Android
the classes.dex file is corruption,most of the Java discompiler will miss one method which is the truly decrypt function .in IDA you can view the smali code.
CODE:000005E0 sget-byte v0, System_out # Size of bytecode (in 16-bit units): 0x64
CODE:000005E4 const/16 v0, 0x10
CODE:000005E8 .prologue_end
CODE:000005E8 .line 88
CODE:000005E8 new-array v1, v0, <t: byte[]>
CODE:000005EC fill-array-data v1, word_67C
CODE:000005F2 .line 90
CODE:000005F2 new-array v2, v0, <t: byte[]>
CODE:000005F6 fill-array-data v2, word_694
CODE:000005FC .line 92
CODE:000005FC new-instance v3, <t: StringBuilder>
CODE:00000600 invoke-direct {v3}, <void StringBuilder.<init>() imp. @ _def_StringBuilder__init_@V>
CODE:00000606 .line 94
CODE:00000606 const/4 v0, 0
CODE:00000608
CODE:00000608 loc_608: # CODE XREF: CODE:00000624�j
CODE:00000608 array-length v4, v1
CODE:0000060A if-ge v0, v4, loc_626
CODE:0000060E .line 96
CODE:0000060E aget-byte v4, v1, v0
CODE:00000612 aget-byte v5, v2, v0
CODE:00000616 xor-int/2addr v4, v5
CODE:00000618 .line 97
CODE:00000618 int-to-char v4, v4
CODE:0000061A invoke-virtual {v3, v4}, <ref StringBuilder.append(char) imp. @ _def_StringBuilder_append@LC>
CODE:00000620 .line 94
CODE:00000620 add-int/lit8 v0, v0, 1
CODE:00000624 goto loc_608
CODE:00000626 # ---------------------------------------------------------------------------
CODE:00000626
CODE:00000626 loc_626: # CODE XREF: CODE:0000060A�j
CODE:00000626 .line 100
CODE:00000626 new-instance v0, <t: SecretKeySpec>
CODE:0000062A new-instance v1, <t: String>
CODE:0000062E invoke-direct {v1, v3}, <void String.<init>(ref) imp. @ _def_String__init_@VL>
CODE:00000634 invoke-virtual {v1}, <ref String.getBytes() imp. @ _def_String_getBytes@L>
CODE:0000063A move-result-object v1
CODE:0000063C const-string v2, aAes # "AES"
CODE:00000640 invoke-direct {v0, v1, v2}, <void SecretKeySpec.<init>(ref, ref) imp. @ _def_SecretKeySpec__init_@VLL>
CODE:00000646 .line 101
CODE:00000646 const-string v1, aAesEcbPkcs5pad # "AES/ECB/PKCS5Padding"
CODE:0000064A invoke-static {v1}, <ref Cipher.getInstance(ref) imp. @ _def_Cipher_getInstance@LL>
CODE:00000650 move-result-object v1
CODE:00000652 .line 102
CODE:00000652 const-string v2, a8bl8gduxqjbtqr # "8Bl8GDuXQJbTQrjT6LfQdw=="
CODE:00000656 .line 104
CODE:00000656 const/4 v3, 2
CODE:00000658 invoke-virtual {v1, v3, v0}, <void Cipher.init(int, ref) imp. @ _def_Cipher_init@VIL>
CODE:0000065E .line 105
CODE:0000065E invoke-static {v2}, <ref DatatypeConverter.parseBase64Binary(ref) imp. @ _def_DatatypeConverter_parseBase64Binary@LL>
CODE:00000664 move-result-object v0
CODE:00000666 invoke-virtual {v1, v0}, <ref Cipher.doFinal(ref) imp. @ _def_Cipher_doFinal@LL>
CODE:0000066C move-result-object v0
CODE:0000066E .line 106
CODE:0000066E new-instance v1, <t: String>
CODE:00000672 invoke-direct {v1, v0}, <void String.<init>(ref) imp. @ _def_String__init_@VL_0>
CODE:00000678 .line 107
CODE:00000678 return-voidthe python implement as follows:
from Crypto.Cipher import AES
import base64
iv="\x00"*16
x1=[0x00, 0x03, 0x01, 0x00, 0x10, 0x00, 0x00, 0x00,0x61, 0x30, 0x31, 0x62, 0x32,0x63, 0x33, 0x64, 0x34, 0x65,0x35, 0x66, 0x36, 0x67, 0x37, 0x68]
x2=[0x00, 0x03, 0x01, 0x00,0x10, 0x00, 0x00, 0x00, 0x12, 0x5B, 0x42, 0x0F,0x41, 0x11,0x5B, 0x01, 0x46, 0x0B, 0x46, 0x03, 0x59, 0x15, 0x5C, 0x09]
for i in range(0,24):
x1[i] = x1[i] ^ x2[i]
key =''.join(map(chr,x1))
encrypted = base64.b64decode('8Bl8GDuXQJbTQrjT6LfQdw==')
cipher = AES.new(key[8:],AES.MODE_CBC,iv)
print cipher.decrypt(encrypted)