xref: /plan9/sys/src/libauthsrv/readnvram.c (revision 0aa8dc3ce45e27c8119541cf306abb402a5895d8)
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", "#f/fd0disk", -1, 512,	/* 512: #f requires whole sector reads */
43 	"pc", "#f/fd1disk", -1, 512,
44 	"mips", "#r/nvram", 1024+900, sizeof(Nvrsafe),
45 	"power", "#F/flash/flash0", 0x440000, sizeof(Nvrsafe),
46 	"power", "#r/nvram", 4352, sizeof(Nvrsafe),	/* OK for MTX-604e */
47 	"power", "/nvram", 0, sizeof(Nvrsafe),	/* OK for Ucu */
48 	"debug", "/tmp/nvram", 0, sizeof(Nvrsafe),
49 };
50 
51 static char*
52 readcons(char *prompt, char *def, int raw, char *buf, int nbuf)
53 {
54 	int fdin, fdout, ctl, n, m;
55 	char line[10];
56 
57 	fdin = open("/dev/cons", OREAD);
58 	if(fdin < 0)
59 		fdin = 0;
60 	fdout = open("/dev/cons", OWRITE);
61 	if(fdout < 0)
62 		fdout = 1;
63 	if(def != nil)
64 		fprint(fdout, "%s[%s]: ", prompt, def);
65 	else
66 		fprint(fdout, "%s: ", prompt);
67 	if(raw){
68 		ctl = open("/dev/consctl", OWRITE);
69 		if(ctl >= 0)
70 			write(ctl, "rawon", 5);
71 	} else
72 		ctl = -1;
73 
74 	m = 0;
75 	for(;;){
76 		n = read(fdin, line, 1);
77 		if(n == 0){
78 			close(ctl);
79 			werrstr("readcons: EOF");
80 			return nil;
81 		}
82 		if(n < 0){
83 			close(ctl);
84 			werrstr("can't read cons");
85 			return nil;
86 		}
87 		if(line[0] == 0x7f)
88 			exits(0);
89 		if(n == 0 || line[0] == '\n' || line[0] == '\r'){
90 			if(raw){
91 				write(ctl, "rawoff", 6);
92 				write(fdout, "\n", 1);
93 				close(ctl);
94 			}
95 			buf[m] = '\0';
96 			if(buf[0]=='\0' && def)
97 				strcpy(buf, def);
98 			return buf;
99 		}
100 		if(line[0] == '\b'){
101 			if(m > 0)
102 				m--;
103 		}else if(line[0] == 0x15){	/* ^U: line kill */
104 			m = 0;
105 			if(def != nil)
106 				fprint(fdout, "%s[%s]: ", prompt, def);
107 			else
108 				fprint(fdout, "%s: ", prompt);
109 		}else{
110 			if(m >= nbuf-1){
111 				fprint(fdout, "line too long\n");
112 				m = 0;
113 				if(def != nil)
114 					fprint(fdout, "%s[%s]: ", prompt, def);
115 				else
116 					fprint(fdout, "%s: ", prompt);
117 			}else
118 				buf[m++] = line[0];
119 		}
120 	}
121 }
122 
123 
124 /*
125  *  get key info out of nvram.  since there isn't room in the PC's nvram use
126  *  a disk partition there.
127  */
128 int
129 readnvram(Nvrsafe *safep, int flag)
130 {
131 	char buf[1024], in[128], *cputype, *nvrfile, *nvrlen, *nvroff, *v[2];
132 	int fd, err, i, safeoff, safelen;
133 	Nvrsafe *safe;
134 
135 	err = 0;
136 	memset(safep, 0, sizeof(*safep));
137 
138 	nvrfile = getenv("nvram");
139 	cputype = getenv("cputype");
140 	if(cputype == nil)
141 		cputype = "mips";
142 	if(strcmp(cputype, "386")==0 || strcmp(cputype, "alpha")==0)
143 		cputype = "pc";
144 
145 	safe = (Nvrsafe*)buf;
146 
147 	fd = -1;
148 	safeoff = -1;
149 	safelen = -1;
150 	if(nvrfile != nil){
151 		/* accept device and device!file */
152 		i = gettokens(nvrfile, v, nelem(v), "!");
153 		fd = open(v[0], ORDWR);
154 		safelen = sizeof(Nvrsafe);
155 		if(strstr(v[0], "/9fat") == nil)
156 			safeoff = 0;
157 		nvrlen = getenv("nvrlen");
158 		if(nvrlen != nil)
159 			safelen = atoi(nvrlen);
160 		nvroff = getenv("nvroff");
161 		if(nvroff != nil){
162 			if(strcmp(nvroff, "dos") == 0)
163 				safeoff = -1;
164 			else
165 				safeoff = atoi(nvroff);
166 		}
167 		if(safeoff < 0 && fd >= 0){
168 			safelen = 512;
169 			safeoff = finddosfile(fd, i == 2 ? v[1] : "plan9.nvr");
170 			if(safeoff < 0){
171 				close(fd);
172 				fd = -1;
173 			}
174 		}
175 		free(nvrfile);
176 		if(nvrlen != nil)
177 			free(nvrlen);
178 		if(nvroff != nil)
179 			free(nvroff);
180 	}else{
181 		for(i=0; i<nelem(nvtab); i++){
182 			if(strcmp(cputype, nvtab[i].cputype) != 0)
183 				continue;
184 			if((fd = open(nvtab[i].file, ORDWR)) < 0)
185 				continue;
186 			safeoff = nvtab[i].off;
187 			safelen = nvtab[i].len;
188 			if(safeoff == -1){
189 				safeoff = finddosfile(fd, "plan9.nvr");
190 				if(safeoff < 0){
191 					close(fd);
192 					fd = -1;
193 					continue;
194 				}
195 			}
196 			break;
197 		}
198 	}
199 
200 	if(fd < 0
201 	|| seek(fd, safeoff, 0) < 0
202 	|| read(fd, buf, safelen) != safelen){
203 		err = 1;
204 		if(flag&(NVwrite|NVwriteonerr))
205 			fprint(2, "can't read nvram: %r\n");
206 		memset(safep, 0, sizeof(*safep));
207 		safe = safep;
208 	}else{
209 		*safep = *safe;
210 		safe = safep;
211 
212 		err |= check(safe->machkey, DESKEYLEN, safe->machsum, "bad nvram key");
213 //		err |= check(safe->config, CONFIGLEN, safe->configsum, "bad secstore key");
214 		err |= check(safe->authid, ANAMELEN, safe->authidsum, "bad authentication id");
215 		err |= check(safe->authdom, DOMLEN, safe->authdomsum, "bad authentication domain");
216 
217 		if(err == 0)
218 		if(safe->authid[0]==0 || safe->authdom[0]==0){
219 			fprint(2, "empty nvram authid or authdom\n");
220 			err = 1;
221 		}
222 	}
223 
224 	if((flag&NVwrite) || (err && (flag&NVwriteonerr))){
225 		readcons("authid", nil, 0, safe->authid, sizeof(safe->authid));
226 		readcons("authdom", nil, 0, safe->authdom, sizeof(safe->authdom));
227 		readcons("secstore key", nil, 1, safe->config, sizeof(safe->config));
228 		for(;;){
229 			if(readcons("password", nil, 1, in, sizeof in) == nil)
230 				goto Out;
231 			if(passtokey(safe->machkey, in))
232 				break;
233 		}
234 		safe->machsum = nvcsum(safe->machkey, DESKEYLEN);
235 		safe->configsum = nvcsum(safe->config, CONFIGLEN);
236 		safe->authidsum = nvcsum(safe->authid, sizeof(safe->authid));
237 		safe->authdomsum = nvcsum(safe->authdom, sizeof(safe->authdom));
238 		*(Nvrsafe*)buf = *safe;
239 		if(seek(fd, safeoff, 0) < 0
240 		|| write(fd, buf, safelen) != safelen){
241 			fprint(2, "can't write key to nvram: %r\n");
242 			err = 1;
243 		}else
244 			err = 0;
245 	}
246 Out:
247 	close(fd);
248 	return err ? -1 : 0;
249 }
250 
251 typedef struct Dosboot	Dosboot;
252 struct Dosboot{
253 	uchar	magic[3];	/* really an xx86 JMP instruction */
254 	uchar	version[8];
255 	uchar	sectsize[2];
256 	uchar	clustsize;
257 	uchar	nresrv[2];
258 	uchar	nfats;
259 	uchar	rootsize[2];
260 	uchar	volsize[2];
261 	uchar	mediadesc;
262 	uchar	fatsize[2];
263 	uchar	trksize[2];
264 	uchar	nheads[2];
265 	uchar	nhidden[4];
266 	uchar	bigvolsize[4];
267 	uchar	driveno;
268 	uchar	reserved0;
269 	uchar	bootsig;
270 	uchar	volid[4];
271 	uchar	label[11];
272 	uchar	type[8];
273 };
274 #define	GETSHORT(p) (((p)[1]<<8) | (p)[0])
275 #define	GETLONG(p) ((GETSHORT((p)+2) << 16) | GETSHORT((p)))
276 
277 typedef struct Dosdir	Dosdir;
278 struct Dosdir
279 {
280 	char	name[8];
281 	char	ext[3];
282 	uchar	attr;
283 	uchar	reserved[10];
284 	uchar	time[2];
285 	uchar	date[2];
286 	uchar	start[2];
287 	uchar	length[4];
288 };
289 
290 static char*
291 dosparse(char *from, char *to, int len)
292 {
293 	char c;
294 
295 	memset(to, ' ', len);
296 	if(from == 0)
297 		return 0;
298 	while(len-- > 0){
299 		c = *from++;
300 		if(c == '.')
301 			return from;
302 		if(c == 0)
303 			break;
304 		if(c >= 'a' && c <= 'z')
305 			*to++ = c + 'A' - 'a';
306 		else
307 			*to++ = c;
308 	}
309 	return 0;
310 }
311 
312 /*
313  *  return offset of first file block
314  *
315  *  This is a very simplistic dos file system.  It only
316  *  works on floppies, only looks in the root, and only
317  *  returns a pointer to the first block of a file.
318  *
319  *  This exists for cpu servers that have no hard disk
320  *  or nvram to store the key on.
321  *
322  *  Please don't make this any smarter: it stays resident
323  *  and I'ld prefer not to waste the space on something that
324  *  runs only at boottime -- presotto.
325  */
326 static long
327 finddosfile(int fd, char *file)
328 {
329 	uchar secbuf[512];
330 	char name[8];
331 	char ext[3];
332 	Dosboot	*b;
333 	Dosdir *root, *dp;
334 	int nroot, sectsize, rootoff, rootsects, n;
335 
336 	/* dos'ize file name */
337 	file = dosparse(file, name, 8);
338 	dosparse(file, ext, 3);
339 
340 	/* read boot block, check for sanity */
341 	b = (Dosboot*)secbuf;
342 	if(read(fd, secbuf, sizeof(secbuf)) != sizeof(secbuf))
343 		return -1;
344 	if(b->magic[0] != 0xEB || b->magic[1] != 0x3C || b->magic[2] != 0x90)
345 		return -1;
346 	sectsize = GETSHORT(b->sectsize);
347 	if(sectsize != 512)
348 		return -1;
349 	rootoff = (GETSHORT(b->nresrv) + b->nfats*GETSHORT(b->fatsize)) * sectsize;
350 	if(seek(fd, rootoff, 0) < 0)
351 		return -1;
352 	nroot = GETSHORT(b->rootsize);
353 	rootsects = (nroot*sizeof(Dosdir)+sectsize-1)/sectsize;
354 	if(rootsects <= 0 || rootsects > 64)
355 		return -1;
356 
357 	/*
358 	 *  read root. it is contiguous to make stuff like
359 	 *  this easier
360 	 */
361 	root = malloc(rootsects*sectsize);
362 	if(read(fd, root, rootsects*sectsize) != rootsects*sectsize)
363 		return -1;
364 	n = -1;
365 	for(dp = root; dp < &root[nroot]; dp++)
366 		if(memcmp(name, dp->name, 8) == 0 && memcmp(ext, dp->ext, 3) == 0){
367 			n = GETSHORT(dp->start);
368 			break;
369 		}
370 	free(root);
371 
372 	if(n < 0)
373 		return -1;
374 
375 	/*
376 	 *  dp->start is in cluster units, not sectors.  The first
377 	 *  cluster is cluster 2 which starts immediately after the
378 	 *  root directory
379 	 */
380 	return rootoff + rootsects*sectsize + (n-2)*sectsize*b->clustsize;
381 }
382 
383