add build metadata to jar file to aid reproducible builds

This moves jar creation to `ant release`.

To provide build security, it should be possible for anyone to run the
build process and end up with the same result as Zetetic.  To aid that
process, this adds metadata to the release jar that specifies which
versions of Java, Android SDK, and Android NDK were used to build the
official release.

Author: eighthave

Makefile

@@ -32,9 +32,7 @@ build-jni:
 	ndk-build NDK_LIBS_OUT=$(JNI_DIR)/libs
 
 build-java:
-	ant release && \
-	cd ${CURDIR}/bin/classes && \
-	jar -cvf sqlcipher.jar .
+	ant release
 
 release:
 	-rm -rf ${RELEASE_DIR}
@@ -71,7 +69,6 @@ copy-libs:
 		 ${LIBRARY_ROOT}/armeabi  && \
 	cp ${JNI_DIR}/libs/armeabi/libdatabase_sqlcipher.so \
 		${LIBRARY_ROOT}/armeabi && \
-	cp ${CURDIR}/bin/classes/sqlcipher.jar ${LIBRARY_ROOT} && \
 	cp ${EXTERNAL_DIR}/libs/armeabi/libstlport_shared.so \
 		 ${LIBRARY_ROOT}/armeabi
 	mkdir -p ${LIBRARY_ROOT}/x86

custom_rules.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project name="custom_rules">
+
+  <condition property="ndk.dir" value="${env.ANDROID_NDK}">
+    <isset property="env.ANDROID_NDK" />
+  </condition>
+
+  <target name="-getgitdetails" >
+    <exec executable="git" outputproperty="git.describe">
+      <arg value="describe"/>
+    </exec>
+    <exec executable="git" outputproperty="git.revision">
+      <arg value="rev-parse"/>
+      <arg value="HEAD"/>
+    </exec>
+  </target>
+
+  <target name="-post-build" depends="-getgitdetails">
+    <property name="jar.dir" value="libs" />
+    <property name="jar.name" value="${jar.dir}/sqlcipher.jar" />
+    <property file="${sdk.dir}/tools/source.properties" />
+    <exec executable="cat" outputproperty="ndk.release">
+      <arg value="${ndk.dir}/RELEASE.TXT"/>
+    </exec>
+    <delete file="${jar.name}"/>
+    <mkdir dir="${jar.dir}" />
+    <jar destfile="${jar.name}"
+         includes="net/sqlcipher/**"
+         basedir="${out.classes.absolute.dir}">
+      <manifest>
+        <attribute name="Implementation-Vendor" value="Zetetic"/>
+        <attribute name="Implementation-Title" value="SQLCipher for Android"/>
+        <attribute name="Implementation-URL" value="https://www.zetetic.net/sqlcipher/open-source"/>
+        <attribute name="Implementation-Version" value="${git.describe}"/>
+        <attribute name="Git-Revision" value="${git.revision}"/>
+        <attribute name="Android-SDK-Release" value="${Pkg.Revision}"/>
+        <attribute name="Android-SDK-Host-OS" value="${Archive.HostOs}"/>
+        <attribute name="Android-NDK-Release" value="${ndk.release}"/>
+      </manifest>
+    </jar>
+  </target>
+
+</project>