Gradle plugin to store and access encrypted credentials for use in Gradle builds.
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README.md

gradle-credentials-plugin

Overview

Gradle plugin that allows to store and access encrypted credentials using password-based encryption (PBE).

The credentials plugin is hosted at Bintray's JCenter.

Goals

One typical use case of the 'gradle.properties' file in the Gradle user home directory is to store credentials, and to reference them from Gradle builds as project properties. This is a very convenient functionality at the cost that, by default, these properties are stored in plain text. It happens quickly that such credentials are exposed accidentally while giving a Gradle presentation or while pair-programming with a colleague.

The credentials plugin provides a parallel functionality to the 'gradle.properties' file to store and access credentials in an encrypted format through a 'gradle.encrypted.properties' files, thereby avoiding that credentials are ever stored in plain text.

Functionality

The following functionality is provided by the credentials plugin:

  • Store encrypted credentials
  • Delete encrypted credentials
  • Access encrypted credentials from a Gradle build

Design

All access and storage of credentials goes through password-based encryption. The passphrase can either be specified as a project property from the command line, or a default passphrase is used. The JDK encryption algorithm applied is AES using a key that is generated using PBKDF2WithHmacSHA1 from an 8-byte salt, an iteration count of 65536, and a key length of 128 (longer keys require local installation of the JRE Security Extension).

Access to the stored credentials from within a Gradle build happens through the credentials project property. All read and write operations to the credentials container apply the decryption and encryption on the fly. The credentials container never holds any credentials in their decrypted form.

Please note that the author of this plugin is by far not a security expert. It is also not the primary goal of this plugin to provide high-security encryption, but rather to provide a convenient way to avoid having to store credentials in plain text.

Configuration

Apply credentials plugin

Apply the nu.studer.credentials plugin to your Gradle plugin project.

Gradle 1.x and 2.0

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'nu.studer:gradle-credentials-plugin:1.0.6'
    }
}

apply plugin: 'nu.studer.credentials'

Gradle 2.1 and higher

plugins {
  id 'nu.studer.credentials' version '1.0.6'
}

Please refer to the Gradle DSL PluginDependenciesSpec to understand the behavior and limitations when using the new syntax to declare plugin dependencies.

Invoke credentials tasks

Store encrypted credentials

You can store new credentials or update existing credentials through the addCredentials task. Pass along the credentials key and value through the task options --key and --value. The credentials are stored in the GRADLE_USER_HOME/gradle.encrypted.properties.

gradle addCredentials --key someKey --value someValue

Optionally, pass along a custom passphrase through the credentialsPassphrase project property. The credentials are stored in the passphrase-specific GRADLE_USER_HOME/gradle.MD5HASH.encrypted.properties where the MD5HASH is calculated from the specified passphrase.

gradle addCredentials --key someKey --value someValue -PcredentialsPassphrase=mySecretPassPhrase

Remove encrypted credentials

You can remove existing credentials through the removeCredentials task. Pass along the credentials key through the --key project property. The credentials are removed from the GRADLE_USER_HOME/gradle.encrypted.properties.

gradle removeCredentials --key someKey

Optionally, pass along a custom passphrase through the credentialsPassphrase project property. The credentials are removed from the passphrase-specific GRADLE_USER_HOME/gradle.MD5HASH.encrypted.properties where the MD5HASH is calculated from the specified passphrase.

gradle removeCredentials --key someKey -PcredentialsPassphrase=mySecretPassPhrase

Access credentials in build

Get credentials from within a build

Get the desired credentials from the credentials container, available on the project instance. The credentials are decrypted as they are accessed.

String accountPassword = credentials.someAccountName

If no explicit passphrase is passed when starting the build, the credentials container is initialized with all credentials persisted in the GRADLE_USER_HOME/gradle.encrypted.properties.

If a custom passphrase is passed through the credentialsPassphrase project property when starting the build, the credentials container is initialized with all credentials persisted in the passphrase-specific GRADLE_USER_HOME/gradle.MD5HASH.encrypted.properties where the MD5HASH is calculated from the specified passphrase.

Add credentials ad-hoc from within a build

Set the desired credentials on the credentials container, available on the project instance. The credentials are encrypted as they are assigned.

credentials.someAccountName = 'verySecret'

Credentials added ad-hoc during the build are not persisted on the file system.

Example

The build script of the credentials plugin makes use of itself and serves as a real-world example. You can also find a self-contained example build script here.

Feedback and Contributions

Both feedback and contributions are very welcome.

Acknowledgements

License

This plugin is available under the Apache License, Version 2.0.

(c) by Etienne Studer