Removind DRM from Android apps (includes Amazon's DRM)

:. Download Smali and Baksmali:

http://code.google.com/p/smali/

:. Use Smali/Baksmali to decompile/recompile the classes.dex file from the apk file

:. Cracking Android Licensing:

open com/android/vending/licensing/LicenseValidator.smali and look at handleResponse() you'll see something like:

    iget-object v0, p0, Lcom/android/vending/licensing/LicenseValidator;->mPolicy:Lcom/android/vending/licensing/Policy;

    # this function returns true/false depending on if we should allow access
    invoke-interface {v0}, Lcom/android/vending/licensing/Policy;->allowAccess()Z

    move-result v0

    # comment out this jump and protection is gone.
    # you can also make allowAccess() always return 0x1 (true)
    #if-eqz v0, :cond_0

:. Cracking Amazon Appstore DRM:

open com/amazon/android/aa/d.smali (this filename/path may be different, so try to look for strings from code below). You need to comment out 3 jumps as seen below:

	# virtual methods
	.method public final a()V
		.registers 6

		const-string v4, "LICENSE_FAILURE_CONTENT"

		iget-object v0, p0, Lcom/amazon/android/aa/d;->b:Lcom/amazon/android/o/d;

		const-string v1, "APPLICATION_LICENSE"

		invoke-virtual {v0, v1}, Lcom/amazon/android/o/d;->b(Ljava/lang/String;)Z

		move-result v0

		# Comment out first jump
		#if-eqz v0, :cond_14

		sget-object v0, Lcom/amazon/android/aa/d;->a:Lcom/amazon/android/u/a;

		const-string v1, "license verification succeeded"

		invoke-virtual {v0, v1}, Lcom/amazon/android/u/a;->a(Ljava/lang/String;)V

		:goto_13
		return-void

		:cond_14
		invoke-virtual {p0}, Lcom/amazon/android/aa/d;->f()Z

		move-result v0

		# Comment out second jump
		#if-eqz v0, :cond_1d

		invoke-virtual {p0}, Lcom/amazon/android/aa/d;->g()V

		:cond_1d
		new-instance v1, Lcom/amazon/android/l/m;

		iget-object v0, p0, Lcom/amazon/android/aa/d;->b:Lcom/amazon/android/o/d;

		const-string v2, "LICENSE_FAILURE_CONTENT"

		invoke-virtual {v0, v4}, Lcom/amazon/android/o/d;->a(Ljava/lang/String;)Ljava/lang/Object;

		move-result-object v0

		check-cast v0, Lcom/amazon/android/l/d;

		# Comment out third jump
		#if-eqz v0, :cond_3d

		iget-object v2, p0, Lcom/amazon/android/aa/d;->b:Lcom/amazon/android/o/d;

		const-string v3, "LICENSE_FAILURE_CONTENT"

		iget-object v2, v2, Lcom/amazon/android/o/d;->a:Lcom/amazon/android/o/b;

		invoke-virtual {v2, v4}, Lcom/amazon/android/o/b;->c(Ljava/lang/String;)V

		:goto_34
		invoke-direct {v1, v0}, Lcom/amazon/android/l/m;-><init>(Lcom/amazon/android/l/d;)V

		iget-object v0, p0, Lcom/amazon/android/aa/d;->c:Lcom/amazon/android/l/f;

		invoke-interface {v0, v1}, Lcom/amazon/android/l/f;->a(Lcom/amazon/android/l/a;)V

		goto :goto_13

		:cond_3d
		sget-object v0, Lcom/amazon/android/aa/f;->e:Lcom/amazon/android/l/d;

		goto :goto_34
	.end method

:. Recompile your new classes.dex file with Smali

:. Put the cracked classed.dex file in the root of the apk file


Resigning:

:. Remove META-INF folder from the apk file

:. Generate Key:
   keytool -genkey -v -keystore my-release-key.keystore -alias alias_name -keyalg RSA -validity 10000

:. Sign:
   "C:\Program Files (x86)\Java\jdk1.6.0_21\bin\jarsigner.exe" -verbose -keystore my-release-key.keystore ..\net.kairosoft.android.gamedev3en-1.apk alias_name