Add signatory that supports GnuPG's gpg-agent

subprojects/docs/src/docs/userguide/signingPlugin.adoc

@@ -84,6 +84,48 @@ OpenPGP supports subkeys, which are like the normal keys, except they're bound t
 
 The signing plugin supports OpenPGP subkeys out of the box. Just specify a subkey ID as the value in the `signing.keyId` property.
 
+[[sec:using_gpg_agent]]
+=== Using gpg-agent
+
+By default the signing plugin uses a Java-based implementation of PGP for signing. This implementation cannot use the gpg-agent program for managing private keys, though. If you want to use the gpg-agent, you can change the signatory implementation used by the signing plugin to api:org.gradle.plugins.signing.signatory.gnupg.GnupgSignatory[].
+
+++++
+<sample id="useGnupg" dir="signing/gnupg-signatory" title="Sign with GnuPG">
+    <sourcefile file="build.gradle" snippet="configure-signatory" />
+</sample>
+++++
+
+This tells the signing plugin to use the `GnupgSignatory` instead of the default api:org.gradle.plugins.signing.signatory.pgp.PgpSignatory[]. The `GnupgSignatory` relies on the gpg2 progam to sign the artifacts. Of course, this requires that GnuPG is installed.
+
+Without any further configuration the `gpg2` (on Windows: `gpg2.exe`) executable found on the `PATH` will be used. The password is supplied by the `gpg-agent` and the default key is used for signing.
+
+
+[[sec:sec:gnupg_signatory_configuration]]
+==== Gnupg signatory configuration
+
+The `GnupgSignatory` supports a number of configuration options for controlling how gpg is invoked. These are typically set in gradle.properties:
+
+++++
+<sample id="configureGnupg" dir="signing/gnupg-signatory" title="Configure the GnupgSignatory">
+    <sourcefile file="gradle.properties" snippet="user-properties" />
+</sample>
+++++
+
+`signing.gnupg.executable`::
+The gpg executable that is invoked for signing. The default value of this property depends on `useLegacyGpg`. If that is `true` then the default value of executable is "gpg" otherwise it is "gpg2".
+`signing.gnupg.useLegacyGpg`::
+Must be `true` if GnuPG version 1 is used and `false` otherwise. The default value of the property is `false`.
+`signing.gnupg.homeDir`::
+Sets the home directory for GnuPG. If not given the default home directory of GnuPG is used.
+`signing.gnupg.optionsFile`::
+Sets a custom options file for GnuPG. If not given GnuPG's default configuration file is used.
+`signing.gnupg.keyName`::
+The id of the key that should be used for signing. If not given then the default key configured in GnuPG will be used.
+`signing.gnupg.passphrase`::
+The passphrase for unlocking the secret key. If not given then the gpg-agent program is used for getting the passphrase.
+
+All configuration properties are optional.
+
 [[sec:specifying_what_to_sign]]
 === Specifying what to sign
 

subprojects/docs/src/samples/signing/gnupg-signatory/build.gradle

@@ -0,0 +1,12 @@
+apply plugin: 'java'
+apply plugin: 'signing'
+
+group = 'gradle'
+version = '1.0'
+
+// START SNIPPET configure-signatory
+signing {
+    useGpgCmd()
+    sign configurations.archives
+}
+// END SNIPPET configure-signatory

subprojects/docs/src/samples/signing/gnupg-signatory/gradle.properties

@@ -0,0 +1,8 @@
+// START SNIPPET user-properties
+signing.gnupg.executable=gpg
+signing.gnupg.useLegacyGpg=true
+signing.gnupg.homeDir=gnupg-home
+signing.gnupg.optionsFile=gnupg-home/gpg.conf
+signing.gnupg.keyName=24875D73
+signing.gnupg.passphrase=gradle
+// END SNIPPET user-properties

subprojects/docs/src/samples/signing/gnupg-signatory/src/main/java/Sample.java

@@ -0,0 +1,2 @@
+class Sample {
+}

subprojects/docs/src/samples/signing/gnupg-signatory/src/main/resources/sample.txt

@@ -0,0 +1 @@
+some resource.

subprojects/signing/src/integTest/groovy/org/gradle/plugins/signing/GpgCmdFixture.groovy

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.gradle.plugins.signing
+
+import org.gradle.test.fixtures.file.TestFile
+
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.Paths
+
+class GpgCmdFixture {
+    private static final Random RANDOM = new Random()
+    private static final int ALL_DIGITS_AND_LETTERS_RADIX = 36
+    private static final int MAX_RANDOM_PART_VALUE = Integer.valueOf("zzzzz", ALL_DIGITS_AND_LETTERS_RADIX)
+
+    static String createRandomPrefix() {
+        return Integer.toString(RANDOM.nextInt(MAX_RANDOM_PART_VALUE), ALL_DIGITS_AND_LETTERS_RADIX)
+    }
+
+    static String getAvailableGpg() {
+        if (tryRun('gpg2')) {
+            return 'gpg2'
+        } else if (tryRun('gpg')) {
+            return 'gpg'
+        } else {
+            return null
+        }
+    }
+
+    static boolean tryRun(String cmd) {
+        try {
+            "${cmd} --version".execute()
+            return true
+        }
+        catch (IOException e) {
+            return false
+        }
+    }
+
+    static setupGpgCmd(TestFile buildDir) {
+        def gpgHomeSymlink = prepareGnupgHomeSymlink(buildDir.file('gnupg-home'))
+        Properties properties = new Properties()
+        properties.load(buildDir.file('gradle.properties').newInputStream())
+        String client = GpgCmdFixture.getAvailableGpg()
+        assert client
+        properties.put('signing.gnupg.executable', client)
+        properties.put('signing.gnupg.useLegacyGpg', (client == 'gpg').toString())
+        properties.put('signing.gnupg.homeDir', gpgHomeSymlink.toAbsolutePath().toString())
+        properties.remove('signing.gnupg.optionsFile')
+        properties.store(buildDir.file('gradle.properties').newOutputStream(), '')
+
+        return gpgHomeSymlink
+    }
+
+    static cleanupGpgCmd(def gpgHomeSymlink) {
+        Files.deleteIfExists(gpgHomeSymlink)
+    }
+
+    static prepareGnupgHomeSymlink(File gpgHomeInTest) {
+        // We have to do this, otherwise gpg will complain: can't connect to the agent: File name too long
+        // it's limited to 108 chars due to http://man7.org/linux/man-pages/man7/unix.7.html
+        Path tmpLink = Paths.get(System.getProperty("java.io.tmpdir")).resolve(createRandomPrefix())
+        return Files.createSymbolicLink(tmpLink, gpgHomeInTest.toPath())
+    }
+}

subprojects/signing/src/integTest/groovy/org/gradle/plugins/signing/SigningConfigurationsIntegrationSpec.groovy

@@ -16,7 +16,7 @@
 package org.gradle.plugins.signing
 
 class SigningConfigurationsIntegrationSpec extends SigningIntegrationSpec {
-    
+
     def "signing configurations"() {
         given:
         buildFile << """
@@ -25,22 +25,23 @@ class SigningConfigurationsIntegrationSpec extends SigningIntegrationSpec {
             }
 
             signing {
+                ${signingConfiguration()}
                 sign configurations.archives, configurations.meta
             }
 
             ${keyInfo.addAsPropertiesScript()}
             ${getJavadocAndSourceJarsScript("meta")}
         """
-        
+
         when:
         run "buildSignatures"
-        
+
         then:
         executedAndNotSkipped ":signArchives", ":signMeta"
-        
+
         and:
         file("build", "libs", "sign-1.0.jar.asc").text
         file("build", "libs", "sign-1.0-javadoc.jar.asc").text
         file("build", "libs", "sign-1.0-sources.jar.asc").text
     }
-}
+}

subprojects/signing/src/integTest/groovy/org/gradle/plugins/signing/SigningConfigurationsWithGpgCmdIntegrationSpec.groovy

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.gradle.plugins.signing
+
+import org.gradle.util.Requires
+
+@Requires(adhoc = { GpgCmdFixture.getAvailableGpg() != null })
+class SigningConfigurationsWithGpgCmdIntegrationSpec extends SigningConfigurationsIntegrationSpec {
+    SignMethod getSignMethod() {
+        return SignMethod.GPG_CMD
+    }
+}

subprojects/signing/src/integTest/groovy/org/gradle/plugins/signing/SigningIntegrationSpec.groovy

@@ -17,14 +17,24 @@ package org.gradle.plugins.signing
 
 import org.gradle.integtests.fixtures.AbstractIntegrationSpec
 import org.gradle.integtests.fixtures.TestResources
+import org.gradle.integtests.fixtures.executer.IntegrationTestBuildContext
+import org.gradle.test.fixtures.file.TestFile
 import org.junit.Rule
 
+import java.nio.file.Path
+
 import static org.gradle.util.TextUtil.escapeString
 
 abstract class SigningIntegrationSpec extends AbstractIntegrationSpec {
-
+    enum SignMethod {
+        OPEN_GPG,
+        GPG_CMD
+    }
+
     @Rule public final TestResources resources = new TestResources(temporaryFolder, "keys")
 
+    Path gpgHomeSymlink
+
     String jarFileName = "sign-1.0.jar"
 
     def setup() {
@@ -35,17 +45,42 @@ abstract class SigningIntegrationSpec extends AbstractIntegrationSpec {
             group = 'sign'
             version = '1.0'
         """
-        
+
         file("src", "main", "java", "Thing.java") << """
             public class Thing {}
         """
+
+        if (getSignMethod() == SignMethod.GPG_CMD) {
+            setupGpgCmd()
+        }
+    }
+
+    def setupGpgCmd() {
+        TestFile sampleDir = new IntegrationTestBuildContext().getSamplesDir()
+        sampleDir.file('signing/gnupg-signatory/gnupg-home').copyTo(file('gnupg-home'))
+        sampleDir.file('signing/gnupg-signatory/gradle.properties').copyTo(file('gradle.properties'))
+        GpgCmdFixture.setupGpgCmd(temporaryFolder.testDirectory)
+    }
+
+    def cleanup() {
+        if (gpgHomeSymlink != null) {
+            GpgCmdFixture.cleanupGpgCmd(gpgHomeSymlink)
+        }
+    }
+
+    def signingConfiguration() {
+        if (getSignMethod() == SignMethod.OPEN_GPG) {
+            return ''
+        } else {
+            return 'useGpgCmd()'
+        }
     }
 
     static class KeyInfo {
         String keyId
         String password
         String keyRingFilePath
-        
+
         Map<String, String> asProperties(String name = null) {
             def prefix = name ? "signing.${name}." : "signing."
             def properties = [:]
@@ -54,22 +89,22 @@ abstract class SigningIntegrationSpec extends AbstractIntegrationSpec {
             properties[prefix + "secretKeyRingFile"] = keyRingFilePath
             properties
         }
-        
+
         String addAsPropertiesScript(addTo = "project.ext", name = null) {
             asProperties(name).collect { k, v ->
                 "${addTo}.setProperty('${escapeString(k)}', '${escapeString(v)}')"
             }.join(";")
         }
     }
-    
+
     KeyInfo getKeyInfo(set = "default") {
         new KeyInfo(
             keyId: file(set, "keyId.txt").text.trim(),
             password: file(set, "password.txt").text.trim(),
             keyRingFilePath: file(set, "secring.gpg")
         )
     }
-    
+
     String getJavadocAndSourceJarsScript(String configurationName = null) {
         def tasks = """
             task("sourcesJar", type: Jar, dependsOn: classes) { 
@@ -82,7 +117,7 @@ abstract class SigningIntegrationSpec extends AbstractIntegrationSpec {
                 from javadoc.destinationDir 
             } 
         """
-        
+
         if (configurationName == null) {
             tasks
         } else {
@@ -97,7 +132,7 @@ abstract class SigningIntegrationSpec extends AbstractIntegrationSpec {
             """
         }
     }
-    
+
     String uploadArchives() {
         return """
             apply plugin: "maven"
@@ -168,12 +203,16 @@ abstract class SigningIntegrationSpec extends AbstractIntegrationSpec {
             }
         """
     }
-    
+
     File pom(String name = "sign-1.0") {
         m2RepoFile("${name}.pom")
     }
 
     File pomSignature(String name = "sign-1.0") {
         m2RepoFile("${name}.pom.asc")
     }
-}
+
+    SignMethod getSignMethod() {
+        return SignMethod.OPEN_GPG
+    }
+}