ref: 8bd7505dc37201cbcb99bf4e6b48d938af64bb5b
dir: /cpu.c/
/* * cpu.c - Make a connection to a cpu server */ #include <u.h> #include <libc.h> #include <auth.h> #include <fcall.h> #include <authsrv.h> #include <libsec.h> #include "args.h" #include "drawterm.h" #define MaxStr 128 static void fatal(int, char*, ...); static void usage(void); static void writestr(int, char*, char*, int); static int readstr(int, char*, int); static char *keyspec = ""; static AuthInfo *p9any(int); static int getkey(Authkey*, char*, char*, char*); static int findkey(Authkey*, char*, char*, char*); static char *host; static int aanfilter; static int norcpu; static int nokbd; static int nogfx; static char *ealgs = "rc4_256 sha1"; /* authentication mechanisms */ static int p9authssl(int); static int p9authtls(int); char *authserver; char *secstore; void exits(char *s) { exit(1); } void usage(void) { fprint(2, "usage: drawterm [-GBOp] [-h host | -c cpuserver] [-a authserver] [-s secstore] [-u user] [-r root]\n"); exits("usage"); } int mountfactotum(void) { int fd; if((fd = dialfactotum()) < 0) return -1; if(sysmount(fd, -1, "/mnt/factotum", MREPL, "") < 0){ fprint(2, "mount factotum: %r\n"); return -1; } if((fd = open("/mnt/factotum/ctl", OREAD)) < 0){ fprint(2, "open /mnt/factotum/ctl: %r\n"); return -1; } close(fd); return 0; } static int startaan(char *host, int fd) { static char script[] = "~ $#netdir 1 || netdir=/net/tcp/clone\n" "netdir=`{basename -d $netdir} || exit\n" "<>$netdir/clone {\n" " netdir=$netdir/`{read} || exit\n" " >[3] $netdir/ctl {\n" " echo -n 'announce *!0' >[1=3]\n" " echo `{cat $netdir/local} || exit\n" " bind '#|' /mnt/aan || exit\n" " exec aan $netdir <>/mnt/aan/data1 >[1=0] >[2]/dev/null &\n" " }\n" "}\n" "<>/mnt/aan/data >[1=0] >[2]/dev/null {\n" " rfork n\n" " fn server {\n" " echo -n aanserver $netdir >/proc/$pid/args\n" " rm -f /env/^'fn#server'\n" " . <{n=`{read} && ! ~ $#n 0 && read -c $n} >[2=1]\n" " }\n" " exec tlssrv -A /bin/rc -c server\n" " exit\n" "}\n"; char buf[128], *p, *na; int n; if(fprint(fd, "%7ld\n%s", strlen(script), script) < 0) fatal(1, "sending aan script"); n = read(fd, buf, sizeof(buf)-1); close(fd); while(n > 0 && buf[n-1] == '\n') n--; if(n <= 0) return -1; buf[n] = 0; if((p = strrchr(buf, '!')) != nil) na = strdup(netmkaddr(host, "tcp", p+1)); else na = strdup(buf); return aanclient(na); } void rcpu(char *host) { static char script[] = "syscall fversion 0 65536 buf 256 >/dev/null >[2=1]\n" "mount -nc /fd/0 /mnt/term || exit\n" "bind -q /mnt/term/dev/cons /dev/cons\n" "if(test -r /mnt/term/dev/kbd){\n" " </dev/cons >/dev/cons >[2=1] aux/kbdfs -dq -m /mnt/term/dev\n" " bind -q /mnt/term/dev/cons /dev/cons\n" "}\n" "</dev/cons >/dev/cons >[2=1] service=cpu exec rc -li\n"; int fd; if((fd = dial(netmkaddr(host, "tcp", "17019"), nil, nil, nil)) < 0) return; /* provide /dev/kbd for kbdfs */ if(!nokbd) bind("#b", "/dev", MAFTER); fd = p9authtls(fd); if(aanfilter){ fd = startaan(host, fd); if(fd < 0) fatal(1, "startaan"); fd = p9authtls(fd); } memset(secstorebuf, 0, sizeof(secstorebuf)); /* forget secstore secrets */ if(fprint(fd, "%7ld\n%s", strlen(script), script) < 0) fatal(1, "sending script"); /* Begin serving the namespace */ exportfs(fd); fatal(1, "starting exportfs"); } void ncpu(char *host) { char buf[MaxStr]; int fd; if((fd = dial(netmkaddr(host, "tcp", "17010"), nil, nil, nil)) < 0) return; /* negotiate authentication mechanism */ strcpy(buf, "p9"); if(ealgs != nil){ strcat(buf, " "); strcat(buf, ealgs); } writestr(fd, buf, "negotiating authentication method", 0); if(readstr(fd, buf, sizeof buf) < 0) fatal(1, "can't negotiate authentication method: %r"); if(*buf) fatal(1, "%s", buf); /* authenticate and encrypt the channel */ fd = p9authssl(fd); /* Tell the remote side where our working directory is */ if(getcwd(buf, sizeof(buf)) == 0) writestr(fd, "NO", "dir", 0); else writestr(fd, buf, "dir", 0); /* * Wait for the other end to execute and start our file service * of /mnt/term */ if(readstr(fd, buf, sizeof(buf)) < 0) fatal(1, "waiting for FS: %r"); if(strncmp("FS", buf, 2) != 0) { print("remote cpu: %s", buf); exits(buf); } if(readstr(fd, buf, sizeof(buf)) < 0) fatal(1, "waiting for remote export: %r"); if(strcmp(buf, "/") != 0){ print("remote cpu: %s", buf); exits(buf); } write(fd, "OK", 2); /* Begin serving the gnot namespace */ exportfs(fd); fatal(1, "starting exportfs"); } void cpumain(int argc, char **argv) { char *s; user = getenv("USER"); authserver = getenv("auth"); host = getenv("cpu"); ARGBEGIN{ case 'a': authserver = EARGF(usage()); break; case 'h': case 'c': host = EARGF(usage()); break; case 'e': ealgs = EARGF(usage()); if(*ealgs == 0 || strcmp(ealgs, "clear") == 0) ealgs = nil; break; case 'r': s = smprint("/root/%s", EARGF(usage())); cleanname(s); if(bind(s, "/root", MREPL) < 0) panic("bind /root: %r"); free(s); break; case 's': secstore = EARGF(usage()); break; case 'k': keyspec = EARGF(usage()); break; case 'u': user = EARGF(usage()); break; case 'G': nogfx = 1; /* wet floor */ case 'B': nokbd = 1; break; case 'O': norcpu = 1; break; case 'p': aanfilter = 1; break; default: usage(); }ARGEND; if(argc != 0) usage(); if(!nogfx) { if(bind("#i", "/dev", MBEFORE) < 0) panic("bind #i: %r"); if(bind("#m", "/dev", MBEFORE) < 0) panic("bind #m: %r"); } if(bind("/root", "/", MAFTER) < 0) panic("bind /root: %r"); if(host == nil) host = readcons("cpu", "cpu", 0); if(user == nil) user = readcons("user", "glenda", 0); if(authserver == nil) authserver = readcons("auth", host, 0); if(mountfactotum() < 0){ if(secstore == nil) secstore = authserver; if(havesecstore(secstore, user)){ s = secstorefetch(secstore, user, nil); if(s){ if(strlen(s) >= sizeof secstorebuf) sysfatal("secstore data too big"); strcpy(secstorebuf, s); } } } if(!norcpu) rcpu(host); ncpu(host); fatal(1, "can't dial %s: %r", host); } void fatal(int syserr, char *fmt, ...) { Fmt f; char *str; va_list arg; fmtstrinit(&f); fmtprint(&f, "cpu: "); va_start(arg, fmt); fmtvprint(&f, fmt, arg); va_end(arg); if(syserr) fmtprint(&f, ": %r"); fmtprint(&f, "\n"); str = fmtstrflush(&f); write(2, str, strlen(str)); exits(str); } void writestr(int fd, char *str, char *thing, int ignore) { int l, n; l = strlen(str); n = write(fd, str, l+1); if(!ignore && n < 0) fatal(1, "writing network: %s", thing); } int readstr(int fd, char *str, int len) { int n; while(len) { n = read(fd, str, 1); if(n < 0) return -1; if(*str == '\0') return 0; str++; len--; } return -1; } static void mksecret(char *t, uchar *f) { sprint(t, "%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux%2.2ux", f[0], f[1], f[2], f[3], f[4], f[5], f[6], f[7], f[8], f[9]); } /* * plan9 authentication followed by rc4 encryption */ static int p9authssl(int fd) { uchar key[16]; uchar digest[SHA1dlen]; char fromclientsecret[21]; char fromserversecret[21]; AuthInfo *ai; ai = p9any(fd); memset(secstorebuf, 0, sizeof(secstorebuf)); /* forget secstore secrets */ if(ai == nil) fatal(1, "can't authenticate"); if(ealgs == nil) return fd; if(ai->nsecret < 8){ fatal(1, "p9authssl: secret too small"); return -1; } memmove(key+4, ai->secret, 8); /* exchange random numbers */ genrandom(key, 4); if(write(fd, key, 4) != 4){ fatal(1, "p9authssl: write random: %r"); return -1; } if(readn(fd, key+12, 4) != 4){ fatal(1, "p9authssl: read random: %r"); return -1; } /* scramble into two secrets */ sha1(key, sizeof(key), digest, nil); mksecret(fromclientsecret, digest); mksecret(fromserversecret, digest+10); /* set up encryption */ fd = pushssl(fd, ealgs, fromclientsecret, fromserversecret, nil); if(fd < 0) fatal(1, "p9authssl: pushssl: %r"); return fd; } /* * p9any authentication followed by tls-psk encryption */ static int p9authtls(int fd) { AuthInfo *ai; TLSconn *conn; ai = p9any(fd); if(ai == nil) fatal(1, "can't authenticate"); conn = mallocz(sizeof(TLSconn), 1); conn->pskID = "p9secret"; conn->psk = ai->secret; conn->psklen = ai->nsecret; fd = tlsClient(fd, conn); if(fd < 0) fatal(1, "tlsClient"); auth_freeAI(ai); free(conn->sessionID); free(conn); return fd; } int authdial(char *net, char *dom) { return dial(netmkaddr(authserver, "tcp", "567"), 0, 0, 0); } static int getastickets(Authkey *key, Ticketreq *tr, uchar *y, char *tbuf, int tbuflen) { int asfd, rv; char *dom; dom = tr->authdom; asfd = authdial(nil, dom); if(asfd < 0) return -1; if(y != nil){ PAKpriv p; rv = -1; tr->type = AuthPAK; if(_asrequest(asfd, tr) != 0 || write(asfd, y, PAKYLEN) != PAKYLEN) goto Out; authpak_new(&p, key, (uchar*)tbuf, 1); if(write(asfd, tbuf, PAKYLEN) != PAKYLEN) goto Out; if(_asrdresp(asfd, tbuf, 2*PAKYLEN) != 2*PAKYLEN) goto Out; memmove(y, tbuf, PAKYLEN); if(authpak_finish(&p, key, (uchar*)tbuf+PAKYLEN)) goto Out; } tr->type = AuthTreq; rv = _asgetticket(asfd, tr, tbuf, tbuflen); Out: close(asfd); return rv; } static int mkservertickets(Authkey *key, Ticketreq *tr, uchar *y, char *tbuf, int tbuflen) { Ticket t; int ret; if(strcmp(tr->authid, tr->hostid) != 0) return -1; memset(&t, 0, sizeof(t)); ret = 0; if(y != nil){ PAKpriv p; t.form = 1; memmove(tbuf, y, PAKYLEN); authpak_new(&p, key, y, 0); authpak_finish(&p, key, (uchar*)tbuf); } memmove(t.chal, tr->chal, CHALLEN); strcpy(t.cuid, tr->uid); strcpy(t.suid, tr->uid); genrandom((uchar*)t.key, sizeof(t.key)); t.num = AuthTc; ret += convT2M(&t, tbuf+ret, tbuflen-ret, key); t.num = AuthTs; ret += convT2M(&t, tbuf+ret, tbuflen-ret, key); memset(&t, 0, sizeof(t)); return ret; } static int gettickets(Authkey *key, Ticketreq *tr, uchar *y, char *tbuf, int tbuflen) { int ret; ret = getastickets(key, tr, y, tbuf, tbuflen); if(ret > 0) return ret; return mkservertickets(key, tr, y, tbuf, tbuflen); } /* * 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; } int askuser(char *params) { Attr *attr; fmtinstall('A', _attrfmt); attr = promptforkey(params); if(attr == nil) sysfatal("no key supplied"); if(sendkey(attr) < 0) sysfatal("sending key to factotum: %r"); return 0; } AuthInfo* p9anyfactotum(int fd, int afd) { return auth_proxy(fd, askuser, "proto=p9any role=client %s", keyspec); } AuthInfo* p9any(int fd) { char buf[1024], buf2[1024], *bbuf, *p, *proto, *dom; uchar crand[2*NONCELEN], cchal[CHALLEN], y[PAKYLEN]; char tbuf[2*MAXTICKETLEN+MAXAUTHENTLEN+PAKYLEN], trbuf[TICKREQLEN+PAKYLEN]; Authkey authkey; Authenticator auth; int afd, i, n, m, v2, dp9ik; Ticketreq tr; Ticket t; AuthInfo *ai; if((afd = open("/mnt/factotum/ctl", ORDWR)) >= 0) return p9anyfactotum(fd, afd); werrstr(""); if(readstr(fd, buf, sizeof buf) < 0) fatal(1, "cannot read p9any negotiation"); bbuf = buf; v2 = 0; if(strncmp(buf, "v.2 ", 4) == 0){ v2 = 1; bbuf += 4; } dp9ik = 0; proto = nil; while(bbuf != nil){ if((p = strchr(bbuf, ' '))) *p++ = 0; if((dom = strchr(bbuf, '@')) == nil) fatal(1, "bad p9any domain"); *dom++ = 0; if(strcmp(bbuf, "p9sk1") == 0 || strcmp(bbuf, "dp9ik") == 0){ proto = bbuf; if(strcmp(proto, "dp9ik") == 0){ dp9ik = 1; break; } } bbuf = p; } if(proto == nil) fatal(1, "server did not offer p9sk1 or dp9ik"); proto = estrdup(proto); sprint(buf2, "%s %s", proto, dom); if(write(fd, buf2, strlen(buf2)+1) != strlen(buf2)+1) fatal(1, "cannot write user/domain choice in p9any"); if(v2){ if(readstr(fd, buf, sizeof buf) < 0) fatal(1, "cannot read OK in p9any"); if(memcmp(buf, "OK\0", 3) != 0) fatal(1, "did not get OK in p9any: got %s", buf); } genrandom(crand, 2*NONCELEN); genrandom(cchal, CHALLEN); if(write(fd, cchal, CHALLEN) != CHALLEN) fatal(1, "cannot write p9sk1 challenge"); n = TICKREQLEN; if(dp9ik) n += PAKYLEN; if(readn(fd, trbuf, n) != n || convM2TR(trbuf, TICKREQLEN, &tr) <= 0) fatal(1, "cannot read ticket request in p9sk1"); if(!findkey(&authkey, user, tr.authdom, proto)){ again: if(!getkey(&authkey, user, tr.authdom, proto)) fatal(1, "no password"); } strecpy(tr.hostid, tr.hostid+sizeof tr.hostid, user); strecpy(tr.uid, tr.uid+sizeof tr.uid, user); if(dp9ik){ memmove(y, trbuf+TICKREQLEN, PAKYLEN); n = gettickets(&authkey, &tr, y, tbuf, sizeof(tbuf)); } else { n = gettickets(&authkey, &tr, nil, tbuf, sizeof(tbuf)); } if(n <= 0) fatal(1, "cannot get auth tickets in p9sk1"); m = convM2T(tbuf, n, &t, &authkey); if(m <= 0 || t.num != AuthTc){ print("?password mismatch with auth server\n"); goto again; } n -= m; memmove(tbuf, tbuf+m, n); if(dp9ik && write(fd, y, PAKYLEN) != PAKYLEN) fatal(1, "cannot send authpak public key back"); auth.num = AuthAc; memmove(auth.rand, crand, NONCELEN); memmove(auth.chal, tr.chal, CHALLEN); m = convA2M(&auth, tbuf+n, sizeof(tbuf)-n, &t); n += m; if(write(fd, tbuf, n) != n) fatal(1, "cannot send ticket and authenticator back"); if((n=readn(fd, tbuf, m)) != m || memcmp(tbuf, "cpu:", 4) == 0){ if(n <= 4) fatal(1, "cannot read authenticator"); /* * didn't send back authenticator: * sent back fatal error message. */ memmove(buf, tbuf, n); i = readn(fd, buf+n, sizeof buf-n-1); if(i > 0) n += i; buf[n] = 0; werrstr(""); fatal(0, "server says: %s", buf); } if(convM2A(tbuf, n, &auth, &t) <= 0 || auth.num != AuthAs || tsmemcmp(auth.chal, cchal, CHALLEN) != 0){ print("?you and auth server agree about password.\n"); print("?server is confused.\n"); fatal(0, "server lies got %llux want %llux", *(vlong*)auth.chal, *(vlong*)cchal); } memmove(crand+NONCELEN, auth.rand, NONCELEN); // print("i am %s there.\n", t.suid); ai = mallocz(sizeof(AuthInfo), 1); ai->suid = estrdup(t.suid); ai->cuid = estrdup(t.cuid); if(dp9ik){ static char info[] = "Plan 9 session secret"; ai->nsecret = 256; ai->secret = mallocz(ai->nsecret, 1); hkdf_x( crand, 2*NONCELEN, (uchar*)info, sizeof(info)-1, (uchar*)t.key, NONCELEN, ai->secret, ai->nsecret, hmac_sha2_256, SHA2_256dlen); } else { ai->nsecret = 8; ai->secret = mallocz(ai->nsecret, 1); des56to64((uchar*)t.key, ai->secret); } memset(&t, 0, sizeof(t)); memset(&auth, 0, sizeof(auth)); memset(&authkey, 0, sizeof(authkey)); memset(cchal, 0, sizeof(cchal)); memset(crand, 0, sizeof(crand)); free(proto); return ai; } static int unhex(char c) { if('0' <= c && c <= '9') return c-'0'; if('a' <= c && c <= 'f') return c-'a'+10; if('A' <= c && c <= 'F') return c-'A'+10; abort(); return -1; } static int hexparse(char *hex, uchar *dat, int ndat) { int i; if(strlen(hex) != 2*ndat) return -1; if(hex[strspn(hex, "0123456789abcdefABCDEF")] != '\0') return -1; for(i=0; i<ndat; i++) dat[i] = (unhex(hex[2*i])<<4)|unhex(hex[2*i+1]); return 0; } static int findkey(Authkey *key, char *user, char *dom, char *proto) { char buf[1024], *f[50], *p, *ep, *nextp, *hex, *pass, *id, *role; int nf, haveproto, havedom, i; for(p=secstorebuf; *p; p=nextp){ nextp = strchr(p, '\n'); if(nextp == nil){ ep = p+strlen(p); nextp = ""; }else{ ep = nextp++; } if(ep-p >= sizeof buf){ print("warning: skipping long line in secstore factotum file\n"); continue; } memmove(buf, p, ep-p); buf[ep-p] = 0; nf = tokenize(buf, f, nelem(f)); if(nf == 0 || strcmp(f[0], "key") != 0) continue; id = pass = hex = role = nil; havedom = haveproto = 0; for(i=1; i<nf; i++){ if(strncmp(f[i], "user=", 5) == 0) id = f[i]+5; if(strncmp(f[i], "!password=", 10) == 0) pass = f[i]+10; if(strncmp(f[i], "!hex=", 5) == 0) hex = f[i]+5; if(strncmp(f[i], "role=", 5) == 0) role = f[i]+5; if(strncmp(f[i], "dom=", 4) == 0 && strcmp(f[i]+4, dom) == 0) havedom = 1; if(strncmp(f[i], "proto=", 6) == 0 && strcmp(f[i]+6, proto) == 0) haveproto = 1; } if(!haveproto || !havedom) continue; if(role != nil && strcmp(role, "client") != 0) continue; if(id == nil || strcmp(user, id) != 0) continue; if(pass == nil && hex == nil) continue; if(hex != nil){ memset(key, 0, sizeof(*key)); if(strcmp(proto, "dp9ik") == 0) { if(hexparse(hex, key->aes, AESKEYLEN) != 0) continue; } else { if(hexparse(hex, (uchar*)key->des, DESKEYLEN) != 0) continue; } } else { passtokey(key, pass); } if(strcmp(proto, "dp9ik") == 0) authpak_hash(key, user); memset(buf, 0, sizeof buf); return 1; } memset(buf, 0, sizeof buf); return 0; } static int getkey(Authkey *key, char *user, char *dom, char *proto) { char buf[1024], *pass; snprint(buf, sizeof buf, "%s@%s %s password", user, dom, proto); pass = readcons(buf, nil, 1); memset(buf, 0, sizeof buf); if(pass != nil){ snprint(secstorebuf, sizeof(secstorebuf), "key proto=%q dom=%q user=%q !password=%q\n", proto, dom, user, pass); memset(pass, 0, strlen(pass)); free(pass); return findkey(key, user, dom, proto); } return 0; }