Add TLS suppport to nc. Provides a useful little test and script tool.

ok jsing@ bluhm@

3 files changed, 346 insertions, 45 deletions

diff --git a/src/usr.bin/nc/Makefile b/src/usr.bin/nc/Makefile
index 150f8295bd..5f20c40cf7 100644
--- a/src/usr.bin/nc/Makefile
+++ b/src/usr.bin/nc/Makefile
@@ -1,6 +1,8 @@
-#       $OpenBSD: Makefile,v 1.6 2001/09/02 18:45:41 jakob Exp $
+#       $OpenBSD: Makefile,v 1.7 2015/09/11 21:07:01 beck Exp $
 
 PROG=   nc
 SRCS=   netcat.c atomicio.c socks.c
+LDADD+= -ltls -lssl -lcrypto
+DPADD+=  ${LIBTLS} ${LIBSSL} ${LIBCRYPTO}
 
 .include <bsd.prog.mk>
diff --git a/src/usr.bin/nc/nc.1 b/src/usr.bin/nc/nc.1
index d83cb5ca8d..8cb96e8734 100644
--- a/src/usr.bin/nc/nc.1
+++ b/src/usr.bin/nc/nc.1
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: nc.1,v 1.68 2015/03/26 10:35:04 tobias Exp $
+.\"     $OpenBSD: nc.1,v 1.69 2015/09/11 21:07:01 beck Exp $
 .\"
 .\" Copyright (c) 1996 David Sacerdote
 .\" All rights reserved.
@@ -25,7 +25,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: March 26 2015 $
+.Dd $Mdocdate: September 11 2015 $
 .Dt NC 1
 .Os
 .Sh NAME
@@ -41,7 +41,7 @@
 .Op Fl P Ar proxy_username
 .Op Fl p Ar source_port
 .Op Fl s Ar source
-.Op Fl T Ar toskeyword
+.Op Fl T Ar keyword
 .Op Fl V Ar rtable
 .Op Fl w Ar timeout
 .Op Fl X Ar proxy_protocol
@@ -98,10 +98,18 @@ to use IPv4 addresses only.
 Forces
 .Nm
 to use IPv6 addresses only.
+.It Fl C Ar certificate_filename
+Specifies the filename from which the public key part of the TLS
+certificate is loaded, in PEM format. May only be used with TLS.
+.It Fl c
+If using a TCP socket to connect or listen, use TLS. Illegal if not using TCP sockets.
 .It Fl D
 Enable debugging on the socket.
 .It Fl d
 Do not attempt to read from stdin.
+.It Fl e Ar name
+specify the name that must be present in the peer certificate when using TLS.
+Illegal if not using TLS.
 .It Fl F
 Pass the first connected socket using
 .Xr sendmsg 2
@@ -117,6 +125,11 @@ using the
 .Xr ssh_config 5
 .Cm ProxyUseFdpass
 option).
+.It Fl H Ar hash_string
+Specifies the required hash string of the peer certificate when using TLS.
+The string format required is that used by
+.Xr tls_peer_cert_hash 3 .
+Illegal if not using TLS, and may not be used with -T noverify.
 .It Fl h
 Prints out
 .Nm
@@ -126,6 +139,9 @@ Specifies the size of the TCP receive buffer.
 .It Fl i Ar interval
 Specifies a delay time interval between lines of text sent and received.
 Also causes a delay time between connections to multiple ports.
+.It Fl K Ar key_filename
+Specifies the filename from which the private key
+is loaded in PEM format. May only be used with TLS.
 .It Fl k
 Forces
 .Nm
@@ -172,6 +188,11 @@ should use, subject to privilege restrictions and availability.
 It is an error to use this option in conjunction with the
 .Fl l
 option.
+.It Fl R Ar CA_filename
+Specifies the filename from which the root CA bundle for Certificate
+verification is loaded in pem format. Illegal if not using TLS.
+Default value is
+.Pa /etc/ssl/cert.pem .
 .It Fl r
 Specifies that source and/or destination ports should be chosen randomly
 instead of sequentially within a range or in the order that the system
@@ -187,9 +208,22 @@ to create and use so that datagrams can be received.
 It is an error to use this option in conjunction with the
 .Fl l
 option.
-.It Fl T Ar toskeyword
-Change IPv4 TOS value.
-.Ar toskeyword
+.It Fl T Ar keyword
+Change IPv4 TOS value or TLS options.
+For TLS options
+.Ar keyword
+may be one of
+.Ar tlslegacy ,
+which allows legacy TLS protocols,
+.Ar noverify ,
+which disables certificate verification
+.Ar noname ,
+which disables certificate name checking, or
+.Ar clientcert,
+which requires a client certificate on incoming connections .
+It is illegal to specify TLS options if not using TLS.
+For IPv4 TOS value
+.Ar keyword
 may be one of
 .Ar critical ,
 .Ar inetcontrol ,
@@ -429,6 +463,11 @@ the source port, with a timeout of 5 seconds:
 .Pp
 .Dl $ nc -p 31337 -w 5 host.example.com 42
 .Pp
+Open a TCP connection to port 443 of www.google.ca, and negotiate
+TLS. Check for a different name in the certificate for validation.
+.Pp
+.Dl $  nc -v -c -e adsf.au.doubleclick.net www.google.ca 443
+.Pp
 Open a UDP connection to port 53 of host.example.com:
 .Pp
 .Dl $ nc -u host.example.com 53
diff --git a/src/usr.bin/nc/netcat.c b/src/usr.bin/nc/netcat.c
index ce613cd75d..3909f70817 100644
--- a/src/usr.bin/nc/netcat.c
+++ b/src/usr.bin/nc/netcat.c
@@ -1,6 +1,7 @@
-/* $OpenBSD: netcat.c,v 1.132 2015/09/08 17:28:47 bluhm Exp $ */
+/* $OpenBSD: netcat.c,v 1.133 2015/09/11 21:07:01 beck Exp $ */
 /*
  * Copyright (c) 2001 Eric Jackson <ericj@monkey.org>
+ * Copyright (c) 2015 Bob Beck.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -54,6 +55,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <tls.h>
 #include "atomicio.h"
 
 #ifndef SUN_LEN
@@ -70,6 +72,12 @@
 #define POLL_NETIN 2
 #define POLL_STDOUT 3
 #define BUFSIZE 16384
+#define DEFAULT_CA_FILE "/etc/ssl/cert.pem"
+
+#define TLS_LEGACY      (1 << 1)
+#define TLS_NOVERIFY    (1 << 2)
+#define TLS_NONAME      (1 << 3)
+#define TLS_CCERT       (1 << 4)
 
 /* Command Line Options */
 int     dflag;                                  /* detached, no stdin */
@@ -95,6 +103,16 @@ int	Sflag;					/* TCP MD5 signature option */
 int     Tflag = -1;                             /* IP Type of Service */
 int     rtableid = -1;
 
+int     usetls;                                 /* use TLS */
+char    *Cflag;                                 /* Public cert file */
+char    *Kflag;                                 /* Private key file */
+char    *Rflag = DEFAULT_CA_FILE;               /* Root CA file */
+int     tls_cachanged;                          /* Using non-default CA file */
+int     TLSopt;                                 /* TLS options */
+char    *tls_expectname;                        /* required name in peer cert */
+char    *tls_peerhash;                          /* hash of peer cert */
+char    *tls_expecthash;                        /* required hash of peer cert */
+
 int timeout = -1;
 int family = AF_UNSPEC;
 char *portlist[PORT_MAX+1];
@@ -104,7 +122,7 @@ void	atelnet(int, unsigned char *, unsigned int);
 void    build_ports(char *);
 void    help(void);
 int     local_listen(char *, char *, struct addrinfo);
-void    readwrite(int);
+void    readwrite(int, struct tls *);
 void    fdpass(int nfd) __attribute__((noreturn));
 int     remote_connect(const char *, const char *, struct addrinfo);
 int     timeout_connect(int, const struct sockaddr *, socklen_t);
@@ -116,10 +134,14 @@ int	unix_connect(char *);
 int     unix_listen(char *);
 void    set_common_sockopts(int, int);
 int     map_tos(char *, int *);
+int     map_tls(char *, int *);
 void    report_connect(const struct sockaddr *, socklen_t);
+void    report_tls(struct tls * tls_ctx, char * host, char *tls_expectname);
 void    usage(int);
-ssize_t drainbuf(int, unsigned char *, size_t *);
-ssize_t fillbuf(int, unsigned char *, size_t *);
+ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *);
+ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *);
+void    tls_setup_client(struct tls *, int, char *);
+struct tls * tls_setup_server(struct tls *, int, char *);
 
 int
 main(int argc, char *argv[])
@@ -134,6 +156,8 @@ main(int argc, char *argv[])
         const char *errstr, *proxyhost = "", *proxyport = NULL;
         struct addrinfo proxyhints;
         char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE];
+        struct tls_config *tls_cfg = NULL;
+        struct tls *tls_ctx = NULL;
 
         ret = 1;
         s = 0;
@@ -145,7 +169,7 @@ main(int argc, char *argv[])
         signal(SIGPIPE, SIG_IGN);
 
         while ((ch = getopt(argc, argv,
-            "46DdFhI:i:klNnO:P:p:rSs:tT:UuV:vw:X:x:z")) != -1) {
+            "46C:cDde:FH:hI:i:K:klNnO:P:p:R:rSs:T:tUuV:vw:X:x:z")) != -1) {
                 switch (ch) {
                 case '4':
                         family = AF_INET;
@@ -166,12 +190,24 @@ main(int argc, char *argv[])
                         else
                                 errx(1, "unsupported proxy protocol");
                         break;
+                case 'C':
+                        Cflag = optarg;
+                        break;
+                case 'c':
+                        usetls = 1;
+                        break;
                 case 'd':
                         dflag = 1;
                         break;
+                case 'e':
+                        tls_expectname = optarg;
+                        break;
                 case 'F':
                         Fflag = 1;
                         break;
+                case 'H':
+                        tls_expecthash = optarg;
+                        break;
                 case 'h':
                         help();
                         break;
@@ -180,6 +216,9 @@ main(int argc, char *argv[])
                         if (errstr)
                                 errx(1, "interval %s: %s", errstr, optarg);
                         break;
+                case 'K':
+                        Kflag = optarg;
+                        break;
                 case 'k':
                         kflag = 1;
                         break;
@@ -198,6 +237,10 @@ main(int argc, char *argv[])
                 case 'p':
                         pflag = optarg;
                         break;
+                case 'R':
+                        tls_cachanged = 1;
+                        Rflag = optarg;
+                        break;
                 case 'r':
                         rflag = 1;
                         break;
@@ -256,6 +299,8 @@ main(int argc, char *argv[])
                         errno = 0;
                         if (map_tos(optarg, &Tflag))
                                 break;
+                        if (map_tls(optarg, &TLSopt))
+                                break;
                         if (strlen(optarg) > 1 && optarg[0] == '0' &&
                             optarg[1] == 'x')
                                 Tflag = (int)strtol(optarg, NULL, 16);
@@ -263,7 +308,7 @@ main(int argc, char *argv[])
                                 Tflag = (int)strtonum(optarg, 0, 255,
                                     &errstr);
                         if (Tflag < 0 || Tflag > 255 || errstr || errno)
-                                errx(1, "illegal tos value %s", optarg);
+                                errx(1, "illegal tos/tls value %s", optarg);
                         break;
                 default:
                         usage(1);
@@ -295,6 +340,22 @@ main(int argc, char *argv[])
                 errx(1, "cannot use -z and -l");
         if (!lflag && kflag)
                 errx(1, "must use -l with -k");
+        if (uflag && usetls)
+                errx(1, "cannot use -c and -u");
+        if ((family == AF_UNIX) && usetls)
+                errx(1, "cannot use -c and -U");
+        if (TLSopt && !usetls)
+                errx(1, "you must specify -c to use TLS options");
+        if (Cflag && !usetls)
+                errx(1, "you must specify -c to use -C");
+        if (Kflag && !usetls)
+                errx(1, "you must specify -c to use -K");
+        if (tls_cachanged && !usetls)
+                errx(1, "you must specify -c to use -R");
+        if (tls_expecthash && !usetls)
+                errx(1, "you must specify -c to use -H");
+        if (tls_expectname && !usetls)
+                errx(1, "you must specify -c to use -e");
 
         /* Get name of temporary socket for unix datagram client */
         if ((family == AF_UNIX) && uflag && !lflag) {
@@ -347,7 +408,34 @@ main(int argc, char *argv[])
                         proxyhints.ai_flags |= AI_NUMERICHOST;
         }
 
+        if (usetls) {
+                if (tls_init() == -1)
+                        errx(1, "unable to initialize TLS");
+                if ((tls_cfg = tls_config_new()) == NULL)
+                        errx(1, "unable to allocate TLS config");
+                if (Cflag && (tls_config_set_cert_file(tls_cfg, Cflag) == -1))
+                        errx(1, "unable to set TLS certificate file %s", Cflag);
+                if (Kflag && (tls_config_set_key_file(tls_cfg, Kflag) == -1))
+                        errx(1, "unable to set TLS key file %s", Kflag);
+                if (Rflag && (tls_config_set_ca_file(tls_cfg, Rflag) == -1))
+                        errx(1, "unable to set root CA file %s", Rflag);
+                if (TLSopt & TLS_LEGACY) {
+                        tls_config_set_protocols(tls_cfg, TLS_PROTOCOLS_ALL);
+                        tls_config_set_ciphers(tls_cfg, "legacy");
+                }
+                if (!lflag && (TLSopt & TLS_CCERT))
+                        errx(1, "clientcert is only valid with -l");
+                if (TLSopt & TLS_NONAME)
+                        tls_config_insecure_noverifyname(tls_cfg);
+                if (TLSopt & TLS_NOVERIFY) {
+                        if (tls_expecthash != NULL)
+                                errx(1, "-H and -T noverify may not be used"
+                                    "together");
+                        tls_config_insecure_noverifycert(tls_cfg);
+                }
+        }
         if (lflag) {
+                struct tls *tls_cctx = NULL;
                 int connfd;
                 ret = 0;
 
@@ -358,6 +446,14 @@ main(int argc, char *argv[])
                                 s = unix_listen(host);
                 }
 
+                if (usetls) {
+                        tls_config_verify_client_optional(tls_cfg);
+                        if ((tls_ctx = tls_server()) == NULL)
+                                errx(1, "tls server creation failed");
+                        if (tls_configure(tls_ctx, tls_cfg) == -1)
+                                errx(1, "tls configuration failed (%s)",
+                                    tls_error(tls_ctx));
+                }
                 /* Allow only one connection at a time, but stay alive. */
                 for (;;) {
                         if (family != AF_UNIX)
@@ -369,7 +465,7 @@ main(int argc, char *argv[])
                          * receive datagrams from multiple socket pairs.
                          */
                         if (uflag && kflag)
-                                readwrite(s);
+                                readwrite(s, NULL);
                         /*
                          * For UDP and not -k, we will use recvfrom() initially
                          * to wait for a caller, then use the regular functions
@@ -394,7 +490,7 @@ main(int argc, char *argv[])
                                 if (vflag)
                                         report_connect((struct sockaddr *)&z, len);
 
-                                readwrite(s);
+                                readwrite(s, NULL);
                         } else {
                                 len = sizeof(cliaddr);
                                 connfd = accept4(s, (struct sockaddr *)&cliaddr,
@@ -405,11 +501,23 @@ main(int argc, char *argv[])
                                 }
                                 if (vflag)
                                         report_connect((struct sockaddr *)&cliaddr, len);
-
-                                readwrite(connfd);
+                                if ((usetls) &&
+                                    (tls_cctx = tls_setup_server(tls_ctx, connfd,
+                                        host)))
+                                        readwrite(connfd, tls_cctx);
+                                if (!usetls)
+                                        readwrite(connfd, NULL);
+                                if (tls_cctx) {
+                                        int i;
+                                        do {
+                                                i = tls_close(tls_cctx);
+                                        } while (i == TLS_WANT_POLLIN ||
+                                            i == TLS_WANT_POLLOUT);
+                                        tls_free(tls_cctx);
+                                        tls_cctx = NULL;
+                                }
                                 close(connfd);
                         }
-
                         if (family != AF_UNIX)
                                 close(s);
                         else if (uflag) {
@@ -424,7 +532,7 @@ main(int argc, char *argv[])
                 ret = 0;
 
                 if ((s = unix_connect(host)) > 0 && !zflag) {
-                        readwrite(s);
+                        readwrite(s, NULL);
                         close(s);
                 } else
                         ret = 1;
@@ -444,6 +552,13 @@ main(int argc, char *argv[])
                         if (s)
                                 close(s);
 
+                        if (usetls) {
+                                if ((tls_ctx = tls_client()) == NULL)
+                                        errx(1, "tls client creation failed");
+                                if (tls_configure(tls_ctx, tls_cfg) == -1)
+                                        errx(1, "tls configuration failed (%s)",
+                                            tls_error(tls_ctx));
+                        }
                         if (xflag)
                                 s = socks_connect(host, portlist[i], hints,
                                     proxyhost, proxyport, proxyhints, socksv,
@@ -481,14 +596,30 @@ main(int argc, char *argv[])
                         }
                         if (Fflag)
                                 fdpass(s);
-                        else if (!zflag)
-                                readwrite(s);
+                        else {
+                                if (usetls)
+                                        tls_setup_client(tls_ctx, s, host);
+                                if (!zflag)
+                                        readwrite(s, tls_ctx);
+                                if (tls_ctx) {
+                                        int j;
+                                        do {
+                                                j = tls_close(tls_ctx);
+                                        } while (j == TLS_WANT_POLLIN ||
+                                            j == TLS_WANT_POLLOUT);
+                                        tls_free(tls_ctx);
+                                        tls_ctx = NULL;
+                                }
+                        }
                 }
         }
 
         if (s)
                 close(s);
 
+        free(tls_peerhash);
+        tls_config_free(tls_cfg);
+
         exit(ret);
 }
 
@@ -524,6 +655,67 @@ unix_bind(char *path)
         return (s);
 }
 
+void
+tls_setup_client(struct tls *tls_ctx, int s, char *host)
+
+{
+        int i;
+        if (tls_connect_socket(tls_ctx, s,
+                tls_expectname ? tls_expectname : host) == -1) {
+                errx(1, "tls connection failed (%s)",
+                    tls_error(tls_ctx));
+        }
+        do {
+                if ((i = tls_handshake(tls_ctx)) == -1)
+                        errx(1, "tls handshake failed (%s)",
+                            tls_error(tls_ctx));
+        } while (i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT);
+        if (tls_peer_cert_hash(tls_ctx, &tls_peerhash) == -1)
+                errx(1, "hash of peer certificate failed");
+        if (vflag)
+                report_tls(tls_ctx, host, tls_expectname);
+        if (tls_expecthash && tls_peerhash &&
+            strcmp(tls_expecthash, tls_peerhash) != 0)
+                errx(1, "peer certificate is not %s", tls_expecthash);
+}
+struct tls *
+tls_setup_server(struct tls *tls_ctx, int connfd, char *host)
+{
+        struct tls *tls_cctx;
+        if (tls_accept_socket(tls_ctx, &tls_cctx,
+                connfd) == -1) {
+                warnx("tls accept failed (%s)",
+                    tls_error(tls_ctx));
+                tls_cctx = NULL;
+        } else {
+                int i;
+                do {
+                        if ((i = tls_handshake(tls_cctx)) == -1)
+                                warnx("tls handshake failed (%s)",
+                                    tls_error(tls_cctx));
+                } while(i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT);
+        }
+        if (tls_cctx) {
+                int gotcert = tls_peer_cert_provided(tls_cctx);
+                if (gotcert && tls_peer_cert_hash(tls_cctx, &tls_peerhash) == -1)
+                        warn("hash of peer certificate failed");
+                if (vflag && gotcert)
+                        report_tls(tls_cctx, host, tls_expectname);
+                if ((TLSopt & TLS_CCERT) && !gotcert)
+                        warnx("No client certificate provided");
+                else if (gotcert && tls_peerhash && tls_expecthash &&
+                    strcmp(tls_expecthash, tls_peerhash) != 0)
+                        warnx("peer certificate is not %s", tls_expecthash);
+                else if (gotcert && tls_expectname &&
+                    (! tls_peer_cert_contains_name(tls_cctx, tls_expectname)))
+                        warnx("name (%s) not found in client cert",
+                            tls_expectname);
+                else {
+                        return tls_cctx;
+                }
+        }
+        return NULL;
+}
 /*
  * unix_connect()
  * Returns a socket connected to a local unix socket. Returns -1 on failure.
@@ -731,7 +923,7 @@ local_listen(char *host, char *port, struct addrinfo hints)
  * Loop that polls on the network file descriptor and stdin.
  */
 void
-readwrite(int net_fd)
+readwrite(int net_fd, struct tls *tls_ctx)
 {
         struct pollfd pfd[4];
         int stdin_fd = STDIN_FILENO;
@@ -839,9 +1031,12 @@ readwrite(int net_fd)
                 /* try to read from stdin */
                 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) {
                         ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf,
-                            &stdinbufpos);
-                        /* error or eof on stdin - remove from pfd */
-                        if (ret == 0 || ret == -1)
+                            &stdinbufpos, NULL);
+                        if (ret == TLS_WANT_POLLIN)
+                                pfd[POLL_STDIN].events = POLLIN;
+                        else if (ret == TLS_WANT_POLLOUT)
+                                pfd[POLL_STDIN].events = POLLOUT;
+                        else if (ret == 0 || ret == -1)
                                 pfd[POLL_STDIN].fd = -1;
                         /* read something - poll net out */
                         if (stdinbufpos > 0)
@@ -853,8 +1048,12 @@ readwrite(int net_fd)
                 /* try to write to network */
                 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) {
                         ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf,
-                            &stdinbufpos);
-                        if (ret == -1)
+                            &stdinbufpos, tls_ctx);
+                        if (ret == TLS_WANT_POLLIN)
+                                pfd[POLL_NETOUT].events = POLLIN;
+                        else if (ret == TLS_WANT_POLLOUT)
+                                pfd[POLL_NETOUT].events = POLLOUT;
+                        else if (ret == -1)
                                 pfd[POLL_NETOUT].fd = -1;
                         /* buffer empty - remove self from polling */
                         if (stdinbufpos == 0)
@@ -866,8 +1065,12 @@ readwrite(int net_fd)
                 /* try to read from network */
                 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) {
                         ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf,
-                            &netinbufpos);
-                        if (ret == -1)
+                            &netinbufpos, tls_ctx);
+                        if (ret == TLS_WANT_POLLIN)
+                                pfd[POLL_NETIN].events = POLLIN;
+                        else if (ret == TLS_WANT_POLLOUT)
+                                pfd[POLL_NETIN].events = POLLOUT;
+                        else if (ret == -1)
                                 pfd[POLL_NETIN].fd = -1;
                         /* eof on net in - remove from pfd */
                         if (ret == 0) {
@@ -888,8 +1091,12 @@ readwrite(int net_fd)
                 /* try to write to stdout */
                 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) {
                         ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf,
-                            &netinbufpos);
-                        if (ret == -1)
+                            &netinbufpos, NULL);
+                        if (ret == TLS_WANT_POLLIN)
+                                pfd[POLL_STDOUT].events = POLLIN;
+                        else if (ret == TLS_WANT_POLLOUT)
+                                pfd[POLL_STDOUT].events = POLLOUT;
+                        else if (ret == -1)
                                 pfd[POLL_STDOUT].fd = -1;
                         /* buffer empty - remove self from polling */
                         if (netinbufpos == 0)
@@ -913,15 +1120,19 @@ readwrite(int net_fd)
 }
 
 ssize_t
-drainbuf(int fd, unsigned char *buf, size_t *bufpos)
+drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls)
 {
         ssize_t n;
         ssize_t adjust;
 
-        n = write(fd, buf, *bufpos);
-        /* don't treat EAGAIN, EINTR as error */
-        if (n == -1 && (errno == EAGAIN || errno == EINTR))
-                n = -2;
+        if (tls)
+                n = tls_write(tls, buf, *bufpos);
+        else {
+                n = write(fd, buf, *bufpos);
+                /* don't treat EAGAIN, EINTR as error */
+                if (n == -1 && (errno == EAGAIN || errno == EINTR))
+                        n = TLS_WANT_POLLOUT;
+        }
         if (n <= 0)
                 return n;
         /* adjust buffer */
@@ -934,15 +1145,19 @@ drainbuf(int fd, unsigned char *buf, size_t *bufpos)
 
 
 ssize_t
-fillbuf(int fd, unsigned char *buf, size_t *bufpos)
+fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls)
 {
         size_t num = BUFSIZE - *bufpos;
         ssize_t n;
 
-        n = read(fd, buf + *bufpos, num);
-        /* don't treat EAGAIN, EINTR as error */
-        if (n == -1 && (errno == EAGAIN || errno == EINTR))
-                n = -2;
+        if (tls)
+                n = tls_read(tls, buf + *bufpos, num);
+        else {
+                n = read(fd, buf + *bufpos, num);
+                /* don't treat EAGAIN, EINTR as error */
+                if (n == -1 && (errno == EAGAIN || errno == EINTR))
+                        n = TLS_WANT_POLLIN;
+        }
         if (n <= 0)
                 return n;
         *bufpos += n;
@@ -1209,6 +1424,49 @@ map_tos(char *s, int *val)
         return (0);
 }
 
+int
+map_tls(char *s, int *val)
+{
+        const struct tlskeywords {
+                const char      *keyword;
+                int              val;
+        } *t, tlskeywords[] = {
+                { "tlslegacy",          TLS_LEGACY },
+                { "noverify",           TLS_NOVERIFY },
+                { "noname",             TLS_NONAME },
+                { "clientcert",         TLS_CCERT},
+                { NULL,                 -1 },
+        };
+
+        for (t = tlskeywords; t->keyword != NULL; t++) {
+                if (strcmp(s, t->keyword) == 0) {
+                        *val |= t->val;
+                        return (1);
+                }
+        }
+        return (0);
+}
+
+void
+report_tls(struct tls * tls_ctx, char * host, char *tls_expectname)
+{
+        char *subject = NULL, *issuer = NULL;
+        if (tls_peer_cert_subject(tls_ctx, &subject) == -1)
+                errx(1, "unable to get certificate subject");
+        if (tls_peer_cert_issuer(tls_ctx, &issuer) == -1)
+                errx(1, "unable to get certificate issuer");
+        fprintf(stderr, "TLS handshake completed with %s\n", host);
+        fprintf(stderr, "Peer name %s\n",
+            tls_expectname ? tls_expectname : host);
+        if (subject)
+                fprintf(stderr, "Subject: %s\n", subject);
+        if (issuer)
+                fprintf(stderr, "Issuer: %s\n", issuer);
+        if (tls_peerhash)
+                fprintf(stderr, "Cert Hash: %s\n", tls_peerhash);
+        free(subject);
+        free(issuer);
+}
 void
 report_connect(const struct sockaddr *sa, socklen_t salen)
 {
@@ -1276,10 +1534,12 @@ void
 usage(int ret)
 {
         fprintf(stderr,
-            "usage: nc [-46DdFhklNnrStUuvz] [-I length] [-i interval] [-O length]\n"
-            "\t  [-P proxy_username] [-p source_port] [-s source] [-T toskeyword]\n"
-            "\t  [-V rtable] [-w timeout] [-X proxy_protocol]\n"
-            "\t  [-x proxy_address[:port]] [destination] [port]\n");
+            "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] \n"
+            "\t  [-I length] [-i interval] [-H hash] [-K keyfile] [-O length]\n"
+            "\t  [-P proxy_username] [-p source_port] [-R cafile] [-s source]\n"
+            "\t  [-T tls|toskeyword] [-V rtable] [-w timeout]\n"
+            "\t  [-X proxy_protocol] [-x proxy_address[:port]]\n"
+            "\t  [destination] [port]\n");
         if (ret)
                 exit(1);
 }