xref: /plan9/sys/src/libauthsrv/readnvram.c (revision 60014d6756a98ad10929607ca84a1b7488a16cfc)
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", "#r/nvram", 4352, sizeof(Nvrsafe),	/* OK for MTX-604e */
49 	"power", "/nvram", 0, sizeof(Nvrsafe),	/* OK for Ucu */
50 	"arm", "#F/flash/flash0", 0x100000, sizeof(Nvrsafe),
51 	"debug", "/tmp/nvram", 0, sizeof(Nvrsafe),
52 };
53 
54 static char*
55 readcons(char *prompt, char *def, int raw, char *buf, int nbuf)
56 {
57 	int fdin, fdout, ctl, n, m;
58 	char line[10];
59 
60 	fdin = open("/dev/cons", OREAD);
61 	if(fdin < 0)
62 		fdin = 0;
63 	fdout = open("/dev/cons", OWRITE);
64 	if(fdout < 0)
65 		fdout = 1;
66 	if(def != nil)
67 		fprint(fdout, "%s[%s]: ", prompt, def);
68 	else
69 		fprint(fdout, "%s: ", prompt);
70 	if(raw){
71 		ctl = open("/dev/consctl", OWRITE);
72 		if(ctl >= 0)
73 			write(ctl, "rawon", 5);
74 	} else
75 		ctl = -1;
76 
77 	m = 0;
78 	for(;;){
79 		n = read(fdin, line, 1);
80 		if(n == 0){
81 			close(ctl);
82 			werrstr("readcons: EOF");
83 			return nil;
84 		}
85 		if(n < 0){
86 			close(ctl);
87 			werrstr("can't read cons");
88 			return nil;
89 		}
90 		if(line[0] == 0x7f)
91 			exits(0);
92 		if(n == 0 || line[0] == '\n' || line[0] == '\r'){
93 			if(raw){
94 				write(ctl, "rawoff", 6);
95 				write(fdout, "\n", 1);
96 				close(ctl);
97 			}
98 			buf[m] = '\0';
99 			if(buf[0]=='\0' && def)
100 				strcpy(buf, def);
101 			return buf;
102 		}
103 		if(line[0] == '\b'){
104 			if(m > 0)
105 				m--;
106 		}else if(line[0] == 0x15){	/* ^U: line kill */
107 			m = 0;
108 			if(def != nil)
109 				fprint(fdout, "%s[%s]: ", prompt, def);
110 			else
111 				fprint(fdout, "%s: ", prompt);
112 		}else{
113 			if(m >= nbuf-1){
114 				fprint(fdout, "line too long\n");
115 				m = 0;
116 				if(def != nil)
117 					fprint(fdout, "%s[%s]: ", prompt, def);
118 				else
119 					fprint(fdout, "%s: ", prompt);
120 			}else
121 				buf[m++] = line[0];
122 		}
123 	}
124 }
125 
126 typedef struct {
127 	int	fd;
128 	int	safeoff;
129 	int	safelen;
130 } Nvrwhere;
131 
132 /* returns with *locp filled in and locp->fd open, if possible */
133 static void
134 findnvram(Nvrwhere *locp)
135 {
136 	char *cputype, *nvrfile, *nvrlen, *nvroff, *v[2];
137 	int fd, i, safeoff, safelen;
138 
139 	nvrfile = getenv("nvram");
140 	cputype = getenv("cputype");
141 	if(cputype == nil)
142 		cputype = strdup("mips");
143 	if(strcmp(cputype, "386")==0 || strcmp(cputype, "alpha")==0) {
144 		free(cputype);
145 		cputype = strdup("pc");
146 	}
147 
148 	fd = -1;
149 	safeoff = -1;
150 	safelen = -1;
151 	if(nvrfile != nil && *nvrfile != '\0'){
152 		/* accept device and device!file */
153 		i = gettokens(nvrfile, v, nelem(v), "!");
154 		if (i < 1) {
155 			i = 1;
156 			v[0] = "";
157 			v[1] = nil;
158 		}
159 		fd = open(v[0], ORDWR);
160 		if (fd < 0)
161 			fd = open(v[0], OREAD);
162 		safelen = sizeof(Nvrsafe);
163 		if(strstr(v[0], "/9fat") == nil)
164 			safeoff = 0;
165 		nvrlen = getenv("nvrlen");
166 		if(nvrlen != nil)
167 			safelen = atoi(nvrlen);
168 		nvroff = getenv("nvroff");
169 		if(nvroff != nil)
170 			if(strcmp(nvroff, "dos") == 0)
171 				safeoff = -1;
172 			else
173 				safeoff = atoi(nvroff);
174 		if(safeoff < 0 && fd >= 0){
175 			safelen = 512;
176 			safeoff = finddosfile(fd, i == 2? v[1]: "plan9.nvr");
177 			if(safeoff < 0){	/* didn't find plan9.nvr? */
178 				close(fd);
179 				fd = -1;
180 			}
181 		}
182 		free(nvroff);
183 		free(nvrlen);
184 	}else
185 		for(i=0; i<nelem(nvtab); i++){
186 			if(strcmp(cputype, nvtab[i].cputype) != 0)
187 				continue;
188 			if((fd = open(nvtab[i].file, ORDWR)) < 0)
189 				continue;
190 			safeoff = nvtab[i].off;
191 			safelen = nvtab[i].len;
192 			if(safeoff == -1){
193 				safeoff = finddosfile(fd, "plan9.nvr");
194 				if(safeoff < 0){  /* didn't find plan9.nvr? */
195 					close(fd);
196 					fd = -1;
197 					continue;
198 				}
199 			}
200 			break;
201 		}
202 	free(nvrfile);
203 	free(cputype);
204 	locp->fd = fd;
205 	locp->safelen = safelen;
206 	locp->safeoff = safeoff;
207 }
208 
209 /*
210  *  get key info out of nvram.  since there isn't room in the PC's nvram use
211  *  a disk partition there.
212  */
213 int
214 readnvram(Nvrsafe *safep, int flag)
215 {
216 	int err;
217 	char buf[512], in[128];		/* 512 for floppy i/o */
218 	Nvrsafe *safe;
219 	Nvrwhere loc;
220 
221 	err = 0;
222 	safe = (Nvrsafe*)buf;
223 	memset(&loc, 0, sizeof loc);
224 	findnvram(&loc);
225 	if (loc.safelen < 0)
226 		loc.safelen = sizeof *safe;
227 	else if (loc.safelen > sizeof buf)
228 		loc.safelen = sizeof buf;
229 	if (loc.safeoff < 0) {
230 		fprint(2, "readnvram: couldn't find nvram\n");
231 		if(!(flag&NVwritemem))
232 			memset(safep, 0, sizeof(*safep));
233 		safe = safep;
234 		/*
235 		 * allow user to type the data for authentication,
236 		 * even if there's no nvram to store it in.
237 		 */
238 	}
239 
240 	if(flag&NVwritemem)
241 		safe = safep;
242 	else {
243 		memset(safep, 0, sizeof(*safep));
244 		if(loc.fd < 0
245 		|| seek(loc.fd, loc.safeoff, 0) < 0
246 		|| read(loc.fd, buf, loc.safelen) != loc.safelen){
247 			err = 1;
248 			if(flag&(NVwrite|NVwriteonerr))
249 				fprint(2, "can't read nvram: %r\n");
250 			/* start from scratch */
251 			memset(safep, 0, sizeof(*safep));
252 			safe = safep;
253 		}else{
254 			*safep = *safe;	/* overwrite arg with data read */
255 			safe = safep;
256 
257 			/* verify data read */
258 			err |= check(safe->machkey, DESKEYLEN, safe->machsum,
259 						"bad nvram key");
260 //			err |= check(safe->config, CONFIGLEN, safe->configsum,
261 //						"bad secstore key");
262 			err |= check(safe->authid, ANAMELEN, safe->authidsum,
263 						"bad authentication id");
264 			err |= check(safe->authdom, DOMLEN, safe->authdomsum,
265 						"bad authentication domain");
266 			if(err == 0)
267 				if(safe->authid[0]==0 || safe->authdom[0]==0){
268 					fprint(2, "empty nvram authid or authdom\n");
269 					err = 1;
270 				}
271 		}
272 	}
273 
274 	if((flag&(NVwrite|NVwritemem)) || (err && (flag&NVwriteonerr))){
275 		if (!(flag&NVwritemem)) {
276 			readcons("authid", nil, 0, safe->authid,
277 					sizeof safe->authid);
278 			readcons("authdom", nil, 0, safe->authdom,
279 					sizeof safe->authdom);
280 			readcons("secstore key", nil, 1, safe->config,
281 					sizeof safe->config);
282 			for(;;){
283 				if(readcons("password", nil, 1, in, sizeof in)
284 				    == nil)
285 					goto Out;
286 				if(passtokey(safe->machkey, in))
287 					break;
288 			}
289 		}
290 
291 		// safe->authsum = nvcsum(safe->authkey, DESKEYLEN);
292 		safe->machsum = nvcsum(safe->machkey, DESKEYLEN);
293 		safe->configsum = nvcsum(safe->config, CONFIGLEN);
294 		safe->authidsum = nvcsum(safe->authid, sizeof safe->authid);
295 		safe->authdomsum = nvcsum(safe->authdom, sizeof safe->authdom);
296 
297 		*(Nvrsafe*)buf = *safe;
298 		if(loc.fd < 0
299 		|| seek(loc.fd, loc.safeoff, 0) < 0
300 		|| write(loc.fd, buf, loc.safelen) != loc.safelen){
301 			fprint(2, "can't write key to nvram: %r\n");
302 			err = 1;
303 		}else
304 			err = 0;
305 	}
306 Out:
307 	if (loc.fd >= 0)
308 		close(loc.fd);
309 	return err? -1: 0;
310 }
311 
312 typedef struct Dosboot	Dosboot;
313 struct Dosboot{
314 	uchar	magic[3];	/* really an xx86 JMP instruction */
315 	uchar	version[8];
316 	uchar	sectsize[2];
317 	uchar	clustsize;
318 	uchar	nresrv[2];
319 	uchar	nfats;
320 	uchar	rootsize[2];
321 	uchar	volsize[2];
322 	uchar	mediadesc;
323 	uchar	fatsize[2];
324 	uchar	trksize[2];
325 	uchar	nheads[2];
326 	uchar	nhidden[4];
327 	uchar	bigvolsize[4];
328 	uchar	driveno;
329 	uchar	reserved0;
330 	uchar	bootsig;
331 	uchar	volid[4];
332 	uchar	label[11];
333 	uchar	type[8];
334 };
335 #define	GETSHORT(p) (((p)[1]<<8) | (p)[0])
336 #define	GETLONG(p) ((GETSHORT((p)+2) << 16) | GETSHORT((p)))
337 
338 typedef struct Dosdir	Dosdir;
339 struct Dosdir
340 {
341 	char	name[8];
342 	char	ext[3];
343 	uchar	attr;
344 	uchar	reserved[10];
345 	uchar	time[2];
346 	uchar	date[2];
347 	uchar	start[2];
348 	uchar	length[4];
349 };
350 
351 static char*
352 dosparse(char *from, char *to, int len)
353 {
354 	char c;
355 
356 	memset(to, ' ', len);
357 	if(from == 0)
358 		return 0;
359 	while(len-- > 0){
360 		c = *from++;
361 		if(c == '.')
362 			return from;
363 		if(c == 0)
364 			break;
365 		if(c >= 'a' && c <= 'z')
366 			*to++ = c + 'A' - 'a';
367 		else
368 			*to++ = c;
369 	}
370 	return 0;
371 }
372 
373 /*
374  *  return offset of first file block
375  *
376  *  This is a very simplistic dos file system.  It only
377  *  works on floppies, only looks in the root, and only
378  *  returns a pointer to the first block of a file.
379  *
380  *  This exists for cpu servers that have no hard disk
381  *  or nvram to store the key on.
382  *
383  *  Please don't make this any smarter: it stays resident
384  *  and I'ld prefer not to waste the space on something that
385  *  runs only at boottime -- presotto.
386  */
387 static long
388 finddosfile(int fd, char *file)
389 {
390 	uchar secbuf[512];
391 	char name[8];
392 	char ext[3];
393 	Dosboot	*b;
394 	Dosdir *root, *dp;
395 	int nroot, sectsize, rootoff, rootsects, n;
396 
397 	/* dos'ize file name */
398 	file = dosparse(file, name, 8);
399 	dosparse(file, ext, 3);
400 
401 	/* read boot block, check for sanity */
402 	b = (Dosboot*)secbuf;
403 	if(read(fd, secbuf, sizeof(secbuf)) != sizeof(secbuf))
404 		return -1;
405 	if(b->magic[0] != 0xEB || b->magic[1] != 0x3C || b->magic[2] != 0x90)
406 		return -1;
407 	sectsize = GETSHORT(b->sectsize);
408 	if(sectsize != 512)
409 		return -1;
410 	rootoff = (GETSHORT(b->nresrv) + b->nfats*GETSHORT(b->fatsize)) * sectsize;
411 	if(seek(fd, rootoff, 0) < 0)
412 		return -1;
413 	nroot = GETSHORT(b->rootsize);
414 	rootsects = (nroot*sizeof(Dosdir)+sectsize-1)/sectsize;
415 	if(rootsects <= 0 || rootsects > 64)
416 		return -1;
417 
418 	/*
419 	 *  read root. it is contiguous to make stuff like
420 	 *  this easier
421 	 */
422 	root = malloc(rootsects*sectsize);
423 	if(read(fd, root, rootsects*sectsize) != rootsects*sectsize)
424 		return -1;
425 	n = -1;
426 	for(dp = root; dp < &root[nroot]; dp++)
427 		if(memcmp(name, dp->name, 8) == 0 && memcmp(ext, dp->ext, 3) == 0){
428 			n = GETSHORT(dp->start);
429 			break;
430 		}
431 	free(root);
432 
433 	if(n < 0)
434 		return -1;
435 
436 	/*
437 	 *  dp->start is in cluster units, not sectors.  The first
438 	 *  cluster is cluster 2 which starts immediately after the
439 	 *  root directory
440 	 */
441 	return rootoff + rootsects*sectsize + (n-2)*sectsize*b->clustsize;
442 }
443 
444