Previously, MAC validation for an incoming record proceeded as follows:
1) Make a copy of the MAC contained in the record;
2) Compute the expected MAC in place, overwriting the presented one;
3) Compare both.
This resulted in a record buffer overflow if truncated MAC was used, as in this
case the record buffer only reserved 10 bytes for the MAC, but the MAC
computation routine in 2) always wrote a full digest.
For specially crafted records, this could be used to perform a controlled write of
up to 6 bytes past the boundary of the heap buffer holding the record, thereby
corrupting the heap structures and potentially leading to a crash or remote code
execution.
This commit fixes this by making the following change:
1) Compute the expected MAC in a temporary buffer that has the size of the
underlying message digest.
2) Compare to this to the MAC contained in the record, potentially
restricting to the first 10 bytes if truncated HMAC is used.
A similar fix is applied to the encryption routine `ssl_encrypt_buf`.
This commit adds regression tests for the bug when we didn't parse the
Signature Algorithm extension when renegotiating. (By nature, this bug
affected only the server)
The tests check for the fallback hash (SHA1) in the server log to detect
that the Signature Algorithm extension hasn't been parsed at least in
one of the handshakes.
A more direct way of testing is not possible with the current test
framework, since the Signature Algorithm extension is parsed in the
first handshake and any corresponding debug message is present in the
logs.
This commit adds regression tests for the bug when we didn't parse the
Signature Algorithm extension when renegotiating. (By nature, this bug
affected only the server)
The tests check for the fallback hash (SHA1) in the server log to detect
that the Signature Algorithm extension hasn't been parsed at least in
one of the handshakes.
A more direct way of testing is not possible with the current test
framework, since the Signature Algorithm extension is parsed in the
first handshake and any corresponding debug message is present in the
logs.
DTLS records from previous epochs were incorrectly checked against the
current epoch transform's minimal content length, leading to the
rejection of entire datagrams. This commit fixed that and adapts two
test cases accordingly.
Internal reference: IOTSSL-1417
It seems that tests from ssl-opt.sh are sometimes failing because
the server is killed before its output has been finalized. This commit
adds a small delay in ssl-opt.sh before killing the server to prevent
that.
ssl-opt.sh checks whether the client, server and proxy commands are
names of executable files, forbidding the use of default arguments by
by e.g. setting P_SRV="ssl_server2 debug_level=3". This commit relaxes
this check, only considering the part of the command string prior to
the first whitespace.
Add a test to ssl-opt.sh that parses the client and server debug
output and then checks that the Unix timestamp in the ServerHello
message is within acceptable bounds.
Extend the run_test function in ssl-opt.sh so that it accepts the -f
and -F options. These parameters take an argument which is the name of
a shell function that will be called by run_test and will be given the
client input and output debug log. The idea is that these functions are
defined by each test and they can be used to do some custom check
beyon those allowed by the pattern matching capabilities of the
run_test function.
Add a test to ssl-opt.sh that parses the client and server debug
output and then checks that the Unix timestamp in the ServerHello
message is within acceptable bounds.
Extend the run_test function in ssl-opt.sh so that it accepts the -f
and -F options. These parameters take an argument which is the name of
a shell function that will be called by run_test and will be given the
client input and output debug log. The idea is that these functions are
defined by each test and they can be used to do some custom check
beyon those allowed by the pattern matching capabilities of the
run_test function.
Some tests in ssl-opt.sh require MBEDTLS_SSL_MAX_CONTENT_LEN to be set to its
default value of 16384 to succeed. While ideally such a dependency should not
exist, as a short-term remedy this commit adds a small check that will at least
lead to graceful exit if that assumption is violated.
This commit adds four tests to ssl-opt.sh testing the library's behavior when
`mbedtls_ssl_write` is called with messages beyond 16384 bytes. The combinations
tested are TLS vs. DTLS and MBEDTLS_SSL_MAX_FRAGMENT_LENGTH enabled vs. disabled.
The tests only work for a specific number for MBEDTLS_X509_MAX_INTERMEDIATE_CA
so the check has been changed to confirm the default value, and to show an error
otherwise.
Some tests in ssl-opt.sh assumes the value 8 for the maximal number
MBEDTLS_X509_MAX_INTERMEDIATE_CA of intermediate CA's. This commit adds a check
before conducting the respective tests.
This commit adds four tests to tests/ssl-opt.sh:
(1) & (2): Check behaviour of optional/required verification when the
trusted CA chain is empty.
(3) & (4): Check behaviour of optional/required verification when the
client receives a server certificate with an unsupported curve.
* gilles/IOTSSL-1330/development:
Changelog entry for the bug fixes
SSLv3: when refusing renegotiation, stop processing
Ignore failures when sending fatal alerts
Cleaned up double variable declaration
Code portability fix
Added changelog entry
Send TLS alerts in many more cases
Skip all non-executables in run-test-suites.pl
SSL tests: server requires auth, client has no certificate
Balanced braces across preprocessor conditionals
Support setting the ports on the command line
By default, keep allowing SHA-1 in key exchange signatures. Disabling
it causes compatibility issues, especially with clients that use
TLS1.2 but don't send the signature_algorithms extension.
SHA-1 is forbidden in certificates by default, since it's vulnerable
to offline collision-based attacks.
Fixed a bug in ssl_srv.c when parsing TLS_FALLBACK_SCSV in the
ciphersuite list that caused it to miss it sometimes. Reported by Hugo
Leisink as issue #810. Fix initially by @andreasag01; this commit
isolates the bug fix and adds a non-regression test.
The TLS client and server code was usually closing the connection in
case of a fatal error without sending an alert. This commit adds
alerts in many cases.
Added one test case to detect that we send the alert, where a server
complains that the client's certificate is from an unknown CA (case
tracked internally as IOTSSL-1330).
Added command line arguments --port and --proxy-port to choose the
ports explicitly instead of deriving them from the PID. This
facilitates debugging e.g. with Wireshark.
Add a test to ssl-opt.sh to ensure that in DTLS a 6 byte record counter
is compared in ssl_check_ctr_renegotiate() instead of a 8 byte one as in
the TLS case. Because currently there are no testing facilities to check
that renegotiation routines are triggered after X number of input/output
messages, the test consists on setting a renegotiation period that
cannot be represented in 6 bytes, but whose least-significant byte is 2.
If the library behaves correctly, the renegotiation routines will be
executed after two exchanged.
In some tests in ssl-opt.sh the client finishes sooner and the server
gets killed before it could reach certain errors. Consequently the
the script doesn't find the error it is looking for and the test fails.
To resolve this issue, we introduce a per-test option to wait after the
client finishes.
Running valgrind on: "DTLS client reconnect from same port: reconnect,
nbio" results in timeouts.
New version added that runs only under valgrind. Original only runs when
valgrind is not used
The glibc package recently enabled compressed debug symbols but valgrind doesn't
support them yet.
Results in messages like:
--14923-- WARNING: Serious error when reading debug info
--14923-- When reading debug info from /lib/x86_64-linux-gnu/ld-2.21.so:
--14923-- Ignoring non-Dwarf2/3/4 block in .debug_info
First line has 'error' in it which triggers some of the ssl-opt tests
In order to reduce debugging time, allows you to only run interesting
tests (by number) from the commandline.
e.g. the command 'tests/ssl-opt.sh -n 246,258' will only run test 246
and 258 (as per the number in the log file names)
* development: (73 commits)
Bump yotta dependencies version
Fix typo in documentation
Corrected misleading fn description in ssl_cache.h
Corrected URL/reference to MPI library
Fix yotta dependencies
Fix minor spelling mistake in programs/pkey/gen_key.c
Bump version to 2.1.2
Fix CVE number in ChangeLog
Add 'inline' workaround where needed
Fix references to non-standard SIZE_T_MAX
Fix yotta version dependencies again
Upgrade yotta dependency versions
Fix compile error in net.c with musl libc
Add missing warning in doc
Remove inline workaround when not useful
Fix macroization of inline in C++
Changed attribution for Guido Vranken
Merge of IOTSSL-476 - Random malloc in pem_read()
Fix for IOTSSL-473 Double free error
Fix potential overflow in CertificateRequest
...
Conflicts:
include/mbedtls/ssl_internal.h
library/ssl_cli.c
This extension is quite costly to generate, and we don't want to re-do it
again when the server performs a DTLS HelloVerify. So, cache the result the
first time and re-use if/when we build a new ClientHello.
Note: re-send due to timeouts are different, as the whole message is cached
already, so they don't need any special support.
Let the client retry longer, to make sure the server will time out before the
client gives up. Make it really longer to get a deterministic client exit
status (make sure it has time to reconnect after the server timeout).
This is not very useful for TLS as mbedtls_ssl_write() will automatically
fragment and return the length used, and the application should check for that
anyway, but this is useful for DTLS where mbedtls_ssl_write() returns an
error, and the application needs to be able to query the maximum length
instead of just guessing.
Tends to cause spurious failures on buildbots due to peer timing out.
Anyway, those tests are mainly for interop, any memory error is most likely
catched by some earlier self-op test. (Also, we'll run these tests with ASan
anyway.)
Apparently openssl s_server does not flush stdout, anyway sometimes the client
receives the reply and exits, thus terminating the test, before is request is
visible on the server's stdout. So, just don't check that, checking the
client's output and exit code is already enough.
Retry one time in case we have a client timeout. These should be fairly rare
but still happen from time to time with udp_proxy tests which is annoying, and
until now has never indicated an actual issue.
Rather than flat-out die when we can't see the server started with lsof, just
stop waiting and try to go ahead with the test. Maybe it'll work if there was
a problem with lsof, most probably it will fail, but at least we'll have the
log, and the results of the following tests.
Note: date +%s isn't POSIX, but it works at least on Linux, Darwin/FreeBSD and
OpenBSD, which should be good enough for a test script.
This is not required nor recommended by the protocol, and it's a layering
violation, but it's a know flaw in the protocol that you can't detect a PSK
auth error in any other way, so it is probably the right thing to do.
closes#227
openssl s_server up to 1.0.2.a included uses a 512-bit prime for DH by
default. Since we now require 1024 bit at least, make s_server use decent
params. (1.0.2b and up use acceptable params by default.)
