From e5888a1ffdae813d7575f5fb02275c6bb07e5199 Mon Sep 17 00:00:00 2001
From: Taru Karttunen <taruti@taruti.net>
Date: Wed, 30 Mar 2011 15:46:40 +0300
Subject: Import sources from 2011-03-30 iso image

---
 sys/src/cmd/vnc/auth.c | 242 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 242 insertions(+)
 create mode 100755 sys/src/cmd/vnc/auth.c

(limited to 'sys/src/cmd/vnc/auth.c')

diff --git a/sys/src/cmd/vnc/auth.c b/sys/src/cmd/vnc/auth.c
new file mode 100755
index 000000000..508c65366
--- /dev/null
+++ b/sys/src/cmd/vnc/auth.c
@@ -0,0 +1,242 @@
+#include "vnc.h"
+#include <libsec.h>
+#include <auth.h>
+
+char *serveraddr;
+
+/*
+ * Encrypt n bytes using the password
+ * as key, padded with zeros to 8 bytes.
+ */
+enum
+{
+	VerLen	= 12
+};
+
+static char version[VerLen+1] = "RFB 003.003\n";
+
+static uchar tab[256];
+
+/* VNC reverses the bits of each byte before using as a des key */
+static void
+mktab(void)
+{
+	int i, j, k;
+	static int once;
+
+	if(once)
+		return;
+	once = 1;
+
+	for(i=0; i<256; i++){
+		j=i;
+		tab[i] = 0;
+		for(k=0; k<8; k++){
+			tab[i] = (tab[i]<<1) | (j&1);
+			j >>= 1;
+		}
+	}
+}
+
+static void
+vncencrypt(uchar *buf, int n, char *pw)
+{
+	uchar *p;
+	uchar key[9];
+	DESstate s;
+
+	mktab();
+	memset(key, 0, sizeof key);
+	strncpy((char*)key, pw, 8);
+	for(p=key; *p; p++)
+		*p = tab[*p];
+
+	setupDESstate(&s, key, nil);
+	desECBencrypt(buf, n, &s);
+}
+
+static int
+readln(char *prompt, char *line, int len)
+{
+	char *p;
+	int fd, ctl, n, nr;
+
+	fd = open("/dev/cons", ORDWR);
+	if(fd < 0)
+		sysfatal("couldn't open cons");
+	ctl = open("/dev/consctl", OWRITE);
+	if(ctl < 0)
+		sysfatal("couldn't open consctl");
+	write(ctl, "rawon", 5);
+	fprint(fd, "%s", prompt);
+	nr = 0;
+	p = line;
+	for(;;){
+		n = read(fd, p, 1);
+		if(n < 0){
+			close(fd);
+			close(ctl);
+			return -1;
+		}
+		if(n == 0 || *p == '\n' || *p == '\r'){
+			*p = '\0';
+			write(fd, "\n", 1);
+			close(fd);
+			close(ctl);
+			return nr;
+		}
+		if(*p == '\b'){
+			if(nr > 0){
+				nr--;
+				p--;
+			}
+		}else if(*p == 21){		/* cntrl-u */
+			fprint(fd, "\n%s", prompt);
+			nr = 0;
+			p = line;
+		}else{
+			nr++;
+			p++;
+		}
+		if(nr == len){
+			fprint(fd, "line too long; try again\n%s", prompt);
+			nr = 0;
+			p = line;
+		}
+	}
+}
+
+int
+vncsrvhandshake(Vnc *v)
+{
+	char msg[VerLen+1];
+
+	strecpy(msg, msg+sizeof msg, version);
+	if(verbose)
+		fprint(2, "server version: %s", msg);
+	vncwrbytes(v, msg, VerLen);
+	vncflush(v);
+
+	vncrdbytes(v, msg, VerLen);
+	if(verbose)
+		fprint(2, "client version: %s", msg);
+	return 0;
+}
+
+int
+vnchandshake(Vnc *v)
+{
+	char msg[VerLen+1];
+
+	msg[VerLen] = 0;
+	vncrdbytes(v, msg, VerLen);
+	if(strncmp(msg, "RFB ", 4) != 0){
+		werrstr("bad rfb version \"%s\"", msg);
+		return -1;
+	}
+	if(verbose)
+		fprint(2, "server version: %s", msg);
+	strcpy(msg, version);
+	vncwrbytes(v, msg, VerLen);
+	vncflush(v);
+	return 0;
+}
+
+int
+vncauth(Vnc *v, char *keypattern)
+{
+	char pw[128], *reason;
+	uchar chal[VncChalLen];
+	ulong auth;
+	char *p, *server;
+
+	if(keypattern == nil)
+		keypattern = "";
+	auth = vncrdlong(v);
+	switch(auth){
+	default:
+		werrstr("unknown auth type 0x%lux", auth);
+		if(verbose)
+			fprint(2, "unknown auth type 0x%lux", auth);
+		return -1;
+
+	case AFailed:
+		reason = vncrdstring(v);
+		werrstr("%s", reason);
+		if(verbose)
+			fprint(2, "auth failed: %s\n", reason);
+		return -1;
+
+	case ANoAuth:
+		if(verbose)
+			fprint(2, "no auth needed");
+		break;
+
+	case AVncAuth:
+		vncrdbytes(v, chal, VncChalLen);
+		server = strdup(serveraddr);
+		p = strrchr(server, ':');
+		if(p)
+			*p = 0;
+		if(auth_respond(chal, VncChalLen, nil, 0, chal, VncChalLen, auth_getkey,
+			"proto=vnc role=client server=%s %s", server, keypattern) != VncChalLen){
+			/* BUG This is for drawterm users who don't start their own factotums */
+			readln("password: ", pw, sizeof(pw));
+			vncencrypt(chal, VncChalLen, pw);
+			memset(pw, 0, sizeof pw);
+		}
+		free(server);
+		vncwrbytes(v, chal, VncChalLen);
+		vncflush(v);
+
+		auth = vncrdlong(v);
+		switch(auth){
+		default:
+			werrstr("unknown server response 0x%lux", auth);
+			return -1;
+		case VncAuthFailed:
+			werrstr("server says authentication failed");
+			return -1;
+		case VncAuthTooMany:
+			werrstr("server says too many tries");
+			return -1;
+		case VncAuthOK:
+			break;
+		}
+		break;
+	}
+	return 0;
+}
+
+int
+vncsrvauth(Vnc *v)
+{
+	Chalstate *c;
+	AuthInfo *ai;
+
+	if((c = auth_challenge("proto=vnc role=server user=%q", getuser()))==nil)
+		sysfatal("vncchal: %r");
+	if(c->nchal != VncChalLen)
+		sysfatal("vncchal got %d bytes wanted %d", c->nchal, VncChalLen);
+	vncwrlong(v, AVncAuth);
+	vncwrbytes(v, c->chal, VncChalLen);
+	vncflush(v);
+
+	vncrdbytes(v, c->chal, VncChalLen);
+	c->resp = c->chal;
+	c->nresp = VncChalLen;
+	ai = auth_response(c);
+	auth_freechal(c);
+	if(ai == nil){
+		fprint(2, "vnc auth failed: server factotum: %r\n");
+		vncwrlong(v, VncAuthFailed);
+		vncflush(v);
+		return -1;
+	}
+	auth_freeAI(ai);
+	vncwrlong(v, VncAuthOK);
+	vncflush(v);
+
+	return 0;
+}
+
-- 
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