Magisk/ziptools/src/MinSignAPK.java
2016-12-06 02:45:51 +08:00

192 lines
7.5 KiB
Java

/*
* 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();
}
}
}