WSO2 products use asymmetric encryption by default for the authentication and protection of data. In asymmetric encryption, keystores (with private keys and public key certificates) and truststores (with only public key certificates) are created and stored for a product. It is possible to have multiple keystores so that the keys used for different use cases are kept unique. The following topics explain more details on keystores and truststores, and how they are used in WSO2 products.
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Understanding keystores and truststores
A keystore is a repository (protected by a password) that holds the keys and certificates of a trust chain. There may be multiple trust chains (i.e., multiple keys with corresponding certificates) in one keystore. You use these artifacts for security purposes such as protecting sensitive information and establishing trust between your server and outside parties that connect to
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the server. The usage of keys and certificates contained in
a keystore are explained below.
Key pairsKeys: According to public-key cryptography, the concept of a key pair (private public key and the corresponding public private key) is used for encrypting protecting sensitive information and for authenticating the identity of external parties that communicate with your server. For example, the information that is encrypted in your server using the public key can only be decrypted using the corresponding private key. Therefore, if any party wants to decrypt this encrypted data, they should have the corresponding private key, which is usually kept as a secret (not publicly shared).
Digital certificate: When there is a key pair, it is also necessary to have a digital certificate to verify the identity of the keys. Typically, the public key of a key pair is embedded in this digital certificate, which also contains additional information such as the owner, validity, etc. of the keys. For example, if an external party wants to verify the integrity of data or validate the identity of the signer (by validating the digital signature), it is necessary for them to have this digital certificate of the signer.
Trusted certificates and certificate signing authorities: To establish trust, the digital certificate containing the public key should be signed by a trusted certifying certificate signing authority (CA). You can generate self-signed certificates for the public key (thereby creating your own certifying authority), or you can get the certificates signed by the digital certificate of an external CA. Both types of trusted certificates can be effectively used depending on the sensitivity of the information that is protected by the keys. When the When the certificate is signed by a reputed CA, all the parties who that trust this CA will also trust the certificates signed by them.
The key pair and the CA-signed certificates in a keystore establishes two security functions in your server: The key pair with the digital certificate is an indication of identity and the CA-signed certificate provides trust to the identity. Since the public key is used to encrypt information, the keystore containing the corresponding private key should always be protected, as it can decrypt the sensitive information. Furthermore, the privacy of the private key is important as it represents its own identity and protects the integrity of data. However, the CA-signed digital certificates should be accessible to outside parties that require to decrypt and use the information.
To facilitate this requirement, the certificates must be copied to a separate keystore (called a Truststore), which can then be shared with outside parties. Therefore, in a typical setup, you will have one keystore for identity (containing the private key) that is protected, and a separate keystore for trust (containing CA certificates) that is shared with outside parties.
Setting up keystores for WSO2 products
In WSO2 products, public key encryption is used To establish maximum trust, it is important to have a root CA directly sign your public key certificate, or else, you can have an intermediate CA certificate (which is already signed by a root CA) sign your certificate. Therefore, in the later case, there can be a chain of CAs involved in signing your public key certificate. However, note that both types of public key certificates (self-signed or CA-signed) can be effectively used depending on the sensitivity of the information that is protected by the keys.
In summary, each trust chain entry in a keystore contains the following:
- A private key protected by a password.
- A digital certificate in which the public key (corresponding to the private key) is embedded.
- Additionally, If this public key certificate is not self-signed but signed by a Certificate Signing Authority (CA), an additional set of certificates (of the CAs involved in the signing process) will also be included. This may be just one additional certificate if the immediate CA certificate that was used to sign the public key certificate is of a Root CA. If the immediate certificate is not of a root CA, all the certificates of the intermediate CAs should also be included in the keystore.
The usage of a truststore in WSO2 products aligns with this concept of trust explained above. A truststore is just another repository that is protected by a password (similar to a keystore), which stores digital certificates. These certificates can be either of the following:
- Certificates of trusted third parties with which a software system intends to communicate directly.
- Certificates of reputed certificate signing authorities (CA) that can be used to validate the identity of untrusted third parties that are being contacted. For example, consider a scenario where the exact certificate of the third party that the WSO2 server is attempting to contact is not in the truststore. In this scenario, if the third party has a CA-signed certificate and one of the certificates of its trust chain is already included in the WSO2 server's truststore, the trust is automatically granted and a successful SSL connection is established between the WSO2 server and the third party.
Default keystore and truststore in WSO2 products
All WSO2 products are by default shipped with a keystore file and truststore file (stored in the
wso2carbon.jks: This is the default keystore, which contains a private key and the self-signed public key certificate.
.jks: This is the default truststore, which contains certificates of reputed CAs that can validate the identity of third party systems. This truststore also contains the self-signed certificate of the default
In WSO2 products, asymmetric encryption is used by default for the following purposes:
- Authenticating the communication over Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocols.
Encrypting sensitive information
data such as plain
as plain-text passwords found in both product-level and product feature-level configurations/configuration files using secure vault.
- Encrypting data such as scripts, configuration files, xmld, xsds etc. into the registry.Encrypting/signing in
- and signing SOAP messages using WS-Security.
The default keystore that is shipped with a WSO2 product (
trust chains for the above use cases
Follow the recommendations given below when you set up your keystores.
Maintain one primary keystore for encrypting sensitive internal data such as admin passwords and certain registry data. By default, the primary keystore is also used for WS-Security and for authenticating Tomcat level connections.Maintain a separate keystore for authenticating the
any other sensitive information found at both product-level and product feature-level configurations/configuration files.
Maintain another secondary keystore, containing the server’s public key certificate for authenticating communication over SSL/TLS (for both Tomcat and Axis2 level HTTP connections).
- Optionally, you can set up separate keystores with key pairs and certificates for WS-Security.
- A separate keystore (truststore) for the purpose of storing the trusted certificates of public keys in your keystores.
If your deployment contains multiple products, instances of the same product must use the same keystore for SSL. Different products can use different keystores for SSL, but it is not mandatory.
It is recommended to use a CA-signed keystore for SSL communication; however, this is not mandatory. Even a self-signed certificate may suffice if it can be trusted by the clients.
The keystore used for SSL must contain the same password for the Keystore and private key due to a Tomcat limitation.
The primary keystore used for admin passwords and other data encryption requirements can be a self-signed one. There is no value added by using a CA-signed keystore for this purpose as it is not used for any external communication.
The primary keystore's public key certificate must have the Data Encipherment key usage to allow direct encipherment of raw data using its public key. This key usage is already included in the self-signed certificate that is included in the default
wso2carbon.jks keystore. If the Data Encipherment key usage is not included in your public key certificate, the following error can occur when you attempt data encryption:
Exception in thread "main" org.wso2.ciphertool.CipherToolException: Error initializing Cipher at org.wso2.ciphertool.CipherTool.handleException(CipherTool.java:861) at org.wso2.ciphertool.CipherTool.initCipher(CipherTool.java:202) at org.wso2.ciphertool.CipherTool.main(CipherTool.java:80) Caused by: java.security.InvalidKeyException: Wrong key usage at javax.crypto.Cipher.init(DashoA13..) at javax.crypto.Cipher.init(DashoA13..) at org.wso2.ciphertool.CipherTool.initCipher(CipherTool.java:200) ... 1 more
Optionally, you can set up separate keystores for message-level data encryption in WS-Security.
For information on creating new keystores with the required certificates, see Creating New Keystores,
and for information
on how to update configuration files in your product
Default keystore settings in WSO2 products
All WSO2 products are shipped with two default keystore files stored in the
wso2carbon.jks: This keystore contains a key pair and is used by default in your Carbon server for all of the purposes explained above.
client-truststore.jks: This is the default trust store, which contains the trusted certificates of the keystore used in SSL communication.
It is recommended to replace this default keystore with a new keystore that has self-signed or CA signed certificates when the products are deployed in production environments. This is because wso2carbon.jks is available with open source WSO2 products, which means anyone can have access to the private key of the default keystore.
All the functions of keystore management are exposed via APIs. As a result, if you are writing a custom extension to a WSO2 product (e.g., for WSO2 ESB mediators), you can directly access the configured keystores using the API. The API hides the underlying complexity, allowing you to easily use it in third-party applications to manage their keystores as well.
Name: WSO2 Carbon - Security Management Feature
Note the following regarding WSO2 keystore management: