Provided by: trafficserver_5.3.0-2ubuntu2_amd64 
NAME
ssl_multicert.config - Traffic Server SSL certificate configuration file
The ssl_multicert.config file lets you configure Traffic Server to use multiple SSL server certificates
to terminate the SSL sessions. If you have a Traffic Server system with more than one IP address assigned
to it, then you can assign a different SSL certificate to be served when a client requests a particular
IP address or host name.
At configuration time, certificates are parsed to extract the certificate subject and all the DNS subject
alternative names. A certificate will be presented for connections requesting any of the hostnames found
in the certificate. Wildcard names are supported, but only of the form *.domain.com, ie. where * is the
leftmost domain component.
Changes to ssl_multicert.config can be applied to a running Traffic Server using traffic_line -x.
FORMAT
Each ssl_multicert.config line consists of a sequence of key=value fields that specify how Traffic Server
should use a particular SSL certificate.
ssl_cert_name=FILENAME[,FILENAME ...]
The name of the file containing the TLS certificate. FILENAME is located relative to the directory
specified by the proxy.config.ssl.server.cert.path configuration variable. It may also include
the intermediate CA certificates, sorted from leaf to root. At a minimum, the file must include a
leaf certificate.
When running with OpenSSL 1.0.2 or later, this directive can be used to configure the intermediate
CA chain on a per-certificate basis. Multiple chain files are separated by comma character. For
example, it is possible able to configure a ECDSA certificate chain and a RSA certificate chain
and serve them simultaneously, allowing OpenSSL to determine which certificate would be used when
the TLS session cipher suites are negotiated. Note that the leaf certs in FILENAME1 and FILENAME2
must have the same subjects and alternate names. The first certificate is used to to match the
client's SNI request.
You can also configure multiple leaf certificates in a same chain with OpenSSL 1.0.1.
This is the only field that is required to be present.
dest_ip=ADDRESS (optional)
The IP (v4 or v6) address that the certificate should be presented on. This is now only used as a
fallback in the case that the TLS SubjectNameIndication extension is not supported. If ADDRESS is
*, the corresponding certificate will be used as the global default fallback if no other match can
be made. The address may contain a port specifier, in which case the corresponding certificate
will only match for connections accepted on the specified port. IPv6 addresses must be enclosed
by square brackets if they have a port, eg, [::1]:80. Care should be taken to make each ADDRESS
unique.
ssl_key_name=FILENAME (optional)
The name of the file containing the private key for this certificate. If the key is contained in
the certificate file, this field can be omitted, otherwise FILENAME is resolved relative to the
proxy.config.ssl.server.private_key.path configuration variable.
ssl_ca_name=FILENAME (optional)
If the certificate is issued by an authority that is not in the system CA bundle, additional
certificates may be needed to validate the certificate chain. FILENAME is resolved relative to the
proxy.config.ssl.CA.cert.path configuration variable.
ssl_ticket_enabled=1|0 (optional)
Enable RFC 5077 stateless TLS session tickets. To support this, OpenSSL should be upgraded to
version 0.9.8f or higher. This option must be set to 0 to disable session ticket support.
ticket_key_name=FILENAME (optional)
The name of session ticket key file which contains a secret for encrypting and decrypting TLS
session tickets. If FILENAME is not an absolute path, it is resolved relative to the
proxy.config.ssl.server.cert.path configuration variable. This option has no effect if session
tickets are disabled by the ssl_ticket_enabled option. The contents of the key file should be 48
random bytes.
Session ticket support is enabled by default. If neither of the ssl_ticket_enabled and
ticket_key_name options are specified, and internal session ticket key is generated. This key will
be different each time Traffic Server is started.
ssl_key_dialog=builtin|"exec:/path/to/program [args]" (optional)
Method used to provide a pass phrase for encrypted private keys. If the pass phrase is incorrect,
SSL negotiation for this dest_ip will fail for clients who attempt to connect. Two options are
supported: builtin and exec:
builtin - Requests pass phrase via stdin/stdout. User will be
provided the ssl_cert_name and be prompted for the pass phrase. Useful for debugging.
exec: - Executes program /path/to/program and passes args, if
specified, to the program and reads the output from stdout for the pass phrase. If args
are provided then the entire exec: string must be quoted with "" (see examples).
Arguments with white space are supported by single quoting ('). The intent is that this
program runs a security check to ensure that the system is not compromised by an
attacker before providing the pass phrase.
CERTIFICATE SELECTION
Traffic Server attempts two certificate selections during SSL connection setup. An initial selection is
made when a TCP connection is accepted. This selection examines the IP address and port that the client
is connecting to and chooses the best certificate from the those that have a dest_ip specification. If no
matching certificates are found, a default certificate is chosen. The final certificate selection is
made during the SSL handshake. At this point, the client may use Server Name Indication to request a
specific hostname. Traffic Server will use this request to select a certificate with a matching subject
or subject alternative name. Failing that, a wildcard certificate match is attempted. If no match can be
made, the initial certificate selection remains in force.
In all cases, Traffic Server attempts to select the most specific match. An address specification that
contains a port number will take precedence over a specification that does not contain a port number. A
specific certificate subject will take precedence over a wildcard certificate. In the case of multiple
matching certificates the first match will be returned to non-SNI capable clients.
EXAMPLES
The following example configures Traffic Server to use the SSL certificate server.pem for all requests to
the IP address 111.11.11.1 and the SSL certificate server1.pem for all requests to the IP address
11.1.1.1. Connections from all other IP addresses are terminated with the default.pem certificate. Since
the private key is included in the certificate files, no private key name is specified.
dest_ip=111.11.11.1 ssl_cert_name=server.pem
dest_ip=11.1.1.1 ssl_cert_name=server1.pem
dest_ip=* ssl_cert_name=default.pem
The following example configures Traffic Server to use the ECDSA certificate chain ecdsa.pem or RSA
certificate chain rsa.pem for all requests.
dest_ip=* ssl_cert_name=ecdsa.pem,rsa.pem
The following example configures Traffic Server to use the ECDSA certificate chain ecdsa.pem or RSA
certificate chain rsa.pem for all requests, the public key and private key are in separate PEM files.
Note that the number of files in ssl_key_name must match the files in ssl_cert_name, and they should be
presented in the same order.
dest_ip=* ssl_cert_name=ecdsa_pub.pem,rsa_pub.pem ssl_key_name=ecdsa_private.pem,rsa_private.pem
The following example configures Traffic Server to use the SSL certificate server.pem and the private key
serverKey.pem for all requests to port 8443 on IP address 111.11.11.1. The general.pem certificate is
used for server name matches.
dest_ip=111.11.11.1:8443 ssl_cert_name=server.pem ssl_key_name=serverKey.pem ssl_cert_name=general.pem
The following example configures Traffic Server to use the SSL certificate server.pem for all requests to
the IP address 111.11.11.1. Session tickets are enabled with a persistent ticket key.
dest_ip=111.11.11.1 ssl_cert_name=server.pem ssl_ticket_enabled=1 ticket_key_name=ticket.key
The following example configures Traffic Server to use the SSL certificate server.pem and disable session
tickets for all requests to the IP address 111.11.11.1.
dest_ip=111.11.11.1 ssl_cert_name=server.pem ssl_ticket_enabled=0
The following examples configure Traffic Server to use the SSL certificate server.pem which includes an
encrypted private key. The external program /usr/bin/mypass will be called on startup with one parameter
(foo) in the first example, and with two parameters (foo) and (ba r) in the second example, the program
(mypass) will return the pass phrase to decrypt the keys.
ssl_cert_name=server1.pem ssl_key_dialog="exec:/usr/bin/mypass foo"
ssl_cert_name=server2.pem ssl_key_dialog="exec:/usr/bin/mypass foo 'ba r'"
COPYRIGHT
2014, dev@trafficserver.apache.org
5.3 April 18, 2016 SSL_MULTICERT.CONFIG(5)