This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Cloud Config 4.1.4!spring-doc.cn

Encryption and Decryption

To use the encryption and decryption features you need the full-strength JCE installed in your JVM (it is not included by default). You can download the “Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files” from Oracle and follow the installation instructions (essentially, you need to replace the two policy files in the JRE lib/security directory with the ones that you downloaded).

If the remote property sources contain encrypted content (values starting with {cipher}), they are decrypted before sending to clients over HTTP. The main advantage of this setup is that the property values need not be in plain text when they are “at rest” (for example, in a git repository). If a value cannot be decrypted, it is removed from the property source and an additional property is added with the same key but prefixed with invalid and a value that means “not applicable” (usually <n/a>). This is largely to prevent cipher text being used as a password and accidentally leaking.spring-doc.cn

If you set up a remote config repository for config client applications, it might contain an application.yml similar to the following:spring-doc.cn

application.yml

spring:
  datasource:
    username: dbuser
    password: '{cipher}FKSAJDFGYOS8F7GLHAKERGFHLSAJ'

Encrypted values in application.properties file must not be wrapped in quotes. Otherwise, the value is not decrypted. The following example shows values that would work:spring-doc.cn

application.properties

spring.datasource.username: dbuser
spring.datasource.password: {cipher}FKSAJDFGYOS8F7GLHAKERGFHLSAJ

You can safely push this plain text to a shared git repository, and the secret password remains protected.spring-doc.cn

The server also exposes /encrypt and /decrypt endpoints (on the assumption that these are secured and only accessed by authorized agents). If you edit a remote config file, you can use the Config Server to encrypt values by POSTing to the /encrypt endpoint, as shown in the following example:spring-doc.cn

$ curl localhost:8888/encrypt -s -d mysecret
682bc583f4641835fa2db009355293665d2647dade3375c0ee201de2a49f7bda

If you are testing with curl, then use --data-urlencode (instead of -d) and prefix the value to encrypt with = (curl requires this) or set an explicit Content-Type: text/plain to make sure curl encodes the data correctly when there are special characters ('+' is particularly tricky).

Be sure not to include any of the curl command statistics in the encrypted value, this is why the examples use the -s option to silence them. Outputting the value to a file can help avoid this problem.

The inverse operation is also available through /decrypt (provided the server is configured with a symmetric key or a full key pair), as shown in the following example:spring-doc.cn

$ curl localhost:8888/decrypt -s -d 682bc583f4641835fa2db009355293665d2647dade3375c0ee201de2a49f7bda
mysecret

Take the encrypted value and add the {cipher} prefix before you put it in the YAML or properties file and before you commit and push it to a remote (potentially insecure) store.spring-doc.cn

The /encrypt and /decrypt endpoints also both accept paths in the form of /*/{application}/{profiles}, which can be used to control cryptography on a per-application (name) and per-profile basis when clients call into the main environment resource.spring-doc.cn

To control the cryptography in this granular way, you must also provide a @Bean of type TextEncryptorLocator that creates a different encryptor per name and profiles. The one that is provided by default does not do so (all encryptions use the same key).

The spring command line client (with Spring Cloud CLI extensions installed) can also be used to encrypt and decrypt, as shown in the following example:spring-doc.cn

$ spring encrypt mysecret --key foo
682bc583f4641835fa2db009355293665d2647dade3375c0ee201de2a49f7bda
$ spring decrypt --key foo 682bc583f4641835fa2db009355293665d2647dade3375c0ee201de2a49f7bda
mysecret

To use a key in a file (such as an RSA public key for encryption), prepend the key value with "@" and provide the file path, as shown in the following example:spring-doc.cn

$ spring encrypt mysecret --key @${HOME}/.ssh/id_rsa.pub
AQAjPgt3eFZQXwt8tsHAVv/QHiY5sI2dRcR+...

The --key argument is mandatory (despite having a -- prefix).