diff options
Diffstat (limited to 'appl/cmd/auth/logind.b')
| -rw-r--r-- | appl/cmd/auth/logind.b | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/appl/cmd/auth/logind.b b/appl/cmd/auth/logind.b new file mode 100644 index 00000000..f9d14616 --- /dev/null +++ b/appl/cmd/auth/logind.b @@ -0,0 +1,244 @@ +implement Logind; + +# +# certification service (signer) +# + +include "sys.m"; + sys: Sys; + +include "draw.m"; + +include "keyring.m"; + kr: Keyring; + IPint: import kr; + +include "security.m"; + ssl: SSL; + +include "daytime.m"; + daytime: Daytime; + +Logind: module +{ + init: fn(ctxt: ref Draw->Context, argv: list of string); +}; + +TimeLimit: con 5*60*1000; # five minutes +keydb := "/mnt/keys"; + +stderr: ref Sys->FD; + +init(nil: ref Draw->Context, nil: list of string) +{ + sys = load Sys Sys->PATH; + stderr = sys->open("/dev/cons", sys->OWRITE); + + kr = load Keyring Keyring->PATH; + + ssl = load SSL SSL->PATH; + if(ssl == nil) + nomod(SSL->PATH); + + daytime = load Daytime Daytime->PATH; + if(daytime == nil) + nomod(Daytime->PATH); + + (err, c) := ssl->connect(sys->fildes(0)); + if(c == nil) + fatal("pushing ssl: " + err); + + # impose time out to ensure dead network connections recovered well before TCP/IP's long time out + + grpid := sys->pctl(Sys->NEWPGRP,nil); + pidc := chan of int; + spawn stalker(pidc, grpid); + tpid := <-pidc; + err = dologin(c); + if(err != nil){ + sys->fprint(stderr, "logind: %s\n", err); + kr->puterror(c.dfd, err); + } + kill(tpid, "kill"); +} + +dologin(c: ref Sys->Connection): string +{ + ivec: array of byte; + + (info, err) := signerkey("/keydb/signerkey"); + if(info == nil) + return "can't read signer's own key: "+err; + + # get user name; ack + s: string; + (s, err) = kr->getstring(c.dfd); + if(err != nil) + return err; + name := s; + kr->putstring(c.dfd, name); + + # get initialization vector + (ivec, err) = kr->getbytearray(c.dfd); + if(err != nil) + return "can't get initialization vector: "+err; + + # lookup password + pw := getsecret(s); + if(pw == nil) + return sys->sprint("no password entry for %s: %r", s); + if(len pw < Keyring->SHA1dlen) + return "bad password for "+s+": not SHA1 hashed?"; + userexp := getexpiry(s); + if(userexp < 0) + return sys->sprint("expiry time for %s: %r", s); + + # generate our random diffie hellman part + bits := info.p.bits(); + r0 := kr->IPint.random(bits/4, bits); + + # generate alpha0 = alpha**r0 mod p + alphar0 := info.alpha.expmod(r0, info.p); + + # start encrypting + pwbuf := array[8] of byte; + for(i := 0; i < 8; i++) + pwbuf[i] = pw[i] ^ pw[8+i]; + for(i = 0; i < 4; i++) + pwbuf[i] ^= pw[16+i]; + for(i = 0; i < 8; i++) + pwbuf[i] ^= ivec[i]; + err = ssl->secret(c, pwbuf, pwbuf); + if(err != nil) + return "can't set ssl secret: "+err; + + if(sys->fprint(c.cfd, "alg rc4") < 0) + return sys->sprint("can't push alg rc4: %r"); + + # send P(alpha**r0 mod p) + if(kr->putstring(c.dfd, alphar0.iptob64()) < 0) + return sys->sprint("can't send (alpha**r0 mod p): %r"); + + # stop encrypting + if(sys->fprint(c.cfd, "alg clear") < 0) + return sys->sprint("can't clear alg: %r"); + + # send alpha, p + if(kr->putstring(c.dfd, info.alpha.iptob64()) < 0 || + kr->putstring(c.dfd, info.p.iptob64()) < 0) + return sys->sprint("can't send alpha, p: %r"); + + # get alpha**r1 mod p + (s, err) = kr->getstring(c.dfd); + if(err != nil) + return "can't get alpha**r1 mod p:"+err; + alphar1 := kr->IPint.b64toip(s); + + # compute alpha**(r0*r1) mod p + alphar0r1 := alphar1.expmod(r0, info.p); + + # turn on digesting + secret := alphar0r1.iptobytes(); + err = ssl->secret(c, secret, secret); + if(err != nil) + return "can't set digest secret: "+err; + if(sys->fprint(c.cfd, "alg sha1") < 0) + return sys->sprint("can't push alg sha1: %r"); + + # send our public key + if(kr->putstring(c.dfd, kr->pktostr(kr->sktopk(info.mysk))) < 0) + return sys->sprint("can't send signer's public key: %r"); + + # get his public key + (s, err) = kr->getstring(c.dfd); + if(err != nil) + return "client public key: "+err; + hisPKbuf := array of byte s; + hisPK := kr->strtopk(s); + if(hisPK.owner != name) + return "pk name doesn't match user name"; + + # sign and return + state := kr->sha1(hisPKbuf, len hisPKbuf, nil, nil); + cert := kr->sign(info.mysk, userexp, state, "sha1"); + + if(kr->putstring(c.dfd, kr->certtostr(cert)) < 0) + return sys->sprint("can't send certificate: %r"); + + return nil; +} + +nomod(mod: string) +{ + fatal(sys->sprint("can't load %s: %r",mod)); +} + +fatal(msg: string) +{ + sys->fprint(stderr, "logind: %s\n", msg); + exit; +} + +signerkey(filename: string): (ref Keyring->Authinfo, string) +{ + + info := kr->readauthinfo(filename); + if(info == nil) + return (nil, sys->sprint("readauthinfo %r")); + + # validate signer key + now := daytime->now(); + if(info.cert.exp != 0 && info.cert.exp < now) + return (nil, sys->sprint("signer key expired")); + + return (info, nil); +} + +getsecret(id: string): array of byte +{ + fd := sys->open(sys->sprint("%s/%s/secret", keydb, id), Sys->OREAD); + if(fd == nil) + return nil; + (ok, d) := sys->fstat(fd); + if(ok < 0) + return nil; + a := array[int d.length] of byte; + n := sys->read(fd, a, len a); + if(n < 0) + return nil; + return a[0:n]; +} + +getexpiry(id: string): int +{ + fd := sys->open(sys->sprint("%s/%s/expire", keydb, id), Sys->OREAD); + if(fd == nil) + return -1; + a := array[Sys->NAMEMAX] of byte; + n := sys->read(fd, a, len a); + if(n < 0) + return -1; + s := string a[0:n]; + if(s == "never") + return 0; + if(s == "expired"){ + sys->werrstr(sys->sprint("entry for %s expired", id)); + return -1; + } + return int s; +} + +stalker(pidc: chan of int, killpid: int) +{ + pidc <-= sys->pctl(0, nil); + sys->sleep(TimeLimit); + sys->fprint(stderr, "logind: login timed out\n"); + kill(killpid, "killgrp"); +} + +kill(pid: int, how: string) +{ + fd := sys->open("#p/" + string pid + "/ctl", Sys->OWRITE); + if(fd == nil || sys->fprint(fd, "%s", how) < 0) + sys->fprint(stderr, "logind: can't %s %d: %r\n", how, pid); +} |