使用ASM反编译Java bytecode得到其汇编码全部类

紧接前面几篇文章的介绍，当如果使用ASM以及JASMIN来联合改写Java class的binary时，我们发现如何将代码按照JASMIN的格式反编译过来显得至关重要，若能反编译成功，那么接下来的汇编改写以及使用JASMIN重新改写此类即可轻松完成，恰巧借助ASM可以轻松完成此过程，此2个open source project的具体下载地址可Google得到，也可从我前面的文章中找到。使用...

iteye_6429

194人浏览 · 2010-12-22 19:36:00

iteye_6429 · 2010-12-22 19:36:00 发布

使用ASM来反编译class是最合适莫过了，ASM能够支持最新的Java class file的格式，对于JVM指令集支持得非常好，而且效率很高，好了，废话少说，上代码吧：

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import java.io.PrintWriter;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.objectweb.asm.ClassAdapter;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.EmptyVisitor;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.AnnotationNode;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.FieldNode;
import org.objectweb.asm.tree.InnerClassNode;
import org.objectweb.asm.tree.LabelNode;
import org.objectweb.asm.tree.LocalVariableNode;
import org.objectweb.asm.tree.MemberNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.TryCatchBlockNode;
import org.objectweb.asm.util.AbstractVisitor;

/**
* decompile the specified class and get all of its assemble source code
*
* @authorJackxin
*
*/
public class JasminifierClassAdapter extends ClassAdapter {

/**
* The print writer to be used to print the class.
*/
protected PrintWriter pw;

/**
* The label names. This map associate String values to Label keys.
*/
protected final Map<Label, String> labelNames;

protected ClassNode classNode = null;

public JasminifierClassAdapter(final PrintWriter pw, final ClassVisitor cv) {
super(new ClassNode() {
public void visitEnd() {
if (cv != null) {
accept(cv);
}
}
});
this.pw = pw;
labelNames = new HashMap<Label, String>();
}

@SuppressWarnings("unchecked")
public void visitEnd() {
ClassNode cn = (ClassNode) cv;
this.classNode = cn;
//pw.print(".bytecode ");
//pw.print(cn.version & 0xFFFF);
//pw.print('.');
//pw.println(cn.version >>> 16);
println(".source ", cn.sourceFile);
pw.print(".class");
pw.print(access(cn.access));
pw.print(' ');
pw.println(cn.name);
if (cn.superName == null) { // TODO Jasmin bug workaround
println(".super ", "java/lang/Object");
} else {
println(".super ", cn.superName);
}
for (int i = 0; i < cn.interfaces.size(); ++i) {
println(".implements ", (String) cn.interfaces.get(i));
}
if (cn.signature != null)
println(".signature ", '"' + cn.signature + '"');
if (cn.outerClass != null) {
pw.print(".enclosing method ");
pw.print(cn.outerClass);
if (cn.outerMethod != null) {
pw.print('/');
pw.print(cn.outerMethod);
pw.println(cn.outerMethodDesc);
} else {
pw.println();
}
}
if ((cn.access & Opcodes.ACC_DEPRECATED) != 0) {
pw.println(".deprecated");
}
printAnnotations(cn);
println(".debug ", cn.sourceDebug == null ? null
: '"' + cn.sourceDebug + '"');

for (int i = 0; i < cn.innerClasses.size(); ++i) {
InnerClassNode in = (InnerClassNode) cn.innerClasses.get(i);
pw.print(".inner class");
pw.print(access(in.access));
if (in.innerName != null) {
pw.print(' ');
pw.print(in.innerName);
}
if (in.name != null) {
pw.print(" inner ");
pw.print(in.name);
}
if (in.outerName != null) {
pw.print(" outer ");
pw.print(in.outerName);
}
pw.println();
}

for (int i = 0; i < cn.fields.size(); ++i) {
FieldNode fn = (FieldNode) cn.fields.get(i);
boolean annotations = false;
if (fn.visibleAnnotations != null
&& fn.visibleAnnotations.size() > 0) {
annotations = true;
}
if (fn.invisibleAnnotations != null
&& fn.invisibleAnnotations.size() > 0) {
annotations = true;
}
boolean deprecated = (fn.access & Opcodes.ACC_DEPRECATED) != 0;
pw.print("/n.field");
pw.print(access(fn.access));
pw.print(" '");
pw.print(fn.name);
pw.print("' ");
pw.print(fn.desc);
if (fn.signature != null && (!deprecated && !annotations)) {
pw.print(" signature /"");
pw.print(fn.signature);
pw.print("/"");
}
if (fn.value instanceof String) {
StringBuffer buf = new StringBuffer();
AbstractVisitor.appendString(buf, (String) fn.value);
pw.print(" = ");
pw.print(buf.toString());
} else if (fn.value != null) {
pw.print(" = ");
print(fn.value);
pw.println();
}
pw.println();
if (fn.signature != null && (deprecated || annotations)) {
pw.print(".signature /"");
pw.print(fn.signature);
pw.println("/"");
}
if (deprecated) {
pw.println(".deprecated");
}
printAnnotations(fn);
if (deprecated || annotations) {
pw.println(".end field");
}
}

for (int i = 0; i < cn.methods.size(); ++i) {
MethodNode mn = (MethodNode) cn.methods.get(i);
pw.print("/n.method");
pw.print(access(mn.access));
pw.print(' ');
pw.print(mn.name);
pw.println(mn.desc);
if (mn.signature != null) {
pw.print(".signature /"");
pw.print(mn.signature);
pw.println("/"");
}
if (mn.annotationDefault != null) {
pw.println(".annotation default");
printAnnotationValue(mn.annotationDefault);
pw.println(".end annotation");
}
printAnnotations(mn);
if (mn.visibleParameterAnnotations != null) {
for (int j = 0; j < mn.visibleParameterAnnotations.length; ++j) {
List l = mn.visibleParameterAnnotations[j];
if (l != null) {
for (int k = 0; k < l.size(); ++k) {
printAnnotation((AnnotationNode) l.get(k), 1, j + 1);
}
}
}
}
if (mn.invisibleParameterAnnotations != null) {
for (int j = 0; j < mn.invisibleParameterAnnotations.length; ++j) {
List l = mn.invisibleParameterAnnotations[j];
if (l != null) {
for (int k = 0; k < l.size(); ++k) {
printAnnotation((AnnotationNode) l.get(k), 2, j + 1);
}
}
}
}
for (int j = 0; j < mn.exceptions.size(); ++j) {
println(".throws ", (String) mn.exceptions.get(j));
}
if ((mn.access & Opcodes.ACC_DEPRECATED) != 0) {
pw.println(".deprecated");
}
if (mn.instructions.size() > 0) {
labelNames.clear();
for (int j = 0; j < mn.tryCatchBlocks.size(); ++j) {
TryCatchBlockNode tcb = (TryCatchBlockNode) mn.tryCatchBlocks
.get(j);
pw.print(".catch ");
pw.print(tcb.type);
pw.print(" from ");
print(tcb.start);
pw.print(" to ");
print(tcb.end);
pw.print(" using ");
print(tcb.handler);
pw.println();
}
for (int j = 0; j < mn.instructions.size(); ++j) {
AbstractInsnNode in = mn.instructions.get(j);
in.accept(new EmptyVisitor() {

public void visitFrame(int type, int local,
Object[] locals, int stack, Object[] stacks) {
if (type != Opcodes.F_FULL && type != Opcodes.F_NEW) {
throw new RuntimeException(
"Compressed frames unsupported, use EXPAND_FRAMES option");
}
pw.println(".stack");
for (int i = 0; i < local; ++i) {
pw.print("locals ");
printFrameType(locals[i]);
pw.println();
}
for (int i = 0; i < stack; ++i) {
pw.print("stack ");
printFrameType(stacks[i]);
pw.println();
}
pw.println(".end stack");
}

public void visitInsn(int opcode) {
print(opcode);
pw.println();
}

public void visitIntInsn(int opcode, int operand) {
print(opcode);
if (opcode == Opcodes.NEWARRAY) {
switch (operand) {
case Opcodes.T_BOOLEAN:
pw.println(" boolean");
break;
case Opcodes.T_CHAR:
pw.println(" char");
break;
case Opcodes.T_FLOAT:
pw.println(" float");
break;
case Opcodes.T_DOUBLE:
pw.println(" double");
break;
case Opcodes.T_BYTE:
pw.println(" byte");
break;
case Opcodes.T_SHORT:
pw.println(" short");
break;
case Opcodes.T_INT:
pw.println(" int");
break;
case Opcodes.T_LONG:
default:
pw.println(" long");
break;
}
} else {
pw.print(' ');
pw.println(operand);
}
}

public void visitVarInsn(int opcode, int var) {
print(opcode);
pw.print(' ');
pw.println(var);
}

public void visitTypeInsn(int opcode, String type) {
print(opcode);
pw.print(' ');
pw.println(type);
}

public void visitFieldInsn(int opcode, String owner,
String name, String desc) {
print(opcode);
pw.print(' ');
pw.print(owner);
pw.print('/');
pw.print(name);
pw.print(' ');
pw.println(desc);
}

public void visitMethodInsn(int opcode, String owner,
String name, String desc) {
print(opcode);
pw.print(' ');
pw.print(owner);
pw.print('/');
pw.print(name);
pw.print(desc);
if (opcode == Opcodes.INVOKEINTERFACE) {
pw.print(' ');
pw
.print((Type
.getArgumentsAndReturnSizes(desc) >> 2) - 1);
}
pw.println();
}

public void visitJumpInsn(int opcode, Label label) {
print(opcode);
pw.print(' ');
print(label);
pw.println();
}

public void visitLabel(Label label) {
print(label);
pw.println(':');
}

public void visitLdcInsn(Object cst) {
pw.print("ldc ");
if (cst instanceof Type) {
pw.print(((Type) cst).getInternalName());
} else {
print(cst);
}
pw.println();
}

public void visitIincInsn(int var, int increment) {
pw.print("iinc ");
pw.print(var);
pw.print(' ');
pw.println(increment);
}

public void visitTableSwitchInsn(int min, int max,
Label dflt, Label[] labels) {
pw.print("tableswitch ");
pw.println(min);
for (int i = 0; i < labels.length; ++i) {
print(labels[i]);
pw.println();
}
pw.print("default : ");
print(dflt);
pw.println();
}

public void visitLookupSwitchInsn(Label dflt,
int[] keys, Label[] labels) {
if (keys.length == 0) {
pw.print("goto "); // TODO Jasmin bug
// workaround
print(dflt);
pw.println();
return;
}
pw.println("lookupswitch");
for (int i = 0; i < keys.length; ++i) {
pw.print(keys[i]);
pw.print(" : ");
print(labels[i]);
pw.println();
}
pw.print("default : ");
print(dflt);
pw.println();
}

public void visitMultiANewArrayInsn(String desc,
int dims) {
pw.print("multianewarray ");
pw.print(desc);
pw.print(' ');
pw.println(dims);
}

public void visitLineNumber(int line, Label start) {
pw.print(".line ");
pw.println(line);
}
});
}
for (int j = 0; j < mn.localVariables.size(); ++j) {
LocalVariableNode lv = (LocalVariableNode) mn.localVariables
.get(j);
pw.print(".var ");
pw.print(lv.index);
pw.print(" is '");
pw.print(lv.name);
pw.print("' ");
pw.print(lv.desc);
if (lv.signature != null) {
pw.print(" signature /"");
pw.print(lv.signature);
pw.print("/"");
}
pw.print(" from ");
print(lv.start);
pw.print(" to ");
print(lv.end);
pw.println();
}
println(".limit locals ", Integer.toString(mn.maxLocals));
println(".limit stack ", Integer.toString(mn.maxStack));
}
pw.println(".end method");
}
super.visitEnd();
}

protected void println(final String directive, final String arg) {
if (arg != null) {
pw.print(directive);
pw.println(arg);
}
}

protected String access(final int access) {
StringBuffer b = new StringBuffer();
if ((access & Opcodes.ACC_PUBLIC) != 0) {
b.append(" public");
}
if ((access & Opcodes.ACC_PRIVATE) != 0) {
b.append(" private");
}
if ((access & Opcodes.ACC_PROTECTED) != 0) {
b.append(" protected");
}
if ((access & Opcodes.ACC_STATIC) != 0) {
b.append(" static");
}
if ((access & Opcodes.ACC_FINAL) != 0) {
b.append(" final");
}
if ((access & Opcodes.ACC_SYNCHRONIZED) != 0) {
b.append(" synchronized");
}
if ((access & Opcodes.ACC_VOLATILE) != 0) {
b.append(" volatile");
}
if ((access & Opcodes.ACC_TRANSIENT) != 0) {
b.append(" transient");
}
if ((access & Opcodes.ACC_NATIVE) != 0) {
b.append(" native");
}
if ((access & Opcodes.ACC_ABSTRACT) != 0) {
b.append(" abstract");
}
if ((access & Opcodes.ACC_STRICT) != 0) {
b.append(" fpstrict");
}
if ((access & Opcodes.ACC_SYNTHETIC) != 0) {
b.append(" synthetic");
}
if ((access & Opcodes.ACC_INTERFACE) != 0) {
b.append(" interface");
}
if ((access & Opcodes.ACC_ANNOTATION) != 0) {
b.append(" annotation");
}
if ((access & Opcodes.ACC_ENUM) != 0) {
b.append(" enum");
}
return b.toString();
}

protected void print(final int opcode) {
pw.print(AbstractVisitor.OPCODES[opcode].toLowerCase());
}

protected void print(final Object cst) {
if (cst instanceof String) {
StringBuffer buf = new StringBuffer();
AbstractVisitor.appendString(buf, (String) cst);
pw.print(buf.toString());
} else if (cst instanceof Float) {
Float f = (Float) cst;
if (f.isNaN() || f.isInfinite()) {
pw.print("0.0"); // TODO Jasmin bug workaround
} else {
pw.print(f);
}
} else if (cst instanceof Double) {
Double d = (Double) cst;
if (d.isNaN() || d.isInfinite()) {
pw.print("0.0"); // TODO Jasmin bug workaround
} else {
pw.print(d);
}
} else {
pw.print(cst);
}
}

protected void print(final Label l) {
String name = (String) labelNames.get(l);
if (name == null) {
name = "L" + labelNames.size();
labelNames.put(l, name);
}
pw.print(name);
}

protected void print(final LabelNode l) {
print(l.getLabel());
}

protected void printAnnotations(final MemberNode n) {
if (n.visibleAnnotations != null) {
for (int j = 0; j < n.visibleAnnotations.size(); ++j) {
printAnnotation((AnnotationNode) n.visibleAnnotations.get(j),
1, -1);
}
}
if (n.invisibleAnnotations != null) {
for (int j = 0; j < n.invisibleAnnotations.size(); ++j) {
printAnnotation((AnnotationNode) n.invisibleAnnotations.get(j),
2, -1);
}
}
}

protected void printAnnotation(final AnnotationNode n, final int visible,
final int param) {
pw.print(".annotation ");
if (visible > 0) {
if (param == -1) {
pw.print(visible == 1 ? "visible " : "invisible ");
} else {
pw.print(visible == 1 ? "visibleparam " : "invisibleparam ");
pw.print(param);
pw.print(' ');
}
pw.print(n.desc);
}
pw.println();
if (n.values != null) {
for (int i = 0; i < n.values.size(); i += 2) {
pw.print(n.values.get(i));
pw.print(' ');
printAnnotationValue(n.values.get(i + 1));
}
}
pw.println(".end annotation");
}

@SuppressWarnings("unchecked")
protected void printAnnotationValue(final Object value) {
if (value instanceof String[]) {
pw.print("e ");
pw.print(((String[]) value)[0]);
pw.print(" = ");
print(((String[]) value)[1]);
pw.println();
} else if (value instanceof AnnotationNode) {
pw.print("@ ");
pw.print(((AnnotationNode) value).desc);
pw.print(" = ");
printAnnotation((AnnotationNode) value, 0, -1);
} else if (value instanceof byte[]) {
pw.print("[B = ");
byte[] v = (byte[]) value;
for (int i = 0; i < v.length; i++) {
pw.print(v[i]);
pw.print(' ');
}
pw.println();
} else if (value instanceof boolean[]) {
pw.print("[Z = ");
boolean[] v = (boolean[]) value;
for (int i = 0; i < v.length; i++) {
pw.print(v[i] ? '1' : '0');
pw.print(' ');
}
pw.println();
} else if (value instanceof short[]) {
pw.print("[S = ");
short[] v = (short[]) value;
for (int i = 0; i < v.length; i++) {
pw.print(v[i]);
pw.print(' ');
}
pw.println();
} else if (value instanceof char[]) {
pw.print("[C = ");
char[] v = (char[]) value;
for (int i = 0; i < v.length; i++) {
pw.print(new Integer(v[i]));
pw.print(' ');
}
pw.println();
} else if (value instanceof int[]) {
pw.print("[I = ");
int[] v = (int[]) value;
for (int i = 0; i < v.length; i++) {
pw.print(v[i]);
pw.print(' ');
}
pw.println();
} else if (value instanceof long[]) {
pw.print("[J = ");
long[] v = (long[]) value;
for (int i = 0; i < v.length; i++) {
pw.print(v[i]);
pw.print(' ');
}
pw.println();
} else if (value instanceof float[]) {
pw.print("[F = ");
float[] v = (float[]) value;
for (int i = 0; i < v.length; i++) {
print(new Float(v[i]));
pw.print(' ');
}
pw.println();
} else if (value instanceof double[]) {
pw.print("[D = ");
double[] v = (double[]) value;
for (int i = 0; i < v.length; i++) {
print(new Double(v[i]));
pw.print(' ');
}
pw.println();
} else if (value instanceof List) {
List l = (List) value;
if (l.size() > 0) {
Object o = l.get(0);
if (o instanceof String[]) {
pw.print("[e ");
pw.print(((String[]) o)[0]);
pw.print(" = ");
} else if (o instanceof AnnotationNode) {
pw.print("[& ");
pw.print(((AnnotationNode) o).desc);
pw.print(" = ");
pw.print("[@ = ");
} else if (o instanceof String) {
pw.print("[s = ");
} else if (o instanceof Byte) {
pw.print("[B = ");
} else if (o instanceof Boolean) {
pw.print("[Z = ");
} else if (o instanceof Character) {
pw.print("[C = ");
} else if (o instanceof Short) {
pw.print("[S = ");
} else if (o instanceof Type) {
pw.print("[c = ");
} else if (o instanceof Integer) {
pw.print("[I = ");
} else if (o instanceof Float) {
pw.print("[F = ");
} else if (o instanceof Long) {
pw.print("[J = ");
} else if (o instanceof Double) {
pw.print("[D = ");
}
for (int j = 0; j < l.size(); ++j) {
printAnnotationArrayValue(l.get(j));
pw.print(' ');
}
} else {
pw.print("; empty array annotation value");
}
pw.println();
} else if (value instanceof String) {
pw.print("s = ");
print(value);
pw.println();
} else if (value instanceof Byte) {
pw.print("B = ");
pw.println(((Byte) value).intValue());
} else if (value instanceof Boolean) {
pw.print("Z = ");
pw.println(((Boolean) value).booleanValue() ? 1 : 0);
} else if (value instanceof Character) {
pw.print("C = ");
pw.println(new Integer(((Character) value).charValue()));
} else if (value instanceof Short) {
pw.print("S = ");
pw.println(((Short) value).intValue());
} else if (value instanceof Type) {
pw.print("c = ");
pw.println(((Type) value).getDescriptor());
} else if (value instanceof Integer) {
pw.print("I = ");
print(value);
pw.println();
} else if (value instanceof Float) {
pw.print("F = ");
print(value);
pw.println();
} else if (value instanceof Long) {
pw.print("J = ");
print(value);
pw.println();
} else if (value instanceof Double) {
pw.print("D = ");
print(value);
pw.println();
} else {
throw new RuntimeException();
}
}

protected void printAnnotationArrayValue(final Object value) {
if (value instanceof String[]) {
print(((String[]) value)[1]);
} else if (value instanceof AnnotationNode) {
printAnnotation((AnnotationNode) value, 0, -1);
} else if (value instanceof String) {
print(value);
} else if (value instanceof Byte) {
pw.print(((Byte) value).intValue());
} else if (value instanceof Boolean) {
pw.print(((Boolean) value).booleanValue() ? 1 : 0);
} else if (value instanceof Character) {
pw.print(new Integer(((Character) value).charValue()));
} else if (value instanceof Short) {
pw.print(((Short) value).intValue());
} else if (value instanceof Type) {
pw.print(((Type) value).getDescriptor());
} else {
print(value);
}
}

protected void printFrameType(final Object type) {
if (type == Opcodes.TOP) {
pw.print("Top");
} else if (type == Opcodes.INTEGER) {
pw.print("Integer");
} else if (type == Opcodes.FLOAT) {
pw.print("Float");
} else if (type == Opcodes.LONG) {
pw.print("Long");
} else if (type == Opcodes.DOUBLE) {
pw.print("Double");
} else if (type == Opcodes.NULL) {
pw.print("Null");
} else if (type == Opcodes.UNINITIALIZED_THIS) {
pw.print("UninitializedThis");
} else if (type instanceof Label) {
pw.print("Uninitialized ");
print((Label) type);
} else {
pw.print("Object ");
pw.print(type);
}
}

}

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调用函数代码如下:

public void disassembleJasminCode(String binaryFile, String sourceFile) throws IOException {
ClassReader cr = null;
FileInputStream fis = null;

if (binaryFile.endsWith(".class") || binaryFile.indexOf('//') > -1 || binaryFile.indexOf('/') > -1) {
fis = new FileInputStream(binaryFile);
cr = new ClassReader(fis);
} else {
cr = new ClassReader(binaryFile);
}

try {
FileOutputStream fos = new FileOutputStream(new File(sourceFile));
// if we want the binary file contains debug information, we need to skip setting the ClassReader.SKIP_DEBUG
JasminifierClassAdapter ca = new JasminifierClassAdapter(new PrintWriter(fos, true), null);
cr.accept(ca, ClassReader.SKIP_DEBUG | ClassReader.EXPAND_FRAMES);
fos.close();
} catch (IOException ioe) {
throw ioe;
} finally {
if (fis != null) {
fis.close();
}
}
}