Example usage for org.objectweb.asm MethodVisitor visitVarInsn

List of usage examples for org.objectweb.asm MethodVisitor visitVarInsn

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Introduction

In this page you can find the example usage for org.objectweb.asm MethodVisitor visitVarInsn.

Prototype

public void visitVarInsn(final int opcode, final int var)

Source Link

Document

Visits a local variable instruction.

Usage

From source file:jtaint.StringAdapter.java

License:Apache License

/** Force the StringBuilder/StringBuffer constructors to convert to
 * a String and invoke the String constructor
 *//*from w w w . ja v  a  2  s .  co m*/
private void replaceConstructorStringBuilder(MethodVisitor mv, String name) {
    mv.visitCode();
    mv.visitVarInsn(ALOAD, 0);
    mv.visitVarInsn(ALOAD, 1);
    mv.visitMethodInsn(INVOKEVIRTUAL, name, "toString", "()Ljava/lang/String;");
    mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", "(Ljava/lang/String;)V");
    mv.visitInsn(RETURN);
    mv.visitMaxs(2, 2);
    mv.visitEnd();
}

From source file:jtaint.StringAdapter.java

License:Apache License

private void copyField(MethodVisitor mv, String name, String desc) {
    mv.visitVarInsn(ALOAD, 0);
    mv.visitVarInsn(ALOAD, 1);// w  w  w  .ja  v  a 2s  .c  o  m
    mv.visitFieldInsn(GETFIELD, className, name, desc);
    mv.visitFieldInsn(PUTFIELD, className, name, desc);
}

From source file:jtaint.StringAdapter.java

License:Apache License

/** Force the String constructor to just copy all fields */
private void replaceConstructorString(MethodVisitor mv) {
    mv.visitCode();//from w w  w  . j  ava  2  s .  c o  m
    mv.visitVarInsn(ALOAD, 0);
    mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");

    copyField(mv, "offset", "I");
    copyField(mv, "count", "I");
    copyField(mv, "value", "[C");
    copyField(mv, ByteCodeUtil.internalName("tainted"), "Z");

    mv.visitInsn(RETURN);
    mv.visitMaxs(2, 2);
    mv.visitEnd();
}

From source file:jtaint.StringAdapter.java

License:Apache License

/** Export package-private java.lang methods for use by jtaint helper 
 * functions. /*from w w  w.  j ava  2s  . c om*/
 */
private void buildExportWrapper(ClassVisitor cv, String exportOwner, String name, String desc) {
    MethodVisitor mv = cv.visitMethod(ACC_PUBLIC + ACC_STATIC, ByteCodeUtil.internalName(name), desc, null,
            null);
    mv.visitCode();
    Type[] t = Type.getArgumentTypes(desc);

    int l = 0;
    for (int i = 0; i < t.length; l += t[i].getSize(), i++)
        mv.visitVarInsn(t[i].getOpcode(ILOAD), l);
    mv.visitMethodInsn(INVOKESTATIC, exportOwner, name, desc);

    mv.visitInsn(Type.getReturnType(desc).getOpcode(IRETURN));
    mv.visitMaxs(l, l);
    mv.visitEnd();
}

From source file:jtaint.StringAdapter.java

License:Apache License

/** Create new method that compares its argument to the package-private
 * constant Character.ERROR. This must be exported for jtaint helper
 * methods. Equivalent to the following Java code:
 *
 * public static boolean isError(int c) {
 *     return c == Character.ERROR;//from   w  w  w.ja  va2s .  c  o m
 * }
 */
private void addIsErrorMethod(ClassVisitor cv) {
    boolean isError = false;
    MethodVisitor mv = cv.visitMethod(ACC_PUBLIC + ACC_STATIC, ByteCodeUtil.internalName("isError"), "(I)Z",
            null, null);
    mv.visitCode();
    mv.visitVarInsn(ILOAD, 0);

    /* Test to see if java/lang/Character uses ERROR or CHAR_ERROR 
     * If ERROR cannot be found, an getDeclaredFields throws an exception
     */
    try {
        Character.class.getDeclaredField("ERROR");
        isError = true;
    } catch (Throwable th) {
        /* ignore */ }

    if (isError)
        mv.visitFieldInsn(GETSTATIC, "java/lang/Character", "ERROR", "I");
    else
        mv.visitFieldInsn(GETSTATIC, "java/lang/Character", "CHAR_ERROR", "C");

    Label l = new Label();
    mv.visitJumpInsn(IF_ICMPEQ, l);
    mv.visitInsn(ICONST_0);
    mv.visitInsn(IRETURN);

    mv.visitLabel(l);
    if (version == V1_6)
        mv.visitFrame(F_SAME, 0, null, 0, null);

    mv.visitInsn(ICONST_1);
    mv.visitInsn(IRETURN);
    mv.visitMaxs(2, 1);
    mv.visitEnd();
}

From source file:jtaint.StringAdapter.java

License:Apache License

/** Create a new method that returns a Taint object representing the taint
 * for this String. Equivalent to the following Java code:
 * //from  w ww  .  ja va  2  s  . co m
 * public Taint taint() {
 *     if (!tainted) {
 *         return null;
 *     } else {
 *         return jtaint.StringUtil.stringToTaint(value, count);
 *     }
 * }
 */

private void addTaintMethod(ClassVisitor cv) {
    MethodVisitor mv = cv.visitMethod(ACC_PUBLIC, ByteCodeUtil.internalName("taint"), "()Ljtaint/Taint;", null,
            null);
    mv.visitCode();

    mv.visitVarInsn(ALOAD, 0);
    mv.visitFieldInsn(GETFIELD, className, ByteCodeUtil.internalName("tainted"), "Z");

    Label l = new Label();
    mv.visitJumpInsn(IFNE, l);
    mv.visitInsn(ACONST_NULL);
    mv.visitInsn(ARETURN);

    mv.visitLabel(l);
    if (version == V1_6)
        mv.visitFrame(F_SAME, 0, null, 0, null);

    mv.visitVarInsn(ALOAD, 0);
    mv.visitFieldInsn(GETFIELD, className, "value", "[C");
    mv.visitVarInsn(ALOAD, 0);
    mv.visitFieldInsn(GETFIELD, className, "count", "I");
    mv.visitMethodInsn(INVOKESTATIC, "jtaint/StringUtil", "stringToTaint", "([CI)Ljtaint/Taint;");
    mv.visitInsn(ARETURN);
    mv.visitMaxs(4, 1);
    mv.visitEnd();
}

From source file:jtaint.StringAdapter.java

License:Apache License

/** Add a new constructor to a create a (partially or fully) tainted 
 * String. Equivalent to the following Java code:
 *
 * public String(String original, Taint t) {
 *     super();/*from ww w . j  av a2s . com*/
 *     this.count = original.count;
 *
 *     if (!t.isTainted()) {
 *         this.offset = original.offset;
 *         this.value = original.value;
 *         this.tainted = original.tainted;
 *         return
 *     }
 *
 *     this.offset = 0;
 *     this.value = jtaint.StringUtil.taintToString(original, t)
 *     if (this.value.length == this.count)
 *         this.tainted = false;
 *     else
 *         this.tainted = true;
 *     return;
 * The final check (if value.length == count) is true only when an error
 * occurs during the execution of taintToString
 */

private void addConstructor(ClassVisitor cv) {
    MethodVisitor mv = cv.visitMethod(ACC_PUBLIC, "<init>", "(Ljava/lang/String;Ljtaint/Taint;)V", null, null);
    mv.visitCode();
    mv.visitVarInsn(ALOAD, 0);
    mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");

    copyField(mv, "count", "I");

    Label l0 = new Label();
    mv.visitVarInsn(ALOAD, 2);
    mv.visitMethodInsn(INVOKEVIRTUAL, "jtaint/Taint", "isTainted", "()Z");
    mv.visitJumpInsn(IFNE, l0);

    /* Taint object is actually untainted, copy all fields and return */
    copyField(mv, "offset", "I");
    copyField(mv, "value", "[C");
    copyField(mv, ByteCodeUtil.internalName("tainted"), "Z");
    mv.visitInsn(RETURN);

    mv.visitLabel(l0);
    if (version == V1_6)
        mv.visitFrame(F_SAME, 0, null, 0, null);
    mv.visitVarInsn(ALOAD, 0);
    mv.visitInsn(ICONST_0);
    mv.visitFieldInsn(PUTFIELD, className, "offset", "I");

    mv.visitVarInsn(ALOAD, 0);
    mv.visitVarInsn(ALOAD, 1);
    mv.visitVarInsn(ALOAD, 2);
    mv.visitMethodInsn(INVOKESTATIC, "jtaint/StringUtil", "taintToString",
            "(Ljava/lang/String;Ljtaint/Taint;)[C");
    mv.visitInsn(DUP_X1);
    mv.visitFieldInsn(PUTFIELD, className, "value", "[C");
    mv.visitInsn(ARRAYLENGTH);
    mv.visitVarInsn(ALOAD, 0);
    mv.visitFieldInsn(GETFIELD, className, "count", "I");

    Label l1 = new Label();
    mv.visitJumpInsn(IF_ICMPEQ, l1);
    mv.visitVarInsn(ALOAD, 0);
    mv.visitInsn(ICONST_1);
    mv.visitFieldInsn(PUTFIELD, className, ByteCodeUtil.internalName("tainted"), "Z");
    mv.visitInsn(RETURN);

    mv.visitLabel(l1);
    if (version == V1_6)
        mv.visitFrame(F_SAME, 0, null, 0, null);
    mv.visitVarInsn(ALOAD, 0);
    mv.visitInsn(ICONST_0);
    mv.visitFieldInsn(PUTFIELD, className, ByteCodeUtil.internalName("tainted"), "Z");

    mv.visitInsn(RETURN);

    mv.visitMaxs(3, 3);
    mv.visitEnd();
}

From source file:jtaint.StringMakerAdapter.java

License:Apache License

private void buildToStringWrapper(MethodVisitor mv) {
    mv.visitCode();/*from   w  w w  .j  av  a 2 s .co  m*/

    mv.visitVarInsn(ALOAD, 0);
    mv.visitFieldInsn(GETFIELD, className, "strings", "[Ljava/lang/String;");

    mv.visitVarInsn(ALOAD, 0);
    mv.visitFieldInsn(GETFIELD, className, "size", "I");

    mv.visitVarInsn(ALOAD, 0);
    mv.visitMethodInsn(INVOKEVIRTUAL, className, ByteCodeUtil.internalName("toString"), "()Ljava/lang/String;");
    mv.visitMethodInsn(INVOKESTATIC, "jtaint/StringUtil", "concat",
            "([Ljava/lang/String;ILjava/lang/String;)Ljava/lang/String;");
    mv.visitInsn(ARETURN);
    mv.visitMaxs(3, 1);
    mv.visitEnd();
}

From source file:jtaint.StubAdapter.java

License:Apache License

private void buildStub(MethodDecl m) {
    String name = m.name(), desc = m.type();
    int acc = m.access();
    Type[] args = Type.getArgumentTypes(desc);
    Type ret = Type.getReturnType(desc);

    /* We want any subclasses to visit the generated stub, so we invoke 
     * this.visitMethod() (which should be overridden by relevant
     * subclasses).//from ww w  . j av a2 s.c  o m
     */
    MethodVisitor mv = visitMethod(acc, name, desc, null, null);

    if (mv == null)
        return;

    mv.visitCode();

    int l = 1;
    mv.visitVarInsn(ALOAD, 0);

    for (int i = 0; i < args.length; l += args[i].getSize(), i++)
        mv.visitVarInsn(args[i].getOpcode(ILOAD), l);

    mv.visitMethodInsn(INVOKESPECIAL, superName, name, desc);
    mv.visitInsn(ret.getOpcode(IRETURN));

    mv.visitMaxs(Math.max(l, ret.getSize()), l);
    mv.visitEnd();
}

From source file:jtaint.XssAdapter.java

License:Apache License

private void buildGenericWrapper(final MethodVisitor mv, final String methodName, final String desc) {
    new XssLockBuilder(mv, version, className, methodName, desc) {
        public void onUnlocked() {
            mv.visitVarInsn(ALOAD, 0);
            mv.visitMethodInsn(INVOKEVIRTUAL, className, ByteCodeUtil.internalName("getHtmlValidator"),
                    "()Ljtaint/HtmlValidator;");

            Type[] t = Type.getArgumentTypes(methodDesc);
            for (int i = 0, l = 1; i < t.length; l += t[i].getSize(), i++)
                mv.visitVarInsn(t[i].getOpcode(ILOAD), l);

            mv.visitMethodInsn(INVOKEVIRTUAL, "jtaint/HtmlValidator", methodName,
                    Type.getMethodDescriptor(Type.VOID_TYPE, t));
        }/*from w w w.  j  a  v a  2 s  .  c om*/
    }.build();
}