22 MSG_USERAUTH_REQUEST = 50,
27 MSG_USERAUTH_PK_OK = 60,
28 MSG_USERAUTH_INFO_REQUEST = 60,
29 MSG_USERAUTH_INFO_RESPONSE = 61,
31 MSG_GLOBAL_REQUEST = 80,
35 MSG_CHANNEL_OPEN = 90,
36 MSG_CHANNEL_OPEN_CONFIRMATION,
37 MSG_CHANNEL_OPEN_FAILURE,
38 MSG_CHANNEL_WINDOW_ADJUST,
40 MSG_CHANNEL_EXTENDED_DATA,
50 Overhead = 256, // enougth for MSG_CHANNEL_DATA header
52 WinPackets = 8, // (1<<15) * 8 = 256K
55 int MaxPwTries = 3; // retry this often for keyboard-interactive
72 uchar b[Overhead + MaxPacket];
81 char thumb[2*SHA2_256dlen+1], *thumbfile;
83 int fd, intr, raw, debug;
84 char *user, *service, *status, *host, *cmd;
92 recv.eof = send.eof = 1;
94 postnote(PNPROC, send.pid, "shutdown");
98 catch(void*, char *msg)
100 if(strcmp(msg, "interrupt") == 0){
115 memset(err, 0, sizeof(err));
116 errstr(err, sizeof(err));
117 r = strcmp(err, "interrupted") == 0;
118 errstr(err, sizeof(err));
122 #define PUT4(p, u) (p)[0] = (u)>>24, (p)[1] = (u)>>16, (p)[2] = (u)>>8, (p)[3] = (u)
123 #define GET4(p) (u32int)(p)[3] | (u32int)(p)[2]<<8 | (u32int)(p)[1]<<16 | (u32int)(p)[0]<<24
126 vpack(uchar *p, int n, char *fmt, va_list a)
128 uchar *p0 = p, *e = p+n;
139 if(++p > e) goto err;
142 *va_arg(a, void**) = p;
146 *p++ = va_arg(a, int);
149 m = va_arg(a, mpint*);
150 u = (mpsignif(m)+8)/8;
151 if(p+4 > e) goto err;
153 if(u > e-p) goto err;
154 mptober(m, p, u), p += u;
158 s = va_arg(a, void*);
161 if(p+4 > e) goto err;
164 if(u > e-p) goto err;
170 if(p+4 > e) goto err;
180 vunpack(uchar *p, int n, char *fmt, va_list a)
182 uchar *p0 = p, *e = p+n;
192 if(++p > e) goto err;
195 *va_arg(a, void**) = p;
199 *va_arg(a, int*) = *p++;
202 if(p+4 > e) goto err;
204 if(u > e-p) goto err;
205 m = va_arg(a, mpint*);
206 betomp(p, u, m), p += u;
209 if(p+4 > e) goto err;
211 if(u > e-p) goto err;
212 *va_arg(a, void**) = p;
213 *va_arg(a, int*) = u;
217 s = va_arg(a, void*);
219 if(u > e-p) goto err;
224 if(p+4 > e) goto err;
226 *va_arg(a, int*) = u;
236 pack(uchar *p, int n, char *fmt, ...)
240 n = vpack(p, n, fmt, a);
245 unpack(uchar *p, int n, char *fmt, ...)
249 n = vunpack(p, n, fmt, a);
255 setupcs(Oneway *c, uchar otk[32])
260 pack(iv, sizeof(iv), "uu", 0, c->seq);
261 chacha_setiv(&c->cs1, iv);
262 chacha_setiv(&c->cs2, iv);
263 chacha_setblock(&c->cs1, 0);
264 chacha_setblock(&c->cs2, 0);
265 chacha_encrypt(otk, 32, &c->cs2);
269 sendpkt(char *fmt, ...)
271 static uchar buf[sizeof(send.b)];
276 n = vpack(send.b, sizeof(send.b), fmt, a);
279 toobig: sysfatal("sendpkt: message too big");
286 fprint(2, "sendpkt: (%d) %.*H\n", send.r[0], (int)(send.w-send.r), send.r);
290 pad = ChachaBsize - ((5+n) % ChachaBsize) + 4;
292 for(pad=4; (5+n+pad) % 8; pad++)
296 n = pack(buf, sizeof(buf)-16, "ub[[", 1+n+pad, pad, send.b, n, send.w, pad);
297 if(n < 0) goto toobig;
302 chacha_encrypt(buf, 4, &send.cs1);
303 chacha_encrypt(buf+4, n-4, &send.cs2);
304 poly1305(buf, n, otk, sizeof(otk), buf+n, nil);
308 if(write(fd, buf, n) != n)
309 sysfatal("write: %r");
315 readall(int fd, uchar *data, int len)
319 for(tot = 0; tot < len; tot += n){
320 n = read(fd, data+tot, len-tot);
322 if(n < 0 && wasintr()){
336 uchar otk[32], tag[16];
337 DigestState *ds = nil;
340 if(readall(fd, recv.b, 4) != 4)
341 sysfatal("read1: %r");
344 ds = poly1305(recv.b, 4, otk, sizeof(otk), nil, nil);
345 chacha_encrypt(recv.b, 4, &recv.cs1);
346 unpack(recv.b, 4, "u", &n);
349 unpack(recv.b, 4, "u", &n);
351 if(n < 8 || n > sizeof(recv.b)){
352 badlen: sysfatal("bad length %d", n);
354 if(readall(fd, recv.b, n) != n)
355 sysfatal("read2: %r");
358 if(n < 0) goto badlen;
359 poly1305(recv.b, n, otk, sizeof(otk), tag, ds);
360 if(tsmemcmp(tag, recv.b+n, 16) != 0)
362 chacha_encrypt(recv.b, n, &recv.cs2);
365 if(n < 1) goto badlen;
372 fprint(2, "recvpkt: (%d) %.*H\n", recv.r[0], (int)(recv.w-recv.r), recv.r);
377 static char sshrsa[] = "ssh-rsa";
380 rsapub2ssh(RSApub *rsa, uchar *data, int len)
382 return pack(data, len, "smm", sshrsa, sizeof(sshrsa)-1, rsa->ek, rsa->n);
386 ssh2rsapub(uchar *data, int len)
395 if(unpack(data, len, "smm", &s, &n, pub->ek, pub->n) < 0
396 || n != sizeof(sshrsa)-1 || memcmp(s, sshrsa, n) != 0){
404 rsasig2ssh(RSApub *pub, mpint *S, uchar *data, int len)
406 int l = (mpsignif(pub->n)+7)/8;
409 mptober(S, data+4+7+4, l);
410 return pack(data, len, "ss", sshrsa, sizeof(sshrsa)-1, data+4+7+4, l);
414 ssh2rsasig(uchar *data, int len)
421 if(unpack(data, len, "sm", &s, &n, m) < 0
422 || n != sizeof(sshrsa)-1 || memcmp(s, sshrsa, n) != 0){
430 pkcs1digest(uchar *data, int len, RSApub *pub)
432 uchar digest[SHA1dlen], buf[256];
434 sha1(data, len, digest, nil);
435 return pkcs1padbuf(buf, asn1encodedigest(sha1, digest, buf, sizeof(buf)), pub->n, 1);
439 pkcs1verify(uchar *data, int len, RSApub *pub, mpint *S)
444 V = pkcs1digest(data, len, pub);
447 rsaencrypt(pub, S, S);
448 ret = mpcmp(V, S) == 0;
455 hashstr(void *data, ulong len, DigestState *ds)
458 pack(l, 4, "u", len);
459 return sha2_256((uchar*)data, len, nil, sha2_256(l, 4, nil, ds));
463 kdf(uchar *k, int nk, uchar *h, char x, uchar *out, int len)
465 uchar digest[SHA2_256dlen], *out0;
469 ds = hashstr(k, nk, nil);
470 ds = sha2_256(h, sizeof(digest), nil, ds);
471 ds = sha2_256((uchar*)&x, 1, nil, ds);
472 sha2_256(sid, nsid, digest, ds);
475 if(n > sizeof(digest))
477 memmove(out, digest, n);
482 ds = hashstr(k, nk, nil);
483 ds = sha2_256(h, sizeof(digest), nil, ds);
484 sha2_256(out0, out-out0, digest, ds);
491 static char kexalgs[] = "curve25519-sha256,curve25519-sha256@libssh.org";
492 static char cipheralgs[] = "chacha20-poly1305@openssh.com";
493 static char zipalgs[] = "none";
494 static char macalgs[] = "";
495 static char langs[] = "";
497 uchar cookie[16], x[32], yc[32], z[32], k[32+1], h[SHA2_256dlen], *ys, *ks, *sig;
498 uchar k12[2*ChachaKeylen];
499 int i, nk, nys, nks, nsig;
504 ds = hashstr(send.v, strlen(send.v), nil);
505 ds = hashstr(recv.v, strlen(recv.v), ds);
507 genrandom(cookie, sizeof(cookie));
508 sendpkt("b[ssssssssssbu", MSG_KEXINIT,
509 cookie, sizeof(cookie),
510 kexalgs, sizeof(kexalgs)-1,
511 sshrsa, sizeof(sshrsa)-1,
512 cipheralgs, sizeof(cipheralgs)-1,
513 cipheralgs, sizeof(cipheralgs)-1,
514 macalgs, sizeof(macalgs)-1,
515 macalgs, sizeof(macalgs)-1,
516 zipalgs, sizeof(zipalgs)-1,
517 zipalgs, sizeof(zipalgs)-1,
518 langs, sizeof(langs)-1,
519 langs, sizeof(langs)-1,
522 ds = hashstr(send.r, send.w-send.r, ds);
525 Next0: switch(recvpkt()){
533 ds = hashstr(recv.r, recv.w-recv.r, ds);
537 "kexalgs", "hostalgs",
538 "cipher1", "cipher2",
544 uchar *p = recv.r+17;
546 for(t=tab; *t != nil; t++){
547 if(unpack(p, recv.w-p, "s.", &s, &n, &p) < 0)
549 fprint(2, "%s: %.*s\n", *t, n, s);
553 curve25519_dh_new(x, yc);
556 sendpkt("bs", MSG_ECDH_INIT, yc, sizeof(yc));
557 Next1: switch(recvpkt()){
562 sysfatal("inception");
564 if(unpack(recv.r, recv.w-recv.r, "_sss", &ks, &nks, &ys, &nys, &sig, &nsig) < 0)
565 sysfatal("bad ECDH_REPLY");
570 sysfatal("bad server ECDH ephermal public key length");
572 ds = hashstr(ks, nks, ds);
573 ds = hashstr(yc, 32, ds);
574 ds = hashstr(ys, 32, ds);
579 sha2_256(ks, nks, h, nil);
580 i = enc64(thumb, sizeof(thumb), h, sizeof(h));
581 while(i > 0 && thumb[i-1] == '=')
586 fprint(2, "host fingerprint: %s\n", thumb);
588 ok = initThumbprints(thumbfile, nil, "ssh");
589 if(ok == nil || !okThumbprint(h, sizeof(h), ok)){
590 if(ok != nil) werrstr("unknown host");
591 fprint(2, "%s: %r\n", argv0);
592 fprint(2, "verify hostkey: %s %.*[\n", sshrsa, nks, ks);
593 fprint(2, "add thumbprint after verification:\n");
594 fprint(2, "\techo 'ssh sha256=%s server=%s' >> %q\n", thumb, host, thumbfile);
595 sysfatal("checking hostkey failed: %r");
600 if((pub = ssh2rsapub(ks, nks)) == nil)
601 sysfatal("bad server public key");
602 if((S = ssh2rsasig(sig, nsig)) == nil)
603 sysfatal("bad server signature");
605 curve25519_dh_finish(x, ys, z);
607 K = betomp(z, 32, nil);
608 nk = (mpsignif(K)+8)/8;
612 ds = hashstr(k, nk, ds);
613 sha2_256(nil, 0, h, ds);
614 if(!pkcs1verify(h, sizeof(h), pub, S))
615 sysfatal("server verification failed");
619 sendpkt("b", MSG_NEWKEYS);
620 Next2: switch(recvpkt()){
625 sysfatal("inception");
630 /* next key exchange */
631 recv.kex = recv.seq + 100000;
632 send.kex = send.seq + 100000;
635 memmove(sid, h, nsid = sizeof(h));
637 kdf(k, nk, h, 'C', k12, sizeof(k12));
638 setupChachastate(&send.cs1, k12+1*ChachaKeylen, ChachaKeylen, nil, 64/8, 20);
639 setupChachastate(&send.cs2, k12+0*ChachaKeylen, ChachaKeylen, nil, 64/8, 20);
641 kdf(k, nk, h, 'D', k12, sizeof(k12));
642 setupChachastate(&recv.cs1, k12+1*ChachaKeylen, ChachaKeylen, nil, 64/8, 20);
643 setupChachastate(&recv.cs2, k12+0*ChachaKeylen, ChachaKeylen, nil, 64/8, 20);
646 static char *authnext;
651 int ok = authnext == nil || strstr(authnext, meth) != nil;
653 fprint(2, "userauth %s %s\n", meth, ok ? "ok" : "skipped");
658 authfailure(char *meth)
663 if(unpack(recv.r, recv.w-recv.r, "_sb", &s, &n, &partial) < 0)
664 sysfatal("bad auth failure response");
666 authnext = smprint("%.*s", n, s);
668 fprint(2, "userauth %s failed: partial=%d, next=%s\n", meth, partial, authnext);
669 return partial != 0 || !authok(meth);
675 static char authmeth[] = "none";
677 if(!authok(authmeth))
680 sendpkt("bsss", MSG_USERAUTH_REQUEST,
682 service, strlen(service),
683 authmeth, sizeof(authmeth)-1);
685 Next0: switch(recvpkt()){
689 case MSG_USERAUTH_FAILURE:
690 werrstr("authentication needed");
691 authfailure(authmeth);
693 case MSG_USERAUTH_SUCCESS:
701 static char authmeth[] = "publickey";
703 uchar pk[4096], sig[4096];
712 if(!authok(authmeth))
715 if((afd = open("/mnt/factotum/rpc", ORDWR)) < 0)
717 if((rpc = auth_allocrpc(afd)) == nil){
722 s = "proto=rsa service=ssh role=client";
723 if(auth_rpc(rpc, "start", s, strlen(s)) != ARok){
733 while(auth_rpc(rpc, "read", nil, 0) == ARok){
735 if(strtomp(s, &s, 16, pub->n) == nil)
739 if(strtomp(s, nil, 16, pub->ek) == nil)
741 npk = rsapub2ssh(pub, pk, sizeof(pk));
743 sendpkt("bsssbss", MSG_USERAUTH_REQUEST,
745 service, strlen(service),
746 authmeth, sizeof(authmeth)-1,
748 sshrsa, sizeof(sshrsa)-1,
750 Next1: switch(recvpkt()){
754 case MSG_USERAUTH_FAILURE:
755 if(authfailure(authmeth))
758 case MSG_USERAUTH_SUCCESS:
759 case MSG_USERAUTH_PK_OK:
763 /* sign sid and the userauth request */
764 n = pack(send.b, sizeof(send.b), "sbsssbss",
766 MSG_USERAUTH_REQUEST,
768 service, strlen(service),
769 authmeth, sizeof(authmeth)-1,
771 sshrsa, sizeof(sshrsa)-1,
773 S = pkcs1digest(send.b, n, pub);
774 n = snprint((char*)send.b, sizeof(send.b), "%B", S);
777 if(auth_rpc(rpc, "write", (char*)send.b, n) != ARok)
779 if(auth_rpc(rpc, "read", nil, 0) != ARok)
782 S = strtomp(rpc->arg, nil, 16, nil);
783 nsig = rsasig2ssh(pub, S, sig, sizeof(sig));
786 /* send final userauth request with the signature */
787 sendpkt("bsssbsss", MSG_USERAUTH_REQUEST,
789 service, strlen(service),
790 authmeth, sizeof(authmeth)-1,
792 sshrsa, sizeof(sshrsa)-1,
795 Next2: switch(recvpkt()){
799 case MSG_USERAUTH_FAILURE:
800 if(authfailure(authmeth))
803 case MSG_USERAUTH_SUCCESS:
821 static char authmeth[] = "password";
824 if(!authok(authmeth))
827 up = auth_getuserpasswd(auth_getkey, "proto=pass service=ssh user=%q server=%q thumb=%q",
832 sendpkt("bsssbs", MSG_USERAUTH_REQUEST,
834 service, strlen(service),
835 authmeth, sizeof(authmeth)-1,
837 up->passwd, strlen(up->passwd));
839 memset(up->passwd, 0, strlen(up->passwd));
842 Next0: switch(recvpkt()){
846 case MSG_USERAUTH_FAILURE:
847 werrstr("wrong password");
848 authfailure(authmeth);
850 case MSG_USERAUTH_SUCCESS:
858 static char authmeth[] = "keyboard-interactive";
861 char *name, *inst, *s, *a;
867 if(!authok(authmeth))
871 if(++tries > MaxPwTries)
874 sendpkt("bsssss", MSG_USERAUTH_REQUEST,
876 service, strlen(service),
877 authmeth, sizeof(authmeth)-1,
881 Next0: switch(recvpkt()){
885 case MSG_USERAUTH_FAILURE:
886 werrstr("keyboard-interactive failed");
887 if(authfailure(authmeth))
890 case MSG_USERAUTH_SUCCESS:
892 case MSG_USERAUTH_INFO_REQUEST:
896 if((fd = open("/dev/cons", OWRITE)) < 0)
899 if(unpack(recv.r, recv.w-recv.r, "_ss.", &name, &n, &inst, &m, &recv.r) < 0)
900 sysfatal("bad info request: name, inst");
902 while(n > 0 && strchr("\r\n\t ", name[n-1]) != nil)
904 while(m > 0 && strchr("\r\n\t ", inst[m-1]) != nil)
908 fprint(fd, "%.*s\n", n, name);
910 fprint(fd, "%.*s\n", m, inst);
913 if(unpack(recv.r, recv.w-recv.r, "su.", &s, &n, &nquest, &recv.r) < 0)
914 sysfatal("bad info request: lang, #quest");
917 for(i = 0; i < nquest; i++){
918 if(unpack(recv.r, recv.w-recv.r, "sb.", &s, &n, &echo, &recv.r) < 0)
919 sysfatal("bad info request: question [%d]", i);
921 while(n > 0 && strchr("\r\n\t :", s[n-1]) != nil)
925 if((a = readcons(s, nil, !echo)) == nil)
926 sysfatal("readcons: %r");
930 if((s = realloc(ans, n + m)) == nil)
931 sysfatal("realloc: %r");
934 answ += pack(answ, m, "s", a, m-4);
937 sendpkt("bu[", MSG_USERAUTH_INFO_RESPONSE, i, ans, answ - ans);
941 Next1: switch(recvpkt()){
945 case MSG_USERAUTH_INFO_REQUEST:
947 case MSG_USERAUTH_FAILURE:
948 werrstr("keyboard-interactive failed");
949 if(authfailure(authmeth))
952 case MSG_USERAUTH_SUCCESS:
966 case MSG_GLOBAL_REQUEST:
969 if(unpack(recv.r, recv.w-recv.r, "_us", &c, &s, &n) < 0)
971 sysfatal("disconnect: (%d) %.*s", c, n, s);
974 if(unpack(recv.r, recv.w-recv.r, "__sb", &s, &n, &c) < 0)
976 if(c != 0 || debug) fprint(2, "%s: %.*s\n", argv0, n, s);
978 case MSG_USERAUTH_BANNER:
979 if(unpack(recv.r, recv.w-recv.r, "_s", &s, &n) < 0)
981 if(raw) write(2, s, n);
983 case MSG_CHANNEL_DATA:
984 if(unpack(recv.r, recv.w-recv.r, "_us", &c, &s, &n) < 0)
988 if(write(1, s, n) != n)
989 sysfatal("write out: %r");
992 if(recv.win < recv.pkt){
993 n = WinPackets*recv.pkt;
995 sendpkt("buu", MSG_CHANNEL_WINDOW_ADJUST, send.chan, n);
998 case MSG_CHANNEL_EXTENDED_DATA:
999 if(unpack(recv.r, recv.w-recv.r, "_uus", &c, &b, &s, &n) < 0)
1003 if(b == 1) write(2, s, n);
1005 case MSG_CHANNEL_WINDOW_ADJUST:
1006 if(unpack(recv.r, recv.w-recv.r, "_uu", &c, &n) < 0)
1011 if(send.win >= send.pkt)
1014 case MSG_CHANNEL_REQUEST:
1015 if(unpack(recv.r, recv.w-recv.r, "_usb.", &c, &s, &n, &b, &p) < 0)
1019 if(n == 11 && memcmp(s, "exit-signal", n) == 0){
1020 if(unpack(p, recv.w-p, "s", &s, &n) < 0)
1022 if(n != 0 && status == nil)
1023 status = smprint("%.*s", n, s);
1024 } else if(n == 11 && memcmp(s, "exit-status", n) == 0){
1025 if(unpack(p, recv.w-p, "u", &n) < 0)
1027 if(n != 0 && status == nil)
1028 status = smprint("%d", n);
1030 fprint(2, "%s: channel request: %.*s\n", argv0, n, s);
1033 case MSG_CHANNEL_EOF:
1035 if(!raw) write(1, "", 0);
1037 case MSG_CHANNEL_CLOSE:
1044 sysfatal("got: %.*H", (int)(recv.w - recv.r), recv.r);
1052 for(p = send.b; p < &send.b[sizeof(send.b)-1]; p++){
1054 if(read(fd, p, 1) != 1 || *p == '\n')
1057 while(p >= send.b && (*p == '\n' || *p == '\r'))
1059 return (char*)send.b;
1075 if(s = getenv("XPIXELS")){
1076 tty.xpixels = atoi(s);
1079 if(s = getenv("YPIXELS")){
1080 tty.ypixels = atoi(s);
1083 if(s = getenv("LINES")){
1084 tty.lines = atoi(s);
1087 if(s = getenv("COLS")){
1099 if(open("/dev/cons", OREAD) != 0)
1100 sysfatal("open: %r");
1102 if(open("/dev/cons", OWRITE) != 1)
1103 sysfatal("open: %r");
1105 if((ctl = open("/dev/consctl", OWRITE)) >= 0){
1106 write(ctl, "rawon", 5);
1107 write(ctl, "winchon", 7); /* vt(1): interrupt note on window change */
1112 #pragma varargck type "k" char*
1119 s = va_arg(f->args, char*);
1120 n = fmtstrcpy(f, "'");
1121 while((p = strchr(s, '\'')) != nil){
1123 n += fmtstrcpy(f, s);
1125 n += fmtstrcpy(f, "'\\''");
1128 n += fmtstrcpy(f, s);
1129 n += fmtstrcpy(f, "'");
1136 fprint(2, "usage: %s [-dR] [-t thumbfile] [-T tries] [-u user] [-h] [user@]host [cmd args...]\n", argv0);
1141 main(int argc, char *argv[])
1148 fmtinstall('B', mpfmt);
1149 fmtinstall('H', encodefmt);
1150 fmtinstall('[', encodefmt);
1151 fmtinstall('k', kfmt);
1153 tty.term = getenv("TERM");
1154 raw = tty.term != nil && *tty.term != 0;
1164 raw = 2; /* bloody */
1167 user = EARGF(usage());
1170 host = EARGF(usage());
1173 thumbfile = EARGF(usage());
1176 MaxPwTries = strtol(EARGF(usage()), &s, 0);
1177 if(*s != 0) usage();
1188 s = strchr(host, '@');
1196 for(cmd = nil; *argv != nil; argv++){
1198 cmd = strdup(*argv);
1202 s = smprint("%s %k", cmd, *argv);
1208 if((fd = dial(netmkaddr(host, nil, "ssh"), nil, nil, nil)) < 0)
1209 sysfatal("dial: %r");
1211 send.v = "SSH-2.0-(9)";
1212 fprint(fd, "%s\r\n", send.v);
1213 recv.v = readline();
1215 fprint(2, "server verison: %s\n", recv.v);
1216 if(strncmp("SSH-2.0-", recv.v, 8) != 0)
1217 sysfatal("bad server version: %s", recv.v);
1218 recv.v = strdup(recv.v);
1220 send.l = recv.l = &sl;
1224 if(thumbfile == nil)
1225 thumbfile = smprint("%s/lib/sshthumbs", getenv("home"));
1229 sendpkt("bs", MSG_SERVICE_REQUEST, "ssh-userauth", 12);
1230 Next0: switch(recvpkt()){
1234 case MSG_SERVICE_ACCEPT:
1238 service = "ssh-connection";
1239 if(noneauth() < 0 && pubkeyauth() < 0 && passauth() < 0 && kbintauth() < 0)
1240 sysfatal("auth: %r");
1242 recv.pkt = MaxPacket;
1243 recv.win = WinPackets*recv.pkt;
1246 /* open hailing frequencies */
1247 sendpkt("bsuuu", MSG_CHANNEL_OPEN,
1253 Next1: switch(recvpkt()){
1257 case MSG_CHANNEL_OPEN_FAILURE:
1258 if(unpack(recv.r, recv.w-recv.r, "_uus", &c, &b, &s, &n) < 0)
1259 n = strlen(s = "???");
1260 sysfatal("channel open failure: (%d) %.*s", b, n, s);
1261 case MSG_CHANNEL_OPEN_CONFIRMATION:
1265 if(unpack(recv.r, recv.w-recv.r, "_uuuu", &recv.chan, &send.chan, &send.win, &send.pkt) < 0)
1266 sysfatal("bad channel open confirmation");
1267 if(send.pkt <= 0 || send.pkt > MaxPacket)
1268 send.pkt = MaxPacket;
1273 recv.pid = getpid();
1274 n = rfork(RFPROC|RFMEM);
1276 sysfatal("fork: %r");
1278 /* parent reads and dispatches packets */
1281 while(recv.eof == 0){
1285 if((int)(send.kex - send.seq) <= 0 || (int)(recv.kex - recv.seq) <= 0)
1292 /* child reads input and sends packets */
1296 sendpkt("busbsuuuus", MSG_CHANNEL_REQUEST,
1300 tty.term, strlen(tty.term),
1308 sendpkt("busb", MSG_CHANNEL_REQUEST,
1312 } else if(*cmd == '#') {
1313 sendpkt("busbs", MSG_CHANNEL_REQUEST,
1317 cmd+1, strlen(cmd)-1);
1319 sendpkt("busbs", MSG_CHANNEL_REQUEST,
1326 static uchar buf[MaxPacket];
1328 n = read(0, buf, send.pkt);
1332 if(n < 0 && wasintr()){
1336 sendpkt("busbuuuu", MSG_CHANNEL_REQUEST,
1338 "window-change", 13,
1344 sendpkt("busbs", MSG_CHANNEL_REQUEST,
1358 sendpkt("bus", MSG_CHANNEL_DATA,
1363 sendpkt("bu", raw ? MSG_CHANNEL_CLOSE : MSG_CHANNEL_EOF, send.chan);