# TLS-based Authentication

TLS authentication is disabled in the default version of UniConfig.

To enable TLS for RESTCONF, perform the following two steps:

Set up key-store and trust-store to hold all keys and certificates. If authentication of individual clients is not required, trust-store is also not required. Key-store must always be initialized.
Enable TLS in UniConfig via the application.properties configuration file.

# Set key-store and trust-store

To prepare key-store and trust-store:

In the UniConfig root directory, create a new directory that will contain key-store and, optionally, trust-store files. For example:

mkdir ./tls
cd ./tls

Create a new key-store. There are two options depending on whether you already own the certificate that you want to use for identification of UniConfig on the RESTCONF layer:
1. Create a new key-store with the generated RSA key-pair (the example below uses a length of 2048 and validity of 365 days). After executing the following command, the prompt will ask you for information about the currently generated certificate that is pushed into the newly generated key-store secured by a password (this secret will be used later in the configuration file - make sure that you remember it).
```
keytool -keystore .keystore -alias jetty -genkey -keyalg RSA -storetype PKCS12 -validity 365 -keysize 2048
```
1. Create a new key-store with the already-generated RSA key-pair (your certificate that you want to use for authentication in ODL).
```
keytool -import -file [your-certificate-file] -alias jetty -keystore .keystore
```
(Optional step) Create a new trust-store using an existing certificate (an empty trust-store cannot be created). If you have multiple client certificates, they can be pushed to trust-store by executing the same command multiple times (the alias must be unique for each of the imported certificates). For example:

keytool -import -file [client-app-certificate] -alias [unique-name-of-certificate] -keystore .truststore

You can easily convert OPENSSL PEM certificates to the DER format supported by keytool:

openssl x509 -outform der -in certificate.pem -out certificate.der

If your application must own the distribution's certificate, you can export the certificate from the generated key-pair that we have pushed into the keystore (PKCS12 or OPENSSL format):

keytool -export -keystore .keystore -alias jetty -file odl.cer
openssl pkcs12 -in .keystore -out certificate.pem

# Enable TLS in UniConfig

After preparing key-store and trust-store, you need to point UniConfig to these storages and explicitly enable TLS via a flag.

Modify the following configuration file at a path relative to the UniConfig root directory:

vim config/application.properties

Next, edit the TLS configuration section, un-commenting and editing the relevant properties.

The example snippet below enables TLS authentication, disables user-based authentication (hence trust-store is not required) and points UniConfig to the key-store file created in the previous section:

# TLS settings
server.http2.enabled=true
server.ssl.enabled=true
server.ssl.protocol=TLS
server.ssl.client-auth=none
server.ssl.enabled-protocols=TLSv1.2,TLSv1.3
#server.ssl.ciphers=
#server.ssl.trust-store=tls/.truststore
#server.ssl.trust-store-password=trust-pass
server.ssl.key-store=tls/.keystore
server.ssl.key-store-password=passtest
# Enable SNI
#server.ssl.sni-enabled=true

If your deployment requires authentication for individual RESTCONF users, trust-store is required and you need to set server.ssl.client-auth=need

# TLS settings
server.http2.enabled=true
server.ssl.enabled=true
server.ssl.protocol=TLS
server.ssl.client-auth=need
#server.ssl.enabled-protocols=TLSv1.2,TLSv1.3
#server.ssl.ciphers=
server.ssl.trust-store=tls/.truststore
server.ssl.trust-store-password=trust-pass
server.ssl.key-store=tls/.keystore
server.ssl.key-store-password=passtest
# Enable SNI
#server.ssl.sni-enabled=true

JVM provides secure defaults, which you can override by specifying included cipher suites and TLS versions.

The following example configuration includes support for TLS 1.2 and TLS 1.3 with some of the most common and strongest ciphers available:

server.ssl.enabled-protocols=TLSv1.2,TLSv1.3
server.ssl.ciphers=TLS_AES_128_GCM_SHA256,TLS_AES_256_GCM_SHA384,TLS_CHACHA20_POLY1305_SHA256, TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256

SNI (Server Name Indication) is disabled by default. To enable it, uncomment the line below:

# Enable SNI
server.ssl.sni-enabled=true