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/*
* keyfs
*/
#include <u.h>
#include <libc.h>
#include <ctype.h>
#include <authsrv.h>
#include <fcall.h>
#include <bio.h>
#include <mp.h>
#include <libsec.h>
#include "authcmdlib.h"
#pragma varargck type "W" char*
char authkey[8];
typedef struct Fid Fid;
typedef struct User User;
enum {
Qroot,
Quser,
Qkey,
Qsecret,
Qlog,
Qstatus,
Qexpire,
Qwarnings,
Qmax,
Nuser = 512,
MAXBAD = 10, /* max # of bad attempts before disabling the account */
/* file must be randomly addressible, so names have fixed length */
Namelen = ANAMELEN,
};
enum {
Sok,
Sdisabled,
Smax,
};
struct Fid {
int fid;
ulong qtype;
User *user;
int busy;
Fid *next;
};
struct User {
char *name;
char key[DESKEYLEN];
char secret[SECRETLEN];
ulong expire; /* 0 == never */
uchar status;
ulong bad; /* # of consecutive bad authentication attempts */
int ref;
char removed;
uchar warnings;
long purgatory; /* time purgatory ends */
ulong uniq;
User *link;
};
char *qinfo[Qmax] = {
[Qroot] "keys",
[Quser] ".",
[Qkey] "key",
[Qsecret] "secret",
[Qlog] "log",
[Qexpire] "expire",
[Qstatus] "status",
[Qwarnings] "warnings",
};
char *status[Smax] = {
[Sok] "ok",
[Sdisabled] "disabled",
};
Fid *fids;
User *users[Nuser];
char *userkeys;
int nuser;
ulong uniq = 1;
Fcall rhdr,
thdr;
int usepass;
char *warnarg;
uchar mdata[8192 + IOHDRSZ];
int messagesize = sizeof mdata;
int readusers(void);
ulong hash(char*);
Fid *findfid(int);
User *finduser(char*);
User *installuser(char*);
int removeuser(User*);
void insertuser(User*);
void writeusers(void);
void io(int, int);
void *emalloc(ulong);
Qid mkqid(User*, ulong);
int dostat(User*, ulong, void*, int);
int newkeys(void);
void warning(void);
int weirdfmt(Fmt *f);
char *Auth(Fid*), *Attach(Fid*), *Version(Fid*),
*Flush(Fid*), *Walk(Fid*),
*Open(Fid*), *Create(Fid*),
*Read(Fid *), *Write(Fid*), *Clunk(Fid*),
*Remove(Fid *), *Stat(Fid*), *Wstat(Fid*);
char *(*fcalls[])(Fid*) = {
[Tattach] Attach,
[Tauth] Auth,
[Tclunk] Clunk,
[Tcreate] Create,
[Tflush] Flush,
[Topen] Open,
[Tread] Read,
[Tremove] Remove,
[Tstat] Stat,
[Tversion] Version,
[Twalk] Walk,
[Twrite] Write,
[Twstat] Wstat,
};
static void
usage(void)
{
fprint(2, "usage: %s [-p] [-m mtpt] [-w warn] [keyfile]\n", argv0);
exits("usage");
}
void
main(int argc, char *argv[])
{
char *mntpt;
int p[2];
fmtinstall('W', weirdfmt);
mntpt = "/mnt/keys";
ARGBEGIN{
case 'm':
mntpt = EARGF(usage());
break;
case 'p':
usepass = 1;
break;
case 'w':
warnarg = EARGF(usage());
break;
default:
usage();
break;
}ARGEND
argv0 = "keyfs";
userkeys = "/adm/keys";
if(argc > 1)
usage();
if(argc == 1)
userkeys = argv[0];
if(pipe(p) < 0)
error("can't make pipe: %r");
if(usepass) {
getpass(authkey, nil, 0, 0);
} else {
if(!getauthkey(authkey))
print("keyfs: warning: can't read NVRAM\n");
}
switch(rfork(RFPROC|RFNAMEG|RFNOTEG|RFNOWAIT|RFENVG|RFFDG)){
case 0:
close(p[0]);
io(p[1], p[1]);
exits(0);
case -1:
error("fork");
default:
close(p[1]);
if(mount(p[0], -1, mntpt, MREPL|MCREATE, "") < 0)
error("can't mount: %r");
exits(0);
}
}
char *
Flush(Fid *f)
{
USED(f);
return 0;
}
char *
Auth(Fid *)
{
return "keyfs: authentication not required";
}
char *
Attach(Fid *f)
{
if(f->busy)
Clunk(f);
f->user = 0;
f->qtype = Qroot;
f->busy = 1;
thdr.qid = mkqid(f->user, f->qtype);
return 0;
}
char*
Version(Fid*)
{
Fid *f;
for(f = fids; f; f = f->next)
if(f->busy)
Clunk(f);
if(rhdr.msize > sizeof mdata)
thdr.msize = sizeof mdata;
else
thdr.msize = rhdr.msize;
messagesize = thdr.msize;
if(strncmp(rhdr.version, "9P2000", 6) != 0)
return "bad 9P version";
thdr.version = "9P2000";
return 0;
}
char *
Walk(Fid *f)
{
char *name, *err;
int i, j, max;
Fid *nf;
ulong qtype;
User *user;
if(!f->busy)
return "walk of unused fid";
nf = nil;
qtype = f->qtype;
user = f->user;
if(rhdr.fid != rhdr.newfid){
nf = findfid(rhdr.newfid);
if(nf->busy)
return "fid in use";
f = nf; /* walk f */
}
err = nil;
i = 0;
if(rhdr.nwname > 0){
for(; i<rhdr.nwname; i++){
if(i >= MAXWELEM){
err = "too many path name elements";
break;
}
name = rhdr.wname[i];
switch(qtype){
case Qroot:
if(strcmp(name, "..") == 0)
goto Accept;
user = finduser(name);
if(!user)
goto Out;
qtype = Quser;
Accept:
thdr.wqid[i] = mkqid(user, qtype);
break;
case Quser:
if(strcmp(name, "..") == 0) {
qtype = Qroot;
user = 0;
goto Accept;
}
max = Qmax;
for(j = Quser + 1; j < Qmax; j++)
if(strcmp(name, qinfo[j]) == 0){
qtype = j;
break;
}
if(j < max)
goto Accept;
goto Out;
default:
err = "file is not a directory";
goto Out;
}
}
Out:
if(i < rhdr.nwname && err == nil)
err = "file not found";
}
if(err != nil){
return err;
}
/* if we cloned and then completed the walk, update new fid */
if(rhdr.fid != rhdr.newfid && i == rhdr.nwname){
nf->busy = 1;
nf->qtype = qtype;
if(nf->user = user)
nf->user->ref++;
}else if(nf == nil && rhdr.nwname > 0){ /* walk without clone (rare) */
Clunk(f);
f->busy = 1;
f->qtype = qtype;
if(f->user = user)
f->user->ref++;
}
thdr.nwqid = i;
return 0;
}
char *
Clunk(Fid *f)
{
f->busy = 0;
if(f->user && --f->user->ref == 0 && f->user->removed) {
free(f->user->name);
free(f->user);
}
f->user = 0;
return 0;
}
char *
Open(Fid *f)
{
int mode;
if(!f->busy)
return "open of unused fid";
mode = rhdr.mode;
if(f->qtype == Quser && (mode & (OWRITE|OTRUNC)))
return "user already exists";
thdr.qid = mkqid(f->user, f->qtype);
thdr.iounit = messagesize - IOHDRSZ;
return 0;
}
char *
Create(Fid *f)
{
char *name;
long perm;
if(!f->busy)
return "create of unused fid";
name = rhdr.name;
if(f->user){
return "permission denied";
}else{
perm = rhdr.perm;
if(!(perm & DMDIR))
return "permission denied";
if(strcmp(name, "") == 0)
return "empty file name";
if(strlen(name) >= Namelen)
return "file name too long";
if(finduser(name))
return "user already exists";
f->user = installuser(name);
f->user->ref++;
f->qtype = Quser;
}
thdr.qid = mkqid(f->user, f->qtype);
thdr.iounit = messagesize - IOHDRSZ;
writeusers();
return 0;
}
char *
Read(Fid *f)
{
User *u;
char *data;
ulong off, n, m;
int i, j, max;
if(!f->busy)
return "read of unused fid";
n = rhdr.count;
off = rhdr.offset;
thdr.count = 0;
data = thdr.data;
switch(f->qtype){
case Qroot:
j = 0;
for(i = 0; i < Nuser; i++)
for(u = users[i]; u; j += m, u = u->link){
m = dostat(u, Quser, data, n);
if(m <= BIT16SZ)
break;
if(j < off)
continue;
data += m;
n -= m;
}
thdr.count = data - thdr.data;
return 0;
case Quser:
max = Qmax;
max -= Quser + 1;
j = 0;
for(i = 0; i < max; j += m, i++){
m = dostat(f->user, i + Quser + 1, data, n);
if(m <= BIT16SZ)
break;
if(j < off)
continue;
data += m;
n -= m;
}
thdr.count = data - thdr.data;
return 0;
case Qkey:
if(f->user->status != Sok)
return "user disabled";
if(f->user->purgatory > time(0))
return "user in purgatory";
if(f->user->expire != 0 && f->user->expire < time(0))
return "user expired";
if(off != 0)
return 0;
if(n > DESKEYLEN)
n = DESKEYLEN;
memmove(thdr.data, f->user->key, n);
thdr.count = n;
return 0;
case Qsecret:
if(f->user->status != Sok)
return "user disabled";
if(f->user->purgatory > time(0))
return "user in purgatory";
if(f->user->expire != 0 && f->user->expire < time(0))
return "user expired";
if(off != 0)
return 0;
if(n > strlen(f->user->secret))
n = strlen(f->user->secret);
memmove(thdr.data, f->user->secret, n);
thdr.count = n;
return 0;
case Qstatus:
if(off != 0){
thdr.count = 0;
return 0;
}
if(f->user->status == Sok && f->user->expire && f->user->expire < time(0))
sprint(thdr.data, "expired\n");
else
sprint(thdr.data, "%s\n", status[f->user->status]);
thdr.count = strlen(thdr.data);
return 0;
case Qexpire:
if(off != 0){
thdr.count = 0;
return 0;
}
if(!f->user->expire)
strcpy(data, "never\n");
else
sprint(data, "%lud\n", f->user->expire);
if(n > strlen(data))
n = strlen(data);
thdr.count = n;
return 0;
case Qlog:
if(off != 0){
thdr.count = 0;
return 0;
}
sprint(data, "%lud\n", f->user->bad);
if(n > strlen(data))
n = strlen(data);
thdr.count = n;
return 0;
case Qwarnings:
if(off != 0){
thdr.count = 0;
return 0;
}
sprint(data, "%ud\n", f->user->warnings);
if(n > strlen(data))
n = strlen(data);
thdr.count = n;
return 0;
default:
return "permission denied: unknown qid";
}
}
char *
Write(Fid *f)
{
char *data, *p;
ulong n, expire;
int i;
if(!f->busy)
return "permission denied";
n = rhdr.count;
data = rhdr.data;
switch(f->qtype){
case Qkey:
if(n != DESKEYLEN)
return "garbled write data";
memmove(f->user->key, data, DESKEYLEN);
thdr.count = DESKEYLEN;
break;
case Qsecret:
if(n >= SECRETLEN)
return "garbled write data";
memmove(f->user->secret, data, n);
f->user->secret[n] = 0;
thdr.count = n;
break;
case Qstatus:
data[n] = '\0';
if(p = strchr(data, '\n'))
*p = '\0';
for(i = 0; i < Smax; i++)
if(strcmp(data, status[i]) == 0){
f->user->status = i;
break;
}
if(i == Smax)
return "unknown status";
f->user->bad = 0;
thdr.count = n;
break;
case Qexpire:
data[n] = '\0';
if(p = strchr(data, '\n'))
*p = '\0';
else
p = &data[n];
if(strcmp(data, "never") == 0)
expire = 0;
else{
expire = strtoul(data, &data, 10);
if(data != p)
return "bad expiration date";
}
f->user->expire = expire;
f->user->warnings = 0;
thdr.count = n;
break;
case Qlog:
data[n] = '\0';
if(strcmp(data, "good") == 0)
f->user->bad = 0;
else
f->user->bad++;
if(f->user->bad && ((f->user->bad)%MAXBAD) == 0)
f->user->purgatory = time(0) + f->user->bad;
return 0;
case Qwarnings:
data[n] = '\0';
f->user->warnings = strtoul(data, 0, 10);
thdr.count = n;
break;
case Qroot:
case Quser:
default:
return "permission denied";
}
writeusers();
return 0;
}
char *
Remove(Fid *f)
{
if(!f->busy)
return "permission denied";
if(f->qtype == Qwarnings)
f->user->warnings = 0;
else if(f->qtype == Quser)
removeuser(f->user);
else {
Clunk(f);
return "permission denied";
}
Clunk(f);
writeusers();
return 0;
}
char *
Stat(Fid *f)
{
static uchar statbuf[1024];
if(!f->busy)
return "stat on unattached fid";
thdr.nstat = dostat(f->user, f->qtype, statbuf, sizeof statbuf);
if(thdr.nstat <= BIT16SZ)
return "stat buffer too small";
thdr.stat = statbuf;
return 0;
}
char *
Wstat(Fid *f)
{
Dir d;
int n;
char buf[1024];
if(!f->busy || f->qtype != Quser)
return "permission denied";
if(rhdr.nstat > sizeof buf)
return "wstat buffer too big";
if(convM2D(rhdr.stat, rhdr.nstat, &d, buf) == 0)
return "bad stat buffer";
n = strlen(d.name);
if(n == 0 || n >= Namelen)
return "bad user name";
if(finduser(d.name))
return "user already exists";
if(!removeuser(f->user))
return "user previously removed";
free(f->user->name);
f->user->name = strdup(d.name);
if(f->user->name == nil)
error("wstat: malloc failed: %r");
insertuser(f->user);
writeusers();
return 0;
}
Qid
mkqid(User *u, ulong qtype)
{
Qid q;
q.vers = 0;
q.path = qtype;
if(u)
q.path |= u->uniq * 0x100;
if(qtype == Quser || qtype == Qroot)
q.type = QTDIR;
else
q.type = QTFILE;
return q;
}
int
dostat(User *user, ulong qtype, void *p, int n)
{
Dir d;
if(qtype == Quser)
d.name = user->name;
else
d.name = qinfo[qtype];
d.uid = d.gid = d.muid = "auth";
d.qid = mkqid(user, qtype);
if(d.qid.type & QTDIR)
d.mode = 0777|DMDIR;
else
d.mode = 0666;
d.atime = d.mtime = time(0);
d.length = 0;
return convD2M(&d, p, n);
}
int
passline(Biobuf *b, void *vbuf)
{
char *buf = vbuf;
if(Bread(b, buf, KEYDBLEN) != KEYDBLEN)
return 0;
decrypt(authkey, buf, KEYDBLEN);
buf[Namelen-1] = '\0';
return 1;
}
void
randombytes(uchar *p, int len)
{
int i, fd;
fd = open("/dev/random", OREAD);
if(fd < 0){
fprint(2, "keyfs: can't open /dev/random, using rand()\n");
srand(time(0));
for(i = 0; i < len; i++)
p[i] = rand();
return;
}
read(fd, p, len);
close(fd);
}
void
oldCBCencrypt(char *key7, uchar *p, int len)
{
uchar ivec[8];
uchar key[8];
DESstate s;
memset(ivec, 0, 8);
des56to64((uchar*)key7, key);
setupDESstate(&s, key, ivec);
desCBCencrypt((uchar*)p, len, &s);
}
void
oldCBCdecrypt(char *key7, uchar *p, int len)
{
uchar ivec[8];
uchar key[8];
DESstate s;
memset(ivec, 0, 8);
des56to64((uchar*)key7, key);
setupDESstate(&s, key, ivec);
desCBCdecrypt((uchar*)p, len, &s);
}
void
writeusers(void)
{
int fd, i, nu;
User *u;
uchar *p, *buf;
ulong expire;
/* count users */
nu = 0;
for(i = 0; i < Nuser; i++)
for(u = users[i]; u; u = u->link)
nu++;
/* pack into buffer */
buf = malloc(KEYDBOFF + nu*KEYDBLEN);
if(buf == 0){
fprint(2, "keyfs: can't write keys file, out of memory\n");
return;
}
p = buf;
randombytes(p, KEYDBOFF);
p += KEYDBOFF;
for(i = 0; i < Nuser; i++)
for(u = users[i]; u; u = u->link){
strncpy((char*)p, u->name, Namelen);
p += Namelen;
memmove(p, u->key, DESKEYLEN);
p += DESKEYLEN;
*p++ = u->status;
*p++ = u->warnings;
expire = u->expire;
*p++ = expire;
*p++ = expire >> 8;
*p++ = expire >> 16;
*p++ = expire >> 24;
memmove(p, u->secret, SECRETLEN);
p += SECRETLEN;
}
/* encrypt */
oldCBCencrypt(authkey, buf, p - buf);
/* write file */
fd = create(userkeys, OWRITE, 0660);
if(fd < 0){
free(buf);
fprint(2, "keyfs: can't write keys file\n");
return;
}
if(write(fd, buf, p - buf) != (p - buf))
fprint(2, "keyfs: can't write keys file\n");
free(buf);
close(fd);
}
int
weirdfmt(Fmt *f)
{
char *s, *p, *ep, buf[ANAMELEN*4 + 1];
int i, n;
Rune r;
s = va_arg(f->args, char*);
p = buf;
ep = buf + sizeof buf;
for(i = 0; i < ANAMELEN; i += n){
n = chartorune(&r, s + i);
if(r == Runeerror)
p = seprint(p, ep, "[%.2x]", buf[i]);
else if(isascii(r) && iscntrl(r))
p = seprint(p, ep, "[%.2x]", r);
else if(r == ' ' || r == '/')
p = seprint(p, ep, "[%c]", r);
else
p = seprint(p, ep, "%C", r);
}
return fmtstrcpy(f, buf);
}
int
userok(char *user, int nu)
{
int i, n, rv;
Rune r;
char buf[ANAMELEN+1];
memset(buf, 0, sizeof buf);
memmove(buf, user, ANAMELEN);
if(buf[ANAMELEN-1] != 0){
fprint(2, "keyfs: %d: no termination: %W\n", nu, buf);
return -1;
}
rv = 0;
for(i = 0; buf[i]; i += n){
n = chartorune(&r, buf+i);
if(r == Runeerror){
// fprint(2, "keyfs: name %W bad rune byte %d\n", buf, i);
rv = -1;
} else if(isascii(r) && iscntrl(r) || r == ' ' || r == '/'){
// fprint(2, "keyfs: name %W bad char %C\n", buf, r);
rv = -1;
}
}
if(i == 0){
fprint(2, "keyfs: %d: nil name\n", nu);
return -1;
}
if(rv == -1)
fprint(2, "keyfs: %d: bad syntax: %W\n", nu, buf);
return rv;
}
int
readusers(void)
{
int fd, i, n, nu;
uchar *p, *buf, *ep;
User *u;
Dir *d;
/* read file into an array */
fd = open(userkeys, OREAD);
if(fd < 0)
return 0;
d = dirfstat(fd);
if(d == nil){
close(fd);
return 0;
}
buf = malloc(d->length);
if(buf == 0){
close(fd);
free(d);
return 0;
}
n = readn(fd, buf, d->length);
close(fd);
free(d);
if(n != d->length){
free(buf);
return 0;
}
/* decrypt */
n -= n % KEYDBLEN;
oldCBCdecrypt(authkey, buf, n);
/* unpack */
nu = 0;
for(i = KEYDBOFF; i < n; i += KEYDBLEN){
ep = buf + i;
if(userok((char*)ep, i/KEYDBLEN) < 0)
continue;
u = finduser((char*)ep);
if(u == 0)
u = installuser((char*)ep);
memmove(u->key, ep + Namelen, DESKEYLEN);
p = ep + Namelen + DESKEYLEN;
u->status = *p++;
u->warnings = *p++;
if(u->status >= Smax)
fprint(2, "keyfs: warning: bad status in key file\n");
u->expire = p[0] + (p[1]<<8) + (p[2]<<16) + (p[3]<<24);
p += 4;
memmove(u->secret, p, SECRETLEN);
u->secret[SECRETLEN-1] = 0;
nu++;
}
free(buf);
print("%d keys read\n", nu);
return 1;
}
User *
installuser(char *name)
{
User *u;
int h;
h = hash(name);
u = emalloc(sizeof *u);
u->name = strdup(name);
if(u->name == nil)
error("malloc failed: %r");
u->removed = 0;
u->ref = 0;
u->purgatory = 0;
u->expire = 0;
u->status = Sok;
u->bad = 0;
u->warnings = 0;
u->uniq = uniq++;
u->link = users[h];
users[h] = u;
return u;
}
User *
finduser(char *name)
{
User *u;
for(u = users[hash(name)]; u; u = u->link)
if(strcmp(name, u->name) == 0)
return u;
return 0;
}
int
removeuser(User *user)
{
User *u, **last;
char *name;
user->removed = 1;
name = user->name;
last = &users[hash(name)];
for(u = *last; u; u = *last){
if(strcmp(name, u->name) == 0){
*last = u->link;
return 1;
}
last = &u->link;
}
return 0;
}
void
insertuser(User *user)
{
int h;
user->removed = 0;
h = hash(user->name);
user->link = users[h];
users[h] = user;
}
ulong
hash(char *s)
{
ulong h;
h = 0;
while(*s)
h = (h << 1) ^ *s++;
return h % Nuser;
}
Fid *
findfid(int fid)
{
Fid *f, *ff;
ff = 0;
for(f = fids; f; f = f->next)
if(f->fid == fid)
return f;
else if(!ff && !f->busy)
ff = f;
if(ff){
ff->fid = fid;
return ff;
}
f = emalloc(sizeof *f);
f->fid = fid;
f->busy = 0;
f->user = 0;
f->next = fids;
fids = f;
return f;
}
void
io(int in, int out)
{
char *err;
int n;
long now, lastwarning;
/* after restart, let the system settle for 5 mins before warning */
lastwarning = time(0) - 24*60*60 + 5*60;
for(;;){
n = read9pmsg(in, mdata, messagesize);
if(n == 0)
continue;
if(n < 0)
error("mount read %d", n);
if(convM2S(mdata, n, &rhdr) == 0)
continue;
if(newkeys())
readusers();
thdr.data = (char*)mdata + IOHDRSZ;
thdr.fid = rhdr.fid;
if(!fcalls[rhdr.type])
err = "fcall request";
else
err = (*fcalls[rhdr.type])(findfid(rhdr.fid));
thdr.tag = rhdr.tag;
thdr.type = rhdr.type+1;
if(err){
thdr.type = Rerror;
thdr.ename = err;
}
n = convS2M(&thdr, mdata, messagesize);
if(write(out, mdata, n) != n)
error("mount write");
now = time(0);
if(warnarg && (now - lastwarning > 24*60*60)){
syslog(0, "auth", "keyfs starting warnings: %lux %lux",
now, lastwarning);
warning();
lastwarning = now;
}
}
}
int
newkeys(void)
{
Dir *d;
static long ftime;
d = dirstat(userkeys);
if(d == nil)
return 0;
if(d->mtime > ftime){
ftime = d->mtime;
free(d);
return 1;
}
free(d);
return 0;
}
void *
emalloc(ulong n)
{
void *p;
if(p = malloc(n))
return p;
error("out of memory");
return 0; /* not reached */
}
void
warning(void)
{
int i;
char buf[64];
snprint(buf, sizeof buf, "-%s", warnarg);
switch(rfork(RFPROC|RFNAMEG|RFNOTEG|RFNOWAIT|RFENVG|RFFDG)){
case 0:
i = open("/sys/log/auth", OWRITE);
if(i >= 0){
dup(i, 2);
seek(2, 0, 2);
close(i);
}
execl("/bin/auth/warning", "warning", warnarg, nil);
error("can't exec warning");
}
}