ref: 396f8f369db25a0d6b0120ea08ecc84d089b8202
dir: /cpu.c/
/*
* cpu.c - Make a connection to a cpu server
*/
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <netinet/in.h>
#include <gnutls/gnutls.h>
#include <u.h>
#include <args.h>
#include <libc.h>
#include <auth.h>
#include <authsrv.h>
#include <libsec.h>
#define MaxStr 128
static void usage(void);
static int readstr(int, char*, int);
static AuthInfo *p9any(int);
static int getkey(Authkey*, char*, char*, char*, char*);
static int p9authtls(int);
static char *host;
char *argv0;
char *authserver;
char *secstore;
char *user, *pass;
char secstorebuf[65536];
char *geometry;
gnutls_session_t session;
void errstr(char *s){}
int
unix_dial(char *host, char *port)
{
int fd;
struct sockaddr_in server;
struct hostent *he;
struct in_addr **addr_list;
he = gethostbyname(host);
if(he == nil){
sysfatal("could not resolve %s", host);
}
fd = socket(AF_INET, SOCK_STREAM, 0);
addr_list = (struct in_addr **) he->h_addr_list;
server.sin_addr.s_addr = inet_addr(inet_ntoa(*addr_list[0]));
server.sin_family = AF_INET;
server.sin_port = htons(atoi(port));
if(connect(fd, (struct sockaddr*)&server, sizeof(server)) < 0)
return -1;
return fd;
}
char*
estrdup(char *s)
{
s = strdup(s);
if(s == nil)
sysfatal("out of memory");
return s;
}
typedef size_t (*iofunc)(int, void*, size_t);
size_t tls_send(int f, void *b, size_t n) { return gnutls_record_send(session, b, n); }
size_t tls_recv(int f, void *b, size_t n) { return gnutls_record_recv(session, b, n); }
size_t s_send(int f, void *b, size_t n) { return write(f, b, n); }
size_t s_recv(int f, void *b, size_t n) { return read(f, b, n); }
void
xfer(int from, int to, iofunc recvf, iofunc sendf)
{
char buf[12*1024];
size_t n;
while((n = recvf(from, buf, sizeof buf)) > 0){
if(sendf(to, buf, n) < 0)
break;
}
}
void
usage(void)
{
fprint(2, "Usage: %s [-f] [ -u user ] [ -h host ] [ -a authserver ] -p port cmd...\n", argv0);
exits("usage");
}
int
main(int argc, char **argv)
{
int fd, res;
char *cmd;
char buf[1024];
size_t n;
char *port;
int pin[2];
int pout[2];
int infd, outfd;
pid_t execc, xferc;
int consin, consout, consflag;
execc = xferc = 0;
consflag = 0;
infd = 0;
outfd = 1;
user = getenv("USER");
host = getenv("CPU");
authserver = getenv("AUTH");
pass = getenv("PASS");
port = nil;
ARGBEGIN {
case 'u': user = EARGF(usage()); break;
case 'h': host = EARGF(usage()); break;
case 'a': authserver = EARGF(usage()); break;
case 'p': port = EARGF(usage()); break;
case 'f': consflag++; break;
} ARGEND
if(user == nil || host == nil || authserver == nil || port == nil)
usage();
if(pass == nil)
pass = getpass("password:");
gnutls_global_init();
res = gnutls_init(&session, GNUTLS_CLIENT);
if(res != GNUTLS_E_SUCCESS){
sysfatal("could not init session");
}
if(*argv){
pipe(pin);
pipe(pout);
if(consflag){
/*
* Unix has no /dev/cons, so there is no way to read
* and write from the terminal if stdin and stdout
* are dup'd over with the socket. This gives a bit
* of a back door in to the orginal stdin and stdout.
*/
consin = dup(0);
consout = dup(1);
}
switch((execc = fork())){
case -1:
sysfatal("fork");
case 0:
close(pin[1]);
close(pout[0]);
dup2(pin[0], 0);
dup2(pout[1], 1);
execvp(argv[0], argv);
sysfatal("exec");
}
close(pout[1]);
close(pin[0]);
infd = pout[0];
outfd = pin[1];
if(consflag){
/*
* For the sake of portability,
* send the "cons" fds as the first
* to lines to the child process to avoid
* having to assume the next two fds
*/
n = sprint(buf, "%d%d", consin, consout);
write(pin[1], buf, n);
}
}
fd = unix_dial(host, port);
if(fd < 0){
sysfatal("Failed to connect to the client");
}
p9authtls(fd);
switch((xferc = fork())){
case -1:
sysfatal("fork");
case 0:
xfer(infd, -1, s_recv, tls_send);
break;
default:
xfer(-1, outfd, tls_recv, s_send);
break;
}
if(xferc)
kill(xferc, SIGTERM);
if(execc)
kill(execc, SIGTERM);
}
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;
}
/*
* p9any authentication followed by tls-psk encryption
*/
static int
p9authtls(int fd)
{
AuthInfo *ai;
gnutls_psk_client_credentials_t cred;
gnutls_datum_t key;
const char *error = NULL;
int res;
ai = p9any(fd);
if(ai == nil)
sysfatal("can't authenticate: %r");
if(gnutls_psk_allocate_client_credentials(&cred) != 0)
sysfatal("can't allocate client creds");
key.size = ai->nsecret;
key.data = ai->secret;
if(gnutls_psk_set_client_credentials(cred, "p9secret", &key, GNUTLS_PSK_KEY_RAW) != 0)
sysfatal("can't set creds");
if(gnutls_credentials_set(session, GNUTLS_CRD_PSK, cred) != 0)
sysfatal("can't set creds 2");
res = gnutls_priority_set_direct(
session,
"NONE:+VERS-TLS1.2:+SIGN-ALL:+MAC-ALL:+CHACHA20-POLY1305:+PSK:+CTYPE-ALL",
&error
);
if (res != GNUTLS_E_SUCCESS) {
sysfatal("gnutls_priority_set_direct() failed: %s", error);
}
gnutls_transport_set_int(session, fd);
do {
res = gnutls_handshake(session);
} while ( res != 0 && !gnutls_error_is_fatal(res) );
if (gnutls_error_is_fatal(res)) {
sysfatal("Fatal error during handshake");
}
return fd;
}
int
authdial(char *net, char *dom)
{
return unix_dial(authserver, "567");
}
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);
}
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 i, n, m, v2, dp9ik;
Ticketreq tr;
Ticket t;
AuthInfo *ai;
if(readstr(fd, buf, sizeof buf) < 0)
sysfatal("cannot read p9any negotiation: %r");
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)
sysfatal("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)
sysfatal("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)
sysfatal("cannot write user/domain choice in p9any");
if(v2){
if(readstr(fd, buf, sizeof buf) < 0)
sysfatal("cannot read OK in p9any: %r");
if(memcmp(buf, "OK\0", 3) != 0)
sysfatal("did not get OK in p9any: got %s", buf);
}
genrandom(crand, 2*NONCELEN);
genrandom(cchal, CHALLEN);
if(write(fd, cchal, CHALLEN) != CHALLEN)
sysfatal("cannot write p9sk1 challenge: %r");
n = TICKREQLEN;
if(dp9ik)
n += PAKYLEN;
if(readn(fd, trbuf, n) != n || convM2TR(trbuf, TICKREQLEN, &tr) <= 0)
sysfatal("cannot read ticket request in p9sk1: %r");
again:
if(!getkey(&authkey, user, tr.authdom, proto, pass))
sysfatal("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)
sysfatal("cannot get auth tickets in p9sk1: %r");
m = convM2T(tbuf, n, &t, &authkey);
if(m <= 0 || t.num != AuthTc){
print("?password mismatch with auth server\n");
if(pass != nil && *pass)
sysfatal("wrong password");
goto again;
}
n -= m;
memmove(tbuf, tbuf+m, n);
if(dp9ik && write(fd, y, PAKYLEN) != PAKYLEN)
sysfatal("cannot send authpak public key back: %r");
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)
sysfatal("cannot send ticket and authenticator back: %r");
if((n=read(fd, tbuf, m)) != m || memcmp(tbuf, "cpu:", 4) == 0){
if(n <= 4)
sysfatal("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;
sysfatal("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");
sysfatal("server lies");
}
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
getkey(Authkey *key, char *user, char *dom, char *proto, char *pass)
{
if(pass != nil && *pass)
pass = estrdup(pass);
else {
sysfatal("getkey: no password");
}
if(pass != nil){
memset(key, 0, sizeof(*key));
passtokey(key, pass);
if(strcmp(proto, "dp9ik") == 0) {
authpak_hash(key, user);
}
return 1;
}
return 0;
}