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authorTaru Karttunen <taruti@taruti.net>2011-03-30 15:46:40 +0300
committerTaru Karttunen <taruti@taruti.net>2011-03-30 15:46:40 +0300
commite5888a1ffdae813d7575f5fb02275c6bb07e5199 (patch)
treed8d51eac403f07814b9e936eed0c9a79195e2450 /sys/src/cmd/vnc/auth.c
Import sources from 2011-03-30 iso image
Diffstat (limited to 'sys/src/cmd/vnc/auth.c')
-rwxr-xr-xsys/src/cmd/vnc/auth.c242
1 files changed, 242 insertions, 0 deletions
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;
+}
+