Facebook Hash Generator for Android Gradle Console

build.gradle

def getFacebookHash = { ->
    try {
        def stdOut = new ByteArrayOutputStream()
        def stdIn = new ByteArrayInputStream()
        exec {

            commandLine "keytool", "-exportcert", "-alias", KEY_ALIAS, "-keystore", file(STORE_FILE), "-storepass", STORE_PASSWORD
            standardOutput = stdOut
        }
        stdIn = new ByteArrayInputStream(stdOut.toByteArray())
        stdOut = new ByteArrayOutputStream()
        exec {
            standardInput = stdIn
            commandLine file(OPENSSL_BINARY), "sha1", "-binary"
            standardOutput = stdOut
        }
        stdIn = new ByteArrayInputStream(stdOut.toByteArray())
        stdOut = new ByteArrayOutputStream()
        exec {
            standardInput = stdIn
            commandLine file(OPENSSL_BINARY), "base64"
            standardOutput = stdOut
        }
        def hashString = stdOut.toString().trim()
        return hashString
    }
    catch (error) {
        return error.toString();
    }
}

gradle.buildFinished {
    println "Facebook Release Key Hash:\n  " + getFacebookHash() + "\n"
}

gradle.properties

STORE_FILE=C:/Keystore.jks
STORE_PASSWORD=password
KEY_ALIAS=keystoreAlias
KEY_PASSWORD=password
OPENSSL_BINARY=C:/OpenSSL-Win64/bin/openssl