Calculate offset for unhide

This commit is contained in:
topjohnwu 2017-09-03 23:00:54 +08:00
parent 926c7359a2
commit 3424395e10

View File

@ -68,11 +68,14 @@ public class ZipUtils {
// File name in assets
private static final String PUBLIC_KEY_NAME = "public.certificate.x509.pem";
private static final String PRIVATE_KEY_NAME = "private.key.pk8";
private static final String UNHIDE_NAME = "unhide.apk";
private static final String UNHIDE_APK = "unhide.apk";
private static final String CERT_SF_NAME = "META-INF/CERT.SF";
private static final String CERT_SIG_NAME = "META-INF/CERT.%s";
private static final String ANDROID_MANIFEST = "AndroidManifest.xml";
private static final byte[] UNHIDE_PKG_NAME = "com.topjohnwu.unhide\0".getBytes();
private static Provider sBouncyCastleProvider;
// bitmasks for which hash algorithms we need the manifest to include.
private static final int USE_SHA1 = 1;
@ -90,22 +93,42 @@ public class ZipUtils {
File temp = new File(context.getCacheDir(), "temp.apk");
String pkg = "";
try {
JarInputStream source = new JarInputStream(context.getAssets().open(UNHIDE_NAME));
JarInputStream source = new JarInputStream(context.getAssets().open(UNHIDE_APK));
JarOutputStream dest = new JarOutputStream(new FileOutputStream(temp));
JarEntry entry;
int size;
byte buffer[] = new byte[4096];
while ((entry = source.getNextJarEntry()) != null) {
dest.putNextEntry(new JarEntry(entry.getName()));
if (TextUtils.equals(entry.getName(), "AndroidManifest.xml")) {
if (TextUtils.equals(entry.getName(), ANDROID_MANIFEST)) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
while((size = source.read(buffer)) != -1) {
baos.write(buffer, 0, size);
}
int offset = -1;
byte xml[] = baos.toByteArray();
pkg = Utils.genPackageName("com.", 20);
for (int i = 0; i < 20; ++i) {
xml[424 + i] = (byte) pkg.charAt(i);
// Linear search pattern offset
for (int i = 0; i < xml.length - UNHIDE_PKG_NAME.length; ++i) {
boolean match = true;
for (int j = 0; j < UNHIDE_PKG_NAME.length; ++j) {
if (xml[i + j] != UNHIDE_PKG_NAME[j]) {
match = false;
break;
}
}
if (match) {
offset = i;
break;
}
}
if (offset < 0)
return "";
// Patch binary XML with new package name
pkg = Utils.genPackageName("com.", UNHIDE_PKG_NAME.length - 1);
for (int i = 0; i < pkg.length(); ++i) {
xml[offset + i] = (byte) pkg.charAt(i);
}
dest.write(xml);
} else {