implement HTTP proxy authentication support, very useful in a ssh_config

ProxyCommand; ok beck@

3 files changed, 95 insertions, 23 deletions

diff --git a/usr.bin/nc/nc.1 b/usr.bin/nc/nc.1
index 85e18a53f71..2b87caa9158 100644
--- a/usr.bin/nc/nc.1
+++ b/usr.bin/nc/nc.1
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: nc.1,v 1.41 2005/10/25 03:51:06 dtucker Exp $
+.\"     $OpenBSD: nc.1,v 1.42 2006/01/25 23:21:37 djm Exp $
 .\"
 .\" Copyright (c) 1996 David Sacerdote
 .\" All rights reserved.
@@ -36,6 +36,7 @@
 .Bk -words
 .Op Fl 46DdhklnrStUuvz
 .Op Fl i Ar interval
+.Op Fl P Ar proxy_username
 .Op Fl p Ar source_port
 .Op Fl s Ar source_ip_address
 .Op Fl T Ar ToS
@@ -128,6 +129,10 @@ option are ignored.
 .It Fl n
 Do not do any DNS or service lookups on any specified addresses,
 hostnames or ports.
+.It Fl P Ar proxy_username
+Specifies a username to present to a proxy server that requires authentication.
+If no username is specified then authentication will not be attempted.
+Proxy authentication is only supported for HTTP CONNECT proxies at present.
 .It Fl p Ar source_port
 Specifies the source port
 .Nm
@@ -386,6 +391,12 @@ directive in
 for more information.
 .Pp
 .Dl $ nc -x10.2.3.4:8080 -Xconnect host.example.com 42
+.Pp
+The same example again, this time enabling proxy authentication with username
+.Dq ruser
+if the proxy requires it:
+.Pp
+.Dl $ nc -x10.2.3.4:8080 -Xconnect -Pruser host.example.com 42
 .Sh SEE ALSO
 .Xr cat 1 ,
 .Xr ssh 1
diff --git a/usr.bin/nc/netcat.c b/usr.bin/nc/netcat.c
index a10a8954c52..cec87ff7316 100644
--- a/usr.bin/nc/netcat.c
+++ b/usr.bin/nc/netcat.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: netcat.c,v 1.85 2006/01/20 00:01:20 millert Exp $ */
+/* $OpenBSD: netcat.c,v 1.86 2006/01/25 23:21:37 djm Exp $ */
 /*
  * Copyright (c) 2001 Eric Jackson <ericj@monkey.org>
  *
@@ -70,6 +70,7 @@ int	jflag;					/* use jumbo frames if we can */
 int	kflag;					/* More than one connect */
 int	lflag;					/* Bind to local port */
 int	nflag;					/* Don't do name look up */
+char   *Pflag;					/* Proxy username */
 char   *pflag;					/* Localport flag */
 int	rflag;					/* Random ports flag */
 char   *sflag;					/* Source Address */
@@ -92,8 +93,8 @@ void	help(void);
 int	local_listen(char *, char *, struct addrinfo);
 void	readwrite(int);
 int	remote_connect(const char *, const char *, struct addrinfo);
-int	socks_connect(const char *, const char *, struct addrinfo, const char *, const char *,
-	struct addrinfo, int);
+int	socks_connect(const char *, const char *, struct addrinfo,
+	    const char *, const char *, struct addrinfo, int, const char *);
 int	udptest(int);
 int	unix_connect(char *);
 int	unix_listen(char *);
@@ -123,7 +124,7 @@ main(int argc, char *argv[])
 	sv = NULL;
 
 	while ((ch = getopt(argc, argv,
-	    "46Ddhi:jklnp:rSs:tT:Uuvw:X:x:z")) != -1) {
+	    "46Ddhi:jklnP:p:rSs:tT:Uuvw:X:x:z")) != -1) {
 		switch (ch) {
 		case '4':
 			family = AF_INET;
@@ -167,6 +168,9 @@ main(int argc, char *argv[])
 		case 'n':
 			nflag = 1;
 			break;
+		case 'P':
+			Pflag = optarg;
+			break;
 		case 'p':
 			pflag = optarg;
 			break;
@@ -354,7 +358,8 @@ main(int argc, char *argv[])
 
 			if (xflag)
 				s = socks_connect(host, portlist[i], hints,
-				    proxyhost, proxyport, proxyhints, socksv);
+				    proxyhost, proxyport, proxyhints, socksv,
+				    Pflag);
 			else
 				s = remote_connect(host, portlist[i], hints);
 
@@ -818,6 +823,7 @@ help(void)
 	\t-k		Keep inbound sockets open for multiple connects\n\
 	\t-l		Listen mode, for inbound connects\n\
 	\t-n		Suppress name/port resolutions\n\
+	\t-P proxyuser\tUsername for proxy authentication\n\
 	\t-p port\t	Specify local port for remote connects\n\
 	\t-r		Randomize remote ports\n\
 	\t-S		Enable the TCP MD5 signature option\n\
diff --git a/usr.bin/nc/socks.c b/usr.bin/nc/socks.c
index de61439400d..daed99712e3 100644
--- a/usr.bin/nc/socks.c
+++ b/usr.bin/nc/socks.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: socks.c,v 1.15 2005/05/24 20:13:28 avsm Exp $	*/
+/*	$OpenBSD: socks.c,v 1.16 2006/01/25 23:21:37 djm Exp $	*/
 
 /*
  * Copyright (c) 1999 Niklas Hallqvist.  All rights reserved.
@@ -37,6 +37,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <resolv.h>
+#include <readpassphrase.h>
 #include "atomicio.h"
 
 #define SOCKS_PORT	"1080"
@@ -52,9 +54,9 @@
 #define SOCKS_IPV6	4
 
 int	remote_connect(const char *, const char *, struct addrinfo);
-int	socks_connect(const char *host, const char *port, struct addrinfo hints,
-	    const char *proxyhost, const char *proxyport, struct addrinfo proxyhints,
-	    int socksv);
+int	socks_connect(const char *, const char *, struct addrinfo,
+	    const char *, const char *, struct addrinfo, int,
+	    const char *);
 
 static int
 decode_addrport(const char *h, const char *p, struct sockaddr *addr,
@@ -107,13 +109,26 @@ proxy_read_line(int fd, char *buf, size_t bufsz)
 	return (off);
 }
 
+static const char *
+getproxypass(const char *proxyuser, const char *proxyhost)
+{
+	char prompt[512];
+	static char pw[256];
+
+	snprintf(prompt, sizeof(prompt), "Proxy password for %s@%s: ",
+	   proxyuser, proxyhost);
+	if (readpassphrase(prompt, pw, sizeof(pw), RPP_REQUIRE_TTY) == NULL)
+		errx(1, "Unable to read proxy passphrase");
+	return (pw);
+}
+
 int
 socks_connect(const char *host, const char *port,
     struct addrinfo hints __attribute__ ((__unused__)),
     const char *proxyhost, const char *proxyport, struct addrinfo proxyhints,
-    int socksv)
+    int socksv, const char *proxyuser)
 {
-	int proxyfd, r;
+	int proxyfd, r, authretry = 0;
 	size_t hlen, wlen;
 	unsigned char buf[1024];
 	size_t cnt;
@@ -121,21 +136,26 @@ socks_connect(const char *host, const char *port,
 	struct sockaddr_in *in4 = (struct sockaddr_in *)&addr;
 	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&addr;
 	in_port_t serverport;
+	const char *proxypass = NULL;
 
 	if (proxyport == NULL)
 		proxyport = (socksv == -1) ? HTTP_PROXY_PORT : SOCKS_PORT;
 
-	proxyfd = remote_connect(proxyhost, proxyport, proxyhints);
-
-	if (proxyfd < 0)
-		return (-1);
-
 	/* Abuse API to lookup port */
 	if (decode_addrport("0.0.0.0", port, (struct sockaddr *)&addr,
 	    sizeof(addr), 1, 1) == -1)
 		errx(1, "unknown port \"%.64s\"", port);
 	serverport = in4->sin_port;
 
+ again:
+	if (authretry++ > 3)
+		errx(1, "Too many authentication failures");
+
+	proxyfd = remote_connect(proxyhost, proxyport, proxyhints);
+
+	if (proxyfd < 0)
+		return (-1);
+
 	if (socksv == 5) {
 		if (decode_addrport(host, port, (struct sockaddr *)&addr,
 		    sizeof(addr), 0, 1) == -1)
@@ -239,11 +259,11 @@ socks_connect(const char *host, const char *port,
 		/* Try to be sane about numeric IPv6 addresses */
 		if (strchr(host, ':') != NULL) {
 			r = snprintf(buf, sizeof(buf),
-			    "CONNECT [%s]:%d HTTP/1.0\r\n\r\n",
+			    "CONNECT [%s]:%d HTTP/1.0\r\n",
 			    host, ntohs(serverport));
 		} else {
 			r = snprintf(buf, sizeof(buf),
-			    "CONNECT %s:%d HTTP/1.0\r\n\r\n",
+			    "CONNECT %s:%d HTTP/1.0\r\n",
 			    host, ntohs(serverport));
 		}
 		if (r == -1 || (size_t)r >= sizeof(buf))
@@ -254,15 +274,50 @@ socks_connect(const char *host, const char *port,
 		if (cnt != r)
 			err(1, "write failed (%d/%d)", cnt, r);
 
-		/* Read reply */
+		if (authretry > 1) {
+			char resp[1024];
+
+			proxypass = getproxypass(proxyuser, proxyhost);
+			r = snprintf(buf, sizeof(buf), "%s:%s",
+			    proxyuser, proxypass);
+			if (r == -1 || (size_t)r >= sizeof(buf) ||
+			    b64_ntop(buf, strlen(buf), resp,
+			    sizeof(resp)) == -1)
+				errx(1, "Proxy username/password too long");
+			r = snprintf(buf, sizeof(buf), "Proxy-Authorization: "
+			    "Basic %s\r\n", resp);
+			if (r == -1 || (size_t)r >= sizeof(buf))
+				errx(1, "Proxy auth response too long");
+			r = strlen(buf);
+			if ((cnt = atomicio(vwrite, proxyfd, buf, r)) != r)
+				err(1, "write failed (%d/%d)", cnt, r);
+		}
+
+		/* Terminate headers */
+		if ((r = atomicio(vwrite, proxyfd, "\r\n", 2)) != 2)
+			err(1, "write failed (2/%d)", r);
+
+		/* Read status reply */
+		proxy_read_line(proxyfd, buf, sizeof(buf));
+		if (proxyuser != NULL &&
+		    strncmp(buf, "HTTP/1.0 407 ", 12) == 0) {
+			if (authretry > 1) {
+				fprintf(stderr, "Proxy authentication "
+				    "failed\n");
+			}
+			close(proxyfd);
+			goto again;
+		} else if (strncmp(buf, "HTTP/1.0 200 ", 12) != 0)
+			errx(1, "Proxy error: \"%s\"", buf);
+
+		/* Headers continue until we hit an empty line */
 		for (r = 0; r < HTTP_MAXHDRS; r++) {
 			proxy_read_line(proxyfd, buf, sizeof(buf));
-			if (r == 0 && strncmp(buf, "HTTP/1.0 200 ", 12) != 0)
-				errx(1, "Proxy error: \"%s\"", buf);
-			/* Discard headers until we hit an empty line */
 			if (*buf == '\0')
 				break;
 		}
+		if (*buf != '\0')
+			errx(1, "Too many proxy headers received");
 	} else
 		errx(1, "Unknown proxy protocol %d", socksv);