Instead of skipping the verification during handshake,
tls_allow_invalid_server_certificate will be unset during
initialization of the connection handle if environment varible
MARIADB_TLS_DISABLE_PEER_VERIFICATION was set.
This will allow drivers and applications which don't have an API
option to enable/disable peer server certificate verification
to start without TLS/SSL.
- moved fingerprint verification to ma_tls.c
- don't verify cert again if fingerprint check
succeeded.
- Disable self signed check in fingerprint tests
(Schannel only).
For testing purposes (the python3 dummy server can't handle
further communication after TLS handshake succeeded) support
for verification callback was added.
my_bool callback(MYSQL *mysql, unsigned int *flags, my_bool verified)
Parameter:
- mysql connection handle for current connection
- flags verification flags
- verified true if callback was called after verification,
otherwise false
Return value:
- False (0) to continue
- True (1) to abort tls connection
The callback function can be registered via
mysql_optionsv(mysql, MARIADB_OPT_TLS_VERIFICATION_CALLBACK, callback);
* fix comments
* reorder errors to put hard errors on top
* report errors from openssl
* don't overwrite errors in C/C
* pass correct flags to gnutls_x509_crt_check_hostname2()
* use the same define name everywhere consistently
* don't recalculate fingerprint in openssl unnecessary
* misc
Peer certificate validation:
Since version 3.4 peer certificate verification is enabled by default.
It can be disabled via `mysql_optionsv`, using option
MYSQL_OPT_SSL_VERIFY_SERVER_CERT:
my_bool verify= 0;
mysql_options(mariadb, MYSQL_OPT_SSL_VERIFY_SERVER_CERT, &verify);
Self signed certificates
If the client obtained a self signed peer certificate from MariaDB server
the verification will fail, with the following exceptions:
* If the connection between client and server is considered to be secure:, e.g.
* a unix_socket is used for client server communication
* hostname is localhost (Windows operating system), 127.0.0.1 or ::1
* a specified fingerprint matches the fingerprint of the peer certificate (see below)
* a client can verify the certificate using account password, it's possible if
* account has a password
* authentication plugin is "secure without TLS", that is, one of
mysql_native_password, ed25519 or parsec.
Fingerprint verification of the peer certificate
A fingerprint is a cryptographic hash (SHA-256, SHA-384 or SHA-512) of the peer
certificate's binary data. Even if the fingerprint matches, an expired or
revoked certificate will not be accepted.
For security reasons support for MD5 and SHA1 has been removed.
Technical details:
==================
- Peer certificate verification call was removed from ma_tls_connect, instead it
will be called directly after the handshake succeeded (my_auth.c)
- mysql->net.tls_self_signed_error was replaced by mysql->net.tls_verify_status which
contains the result of the peer certfificate verification:
The verification status can be obtained with mariadb_get_infov using new parameter
MARIADB_TLS_VERIFY_STATUS.
unsigned int tls_verify_status;
mariadb_get_infov(mysql, MARIADB_TLS_VERIFY_STATUS, &tls_verify_status);
The result is a combination of the following flags:
MARIADB_TLS_VERIFY_OK 0
MARIADB_TLS_VERIFY_TRUST 1
MARIADB_TLS_VERIFY_HOST 2
MARIADB_TLS_VERIFY_PERIOD 4
MARIADB_TLS_VERIFY_FINGERPRINT 8
MARIADB_TLS_VERIFY_REVOKED 16
MARIADB_TLS_VERIFY_UNKNOWN 32
- GnuTLS peer certificate verification callback was removed and replaced by
gnutls_verify_peers2() api function, so the peer certificate validation
will happen after handshake.
- OpenSSL implementation will no longer use SSL_verify_result to check the
validity of the peer certificate. Instead a callback function will be called
during the handshake, which collects all certificate validation errors.
- If the peer certificate is not trusted, hostname verification will be
skipped.
- Testing
Added new test tls, which implements a python based dummy server, which allows
to set different certificates and TLS options. Please note. that tests are
expected to fail, since the server doesn't support further steps like user
authentication etc. after the handshake. Prerequisite for running the tls test
is Python3.
POWER and other architectures that define char(as my_bool) to be unsigned (as the C
standard leaves this undefined). This resulted in error branches being
unreachabe as indicated by the below compile warnings.
plugins/pvio/pvio_socket.c:763:42: warning: comparison of constant -1 with expression of type 'my_bool' (aka 'char') is always
false [-Wtautological-constant-out-of-range-compare]
if (pvio_socket_blocking(pvio, 1, 0) == SOCKET_ERROR)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~
plugins/pvio/pvio_socket.c:875:46: warning: comparison of constant -1 with expression of type 'my_bool' (aka 'char') is always
false [-Wtautological-constant-out-of-range-compare]
if (pvio_socket_blocking(pvio, 0, 0) == SOCKET_ERROR)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~
plugins/pvio/pvio_socket.c:907:42: warning: comparison of constant -1 with expression of type 'my_bool' (aka 'char') is always
false [-Wtautological-constant-out-of-range-compare]
if (pvio_socket_blocking(pvio, 1, 0) == SOCKET_ERROR)
ma_hext2int: signed char - prevent compiler errors when char is unsigned.
libmariadb/ma_tls.c:169:31: warning: comparison of constant -1 with expression of type 'char' is always false
[-Wtautological-constant-out-of-range-compare]
if ((d1 = ma_hex2int(*p)) == - 1 ||
~~~~~~~~~~~~~~~~~~~~~ ^ ~~~
libmariadb/ma_tls.c:170:35: warning: comparison of constant -1 with expression of type 'char' is always false
[-Wtautological-constant-out-of-range-compare]
(d2 = ma_hex2int(*(p+1))) == -1 ||
~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~
To fix this all the pvio_*_blocking functions have been changed to use
int as a return value.
Other my_bool/char differences fixed:
mariadb_dyncol_val_str: fix prototype to use char - like implemented function.
unittest: bind.is_null is my_bool* so we use a my_bool.
Client part of MDEV-14101: Add support for tls-version, via
mysql_options(mysql, MARIADB_OPT_TLS_VERSION, value)
Accepted values are "TLSv1.1", "TLSv1.2" and "TLSv1.3".
Fixed testcase openssl_1 for schannel
When calling mariadb_get_infov with option MARIADB_TLS_LIBRARY
the functioni now returns the correct version number and name
of the tls/ssl library in use.
- don't use password in global context
- load keys and certs via callback functions
- don't use gnutls_bye since server is not able to detect dead socket
- fixed valgrind errors in gnutls
- TLS/SSL: renamed HAVE_SSL to HAVE_TLS to avoid trouble in
10.2-integration
- Fixed wrong timeout in non-blocking mode
- Fixed valgrind error in prepared statement
