--- /dev/null
+From e25d93dec6d2907430f3680ad5fbdfedc1ee94d8 Mon Sep 17 00:00:00 2001
+From: Sachin Agrawal <sachin.agrawal@intel.com>
+Date: Sun, 15 Feb 2015 22:16:43 -0800
+Subject: [PATCH 1/1] Bug Fix in earlier rehandhsake implementation
+
+Identified a corner case in earlier rehandshake implementation where if
+no data transfer takes place between client and Server before re-handshake
+is issued, re-handshake process was failing. DTLS state machine does not
+update it's state at Server until the first data packet was received from
+client. Updated logic to detect for 're-handshake' situation when epoch
+mis-match happens. Also updated dtls-client test app to conveniently test
+the feature. Use 'client:rehandshake' command for testing.
+
+Change-Id: Idfaad7d477508603c35ad7948ca7c8f05e3228d0
+Signed-off-by: Sachin Agrawal <sachin.agrawal@intel.com>
+---
+ extlibs/tinydtls/dtls.c | 44 ++++++++++++++++++----------------
+ extlibs/tinydtls/tests/dtls-client.c | 27 +++++++++++++++++++++
+ 2 files changed, 50 insertions(+), 21 deletions(-)
+
+diff --git a/extlibs/tinydtls/dtls.c b/extlibs/tinydtls/dtls.c
+index a87d7f1..a923386 100644
+--- a/extlibs/tinydtls/dtls.c
++++ b/extlibs/tinydtls/dtls.c
+@@ -1562,6 +1562,7 @@ static void dtls_destroy_peer(dtls_context_t *ctx, dtls_peer_t *peer, int unlink
+ * \param ctx The DTLS context.
+ * \param peer The remote party we are talking to, if any.
+ * \param session Transport address of the remote peer.
++ * \param state Current state of the connection.
+ * \param msg The received datagram.
+ * \param msglen Length of \p msg.
+ * \return \c 1 if msg is a Client Hello with a valid cookie, \c 0 or
+@@ -3644,7 +3645,6 @@ dtls_handle_message(dtls_context_t *ctx,
+ int data_length; /* length of decrypted payload
+ (without MAC and padding) */
+ int err;
+- int bypass_epoch_check = 0;
+
+ /* check if we have DTLS state for addr/port/ifindex */
+ peer = dtls_get_peer(ctx, session);
+@@ -3668,24 +3668,21 @@ dtls_handle_message(dtls_context_t *ctx,
+ data = msg + DTLS_RH_LENGTH;
+ data_length = rlen - DTLS_RH_LENGTH;
+ state = DTLS_STATE_WAIT_CLIENTHELLO;
+- role = DTLS_SERVER;
+- /* Bypass epoch check as the epoch for incoming msg is 0
+- and expected epoch MAY be different */
+- bypass_epoch_check = 1;
++ role = DTLS_SERVER;
+ } else {
+- int err = dtls_alert_fatal_create(DTLS_ALERT_DECRYPT_ERROR);
+- dtls_info("decrypt_verify() failed\n");
+- if (peer->state < DTLS_STATE_CONNECTED) {
+- dtls_alert_send_from_err(ctx, peer, &peer->session, err);
+- peer->state = DTLS_STATE_CLOSED;
+- /* dtls_stop_retransmission(ctx, peer); */
+- dtls_destroy_peer(ctx, peer, 1);
+- }
+- return err;
+- }
+- } else {
+- role = peer->role;
+- state = peer->state;
++ int err = dtls_alert_fatal_create(DTLS_ALERT_DECRYPT_ERROR);
++ dtls_info("decrypt_verify() failed\n");
++ if (peer->state < DTLS_STATE_CONNECTED) {
++ dtls_alert_send_from_err(ctx, peer, &peer->session, err);
++ peer->state = DTLS_STATE_CLOSED;
++ /* dtls_stop_retransmission(ctx, peer); */
++ dtls_destroy_peer(ctx, peer, 1);
++ }
++ return err;
++ }
++ } else {
++ role = peer->role;
++ state = peer->state;
+ }
+ } else {
+ /* is_record() ensures that msg contains at least a record header */
+@@ -3739,7 +3736,7 @@ dtls_handle_message(dtls_context_t *ctx,
+ /* Handshake messages other than Finish must use the current
+ * epoch, Finish has epoch + 1. */
+
+- if (peer && !bypass_epoch_check) {
++ if (peer) {
+ uint16_t expected_epoch = dtls_security_params(peer)->epoch;
+ uint16_t msg_epoch =
+ dtls_uint16_to_int(DTLS_RECORD_HEADER(msg)->epoch);
+@@ -3754,9 +3751,14 @@ dtls_handle_message(dtls_context_t *ctx,
+ }
+
+ if (expected_epoch != msg_epoch) {
+- dtls_warn("Wrong epoch, expected %i, got: %i\n",
++ if (hs_attempt_with_existing_peer(msg, rlen, peer)) {
++ state = DTLS_STATE_WAIT_CLIENTHELLO;
++ role = DTLS_SERVER;
++ } else {
++ dtls_warn("Wrong epoch, expected %i, got: %i\n",
+ expected_epoch, msg_epoch);
+- break;
++ break;
++ }
+ }
+ }
+
+diff --git a/extlibs/tinydtls/tests/dtls-client.c b/extlibs/tinydtls/tests/dtls-client.c
+index 306a380..05cb98f 100644
+--- a/extlibs/tinydtls/tests/dtls-client.c
++++ b/extlibs/tinydtls/tests/dtls-client.c
+@@ -44,6 +44,7 @@ typedef struct {
+ static dtls_str output_file = { 0, NULL }; /* output file name */
+
+ static dtls_context_t *dtls_context = NULL;
++static dtls_context_t *orig_dtls_context = NULL;
+
+
+ static const unsigned char ecdsa_priv_key[] = {
+@@ -235,6 +236,7 @@ dtls_handle_read(struct dtls_context_t *ctx) {
+ static void dtls_handle_signal(int sig)
+ {
+ dtls_free_context(dtls_context);
++ dtls_free_context(orig_dtls_context);
+ signal(sig, SIG_DFL);
+ kill(getpid(), sig);
+ }
+@@ -324,6 +326,12 @@ static dtls_handler_t cb = {
+ #define DTLS_CLIENT_CMD_CLOSE "client:close"
+ #define DTLS_CLIENT_CMD_RENEGOTIATE "client:renegotiate"
+
++/* As per RFC 6347 section 4.2.8, DTLS Server should support requests
++ * from clients who have silently abandoned the existing association
++ * and initiated a new handshake request by sending a ClientHello.
++ * Below command tests this feature.
++ */
++#define DTLS_CLIENT_CMD_REHANDSHAKE "client:rehandshake"
+ int
+ main(int argc, char **argv) {
+ fd_set rfds, wfds;
+@@ -504,6 +512,24 @@ main(int argc, char **argv) {
+ printf("client: renegotiate connection\n");
+ dtls_renegotiate(dtls_context, &dst);
+ len = 0;
++ } else if (len >= strlen(DTLS_CLIENT_CMD_REHANDSHAKE) &&
++ !memcmp(buf, DTLS_CLIENT_CMD_REHANDSHAKE, strlen(DTLS_CLIENT_CMD_REHANDSHAKE))) {
++ printf("client: rehandshake connection\n");
++ if (orig_dtls_context == NULL) {
++ /* Cache the current context. We cannot free the current context as it will notify
++ * the Server to close the connection (which we do not want).
++ */
++ orig_dtls_context = dtls_context;
++ /* Now, Create a new context and attempt to initiate a handshake. */
++ dtls_context = dtls_new_context(&fd);
++ if (!dtls_context) {
++ dtls_emerg("cannot create context\n");
++ exit(-1);
++ }
++ dtls_set_handler(dtls_context, &cb);
++ dtls_connect(dtls_context, &dst);
++ }
++ len = 0;
+ } else {
+ try_send(dtls_context, &dst);
+ }
+@@ -511,6 +537,7 @@ main(int argc, char **argv) {
+ }
+
+ dtls_free_context(dtls_context);
++ dtls_free_context(orig_dtls_context);
+ exit(0);
+ }
+
+--
+1.7.9.5
+
* \param ctx The DTLS context.
* \param peer The remote party we are talking to, if any.
* \param session Transport address of the remote peer.
+ * \param state Current state of the connection.
* \param msg The received datagram.
* \param msglen Length of \p msg.
* \return \c 1 if msg is a Client Hello with a valid cookie, \c 0 or
int data_length; /* length of decrypted payload
(without MAC and padding) */
int err;
- int bypass_epoch_check = 0;
/* check if we have DTLS state for addr/port/ifindex */
peer = dtls_get_peer(ctx, session);
data = msg + DTLS_RH_LENGTH;
data_length = rlen - DTLS_RH_LENGTH;
state = DTLS_STATE_WAIT_CLIENTHELLO;
- role = DTLS_SERVER;
- /* Bypass epoch check as the epoch for incoming msg is 0
- and expected epoch MAY be different */
- bypass_epoch_check = 1;
+ role = DTLS_SERVER;
} else {
- int err = dtls_alert_fatal_create(DTLS_ALERT_DECRYPT_ERROR);
- dtls_info("decrypt_verify() failed\n");
- if (peer->state < DTLS_STATE_CONNECTED) {
- dtls_alert_send_from_err(ctx, peer, &peer->session, err);
- peer->state = DTLS_STATE_CLOSED;
- /* dtls_stop_retransmission(ctx, peer); */
- dtls_destroy_peer(ctx, peer, 1);
- }
- return err;
- }
- } else {
- role = peer->role;
- state = peer->state;
+ int err = dtls_alert_fatal_create(DTLS_ALERT_DECRYPT_ERROR);
+ dtls_info("decrypt_verify() failed\n");
+ if (peer->state < DTLS_STATE_CONNECTED) {
+ dtls_alert_send_from_err(ctx, peer, &peer->session, err);
+ peer->state = DTLS_STATE_CLOSED;
+ /* dtls_stop_retransmission(ctx, peer); */
+ dtls_destroy_peer(ctx, peer, 1);
+ }
+ return err;
+ }
+ } else {
+ role = peer->role;
+ state = peer->state;
}
} else {
/* is_record() ensures that msg contains at least a record header */
/* Handshake messages other than Finish must use the current
* epoch, Finish has epoch + 1. */
- if (peer && !bypass_epoch_check) {
+ if (peer) {
uint16_t expected_epoch = dtls_security_params(peer)->epoch;
uint16_t msg_epoch =
dtls_uint16_to_int(DTLS_RECORD_HEADER(msg)->epoch);
}
if (expected_epoch != msg_epoch) {
- dtls_warn("Wrong epoch, expected %i, got: %i\n",
+ if (hs_attempt_with_existing_peer(msg, rlen, peer)) {
+ state = DTLS_STATE_WAIT_CLIENTHELLO;
+ role = DTLS_SERVER;
+ } else {
+ dtls_warn("Wrong epoch, expected %i, got: %i\n",
expected_epoch, msg_epoch);
- break;
+ break;
+ }
}
}
static dtls_str output_file = { 0, NULL }; /* output file name */
static dtls_context_t *dtls_context = NULL;
+static dtls_context_t *orig_dtls_context = NULL;
static const unsigned char ecdsa_priv_key[] = {
static void dtls_handle_signal(int sig)
{
dtls_free_context(dtls_context);
+ dtls_free_context(orig_dtls_context);
signal(sig, SIG_DFL);
kill(getpid(), sig);
}
#define DTLS_CLIENT_CMD_CLOSE "client:close"
#define DTLS_CLIENT_CMD_RENEGOTIATE "client:renegotiate"
+/* As per RFC 6347 section 4.2.8, DTLS Server should support requests
+ * from clients who have silently abandoned the existing association
+ * and initiated a new handshake request by sending a ClientHello.
+ * Below command tests this feature.
+ */
+#define DTLS_CLIENT_CMD_REHANDSHAKE "client:rehandshake"
int
main(int argc, char **argv) {
fd_set rfds, wfds;
printf("client: renegotiate connection\n");
dtls_renegotiate(dtls_context, &dst);
len = 0;
+ } else if (len >= strlen(DTLS_CLIENT_CMD_REHANDSHAKE) &&
+ !memcmp(buf, DTLS_CLIENT_CMD_REHANDSHAKE, strlen(DTLS_CLIENT_CMD_REHANDSHAKE))) {
+ printf("client: rehandshake connection\n");
+ if (orig_dtls_context == NULL) {
+ /* Cache the current context. We cannot free the current context as it will notify
+ * the Server to close the connection (which we do not want).
+ */
+ orig_dtls_context = dtls_context;
+ /* Now, Create a new context and attempt to initiate a handshake. */
+ dtls_context = dtls_new_context(&fd);
+ if (!dtls_context) {
+ dtls_emerg("cannot create context\n");
+ exit(-1);
+ }
+ dtls_set_handler(dtls_context, &cb);
+ dtls_connect(dtls_context, &dst);
+ }
+ len = 0;
} else {
try_send(dtls_context, &dst);
}
}
dtls_free_context(dtls_context);
+ dtls_free_context(orig_dtls_context);
exit(0);
}
projects / platform / upstream / iotivity.git / commitdiff