Merge branch 'iotssl-165-dtls-hs-fragmentation-new' into datagram_packing
diff --git a/ChangeLog b/ChangeLog
index ef8abc8..9817c59 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,10 @@
= mbed TLS x.x.x branch released xxxx-xx-xx
Features
+ * Add support for fragmentation of outgoing DTLS handshake messages. This
+ is controlled by the maximum fragment length as set locally or negotiated
+ with the peer, as well as new per-connection MTU option, set using
+ mbedtls_ssl_set_mtu().
* Add support for fragmentation of outoing DTLS handshake messages.
* Add support for packing multiple records within a single datagram,
enabled by default.
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 85ab722..f72833e 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -958,10 +958,6 @@
unsigned int dhm_min_bitlen; /*!< min. bit length of the DHM prime */
#endif
-#if defined(MBEDTLS_SSL_PROTO_DTLS)
- uint16_t mtu; /*!< path mtu, used to fragment outoing messages */
-#endif
-
unsigned char max_major_ver; /*!< max. major version used */
unsigned char max_minor_ver; /*!< max. minor version used */
unsigned char min_major_ver; /*!< min. major version used */
@@ -1123,6 +1119,10 @@
unsigned char cur_out_ctr[8]; /*!< Outgoing record sequence number. */
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+ uint16_t mtu; /*!< path mtu, used to fragment outgoing messages */
+#endif
+
#if defined(MBEDTLS_ZLIB_SUPPORT)
unsigned char *compress_buf; /*!< zlib data buffer */
#endif
@@ -1385,6 +1385,46 @@
mbedtls_ssl_recv_t *f_recv,
mbedtls_ssl_recv_timeout_t *f_recv_timeout );
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+/**
+ * \brief Set the Maximum Tranport Unit (MTU).
+ * Special value: 0 means unset (no limit).
+ * This represents the maximum size of a datagram payload
+ * handled by the transport layer (usually UDP) as determined
+ * by the network link and stack. In practice, this controls
+ * the maximum size datagram the DTLS layer will pass to the
+ * \c f_send() callback set using \c mbedtls_ssl_set_bio().
+ *
+ * \note This can be called at any point during the connection, for
+ * example when a PMTU estimate becomes available from other
+ * sources, such as lower (or higher) protocol layers.
+ *
+ * \note This only controls the size of the packets we send.
+ * Client-side, you can request the server to use smaller
+ * records with \c mbedtls_ssl_conf_max_frag_len().
+ *
+ * \note If both a MTU and a maximum fragment length have been
+ * configured (or negotiated with the peer), the resulting
+ * lower limit (after translating the MTU setting to a limit
+ * on the record content length) is used.
+ *
+ * \note This can only be used to decrease the maximum size
+ * of datagrams sent. It cannot be used to increase the
+ * maximum size of records over the limit set by
+ * #MBEDTLS_SSL_OUT_CONTENT_LEN.
+ *
+ * \note Values lower than the current record layer expansion will
+ * result in an error when trying to send data.
+ *
+ * \note Using record compression together with a non-zero MTU value
+ * will result in an error when trying to send data.
+ *
+ * \param ssl SSL context
+ * \param mtu Value of the path MTU in bytes
+ */
+void mbedtls_ssl_set_mtu( mbedtls_ssl_context *ssl, uint16_t mtu );
+#endif /* MBEDTLS_SSL_PROTO_DTLS */
+
/**
* \brief Set the timeout period for mbedtls_ssl_read()
* (Default: no timeout.)
@@ -2466,35 +2506,6 @@
char cert_req_ca_list );
#endif /* MBEDTLS_SSL_SRV_C */
-#if defined(MBEDTLS_SSL_PROTO_DTLS)
-/**
- * \brief Set the Maximum Tranport Unit (MTU).
- * Special value: 0 means unset (no limit).
- * This represents the maximum size of a datagram payload
- * handled by the transport layer (usually UDP) as determined
- * by the network link and stack. In practice, this controls
- * the maximum size datagram the DTLS layer will pass to the
- * \c f_send() callback set using \c mbedtls_ssl_set_bio().
- *
- * \note This only controls the size of the packet we send.
- * Client-side, you can request the server to use smaller
- * records with \c mbedtls_conf_max_frag_len().
- *
- * \note If both a MTU and a maximum fragment length have been
- * configured (or negotiated with the peer), the lower limit
- * is used.
- *
- * \note Values larger than \c MBEDTLS_SSL_OUT_CONTENT_LEN have no
- * effect. This can only be used to decrease the maximum size
- * of datagrams sent. Values lower than record layer expansion
- * are ignored.
- *
- * \param conf SSL configuration
- * \param mtu Value of the path MTU in bytes
- */
-void mbedtls_ssl_conf_mtu( mbedtls_ssl_config *conf, uint16_t mtu );
-#endif /* MBEDTLS_SSL_PROTO_DTLS */
-
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
/**
* \brief Set the maximum fragment length to emit and/or negotiate
@@ -2515,7 +2526,7 @@
*
* \note For DTLS, it is also possible to set a limit for the total
* size of daragrams passed to the transport layer, including
- * record overhead, see \c mbedtls_ssl_conf_mtu().
+ * record overhead, see \c mbedtls_ssl_set_mtu().
*
* \param conf SSL configuration
* \param mfl_code Code for maximum fragment length (allowed values:
@@ -2823,7 +2834,7 @@
* \note This function is not available (always returns an error)
* when record compression is enabled.
*
- * \sa mbedtls_ssl_conf_mtu()
+ * \sa mbedtls_ssl_set_mtu()
* \sa mbedtls_ssl_get_max_frag_len()
* \sa mbedtls_ssl_get_record_expansion()
*
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 05a2a9f..0b3fea1 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -110,7 +110,7 @@
static uint16_t ssl_get_maximum_datagram_size( mbedtls_ssl_context const *ssl )
{
- uint16_t mtu = ssl->conf->mtu;
+ uint16_t mtu = ssl->mtu;
if( mtu != 0 && mtu < MBEDTLS_SSL_OUT_BUFFER_LEN )
return( (int) mtu );
@@ -3120,7 +3120,7 @@
* - ssl->out_msg[0]: the handshake type (ClientHello, ServerHello, etc)
* - ssl->out_msg + 4: the handshake message body
*
- * Ouputs, ie state before passing to flight_append() or write_record():
+ * Outputs, ie state before passing to flight_append() or write_record():
* - ssl->out_msglen: the length of the record contents
* (including handshake headers but excluding record headers)
* - ssl->out_msg: the record contents (handshake headers + content)
@@ -6491,6 +6491,13 @@
ssl->f_recv_timeout = f_recv_timeout;
}
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+void mbedtls_ssl_set_mtu( mbedtls_ssl_context *ssl, uint16_t mtu )
+{
+ ssl->mtu = mtu;
+}
+#endif
+
void mbedtls_ssl_conf_read_timeout( mbedtls_ssl_config *conf, uint32_t timeout )
{
conf->read_timeout = timeout;
@@ -6979,13 +6986,6 @@
}
#endif
-#if defined(MBEDTLS_SSL_PROTO_DTLS)
-void mbedtls_ssl_conf_mtu( mbedtls_ssl_config *conf, uint16_t mtu )
-{
- conf->mtu = mtu;
-}
-#endif
-
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
int mbedtls_ssl_conf_max_frag_len( mbedtls_ssl_config *conf, unsigned char mfl_code )
{
@@ -7322,9 +7322,9 @@
#endif
#if defined(MBEDTLS_SSL_PROTO_DTLS)
- if( ssl->conf->mtu != 0 )
+ if( ssl->mtu != 0 )
{
- const size_t mtu = ssl->conf->mtu;
+ const size_t mtu = ssl->mtu;
const int ret = mbedtls_ssl_get_record_expansion( ssl );
const size_t overhead = (size_t) ret;
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index e723273..cfcb27d 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -1353,9 +1353,6 @@
mbedtls_ssl_conf_handshake_timeout( &conf, opt.hs_to_min,
opt.hs_to_max );
- if( opt.dtls_mtu != DFL_DTLS_MTU )
- mbedtls_ssl_conf_mtu( &conf, opt.dtls_mtu );
-
if( opt.dgram_packing != DFL_DGRAM_PACKING )
mbedtls_ssl_conf_datagram_packing( &ssl, opt.dgram_packing );
#endif /* MBEDTLS_SSL_PROTO_DTLS */
@@ -1516,6 +1513,11 @@
mbedtls_net_send, mbedtls_net_recv,
opt.nbio == 0 ? mbedtls_net_recv_timeout : NULL );
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+ if( opt.dtls_mtu != DFL_DTLS_MTU )
+ mbedtls_ssl_set_mtu( &ssl, opt.dtls_mtu );
+#endif
+
#if defined(MBEDTLS_TIMING_C)
mbedtls_ssl_set_timer_cb( &ssl, &timer, mbedtls_timing_set_delay,
mbedtls_timing_get_delay );
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 12f8276..4378e4f 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -2181,9 +2181,6 @@
if( opt.hs_to_min != DFL_HS_TO_MIN || opt.hs_to_max != DFL_HS_TO_MAX )
mbedtls_ssl_conf_handshake_timeout( &conf, opt.hs_to_min, opt.hs_to_max );
- if( opt.dtls_mtu != DFL_DTLS_MTU )
- mbedtls_ssl_conf_mtu( &conf, opt.dtls_mtu );
-
if( opt.dgram_packing != DFL_DGRAM_PACKING )
mbedtls_ssl_conf_datagram_packing( &ssl, opt.dgram_packing );
#endif /* MBEDTLS_SSL_PROTO_DTLS */
@@ -2505,6 +2502,11 @@
mbedtls_ssl_set_bio( &ssl, &client_fd, mbedtls_net_send, mbedtls_net_recv,
opt.nbio == 0 ? mbedtls_net_recv_timeout : NULL );
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+ if( opt.dtls_mtu != DFL_DTLS_MTU )
+ mbedtls_ssl_set_mtu( &ssl, opt.dtls_mtu );
+#endif
+
#if defined(MBEDTLS_TIMING_C)
mbedtls_ssl_set_timer_cb( &ssl, &timer, mbedtls_timing_set_delay,
mbedtls_timing_get_delay );
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index b6af4df..886c44c 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -5129,6 +5129,7 @@
requires_config_enabled MBEDTLS_RSA_C
requires_config_enabled MBEDTLS_ECDSA_C
run_test "DTLS fragmenting: both (MTU)" \
+ -p "$P_PXY mtu=512" \
"$P_SRV dtls=1 debug_level=2 auth_mode=required \
crt_file=data_files/server7_int-ca.crt \
key_file=data_files/server7.key \
@@ -5345,11 +5346,11 @@
"$P_SRV dgram_packing=0 dtls=1 debug_level=2 auth_mode=required \
crt_file=data_files/server7_int-ca.crt \
key_file=data_files/server7.key \
- mtu=512" \
+ hs_timeout=250-10000 mtu=512" \
"$P_CLI dgram_packing=0 dtls=1 debug_level=2 \
crt_file=data_files/server8_int-ca2.crt \
key_file=data_files/server8.key \
- mtu=512" \
+ hs_timeout=250-10000 mtu=512" \
0 \
-s "found fragmented DTLS handshake message" \
-c "found fragmented DTLS handshake message" \
@@ -5384,7 +5385,7 @@
"$P_CLI dtls=1 debug_level=2 \
crt_file=data_files/server8_int-ca2.crt \
key_file=data_files/server8.key \
- mtu=512 force_version=dtls1_2" \
+ mtu=512 force_version=dtls1" \
0 \
-c "fragmenting handshake message" \
-C "error"
@@ -5482,14 +5483,14 @@
requires_config_enabled MBEDTLS_RSA_C
requires_config_enabled MBEDTLS_ECDSA_C
requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
-client_needs_more_time 2
+client_needs_more_time 4
run_test "DTLS fragmenting: 3d, gnutls server, DTLS 1.2" \
-p "$P_PXY drop=8 delay=8 duplicate=8" \
"$G_NEXT_SRV -u" \
"$P_CLI dgram_packing=0 dtls=1 debug_level=2 \
crt_file=data_files/server8_int-ca2.crt \
key_file=data_files/server8.key \
- mtu=512 force_version=dtls1_2" \
+ hs_timeout=250-60000 mtu=512 force_version=dtls1_2" \
0 \
-c "fragmenting handshake message" \
-C "error"
@@ -5499,14 +5500,14 @@
requires_config_enabled MBEDTLS_RSA_C
requires_config_enabled MBEDTLS_ECDSA_C
requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_1
-client_needs_more_time 2
+client_needs_more_time 4
run_test "DTLS fragmenting: 3d, gnutls server, DTLS 1.0" \
-p "$P_PXY drop=8 delay=8 duplicate=8" \
"$G_NEXT_SRV -u" \
"$P_CLI dgram_packing=0 dtls=1 debug_level=2 \
crt_file=data_files/server8_int-ca2.crt \
key_file=data_files/server8.key \
- mtu=512 force_version=dtls1_2" \
+ hs_timeout=250-60000 mtu=512 force_version=dtls1" \
0 \
-c "fragmenting handshake message" \
-C "error"
@@ -5523,13 +5524,13 @@
## requires_config_enabled MBEDTLS_RSA_C
## requires_config_enabled MBEDTLS_ECDSA_C
## requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
-## client_needs_more_time 2
+## client_needs_more_time 4
## run_test "DTLS fragmenting: 3d, gnutls client, DTLS 1.2" \
## -p "$P_PXY drop=8 delay=8 duplicate=8" \
## "$P_SRV dtls=1 debug_level=2 server_addr=::1 \
## crt_file=data_files/server7_int-ca.crt \
## key_file=data_files/server7.key \
-## mtu=512 force_version=dtls1_2" \
+## hs_timeout=250-60000 mtu=512 force_version=dtls1_2" \
## "$G_CLI -u" \
## 0 \
## -s "fragmenting handshake message"
@@ -5540,13 +5541,13 @@
## requires_config_enabled MBEDTLS_RSA_C
## requires_config_enabled MBEDTLS_ECDSA_C
## requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_1
-## client_needs_more_time 2
+## client_needs_more_time 4
## run_test "DTLS fragmenting: 3d, gnutls client, DTLS 1.0" \
## -p "$P_PXY drop=8 delay=8 duplicate=8" \
## "$P_SRV dtls=1 debug_level=2 server_addr=::1 \
## crt_file=data_files/server7_int-ca.crt \
## key_file=data_files/server7.key \
-## mtu=512 force_version=dtls1" \
+## hs_timeout=250-60000 mtu=512 force_version=dtls1" \
## "$G_CLI -u" \
## 0 \
## -s "fragmenting handshake message"
@@ -5563,14 +5564,14 @@
## requires_config_enabled MBEDTLS_RSA_C
## requires_config_enabled MBEDTLS_ECDSA_C
## requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
-## client_needs_more_time 2
+## client_needs_more_time 4
## run_test "DTLS fragmenting: 3d, openssl server, DTLS 1.2" \
## -p "$P_PXY drop=8 delay=8 duplicate=8" \
## "$O_SRV -dtls1_2 -verify 10" \
## "$P_CLI dtls=1 debug_level=2 \
## crt_file=data_files/server8_int-ca2.crt \
## key_file=data_files/server8.key \
-## mtu=512 force_version=dtls1_2" \
+## hs_timeout=250-60000 mtu=512 force_version=dtls1_2" \
## 0 \
## -c "fragmenting handshake message" \
## -C "error"
@@ -5580,14 +5581,14 @@
requires_config_enabled MBEDTLS_RSA_C
requires_config_enabled MBEDTLS_ECDSA_C
requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_1
-client_needs_more_time 2
+client_needs_more_time 4
run_test "DTLS fragmenting: 3d, openssl server, DTLS 1.0" \
-p "$P_PXY drop=8 delay=8 duplicate=8" \
"$O_LEGACY_SRV -dtls1 -verify 10" \
"$P_CLI dgram_packing=0 dtls=1 debug_level=2 \
crt_file=data_files/server8_int-ca2.crt \
key_file=data_files/server8.key \
- mtu=512 force_version=dtls1" \
+ hs_timeout=250-60000 mtu=512 force_version=dtls1" \
0 \
-c "fragmenting handshake message" \
-C "error"
@@ -5597,13 +5598,13 @@
## requires_config_enabled MBEDTLS_RSA_C
## requires_config_enabled MBEDTLS_ECDSA_C
## requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
-## client_needs_more_time 2
+## client_needs_more_time 4
## run_test "DTLS fragmenting: 3d, openssl client, DTLS 1.2" \
## -p "$P_PXY drop=8 delay=8 duplicate=8" \
## "$P_SRV dtls=1 debug_level=2 \
## crt_file=data_files/server7_int-ca.crt \
## key_file=data_files/server7.key \
-## mtu=512 force_version=dtls1_2" \
+## hs_timeout=250-60000 mtu=512 force_version=dtls1_2" \
## "$O_CLI -dtls1_2" \
## 0 \
## -s "fragmenting handshake message"
@@ -5615,13 +5616,13 @@
requires_config_enabled MBEDTLS_RSA_C
requires_config_enabled MBEDTLS_ECDSA_C
requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_1
-client_needs_more_time 2
+client_needs_more_time 4
run_test "DTLS fragmenting: 3d, openssl client, DTLS 1.0" \
-p "$P_PXY drop=8 delay=8 duplicate=8" \
"$P_SRV dgram_packing=0 dtls=1 debug_level=2 \
crt_file=data_files/server7_int-ca.crt \
key_file=data_files/server7.key \
- mtu=512 force_version=dtls1" \
+ hs_timeout=250-60000 mtu=512 force_version=dtls1" \
"$O_LEGACY_CLI -nbio -dtls1" \
0 \
-s "fragmenting handshake message"
