Anti-disassemble tricks with illegal opcodes totally break JADX decompilation

[enovella]

This protector destroys all the JADX decompilation. It may be interesting to take a peek at how this protector confuses DEX decompilers by adding junk opcodes.

APK: https://koodous.com/apks/a5722d6ab8a2de93f94901129f9793a4b898a31fe33250e2466d4d877af1dcd3

More info:
rednaga/APKiD#52
JesusFreke/smali#562 (comment)

APKiD output:

$ apkid /tmp/GODDESS_KISS_v1.040.12_apkpure.com.apk 
[+] APKiD 1.0.0 :: from RedNaga :: rednaga.io
[*] /tmp/GODDESS_KISS_v1.040.12_apkpure.com.apk!classes.dex
 |-> anti_vm : Build.FINGERPRINT check, Build.MANUFACTURER check, Build.MODEL check, Build.PRODUCT check, Build.TAGS check, network operator name check, subscriber ID check
 |-> compiler : dexlib 2.x
 |-> protector : CNProtect (anti-disassemble)

[enovella]

Any workaround on this topic?

[manizzle]

JesusFreke/smali#562 (comment) looks like a way smali deals with it?

[zhangmengfeigithub]

mistake

[skylot]

I made incorrect instructions removing in branch issue-224. In most cases this is enough, for others I need to implement proper instructions checking and dead code elimination. This is not hard but need to change a lot of code.
Also I don't see any correct and usable code in these classes (correct me if I wrong), so I think these classes can be just ignored.
Another problem: if I enable this 'remove bad instructions' behavior by default it will hide jadx internal errors and you will see incorrect code instead error :(

P.S. Did anyone trying to use simplify or dex-oracle on this apk?

[enovella]

Hi all,

@manizzle:

Basically, uses the concept of dead code which is bad (from Dex Education presentation) to insert bad opcodes/junk.
Baksmali handles this correctly by ignoring the class.

You suggest to skip the class decompilation too?

@skylot:
Are you saying that these classes are intentionally included as a bait and they are pointless? If so, can I see the decompilation of any of them?
I do understand that it might not be smart to add this specific behaviour and affect thousands of normal cases.
I didnt try Simplify, but will do. I'll come back to you with more insight.

Cheers

[enovella]

I see the other branch issue-224, I will test it.

[enovella]

Testing the branch issue-224 and seems that the decompilation doesn't break as before. However, method signatures which should return java.lang.String are returning nothing.

package com.igaworks;

/* compiled from: pLcuvtHYMV33kSB2Tg4Q5xibvvXNoLrd8MvLCSa8VytUtHJHtMTRwRCb1xvlJds1CnSsqtO7LUEeQyrYWAUDx4VdLVgBP3M0w7ngpQwTKxUqSyQBSIah3pJXHo3H1QUuSabqGJAhfuMKW8HcjaQEm4CwqwEx3XkDeVsyU45m5R5UgTj324DO */
public class bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG {
    public int gCB9HY1RwJamUM0tn5Sbe3RwD0lVgxDl7tptnar9HhV1jAs8yiBtuVPPZKXETFD9OQGDKazAz4mFlKwVWl2XxvipjhgfqXJIzsC3mXchDXyCBwZBhpBE5h6Z1P9p8iQRlLKji6PHlYJPzAqJmiSc6t103Qpoy2wFFrkgFE2cSJFNTU8SRRw6() {
        return;
    }

    public String yAY9Vzgw8nofaAWHMNgoZMGykBxEc8AUp86q1FjzX42OlCCLGl0fq1ZtvzKgwRavy34NJRy8IztuhpBecxCPAKSI0gzsAIb7M6bXW5AN1HBnposh5Y1jddBqjEbhSHdNuQHNECNJEsvYyUoJYjlJofN8yfWQMntW6yMESf3QnIMBRtsUg8Qv() {
    }
}

Previous decompilation looked like this:

package com.igaworks;

/* compiled from: pLcuvtHYMV33kSB2Tg4Q5xibvvXNoLrd8MvLCSa8VytUtHJHtMTRwRCb1xvlJds1CnSsqtO7LUEeQyrYWAUDx4VdLVgBP3M0w7ngpQwTKxUqSyQBSIah3pJXHo3H1QUuSabqGJAhfuMKW8HcjaQEm4CwqwEx3XkDeVsyU45m5R5UgTj324DO */
public class bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG {
    public int gCB9HY1RwJamUM0tn5Sbe3RwD0lVgxDl7tptnar9HhV1jAs8yiBtuVPPZKXETFD9OQGDKazAz4mFlKwVWl2XxvipjhgfqXJIzsC3mXchDXyCBwZBhpBE5h6Z1P9p8iQRlLKji6PHlYJPzAqJmiSc6t103Qpoy2wFFrkgFE2cSJFNTU8SRRw6() {
        /* JADX: method processing error */
/*
Error: jadx.core.utils.exceptions.DecodeException: Load method exception: bogus opcode: 0079 in method: com.igaworks.bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG.gCB9HY1RwJamUM0tn5Sbe3RwD0lVgxDl7tptnar9HhV1jAs8yiBtuVPPZKXETFD9OQGDKazAz4mFlKwVWl2XxvipjhgfqXJIzsC3mXchDXyCBwZBhpBE5h6Z1P9p8iQRlLKji6PHlYJPzAqJmiSc6t103Qpoy2wFFrkgFE2cSJFNTU8SRRw6():int, dex: classes.dex
	at jadx.core.dex.nodes.MethodNode.load(MethodNode.java:116)
	at jadx.core.dex.nodes.ClassNode.load(ClassNode.java:249)
	at jadx.core.ProcessClass.process(ProcessClass.java:31)
	at jadx.api.JadxDecompiler.processClass(JadxDecompiler.java:282)
	at jadx.api.JavaClass.decompile(JavaClass.java:62)
	at jadx.api.JavaClass.getCode(JavaClass.java:48)
Caused by: java.lang.IllegalArgumentException: bogus opcode: 0079
	at com.android.dx.io.OpcodeInfo.get(OpcodeInfo.java:1217)
	at com.android.dx.io.OpcodeInfo.getName(OpcodeInfo.java:1224)
	at jadx.core.dex.instructions.InsnDecoder.decode(InsnDecoder.java:590)
	at jadx.core.dex.instructions.InsnDecoder.process(InsnDecoder.java:74)
	at jadx.core.dex.nodes.MethodNode.load(MethodNode.java:102)
	... 5 more
*/
        /*
        // Can't load method instructions.
        */
        throw new UnsupportedOperationException("Method not decompiled: com.igaworks.bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG.gCB9HY1RwJamUM0tn5Sbe3RwD0lVgxDl7tptnar9HhV1jAs8yiBtuVPPZKXETFD9OQGDKazAz4mFlKwVWl2XxvipjhgfqXJIzsC3mXchDXyCBwZBhpBE5h6Z1P9p8iQRlLKji6PHlYJPzAqJmiSc6t103Qpoy2wFFrkgFE2cSJFNTU8SRRw6():int");
    }

    public java.lang.String yAY9Vzgw8nofaAWHMNgoZMGykBxEc8AUp86q1FjzX42OlCCLGl0fq1ZtvzKgwRavy34NJRy8IztuhpBecxCPAKSI0gzsAIb7M6bXW5AN1HBnposh5Y1jddBqjEbhSHdNuQHNECNJEsvYyUoJYjlJofN8yfWQMntW6yMESf3QnIMBRtsUg8Qv() {
        /* JADX: method processing error */
/*
Error: jadx.core.utils.exceptions.DecodeException: Load method exception: index:38211, length=33787 in method: com.igaworks.bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG.yAY9Vzgw8nofaAWHMNgoZMGykBxEc8AUp86q1FjzX42OlCCLGl0fq1ZtvzKgwRavy34NJRy8IztuhpBecxCPAKSI0gzsAIb7M6bXW5AN1HBnposh5Y1jddBqjEbhSHdNuQHNECNJEsvYyUoJYjlJofN8yfWQMntW6yMESf3QnIMBRtsUg8Qv():java.lang.String, dex: classes.dex
	at jadx.core.dex.nodes.MethodNode.load(MethodNode.java:116)
	at jadx.core.dex.nodes.ClassNode.load(ClassNode.java:249)
	at jadx.core.ProcessClass.process(ProcessClass.java:31)
	at jadx.api.JadxDecompiler.processClass(JadxDecompiler.java:282)
	at jadx.api.JavaClass.decompile(JavaClass.java:62)
	at jadx.api.JavaClass.getCode(JavaClass.java:48)
Caused by: java.lang.IndexOutOfBoundsException: index:38211, length=33787
	at com.android.dex.Dex.checkBounds(Dex.java:147)
	at com.android.dex.Dex.access$1100(Dex.java:52)
	at com.android.dex.Dex$FieldIdTable.get(Dex.java:758)
	at com.android.dex.Dex$FieldIdTable.get(Dex.java:756)
	at jadx.core.dex.nodes.DexNode.getFieldId(DexNode.java:172)
	at jadx.core.dex.info.FieldInfo.fromDex(FieldInfo.java:29)
	at jadx.core.dex.instructions.InsnDecoder.decode(InsnDecoder.java:488)
	at jadx.core.dex.instructions.InsnDecoder.process(InsnDecoder.java:74)
	at jadx.core.dex.nodes.MethodNode.load(MethodNode.java:102)
	... 5 more
*/
        /*
        // Can't load method instructions.
        */
        throw new UnsupportedOperationException("Method not decompiled: com.igaworks.bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG.yAY9Vzgw8nofaAWHMNgoZMGykBxEc8AUp86q1FjzX42OlCCLGl0fq1ZtvzKgwRavy34NJRy8IztuhpBecxCPAKSI0gzsAIb7M6bXW5AN1HBnposh5Y1jddBqjEbhSHdNuQHNECNJEsvYyUoJYjlJofN8yfWQMntW6yMESf3QnIMBRtsUg8Qv():java.lang.String");
    }
}

This is indeed odd and I should reverse engineer the app to understand what's happening under the hood. For instance, there is an asset file that looks like packed code (libData.so).

I do not know if these changes can be merged within the master branch without altering the behaviour of other stuff. If not, let's leave this extreme case out for the moment.

[enovella]

Looking at little bit deeper with Radare2 and I observe many nops over the Dalvik bytecode:

$ r2 apk://cnprotector.apk
[0x0016c654]> ic~e8RD41S7WxJNiT3P6Ak5ogOzUXT1tkq
0x0016c654 [0x007f0734 - 0x007f07a2] (sz 110) class 7658 Lcom/igaworks/bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG super: Ljava/lang/Object;
0x007f0734 method 0 pC   Lcom/igaworks/bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG.method.<init>()V
0x007f074c method 1 p    Lcom/igaworks/bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG.method.gCB9HY1RwJamUM0tn5Sbe3RwD0lVgxDl7tptnar9HhV1jAs8yiBtuVPPZKXETFD9OQGDKazAz4mFlKwVWl2XxvipjhgfqXJIzsC3mXchDXyCBwZBhpBE5h6Z1P9p8iQRlLKji6PHlYJPzAqJmiSc6t103Qpoy2wFFrkgFE2cSJFNTU8SRRw6()I
0x007f0780 method 2 p    Lcom/igaworks/bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG.method.yAY9Vzgw8nofaAWHMNgoZMGykBxEc8AUp86q1FjzX42OlCCLGl0fq1ZtvzKgwRavy34NJRy8IztuhpBecxCPAKSI0gzsAIb7M6bXW5AN1HBnposh5Y1jddBqjEbhSHdNuQHNECNJEsvYyUoJYjlJofN8yfWQMntW6yMESf3QnIMBRtsUg8Qv()Ljava/lang/String;

[0x0016c654]> s 0x007f0780

[0x007f0780]> pd
            ;-- Lcom/igaworks/bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG.method.yAY9Vzgw8nofaAWHMNgoZMGykBxEc8AUp86q1FjzX42OlCCLGl0fq1ZtvzKgwRavy34NJRy8IztuhpBecxCPAKSI0gzsAIb7M6bXW5AN1HBnposh5Y1jddBqjEbhSHdNuQHNECNJEsvYyUoJYjlJofN8yfWQMntW6yMESf3QnIMBRtsUg8Qv()Ljava/lang/String;:
            ;-- method.public.Lcom_igaworks_bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG.Lcom_igaworks_bryGPqeke8RD41S7WxJNiT3P6Ak5ogOz:
            0x007f0780      008e           nop                         ; pLcuvtHYMV33kSB2Tg4Q5xibvvXNoLrd8MvLCSa8VytUtHJHtMTRwRCb1xvlJds1CnSsqtO7LUEeQyrYWAUDx4VdLVgBP3M0w7ngpQwTKxUqSyQBSIah3pJXHo3H1QUuSabqGJAhfuMKW8HcjaQEm4CwqwEx3XkDeVsyU45m5R5UgTj324DO.java:12
            0x007f0782      671b4395       sput v27, field+38211
            0x007f0786      6a9f9352       sput-boolean v159, Lcom/google/android/gms/internal/zzhj$zza;->zzKa Ljava/lang/String;
            0x007f078a      993d1b49       shr-int v61, v27, v73
            0x007f078e      8465           long-to-int v5, v6
            0x007f0790      1a0d439b       const-string v13, str.getCharSequenceExtra ; 0x3469d1
            0x007f0794      1b553a4a1f8d   const-string/jumbo v85, string+977936269 ; 0xfffffffb ; 5
            0x007f079a      453f0b1c       aget-wide v63, v11, v28
            0x007f079e      0f1f           return v31
            0x007f07a0      0d4e           move-exception v78
            0x007f07a2      0000           nop
            0x007f07a4      0100           move v0, v0
            0x007f07a6      0100           move v0, v0
            0x007f07a8      0100           move v0, v0
            0x007f07aa      0000           nop
            0x007f07ac      de744c00       or-int/lit8 v116, v76, 0
            0x007f07b0      0400           move-wide v0, v0
            0x007f07b2      0000           nop
            ;-- method.public.constructor.Lcom_igaworks_commerce_8s0GKjIChkfZn1BdgQLARyp04PVw1hmIzy88oCYXhkWNPaeNBGoP6sQQJFsPzLHfFwBIxt2DzpRKws83tXyy2JJhYqTtbPqoetPJBqLFI5JM0Is6LXT3L9uhOfA28A6UaU96SsHUZk3IlnpeqqEA7cZEhGdAtIh5PvHVFNOVKXF6r5C1xF1z.Lcom_igaworks_commerce_8s:
            0x007f07b4      70100cf50000   invoke-direct {v0}, Ljava/lang/Object.<init>()V ; 0xf50c ; I24trZx2VpS7TB8VEr26dBXNJQQFnJrV7sGf8KtC6OoTSiqGbdPmMkqYDorAiMM10gExKkeqUDqH3ARQq8Q83hr03YYbowqppA171Xl3XDcScV1FXeckaUobUWse2NGegaBb1xgxSIZrygiu80bPUXO29wdIKghuJLsrQFvvFagpQZsUZR9I.java:3
            0x007f07ba      0e00           return-void
            0x007f07bc      02000100       move/from16 v0, v1
            0x007f07c0      0000           nop
            0x007f07c2      0000           nop
            0x007f07c4      e3744c00       +iget-volatile v4, v7, Landroid/content/pm/ServiceInfo;->permission Ljava/lang/String;
            0x007f07c8      1100           return-object v0
            0x007f07ca      0000           nop
            0x007f07cc      0072           nop                         ; I24trZx2VpS7TB8VEr26dBXNJQQFnJrV7sGf8KtC6OoTSiqGbdPmMkqYDorAiMM10gExKkeqUDqH3ARQq8Q83hr03YYbowqppA171Xl3XDcScV1FXeckaUobUWse2NGegaBb1xgxSIZrygiu80bPUXO29wdIKghuJLsrQFvvFagpQZsUZR9I.java:12
            0x007f07ce      43c7           invalid
            0x007f07d0      55808180       iget-boolean v0, v8, Lcom/nhn/android/naverlogin/ui/OAuthLoginImage;->drawableByteStringNaverIconSeq02 Ljava/lang/String;
            0x007f07d4      4d475148       aput-object v71, v81, v72
            0x007f07d8      1b8f91bd8884   const-string/jumbo v143, string+-1849849724 ; 0xfffffff8 ; 8
            0x007f07de      30ab1b60       cmpg-double v171, v27, v96
            0x007f07e2      587f2ab2       iget-short v15, v7, field+45610
        ,=< 0x007f07e6      2803           goto 0x007f07ec
        |   0x007f07e8      b72b           xor-int/2addr v11, v2
        |   0x007f07ea      a170c352       or-long v112, v195, v82
            0x007f07ee      0000           nop
            0x007f07f0      02000100       move/from16 v0, v1
            0x007f07f4      0000           nop
            0x007f07f6      0000           nop
            0x007f07f8      e8744c00       +iget-wide-volatile v4, v7, Landroid/content/pm/ServiceInfo;->permission Ljava/lang/String;
            0x007f07fc      1100           return-object v0
            0x007f07fe      0000           nop
            ;-- Lcom/igaworks/commerce/8s0GKjIChkfZn1BdgQLARyp04PVw1hmIzy88oCYXhkWNPaeNBGoP6sQQJFsPzLHfFwBIxt2DzpRKws83tXyy2JJhYqTtbPqoetPJBqLFI5JM0Is6LXT3L9uhOfA28A6UaU96SsHUZk3IlnpeqqEA7cZEhGdAtIh5PvHVFNOVKXF6r5C1xF1z.method.wdrcFKmZpIONnH2Ps2ZdR6IZN1zppmgTRmrK0MIFxTuqwZpIUuoBSTT1KPzYMVT6ZAEyhOlxYUmO8xQAMDbs1UpEaD5dlYujVWQpNBnpKqCcNqke9IKaXm76mc2qzSq2iGa4gCkmc32bRQLcRRGImtNelQuUTvv4AfvhRbzmYP9WQ8q2vGv5()I:
            ;-- method.public.Lcom_igaworks_commerce_8s0GKjIChkfZn1BdgQLARyp04PVw1hmIzy88oCYXhkWNPaeNBGoP6sQQJFsPzLHfFwBIxt2DzpRKws83tXyy2JJhYqTtbPqoetPJBqLFI5JM0Is6LXT3L9uhOfA28A6UaU96SsHUZk3IlnpeqqEA7cZEhGdAtIh5PvHVFNOVKXF6r5C1xF1z.Lcom_igaworks_commerce_8s0GKjIChkfZn1:
            0x007f0800      00c5           nop                         ; I24trZx2VpS7TB8VEr26dBXNJQQFnJrV7sGf8KtC6OoTSiqGbdPmMkqYDorAiMM10gExKkeqUDqH3ARQq8Q83hr03YYbowqppA171Xl3XDcScV1FXeckaUobUWse2NGegaBb1xgxSIZrygiu80bPUXO29wdIKghuJLsrQFvvFagpQZsUZR9I.java:7
            0x007f0802      7dc5           neg-long v5, v12
            0x007f0804      4f359dc7       aput-byte v53, v157, v199
            0x007f0808      18b869571bbc.  const-wide v184:v185, 0xa36ba072bc1b5769
            0x007f0812      aa0e1b5d       rem-float v14, v27, v93
            0x007f0816      ad5bae23       mul-double v91, v174, v35
            0x007f081a      655b1dbf       sget-char v91, field+48925
            0x007f081e      5dacae89       iput-byte v12, v10, field+35246
            0x007f0822      0000           nop
            0x007f0824      030000000300   move/16 v0, v3
            0x007f082a      0000           nop
            0x007f082c      ed744c00       ^throw-verification-error v116, 0x3e0f0
            0x007f0830      59000000       iput v0, v0, Landroid/accounts/Account;->CREATOR Landroid/os/Parcelable$Creator;
            ;-- Lcom/igaworks/commerce/IgawCommerce$Currency.method.<clinit>()V:
            ;-- method.static.constructor.Lcom_igaworks_commerce_IgawCommerce_Currency.Lcom_igaworks_commerce_IgawCommerce_Currency.method._clinit___V:
            0x007f0834      22006221       new-instance v0, Lcom/igaworks/commerce/IgawCommerce$Currency; ; IgawCommerce.java:145 ; 0x46548
            0x007f0838      1a018a27       const-string v1, 0x1fb778
            0x007f083c      1a028b27       const-string v2, 0x1fb77c
            0x007f0840      7030f0c61002   invoke-direct {v0, v1, v2}, Lcom/igaworks/commerce/IgawCommerce$Currency.<init>(Ljava/lang/String;Ljava/lang/String;)V ; 0xc6f0
            0x007f0846      69001469       sput-object v0, Lcom/igaworks/commerce/IgawCommerce$Currency;->KR_KRW Lcom/igaworks/commerce/IgawCommerce$Currency;
            0x007f084a      22006221       new-instance v0, Lcom/igaworks/commerce/IgawCommerce$Currency; ; IgawCommerce.java:147 ; 0x46548
            0x007f084e      1a014971       const-string v1, 0x2ea05f
            0x007f0852      1a024b71       const-string v2, 0x2ea06d
[0x007f0780]>

[enovella]

JEB2 also fails with this sample in the decompilation

.class public bryGPqeke8RD41S7WxJNiT3P6Ak5ogOzUXT1tkqQqwOv1vovebnJHAbXeqmsNMRPaVLVwfHsO3u8zr08PxyFUd9hw1qITJ57JLIVYLaBpa6wAj08fXufp1PMYrvU0YdUb3SSsJ12pZGERL923lz1MY43OGZc5eeoQh7kCC7Hk1aiOIvhajZG
.super Object

.method public constructor <init>()V
          .registers 1
00000000  invoke-direct       Object-><init>()V, p0
00000006  return-void
.end method

.method public gCB9HY1RwJamUM0tn5Sbe3RwD0lVgxDl7tptnar9HhV1jAs8yiBtuVPPZKXETFD9OQGDKazAz4mFlKwVWl2XxvipjhgfqXJIzsC3mXchDXyCBwZBhpBE5h6Z1P9p8iQRlLKji6PHlYJPzAqJmiSc6t103Qpoy2wFFrkgFE2cSJFNTU8SRRw6()I
          .registers 2
          # Bytecode parsing errors! Not all instructions are shown, proceed carefully.
00000000  nop
00000002  invalid-opcode-79
00000004  move-object/from16  p36, p32284
.end method

.method public yAY9Vzgw8nofaAWHMNgoZMGykBxEc8AUp86q1FjzX42OlCCLGl0fq1ZtvzKgwRavy34NJRy8IztuhpBecxCPAKSI0gzsAIb7M6bXW5AN1HBnposh5Y1jddBqjEbhSHdNuQHNECNJEsvYyUoJYjlJofN8yfWQMntW6yMESf3QnIMBRtsUg8Qv()String
          .registers 2
00000000  nop
00000002  sput                p26, INVALID_FIELD_38211
00000006  sput-boolean        p158, zzhj$zza->zzKa:String
0000000A  shr-int             p60, p26, p72
0000000E  long-to-int         p4, p5
00000010  const-string        p12, "getCharSequenceExtra"
00000014  const-string/jumbo  p84, INVALID_STRING_-1927329222
0000001A  aget-wide           p62, p10, p27
0000001E  return              p30
.end method

[enovella]

@skylot @sergey-wowwow should we close this issue?

[skylot]

I think we can leave it open. I will make correct handling for bad instructions, like:

• parse whole method (ignore decode exceptions)
• add comments in code about removed opcodes and reason of removing
• implement simple dead code elimination
• for removed return insert some placeholder
• as a result these methods must be compilable