Improve XML string matching code

This commit is contained in:
topjohnwu 2018-10-26 02:50:45 -04:00
parent 9954154ca2
commit 958d6377e3

View File

@ -17,25 +17,32 @@ import com.topjohnwu.superuser.io.SuFileOutputStream;
import com.topjohnwu.utils.JarMap;
import com.topjohnwu.utils.SignAPK;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.CharBuffer;
import java.security.SecureRandom;
import java.util.jar.JarEntry;
public class PatchAPK {
public static final String LOWERALPHA = "abcdefghijklmnopqrstuvwxyz";
public static final String UPPERALPHA = LOWERALPHA.toUpperCase();
public static final String ALPHA = LOWERALPHA + UPPERALPHA;
public static final String DIGITS = "0123456789";
public static final String ALPHANUM = ALPHA + DIGITS;
public static final String ALPHANUMDOTS = ALPHANUM + "............";
private static String genPackageName(String prefix, int length) {
StringBuilder builder = new StringBuilder(length);
builder.append(prefix);
length -= prefix.length();
SecureRandom random = new SecureRandom();
String base = "abcdefghijklmnopqrstuvwxyz";
String alpha = base + base.toUpperCase();
String full = alpha + "0123456789..........";
char next, prev = '\0';
char next, prev = '.';
for (int i = 0; i < length; ++i) {
if (prev == '.' || i == length - 1 || i == 0) {
next = alpha.charAt(random.nextInt(alpha.length()));
if (prev == '.' || i == length - 1) {
next = ALPHA.charAt(random.nextInt(ALPHA.length()));
} else {
next = full.charAt(random.nextInt(full.length()));
next = ALPHANUMDOTS.charAt(random.nextInt(ALPHANUMDOTS.length()));
}
builder.append(next);
prev = next;
@ -43,48 +50,30 @@ public class PatchAPK {
return builder.toString();
}
private static int findOffset(byte buf[], byte pattern[]) {
private static boolean findAndPatch(byte xml[], String a, String b) {
if (a.length() != b.length())
return false;
char[] from = a.toCharArray(), to = b.toCharArray();
CharBuffer buf = ByteBuffer.wrap(xml).order(ByteOrder.LITTLE_ENDIAN).asCharBuffer();
int offset = -1;
for (int i = 0; i < buf.length - pattern.length; ++i) {
for (int i = 0; i < buf.length() - from.length; ++i) {
boolean match = true;
for (int j = 0; j < pattern.length; ++j) {
if (buf[i + j] != pattern[j]) {
for (int j = 0; j < from.length; ++j) {
if (buf.get(i + j) != from[j]) {
match = false;
break;
}
}
if (match) {
// Make sure it is null terminated
if (match && buf.get(i + from.length) == '\0') {
offset = i;
break;
}
}
return offset;
}
/* It seems that AAPT sometimes generate another type of string format */
private static boolean fallbackPatch(byte xml[], String from, String to) {
byte[] target = new byte[from.length() * 2 + 2];
for (int i = 0; i < from.length(); ++i) {
target[i * 2] = (byte) from.charAt(i);
}
int offset = findOffset(xml, target);
if (offset < 0)
return false;
byte[] dest = new byte[target.length - 2];
for (int i = 0; i < to.length(); ++i) {
dest[i * 2] = (byte) to.charAt(i);
}
System.arraycopy(dest, 0, xml, offset, dest.length);
return true;
}
private static boolean findAndPatch(byte xml[], String from, String to) {
byte target[] = (from + '\0').getBytes();
int offset = findOffset(xml, target);
if (offset < 0)
return fallbackPatch(xml, from, to);
System.arraycopy(to.getBytes(), 0, xml, offset, to.length());
buf.position(offset);
buf.put(to);
return true;
}
@ -123,9 +112,8 @@ public class PatchAPK {
JarEntry je = apk.getJarEntry(Const.ANDROID_MANIFEST);
byte xml[] = apk.getRawData(je);
if (!findAndPatch(xml, from, to))
return false;
if (!findAndPatch(xml, from + ".provider", to + ".provider"))
if (!findAndPatch(xml, from, to) ||
!findAndPatch(xml, from + ".provider", to + ".provider"))
return false;
// Write in changes