The server must check client reachability (we chose to do that by checking a
cookie) before destroying the existing association (RFC 6347 section 4.2.8).
Let's make sure we do, by having a proxy-in-the-middle inject a ClientHello -
the server should notice, but not destroy the connection.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
The ssl-opt.sh test cases using session resumption tend to fail occasionally
on the CI due to a race condition in how ssl_server2 and ssl_client2 handle
the reconnection cycle.
The server does the following in order:
- S1 send application data
- S2 send a close_notify alert
- S3 close the client socket
- S4 wait for a "new connection" (actually a new datagram)
- S5 start a handshake
The client does the following in order:
- C1 wait for and read application data from the server
- C2 send a close_notify alert
- C3 close the server socket
- C4 reset session data and re-open a server socket
- C5 start a handshake
If the client has been able to send the close_notify (C2) and if has been
delivered to the server before if closes the client socket (S3), when the
server reaches S4, the datagram that we start the new connection will be the
ClientHello and everything will be fine.
However if S3 wins the race and happens before the close_notify is delivered,
in S4 the close_notify is what will be seen as the first datagram in a new
connection, and then in S5 this will rightfully be rejected as not being a
valid ClientHello and the server will close the connection (and go wait for
another one). The client will then fail to read from the socket and exit
non-zero and the ssl-opt.sh harness will correctly report this as a failure.
In order to avoid this race condition in test using ssl_client2 and
ssl_server2, this commits introduces a new command-line option
skip_close_notify to ssl_client2 and uses it in all ssl-opt.sh tests that use
session resumption with DTLS and ssl_server2.
This works because ssl_server2 knows how many messages it expects in each
direction and in what order, and closes the connection after that rather than
relying on close_notify (which is also why there was a race in the first
place).
Tests that use another server (in practice there are two of them, using
OpenSSL as a server) wouldn't work with skip_close_notify, as the server won't
close the connection until the client sends a close_notify, but for the same
reason they don't need it (there is no race between receiving close_notify and
closing as the former is the cause of the later).
An alternative approach would be to make ssl_server2 keep the connection open
until it receives a close_notify. Unfortunately it creates problems for tests
where we simulate a lossy network, as the close_notify could be lost (and the
client can't retransmit it). We could modify udp_proxy with an option to never
drop alert messages, but when TLS 1.3 comes that would no longer work as the
type of messages will be encrypted.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
You can't reuse a CTR_DRBG context without free()ing it and
re-init()ing it. This generally happened to work, but was never
guaranteed. It could have failed with alternative implementations of
the AES module because mbedtls_ctr_drbg_seed() calls
mbedtls_aes_init() on a context which is already initialized if
mbedtls_ctr_drbg_seed() hasn't been called before, plausibly causing a
memory leak. Calling free() and seed() with no intervening init fails
when MBEDTLS_THREADING_C is enabled and all-bits-zero is not a valid
mutex representation. So add the missing free() and init().
Add a very basic test of calloc to the selftest program. The selftest
program acts in its capacity as a platform compatibility checker rather
than in its capacity as a test of the library.
The main objective is to report whether calloc returns NULL for a size
of 0. Also observe whether a free/alloc sequence returns the address
that was just freed and whether a size overflow is properly detected.
* restricted/pr/581:
Remove unnecessary empty line
Add a test for signing content with a long ECDSA key
Add documentation notes about the required size of the signature buffers
Add missing MBEDTLS_ECP_C dependencies in check_config.h
Change size of preallocated buffer for pk_sign() calls
If `make TEST_CPP:=1` is run, and then `make clean` (as opposed to `make
TEST_CPP:=1 clean`), the cpp_dummy_build will be left behind after the
clean. Make `make clean more convenient to use by removing programs that
could be generated from any configuration, not just the active one.
Fixes#1862
* origin/pr/2482:
Document support for MD2 and MD4 in programs/x509/cert_write
Correct name of X.509 parsing test for well-formed, ill-signed CRT
Add test cases exercising successful verification of MD2/MD4/MD5 CRT
Add test case exercising verification of valid MD2 CRT
Add MD[245] test CRTs to tree
Add instructions for MD[245] test CRTs to tests/data_files/Makefile
Add suppport for MD2 to CSR and CRT writing example programs
Convert further x509parse tests to use lower-case hex data
Correct placement of ChangeLog entry
Adapt ChangeLog
Use SHA-256 instead of MD2 in X.509 CRT parsing tests
Consistently use lower case hex data in X.509 parsing tests
* origin/pr/2498:
Adapt ChangeLog
ssl_server2: Fail gracefully if no PEM-encoded CRTs are available
ssl_server2: Skip CA setup if `ca_path` or `ca_file` argument "none"
ssl_client2: Fail gracefully if no PEM-encoded CRTs are available
ssl_client2: Skip CA setup if `ca_path` or `ca_file` argument "none"
To prevent dropping the same message over and over again, the UDP proxy
test application programs/test/udp_proxy _logically_ maintains a mapping
from records to the number of times the record has already been dropped,
and stops dropping once a configurable threshold (currently 2) is passed.
However, the actual implementation deviates from this logical view
in two crucial respects:
- To keep the implementation simple and independent of
implementations of suitable map interfaces, it only counts how
many times a record of a given _size_ has been dropped, and
stops dropping further records of that size once the configurable
threshold is passed. Of course, this is not fail-proof, but a
good enough approximation for the proxy, and it allows to use
an inefficient but simple array for the required map.
- The implementation mixes datagram lengths and record lengths:
When deciding whether it is allowed to drop a datagram, it
uses the total datagram size as a lookup index into the map
counting the number of times a package has been dropped. However,
when updating this map, the UDP proxy traverses the datagram
record by record, and updates the mapping at the level of record
lengths.
Apart from this inconsistency, the current implementation suffers
from a lack of bounds checking for the parsed length of incoming
DTLS records that can lead to a buffer overflow when facing
malformed records.
This commit removes the inconsistency in datagram vs. record length
and resolves the buffer overflow issue by not attempting any dissection
of datagrams into records, and instead only counting how often _datagrams_
of a particular size have been dropped.
There is only one practical situation where this makes a difference:
If datagram packing is used by default but disabled on retransmission
(which OpenSSL has been seen to do), it can happen that we drop a
datagram in its initial transmission, then also drop some of its records
when they retransmitted one-by-one afterwards, yet still keeping the
drop-counter at 1 instead of 2. However, even in this situation, we'll
correctly count the number of droppings from that point on and eventually
stop dropping, because the peer will not fall back to using packing
and hence use stable record lengths.
The example programs programs/x509/cert_req and programs/x509/cert_write
(demonstrating the use of X.509 CSR and CRT writing functionality)
previously didn't support MD2 signatures.
For testing purposes, this commit adds support for MD2 to cert_req,
and support for MD2 and MD4 to cert_write.
Remove the ssl_cert_test sample application, as it uses
hardcoded certificates that moved, and is redundant with the x509
tests and applications. Fixes#1905.
This allows to test PSK-based ciphersuites via ssl_server2 in builds
which have MBEDTLS_X509_CRT_PARSE_C enabled but both MBEDTLS_FS_IO and
MBEDTLS_CERTS_C disabled.
This allows to test PSK-based ciphersuites via ssl_client2 in builds
which have MBEDTLS_X509_CRT_PARSE_C enabled but both MBEDTLS_FS_IO and
MBEDTLS_CERTS_C disabled.
A similar change is applied to the `crt_file` and `key_file` arguments.
When MBEDTLS_MEMORY_BUFFER_ALLOC_C was defined, the sample ssl_server2.c was
using its own memory buffer for memory allocated by the library. The memory
used wasn't obvious, so this adds a macro for the memory buffer allocated to
make the allocated memory size more obvious and hence easier to configure.
Newer features in the library have increased the overall RAM usage of the
library, when all features are enabled. ssl_server2.c, with all features enabled
was running out of memory for the ssl-opt.sh test 'Authentication: client
max_int chain, server required'.
This commit increases the memory buffer allocation for ssl_server2.c to allow
the test to work with all features enabled.
This commit replaces multiple `memset()` calls in the example
programs aes/aescrypt2.c and aes/crypt_and_hash.c by calls to
the reliable zeroization function `mbedtls_zeroize()`.
While not a security issue because the code is in the example
programs, it's bad practice and should be fixed.
If `MBEDTLS_MEMORY_BUFFER_ALLOC_C` is configured and Mbed TLS'
custom buffer allocator is used for calloc() and free(), the
read buffer used by the server example application is allocated
from the buffer allocator, but freed after the buffer allocator
has been destroyed. If memory backtracing is enabled, this leaves
a memory leak in the backtracing structure allocated for the buffer,
as found by valgrind.
Fixes#2069.
* The variables `csr` and `issuer_crt` are initialized but not freed.
* The variable `entropy` is unconditionally freed in the cleanup section
but there's a conditional jump to that section before its initialization.
This cmmot Moves it to the other initializations happening before the
first conditional jump to the cleanup section.
Fixes#1422.
Changes the IP address to bind to for dtls_server.c to be "::" or optionally
"0.0.0.0" if the preprocessor symbol FORCE_IPV4 is defined.
Also changes the destinaton IP address for dtls_client.c to be "::1" or if
FORCE_IPV4 symbol is defined "127.0.0.1".
This change allows on compilation dtls_server.c and dtls_client.c to both be
compiled to use either IPv4 or IPv6 so out of the box they will work together
without problem, and to avoid dtls_server.c binding to IPv6 and dtls_client.c
binding to IPv4.
