Bamboofox2017-tiny-strings-crypto

Question

Solution

  1. 見到佢題目話strings , 咁更係第一時間strings下佢

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    strings strings-crypto.jpg

  2. 點知比我搵到呢抽野 , 直接可以做 Decryption

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    cipher:95060BD54E0AA82E2D7842E136AA9BEA414FA71AF2A282245
    key:XOFOOBAM
    DES-CBC

###Flag

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BAMBOOFOX{51mPIepIC}

BambooFox-app

Solution

  1. 將apk放去 http://www.javadecompilers.com/apk decompile

  2. 睇番個目錄見到有個folder叫 appinventor , 好似幾有趣 , lets see~

  1. 最後係 \appinventor\ai_ss8651twtw\BambooFox\Screen1.java 搵到
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    public Object Button1$Click() {
    	runtime.setThisForm();
        if (runtime.callYailPrimitive(Scheme.numGEq, LList.list2(runtime.lookupGlobalVarInCurrentFormEnvironment(Lit3, runtime.$Stthe$Mnnull$Mnvalue$St), Lit21), Lit22, ">=") != Boolean.FALSE) {
        	runtime.setAndCoerceProperty$Ex(Lit19, Lit23, Boolean.FALSE, Lit24);
            runtime.setAndCoerceProperty$Ex(Lit19, Lit16, "QkFNQk9PRk9Ye2phVmFfNFBQX2k1X2VhU3lfdDBfRDNjMG1waTFlfQ==", Lit9);
            return runtime.callComponentMethod(Lit25, Lit26, LList.list1("Flag in somewhere"), Lit27);
        }
        runtime.callComponentMethod(Lit25, Lit26, LList.list1("Try harder!!!"), Lit28);
        return runtime.addGlobalVarToCurrentFormEnvironment(Lit3, runtime.callYailPrimitive(AddOp.$Pl, LList.list2(runtime.lookupGlobalVarInCurrentFormEnvironment(Lit3, runtime.$Stthe$Mnnull$Mnvalue$St), Lit29), Lit30, "+"));
    }

4.

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import base64
print base64.b64decode("QkFNQk9PRk9Ye2phVmFfNFBQX2k1X2VhU3lfdDBfRDNjMG1waTFlfQ==")

Flag

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BAMBOOFOX{jaVa_4PP_i5_eaSy_t0_D3c0mpi1e}