 		safe = safep;
255 		/*
256 		 * allow user to type the data for authentication,
257 		 * even if there's no nvram to store it in.
258 		 */
259 	}
260 
261 	if(flag&NVwritemem)
262 		safe = safep;
263 	else {
264 		memset(safep, 0, sizeof(*safep));
265 		if(loc.fd >= 0)
266 			werrstr("");
267 		if(loc.fd < 0
268 		|| seek(loc.fd, loc.safeoff, 0) < 0
269 		|| read(loc.fd, buf, loc.safelen) != loc.safelen){
270 			err = 1;
271 			if(flag&(NVwrite|NVwriteonerr))
272 				if(loc.fd < 0 && nvrfile != nil)
273 					fprint(2, "can't open %s: %r\n", nvrfile);
274 				else if(loc.fd < 0){
275 					/* this will have been printed above */
276 					// fprint(2, "can't find nvram: %r\n");
277 				}else if (seek(loc.fd, loc.safeoff, 0) < 0)
278 					fprint(2, "can't seek %s to %d: %r\n",
279 						nvrfile, loc.safeoff);
280 				else
281 					fprint(2, "can't read %d bytes from %s: %r\n",
282 						loc.safelen, nvrfile);
283 			/* start from scratch */
284 			memset(safep, 0, sizeof(*safep));
285 			safe = safep;
286 		}else{
287 			*safep = *safe;	/* overwrite arg with data read */
288 			safe = safep;
289 
290 			/* verify data read */
291 			err |= check(safe->machkey, DESKEYLEN, safe->machsum,
292 						"bad authentication password");
293 //			err |= check(safe->config, CONFIGLEN, safe->configsum,
294 //						"bad secstore password");
295 			err |= check(safe->authid, ANAMELEN, safe->authidsum,
296 						"bad authentication id");
297 			err |= check(safe->authdom, DOMLEN, safe->authdomsum,
298 						"bad authentication domain");
299 			if(err == 0)
300 				if(safe->authid[0]==0 || safe->authdom[0]==0){
301 					fprint(2, "empty nvram authid or authdom\n");
302 					err = 1;
303 				}
304 		}
305 	}
306 
307 	if((flag&(NVwrite|NVwritemem)) || (err && (flag&NVwriteonerr))){
308 		if (!(flag&NVwritemem)) {
309 			readcons("authid", nil, 0, safe->authid,
310 					sizeof safe->authid);
311 			readcons("authdom", nil, 0, safe->authdom,
312 					sizeof safe->authdom);
313 			for(;;){
314 				if(readcons("auth password", nil, 1, in,
315 				    sizeof in) == nil)
316 					goto Out;
317 				if(passtokey(safe->machkey, in))
318 					break;
319 			}
320 			readcons("secstore password", nil, 1, safe->config,
321 					sizeof safe->config);
322 		}
323 
324 		// safe->authsum = nvcsum(safe->authkey, DESKEYLEN);
325 		safe->machsum = nvcsum(safe->machkey, DESKEYLEN);
326 		safe->configsum = nvcsum(safe->config, CONFIGLEN);
327 		safe->authidsum = nvcsum(safe->authid, sizeof safe->authid);
328 		safe->authdomsum = nvcsum(safe->authdom, sizeof safe->authdom);
329 
330 		*(Nvrsafe*)buf = *safe;
331 		if(loc.fd >= 0)
332 			werrstr("");
333 		if(loc.fd < 0
334 		|| seek(loc.fd, loc.safeoff, 0) < 0
335 		|| write(loc.fd, buf, loc.safelen) != loc.safelen){
336 			fprint(2, "can't write key to nvram: %r\n");
337 			err = 1;
338 		}else
339 			err = 0;
340 	}
341 Out:
342 	if (loc.fd >= 0)
343 		close(loc.fd);
344 	return err? -1: 0;
345 }
346 
347 typedef struct Dosboot	Dosboot;
348 struct Dosboot{
349 	uchar	magic[3];	/* really an xx86 JMP instruction */
350 	uchar	version[8];
351 	uchar	sectsize[2];
352 	uchar	clustsize;
353 	uchar	nresrv[2];
354 	uchar	nfats;
355 	uchar	rootsize[2];
356 	uchar	volsize[2];
357 	uchar	mediadesc;
358 	uchar	fatsize[2];
359 	uchar	trksize[2];
360 	uchar	nheads[2];
361 	uchar	nhidden[4];
362 	uchar	bigvolsize[4];
363 	uchar	driveno;
364 	uchar	reserved0;
365 	uchar	bootsig;
366 	uchar	volid[4];
367 	uchar	label[11];
368 	uchar	type[8];
369 };
370 #define	GETSHORT(p) (((p)[1]<<8) | (p)[0])
371 #define	GETLONG(p) ((GETSHORT((p)+2) << 16) | GETSHORT((p)))
372 
373 typedef struct Dosdir	Dosdir;
374 struct Dosdir
375 {
376 	char	name[8];
377 	char	ext[3];
378 	uchar	attr;
379 	uchar	reserved[10];
380 	uchar	time[2];
381 	uchar	date[2];
382 	uchar	start[2];
383 	uchar	length[4];
384 };
385 
386 static char*
dosparse(char * from,char * to,int len)387 dosparse(char *from, char *to, int len)
388 {
389 	char c;
390 
391 	memset(to, ' ', len);
392 	if(from == 0)
393 		return 0;
394 	while(len-- > 0){
395 		c = *from++;
396 		if(c == '.')
397 			return from;
398 		if(c == 0)
399 			break;
400 		if(c >= 'a' && c <= 'z')
401 			*to++ = c + 'A' - 'a';
402 		else
403 			*to++ = c;
404 	}
405 	return 0;
406 }
407 
408 /*
409  *  return offset of first file block
410  *
411  *  This is a very simplistic dos file system.  It only
412  *  works on floppies, only looks in the root, and only
413  *  returns a pointer to the first block of a file.
414  *
415  *  This exists for cpu servers that have no hard disk
416  *  or nvram to store the key on.
417  *
418  *  Please don't make this any smarter: it stays resident
419  *  and I'ld prefer not to waste the space on something that
420  *  runs only at boottime -- presotto.
421  */
422 static long
finddosfile(int fd,char * file)423 finddosfile(int fd, char *file)
424 {
425 	uchar secbuf[512];
426 	char name[8];
427 	char ext[3];
428 	Dosboot	*b;
429 	Dosdir *root, *dp;
430 	int nroot, sectsize, rootoff, rootsects, n;
431 
432 	/* dos'ize file name */
433 	file = dosparse(file, name, 8);
434 	dosparse(file, ext, 3);
435 
436 	/* read boot block, check for sanity */
437 	b = (Dosboot*)secbuf;
438 	if(read(fd, secbuf, sizeof(secbuf)) != sizeof(secbuf))
439 		return -1;
440 	if(b->magic[0] != 0xEB || b->magic[1] != 0x3C || b->magic[2] != 0x90)
441 		return -1;
442 	sectsize = GETSHORT(b->sectsize);
443 	if(sectsize != 512)
444 		return -1;
445 	rootoff = (GETSHORT(b->nresrv) + b->nfats*GETSHORT(b->fatsize)) * sectsize;
446 	if(seek(fd, rootoff, 0) < 0)
447 		return -1;
448 	nroot = GETSHORT(b->rootsize);
449 	rootsects = (nroot*sizeof(Dosdir)+sectsize-1)/sectsize;
450 	if(rootsects <= 0 || rootsects > 64)
451 		return -1;
452 
453 	/*
454 	 *  read root. it is contiguous to make stuff like
455 	 *  this easier
456 	 */
457 	root = malloc(rootsects*sectsize);
458 	if(read(fd, root, rootsects*sectsize) != rootsects*sectsize)
459 		return -1;
460 	n = -1;
461 	for(dp = root; dp < &root[nroot]; dp++)
462 		if(memcmp(name, dp->name, 8) == 0 && memcmp(ext, dp->ext, 3) == 0){
463 			n = GETSHORT(dp->start);
464 			break;
465 		}
466 	free(root);
467 
468 	if(n < 0)
469 		return -1;
470 
471 	/*
472 	 *  dp->start is in cluster units, not sectors.  The first
473 	 *  cluster is cluster 2 which starts immediately after the
474 	 *  root directory
475 	 */
476 	return rootoff + rootsects*sectsize + (n-2)*sectsize*b->clustsize;
477 }
478 
479