ref: fe1eb39db7ae6904924f3ab1f6f9b34416f2eb1b
dir: /sys/src/cmd/auth/factotum/util.c/
#include "dat.h"
static char secstore[100]; /* server name */
static uchar zeros[16];
/* bind in the default network and cs */
static int
bindnetcs(void)
{
int srvfd;
if(access("/net/tcp", AEXIST) < 0)
bind("#I", "/net", MBEFORE);
if(access("/net/cs", AEXIST) < 0){
if((srvfd = open("/srv/cs", ORDWR)) >= 0){
if(mount(srvfd, -1, "/net", MBEFORE, "") != -1)
return 0;
close(srvfd);
}
return -1;
}
return 0;
}
/* get all auth= attribute values from /net/ndb */
static void
netndbauthaddr(void)
{
enum { CHUNK = 1024 };
char *b, *p, *e;
int fd, n, m, i;
if((fd = open("/net/ndb", OREAD)) < 0)
return;
m = 0;
b = nil;
for(;;){
if((p = realloc(b, m+CHUNK+1)) == nil)
break;
b = p;
if((n = read(fd, b+m, CHUNK)) <= 0)
break;
m += n;
}
close(fd);
if(b == nil)
return;
b[m] = '\0';
i = 0;
e = b;
while((p = strstr(e, "auth=")) != nil){
if(p > e && strchr("\n\t ", p[-1]) == nil){
e = p + strlen("auth=");
continue;
}
p += strlen("auth=");
for(e = p; *e != '\0'; e++)
if(strchr("\n\t ", *e) != nil)
break;
if(*e == '\0')
break;
*e++ = '\0';
if(*p == '\0')
continue;
authaddr[i++] = estrdup(p);
if(i >= nelem(authaddr)-1)
break;
}
authaddr[i] = nil;
free(b);
}
int
_authdial(char *authdom)
{
int i, fd;
alarm(30*1000);
if(bindnetcs()>=0)
fd = authdial(nil, authdom);
else {
/*
* If we failed to mount /srv/cs, assume that
* we're still bootstrapping the system and dial
* the one auth server passed to us on the command line or
* look for auth= attributes in /net/ndb.
* In normal operation, it is important *not* to do this,
* because the bootstrap auth server is only good for
* a single auth domain.
*
* The ticket request code should really check the
* remote authentication domain too.
*/
fd = -1;
if(authaddr[0] == nil)
netndbauthaddr();
for(i = 0; fd < 0 && authaddr[i] != nil; i++){
fd = dial(netmkaddr(authaddr[i], "tcp", "567"), 0, 0, 0);
if(fd < 0)
fd = dial(netmkaddr(authaddr[i], "il", "566"), 0, 0, 0);
}
}
alarm(0);
return fd;
}
int
_authreq(Ticketreq *tr, Authkey *k)
{
int fd;
fd = _authdial(tr->authdom);
if(fd < 0)
return -1;
alarm(30*1000);
if(tsmemcmp(k->aes, zeros, AESKEYLEN) != 0){
if(_asgetpakkey(fd, tr, k) < 0){
alarm(0);
close(fd);
return -1;
}
}
if(_asrequest(fd, tr) < 0){
alarm(0);
close(fd);
return -1;
}
alarm(0);
return fd;
}
/*
* prompt user for a key. don't care about memory leaks, runs standalone
*/
static Attr*
promptforkey(char *params)
{
char *v;
int fd;
Attr *a, *attr;
char *def;
fd = open("/dev/cons", ORDWR);
if(fd < 0)
sysfatal("opening /dev/cons: %r");
attr = _parseattr(params);
fprint(fd, "\n!Adding key:");
for(a=attr; a; a=a->next)
if(a->type != AttrQuery && a->name[0] != '!')
fprint(fd, " %q=%q", a->name, a->val);
fprint(fd, "\n");
for(a=attr; a; a=a->next){
v = a->name;
if(a->type != AttrQuery || v[0]=='!')
continue;
def = nil;
if(strcmp(v, "user") == 0)
def = getuser();
a->val = readcons(v, def, 0);
if(a->val == nil)
sysfatal("user terminated key input");
a->type = AttrNameval;
}
for(a=attr; a; a=a->next){
v = a->name;
if(a->type != AttrQuery || v[0]!='!')
continue;
def = nil;
if(strcmp(v+1, "user") == 0)
def = getuser();
a->val = readcons(v+1, def, 1);
if(a->val == nil)
sysfatal("user terminated key input");
a->type = AttrNameval;
}
fprint(fd, "!\n");
close(fd);
return attr;
}
/*
* send a key to the mounted factotum
*/
static int
sendkey(Attr *attr)
{
int fd, rv;
char buf[1024];
fd = open("/mnt/factotum/ctl", ORDWR);
if(fd < 0)
sysfatal("opening /mnt/factotum/ctl: %r");
rv = fprint(fd, "key %A\n", attr);
read(fd, buf, sizeof buf);
close(fd);
return rv;
}
/* askuser */
void
askuser(char *params)
{
Attr *attr;
attr = promptforkey(params);
if(attr == nil)
sysfatal("no key supplied");
if(sendkey(attr) < 0)
sysfatal("sending key to factotum: %r");
}
ulong conftaggen;
int
canusekey(Fsstate *fss, Key *k)
{
int i;
if(_strfindattr(k->attr, "confirm")){
for(i=0; i<fss->nconf; i++)
if(fss->conf[i].key == k)
return fss->conf[i].canuse;
if(fss->nconf%16 == 0)
fss->conf = erealloc(fss->conf, (fss->nconf+16)*(sizeof(fss->conf[0])));
incref(k);
fss->conf[fss->nconf].key = k;
fss->conf[fss->nconf].canuse = -1;
fss->conf[fss->nconf].tag = conftaggen++;
fss->nconf++;
return -1;
}
return 1;
}
/* closekey */
void
closekey(Key *k)
{
if(k == nil)
return;
if(decref(k))
return;
if(k->proto && k->proto->closekey)
(*k->proto->closekey)(k);
_freeattr(k->attr);
_freeattr(k->privattr);
k->attr = (void*)~1;
k->privattr = (void*)~1;
k->proto = nil;
free(k);
}
static uchar*
pstring(uchar *p, uchar *e, char *s)
{
uint n;
if(p == nil)
return nil;
if(s == nil)
s = "";
n = strlen(s);
if(p+n+BIT16SZ >= e)
return nil;
PBIT16(p, n);
p += BIT16SZ;
memmove(p, s, n);
p += n;
return p;
}
static uchar*
pcarray(uchar *p, uchar *e, uchar *s, uint n)
{
if(p == nil)
return nil;
if(s == nil){
if(n > 0)
sysfatal("pcarray");
s = (uchar*)"";
}
if(p+n+BIT16SZ >= e)
return nil;
PBIT16(p, n);
p += BIT16SZ;
memmove(p, s, n);
p += n;
return p;
}
uchar*
convAI2M(AuthInfo *ai, uchar *p, int n)
{
uchar *e = p+n;
p = pstring(p, e, ai->cuid);
p = pstring(p, e, ai->suid);
p = pstring(p, e, ai->cap);
p = pcarray(p, e, ai->secret, ai->nsecret);
return p;
}
int
failure(Fsstate *s, char *fmt, ...)
{
char e[ERRMAX];
va_list arg;
if(fmt == nil)
rerrstr(s->err, sizeof(s->err));
else {
va_start(arg, fmt);
vsnprint(e, sizeof e, fmt, arg);
va_end(arg);
strecpy(s->err, s->err+sizeof(s->err), e);
errstr(e, sizeof e);
}
flog("%d: failure %s", s->seqnum, s->err);
return RpcFailure;
}
static int
hasqueries(Attr *a)
{
for(; a; a=a->next)
if(a->type == AttrQuery)
return 1;
return 0;
}
char *ignored[] = {
"role",
"disabled",
};
static int
ignoreattr(char *s)
{
int i;
for(i=0; i<nelem(ignored); i++)
if(strcmp(ignored[i], s)==0)
return 1;
return 0;
}
Keyinfo*
mkkeyinfo(Keyinfo *k, Fsstate *fss, Attr *attr)
{
memset(k, 0, sizeof *k);
k->fss = fss;
k->user = fss->sysuser;
if(attr)
k->attr = attr;
else
k->attr = fss->attr;
return k;
}
int
findkey(Key **ret, Keyinfo *ki, char *fmt, ...)
{
int i, s, nmatch;
char buf[1024], *p, *who;
va_list arg;
Attr *a, *attr0, *attr1, *attr2, *attr3, **l;
Key *k;
*ret = nil;
who = ki->user;
attr0 = ki->attr;
if(fmt){
va_start(arg, fmt);
vseprint(buf, buf+sizeof buf, fmt, arg);
va_end(arg);
attr1 = _parseattr(buf);
}else
attr1 = nil;
if(who && strcmp(who, owner) == 0)
who = nil;
if(who){
snprint(buf, sizeof buf, "owner=%q", who);
attr2 = _parseattr(buf);
attr3 = _parseattr("owner=*");
}else
attr2 = attr3 = nil;
p = _strfindattr(attr0, "proto");
if(p == nil)
p = _strfindattr(attr1, "proto");
if(p && findproto(p) == nil){
werrstr("unknown protocol %s", p);
_freeattr(attr1);
_freeattr(attr2);
_freeattr(attr3);
return failure(ki->fss, nil);
}
qlock(ring);
nmatch = 0;
for(i=0; i<ring->nkey; i++){
k = ring->key[i];
if(_strfindattr(k->attr, "disabled") && !ki->usedisabled)
continue;
if(matchattr(attr0, k->attr, k->privattr) && matchattr(attr1, k->attr, k->privattr)){
/* check ownership */
if(!matchattr(attr2, k->attr, nil) && !matchattr(attr3, k->attr, nil))
continue;
if(nmatch++ < ki->skip)
continue;
if(!ki->noconf){
switch(canusekey(ki->fss, k)){
case -1:
qunlock(ring);
_freeattr(attr1);
_freeattr(attr2);
_freeattr(attr3);
return RpcConfirm;
case 0:
continue;
case 1:
break;
}
}
_freeattr(attr1);
_freeattr(attr2);
_freeattr(attr3);
incref(k);
*ret = k;
qunlock(ring);
return RpcOk;
}
}
qunlock(ring);
flog("%d: no key matches %A %A %A %A", ki->fss->seqnum, attr0, attr1, attr2, attr3);
werrstr("no key matches %A %A", attr0, attr1);
_freeattr(attr2);
_freeattr(attr3);
s = RpcFailure;
if(askforkeys && who==nil && (hasqueries(attr0) || hasqueries(attr1))){
if(nmatch == 0){
attr0 = _copyattr(attr0);
for(l=&attr0; *l; l=&(*l)->next)
;
*l = attr1;
for(l=&attr0; *l; ){
if(ignoreattr((*l)->name)){
a = *l;
*l = (*l)->next;
a->next = nil;
_freeattr(a);
}else
l = &(*l)->next;
}
attr0 = sortattr(attr0);
snprint(ki->fss->keyinfo, sizeof ki->fss->keyinfo, "%A", attr0);
_freeattr(attr0);
attr1 = nil; /* attr1 was linked to attr0 */
}else
ki->fss->keyinfo[0] = '\0';
s = RpcNeedkey;
}
_freeattr(attr1);
if(s == RpcFailure)
return failure(ki->fss, nil); /* loads error string */
return s;
}
int
findp9authkey(Key **k, Fsstate *fss)
{
char *dom;
Keyinfo ki;
int rv;
/*
* We don't use fss->attr here because we don't
* care about what the user name is set to, for instance.
*/
mkkeyinfo(&ki, fss, nil);
ki.attr = nil;
ki.user = nil;
dom = _strfindattr(fss->attr, "dom");
if(dom != nil)
rv = findkey(k, &ki, "proto=dp9ik dom=%q role=server user?", dom);
else
rv = findkey(k, &ki, "proto=dp9ik role=server dom? user?");
if(rv != RpcOk){
if(dom != nil)
rv = findkey(k, &ki, "proto=p9sk1 dom=%q role=server user?", dom);
else
rv = findkey(k, &ki, "proto=p9sk1 role=server dom? user?");
}
return rv;
}
Proto*
findproto(char *name)
{
int i;
for(i=0; prototab[i]; i++)
if(strcmp(name, prototab[i]->name) == 0)
return prototab[i];
return nil;
}
int
getnvramkey(int flag)
{
Nvrsafe safe;
char *s;
memset(&safe, 0, sizeof safe);
/*
* readnvram can return -1 meaning nvram wasn't written,
* but safe still holds good data.
*/
if(readnvram(&safe, flag)<0 && safe.authid[0]==0)
return -1;
if(tsmemcmp(safe.machkey, zeros, DESKEYLEN) != 0){
s = smprint("key proto=p9sk1 user=%q dom=%q !hex=%.*H !password=______",
safe.authid, safe.authdom, DESKEYLEN, safe.machkey);
if(s != nil){
ctlwrite(s, 0);
memset(s, 0, strlen(s));
free(s);
}
}
if(tsmemcmp(safe.aesmachkey, zeros, AESKEYLEN) != 0){
s = smprint("key proto=dp9ik user=%q dom=%q !hex=%.*H !password=______",
safe.authid, safe.authdom, AESKEYLEN, safe.aesmachkey);
if(s != nil){
ctlwrite(s, 0);
memset(s, 0, strlen(s));
free(s);
}
}
writehostowner(safe.authid);
memset(&safe, 0, sizeof safe);
return 0;
}
int
isclient(char *role)
{
if(role == nil){
werrstr("role not specified");
return -1;
}
if(strcmp(role, "server") == 0)
return 0;
if(strcmp(role, "client") == 0)
return 1;
werrstr("unknown role %q", role);
return -1;
}
static int
hasname(Attr *a0, Attr *a1, char *name)
{
return _findattr(a0, name) || _findattr(a1, name);
}
static int
hasnameval(Attr *a0, Attr *a1, char *name, char *val)
{
Attr *a;
for(a=_findattr(a0, name); a; a=_findattr(a->next, name))
if(strcmp(a->val, val) == 0)
return 1;
for(a=_findattr(a1, name); a; a=_findattr(a->next, name))
if(strcmp(a->val, val) == 0)
return 1;
return 0;
}
int
matchattr(Attr *pat, Attr *a0, Attr *a1)
{
int type;
for(; pat; pat=pat->next){
type = pat->type;
if(ignoreattr(pat->name))
type = AttrDefault;
switch(type){
case AttrQuery: /* name=something be present */
if(!hasname(a0, a1, pat->name))
return 0;
break;
case AttrNameval: /* name=val must be present */
if(!hasnameval(a0, a1, pat->name, pat->val))
return 0;
break;
case AttrDefault: /* name=val must be present if name=anything is present */
if(hasname(a0, a1, pat->name) && !hasnameval(a0, a1, pat->name, pat->val))
return 0;
break;
}
}
return 1;
}
/*
* keep caphash fd open since opens of it could be disabled
*/
static int caphashfd;
void
initcap(void)
{
caphashfd = open("/dev/caphash", OCEXEC|OWRITE);
// if(caphashfd < 0)
// fprint(2, "%s: opening /dev/caphash: %r\n", argv0);
}
/*
* create a change uid capability
*/
char*
mkcap(char *from, char *to)
{
uchar rand[20];
char *cap;
char *key;
int nfrom, nto;
uchar hash[SHA1dlen];
if(caphashfd < 0)
return nil;
/* create the capability */
nto = strlen(to);
nfrom = strlen(from);
cap = emalloc(nfrom+1+nto+1+sizeof(rand)*3+1);
sprint(cap, "%s@%s", from, to);
genrandom(rand, sizeof(rand));
key = cap+nfrom+1+nto+1;
enc64(key, sizeof(rand)*3, rand, sizeof(rand));
/* hash the capability */
hmac_sha1((uchar*)cap, strlen(cap), (uchar*)key, strlen(key), hash, nil);
/* give the kernel the hash */
key[-1] = '@';
if(write(caphashfd, hash, SHA1dlen) < 0){
free(cap);
return nil;
}
return cap;
}
int
phaseerror(Fsstate *s, char *op)
{
char tmp[32];
werrstr("protocol phase error: %s in state %s", op, phasename(s, s->phase, tmp));
return RpcPhase;
}
char*
phasename(Fsstate *fss, int phase, char *tmp)
{
char *name;
if(fss->phase == Broken)
name = "Broken";
else if(phase == Established)
name = "Established";
else if(phase == Notstarted)
name = "Notstarted";
else if(phase < 0 || phase >= fss->maxphase
|| (name = fss->phasename[phase]) == nil){
sprint(tmp, "%d", phase);
name = tmp;
}
return name;
}
/*
* get host owner and set it
*/
void
promptforhostowner(void)
{
char *p;
/* hack for bitsy; can't prompt during boot */
p = getenv("user");
while(p == nil || *p == 0){
free(p);
p = readcons("user", "glenda", 0);
if(p == nil)
return;
}
writehostowner(p);
free(p);
}
/*
* Insert a key into the keyring.
* If the public attributes are identical to some other key, replace that one.
*/
int
replacekey(Key *kn, int before)
{
int i;
Key *k;
qlock(ring);
incref(kn);
for(i=0; i<ring->nkey; i++){
k = ring->key[i];
if(matchattr(kn->attr, k->attr, nil) && matchattr(k->attr, kn->attr, nil)){
ring->key[i] = kn;
qunlock(ring);
closekey(k);
return 0;
}
}
if(ring->nkey%16 == 0)
ring->key = erealloc(ring->key, (ring->nkey+16)*sizeof(ring->key[0]));
if(before){
memmove(ring->key+1, ring->key, ring->nkey*sizeof ring->key[0]);
ring->key[0] = kn;
ring->nkey++;
}else
ring->key[ring->nkey++] = kn;
qunlock(ring);
return 0;
}
char*
safecpy(char *to, char *from, int n)
{
memset(to, 0, n);
if(n == 1)
return to;
if(from==nil)
sysfatal("safecpy called with from==nil, pc=%#p",
getcallerpc(&to));
strncpy(to, from, n-1);
return to;
}
Attr*
setattr(Attr *a, char *fmt, ...)
{
char buf[1024];
va_list arg;
Attr *b;
va_start(arg, fmt);
vseprint(buf, buf+sizeof buf, fmt, arg);
va_end(arg);
b = _parseattr(buf);
a = setattrs(a, b);
setmalloctag(a, getcallerpc(&a));
_freeattr(b);
return a;
}
/*
* add attributes in list b to list a. If any attributes are in
* both lists, replace those in a by those in b.
*/
Attr*
setattrs(Attr *a, Attr *b)
{
int found;
Attr **l, *freea;
for(; b; b=b->next){
found = 0;
for(l=&a; *l; ){
if(strcmp(b->name, (*l)->name) == 0){
switch(b->type){
case AttrNameval:
if(!found){
found = 1;
free((*l)->val);
(*l)->val = estrdup(b->val);
(*l)->type = AttrNameval;
l = &(*l)->next;
}else{
freea = *l;
*l = (*l)->next;
freea->next = nil;
_freeattr(freea);
}
break;
case AttrQuery:
goto continue2;
}
}else
l = &(*l)->next;
}
if(found == 0){
*l = _mkattr(b->type, b->name, b->val, nil);
setmalloctag(*l, getcallerpc(&a));
}
continue2:;
}
return a;
}
void
setmalloctaghere(void *v)
{
setmalloctag(v, getcallerpc(&v));
}
Attr*
sortattr(Attr *a)
{
int i;
Attr *anext, *a0, *a1, **l;
if(a == nil || a->next == nil)
return a;
/* cut list in halves */
a0 = nil;
a1 = nil;
i = 0;
for(; a; a=anext){
anext = a->next;
if(i++%2){
a->next = a0;
a0 = a;
}else{
a->next = a1;
a1 = a;
}
}
/* sort */
a0 = sortattr(a0);
a1 = sortattr(a1);
/* merge */
l = &a;
while(a0 || a1){
if(a1==nil){
anext = a0;
a0 = a0->next;
}else if(a0==nil){
anext = a1;
a1 = a1->next;
}else if(strcmp(a0->name, a1->name) < 0){
anext = a0;
a0 = a0->next;
}else{
anext = a1;
a1 = a1->next;
}
*l = anext;
l = &(*l)->next;
}
*l = nil;
return a;
}
int
toosmall(Fsstate *fss, uint n)
{
fss->rpc.nwant = n;
return RpcToosmall;
}
void
writehostowner(char *owner)
{
int fd;
char *s;
if((s = strchr(owner,'@')) != nil)
*s = 0;
fd = open("/dev/hostowner", OWRITE|OCEXEC);
if(fd >= 0){
if(fprint(fd, "%s", owner) < 0)
fprint(2, "factotum: setting /dev/hostowner to %q: %r\n",
owner);
close(fd);
}
}
int
attrnamefmt(Fmt *fmt)
{
char *b, buf[1024], *ebuf;
Attr *a;
ebuf = buf+sizeof buf;
b = buf;
strcpy(buf, " ");
for(a=va_arg(fmt->args, Attr*); a; a=a->next){
if(a->name == nil)
continue;
b = seprint(b, ebuf, " %q?", a->name);
}
return fmtstrcpy(fmt, buf+1);
}
void
disablekey(Key *k)
{
Attr *a;
if(sflag) /* not on servers */
return;
for(a=k->attr; a; a=a->next){
if(a->type==AttrNameval && strcmp(a->name, "disabled") == 0)
return;
if(a->next == nil)
break;
}
if(a)
a->next = _mkattr(AttrNameval, "disabled", "by.factotum", nil);
else
k->attr = _mkattr(AttrNameval, "disabled", "by.factotum", nil); /* not reached: always a proto attribute */
}