Enabling HostName Verification
The possibility to configure hostname verification is available for WSO2 products from Carbon 4.4.6 onwards. If hostname verification is disabled for your product, the hostnames (that are accessed by a particular client) will not be verified against the hostnames specified in the product's SSL certificate. If hostname verification is enabled, you will be able to configure how hostnames are filtered during the verification process.
See the following topics for details:
Important!
Be sure to enable hostname verification for your production environment. This is necessary to avoid security issues in production. See the full list of security recommendations for production environments.
Hostname verification is enabled by default in WSO2 EI 6.6.0. This is done using the httpclien
t.hostnameVerifier
 property in the product's startup script as shown below. The product startup script is stored in the /bin
 directory for each profile. This property will be effective during server startup.
-Dhttpclient.hostnameVerifier="DefaultAndLocalhost"
The values you can use with this property are explained below. Note that these values will behave the same as synapse hostname verification options.
DefaultAndLocalhost: This is the value that is enabled, by default. This means that all hostnames, except the ones listed below, will be verified against the hostnames specified in the product's SSL certificate. That is, the following hostnames will be allowed regardless of the server's certificate.
localhost
localhost.localdomain
127.0.0.1
::1Â
Note that if the wildcard symbol is used to specify a hostname in the SSL certificate (such as *.foo.com), all the subdomains of *.foo.com are also included. That is, a hostname that matches a subdomain of *.foo.com will also be allowed access.
Strict:Â When this mode is enabled, hostnames will be strictly verified against the hostname specified in the product's SSL certificate. For example, if "*.foo.com" is specified as the hostname in the certificate, only the hostnames at the same level will be authorized by the server. That is, subdomains such as "a.b.foo.com" will not be authorized.
AllowAll:Â This option turns off hostname verification for the server. Note that this is not recommended in a production setup and should only be used for demonstrations and testing.