/*
* 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.
*/
package com.android.signapk;
import sun.misc.BASE64Encoder;
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;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
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.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.security.AlgorithmParameters;
import java.security.DigestOutputStream;
import java.security.GeneralSecurityException;
import java.security.Key;
import java.security.KeyFactory;
import java.security.MessageDigest;
import java.security.PrivateKey;
import java.security.Signature;
import java.security.SignatureException;
import java.security.cert.Certificate;
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 java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.Enumeration;
import java.util.List;
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 javax.crypto.Cipher;
import javax.crypto.EncryptedPrivateKeyInfo;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
/**
* Command line tool to sign JAR files (including APKs and OTA updates) in
* a way compatible with the mincrypt verifier, using SHA1 and RSA keys.
*/
class SignApk {
private static final String CERT_SF_NAME = "META-INF/CERT.SF";
private static final String CERT_RSA_NAME = "META-INF/CERT.RSA";
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();
}
}
/**
* Reads the password from stdin and returns it as a string.
*
* @param keyFile The file containing the private key. Used to prompt the user.
*/
private static String readPassword(File keyFile) {
// TODO: use Console.readPassword() when it's available.
System.out.print("Enter password for " + keyFile + " (password will not be hidden): ");
System.out.flush();
BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
try {
return stdin.readLine();
} catch (IOException ex) {
return null;
}
}
/**
* Decrypt an encrypted PKCS 8 format private key.
*
* Based on ghstark's post on Aug 6, 2006 at
* http://forums.sun.com/thread.jspa?threadID=758133&messageID=4330949
*
* @param encryptedPrivateKey The raw data of the private key
* @param keyFile The file containing the private key
*/
private static KeySpec decryptPrivateKey(byte[] encryptedPrivateKey, File keyFile)
throws GeneralSecurityException {
EncryptedPrivateKeyInfo epkInfo;
try {
epkInfo = new EncryptedPrivateKeyInfo(encryptedPrivateKey);
} catch (IOException ex) {
// Probably not an encrypted key.
return null;
}
char[] password = readPassword(keyFile).toCharArray();
SecretKeyFactory skFactory = SecretKeyFactory.getInstance(epkInfo.getAlgName());
Key key = skFactory.generateSecret(new PBEKeySpec(password));
Cipher cipher = Cipher.getInstance(epkInfo.getAlgName());
cipher.init(Cipher.DECRYPT_MODE, key, epkInfo.getAlgParameters());
try {
return epkInfo.getKeySpec(cipher);
} catch (InvalidKeySpecException ex) {
System.err.println("signapk: Password for " + keyFile + " may be bad.");
throw ex;
}
}
/** Read a PKCS 8 format private key. */
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);
KeySpec spec = decryptPrivateKey(bytes, file);
if (spec == null) {
spec = new PKCS8EncodedKeySpec(bytes);
}
try {
return KeyFactory.getInstance("RSA").generatePrivate(spec);
} catch (InvalidKeySpecException ex) {
return KeyFactory.getInstance("DSA").generatePrivate(spec);
}
} finally {
input.close();
}
}
/** Add the SHA1 of every file to the manifest, creating it if necessary. */
private static Manifest addDigestsToManifest(JarFile jar)
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)");
}
BASE64Encoder base64 = new BASE64Encoder();
MessageDigest md = MessageDigest.getInstance("SHA1");
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() && !name.equals(JarFile.MANIFEST_NAME) &&
!name.equals(CERT_SF_NAME) && !name.equals(CERT_RSA_NAME)) {
InputStream data = jar.getInputStream(entry);
while ((num = data.read(buffer)) > 0) {
md.update(buffer, 0, num);
}
Attributes attr = null;
if (input != null) attr = input.getAttributes(name);
attr = attr != null ? new Attributes(attr) : new Attributes();
attr.putValue("SHA1-Digest", base64.encode(md.digest()));
output.getEntries().put(name, attr);
}
}
return output;
}
/** Write to another stream and also feed it to the Signature object. */
private static class SignatureOutputStream extends FilterOutputStream {
private Signature mSignature;
public SignatureOutputStream(OutputStream out, Signature sig) {
super(out);
mSignature = sig;
}
@Override
public void write(int b) throws IOException {
try {
mSignature.update((byte) b);
} catch (SignatureException e) {
throw new IOException("SignatureException: " + e);
}
super.write(b);
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
try {
mSignature.update(b, off, len);
} catch (SignatureException e) {
throw new IOException("SignatureException: " + e);
}
super.write(b, off, len);
}
}
/** Write a .SF file with a digest the specified manifest. */
private static void writeSignatureFile(Manifest manifest, OutputStream out)
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)");
BASE64Encoder base64 = new BASE64Encoder();
MessageDigest md = MessageDigest.getInstance("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("SHA1-Digest-Manifest", base64.encode(md.digest()));
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("SHA1-Digest", base64.encode(md.digest()));
sf.getEntries().put(entry.getKey(), sfAttr);
}
sf.write(out);
}
/** 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);
}
/** Copy all the files in a manifest from input to output. */
private static void copyFiles(Manifest manifest,
JarFile in, JarOutputStream out) throws IOException {
byte[] buffer = new byte[4096];
int num;
Map<String, Attributes> entries = manifest.getEntries();
List<String> names = new ArrayList(entries.keySet());
Collections.sort(names);
for (String name : names) {
JarEntry inEntry = in.getJarEntry(name);
if (inEntry.getMethod() == JarEntry.STORED) {
// Preserve the STORED method of the input entry.
out.putNextEntry(new JarEntry(inEntry));
} else {
// Create a new entry so that the compressed len is recomputed.
JarEntry je = new JarEntry(name);
je.setTime(inEntry.getTime());
out.putNextEntry(je);
}
InputStream data = in.getInputStream(inEntry);
while ((num = data.read(buffer)) > 0) {
out.write(buffer, 0, num);
}
out.flush();
}
}
public static void main(String[] args) {
if (args.length != 4) {
System.err.println("Usage: signapk " +
"publickey.x509[.pem] privatekey.pk8 " +
"input.jar output.jar");
System.exit(2);
}
JarFile inputJar = null;
JarOutputStream outputJar = null;
try {
X509Certificate publicKey = readPublicKey(new File(args[0]));
// Assume the certificate is valid for at least an hour.
long timestamp = publicKey.getNotBefore().getTime() + 3600L * 1000;
PrivateKey privateKey = readPrivateKey(new File(args[1]));
inputJar = new JarFile(new File(args[2]), false); // Don't verify.
outputJar = new JarOutputStream(new FileOutputStream(args[3]));
outputJar.setLevel(9);
JarEntry je;
// MANIFEST.MF
Manifest manifest = addDigestsToManifest(inputJar);
je = new JarEntry(JarFile.MANIFEST_NAME);
je.setTime(timestamp);
outputJar.putNextEntry(je);
manifest.write(outputJar);
// CERT.SF
Signature signature = Signature.getInstance("SHA1withRSA");
signature.initSign(privateKey);
je = new JarEntry(CERT_SF_NAME);
je.setTime(timestamp);
outputJar.putNextEntry(je);
writeSignatureFile(manifest,
new SignatureOutputStream(outputJar, signature));
// CERT.RSA
je = new JarEntry(CERT_RSA_NAME);
je.setTime(timestamp);
outputJar.putNextEntry(je);
writeSignatureBlock(signature, publicKey, outputJar);
// Everything else
copyFiles(manifest, inputJar, outputJar);
} catch (Exception e) {
e.printStackTrace();
System.exit(1);
} finally {
try {
if (inputJar != null) inputJar.close();
if (outputJar != null) outputJar.close();
} catch (IOException e) {
e.printStackTrace();
System.exit(1);
}
}
}
}
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