xref: /plan9-contrib/sys/src/libauthsrv/readnvram.c (revision 98bee55e8690f268add16b409238fe14795b717c)
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, *nvrcopy, *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 		nvrcopy = strdup(nvrfile);
160 		i = gettokens(nvrcopy, v, nelem(v), "!");
161 		if (i < 1) {
162 			i = 1;
163 			v[0] = "";
164 			v[1] = nil;
165 		}
166 		fd = open(v[0], ORDWR);
167 		if (fd < 0)
168 			fd = open(v[0], OREAD);
169 		safelen = sizeof(Nvrsafe);
170 		if(strstr(v[0], "/9fat") == nil)
171 			safeoff = 0;
172 		nvrlen = getenv("nvrlen");
173 		if(nvrlen != nil)
174 			safelen = atoi(nvrlen);
175 		nvroff = getenv("nvroff");
176 		if(nvroff != nil)
177 			if(strcmp(nvroff, "dos") == 0)
178 				safeoff = -1;
179 			else
180 				safeoff = atoi(nvroff);
181 		if(safeoff < 0 && fd >= 0){
182 			safelen = 512;
183 			safeoff = finddosfile(fd, i == 2? v[1]: "plan9.nvr");
184 			if(safeoff < 0){	/* didn't find plan9.nvr? */
185 				close(fd);
186 				fd = -1;
187 			}
188 		}
189 		free(nvrcopy);
190 		free(nvroff);
191 		free(nvrlen);
192 	}else{
193 		for(i=0; i<nelem(nvtab); i++){
194 			if(strcmp(cputype, nvtab[i].cputype) != 0)
195 				continue;
196 			if((fd = open(nvtab[i].file, ORDWR)) < 0)
197 				continue;
198 			safeoff = nvtab[i].off;
199 			safelen = nvtab[i].len;
200 			if(safeoff == -1){
201 				safeoff = finddosfile(fd, "plan9.nvr");
202 				if(safeoff < 0){  /* didn't find plan9.nvr? */
203 					close(fd);
204 					fd = -1;
205 					continue;
206 				}
207 			}
208 			nvrfile = strdup(nvtab[i].file);
209 			break;
210 		}
211 		if(i >= nelem(nvtab))		/* tried them all? */
212 			werrstr("");		/* ignore failed opens */
213 	}
214 	locp->fd = fd;
215 	locp->safelen = safelen;
216 	locp->safeoff = safeoff;
217 }
218 
219 /*
220  *  get key info out of nvram.  since there isn't room in the PC's nvram use
221  *  a disk partition there.
222  */
223 int
224 readnvram(Nvrsafe *safep, int flag)
225 {
226 	int err;
227 	char buf[512], in[128];		/* 512 for floppy i/o */
228 	Nvrsafe *safe;
229 	Nvrwhere loc;
230 
231 	err = 0;
232 	safe = (Nvrsafe*)buf;
233 	memset(&loc, 0, sizeof loc);
234 	findnvram(&loc);
235 	if (loc.safelen < 0)
236 		loc.safelen = sizeof *safe;
237 	else if (loc.safelen > sizeof buf)
238 		loc.safelen = sizeof buf;
239 	if (loc.safeoff < 0) {
240 		fprint(2, "readnvram: can't find nvram\n");
241 		if(!(flag&NVwritemem))
242 			memset(safep, 0, sizeof(*safep));
243 		safe = safep;
244 		/*
245 		 * allow user to type the data for authentication,
246 		 * even if there's no nvram to store it in.
247 		 */
248 	}
249 
250 	if(flag&NVwritemem)
251 		safe = safep;
252 	else {
253 		memset(safep, 0, sizeof(*safep));
254 		werrstr("");
255 		if(loc.fd < 0
256 		|| seek(loc.fd, loc.safeoff, 0) < 0
257 		|| read(loc.fd, buf, loc.safelen) != loc.safelen){
258 			err = 1;
259 			if(flag&(NVwrite|NVwriteonerr))
260 				if(loc.fd < 0 && nvrfile != nil)
261 					fprint(2, "can't open %s: %r\n", nvrfile);
262 				else if(loc.fd < 0){
263 					/* this will have been printed above */
264 					// fprint(2, "can't find nvram: %r\n");
265 				}else if (seek(loc.fd, loc.safeoff, 0) < 0)
266 					fprint(2, "can't seek %s to %d: %r\n",
267 						nvrfile, loc.safeoff);
268 				else
269 					fprint(2, "can't read %d bytes from %s: %r\n",
270 						loc.safelen, nvrfile);
271 			/* start from scratch */
272 			memset(safep, 0, sizeof(*safep));
273 			safe = safep;
274 		}else{
275 			*safep = *safe;	/* overwrite arg with data read */
276 			safe = safep;
277 
278 			/* verify data read */
279 			err |= check(safe->machkey, DESKEYLEN, safe->machsum,
280 						"bad authentication password");
281 //			err |= check(safe->config, CONFIGLEN, safe->configsum,
282 //						"bad secstore password");
283 			err |= check(safe->authid, ANAMELEN, safe->authidsum,
284 						"bad authentication id");
285 			err |= check(safe->authdom, DOMLEN, safe->authdomsum,
286 						"bad authentication domain");
287 			if(err == 0)
288 				if(safe->authid[0]==0 || safe->authdom[0]==0){
289 					fprint(2, "empty nvram authid or authdom\n");
290 					err = 1;
291 				}
292 		}
293 	}
294 
295 	if((flag&(NVwrite|NVwritemem)) || (err && (flag&NVwriteonerr))){
296 		if (!(flag&NVwritemem)) {
297 			readcons("authid", nil, 0, safe->authid,
298 					sizeof safe->authid);
299 			readcons("authdom", nil, 0, safe->authdom,
300 					sizeof safe->authdom);
301 			for(;;){
302 				if(readcons("auth password", nil, 1, in,
303 				    sizeof in) == nil)
304 					goto Out;
305 				if(passtokey(safe->machkey, in))
306 					break;
307 			}
308 			readcons("secstore password", nil, 1, safe->config,
309 					sizeof safe->config);
310 		}
311 
312 		// safe->authsum = nvcsum(safe->authkey, DESKEYLEN);
313 		safe->machsum = nvcsum(safe->machkey, DESKEYLEN);
314 		safe->configsum = nvcsum(safe->config, CONFIGLEN);
315 		safe->authidsum = nvcsum(safe->authid, sizeof safe->authid);
316 		safe->authdomsum = nvcsum(safe->authdom, sizeof safe->authdom);
317 
318 		*(Nvrsafe*)buf = *safe;
319 		werrstr("");
320 		if(loc.fd < 0
321 		|| seek(loc.fd, loc.safeoff, 0) < 0
322 		|| write(loc.fd, buf, loc.safelen) != loc.safelen){
323 			fprint(2, "can't write key to nvram: %r\n");
324 			err = 1;
325 		}else
326 			err = 0;
327 	}
328 Out:
329 	if (loc.fd >= 0)
330 		close(loc.fd);
331 	return err? -1: 0;
332 }
333 
334 typedef struct Dosboot	Dosboot;
335 struct Dosboot{
336 	uchar	magic[3];	/* really an xx86 JMP instruction */
337 	uchar	version[8];
338 	uchar	sectsize[2];
339 	uchar	clustsize;
340 	uchar	nresrv[2];
341 	uchar	nfats;
342 	uchar	rootsize[2];
343 	uchar	volsize[2];
344 	uchar	mediadesc;
345 	uchar	fatsize[2];
346 	uchar	trksize[2];
347 	uchar	nheads[2];
348 	uchar	nhidden[4];
349 	uchar	bigvolsize[4];
350 	uchar	driveno;
351 	uchar	reserved0;
352 	uchar	bootsig;
353 	uchar	volid[4];
354 	uchar	label[11];
355 	uchar	type[8];
356 };
357 #define	GETSHORT(p) (((p)[1]<<8) | (p)[0])
358 #define	GETLONG(p) ((GETSHORT((p)+2) << 16) | GETSHORT((p)))
359 
360 typedef struct Dosdir	Dosdir;
361 struct Dosdir
362 {
363 	char	name[8];
364 	char	ext[3];
365 	uchar	attr;
366 	uchar	reserved[10];
367 	uchar	time[2];
368 	uchar	date[2];
369 	uchar	start[2];
370 	uchar	length[4];
371 };
372 
373 static char*
374 dosparse(char *from, char *to, int len)
375 {
376 	char c;
377 
378 	memset(to, ' ', len);
379 	if(from == 0)
380 		return 0;
381 	while(len-- > 0){
382 		c = *from++;
383 		if(c == '.')
384 			return from;
385 		if(c == 0)
386 			break;
387 		if(c >= 'a' && c <= 'z')
388 			*to++ = c + 'A' - 'a';
389 		else
390 			*to++ = c;
391 	}
392 	return 0;
393 }
394 
395 /*
396  *  return offset of first file block
397  *
398  *  This is a very simplistic dos file system.  It only
399  *  works on floppies, only looks in the root, and only
400  *  returns a pointer to the first block of a file.
401  *
402  *  This exists for cpu servers that have no hard disk
403  *  or nvram to store the key on.
404  *
405  *  Please don't make this any smarter: it stays resident
406  *  and I'ld prefer not to waste the space on something that
407  *  runs only at boottime -- presotto.
408  */
409 static long
410 finddosfile(int fd, char *file)
411 {
412 	uchar secbuf[512];
413 	char name[8];
414 	char ext[3];
415 	Dosboot	*b;
416 	Dosdir *root, *dp;
417 	int nroot, sectsize, rootoff, rootsects, n;
418 
419 	/* dos'ize file name */
420 	file = dosparse(file, name, 8);
421 	dosparse(file, ext, 3);
422 
423 	/* read boot block, check for sanity */
424 	b = (Dosboot*)secbuf;
425 	if(read(fd, secbuf, sizeof(secbuf)) != sizeof(secbuf))
426 		return -1;
427 	if(b->magic[0] != 0xEB || b->magic[1] != 0x3C || b->magic[2] != 0x90)
428 		return -1;
429 	sectsize = GETSHORT(b->sectsize);
430 	if(sectsize != 512)
431 		return -1;
432 	rootoff = (GETSHORT(b->nresrv) + b->nfats*GETSHORT(b->fatsize)) * sectsize;
433 	if(seek(fd, rootoff, 0) < 0)
434 		return -1;
435 	nroot = GETSHORT(b->rootsize);
436 	rootsects = (nroot*sizeof(Dosdir)+sectsize-1)/sectsize;
437 	if(rootsects <= 0 || rootsects > 64)
438 		return -1;
439 
440 	/*
441 	 *  read root. it is contiguous to make stuff like
442 	 *  this easier
443 	 */
444 	root = malloc(rootsects*sectsize);
445 	if(read(fd, root, rootsects*sectsize) != rootsects*sectsize)
446 		return -1;
447 	n = -1;
448 	for(dp = root; dp < &root[nroot]; dp++)
449 		if(memcmp(name, dp->name, 8) == 0 && memcmp(ext, dp->ext, 3) == 0){
450 			n = GETSHORT(dp->start);
451 			break;
452 		}
453 	free(root);
454 
455 	if(n < 0)
456 		return -1;
457 
458 	/*
459 	 *  dp->start is in cluster units, not sectors.  The first
460 	 *  cluster is cluster 2 which starts immediately after the
461 	 *  root directory
462 	 */
463 	return rootoff + rootsects*sectsize + (n-2)*sectsize*b->clustsize;
464 }
465 
466