* Encrypting tunnel for userv-ipif tunnels, actual implementation
*
* usage:
- * udptunnel-forwarder <public-local-fd> <private-in-fd> <private-out-fd>
+ * udptunnel-forwarder <optchars>
+ * <public-local-fd> <private-in-fd> <private-out-fd>
+ * <encdec-keys-fd>
* <mtu> <keepalive> <timeout>
* <public-remote-addr> [<public-remote-port>]
- * <encdec-keys-fd> <encdec-keys-write>
* <mech1> [<mech1-params> ...]
* <mech2> [<mech2-params> ...]
* ''
* whereever we get a good packet from first, in which case port
* should not be specified.
*
- * <enc-keys-write> is '' to mean read, anything else to mean write.
+ * <optchars> is zero or more of
+ * w means generate and write encdec keys, rather than reading them
+ * D means do crypto debug (use with care!)
*
* Every must be numeric. There is very little argument checking.
*
static size_t buffer_size;
+static const char *opt_chars;
static int public_local_fd, private_in_fd, private_out_fd;
static int mtu2, keepalive, timeout;
static int public_remote_specd;
static struct sockaddr_in public_remote;
-static int encdec_keys_fd, encdec_keys_write;
+static int encdec_keys_fd, encdec_keys_write, crypto_debug;
static int n_mechs;
static const struct mechanism *mechs[MAXMECHS];
static time_t nextsendka;
+static void cdebug(int mechno /*or -1*/, const char *msg) {
+ if (!crypto_debug) return;
+ printf("%s: CRYPTO: %-20s encrypt setup\n",
+ programid,
+ mechno >= 0 ? mechs[i]->name : "",
+ msg);
+}
+
+static void cdebughex(int mechno /*or -1*/, const char *msg,
+ size_t skipbefore, const void *ptr, size_t sz, size_t skipafter) {
+ const unsigned char *p;
+
+ if (!crypto_debug) return;
+ printf("%s: CRYPTO: %-20s %s",
+ programid,
+ mechno >= 0 ? mechs[i]->name : "",
+ msg);
+ for (i=0; i<skipbefore) fputs(" ..",stdout);
+ for (i=0, p=ptr; i<sz; i++, p++) fprintf(" %02x",*p);
+ for (i=0; i<skipafter) fputs(" ..",stdout);
+ fputc('\n',stdout);
+}
+
+void get_random(void *ptr, size_t sz) {
+ static FILE *randfile;
+
+ size_t r;
+
+ if (!randfile) {
+ randfile= fopen("/dev/urandom","rb");
+ if (!randfile && errno==ENOENT) randfile= fopen("/dev/random","rb");
+ if (!randfile) sysfail("open random number generator");
+ }
+
+ r= fread(ptr,1,sz,randfile);
+ if (r == sz) return;
+ (ferror(randfile) ? sysfail : fail)("cannot read random number generator");
+
+ cdebughex(-1, "get_random", ptr, sz, 0,0);
+}
void random_key(void *ptr, size_t sz) {
if (encdec_keys_write) {
int r, i, different, this_saddrlen;
const char *emsg;
+ buf_in.start= buf_in.base+1;
+ buf_in.size= buffer_size-2;
+
setnonblock(public_local_fd,1);
this_saddrlen= sizeof(this_saddr);
- r= recvfrom(public_local_fd, buf_in.base, buffer_size-1, 0,
+ r= recvfrom(public_local_fd, buf_in.start, buf_in.size, 0,
&this_saddr, &this_saddrlen);
if (!r) { diag("empty ciphertext"); return; }
return;
}
if (this_saddr.sin_family != AF_INET) {
- fprintf(stderr,"%s: received unknown AF %lu",
+ fprintf(stderr,"%s: received unknown AF %lu\n",
programid, (unsigned long)this_saddr.sin_family);
return;
}
assert(this_saddrlen == sizeof(this_saddr));
- buf_in.size= buffer_size;
- buf_in.start= buf_in.base;
+ assert(r <= buf_in.size);
+ buf_in.size= r;
for (i=n_mechs-1; i>=0; i--) {
emsg= mechs[i]->decode(md_in[i],&buf_in);
if (emsg) {
alarm(timeout);
- different= !public_remote_specd ||
- memcmp(&this_saddr,&public_remote,sizeof(this_saddr));
+ different= (!public_remote_specd ||
+ public_remote.sin_addr.s_addr != this_saddr.sin_addr.s_addr ||
+ public_remote.sin_port != this_saddr.sin_port);
if (different) {
if (public_remote_specd==2) {
- fprintf(stderr, "%s: packet from unexpected sender %s:%lu",
+ fprintf(stderr, "%s: packet from unexpected sender %s:%lu\n",
programid, inet_ntoa(this_saddr.sin_addr),
- (unsigned long)this_saddr.sin_port);
+ (unsigned long)ntohs(this_saddr.sin_port));
return;
}
- fprintf(stderr, "%s: tunnel open with peer %s:%lu",
+ fprintf(stderr, "%s: tunnel open with peer %s:%lu\n",
programid, inet_ntoa(this_saddr.sin_addr),
- (unsigned long)this_saddr.sin_port);
+ (unsigned long)ntohs(this_saddr.sin_port));
nextsendka= now();
public_remote_specd= 1;
memcpy(&public_remote,&this_saddr,sizeof(public_remote));
}
any_recvd= 1;
-
- buf_in.start[buf_in.size]= 0300;
- *--buf_in.start= 0300;
- buf_in.size+= 2;
+
+ if (!buf_in.size || *buf_in.start != 0300) {
+ *--buf_in.start= 0300;
+ buf_in.size++;
+ }
+ if (buf_in.start[buf_in.size-1] != 0300) {
+ buf_in.start[buf_in.size++]= 0300;
+ }
setnonblock(private_in_fd,0);
write_must(private_in_fd, buf_in.start, buf_in.size, "write down");
after_eaten= accum_buf;
while ((delim= memchr(after_eaten, 0300, accum_used))) {
this_packet= delim - after_eaten;
- sendpacket(after_eaten, this_packet);
+ if (this_packet) sendpacket(after_eaten, this_packet);
accum_used -= this_packet+1;
after_eaten = delim+1;
}
if (uname(&uname_result)) { perror(PROGRAM ": uname failed"); exit(16); }
sprintf(programid, PROGRAM ": %.*s", SYS_NMLN, uname_result.nodename);
-
+
+ opt_chars= getarg_string();
+ encdec_keys_write= !!strchr(opt_chars,"w");
+ crypto_debug= !!strchr(opt_chars,"D");
+
public_local_fd= getarg_ulong();
private_in_fd= getarg_ulong();
private_out_fd= getarg_ulong();
+ encdec_keys_fd= getarg_ulong();
+
mtu2= getarg_ulong() * 2;
keepalive= getarg_ulong();
timeout= getarg_ulong();
arg= getarg_string();
if (*arg) {
public_remote_specd= 1;
+ public_remote.sin_family= AF_INET;
arg_assert(inet_aton(arg,&public_remote.sin_addr));
- public_remote.sin_port= getarg_ulong();
+ public_remote.sin_port= htons(getarg_ulong());
}
- encdec_keys_fd= getarg_ulong();
- encdec_keys_write= !!*getarg_string();
+ if (crypto_debug) {
+ diag("crypto debugging enabled!");
+ setvbuf(stdout,0,_IOLBF,0);
+ }
maxprefix= 0;
- for (i=0; i<n_mechs; i++) mechs[i]= getarg_mech();
- for (i=0; i<n_mechs; i++) mechs[i]->encsetup(&md_in[i], &maxprefix, &maxsuffix);
- for (i=0; i<n_mechs; i++) mechs[i]->decsetup(&md_out[i]);
+ for (i=0; i<n_mechs; i++) {
+ mechs[i]= getarg_mech();
+ }
+ for (i=0; i<n_mechs; i++) {
+ cdebug(i,"encrypt setup");
+ mechs[i]->encsetup(&md_in[i], &maxprefix, &maxsuffix);
+ }
+ for (i=0; i<n_mechs; i++) {
+ cdebug(i,"decrypt setup");
+ mechs[i]->decsetup(&md_out[i]);
+ }
if (maxprefix<1) maxprefix= 1;
if (maxsuffix<1) maxsuffix= 1;
if (keepalive) {
tnow= now();
- if (tnow >= nextsendka) sendpacket("\300",1);
+ if (tnow >= nextsendka && public_remote_specd) sendpacket("\300",1);
polltimeout= (nextsendka - tnow)*1000;
} else {
polltimeout= -1;
if (r==-1 && errno==EINTR) continue;
if (r==-1) sysfail("poll");
- if (pollfds[0].revents & POLLIN) inbound();
- if (pollfds[1].revents & POLLOUT) outbound();
+ if (pollfds[0].revents & (POLLIN|POLLERR)) inbound();
+ if (pollfds[1].revents & (POLLIN|POLLERR)) outbound();
}
}
~ian / userv-utils.git / blobdiff