xref: /plan9-contrib/sys/src/libauthsrv/readnvram.c (revision 6a0da1e79c4597bb521f10becb7e6db81a85bd80)
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 static int
openrd(char * file)139 openrd(char *file)
140 {
141 	int fd;
142 
143 	if(nvramdebug)
144 		fprint(2, "nvram at %s?...", file);
145 	fd = open(file, ORDWR);
146 	if (fd < 0)
147 		fd = open(file, OREAD);
148 	if(nvramdebug)
149 		fprint(2, "%s\n", fd >= 0? "yes": "no");
150 	return fd;
151 }
152 
153 /* returns with *locp filled in and locp->fd open, if possible */
154 static void
findnvram(Nvrwhere * locp)155 findnvram(Nvrwhere *locp)
156 {
157 	char *nvrlen, *nvroff, *nvrcopy, *db, *v[2];
158 	int fd, i, safeoff, safelen;
159 
160 	if (nvrfile == nil) {
161 		nvrfile = getenv("nvram");
162 		db = getenv("nvramdebug");
163 		nvramdebug = db != nil;
164 		free(db);
165 	}
166 	if (cputype == nil)
167 		cputype = getenv("cputype");
168 	if(cputype == nil)
169 		cputype = strdup("mips");
170 	if(strcmp(cputype, "386")==0 || strcmp(cputype, "amd64")==0 || strcmp(cputype, "alpha")==0) {
171 		free(cputype);
172 		cputype = strdup("pc");
173 	}
174 
175 	fd = -1;
176 	safeoff = -1;
177 	safelen = -1;
178 	if(nvrfile != nil && *nvrfile != '\0'){
179 		/* accept device and device!file */
180 		nvrcopy = strdup(nvrfile);
181 		i = gettokens(nvrcopy, v, nelem(v), "!");
182 		if (i < 1) {
183 			i = 1;
184 			v[0] = "";
185 			v[1] = nil;
186 		}
187 		fd = openrd(v[0]);
188 		safelen = sizeof(Nvrsafe);
189 		if(strstr(v[0], "/9fat") == nil)
190 			safeoff = 0;
191 		nvrlen = getenv("nvrlen");
192 		if(nvrlen != nil)
193 			safelen = atoi(nvrlen);
194 		nvroff = getenv("nvroff");
195 		if(nvroff != nil)
196 			if(strcmp(nvroff, "dos") == 0)
197 				safeoff = -1;
198 			else
199 				safeoff = atoi(nvroff);
200 		if(safeoff < 0 && fd >= 0){
201 			safelen = 512;
202 			safeoff = finddosfile(fd, i == 2? v[1]: "plan9.nvr");
203 			if(safeoff < 0){	/* didn't find plan9.nvr? */
204 				close(fd);
205 				fd = -1;
206 			}
207 		}
208 		free(nvrcopy);
209 		free(nvroff);
210 		free(nvrlen);
211 	}else{
212 		for(i=0; i<nelem(nvtab); i++){
213 			if(strcmp(cputype, nvtab[i].cputype) != 0)
214 				continue;
215 			if((fd = openrd(nvtab[i].file)) < 0)
216 				continue;
217 			safeoff = nvtab[i].off;
218 			safelen = nvtab[i].len;
219 			if(safeoff == -1){
220 				safeoff = finddosfile(fd, "plan9.nvr");
221 				if(safeoff < 0){  /* didn't find plan9.nvr? */
222 					close(fd);
223 					fd = -1;
224 					continue;
225 				}
226 			}
227 			nvrfile = strdup(nvtab[i].file);
228 			break;
229 		}
230 		if(i >= nelem(nvtab))		/* tried them all? */
231 			werrstr("");		/* ignore failed opens */
232 	}
233 	locp->fd = fd;
234 	locp->safelen = safelen;
235 	locp->safeoff = safeoff;
236 }
237 
238 /*
239  *  get key info out of nvram.  since there isn't room in the PC's nvram use
240  *  a disk partition there.
241  */
242 int
readnvram(Nvrsafe * safep,int flag)243 readnvram(Nvrsafe *safep, int flag)
244 {
245 	int err;
246 	char buf[512], in[128];		/* 512 for floppy i/o */
247 	Nvrsafe *safe;
248 	Nvrwhere loc;
249 
250 	err = 0;
251 	safe = (Nvrsafe*)buf;
252 	memset(&loc, 0, sizeof loc);
253 	findnvram(&loc);
254 	if (loc.safelen < 0)
255 		loc.safelen = sizeof *safe;
256 	else if (loc.safelen > sizeof buf)
257 		loc.safelen = sizeof buf;
258 	if (loc.safeoff < 0) {
259 		fprint(2, "readnvram: can't find nvram\n");
260 		if(!(flag&NVwritemem))
261 			memset(safep, 0, sizeof(*safep));
262 		safe = safep;
263 		/*
264 		 * allow user to type the data for authentication,
265 		 * even if there's no nvram to store it in.
266 		 */
267 	}
268 
269 	if(flag&NVwritemem)
270 		safe = safep;
271 	else {
272 		memset(safep, 0, sizeof(*safep));
273 		if(loc.fd >= 0)
274 			werrstr("");
275 		if(loc.fd < 0
276 		|| seek(loc.fd, loc.safeoff, 0) < 0
277 		|| read(loc.fd, buf, loc.safelen) != loc.safelen){
278 			err = 1;
279 			if(flag&(NVwrite|NVwriteonerr))
280 				if(loc.fd < 0 && nvrfile != nil)
281 					fprint(2, "can't open %s: %r\n", nvrfile);
282 				else if(loc.fd < 0){
283 					/* this will have been printed above */
284 					// fprint(2, "can't find nvram: %r\n");
285 				}else if (seek(loc.fd, loc.safeoff, 0) < 0)
286 					fprint(2, "can't seek %s to %d: %r\n",
287 						nvrfile, loc.safeoff);
288 				else
289 					fprint(2, "can't read %d bytes from %s: %r\n",
290 						loc.safelen, nvrfile);
291 			/* start from scratch */
292 			memset(safep, 0, sizeof(*safep));
293 			safe = safep;
294 		}else{
295 			*safep = *safe;	/* overwrite arg with data read */
296 			safe = safep;
297 
298 			/* verify data read */
299 			err |= check(safe->machkey, DESKEYLEN, safe->machsum,
300 						"bad authentication password");
301 //			err |= check(safe->config, CONFIGLEN, safe->configsum,
302 //						"bad secstore password");
303 			err |= check(safe->authid, ANAMELEN, safe->authidsum,
304 						"bad authentication id");
305 			err |= check(safe->authdom, DOMLEN, safe->authdomsum,
306 						"bad authentication domain");
307 			if(err == 0)
308 				if(safe->authid[0]==0 || safe->authdom[0]==0){
309 					fprint(2, "empty nvram authid or authdom\n");
310 					err = 1;
311 				}
312 		}
313 	}
314 
315 	if((flag&(NVwrite|NVwritemem)) || (err && (flag&NVwriteonerr))){
316 		if (!(flag&NVwritemem)) {
317 			readcons("authid", nil, 0, safe->authid,
318 					sizeof safe->authid);
319 			readcons("authdom", nil, 0, safe->authdom,
320 					sizeof safe->authdom);
321 			for(;;){
322 				if(readcons("auth password", nil, 1, in,
323 				    sizeof in) == nil)
324 					goto Out;
325 				if(passtokey(safe->machkey, in))
326 					break;
327 			}
328 			readcons("secstore password", nil, 1, safe->config,
329 					sizeof safe->config);
330 		}
331 
332 		// safe->authsum = nvcsum(safe->authkey, DESKEYLEN);
333 		safe->machsum = nvcsum(safe->machkey, DESKEYLEN);
334 		safe->configsum = nvcsum(safe->config, CONFIGLEN);
335 		safe->authidsum = nvcsum(safe->authid, sizeof safe->authid);
336 		safe->authdomsum = nvcsum(safe->authdom, sizeof safe->authdom);
337 
338 		*(Nvrsafe*)buf = *safe;
339 		if(loc.fd >= 0)
340 			werrstr("");
341 		if(loc.fd < 0
342 		|| seek(loc.fd, loc.safeoff, 0) < 0
343 		|| write(loc.fd, buf, loc.safelen) != loc.safelen){
344 			fprint(2, "can't write key to nvram: %r\n");
345 			err = 1;
346 		}else
347 			err = 0;
348 	}
349 Out:
350 	if (loc.fd >= 0)
351 		close(loc.fd);
352 	return err? -1: 0;
353 }
354 
355 typedef struct Dosboot	Dosboot;
356 struct Dosboot{
357 	uchar	magic[3];	/* really an xx86 JMP instruction */
358 	uchar	version[8];
359 	uchar	sectsize[2];
360 	uchar	clustsize;
361 	uchar	nresrv[2];
362 	uchar	nfats;
363 	uchar	rootsize[2];
364 	uchar	volsize[2];
365 	uchar	mediadesc;
366 	uchar	fatsize[2];
367 	uchar	trksize[2];
368 	uchar	nheads[2];
369 	uchar	nhidden[4];
370 	uchar	bigvolsize[4];
371 	uchar	driveno;
372 	uchar	reserved0;
373 	uchar	bootsig;
374 	uchar	volid[4];
375 	uchar	label[11];
376 	uchar	type[8];
377 };
378 #define	GETSHORT(p) (((p)[1]<<8) | (p)[0])
379 #define	GETLONG(p) ((GETSHORT((p)+2) << 16) | GETSHORT((p)))
380 
381 typedef struct Dosdir	Dosdir;
382 struct Dosdir
383 {
384 	char	name[8];
385 	char	ext[3];
386 	uchar	attr;
387 	uchar	reserved[10];
388 	uchar	time[2];
389 	uchar	date[2];
390 	uchar	start[2];
391 	uchar	length[4];
392 };
393 
394 static char*
dosparse(char * from,char * to,int len)395 dosparse(char *from, char *to, int len)
396 {
397 	char c;
398 
399 	memset(to, ' ', len);
400 	if(from == 0)
401 		return 0;
402 	while(len-- > 0){
403 		c = *from++;
404 		if(c == '.')
405 			return from;
406 		if(c == 0)
407 			break;
408 		if(c >= 'a' && c <= 'z')
409 			*to++ = c + 'A' - 'a';
410 		else
411 			*to++ = c;
412 	}
413 	return 0;
414 }
415 
416 /*
417  *  return offset of first file block
418  *
419  *  This is a very simplistic dos file system.  It only
420  *  works on floppies, only looks in the root, and only
421  *  returns a pointer to the first block of a file.
422  *
423  *  This exists for cpu servers that have no hard disk
424  *  or nvram to store the key on.
425  *
426  *  Please don't make this any smarter: it stays resident
427  *  and I'ld prefer not to waste the space on something that
428  *  runs only at boottime -- presotto.
429  */
430 static long
finddosfile(int fd,char * file)431 finddosfile(int fd, char *file)
432 {
433 	uchar secbuf[512];
434 	char name[8];
435 	char ext[3];
436 	Dosboot	*b;
437 	Dosdir *root, *dp;
438 	int nroot, sectsize, rootoff, rootsects, n;
439 
440 	/* dos'ize file name */
441 	file = dosparse(file, name, 8);
442 	dosparse(file, ext, 3);
443 
444 	/* read boot block, check for sanity */
445 	b = (Dosboot*)secbuf;
446 	if(read(fd, secbuf, sizeof(secbuf)) != sizeof(secbuf))
447 		return -1;
448 	if(b->magic[0] != 0xEB || b->magic[1] != 0x3C || b->magic[2] != 0x90)
449 		return -1;
450 	sectsize = GETSHORT(b->sectsize);
451 	if(sectsize != 512)
452 		return -1;
453 	rootoff = (GETSHORT(b->nresrv) + b->nfats*GETSHORT(b->fatsize)) * sectsize;
454 	if(seek(fd, rootoff, 0) < 0)
455 		return -1;
456 	nroot = GETSHORT(b->rootsize);
457 	rootsects = (nroot*sizeof(Dosdir)+sectsize-1)/sectsize;
458 	if(rootsects <= 0 || rootsects > 64)
459 		return -1;
460 
461 	/*
462 	 *  read root. it is contiguous to make stuff like
463 	 *  this easier
464 	 */
465 	root = malloc(rootsects*sectsize);
466 	if(read(fd, root, rootsects*sectsize) != rootsects*sectsize)
467 		return -1;
468 	n = -1;
469 	for(dp = root; dp < &root[nroot]; dp++)
470 		if(memcmp(name, dp->name, 8) == 0 && memcmp(ext, dp->ext, 3) == 0){
471 			n = GETSHORT(dp->start);
472 			break;
473 		}
474 	free(root);
475 
476 	if(n < 0)
477 		return -1;
478 
479 	/*
480 	 *  dp->start is in cluster units, not sectors.  The first
481 	 *  cluster is cluster 2 which starts immediately after the
482 	 *  root directory
483 	 */
484 	return rootoff + rootsects*sectsize + (n-2)*sectsize*b->clustsize;
485 }
486 
487