ref: c3ba64f6935322f09b6de5c2285544fd471c605d
dir: /sys/src/libauthsrv/readnvram.c/
#include <u.h>
#include <libc.h>
#include <authsrv.h>
static long finddosfile(int, char*);
static int
check(void *x, int len, uchar sum, char *msg)
{
if(nvcsum(x, len) == sum)
return 0;
memset(x, 0, len);
fprint(2, "%s\n", msg);
return 1;
}
/*
* get key info out of nvram. since there isn't room in the PC's nvram use
* a disk partition there.
*/
static struct {
char *cputype;
char *file;
int off;
int len;
} nvtab[] = {
"sparc", "#r/nvram", 1024+850, sizeof(Nvrsafe),
"pc", "#S/sdC0/nvram", 0, sizeof(Nvrsafe),
"pc", "#S/sdC0/9fat", -1, sizeof(Nvrsafe),
"pc", "#S/sdC1/nvram", 0, sizeof(Nvrsafe),
"pc", "#S/sdC1/9fat", -1, sizeof(Nvrsafe),
"pc", "#S/sdD0/nvram", 0, sizeof(Nvrsafe),
"pc", "#S/sdD0/9fat", -1, sizeof(Nvrsafe),
"pc", "#S/sdE0/nvram", 0, sizeof(Nvrsafe),
"pc", "#S/sdE0/9fat", -1, sizeof(Nvrsafe),
"pc", "#S/sdF0/nvram", 0, sizeof(Nvrsafe),
"pc", "#S/sdF0/9fat", -1, sizeof(Nvrsafe),
"pc", "#S/sd00/nvram", 0, sizeof(Nvrsafe),
"pc", "#S/sd00/9fat", -1, sizeof(Nvrsafe),
"pc", "#S/sd01/nvram", 0, sizeof(Nvrsafe),
"pc", "#S/sd01/9fat", -1, sizeof(Nvrsafe),
"pc", "#S/sd10/nvram", 0, sizeof(Nvrsafe),
"pc", "#S/sd10/9fat", -1, sizeof(Nvrsafe),
"pc", "#f/fd0disk", -1, 512, /* 512: #f requires whole sector reads */
"pc", "#f/fd1disk", -1, 512,
"mips", "#r/nvram", 1024+900, sizeof(Nvrsafe),
"power", "#F/flash/flash0", 0x440000, sizeof(Nvrsafe),
"power", "#F/flash/flash", 0x440000, sizeof(Nvrsafe),
"power", "#r/nvram", 4352, sizeof(Nvrsafe), /* OK for MTX-604e */
"power", "/nvram", 0, sizeof(Nvrsafe), /* OK for Ucu */
"arm", "#F/flash/flash0", 0x100000, sizeof(Nvrsafe),
"arm", "#F/flash/flash", 0x100000, sizeof(Nvrsafe),
"debug", "/tmp/nvram", 0, sizeof(Nvrsafe),
};
typedef struct {
int fd;
int safelen;
vlong safeoff;
} Nvrwhere;
static char *nvrfile = nil, *cputype = nil;
/* returns with *locp filled in and locp->fd open, if possible */
static void
findnvram(Nvrwhere *locp)
{
char *nvrlen, *nvroff, *v[2];
int fd, i, safelen;
vlong safeoff;
if (nvrfile == nil)
nvrfile = getenv("nvram");
if (cputype == nil)
cputype = getenv("cputype");
if(cputype == nil)
cputype = strdup("mips");
if(strcmp(cputype, "386")==0 || strcmp(cputype, "amd64")==0 || strcmp(cputype, "alpha")==0) {
free(cputype);
cputype = strdup("pc");
}
fd = -1;
safeoff = -1;
safelen = -1;
if(nvrfile != nil && *nvrfile != '\0'){
/* accept device and device!file */
i = gettokens(nvrfile, v, nelem(v), "!");
if (i < 1) {
i = 1;
v[0] = "";
v[1] = nil;
}
fd = open(v[0], ORDWR|OCEXEC);
if (fd < 0)
fd = open(v[0], OREAD|OCEXEC);
safelen = sizeof(Nvrsafe);
if(strstr(v[0], "/9fat") == nil)
safeoff = 0;
nvrlen = getenv("nvrlen");
if(nvrlen != nil)
safelen = strtol(nvrlen, 0, 0);
nvroff = getenv("nvroff");
if(nvroff != nil)
if(strcmp(nvroff, "dos") == 0)
safeoff = -1;
else
safeoff = strtoll(nvroff, 0, 0);
if(safeoff < 0 && fd >= 0){
safelen = 512;
safeoff = finddosfile(fd, i == 2? v[1]: "plan9.nvr");
if(safeoff < 0){ /* didn't find plan9.nvr? */
close(fd);
fd = -1;
}
}
free(nvroff);
free(nvrlen);
}else
for(i=0; i<nelem(nvtab); i++){
if(strcmp(cputype, nvtab[i].cputype) != 0)
continue;
if((fd = open(nvtab[i].file, ORDWR|OCEXEC)) < 0)
continue;
safeoff = nvtab[i].off;
safelen = nvtab[i].len;
if(safeoff == -1){
safeoff = finddosfile(fd, "plan9.nvr");
if(safeoff < 0){ /* didn't find plan9.nvr? */
close(fd);
fd = -1;
continue;
}
}
break;
}
locp->fd = fd;
locp->safelen = safelen;
locp->safeoff = safeoff;
}
static int
ask(char *prompt, char *buf, int len, int raw)
{
char *s;
int n;
memset(buf, 0, len);
for(;;){
if((s = readcons(prompt, nil, raw)) == nil)
return -1;
if((n = strlen(s)) >= len)
fprint(2, "%s longer than %d characters; try again\n", prompt, len-1);
else {
memmove(buf, s, n);
memset(s, 0, n);
free(s);
return 0;
}
memset(s, 0, n);
free(s);
}
}
/*
* get key info out of nvram. since there isn't room in the PC's nvram use
* a disk partition there.
*/
int
readnvram(Nvrsafe *safep, int flag)
{
int err;
char buf[512]; /* 512 for floppy i/o */
Nvrsafe *safe;
Nvrwhere loc;
err = 0;
safe = (Nvrsafe*)buf;
memset(&loc, 0, sizeof loc);
findnvram(&loc);
if (loc.safelen < 0)
loc.safelen = sizeof *safe;
else if (loc.safelen > sizeof buf)
loc.safelen = sizeof buf;
if (loc.safeoff < 0) {
fprint(2, "readnvram: couldn't find nvram\n");
if(!(flag&NVwritemem))
memset(safep, 0, sizeof(*safep));
safe = safep;
/*
* allow user to type the data for authentication,
* even if there's no nvram to store it in.
*/
}
if(flag&NVwritemem)
safe = safep;
else {
memset(safep, 0, sizeof(*safep));
if(loc.fd < 0
|| seek(loc.fd, loc.safeoff, 0) < 0
|| read(loc.fd, buf, loc.safelen) != loc.safelen){
err = 1;
if(flag&(NVwrite|NVwriteonerr))
if(loc.fd < 0)
fprint(2, "can't open %s: %r\n", nvrfile);
else if (seek(loc.fd, loc.safeoff, 0) < 0)
fprint(2, "can't seek %s to %lld: %r\n",
nvrfile, loc.safeoff);
else
fprint(2, "can't read %d bytes from %s: %r\n",
loc.safelen, nvrfile);
/* start from scratch */
memset(safep, 0, sizeof(*safep));
safe = safep;
}else{
*safep = *safe; /* overwrite arg with data read */
safe = safep;
/* verify data read */
err |= check(safe->machkey, DESKEYLEN, safe->machsum,
"bad nvram des key");
err |= check(safe->authid, ANAMELEN, safe->authidsum,
"bad authentication id");
err |= check(safe->authdom, DOMLEN, safe->authdomsum,
"bad authentication domain");
if(0){
err |= check(safe->config, CONFIGLEN, safe->configsum,
"bad secstore key");
err |= check(safe->aesmachkey, AESKEYLEN, safe->aesmachsum,
"bad nvram aes key");
} else {
if(nvcsum(safe->config, CONFIGLEN) != safe->configsum)
memset(safe->config, 0, CONFIGLEN);
if(nvcsum(safe->aesmachkey, AESKEYLEN) != safe->aesmachsum)
memset(safe->aesmachkey, 0, AESKEYLEN);
}
if(err == 0)
if(safe->authid[0]==0 || safe->authdom[0]==0){
fprint(2, "empty nvram authid or authdom\n");
err = 1;
}
}
}
if((flag&(NVwrite|NVwritemem)) || (err && (flag&NVwriteonerr))){
if (!(flag&NVwritemem)) {
char pass[PASSWDLEN];
Authkey k;
if(ask("authid", safe->authid, sizeof safe->authid, 0))
goto Out;
if(ask("authdom", safe->authdom, sizeof safe->authdom, 0))
goto Out;
if(ask("secstore key", safe->config, sizeof safe->config, 1))
goto Out;
if(ask("password", pass, sizeof pass, 1))
goto Out;
passtokey(&k, pass);
memset(pass, 0, sizeof pass);
memmove(safe->machkey, k.des, DESKEYLEN);
memmove(safe->aesmachkey, k.aes, AESKEYLEN);
memset(&k, 0, sizeof k);
}
safe->machsum = nvcsum(safe->machkey, DESKEYLEN);
// safe->authsum = nvcsum(safe->authkey, DESKEYLEN);
safe->configsum = nvcsum(safe->config, CONFIGLEN);
safe->authidsum = nvcsum(safe->authid, sizeof safe->authid);
safe->authdomsum = nvcsum(safe->authdom, sizeof safe->authdom);
safe->aesmachsum = nvcsum(safe->aesmachkey, AESKEYLEN);
*(Nvrsafe*)buf = *safe;
if(loc.fd < 0
|| seek(loc.fd, loc.safeoff, 0) < 0
|| write(loc.fd, buf, loc.safelen) != loc.safelen){
fprint(2, "can't write key to nvram: %r\n");
err = 1;
}else
err = 0;
}
Out:
if (loc.fd >= 0)
close(loc.fd);
return err? -1: 0;
}
typedef struct Dosboot Dosboot;
struct Dosboot{
uchar magic[3]; /* really an xx86 JMP instruction */
uchar version[8];
uchar sectsize[2];
uchar clustsize;
uchar nresrv[2];
uchar nfats;
uchar rootsize[2];
uchar volsize[2];
uchar mediadesc;
uchar fatsize[2];
uchar trksize[2];
uchar nheads[2];
uchar nhidden[4];
uchar bigvolsize[4];
uchar driveno;
uchar reserved0;
uchar bootsig;
uchar volid[4];
uchar label[11];
uchar type[8];
};
#define GETSHORT(p) (((p)[1]<<8) | (p)[0])
#define GETLONG(p) ((GETSHORT((p)+2) << 16) | GETSHORT((p)))
typedef struct Dosdir Dosdir;
struct Dosdir
{
char name[8];
char ext[3];
uchar attr;
uchar reserved[10];
uchar time[2];
uchar date[2];
uchar start[2];
uchar length[4];
};
static char*
dosparse(char *from, char *to, int len)
{
char c;
memset(to, ' ', len);
if(from == 0)
return 0;
while(len-- > 0){
c = *from++;
if(c == '.')
return from;
if(c == 0)
break;
if(c >= 'a' && c <= 'z')
*to++ = c + 'A' - 'a';
else
*to++ = c;
}
return 0;
}
/*
* return offset of first file block
*
* This is a very simplistic dos file system. It only
* works on floppies, only looks in the root, and only
* returns a pointer to the first block of a file.
*
* This exists for cpu servers that have no hard disk
* or nvram to store the key on.
*
* Please don't make this any smarter: it stays resident
* and I'ld prefer not to waste the space on something that
* runs only at boottime -- presotto.
*/
static long
finddosfile(int fd, char *file)
{
uchar secbuf[512];
char name[8];
char ext[3];
Dosboot *b;
Dosdir *root, *dp;
int nroot, sectsize, rootoff, rootsects, n;
/* dos'ize file name */
file = dosparse(file, name, 8);
dosparse(file, ext, 3);
/* read boot block, check for sanity */
b = (Dosboot*)secbuf;
if(read(fd, secbuf, sizeof(secbuf)) != sizeof(secbuf))
return -1;
if(b->magic[0] != 0xEB || b->magic[1] != 0x3C || b->magic[2] != 0x90)
return -1;
sectsize = GETSHORT(b->sectsize);
if(sectsize != 512)
return -1;
rootoff = (GETSHORT(b->nresrv) + b->nfats*GETSHORT(b->fatsize)) * sectsize;
if(seek(fd, rootoff, 0) < 0)
return -1;
nroot = GETSHORT(b->rootsize);
rootsects = (nroot*sizeof(Dosdir)+sectsize-1)/sectsize;
if(rootsects <= 0 || rootsects > 64)
return -1;
/*
* read root. it is contiguous to make stuff like
* this easier
*/
root = malloc(rootsects*sectsize);
if(read(fd, root, rootsects*sectsize) != rootsects*sectsize)
return -1;
n = -1;
for(dp = root; dp < &root[nroot]; dp++)
if(memcmp(name, dp->name, 8) == 0 && memcmp(ext, dp->ext, 3) == 0){
n = GETSHORT(dp->start);
break;
}
free(root);
if(n < 0)
return -1;
/*
* dp->start is in cluster units, not sectors. The first
* cluster is cluster 2 which starts immediately after the
* root directory
*/
return rootoff + rootsects*sectsize + (n-2)*sectsize*b->clustsize;
}