ref: da7d6df6faf18e289fe0f3f61524dcc7fddeef18
dir: /appl/lib/factotum.b/
implement Factotum;
#
# client interface to factotum
#
# this is a near transliteration of Plan 9 code, subject to the Lucent Public License 1.02
#
include "sys.m";
sys: Sys;
include "string.m";
include "factotum.m";
debug := 0;
init()
{
sys = load Sys Sys->PATH;
}
setdebug(i: int)
{
debug = i;
}
getaia(a: array of byte, n: int): (int, array of byte)
{
if(len a - n < 2)
return (-1, nil);
c := (int a[n+1]<<8) | int a[n+0];
n += 2;
if(len a - n < c)
return (-1, nil);
b := array[c] of byte; # could avoid copy if known not to alias
b[0:] = a[n: n+c];
return (n+c, b);
}
getais(a: array of byte, n: int): (int, string)
{
(n, a) = getaia(a, n);
return (n, string a);
}
Authinfo.unpack(a: array of byte): (int, ref Authinfo)
{
ai := ref Authinfo;
n: int;
(n, ai.cuid) = getais(a, 0);
(n, ai.suid) = getais(a, n);
(n, ai.cap) = getais(a, n);
(n, ai.secret) = getaia(a, n);
if(n < 0)
return (-1, nil);
return (n, ai);
}
open(): ref Sys->FD
{
return sys->open("/mnt/factotum/rpc", Sys->ORDWR);
}
mount(fd: ref Sys->FD, mnt: string, flags: int, aname: string, keyspec: string): (int, ref Authinfo)
{
ai: ref Authinfo;
afd := sys->fauth(fd, aname);
if(debug && afd == nil){
sys->print("fauth %s: %r\n", aname);
return (-1, nil);
}
if(afd != nil){
ai = proxy(afd, open(), "proto=p9any role=client "+keyspec);
if(debug && ai == nil){
sys->print("proxy failed: %r\n");
return (-1, nil);
}
}
return (sys->mount(fd, afd, mnt, flags, aname), ai);
}
dump(a: array of byte): string
{
s := sys->sprint("[%d]", len a);
for(i := 0; i < len a; i++){
c := int a[i];
if(c >= ' ' && c <= 16r7E)
s += sys->sprint("%c", c);
else
s += sys->sprint("\\x%.2ux", c);
}
return s;
}
verbof(buf: array of byte): (string, array of byte)
{
n := len buf;
for(i:=0; i<n && buf[i] != byte ' '; i++)
;
s := string buf[0:i];
if(i < n)
i++;
buf = buf[i:];
case s {
"ok" or "error" or "done" or "phase" or
"protocol" or "needkey" or "toosmall" or "internal" =>
return (s, buf);
* =>
sys->werrstr(sys->sprint("malformed rpc response: %q", s));
return ("rpc failure", buf);
}
}
dorpc(fd: ref Sys->FD, verb: string, val: array of byte): (string, array of byte)
{
(o, a) := rpc(fd, verb, val);
if(o != "needkey" && o != "badkey")
return (o, a);
return ("no key", a); # don't know how to get key
}
rpc(afd: ref Sys->FD, verb: string, a: array of byte): (string, array of byte)
{
va := array of byte verb;
l := len va;
na := len a;
if(na+l+1 > AuthRpcMax){
sys->werrstr("rpc too big");
return ("toobig", nil);
}
buf := array[na+l+1] of byte;
buf[0:] = va;
buf[l] = byte ' ';
buf[l+1:] = a;
if(debug)
sys->print("rpc: ->%s %s\n", verb, dump(a));
if((n:=sys->write(afd, buf, len buf)) != len buf){
if(n >= 0)
sys->werrstr("rpc short write");
return ("rpc failure", nil);
}
buf = array[AuthRpcMax] of byte;
if((n=sys->read(afd, buf, len buf)) < 0){
if(debug)
sys->print("<- (readerr) %r\n");
return ("rpc failure", nil);
}
if(n < len buf)
buf[n] = byte 0;
buf = buf[0:n];
#
# Set error string for good default behavior.
#
s: string;
(t, r) := verbof(buf);
if(debug)
sys->print("<- %s %#q\n", t, dump(r));
case t {
"ok" or
"rpc failure" =>
; # don't touch
"error" =>
if(len r == 0)
s = "unspecified rpc error";
else
s = sys->sprint("%s", string r);
"needkey" =>
s = sys->sprint("needkey %s", string r);
"badkey" =>
(nf, flds) := sys->tokenize(string r, "\n");
if(nf < 2)
s = sys->sprint("badkey %q", string r);
else
s = sys->sprint("badkey %q", hd tl flds);
break;
"phase" =>
s = sys->sprint("phase error: %q", string r);
* =>
s = sys->sprint("unknown rpc type %q (bug in rpc.c)", t);
}
if(s != nil)
sys->werrstr(s);
return (t, r);
}
Authinfo.read(fd: ref Sys->FD): ref Authinfo
{
(o, a) := rpc(fd, "authinfo", nil);
if(o != "ok")
return nil;
(n, ai) := Authinfo.unpack(a);
if(n <= 0)
sys->werrstr("bad auth info from factotum");
return ai;
}
proxy(fd: ref Sys->FD, afd: ref Sys->FD, params: string): ref Authinfo
{
readc := chan of (array of byte, chan of (int, string));
writec := chan of (array of byte, chan of (int, string));
donec := chan of (ref Authinfo, string);
spawn genproxy(readc, writec, donec, afd, params);
for(;;)alt{
(buf, reply) := <-readc =>
n := sys->read(fd, buf, len buf);
if(n == -1)
reply <-= (-1, sys->sprint("%r"));
else
reply <-= (n, nil);
(buf, reply) := <-writec =>
n := sys->write(fd, buf, len buf);
if(n == -1)
reply <-= (-1, sys->sprint("%r"));
else
reply <-= (n, nil);
(authinfo, err) := <-donec =>
if(authinfo == nil)
sys->werrstr(err);
return authinfo;
}
}
#
# do what factotum says
#
genproxy(
readc: chan of (array of byte, chan of (int, string)),
writec: chan of (array of byte, chan of (int, string)),
donec: chan of (ref Authinfo, string),
afd: ref Sys->FD,
params: string)
{
if(afd == nil){
donec <-= (nil, "no authentication fd");
return;
}
pa := array of byte params;
(o, a) := dorpc(afd, "start", pa);
if(o != "ok"){
donec <-= (nil, sys->sprint("proxy start: %r"));
return;
}
ai: ref Authinfo;
err: string;
done:
for(;;){
(o, a) = dorpc(afd, "read", nil);
case o {
"done" =>
if(len a > 0 && a[0] == byte 'h' && string a == "haveai")
ai = Authinfo.read(afd);
else
ai = ref Authinfo; # auth succeeded but empty authinfo
break done;
"ok" =>
writec <-= (a[0:len a], reply := chan of (int, string));
(n, e) := <-reply;
if(n != len a){
err = "proxy write fd: "+e;
break done;
}
"phase" =>
buf := array[AuthRpcMax] of {* => byte 0};
n := 0;
for(;;){
(o, a) = dorpc(afd, "write", buf[0:n]);
if(o != "toosmall")
break;
c := int string a;
if(c > AuthRpcMax)
break;
readc <-= (buf[n:c], reply := chan of (int, string));
(m, e) := <-reply;
if(m <= 0){
err = e;
if(m == 0)
err = sys->sprint("proxy short read");
break done;
}
n += m;
}
if(o != "ok"){
err = sys->sprint("proxy rpc write: %r");
break done;
}
* =>
err = sys->sprint("proxy rpc: %r");
break done;
}
}
donec <-= (ai, err);
}
#
# insecure passwords, role=client
#
getuserpasswd(keyspec: string): (string, string)
{
str := load String String->PATH;
if(str == nil)
return (nil, nil);
fd := open();
if(fd == nil)
return (nil, nil);
if(((o, a) := dorpc(fd, "start", array of byte keyspec)).t0 != "ok" ||
((o, a) = dorpc(fd, "read", nil)).t0 != "ok"){
sys->werrstr("factotum: "+o);
return (nil, nil);
}
flds := str->unquoted(string a);
if(len flds != 2){
sys->werrstr("odd response from factotum");
return (nil, nil);
}
return (hd flds, hd tl flds);
}
#
# challenge/response, role=server
#
challenge(keyspec: string): ref Challenge
{
c := ref Challenge;
if((c.afd = open()) == nil)
return nil;
if(rpc(c.afd, "start", array of byte keyspec).t0 != "ok")
return nil;
(w, val) := rpc(c.afd, "read", nil);
if(w != "ok")
return nil;
c.chal = string val;
return c;
}
response(c: ref Challenge, resp: string): ref Authinfo
{
if(c.afd == nil){
sys->werrstr("auth_response: connection not open");
return nil;
}
if(resp == nil){
sys->werrstr("auth_response: nil response");
return nil;
}
if(c.user != nil){
if(rpc(c.afd, "write", array of byte c.user).t0 != "ok"){
# we're out of phase with factotum; give up
c.afd = nil;
return nil;
}
}
if(rpc(c.afd, "write", array of byte resp).t0 != "ok"){
# don't close the connection; we might try again
return nil;
}
(w, val) := rpc(c.afd, "read", nil);
if(w != "done"){
sys->werrstr(sys->sprint("unexpected factotum reply: %q %q", w, string val));
c.afd = nil;
return nil;
}
ai := Authinfo.read(c.afd);
c.afd = nil;
return ai;
}
#
# challenge/response, role=client
#
respond(chal: string, keyspec: string): (string, string)
{
if((afd := open()) == nil)
return (nil, nil);
if(dorpc(afd, "start", array of byte keyspec).t0 != "ok" ||
dorpc(afd, "write", array of byte chal).t0 != "ok")
return (nil, nil);
(o, resp) := dorpc(afd, "read", nil);
if(o != "ok")
return (nil, nil);
return (string resp, findattrval(rpcattrs(afd), "user"));
}
rpcattrs(afd: ref Sys->FD): list of ref Attr
{
(o, a) := rpc(afd, "attr", nil);
if(o != "ok")
return nil;
return parseattrs(string a);
}
#
# attributes
#
parseattrs(s: string): list of ref Attr
{
str := load String String->PATH;
fld := str->unquoted(s);
rfld := fld;
for(fld = nil; rfld != nil; rfld = tl rfld)
fld = (hd rfld) :: fld;
attrs: list of ref Attr;
for(; fld != nil; fld = tl fld){
n := hd fld;
a := "";
tag := Aattr;
for(i:=0; i<len n; i++)
if(n[i] == '='){
a = n[i+1:];
n = n[0:i];
tag = Aval;
}
if(len n == 0)
continue;
if(tag == Aattr && len n > 1 && n[len n-1] == '?'){
tag = Aquery;
n = n[0:len n-1];
}
attrs = ref Attr(tag, n, a) :: attrs;
}
# TO DO: eliminate answered queries
return attrs;
}
Attr.text(a: self ref Attr): string
{
case a.tag {
Aattr =>
return a.name;
Aval =>
return sys->sprint("%q=%q", a.name, a.val);
Aquery =>
return sys->sprint("%q?", a.name);
* =>
return "??";
}
}
attrtext(attrs: list of ref Attr): string
{
s := "";
for(; attrs != nil; attrs = tl attrs){
if(s != nil)
s[len s] = ' ';
s += (hd attrs).text();
}
return s;
}
findattr(attrs: list of ref Attr, n: string): ref Attr
{
for(; attrs != nil; attrs = tl attrs)
if((a := hd attrs).tag != Aquery && a.name == n)
return a;
return nil;
}
findattrval(attrs: list of ref Attr, n: string): string
{
if((a := findattr(attrs, n)) != nil)
return a.val;
return nil;
}
delattr(l: list of ref Attr, n: string): list of ref Attr
{
rl: list of ref Attr;
for(; l != nil; l = tl l)
if((hd l).name != n)
rl = hd l :: rl;
return rev(rl);
}
copyattrs(l: list of ref Attr): list of ref Attr
{
rl: list of ref Attr;
for(; l != nil; l = tl l)
rl = hd l :: rl;
return rev(rl);
}
takeattrs(l: list of ref Attr, names: list of string): list of ref Attr
{
rl: list of ref Attr;
for(; l != nil; l = tl l){
n := (hd l).name;
for(nl := names; nl != nil; nl = tl nl)
if((hd nl) == n){
rl = hd l :: rl;
break;
}
}
return rev(rl);
}
publicattrs(l: list of ref Attr): list of ref Attr
{
rl: list of ref Attr;
for(; l != nil; l = tl l){
a := hd l;
if(a.tag != Aquery || a.val == nil)
rl = a :: rl;
}
return rev(rl);
}
rev[T](l: list of T): list of T
{
rl: list of T;
for(; l != nil; l = tl l)
rl = hd l :: rl;
return rl;
}