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implement Authproto;
# currently includes p9sk1
include "sys.m";
sys: Sys;
Rread, Rwrite: import Sys;
include "draw.m";
include "keyring.m";
kr: Keyring;
include "auth9.m";
auth9: Auth9;
ANAMELEN, AERRLEN, DOMLEN, DESKEYLEN, CHALLEN, SECRETLEN: import Auth9;
TICKREQLEN, TICKETLEN, AUTHENTLEN: import Auth9;
Ticketreq, Ticket, Authenticator: import auth9;
include "../authio.m";
authio: Authio;
Aattr, Aval, Aquery: import Authio;
Attr, IO, Key, Authinfo: import authio;
netmkaddr, eqbytes, memrandom: import authio;
include "encoding.m";
base16: Encoding;
Debug: con 0;
# init, addkey, closekey, write, read, close, keyprompt
init(f: Authio): string
{
authio = f;
sys = load Sys Sys->PATH;
kr = load Keyring Keyring->PATH;
auth9 = load Auth9 Auth9->PATH;
auth9->init();
base16 = load Encoding Encoding->BASE16PATH;
return nil;
}
version := 1;
interaction(attrs: list of ref Attr, io: ref IO): string
{
return p9any(io);
}
p9any(io: ref IO): string
{
while((buf := io.read()) == nil || (n := len buf) == 0 || buf[n-1] != byte 0)
io.toosmall(2048);
s := string buf[0:n-1];
if(Debug)
sys->print("s: %q\n", s);
(nil, flds) := sys->tokenize(s, " \t");
if(flds != nil && len hd flds >= 2 && (hd flds)[0:2] == "v."){
if(hd flds == "v.2"){
version = 2;
flds = tl flds;
if(Debug)
sys->print("version 2\n");
}else
return "p9any: unknown version";
}
doms: list of string;
for(; flds != nil; flds = tl flds){
(nf, subf) := sys->tokenize(hd flds, "@");
if(nf == 2 && hd subf == "p9sk1")
doms = hd tl subf :: doms;
}
if(doms == nil)
return "p9any: unsupported protocol";
if(Debug){
for(l := doms; l != nil; l = tl l)
sys->print("dom: %q\n", hd l);
}
r := array of byte ("p9sk1 "+hd doms);
buf[0:] = r;
buf[len r] = byte 0;
io.write(buf, len r + 1);
if(version == 2){
b := io.readn(3);
if(b == nil || b[0] != byte 'O' || b[1] != byte 'K' || b[2] != byte 0)
return "p9any: AS protocol botch: not OK";
if(Debug)
sys->print("OK\n");
}
return p9sk1client(io, hd doms);
}
#p9sk1:
# C->S: nonce-C
# S->C: nonce-S, uid-S, domain-S
# C->A: nonce-S, uid-S, domain-S, uid-C, factotum-C
# A->C: Kc{nonce-S, uid-C, uid-S, Kn}, Ks{nonce-S, uid-C, uid-S, K-n}
# C->S: Ks{nonce-S, uid-C, uid-S, K-n}, Kn{nonce-S, counter}
# S->C: Kn{nonce-C, counter}
#asserts that uid-S and uid-C share new secret Kn
#increment the counter to reuse the ticket.
p9sk1client(io: ref IO, udom: string): string
{
# C->S: nonce-C
cchal := array[CHALLEN] of byte;
memrandom(cchal, CHALLEN);
if(io.write(cchal, len cchal) != len cchal)
return sys->sprint("p9sk1: can't write cchal: %r");
# S->C: nonce-S, uid-S, domain-S
trbuf := io.readn(TICKREQLEN);
if(trbuf == nil)
return sys->sprint("p9sk1: can't read ticketreq: %r");
(nil, tr) := Ticketreq.unpack(trbuf);
if(tr == nil)
return "p9sk1: can't unpack ticket request";
if(Debug)
sys->print("ticketreq: type=%d authid=%q authdom=%q chal= hostid=%q uid=%q\n",
tr.rtype, tr.authid, tr.authdom, tr.hostid, tr.uid);
(mykey, diag) := io.findkey(nil, sys->sprint("dom=%q proto=p9sk1 user? !password?", udom));
if(mykey == nil)
return "can't find key: "+diag;
ukey: array of byte;
if((a := authio->lookattrval(mykey.secrets, "!hex")) != nil){
ukey = base16->dec(a);
if(len ukey != DESKEYLEN)
return "p9sk1: invalid !hex key";
}else if((a = authio->lookattrval(mykey.secrets, "!password")) != nil)
ukey = auth9->passtokey(a);
else
return "no !password (or !hex) in key";
# A->C: Kc{nonce-S, uid-C, uid-S, Kn}, Ks{nonce-S, uid-C, uid-S, K-n}
user := authio->lookattrval(mykey.attrs, "user");
if(user == nil)
user = authio->user(); # shouldn't happen
tr.rtype = Auth9->AuthTreq;
tr.hostid = user;
tr.uid = tr.hostid; # not speaking for anyone else
(tick, serverbits) := getastickets(tr, ukey);
if(tick == nil)
return sys->sprint("p9sk1: getasticket failed: %r");
if(tick.num != Auth9->AuthTc)
return "p9sk1: getasticket: failed: wrong key?";
if(Debug)
sys->print("ticket: num=%d chal= cuid=%q suid=%q key=\n", tick.num, tick.cuid, tick.suid);
# C->S: Ks{nonce-S, uid-C, uid-S, K-n}, Kn{nonce-S, counter}
ar := ref Authenticator;
ar.num = Auth9->AuthAc;
ar.chal = tick.chal;
ar.id = 0;
obuf := array[TICKETLEN+AUTHENTLEN] of byte;
obuf[0:] = serverbits;
obuf[TICKETLEN:] = ar.pack(tick.key);
if(io.write(obuf, len obuf) != len obuf)
return "p9sk1: error writing authenticator: %r";
# S->C: Kn{nonce-C, counter}
sbuf := io.readn(AUTHENTLEN);
if(sbuf == nil)
return sys->sprint("p9sk1: can't read server's authenticator: %r");
(nil, ar) = Authenticator.unpack(sbuf, tick.key);
if(ar.num != Auth9->AuthAs || !eqbytes(ar.chal, cchal) || ar.id != 0)
return "invalid authenticator from server";
ai := ref Authinfo(tick.cuid, tick.suid, nil, auth9->des56to64(tick.key));
io.done(ai);
return nil;
}
getastickets(tr: ref Ticketreq, key: array of byte): (ref Ticket, array of byte)
{
afd := authdial(nil, tr.authdom);
if(afd == nil)
return (nil, nil);
return auth9->_asgetticket(afd, tr, key);
}
#
# where to put the following functions?
#
csgetvalue(netroot: string, keytag: string, keyval: string, needtag: string): string
{
cs := "/net/cs";
if(netroot != nil)
cs = netroot+"/cs";
fd := sys->open(cs, Sys->ORDWR); # TO DO: choice of root
if(fd == nil)
return nil;
if(sys->fprint(fd, "!%s=%s %s=*", keytag, keyval, needtag) < 0)
return nil;
sys->seek(fd, big 0, 0);
buf := array[1024] of byte;
while((n := sys->read(fd, buf, len buf)) > 0){
al := authio->parseline(string buf[0:n]); # assume the conventions match factotum's
for(; al != nil; al = tl al)
if((hd al).name == needtag)
return (hd al).val;
}
return nil;
}
authdial(netroot: string, dom: string): ref Sys->FD
{
p: string;
if(dom != nil){
# look up an auth server in an authentication domain
p = csgetvalue(netroot, "authdom", dom, "auth");
# if that didn't work, just try the IP domain
if(p == nil)
p = csgetvalue(netroot, "dom", dom, "auth");
if(p == nil)
p = "$auth"; # temporary ...
if(p == nil){
sys->werrstr("no auth server found for "+dom);
return nil;
}
}else
p = "$auth"; # look for one relative to my machine
(nil, conn) := sys->dial(netmkaddr(p, netroot, "ticket"), nil);
return conn.dfd;
}
keycheck(nil: ref Authio->Key): string
{
return nil;
}
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