Provided by: libmongoc-doc_1.21.0-1build1_all 
NAME
mongoc_configuring_tls - Configuring TLS
CONFIGURATION WITH URI OPTIONS
Enable TLS by including tls=true in the URI.
mongoc_uri_t *uri = mongoc_uri_new ("mongodb://localhost:27017/");
mongoc_uri_set_option_as_bool (uri, MONGOC_URI_TLS, true);
mongoc_client_t *client = mongoc_client_new_from_uri (uri);
The following URI options may be used to further configure TLS:
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└─────────────────────────────────────────────────┴──────────────────────────────────────┴────────────────────────────────────────┘
CONFIGURATION WITH MONGOC_SSL_OPT_T
Alternatively, the mongoc_ssl_opt_t struct may be used to configure TLS with mongoc_client_set_ssl_opts()
or mongoc_client_pool_set_ssl_opts(). Most of the configurable options can be set using the Connection
String URI.
────────────────────────────────────────────────────────────
│ mongoc_ssl_opt_t key │ URI key │
├────────────────────────┼─────────────────────────────────┤
│ pem_file │ tlsClientCertificateKeyFile │
├────────────────────────┼─────────────────────────────────┤
│ pem_pwd │ tlsClientCertificateKeyPassword │
├────────────────────────┼─────────────────────────────────┤
│ ca_file │ tlsCAFile │
├────────────────────────┼─────────────────────────────────┤
│ weak_cert_validation │ tlsAllowInvalidCertificates │
├────────────────────────┼─────────────────────────────────┤
│ allow_invalid_hostname │ tlsAllowInvalidHostnames │
└────────────────────────┴─────────────────────────────────┘
The only exclusions are crl_file and ca_dir. Those may only be set with mongoc_ssl_opt_t.
CLIENT AUTHENTICATION
When MongoDB is started with TLS enabled, it will by default require the client to provide a client
certificate issued by a certificate authority specified by --tlsCAFile, or an authority trusted by the
native certificate store in use on the server.
To provide the client certificate, set the tlsCertificateKeyFile in the URI to a PEM armored certificate
file.
mongoc_uri_t *uri = mongoc_uri_new ("mongodb://localhost:27017/");
mongoc_uri_set_option_as_bool (uri, MONGOC_URI_TLS, true);
mongoc_uri_set_option_as_utf8 (uri, MONGOC_URI_TLSCERTIFICATEKEYFILE, "/path/to/client-certificate.pem");
mongoc_client_t *client = mongoc_client_new_from_uri (uri);
SERVER CERTIFICATE VERIFICATION
The MongoDB C Driver will automatically verify the validity of the server certificate, such as issued by
configured Certificate Authority, hostname validation, and expiration.
To overwrite this behavior, it is possible to disable hostname validation, OCSP endpoint revocation
checking, revocation checking entirely, and allow invalid certificates.
This behavior is controlled using the tlsAllowInvalidHostnames, tlsDisableOCSPEndpointCheck,
tlsDisableCertificateRevocationCheck, and tlsAllowInvalidCertificates options respectively. By default,
all are set to false.
It is not recommended to change these defaults as it exposes the client to Man In The Middle attacks
(when tlsAllowInvalidHostnames is set), invalid certificates (when tlsAllowInvalidCertificates is set),
or potentially revoked certificates (when tlsDisableOCSPEndpointCheck or
tlsDisableCertificateRevocationCheck are set).
SUPPORTED LIBRARIES
By default, libmongoc will attempt to find a supported TLS library and enable TLS support. This is
controlled by the cmake flag ENABLE_SSL, which is set to AUTO by default. Valid values are:
• AUTO the default behavior. Link to the system's native TLS library, or attempt to find OpenSSL.
• DARWIN link to Secure Transport, the native TLS library on macOS.
• WINDOWS link to Secure Channel, the native TLS library on Windows.
• OPENSSL link to OpenSSL (libssl). An optional install path may be specified with OPENSSL_ROOT.
• LIBRESSL link to LibreSSL's libtls. (LibreSSL's compatible libssl may be linked to by setting OPENSSL).
• OFF disable TLS support.
OpenSSL
The MongoDB C Driver uses OpenSSL, if available, on Linux and Unix platforms (besides macOS). Industry
best practices and some regulations require the use of TLS 1.1 or newer, which requires at least OpenSSL
1.0.1. Check your OpenSSL version like so:
$ openssl version
Ensure your system's OpenSSL is a recent version (at least 1.0.1), or install a recent version in a
non-system path and build against it with:
cmake -DOPENSSL_ROOT_DIR=/absolute/path/to/openssl
When compiled against OpenSSL, the driver will attempt to load the system default certificate store, as
configured by the distribution. That can be overridden by setting the tlsCAFile URI option or with the
fields ca_file and ca_dir in the mongoc_ssl_opt_t.
The Online Certificate Status Protocol (OCSP) (see RFC 6960) is fully supported when using OpenSSL 1.0.1+
with the following notes:
• When a crl_file is set with mongoc_ssl_opt_t, and the crl_file revokes the server's certificate, the
certificate is considered revoked (even if the certificate has a valid stapled OCSP response)
LibreSSL / libtls
The MongoDB C Driver supports LibreSSL through the use of OpenSSL compatibility checks when configured to
compile against openssl. It also supports the new libtls library when configured to build against
libressl.
When compiled against the Windows native libraries, the crl_file option of a mongoc_ssl_opt_t is not
supported, and will issue an error if used.
Setting tlsDisableOCSPEndpointCheck and tlsDisableCertificateRevocationCheck has no effect.
The Online Certificate Status Protocol (OCSP) (see RFC 6960) is partially supported with the following
notes:
• The Must-Staple extension (see RFC 7633) is ignored. Connection may continue if a Must-Staple
certificate is presented with no stapled response (unless the client receives a revoked response from
an OCSP responder).
• Connection will continue if a Must-Staple certificate is presented without a stapled response and the
OCSP responder is down.
Native TLS Support on Windows (Secure Channel)
The MongoDB C Driver supports the Windows native TLS library (Secure Channel, or SChannel), and its
native crypto library (Cryptography API: Next Generation, or CNG).
When compiled against the Windows native libraries, the ca_dir option of a mongoc_ssl_opt_t is not
supported, and will issue an error if used.
Encrypted PEM files (e.g., setting tlsCertificateKeyPassword) are also not supported, and will result in
error when attempting to load them.
When tlsCAFile is set, the driver will only allow server certificates issued by the authority (or
authorities) provided. When no tlsCAFile is set, the driver will look up the Certificate Authority using
the System Local Machine Root certificate store to confirm the provided certificate.
When crl_file is set with mongoc_ssl_opt_t, the driver will import the revocation list to the System
Local Machine Root certificate store.
Setting tlsDisableOCSPEndpointCheck has no effect.
The Online Certificate Status Protocol (OCSP) (see RFC 6960) is partially supported with the following
notes:
• The Must-Staple extension (see RFC 7633) is ignored. Connection may continue if a Must-Staple
certificate is presented with no stapled response (unless the client receives a revoked response from
an OCSP responder).
• When a crl_file is set with mongoc_ssl_opt_t, and the crl_file revokes the server's certificate, the
OCSP response takes precedence. E.g. if the server presents a certificate with a valid stapled OCSP
response, the certificate is considered valid even if the crl_file marks it as revoked.
• Connection will continue if a Must-Staple certificate is presented without a stapled response and the
OCSP responder is down.
Native TLS Support on macOS / Darwin (Secure Transport)
The MongoDB C Driver supports the Darwin (OS X, macOS, iOS, etc.) native TLS library (Secure Transport),
and its native crypto library (Common Crypto, or CC).
When compiled against Secure Transport, the ca_dir and crl_file options of a mongoc_ssl_opt_t are not
supported. An error is issued if either are used.
When tlsCAFile is set, the driver will only allow server certificates issued by the authority (or
authorities) provided. When no tlsCAFile is set, the driver will use the Certificate Authorities in the
currently unlocked keychains.
Setting tlsDisableOCSPEndpointCheck and tlsDisableCertificateRevocationCheck has no effect.
The Online Certificate Status Protocol (OCSP) (see RFC 6960) is partially supported with the following
notes.
• The Must-Staple extension (see RFC 7633) is ignored. Connection may continue if a Must-Staple
certificate is presented with no stapled response (unless the client receives a revoked response from
an OCSP responder).
• Connection will continue if a Must-Staple certificate is presented without a stapled response and the
OCSP responder is down.
AUTHOR
MongoDB, Inc
COPYRIGHT
2017-present, MongoDB, Inc
1.21.0 Feb 09, 2022 MONGOC_CONFIGURING_TLS(3)