diff --git a/.gitattributes b/.gitattributes
index b965efe99..a777ac7f7 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -8,6 +8,7 @@
 
 # Declare files that will always have CRLF line endings on checkout.
 *.cmd text eol=crlf
+*.bat text eol=crlf
 
 # Denote all files that are truly binary and should not be modified.
 chromeos/** binary
diff --git a/build.py b/build.py
index 04f40ee64..4b45311c5 100755
--- a/build.py
+++ b/build.py
@@ -122,8 +122,17 @@ def build_apk(args):
 		if proc.returncode != 0:
 			error('Zipalign Magisk Manager failed!')
 
-		proc = subprocess.run('{} sign --ks {} --out {} {}'.format(
-			'java -jar {}'.format(os.path.join('../ziptools/apksigner.jar')),
+		# Find apksigner.jar
+		apksigner = ''
+		for root, dirs, files in os.walk(os.path.join(os.environ['ANDROID_HOME'], 'build-tools', build_tool)):
+			if 'apksigner.jar' in files:
+				apksigner = os.path.join(root, 'apksigner.jar')
+				break
+		if not apksigner:
+			error('Cannot find apksigner.jar in Android SDK build tools')
+
+		proc = subprocess.run('java -jar {} sign --ks {} --out {} {}'.format(
+			apksigner,
 			os.path.join('..', 'release_signature.jks'),
 			release, aligned), shell=True)
 		if proc.returncode != 0:
@@ -140,20 +149,33 @@ def build_apk(args):
 	os.chdir('..')
 
 def sign_adjust_zip(unsigned, output):
-	header('* Signing / Adjusting Zip')
 
-	# Unsigned->signed
-	proc = subprocess.run(['java', '-jar', os.path.join('ziptools', 'signapk.jar'),
-		os.path.join('ziptools', 'public.certificate.x509.pem'),
-		os.path.join('ziptools', 'private.key.pk8'), unsigned, 'tmp_signed.zip'])
-	if proc.returncode != 0:
-		error('First sign flashable zip failed!')
+	zipsigner = os.path.join('ziptools', 'zipsigner', 'build', 'libs', 'zipsigner.jar')
 
 	if os.name != 'nt' and not os.path.exists(os.path.join('ziptools', 'zipadjust')):
+		header('* Building zipadjust')
 		# Compile zipadjust
-		proc = subprocess.run('gcc -o ziptools/zipadjust ziptools/src/*.c -lz', shell=True)
+		proc = subprocess.run('gcc -o ziptools/zipadjust ziptools/zipadjust_src/*.c -lz', shell=True)
 		if proc.returncode != 0:
 			error('Build zipadjust failed!')
+	if not os.path.exists(zipsigner):
+		header('* Building zipsigner.jar')
+		os.chdir(os.path.join('ziptools', 'zipsigner'))
+		proc = subprocess.run('{} shadowJar'.format(os.path.join('.', 'gradlew')), shell=True)
+		if proc.returncode != 0:
+			error('Build zipsigner.jar failed!')
+		os.chdir(os.path.join('..', '..'))
+
+	header('* Signing / Adjusting Zip')
+
+	publicKey = os.path.join('ziptools', 'public.certificate.x509.pem')
+	privateKey = os.path.join('ziptools', 'private.key.pk8')
+
+	# Unsigned->signed
+	proc = subprocess.run(['java', '-jar', zipsigner,
+		publicKey, privateKey, unsigned, 'tmp_signed.zip'])
+	if proc.returncode != 0:
+		error('First sign flashable zip failed!')
 
 	# Adjust zip
 	proc = subprocess.run([os.path.join('ziptools', 'zipadjust'), 'tmp_signed.zip', 'tmp_adjusted.zip'])
@@ -161,9 +183,8 @@ def sign_adjust_zip(unsigned, output):
 		error('Adjust flashable zip failed!')
 
 	# Adjusted -> output
-	proc = subprocess.run(['java', '-jar', os.path.join('ziptools', 'minsignapk.jar'),
-		os.path.join('ziptools', 'public.certificate.x509.pem'),
-		os.path.join('ziptools', 'private.key.pk8'), 'tmp_adjusted.zip', output])
+	proc = subprocess.run(['java', '-jar', zipsigner,
+		"-m", publicKey, privateKey, 'tmp_adjusted.zip', output])
 	if proc.returncode != 0:
 		error('Second sign flashable zip failed!')
 
diff --git a/ziptools/apksigner.jar b/ziptools/apksigner.jar
deleted file mode 100644
index b9017b06a..000000000
Binary files a/ziptools/apksigner.jar and /dev/null differ
diff --git a/ziptools/minsignapk.jar b/ziptools/minsignapk.jar
deleted file mode 100644
index cd38d23fa..000000000
Binary files a/ziptools/minsignapk.jar and /dev/null differ
diff --git a/ziptools/signapk.jar b/ziptools/signapk.jar
deleted file mode 100644
index 8435b757a..000000000
Binary files a/ziptools/signapk.jar and /dev/null differ
diff --git a/ziptools/src/MinSignAPK.java b/ziptools/src/MinSignAPK.java
deleted file mode 100644
index 78508175a..000000000
--- a/ziptools/src/MinSignAPK.java
+++ /dev/null
@@ -1,191 +0,0 @@
-/*
- * Copyright (C) 2008 The Android Open Source Project
- *
- * 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.
- */
-/* This is just a copy/paste/cut job from original SignAPK sources. This 
- * adaptation adds only the whole-file signature to a ZIP(jar,apk) file, and 
- * doesn't do any of the per-file signing, creating manifests, etc. This is 
- * useful when you've changed the structure itself of an existing (signed!) 
- * ZIP file, but the extracted contents are still identical. Using
- * the normal SignAPK may re-arrange other things inside the ZIP, which may
- * be unwanted behavior. This version only changes the ZIP's tail and keeps
- * the rest the same - CF
- */
-
-package eu.chainfire.minsignapk;
-
-import java.io.ByteArrayOutputStream;
-import java.io.DataInputStream;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.security.GeneralSecurityException;
-import java.security.KeyFactory;
-import java.security.PrivateKey;
-import java.security.Signature;
-import java.security.cert.CertificateFactory;
-import java.security.cert.X509Certificate;
-import java.security.spec.InvalidKeySpecException;
-import java.security.spec.KeySpec;
-import java.security.spec.PKCS8EncodedKeySpec;
-
-import sun.security.pkcs.ContentInfo;
-import sun.security.pkcs.PKCS7;
-import sun.security.pkcs.SignerInfo;
-import sun.security.x509.AlgorithmId;
-import sun.security.x509.X500Name;
-
-public class MinSignAPK {
-	/** Write a .RSA file with a digital signature. */
-    private static void writeSignatureBlock(Signature signature, X509Certificate publicKey, OutputStream out)
-            throws IOException, GeneralSecurityException {
-        SignerInfo signerInfo = new SignerInfo(new X500Name(publicKey.getIssuerX500Principal().getName()),
-                publicKey.getSerialNumber(), AlgorithmId.get("SHA1"), AlgorithmId.get("RSA"), signature.sign());
-
-        PKCS7 pkcs7 = new PKCS7(new AlgorithmId[] { AlgorithmId.get("SHA1") }, new ContentInfo(ContentInfo.DATA_OID,
-                null), new X509Certificate[] { publicKey }, new SignerInfo[] { signerInfo });
-
-        pkcs7.encodeSignedData(out);
-    }
-    
-	private static void signWholeOutputFile(byte[] zipData, OutputStream outputStream, X509Certificate publicKey,
-            PrivateKey privateKey) throws IOException, GeneralSecurityException {
-
-        // For a zip with no archive comment, the
-        // end-of-central-directory record will be 22 bytes long, so
-        // we expect to find the EOCD marker 22 bytes from the end.
-        if (zipData[zipData.length - 22] != 0x50 || zipData[zipData.length - 21] != 0x4b
-                || zipData[zipData.length - 20] != 0x05 || zipData[zipData.length - 19] != 0x06) {
-            throw new IllegalArgumentException("zip data already has an archive comment");
-        }
-
-        Signature signature = Signature.getInstance("SHA1withRSA");
-        signature.initSign(privateKey);
-        signature.update(zipData, 0, zipData.length - 2);
-
-        ByteArrayOutputStream temp = new ByteArrayOutputStream();
-
-        // put a readable message and a null char at the start of the
-        // archive comment, so that tools that display the comment
-        // (hopefully) show something sensible.
-        // TODO: anything more useful we can put in this message?
-        byte[] message = "signed by SignApk".getBytes("UTF-8");
-        temp.write(message);
-        temp.write(0);
-        writeSignatureBlock(signature, publicKey, temp);
-        int total_size = temp.size() + 6;
-        if (total_size > 0xffff) {
-            throw new IllegalArgumentException("signature is too big for ZIP file comment");
-        }
-        // signature starts this many bytes from the end of the file
-        int signature_start = total_size - message.length - 1;
-        temp.write(signature_start & 0xff);
-        temp.write((signature_start >> 8) & 0xff);
-        // Why the 0xff bytes? In a zip file with no archive comment,
-        // bytes [-6:-2] of the file are the little-endian offset from
-        // the start of the file to the central directory. So for the
-        // two high bytes to be 0xff 0xff, the archive would have to
-        // be nearly 4GB in side. So it's unlikely that a real
-        // commentless archive would have 0xffs here, and lets us tell
-        // an old signed archive from a new one.
-        temp.write(0xff);
-        temp.write(0xff);
-        temp.write(total_size & 0xff);
-        temp.write((total_size >> 8) & 0xff);
-        temp.flush();
-
-        // Signature verification checks that the EOCD header is the
-        // last such sequence in the file (to avoid minzip finding a
-        // fake EOCD appended after the signature in its scan). The
-        // odds of producing this sequence by chance are very low, but
-        // let's catch it here if it does.
-        byte[] b = temp.toByteArray();
-        for (int i = 0; i < b.length - 3; ++i) {
-            if (b[i] == 0x50 && b[i + 1] == 0x4b && b[i + 2] == 0x05 && b[i + 3] == 0x06) {
-                throw new IllegalArgumentException("found spurious EOCD header at " + i);
-            }
-        }
-
-        outputStream.write(zipData, 0, zipData.length - 2);
-        outputStream.write(total_size & 0xff);
-        outputStream.write((total_size >> 8) & 0xff);
-        temp.writeTo(outputStream);
-    }
-	
-	private static PrivateKey readPrivateKey(File file)
-	        throws IOException, GeneralSecurityException {
-		DataInputStream input = new DataInputStream(new FileInputStream(file));
-		try {
-			byte[] bytes = new byte[(int) file.length()];
-			input.read(bytes);
-
-			// dont support encrypted keys atm
-			//KeySpec spec = decryptPrivateKey(bytes, file);
-			//if (spec == null) {
-				KeySpec spec = new PKCS8EncodedKeySpec(bytes);
-			//}
-
-			try {
-				return KeyFactory.getInstance("RSA").generatePrivate(spec);
-			} catch (InvalidKeySpecException ex) {
-				return KeyFactory.getInstance("DSA").generatePrivate(spec);
-			}
-		} finally {
-			input.close();
-		}
-	}
-	
-	private static X509Certificate readPublicKey(File file)
-			throws IOException, GeneralSecurityException {
-		FileInputStream input = new FileInputStream(file);
-		try {
-			CertificateFactory cf = CertificateFactory.getInstance("X.509");
-			return (X509Certificate) cf.generateCertificate(input);
-		} finally {
-			input.close();
-		}
-	}	
-	
-	public static void main(String[] args) {
-		if (args.length < 4) {
-			System.out.println("MinSignAPK pemfile pk8file inzip outzip");
-			System.out.println("- only adds whole-file signature to zip");
-			return;
-		}
-		 
-		String pemFile = args[0];
-		String pk8File = args[1];
-		String inFile = args[2];
-		String outFile = args[3];
-		
-		try {
-			X509Certificate publicKey = readPublicKey(new File(pemFile));
-			PrivateKey privateKey = readPrivateKey(new File(pk8File));
-			
-			InputStream fis = new FileInputStream(inFile);
-			byte[] buffer = new byte[(int)(new File(inFile)).length()];
-			fis.read(buffer);
-			fis.close();
-			
-			OutputStream fos = new FileOutputStream(outFile, false);
-			signWholeOutputFile(buffer, fos, publicKey, privateKey);
-			fos.close();			
-		} catch (Exception e) {
-			e.printStackTrace();
-		}
-	 }
-}
diff --git a/ziptools/src/zipadjust.c b/ziptools/zipadjust_src/zipadjust.c
similarity index 100%
rename from ziptools/src/zipadjust.c
rename to ziptools/zipadjust_src/zipadjust.c
diff --git a/ziptools/src/zipadjust.h b/ziptools/zipadjust_src/zipadjust.h
similarity index 100%
rename from ziptools/src/zipadjust.h
rename to ziptools/zipadjust_src/zipadjust.h
diff --git a/ziptools/src/zipadjust_run.c b/ziptools/zipadjust_src/zipadjust_run.c
similarity index 100%
rename from ziptools/src/zipadjust_run.c
rename to ziptools/zipadjust_src/zipadjust_run.c
diff --git a/ziptools/zipsigner/.gitignore b/ziptools/zipsigner/.gitignore
new file mode 100644
index 000000000..87dc02017
--- /dev/null
+++ b/ziptools/zipsigner/.gitignore
@@ -0,0 +1,7 @@
+*.iml
+.gradle
+/local.properties
+.idea/
+/build
+*.hprof
+app/.externalNativeBuild/
diff --git a/ziptools/zipsigner/build.gradle b/ziptools/zipsigner/build.gradle
new file mode 100644
index 000000000..60879d23a
--- /dev/null
+++ b/ziptools/zipsigner/build.gradle
@@ -0,0 +1,36 @@
+group 'com.topjohnwu'
+version '1.0.0'
+
+apply plugin: 'java'
+apply plugin: 'com.github.johnrengelman.shadow'
+
+sourceCompatibility = 1.8
+
+jar {
+    manifest {
+        attributes 'Main-Class': 'com.topjohnwu.ZipSigner'
+    }
+}
+
+shadowJar {
+   classifier = null
+   version = null
+}
+
+buildscript {
+    repositories {
+        jcenter()
+    }
+    dependencies {
+        classpath 'com.github.jengelman.gradle.plugins:shadow:2.0.1'
+    }
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    compile 'org.bouncycastle:bcprov-jdk15on:1.57'
+    compile 'org.bouncycastle:bcpkix-jdk15on:1.57'
+}
diff --git a/ziptools/zipsigner/gradle/wrapper/gradle-wrapper.jar b/ziptools/zipsigner/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 000000000..ccfe89381
Binary files /dev/null and b/ziptools/zipsigner/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/ziptools/zipsigner/gradle/wrapper/gradle-wrapper.properties b/ziptools/zipsigner/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 000000000..1d882d3e6
--- /dev/null
+++ b/ziptools/zipsigner/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Thu Aug 24 10:35:40 CST 2017
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-3.5-rc-2-bin.zip
diff --git a/ziptools/zipsigner/gradlew b/ziptools/zipsigner/gradlew
new file mode 100755
index 000000000..4453ccea3
--- /dev/null
+++ b/ziptools/zipsigner/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn ( ) {
+    echo "$*"
+}
+
+die ( ) {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save ( ) {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/ziptools/zipsigner/gradlew.bat b/ziptools/zipsigner/gradlew.bat
new file mode 100644
index 000000000..f9553162f
--- /dev/null
+++ b/ziptools/zipsigner/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/ziptools/zipsigner/settings.gradle b/ziptools/zipsigner/settings.gradle
new file mode 100644
index 000000000..a42023557
--- /dev/null
+++ b/ziptools/zipsigner/settings.gradle
@@ -0,0 +1,4 @@
+rootProject.name = 'zipsigner'
+include 'apksigner'
+rootProject.name = 'zipsigner'
+
diff --git a/ziptools/zipsigner/src/main/java/com/topjohnwu/ZipSigner.java b/ziptools/zipsigner/src/main/java/com/topjohnwu/ZipSigner.java
new file mode 100644
index 000000000..bf7245314
--- /dev/null
+++ b/ziptools/zipsigner/src/main/java/com/topjohnwu/ZipSigner.java
@@ -0,0 +1,567 @@
+package com.topjohnwu;
+
+import org.bouncycastle.asn1.ASN1InputStream;
+import org.bouncycastle.asn1.ASN1ObjectIdentifier;
+import org.bouncycastle.asn1.DEROutputStream;
+import org.bouncycastle.asn1.cms.CMSObjectIdentifiers;
+import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
+import org.bouncycastle.cert.jcajce.JcaCertStore;
+import org.bouncycastle.cms.CMSException;
+import org.bouncycastle.cms.CMSProcessableByteArray;
+import org.bouncycastle.cms.CMSSignedData;
+import org.bouncycastle.cms.CMSSignedDataGenerator;
+import org.bouncycastle.cms.CMSTypedData;
+import org.bouncycastle.cms.jcajce.JcaSignerInfoGeneratorBuilder;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bouncycastle.operator.ContentSigner;
+import org.bouncycastle.operator.OperatorCreationException;
+import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
+import org.bouncycastle.operator.jcajce.JcaDigestCalculatorProviderBuilder;
+import org.bouncycastle.util.encoders.Base64;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.security.DigestOutputStream;
+import java.security.GeneralSecurityException;
+import java.security.KeyFactory;
+import java.security.MessageDigest;
+import java.security.PrivateKey;
+import java.security.Provider;
+import java.security.Security;
+import java.security.cert.CertificateEncodingException;
+import java.security.cert.CertificateFactory;
+import java.security.cert.X509Certificate;
+import java.security.spec.PKCS8EncodedKeySpec;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.Locale;
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.jar.Attributes;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.jar.JarOutputStream;
+import java.util.jar.Manifest;
+import java.util.regex.Pattern;
+
+/*
+* Modified from from AOSP(Marshmallow) SignAPK.java
+* */
+
+public class ZipSigner {
+    private static final String CERT_SF_NAME = "META-INF/CERT.SF";
+    private static final String CERT_SIG_NAME = "META-INF/CERT.%s";
+
+    private static Provider sBouncyCastleProvider;
+
+    // bitmasks for which hash algorithms we need the manifest to include.
+    private static final int USE_SHA1 = 1;
+    private static final int USE_SHA256 = 2;
+
+    /**
+     * Return one of USE_SHA1 or USE_SHA256 according to the signature
+     * algorithm specified in the cert.
+     */
+    private static int getDigestAlgorithm(X509Certificate cert) {
+        String sigAlg = cert.getSigAlgName().toUpperCase(Locale.US);
+        if ("SHA1WITHRSA".equals(sigAlg) ||
+                "MD5WITHRSA".equals(sigAlg)) {     // see "HISTORICAL NOTE" above.
+            return USE_SHA1;
+        } else if (sigAlg.startsWith("SHA256WITH")) {
+            return USE_SHA256;
+        } else {
+            throw new IllegalArgumentException("unsupported signature algorithm \"" + sigAlg +
+                    "\" in cert [" + cert.getSubjectDN());
+        }
+    }
+    /** Returns the expected signature algorithm for this key type. */
+    private static String getSignatureAlgorithm(X509Certificate cert) {
+        String sigAlg = cert.getSigAlgName().toUpperCase(Locale.US);
+        String keyType = cert.getPublicKey().getAlgorithm().toUpperCase(Locale.US);
+        if ("RSA".equalsIgnoreCase(keyType)) {
+            if (getDigestAlgorithm(cert) == USE_SHA256) {
+                return "SHA256withRSA";
+            } else {
+                return "SHA1withRSA";
+            }
+        } else if ("EC".equalsIgnoreCase(keyType)) {
+            return "SHA256withECDSA";
+        } else {
+            throw new IllegalArgumentException("unsupported key type: " + keyType);
+        }
+    }
+    // Files matching this pattern are not copied to the output.
+    private static Pattern stripPattern =
+            Pattern.compile("^(META-INF/((.*)[.](SF|RSA|DSA|EC)|com/android/otacert))|(" +
+                    Pattern.quote(JarFile.MANIFEST_NAME) + ")$");
+    private static X509Certificate readPublicKey(InputStream input)
+            throws IOException, GeneralSecurityException {
+        try {
+            CertificateFactory cf = CertificateFactory.getInstance("X.509");
+            return (X509Certificate) cf.generateCertificate(input);
+        } finally {
+            input.close();
+        }
+    }
+
+    /** Read a PKCS#8 format private key. */
+    private static PrivateKey readPrivateKey(InputStream input)
+            throws IOException, GeneralSecurityException {
+        try {
+            byte[] buffer = new byte[4096];
+            int size = input.read(buffer);
+            byte[] bytes = Arrays.copyOf(buffer, size);
+            /* Check to see if this is in an EncryptedPrivateKeyInfo structure. */
+            PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(bytes);
+            /*
+             * Now it's in a PKCS#8 PrivateKeyInfo structure. Read its Algorithm
+             * OID and use that to construct a KeyFactory.
+             */
+            ASN1InputStream bIn = new ASN1InputStream(new ByteArrayInputStream(spec.getEncoded()));
+            PrivateKeyInfo pki = PrivateKeyInfo.getInstance(bIn.readObject());
+            String algOid = pki.getPrivateKeyAlgorithm().getAlgorithm().getId();
+            return KeyFactory.getInstance(algOid).generatePrivate(spec);
+        } finally {
+            input.close();
+        }
+    }
+    /**
+     * Add the hash(es) of every file to the manifest, creating it if
+     * necessary.
+     */
+    private static Manifest addDigestsToManifest(JarFile jar, int hashes)
+            throws IOException, GeneralSecurityException {
+        Manifest input = jar.getManifest();
+        Manifest output = new Manifest();
+        Attributes main = output.getMainAttributes();
+        if (input != null) {
+            main.putAll(input.getMainAttributes());
+        } else {
+            main.putValue("Manifest-Version", "1.0");
+            main.putValue("Created-By", "1.0 (Android SignApk)");
+        }
+        MessageDigest md_sha1 = null;
+        MessageDigest md_sha256 = null;
+        if ((hashes & USE_SHA1) != 0) {
+            md_sha1 = MessageDigest.getInstance("SHA1");
+        }
+        if ((hashes & USE_SHA256) != 0) {
+            md_sha256 = MessageDigest.getInstance("SHA256");
+        }
+        byte[] buffer = new byte[4096];
+        int num;
+        // We sort the input entries by name, and add them to the
+        // output manifest in sorted order.  We expect that the output
+        // map will be deterministic.
+        TreeMap<String, JarEntry> byName = new TreeMap<String, JarEntry>();
+        for (Enumeration<JarEntry> e = jar.entries(); e.hasMoreElements(); ) {
+            JarEntry entry = e.nextElement();
+            byName.put(entry.getName(), entry);
+        }
+        for (JarEntry entry: byName.values()) {
+            String name = entry.getName();
+            if (!entry.isDirectory() &&
+                    (stripPattern == null || !stripPattern.matcher(name).matches())) {
+                InputStream data = jar.getInputStream(entry);
+                while ((num = data.read(buffer)) > 0) {
+                    if (md_sha1 != null) md_sha1.update(buffer, 0, num);
+                    if (md_sha256 != null) md_sha256.update(buffer, 0, num);
+                }
+                Attributes attr = null;
+                if (input != null) attr = input.getAttributes(name);
+                attr = attr != null ? new Attributes(attr) : new Attributes();
+                if (md_sha1 != null) {
+                    attr.putValue("SHA1-Digest",
+                            new String(Base64.encode(md_sha1.digest()), "ASCII"));
+                }
+                if (md_sha256 != null) {
+                    attr.putValue("SHA-256-Digest",
+                            new String(Base64.encode(md_sha256.digest()), "ASCII"));
+                }
+                output.getEntries().put(name, attr);
+            }
+        }
+        return output;
+    }
+
+    /** Write to another stream and track how many bytes have been
+     *  written.
+     */
+    private static class CountOutputStream extends FilterOutputStream {
+        private int mCount;
+        public CountOutputStream(OutputStream out) {
+            super(out);
+            mCount = 0;
+        }
+        @Override
+        public void write(int b) throws IOException {
+            super.write(b);
+            mCount++;
+        }
+        @Override
+        public void write(byte[] b, int off, int len) throws IOException {
+            super.write(b, off, len);
+            mCount += len;
+        }
+        public int size() {
+            return mCount;
+        }
+    }
+    /** Write a .SF file with a digest of the specified manifest. */
+    private static void writeSignatureFile(Manifest manifest, OutputStream out,
+                                           int hash)
+            throws IOException, GeneralSecurityException {
+        Manifest sf = new Manifest();
+        Attributes main = sf.getMainAttributes();
+        main.putValue("Signature-Version", "1.0");
+        main.putValue("Created-By", "1.0 (Android SignApk)");
+        MessageDigest md = MessageDigest.getInstance(
+                hash == USE_SHA256 ? "SHA256" : "SHA1");
+        PrintStream print = new PrintStream(
+                new DigestOutputStream(new ByteArrayOutputStream(), md),
+                true, "UTF-8");
+        // Digest of the entire manifest
+        manifest.write(print);
+        print.flush();
+        main.putValue(hash == USE_SHA256 ? "SHA-256-Digest-Manifest" : "SHA1-Digest-Manifest",
+                new String(Base64.encode(md.digest()), "ASCII"));
+        Map<String, Attributes> entries = manifest.getEntries();
+        for (Map.Entry<String, Attributes> entry : entries.entrySet()) {
+            // Digest of the manifest stanza for this entry.
+            print.print("Name: " + entry.getKey() + "\r\n");
+            for (Map.Entry<Object, Object> att : entry.getValue().entrySet()) {
+                print.print(att.getKey() + ": " + att.getValue() + "\r\n");
+            }
+            print.print("\r\n");
+            print.flush();
+            Attributes sfAttr = new Attributes();
+            sfAttr.putValue(hash == USE_SHA256 ? "SHA-256-Digest" : "SHA1-Digest-Manifest",
+                    new String(Base64.encode(md.digest()), "ASCII"));
+            sf.getEntries().put(entry.getKey(), sfAttr);
+        }
+        CountOutputStream cout = new CountOutputStream(out);
+        sf.write(cout);
+        // A bug in the java.util.jar implementation of Android platforms
+        // up to version 1.6 will cause a spurious IOException to be thrown
+        // if the length of the signature file is a multiple of 1024 bytes.
+        // As a workaround, add an extra CRLF in this case.
+        if ((cout.size() % 1024) == 0) {
+            cout.write('\r');
+            cout.write('\n');
+        }
+    }
+    /** Sign data and write the digital signature to 'out'. */
+    private static void writeSignatureBlock(
+            CMSTypedData data, X509Certificate publicKey, PrivateKey privateKey,
+            OutputStream out)
+            throws IOException,
+            CertificateEncodingException,
+            OperatorCreationException,
+            CMSException {
+        ArrayList<X509Certificate> certList = new ArrayList<>(1);
+        certList.add(publicKey);
+        JcaCertStore certs = new JcaCertStore(certList);
+        CMSSignedDataGenerator gen = new CMSSignedDataGenerator();
+        ContentSigner signer = new JcaContentSignerBuilder(getSignatureAlgorithm(publicKey))
+                .setProvider(sBouncyCastleProvider)
+                .build(privateKey);
+        gen.addSignerInfoGenerator(
+                new JcaSignerInfoGeneratorBuilder(
+                        new JcaDigestCalculatorProviderBuilder()
+                                .setProvider(sBouncyCastleProvider)
+                                .build())
+                        .setDirectSignature(true)
+                        .build(signer, publicKey));
+        gen.addCertificates(certs);
+        CMSSignedData sigData = gen.generate(data, false);
+        ASN1InputStream asn1 = new ASN1InputStream(sigData.getEncoded());
+        DEROutputStream dos = new DEROutputStream(out);
+        dos.writeObject(asn1.readObject());
+    }
+    /**
+     * Copy all the files in a manifest from input to output.  We set
+     * the modification times in the output to a fixed time, so as to
+     * reduce variation in the output file and make incremental OTAs
+     * more efficient.
+     */
+    private static void copyFiles(Manifest manifest, JarFile in, JarOutputStream out,
+                                  long timestamp, int alignment) throws IOException {
+        byte[] buffer = new byte[4096];
+        int num;
+        Map<String, Attributes> entries = manifest.getEntries();
+        ArrayList<String> names = new ArrayList<String>(entries.keySet());
+        Collections.sort(names);
+        boolean firstEntry = true;
+        long offset = 0L;
+        // We do the copy in two passes -- first copying all the
+        // entries that are STORED, then copying all the entries that
+        // have any other compression flag (which in practice means
+        // DEFLATED).  This groups all the stored entries together at
+        // the start of the file and makes it easier to do alignment
+        // on them (since only stored entries are aligned).
+        for (String name : names) {
+            JarEntry inEntry = in.getJarEntry(name);
+            JarEntry outEntry = null;
+            if (inEntry.getMethod() != JarEntry.STORED) continue;
+            // Preserve the STORED method of the input entry.
+            outEntry = new JarEntry(inEntry);
+            outEntry.setTime(timestamp);
+            // 'offset' is the offset into the file at which we expect
+            // the file data to begin.  This is the value we need to
+            // make a multiple of 'alignement'.
+            offset += JarFile.LOCHDR + outEntry.getName().length();
+            if (firstEntry) {
+                // The first entry in a jar file has an extra field of
+                // four bytes that you can't get rid of; any extra
+                // data you specify in the JarEntry is appended to
+                // these forced four bytes.  This is JAR_MAGIC in
+                // JarOutputStream; the bytes are 0xfeca0000.
+                offset += 4;
+                firstEntry = false;
+            }
+            if (alignment > 0 && (offset % alignment != 0)) {
+                // Set the "extra data" of the entry to between 1 and
+                // alignment-1 bytes, to make the file data begin at
+                // an aligned offset.
+                int needed = alignment - (int)(offset % alignment);
+                outEntry.setExtra(new byte[needed]);
+                offset += needed;
+            }
+            out.putNextEntry(outEntry);
+            InputStream data = in.getInputStream(inEntry);
+            while ((num = data.read(buffer)) > 0) {
+                out.write(buffer, 0, num);
+                offset += num;
+            }
+            out.flush();
+        }
+        // Copy all the non-STORED entries.  We don't attempt to
+        // maintain the 'offset' variable past this point; we don't do
+        // alignment on these entries.
+        for (String name : names) {
+            JarEntry inEntry = in.getJarEntry(name);
+            JarEntry outEntry = null;
+            if (inEntry.getMethod() == JarEntry.STORED) continue;
+            // Create a new entry so that the compressed len is recomputed.
+            outEntry = new JarEntry(name);
+            outEntry.setTime(timestamp);
+            out.putNextEntry(outEntry);
+            InputStream data = in.getInputStream(inEntry);
+            while ((num = data.read(buffer)) > 0) {
+                out.write(buffer, 0, num);
+            }
+            out.flush();
+        }
+    }
+
+    // This class is to provide a file's content, but trimming out the last two bytes
+    // Used for signWholeFile
+    private static class CMSProcessableFile implements CMSTypedData {
+
+        private File file;
+        private ASN1ObjectIdentifier type;
+        private byte[] buffer;
+        int bufferSize = 0;
+
+        CMSProcessableFile(File file) {
+            this.file = file;
+            type = new ASN1ObjectIdentifier(CMSObjectIdentifiers.data.getId());
+            buffer = new byte[4096];
+        }
+
+        @Override
+        public ASN1ObjectIdentifier getContentType() {
+            return type;
+        }
+
+        @Override
+        public void write(OutputStream out) throws IOException, CMSException {
+            FileInputStream input = new FileInputStream(file);
+            long len = file.length() - 2;
+            while ((bufferSize = input.read(buffer)) > 0) {
+                if (len <= bufferSize) {
+                    out.write(buffer, 0, (int) len);
+                    break;
+                } else {
+                    out.write(buffer, 0, bufferSize);
+                }
+                len -= bufferSize;
+            }
+        }
+
+        @Override
+        public Object getContent() {
+            return file;
+        }
+
+        byte[] getTail() {
+            return Arrays.copyOfRange(buffer, 0, bufferSize);
+        }
+    }
+
+    private static void signWholeFile(File input, X509Certificate publicKey,
+                                      PrivateKey privateKey, OutputStream outputStream)
+            throws Exception {
+        ByteArrayOutputStream temp = new ByteArrayOutputStream();
+        // put a readable message and a null char at the start of the
+        // archive comment, so that tools that display the comment
+        // (hopefully) show something sensible.
+        // TODO: anything more useful we can put in this message?
+        byte[] message = "signed by SignApk".getBytes("UTF-8");
+        temp.write(message);
+        temp.write(0);
+
+        CMSProcessableFile cmsFile = new CMSProcessableFile(input);
+        writeSignatureBlock(cmsFile, publicKey, privateKey, temp);
+
+        // For a zip with no archive comment, the
+        // end-of-central-directory record will be 22 bytes long, so
+        // we expect to find the EOCD marker 22 bytes from the end.
+        byte[] zipData = cmsFile.getTail();
+        if (zipData[zipData.length-22] != 0x50 ||
+                zipData[zipData.length-21] != 0x4b ||
+                zipData[zipData.length-20] != 0x05 ||
+                zipData[zipData.length-19] != 0x06) {
+            throw new IllegalArgumentException("zip data already has an archive comment");
+        }
+        int total_size = temp.size() + 6;
+        if (total_size > 0xffff) {
+            throw new IllegalArgumentException("signature is too big for ZIP file comment");
+        }
+        // signature starts this many bytes from the end of the file
+        int signature_start = total_size - message.length - 1;
+        temp.write(signature_start & 0xff);
+        temp.write((signature_start >> 8) & 0xff);
+        // Why the 0xff bytes?  In a zip file with no archive comment,
+        // bytes [-6:-2] of the file are the little-endian offset from
+        // the start of the file to the central directory.  So for the
+        // two high bytes to be 0xff 0xff, the archive would have to
+        // be nearly 4GB in size.  So it's unlikely that a real
+        // commentless archive would have 0xffs here, and lets us tell
+        // an old signed archive from a new one.
+        temp.write(0xff);
+        temp.write(0xff);
+        temp.write(total_size & 0xff);
+        temp.write((total_size >> 8) & 0xff);
+        temp.flush();
+        // Signature verification checks that the EOCD header is the
+        // last such sequence in the file (to avoid minzip finding a
+        // fake EOCD appended after the signature in its scan).  The
+        // odds of producing this sequence by chance are very low, but
+        // let's catch it here if it does.
+        byte[] b = temp.toByteArray();
+        for (int i = 0; i < b.length-3; ++i) {
+            if (b[i] == 0x50 && b[i+1] == 0x4b && b[i+2] == 0x05 && b[i+3] == 0x06) {
+                throw new IllegalArgumentException("found spurious EOCD header at " + i);
+            }
+        }
+        cmsFile.write(outputStream);
+        outputStream.write(total_size & 0xff);
+        outputStream.write((total_size >> 8) & 0xff);
+        temp.writeTo(outputStream);
+    }
+    private static void signFile(Manifest manifest, JarFile inputJar,
+                                 X509Certificate publicKey, PrivateKey privateKey,
+                                 JarOutputStream outputJar)
+            throws Exception {
+        // Assume the certificate is valid for at least an hour.
+        long timestamp = publicKey.getNotBefore().getTime() + 3600L * 1000;
+        // MANIFEST.MF
+        JarEntry je = new JarEntry(JarFile.MANIFEST_NAME);
+        je.setTime(timestamp);
+        outputJar.putNextEntry(je);
+        manifest.write(outputJar);
+        je = new JarEntry(CERT_SF_NAME);
+        je.setTime(timestamp);
+        outputJar.putNextEntry(je);
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        writeSignatureFile(manifest, baos, getDigestAlgorithm(publicKey));
+        byte[] signedData = baos.toByteArray();
+        outputJar.write(signedData);
+        // CERT.{EC,RSA} / CERT#.{EC,RSA}
+        final String keyType = publicKey.getPublicKey().getAlgorithm();
+        je = new JarEntry(String.format(CERT_SIG_NAME, keyType));
+        je.setTime(timestamp);
+        outputJar.putNextEntry(je);
+        writeSignatureBlock(new CMSProcessableByteArray(signedData),
+                publicKey, privateKey, outputJar);
+    }
+
+    public static void main(String[] args) {
+        boolean minSign = false;
+        int argStart = 0;
+
+        if (args.length < 4) {
+            System.err.println("Usage: zipsigner [-m] publickey.x509[.pem] privatekey.pk8 input.jar output.jar");
+            System.exit(2);
+        }
+
+        if (args[0].equals("-m")) {
+            minSign = true;
+            argStart = 1;
+        }
+
+        sBouncyCastleProvider = new BouncyCastleProvider();
+        Security.insertProviderAt(sBouncyCastleProvider, 1);
+
+        File pubKey = new File(args[argStart]);
+        File privKey = new File(args[argStart + 1]);
+        File input = new File(args[argStart + 2]);
+        File output = new File(args[argStart + 3]);
+
+        int alignment = 4;
+        JarFile inputJar = null;
+        FileOutputStream outputFile = null;
+        int hashes = 0;
+        try {
+            X509Certificate publicKey = readPublicKey(new FileInputStream(pubKey));
+            hashes |= getDigestAlgorithm(publicKey);
+
+            // Set the ZIP file timestamp to the starting valid time
+            // of the 0th certificate plus one hour (to match what
+            // we've historically done).
+            long timestamp = publicKey.getNotBefore().getTime() + 3600L * 1000;
+            PrivateKey privateKey = readPrivateKey(new FileInputStream(privKey));
+
+            outputFile = new FileOutputStream(output);
+            if (minSign) {
+                ZipSigner.signWholeFile(input, publicKey, privateKey, outputFile);
+            } else {
+                inputJar = new JarFile(input, false);  // Don't verify.
+                JarOutputStream outputJar = new JarOutputStream(outputFile);
+                // For signing .apks, use the maximum compression to make
+                // them as small as possible (since they live forever on
+                // the system partition).  For OTA packages, use the
+                // default compression level, which is much much faster
+                // and produces output that is only a tiny bit larger
+                // (~0.1% on full OTA packages I tested).
+                outputJar.setLevel(9);
+                Manifest manifest = addDigestsToManifest(inputJar, hashes);
+                copyFiles(manifest, inputJar, outputJar, timestamp, alignment);
+                signFile(manifest, inputJar, publicKey, privateKey, outputJar);
+                outputJar.close();
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+            System.exit(1);
+        } finally {
+            try {
+                if (inputJar != null) inputJar.close();
+                if (outputFile != null) outputFile.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+                System.exit(1);
+            }
+        }
+    }
+}
\ No newline at end of file