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-rw-r--r--doc/examples/tlsproxy/LICENSE21
-rw-r--r--doc/examples/tlsproxy/README.md53
-rw-r--r--doc/examples/tlsproxy/buffer.c228
-rw-r--r--doc/examples/tlsproxy/buffer.h45
-rw-r--r--doc/examples/tlsproxy/crypto-gnutls.c585
-rw-r--r--doc/examples/tlsproxy/crypto-gnutls.h43
-rw-r--r--doc/examples/tlsproxy/tlsproxy.c464
7 files changed, 1439 insertions, 0 deletions
diff --git a/doc/examples/tlsproxy/LICENSE b/doc/examples/tlsproxy/LICENSE
new file mode 100644
index 0000000..43f5934
--- /dev/null
+++ b/doc/examples/tlsproxy/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2016 Wrymouth Innovation Ltd
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
diff --git a/doc/examples/tlsproxy/README.md b/doc/examples/tlsproxy/README.md
new file mode 100644
index 0000000..3c7a17f
--- /dev/null
+++ b/doc/examples/tlsproxy/README.md
@@ -0,0 +1,53 @@
+tlsproxy
+========
+
+`tlsproxy` is a TLS proxy written with GnuTLS. It is mostly designed as an
+example of how to use asynchronous (non-blocking) I/O with GnuTLS. More
+accurately, it was designed so I could learn how to do it. I think I've
+got it right.
+
+To that end, it's been divided up as follows:
+
+* `crypto.c` does all the crypto, and `tlssession_mainloop()` does the hard work.
+* `buffer.c` provides ring buffer support.
+* `tlsproxy.c` deals with command line options and connecting sockets.
+
+It can be used in two modes:
+
+* Client mode (default). Listens on an unencrypted port, connects to
+ an encrypted port.
+* Server mode (run with `-s`). Listens on an encrypted port, connects to
+ an unencrypted port.
+
+Usage
+=====
+
+```
+tlsproxy
+
+Usage:
+ tlsproxy [OPTIONS]
+
+A TLS client or server proxy
+
+Options:
+ -c, --connect ADDRESS Connect to ADDRESS
+ -l, --listen ADDRESS Listen on ADDRESS
+ -K, --key FILE Use FILE as private key
+ -C, --cert FILE Use FILE as public key
+ -A, --cacert FILE Use FILE as public CA cert file
+ -H, --hostname HOSTNAME Use HOSTNAME to validate the CN of the peer
+ rather than hostname extracted from -C option
+ -s, --server Run the listen port encrypted rather than the
+ connect port
+ -i, --insecure Do not validate certificates
+ -n, --nofork Do not fork off (aids debugging); specify twice
+ to stop forking on accept as well
+ -d, --debug Turn on debugging
+ -h, --help Show this usage message
+```
+
+License
+=======
+
+MIT
diff --git a/doc/examples/tlsproxy/buffer.c b/doc/examples/tlsproxy/buffer.c
new file mode 100644
index 0000000..05c8212
--- /dev/null
+++ b/doc/examples/tlsproxy/buffer.c
@@ -0,0 +1,228 @@
+/*
+
+The MIT License (MIT)
+
+Copyright (c) 2016 Wrymouth Innovation Ltd
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+
+#include "config.h"
+#include <sys/types.h>
+
+#include "buffer.h"
+
+struct buffer
+{
+ char *buf;
+ ssize_t size;
+ ssize_t hwm;
+ ssize_t ridx;
+ ssize_t widx;
+ int empty;
+};
+
+/* the buffer is organised internally as follows:
+ *
+ * * There are b->size bytes in the buffer.
+ *
+ * * Bytes are at offsets 0 to b->size-1
+ *
+ * * b->ridx points to the first readable byte
+ *
+ * * b->widx points to the first empty space
+ *
+ * * b->ridx < b->widx indicates a non-wrapped buffer:
+ *
+ * 0 ridx widx size
+ * | | | |
+ * V V V V
+ * ........XXXXXXXXX................
+ *
+ * * b->ridx > b->widx indicates a wrapped buffer:
+ *
+ * 0 widx ridx size
+ * | | | |
+ * V V V V
+ * XXXXXXXX.........XXXXXXXXXXXXXXXX
+ *
+ * * b->ridx == b->widx indicates a FULL buffer:
+ *
+ * * b->ridx == b->widx indicates a wrapped buffer:
+ *
+ * 0 widx == ridx size
+ * | | |
+ * V V V
+ * XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+ *
+ * An empty buffer is indicated by empty=1
+ *
+ */
+
+buffer_t *
+bufNew (ssize_t size, ssize_t hwm)
+{
+ buffer_t *b = calloc (1, sizeof (buffer_t));
+ if (!b) return NULL;
+
+ b->buf = calloc (1, size);
+ b->size = size;
+ b->hwm = hwm;
+ b->empty = 1;
+ return b;
+}
+
+
+void
+bufFree (buffer_t * b)
+{
+ free (b->buf);
+ free (b);
+}
+
+/* get a maximal span to read. Returns 0 if buffer
+ * is empty
+ */
+ssize_t
+bufGetReadSpan (buffer_t * b, void **addr)
+{
+ if (b->empty)
+ {
+ *addr = NULL;
+ return 0;
+ }
+ *addr = &(b->buf[b->ridx]);
+ ssize_t len = b->widx - b->ridx;
+ if (len <= 0)
+ len = b->size - b->ridx;
+ return len;
+}
+
+/* get a maximal span to write. Returns 0 id buffer is full
+ */
+ssize_t
+bufGetWriteSpan (buffer_t * b, void **addr)
+{
+ if (b->empty)
+ {
+ *addr = b->buf;
+ b->ridx = 0;
+ b->widx = 0;
+ return b->size;
+ }
+ if (b->ridx == b->widx)
+ {
+ *addr = NULL;
+ return 0;
+ }
+ *addr = &(b->buf[b->widx]);
+ ssize_t len = b->ridx - b->widx;
+ if (len <= 0)
+ len = b->size - b->widx;
+ return len;
+}
+
+/* mark size bytes as read */
+void
+bufDoneRead (buffer_t * b, ssize_t size)
+{
+ while (!b->empty && (size > 0))
+ {
+ /* empty can't occur here, so equal pointers means full */
+ ssize_t len = b->widx - b->ridx;
+ if (len <= 0)
+ len = b->size - b->ridx;
+
+ /* len is the number of bytes in one read span */
+ if (len > size)
+ len = size;
+
+ b->ridx += len;
+ if (b->ridx >= b->size)
+ b->ridx = 0;
+
+ if (b->ridx == b->widx)
+ {
+ b->ridx = 0;
+ b->widx = 0;
+ b->empty = 1;
+ }
+
+ size -= len;
+ }
+}
+
+/* mark size bytes as written */
+void
+bufDoneWrite (buffer_t * b, ssize_t size)
+{
+ while ((b->empty || (b->ridx != b->widx)) && (size > 0))
+ {
+ /* full can't occur here, so equal pointers means empty */
+ ssize_t len = b->ridx - b->widx;
+ if (len <= 0)
+ len = b->size - b->widx;
+
+ /* len is the number of bytes in one write span */
+ if (len > size)
+ len = size;
+
+ b->widx += len;
+ if (b->widx >= b->size)
+ b->widx = 0;
+
+ /* it can't be empty as we've written at least one byte */
+ b->empty = 0;
+
+ size -= len;
+ }
+}
+
+int
+bufIsEmpty (buffer_t * b)
+{
+ return b->empty;
+}
+
+int
+bufIsFull (buffer_t * b)
+{
+ return !b->empty && (b->ridx == b->widx);
+}
+
+int
+bufIsOverHWM (buffer_t * b)
+{
+ return bufGetCount (b) > b->hwm;
+}
+
+ssize_t
+bufGetFree (buffer_t * b)
+{
+ return b->size - bufGetCount (b);
+}
+
+ssize_t
+bufGetCount (buffer_t * b)
+{
+ if (b->empty)
+ return 0;
+ return b->widx - b->ridx + ((b->ridx < b->widx) ? 0 : b->size);
+}
diff --git a/doc/examples/tlsproxy/buffer.h b/doc/examples/tlsproxy/buffer.h
new file mode 100644
index 0000000..c92b9a6
--- /dev/null
+++ b/doc/examples/tlsproxy/buffer.h
@@ -0,0 +1,45 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Wrymouth Innovation Ltd
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#ifndef __TLSPROXY_BUFFERS_H
+#define __TLSPROXY_BUFFERS_H
+
+#include <stdlib.h>
+#include <sys/types.h>
+
+typedef struct buffer buffer_t;
+
+buffer_t *bufNew (ssize_t size, ssize_t hwm);
+void bufFree (buffer_t * b);
+ssize_t bufGetReadSpan (buffer_t * b, void **addr);
+ssize_t bufGetWriteSpan (buffer_t * b, void **addr);
+void bufDoneRead (buffer_t * b, ssize_t size);
+void bufDoneWrite (buffer_t * b, ssize_t size);
+int bufIsEmpty (buffer_t * b);
+int bufIsFull (buffer_t * b);
+int bufIsOverHWM (buffer_t * b);
+ssize_t bufGetFree (buffer_t * b);
+ssize_t bufGetCount (buffer_t * b);
+
+#endif
diff --git a/doc/examples/tlsproxy/crypto-gnutls.c b/doc/examples/tlsproxy/crypto-gnutls.c
new file mode 100644
index 0000000..5db51a3
--- /dev/null
+++ b/doc/examples/tlsproxy/crypto-gnutls.c
@@ -0,0 +1,585 @@
+/*
+
+The MIT License (MIT)
+
+Copyright (c) 2016 Wrymouth Innovation Ltd
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+
+#include "config.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <gnutls/gnutls.h>
+#include <gnutls/crypto.h>
+#include <gnutls/x509.h>
+#include <gnutls/abstract.h>
+
+#include "crypto-gnutls.h"
+#include "buffer.h"
+
+#define FALSE 0
+#define TRUE 1
+
+struct tlssession
+{
+ gnutls_certificate_credentials_t creds;
+ gnutls_session_t session;
+ char *hostname;
+ int (*quitfn) (void *opaque);
+ int (*erroutfn) (void *opaque, const char *format, va_list ap);
+ int debug;
+ void *opaque;
+};
+
+#define BUF_SIZE 65536
+#define BUF_HWM ((BUF_SIZE*3)/4)
+
+static int
+falsequit (void *opaque)
+{
+ return FALSE;
+}
+
+static int
+quit (tlssession_t * s)
+{
+ return s->quitfn (s->opaque);
+}
+
+#if defined __clang__ || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+# pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
+#endif
+
+static int stderrout (void *opaque, const char *format, va_list ap)
+{
+ return vfprintf (stderr, format, ap);
+}
+
+static int
+errout (tlssession_t * s, const char *format, ...)
+{
+ va_list ap;
+ int ret;
+ va_start (ap, format);
+ ret = s->erroutfn (s->opaque, format, ap);
+ va_end (ap);
+ return ret;
+}
+
+static int
+debugout (tlssession_t * s, const char *format, ...)
+{
+ va_list ap;
+ int ret = 0;
+ va_start (ap, format);
+ if (s->debug)
+ ret = s->erroutfn (s->opaque, format, ap);
+ va_end (ap);
+ return ret;
+}
+
+static int
+socksetnonblock (int fd, int nb)
+{
+ int sf = fcntl (fd, F_GETFL, 0);
+ if (sf == -1)
+ return -1;
+ return fcntl (fd, F_SETFL, nb ? (sf | O_NONBLOCK) : (sf & ~O_NONBLOCK));
+}
+
+/* From (public domain) example file in GNUTLS
+ *
+ * This function will try to verify the peer's certificate, and
+ * also check if the hostname matches, and the activation, expiration dates.
+ */
+static int
+verify_certificate_callback (gnutls_session_t session)
+{
+ unsigned int status;
+ int ret;
+ tlssession_t *s;
+
+ /* read session pointer */
+ s = (tlssession_t *) gnutls_session_get_ptr (session);
+
+ if (gnutls_certificate_type_get (session) != GNUTLS_CRT_X509)
+ return GNUTLS_E_CERTIFICATE_ERROR;
+
+ /* This verification function uses the trusted CAs in the credentials
+ * structure. So you must have installed one or more CA certificates.
+ */
+ if (s->hostname && *s->hostname)
+ ret = gnutls_certificate_verify_peers3 (session, s->hostname, &status);
+ else
+ ret = gnutls_certificate_verify_peers2 (session, &status);
+
+ if (ret < 0)
+ {
+ debugout (s, "Could not verify peer certificate due to an error\n");
+ return GNUTLS_E_CERTIFICATE_ERROR;
+ }
+
+ if (status)
+ {
+ gnutls_datum_t txt;
+ ret = gnutls_certificate_verification_status_print(status, GNUTLS_CRT_X509,
+ &txt, 0);
+ if (ret >= 0)
+ {
+ debugout (s, "verification error: %s\n", txt.data);
+ gnutls_free(txt.data);
+ }
+
+ return GNUTLS_E_CERTIFICATE_ERROR;
+ }
+
+ debugout (s, "Peer passed certificate verification\n");
+
+ /* notify gnutls to continue handshake normally */
+ return 0;
+}
+
+tlssession_t *
+tlssession_new (int isserver,
+ char *keyfile, char *certfile, char *cacertfile,
+ char *hostname, int insecure, int debug,
+ int (*quitfn) (void *opaque),
+ int (*erroutfn) (void *opaque, const char *format,
+ va_list ap), void *opaque)
+{
+ int ret;
+ tlssession_t *s = calloc (1, sizeof (tlssession_t));
+ if (!s)
+ return NULL;
+
+ if (quitfn)
+ s->quitfn = quitfn;
+ else
+ s->quitfn = falsequit;
+
+ if (erroutfn)
+ s->erroutfn = erroutfn;
+ else
+ s->erroutfn = stderrout;
+
+ if (hostname)
+ s->hostname = strdup (hostname);
+
+ s->debug = debug;
+
+ if (gnutls_certificate_allocate_credentials (&s->creds) < 0)
+ {
+ errout (s, "Certificate allocation memory error\n");
+ goto error;
+ }
+
+ if (cacertfile != NULL)
+ {
+ ret =
+ gnutls_certificate_set_x509_trust_file (s->creds, cacertfile,
+ GNUTLS_X509_FMT_PEM);
+ if (ret < 0)
+ {
+ errout (s, "Error setting the x509 trust file: %s\n",
+ gnutls_strerror (ret));
+ goto error;
+ }
+
+ if (!insecure)
+ {
+ gnutls_certificate_set_verify_function (s->creds,
+ verify_certificate_callback);
+ gnutls_certificate_set_verify_flags (s->creds,
+ GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT);
+ }
+ }
+
+ if (keyfile && !certfile)
+ certfile = keyfile;
+
+ if (certfile != NULL && keyfile != NULL)
+ {
+ ret =
+ gnutls_certificate_set_x509_key_file (s->creds, certfile, keyfile,
+ GNUTLS_X509_FMT_PEM);
+
+ if (ret < 0)
+ {
+ errout (s,
+ "Error loading certificate or key file (%s, %s): %s\n",
+ certfile, keyfile, gnutls_strerror (ret));
+ goto error;
+ }
+ }
+
+ if (isserver)
+ ret = gnutls_init (&s->session, GNUTLS_SERVER);
+ else
+ ret = gnutls_init (&s->session, GNUTLS_CLIENT);
+
+ if (ret < 0)
+ {
+ errout (s, "Cannot initialize GNUTLS session: %s\n",
+ gnutls_strerror (ret));
+ goto error;
+ }
+
+ gnutls_session_set_ptr (s->session, (void *) s);
+
+ if (!isserver && s->hostname && *s->hostname)
+ {
+ ret = gnutls_server_name_set (s->session, GNUTLS_NAME_DNS, s->hostname,
+ strlen (s->hostname));
+ if (ret < 0)
+ {
+ errout (s, "Cannot set server name: %s\n",
+ gnutls_strerror (ret));
+ goto error;
+ }
+ }
+
+ ret = gnutls_set_default_priority (s->session);
+ if (ret < 0)
+ {
+ errout (s, "Cannot set default GNUTLS session priority: %s\n",
+ gnutls_strerror (ret));
+ goto error;
+ }
+
+ ret = gnutls_credentials_set (s->session, GNUTLS_CRD_CERTIFICATE, s->creds);
+ if (ret < 0)
+ {
+ errout (s, "Cannot set session GNUTL credentials: %s\n",
+ gnutls_strerror (ret));
+ goto error;
+ }
+
+ if (isserver)
+ {
+ /* requests but does not check a client certificate */
+ gnutls_certificate_server_set_request (s->session, GNUTLS_CERT_REQUEST);
+ }
+
+
+ return s;
+
+error:
+ if (s->session)
+ gnutls_deinit (s->session);
+ free (s);
+ return NULL;
+}
+
+void
+tlssession_close (tlssession_t * s)
+{
+ if (s->session)
+ gnutls_deinit (s->session);
+ free (s->hostname);
+ free (s);
+}
+
+int
+tlssession_init (void)
+{
+ return gnutls_global_init ();
+}
+
+
+int
+tlssession_mainloop (int cryptfd, int plainfd, tlssession_t * s)
+{
+ fd_set readfds;
+ fd_set writefds;
+ int maxfd;
+ int tls_wr_interrupted = 0;
+ int plainEOF = FALSE;
+ int cryptEOF = FALSE;
+ ssize_t ret;
+
+ buffer_t *plainToCrypt = bufNew (BUF_SIZE, BUF_HWM);
+ buffer_t *cryptToPlain = bufNew (BUF_SIZE, BUF_HWM);
+
+ if (socksetnonblock (cryptfd, 0) < 0)
+ {
+ errout (s, "Could not turn on blocking: %m");
+ goto error;
+ }
+
+ /* set it up to work with our FD */
+ gnutls_transport_set_ptr (s->session,
+ (gnutls_transport_ptr_t) (intptr_t) cryptfd);
+
+
+ /* Now do the handshake */
+ ret = gnutls_handshake (s->session);
+ if (ret < 0)
+ {
+ errout (s, "TLS handshake failed: %s\n", gnutls_strerror (ret));
+ goto error;
+ }
+
+ if (socksetnonblock (cryptfd, 1) < 0)
+ {
+ errout (s, "Could not turn on non-blocking on crypt FD: %m");
+ goto error;
+ }
+
+ if (socksetnonblock (plainfd, 1) < 0)
+ {
+ errout (s, "Could not turn on non-blocking on plain FD: %m");
+ goto error;
+ }
+
+ maxfd = (plainfd > cryptfd) ? plainfd + 1 : cryptfd + 1;
+
+ while ((!plainEOF || !cryptEOF) && !quit (s))
+ {
+ struct timeval timeout;
+ int result;
+ int selecterrno;
+ int wait = TRUE;
+
+ FD_ZERO (&readfds);
+ FD_ZERO (&writefds);
+
+ size_t buffered = gnutls_record_check_pending (s->session);
+ if (buffered)
+ wait = FALSE; /* do not wait for select to return if we have buffered data */
+
+ if (plainEOF)
+ {
+ /* plain text end has closed, but me may still have
+ * data yet to write to the crypt end */
+ if (bufIsEmpty (plainToCrypt) && !tls_wr_interrupted)
+ {
+ cryptEOF = TRUE;
+ break;
+ }
+ }
+ else
+ {
+ if (!bufIsEmpty (cryptToPlain))
+ FD_SET (plainfd, &writefds);
+ if (!bufIsOverHWM (plainToCrypt))
+ FD_SET (plainfd, &readfds);
+ }
+
+ if (cryptEOF)
+ {
+ /* crypt end has closed, but me way still have data to
+ * write from the crypt buffer */
+ if (bufIsEmpty (cryptToPlain) && !buffered)
+ {
+ plainEOF = TRUE;
+ break;
+ }
+ }
+ else
+ {
+ if (!bufIsEmpty (plainToCrypt) || tls_wr_interrupted)
+ FD_SET (cryptfd, &writefds);
+ if (!bufIsOverHWM (cryptToPlain))
+ FD_SET (cryptfd, &readfds);
+ }
+
+ /* Repeat select whilst EINTR happens */
+ do
+ {
+ timeout.tv_sec = wait ? 1 : 0;
+ timeout.tv_usec = 0;
+ result = select (maxfd, &readfds, &writefds, NULL, &timeout);
+
+ selecterrno = errno;
+ }
+ while ((result == -1) && (selecterrno == EINTR) && !quit (s));
+ if (quit (s))
+ break;
+
+ if (FD_ISSET (plainfd, &readfds))
+ {
+ /* we can read at least one byte */
+ void *addr = NULL;
+ /* get a span of characters to write to the
+ * buffer. As the empty portion may wrap the end of the
+ * circular buffer this might not be all we could read.
+ */
+ ssize_t len = bufGetWriteSpan (plainToCrypt, &addr);
+ if (len > 0)
+ {
+ do
+ {
+ ret = read (plainfd, addr, (size_t) len);
+ }
+ while ((ret < 0) && (errno == EINTR) && !quit (s));
+ if (quit (s))
+ break;
+ if (ret < 0)
+ {
+ errout (s, "Error on read from plain socket: %m\n");
+ goto error;
+ }
+ if (ret == 0)
+ {
+ plainEOF = TRUE;
+ }
+ else
+ {
+ bufDoneWrite (plainToCrypt, ret); /* mark ret bytes as written to the buffer */
+ }
+ }
+ }
+
+ if (FD_ISSET (plainfd, &writefds))
+ {
+ /* we can write at least one byte */
+ void *addr = NULL;
+ /* get a span of characters to read from the buffer
+ * as the full portion may wrap the end of the circular buffer
+ * this might not be all we have to write.
+ */
+ ssize_t len = bufGetReadSpan (cryptToPlain, &addr);
+ if (len > 0)
+ {
+ do
+ {
+ ret = write (plainfd, addr, (size_t) len);
+ }
+ while ((ret < 0) && (errno == EINTR) && !quit (s));
+ if (quit (s))
+ break;
+ if (ret < 0)
+ {
+ errout (s, "Error on write to plain socket: %m\n");
+ goto error;
+ }
+ bufDoneRead (cryptToPlain, ret); /* mark ret bytes as read from the buffer */
+ }
+ }
+
+ if (FD_ISSET (cryptfd, &readfds) || buffered)
+ {
+ /* we can read at least one byte */
+ void *addr = NULL;
+ /* get a span of characters to write to the
+ * buffer. As the empty portion may wrap the end of the
+ * circular buffer this might not be all we could read.
+ */
+ ssize_t len = bufGetWriteSpan (cryptToPlain, &addr);
+ if (len > 0)
+ {
+ do
+ {
+ ret = gnutls_record_recv (s->session, addr, (size_t) len);
+ }
+ while (ret == GNUTLS_E_INTERRUPTED && !quit (s));
+ /* do not loop on GNUTLS_E_AGAIN - this means we'd block so we'd loop for
+ * ever
+ */
+ if (quit (s))
+ break;
+ if (ret < 0 && ret != GNUTLS_E_AGAIN)
+ {
+ errout (s, "Error on read from crypt socket: %s\n",
+ gnutls_strerror (ret));
+ goto error;
+ }
+ if (ret == 0)
+ {
+ cryptEOF = TRUE;
+ }
+ else
+ {
+ bufDoneWrite (cryptToPlain, ret); /* mark ret bytes as written to the buffer */
+ }
+ }
+ }
+
+ if (FD_ISSET (cryptfd, &writefds))
+ {
+ /* we can write at least one byte */
+ void *addr = NULL;
+ /* get a span of characters to read from the buffer
+ * as the full portion may wrap the end of the circular buffer
+ * this might not be all we have to write.
+ */
+ ssize_t len = bufGetReadSpan (plainToCrypt, &addr);
+ if (len > 0)
+ {
+ do
+ {
+ if (tls_wr_interrupted)
+ {
+ ret = gnutls_record_send (s->session, NULL, 0);
+ }
+ else
+ {
+ ret = gnutls_record_send (s->session, addr, len);
+ }
+ }
+ while (ret == GNUTLS_E_INTERRUPTED && !quit (s));
+ if (quit (s))
+ break;
+ if (ret == GNUTLS_E_AGAIN)
+ {
+ /* we need to call this again with NULL parameters
+ * as it blocked
+ */
+ tls_wr_interrupted = TRUE;
+ }
+ else if (ret < 0)
+ {
+ errout (s, "Error on write to crypto socket: %s\n",
+ gnutls_strerror (ret));
+ goto error;
+ }
+ else
+ {
+ bufDoneRead (plainToCrypt, ret); /* mark ret bytes as read from the buffer */
+ }
+ }
+ }
+ }
+
+ ret = 0;
+ goto freereturn;
+
+error:
+ ret = -1;
+
+freereturn:
+ gnutls_bye (s->session, GNUTLS_SHUT_RDWR);
+ shutdown (plainfd, SHUT_RDWR);
+ bufFree (plainToCrypt);
+ bufFree (cryptToPlain);
+ return ret;
+}
diff --git a/doc/examples/tlsproxy/crypto-gnutls.h b/doc/examples/tlsproxy/crypto-gnutls.h
new file mode 100644
index 0000000..2b6c402
--- /dev/null
+++ b/doc/examples/tlsproxy/crypto-gnutls.h
@@ -0,0 +1,43 @@
+/*
+
+The MIT License (MIT)
+
+Copyright (c) 2016 Wrymouth Innovation Ltd
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+
+#ifndef __TLSPROXY_CRYPTO_GNUTLS_H
+#define __TLSPROXY_CRYPTO_GNUTLS_H
+
+int tlssession_init (void);
+
+typedef struct tlssession tlssession_t;
+tlssession_t *tlssession_new (int isserver,
+ char *keyfile, char *certfile, char *cacertfile,
+ char *hostname, int insecure, int debug,
+ int (*quitfn) (void *opaque),
+ int (*erroutfn) (void *opaque,
+ const char *format,
+ va_list ap), void *opaque);
+void tlssession_close (tlssession_t * s);
+int tlssession_mainloop (int cryptfd, int plainfd, tlssession_t * session);
+
+#endif
diff --git a/doc/examples/tlsproxy/tlsproxy.c b/doc/examples/tlsproxy/tlsproxy.c
new file mode 100644
index 0000000..8e781f7
--- /dev/null
+++ b/doc/examples/tlsproxy/tlsproxy.c
@@ -0,0 +1,464 @@
+/*
+
+The MIT License (MIT)
+
+Copyright (c) 2016 Wrymouth Innovation Ltd
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+
+#include "config.h"
+
+#include <errno.h>
+#include <getopt.h>
+#include <netdb.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include "crypto-gnutls.h"
+
+static char *connectaddr = NULL;
+static char *listenaddr = NULL;
+static char *keyfile = NULL;
+static char *certfile = NULL;
+static char *cacertfile = NULL;
+static char *hostname = NULL;
+static int debug = 0;
+static int insecure = 0;
+static int nofork = 0;
+static int server = 0;
+
+static const char *defaultport = "12345";
+
+static volatile sig_atomic_t rxsigquit = 0;
+
+static int
+bindtoaddress (char *addrport)
+{
+ struct addrinfo hints;
+ struct addrinfo *result, *rp;
+ int fd, s;
+ char addr[128];
+
+ snprintf(addr, sizeof(addr), "%s", addrport);
+
+ memset (&hints, 0, sizeof (struct addrinfo));
+ hints.ai_flags = AI_PASSIVE; /* For wildcard IP address */
+ hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */
+ hints.ai_socktype = SOCK_STREAM; /* Stream socket */
+ hints.ai_protocol = 0; /* any protocol */
+
+ char *colon = strrchr (addr, ':');
+ const char *port = defaultport;
+ if (colon)
+ {
+ *colon = 0;
+ port = colon + 1;
+ }
+
+ s = getaddrinfo (addr, port, &hints, &result);
+ if (s != 0)
+ {
+ fprintf (stderr, "Error in address %s: %s\n", addr, gai_strerror (s));
+ return -1;
+ }
+
+ /* attempt to bind to each address */
+
+ for (rp = result; rp != NULL; rp = rp->ai_next)
+ {
+ fd = socket (rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+
+ if (fd >= 0)
+ {
+ int one = 1;
+ if (setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof (one)) <
+ 0)
+ {
+ close (fd);
+ continue;
+ }
+ if (bind (fd, rp->ai_addr, rp->ai_addrlen) == 0)
+ break;
+ close (fd);
+ }
+ }
+
+ if (!rp)
+ {
+ fprintf (stderr, "Error binding to %s:%s: %m\n", addr, port);
+ freeaddrinfo (result);
+ return -1;
+ }
+
+ freeaddrinfo (result); /* No longer needed */
+
+ if (listen (fd, 5) < 0)
+ {
+ close (fd);
+ return -1;
+ }
+
+ return fd;
+}
+
+static int
+connecttoaddress (char *addrport)
+{
+ struct addrinfo hints;
+ struct addrinfo *result, *rp;
+ int fd, s;
+ char addr[128];
+
+ snprintf(addr, sizeof(addr), "%s", addrport);
+
+ memset (&hints, 0, sizeof (struct addrinfo));
+ hints.ai_flags = AI_PASSIVE; /* For wildcard IP address */
+ hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */
+ hints.ai_socktype = SOCK_STREAM; /* Stream socket */
+ hints.ai_protocol = 0; /* any protocol */
+
+ char *colon = strrchr (addr, ':');
+ const char *port = defaultport;
+ if (colon)
+ {
+ *colon = 0;
+ port = colon + 1;
+ }
+
+ if (!hostname && !server)
+ hostname = strdup (addr);
+
+ s = getaddrinfo (addr, port, &hints, &result);
+ if (s != 0)
+ {
+ fprintf (stderr, "Error in address %s: %s\n", addr, gai_strerror (s));
+ return -1;
+ }
+
+ /* attempt to connect to each address */
+ for (rp = result; rp != NULL; rp = rp->ai_next)
+ {
+ fd = socket (rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+ if (fd >= 0)
+ {
+ if (connect (fd, rp->ai_addr, rp->ai_addrlen) == 0)
+ break;
+ close (fd);
+ }
+ }
+
+ if (!rp)
+ {
+ fprintf (stderr, "Error connecting to %s:%s: %m\n", addr, port);
+ freeaddrinfo (result);
+ return -1;
+ }
+
+ freeaddrinfo (result); /* No longer needed */
+
+ return fd;
+}
+
+static int
+quitfn (void *opaque)
+{
+ return rxsigquit;
+}
+
+static int
+runproxy (int acceptfd)
+{
+ int connectfd;
+ if ((connectfd = connecttoaddress (connectaddr)) < 0)
+ {
+ fprintf (stderr, "Could not connect\n");
+ close (acceptfd);
+ return -1;
+ }
+
+ tlssession_t *session =
+ tlssession_new (server, keyfile, certfile, cacertfile, hostname, insecure,
+ debug, quitfn, NULL, NULL);
+ if (!session)
+ {
+ fprintf (stderr, "Could create TLS session\n");
+ close (connectfd);
+ close (acceptfd);
+ return -1;
+ }
+
+ int ret;
+ if (server)
+ ret = tlssession_mainloop (acceptfd, connectfd, session);
+ else
+ ret = tlssession_mainloop (connectfd, acceptfd, session);
+
+ tlssession_close (session);
+ close (connectfd);
+ close (acceptfd);
+
+ if (ret < 0)
+ {
+ fprintf (stderr, "TLS proxy exited with an error\n");
+ return -1;
+ }
+ return 0;
+}
+
+static int
+runlistener (void)
+{
+ int listenfd;
+ if ((listenfd = bindtoaddress (listenaddr)) < 0)
+ {
+ fprintf (stderr, "Could not bind listener\n");
+ return -1;
+ }
+
+ /*
+ if (!nofork)
+ daemon (FALSE, FALSE);
+ */
+
+ int fd;
+ while (!rxsigquit)
+ {
+ do
+ {
+ if ((fd = accept (listenfd, NULL, NULL)) < 0)
+ {
+ if (errno != EINTR)
+ {
+ fprintf (stderr, "Accept failed\n");
+ return -1;
+ }
+ }
+ }
+ while (fd < 0 && !rxsigquit);
+ if (rxsigquit)
+ break;
+ if (nofork < 2)
+ {
+ int ret = runproxy (fd);
+ if (ret < 0)
+ return -1;
+ }
+ else
+ {
+ int cpid = fork ();
+ if (cpid == 0)
+ {
+ /* we're the child */
+ runproxy (fd);
+ exit (0);
+ }
+ else
+ close (fd);
+ }
+ }
+ return 0;
+}
+
+static void
+usage (void)
+{
+ fprintf (stderr, "tlsproxy\n\n\
+Usage:\n\
+ tlsproxy [OPTIONS]\n\
+\n\
+A TLS client or server proxy\n\
+\n\
+Options:\n\
+ -c, --connect ADDRESS Connect to ADDRESS\n\
+ -l, --listen ADDRESS Listen on ADDRESS\n\
+ -K, --key FILE Use FILE as private key\n\
+ -C, --cert FILE Use FILE as public key\n\
+ -A, --cacert FILE Use FILE as public CA cert file\n\
+ -H, --hostname HOSTNAME Use HOSTNAME to validate the CN of the peer\n\
+ rather than hostname extracted from -C option\n\
+ -s, --server Run the listen port encrypted rather than the\n\
+ connect port\n\
+ -i, --insecure Do not validate certificates\n\
+ -n, --nofork Do not fork off (aids debugging); specify twice\n\
+ to stop forking on accept as well\n\
+ -d, --debug Turn on debugging\n\
+ -h, --help Show this usage message\n\
+\n\
+\n");
+}
+
+static void
+processoptions (int argc, char **argv)
+{
+ while (1)
+ {
+ static const struct option longopts[] = {
+ {"connect", required_argument, 0, 'c'},
+ {"listen", required_argument, 0, 'l'},
+ {"key", required_argument, 0, 'K'},
+ {"cert", required_argument, 0, 'C'},
+ {"cacert", required_argument, 0, 'A'},
+ {"hostname", required_argument, 0, 'H'},
+ {"server", no_argument, 0, 's'},
+ {"insecure", no_argument, 0, 'i'},
+ {"nofork", no_argument, 0, 'n'},
+ {"debug", no_argument, 0, 'd'},
+ {"help", no_argument, 0, 'h'},
+ {0, 0, 0, 0}
+ };
+
+ int optidx = 0;
+
+ int c =
+ getopt_long (argc, argv, "c:l:K:C:A:H:sindh", longopts, &optidx);
+ if (c == -1)
+ break;
+
+ switch (c)
+ {
+ case 0: /* set a flag, nothing else to do */
+ break;
+
+ case 'c':
+ free (connectaddr);
+ connectaddr = strdup (optarg);
+ break;
+
+ case 'l':
+ free (listenaddr);
+ listenaddr = strdup (optarg);
+ break;
+
+ case 'K':
+ free (keyfile);
+ keyfile = strdup (optarg);
+ break;
+
+ case 'C':
+ free (certfile);
+ certfile = strdup (optarg);
+ break;
+
+ case 'A':
+ free (cacertfile);
+ cacertfile = strdup (optarg);
+ break;
+
+ case 'H':
+ free (hostname);
+ hostname = strdup (optarg);
+ break;
+
+ case 's':
+ server = 1;
+ break;
+
+ case 'i':
+ insecure = 1;
+ break;
+
+ case 'n':
+ nofork++;
+ break;
+
+ case 'd':
+ debug++;
+ break;
+
+ case 'h':
+ usage ();
+ exit (0);
+ break;
+
+ default:
+ usage ();
+ exit (1);
+ }
+ }
+
+ if (optind != argc || !connectaddr || !listenaddr)
+ {
+ usage ();
+ exit (1);
+ }
+
+ if (!certfile && keyfile)
+ certfile = strdup (keyfile);
+}
+
+static void
+handlesignal (int sig)
+{
+ switch (sig)
+ {
+ case SIGINT:
+ case SIGTERM:
+ rxsigquit++;
+ break;
+ default:
+ break;
+ }
+}
+
+static void
+setsignalmasks (void)
+{
+ struct sigaction sa;
+ /* Set up the structure to specify the new action. */
+ memset (&sa, 0, sizeof (struct sigaction));
+ sa.sa_handler = handlesignal;
+ sigemptyset (&sa.sa_mask);
+ sa.sa_flags = 0;
+ sigaction (SIGINT, &sa, NULL);
+ sigaction (SIGTERM, &sa, NULL);
+
+ memset (&sa, 0, sizeof (struct sigaction));
+ sa.sa_handler = SIG_IGN;
+ sa.sa_flags = SA_RESTART;
+ sigaction (SIGPIPE, &sa, NULL);
+}
+
+int
+main (int argc, char **argv)
+{
+ processoptions (argc, argv);
+
+ setsignalmasks ();
+
+ if (tlssession_init ())
+ exit (1);
+
+ runlistener ();
+
+ free (connectaddr);
+ free (listenaddr);
+ free (keyfile);
+ free (certfile);
+ free (cacertfile);
+ free (hostname);
+
+ exit (0);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-29 17:14:43 +0000