賣萌黑貓的猜謎/黑貓維茲/クイズRPG 魔法使いと黒貓のウィズ(jp.colopl.quizwiz) 的逆向工程 ; 論野生技術&二次元

本文是瞎扯的，真♂相在這裡

日系卡牌遊戲都很熱啊，這貨下載量據說有500w+了

而且……日本的工程師似乎寫代碼的時候連類的名字都會取得差不多，非常方便。因此寫篇文章，也許會對以後的或現有的（？）遊戲破解帶來一點靈感。

no bullshit let’s begin XD

JAVA層

dex2jar搞一下，得到一個jar，jd-gui瀏覽jar可以定位加密類位於jp.colopl/util/Crypto.class中，代碼片段如下：

以及

從一個native method返回了SecretKeySpec對象。看來東西都在so里了

native層

IDA靜態分析libcryptograph.so和libgetlockey.so，getlockey里沒有JNI_load入口，跳過；在cryptograph里發現了名為Java_jp_colopl_util_Crypto_getKeySpec的導出@0x00000BD8 。就是它了XD，粘貼如下（沒有arm彙編高亮殘念了- -）

.text:00000BD8                 EXPORT Java_jp_colopl_util_Crypto_getKeySpec
.text:00000BD8 Java_jp_colopl_util_Crypto_getKeySpec
.text:00000BD8
.text:00000BD8 var_28          = -0x28
.text:00000BD8 var_1C          = -0x1C
.text:00000BD8
.text:00000BD8                 PUSH    {R4-R7,LR}
.text:00000BDA                 LDR     R2, [R0]
.text:00000BDC                 LDR     R1, =(unk_21FC - 0xBEA)
.text:00000BDE                 MOVS    R3, 0x29C
.text:00000BE2                 SUB     SP, SP, #0x14
.text:00000BE4                 LDR     R3, [R2,R3]
.text:00000BE6                 ADD     R1, PC
.text:00000BE8                 MOVS    R5, R0
.text:00000BEA                 BLX     R3
.text:00000BEC                 MOVS    R2, R0
.text:00000BEE                 STR     R0, [SP,#0x28+var_1C]
.text:00000BF0                 CMP     R0, #0
.text:00000BF2                 BEQ     loc_CD8
.text:00000BF4                 LDR     R2, [R5]
.text:00000BF6                 MOVS    R3, 0x2C0
.text:00000BFA                 LDR     R3, [R2,R3]
.text:00000BFC                 MOVS    R0, R5
.text:00000BFE                 MOVS    R1, #0x20
.text:00000C00                 BLX     R3
.text:00000C02                 MOVS    R2, R0
.text:00000C04                 SUBS    R7, R0, #0
.text:00000C06                 BEQ     loc_CD8
.text:00000C08                 LDR     R1, [R5]
.text:00000C0A                 MOVS    R3, 0x2E0
.text:00000C0E                 LDR     R3, [R1,R3]
.text:00000C10                 MOVS    R0, R5
.text:00000C12                 MOVS    R1, R2
.text:00000C14                 MOVS    R2, #0
.text:00000C16                 BLX     R3
.text:00000C18                 SUBS    R2, R0, #0
.text:00000C1A                 BEQ     loc_CD8
.text:00000C1C                 MOVS    R3, #0x30
.text:00000C1E                 STRB    R3, [R2]
.text:00000C20                 MOVS    R3, #0x6C
.text:00000C22                 STRB    R3, [R2,#1]
.text:00000C24                 MOVS    R3, #0x71
.text:00000C26                 STRB    R3, [R2,#2]
.text:00000C28                 MOVS    R1, #0x66
.text:00000C2A                 MOVS    R3, #0x47
.text:00000C2C                 STRB    R3, [R2,#3]
.text:00000C2E                 STRB    R1, [R2,#6]
.text:00000C30                 MOVS    R3, #0x54
.text:00000C32                 MOVS    R1, #0x4B
.text:00000C34                 STRB    R3, [R2,#4]
.text:00000C36                 STRB    R1, [R2,#8]
.text:00000C38                 MOVS    R3, #0x79
.text:00000C3A                 MOVS    R1, #0x39
.text:00000C3C                 STRB    R3, [R2,#5]
.text:00000C3E                 STRB    R3, [R2,#7]
.text:00000C40                 STRB    R1, [R2,#9]
.text:00000C42                 STRB    R3, [R2,#0x17]
.text:00000C44                 MOVS    R1, #0x49
.text:00000C46                 MOVS    R3, #0x77
.text:00000C48                 STRB    R1, [R2,#0xA]
.text:00000C4A                 STRB    R3, [R2,#0x18]
.text:00000C4C                 MOVS    R1, #0x32
.text:00000C4E                 MOVS    R3, #0x48
.text:00000C50                 STRB    R1, [R2,#0xB]
.text:00000C52                 STRB    R3, [R2,#0x19]
.text:00000C54                 MOVS    R1, #0x6B
.text:00000C56                 MOVS    R3, #0x4C
.text:00000C58                 STRB    R1, [R2,#0xC]
.text:00000C5A                 STRB    R3, [R2,#0x1A]
.text:00000C5C                 MOVS    R1, #0x76
.text:00000C5E                 MOVS    R3, #0x62
.text:00000C60                 MOVS    R0, #0x35
.text:00000C62                 MOVS    R4, #0x57
.text:00000C64                 STRB    R1, [R2,#0xD]
.text:00000C66                 STRB    R0, [R2,#0xE]
.text:00000C68                 STRB    R4, [R2,#0x11]
.text:00000C6A                 STRB    R1, [R2,#0x15]
.text:00000C6C                 STRB    R3, [R2,#0x1B]
.text:00000C6E                 STRB    R3, [R2,#0x1D]
.text:00000C70                 MOVS    R0, #0x2E
.text:00000C72                 MOVS    R4, #0x6E
.text:00000C74                 MOVS    R1, #0x63
.text:00000C76                 MOVS    R3, #0x7A
.text:00000C78                 STRB    R0, [R2,#0xF]
.text:00000C7A                 STRB    R4, [R2,#0x12]
.text:00000C7C                 STRB    R1, [R2,#0x16]
.text:00000C7E                 STRB    R3, [R2,#0x1E]
.text:00000C80                 MOVS    R0, #0x59
.text:00000C82                 MOVS    R4, #0x53
.text:00000C84                 MOVS    R1, #0x5A
.text:00000C86                 MOVS    R3, #0x4A
.text:00000C88                 STRB    R0, [R2,#0x10]
.text:00000C8A                 STRB    R0, [R2,#0x14]
.text:00000C8C                 STRB    R3, [R2,#0x1F]
.text:00000C8E                 STRB    R4, [R2,#0x13]
.text:00000C90                 STRB    R1, [R2,#0x1C]
.text:00000C92                 LDR     R1, [R5]
.text:00000C94                 MOVS    R3, 0x300
.text:00000C98                 LDR     R4, [R1,R3]
.text:00000C9A                 MOVS    R0, R5
.text:00000C9C                 MOVS    R1, R7
.text:00000C9E                 MOVS    R3, #0
.text:00000CA0                 BLX     R4
.text:00000CA2                 LDR     R3, [R5]
.text:00000CA4                 LDR     R1, =(aJavaxCryptoSpe - 0xCAE)
.text:00000CA6                 MOVS    R0, R5
.text:00000CA8                 LDR     R3, [R3,#0x18]
.text:00000CAA                 ADD     R1, PC          ; "javax/crypto/spec/SecretKeySpec"
.text:00000CAC                 BLX     R3
.text:00000CAE                 LDR     R1, [R5]
.text:00000CB0                 LDR     R2, =(aInit - 0xCBE)
.text:00000CB2                 LDR     R3, =(aBljavaLangStri - 0xCC0)
.text:00000CB4                 MOVS    R6, R0
.text:00000CB6                 ADDS    R1, #8
.text:00000CB8                 LDR     R4, [R1,#0x7C]
.text:00000CBA                 ADD     R2, PC          ; "<init>"
.text:00000CBC                 ADD     R3, PC          ; "([BLjava/lang/String;)V"
.text:00000CBE                 MOVS    R1, R6
.text:00000CC0                 MOVS    R0, R5
.text:00000CC2                 BLX     R4
.text:00000CC4                 LDR     R1, [SP,#0x28+var_1C]
.text:00000CC6                 LDR     R3, [R5]
.text:00000CC8                 MOVS    R2, R0
.text:00000CCA                 STR     R1, [SP,#0x28+var_28]
.text:00000CCC                 LDR     R4, [R3,#0x70]
.text:00000CCE                 MOVS    R0, R5
.text:00000CD0                 MOVS    R1, R6
.text:00000CD2                 MOVS    R3, R7
.text:00000CD4                 BLX     R4
.text:00000CD6                 ADDS    R2, R0, #0
.text:00000CD8
.text:00000CD8 loc_CD8                                 ; CODE XREF: Java_jp_colopl_util_Crypto_getKeySpec+1Aj
.text:00000CD8                                         ; Java_jp_colopl_util_Crypto_getKeySpec+2Ej ...
.text:00000CD8                 ADD     SP, SP, #0x14
.text:00000CDA                 MOVS    R0, R2
.text:00000CDC                 POP     {R4-R7,PC}
.text:00000CDC ; End of function Java_jp_colopl_util_Crypto_getKeySpec

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.text:00000BD8 EXPORT Java_jp_colopl_util_Crypto_getKeySpec

.text:00000BD8 Java_jp_colopl_util_Crypto_getKeySpec

.text:00000BD8

.text:00000BD8 var_28 = -0x28

.text:00000BD8 var_1C = -0x1C

.text:00000BD8

.text:00000BD8 PUSH {R4-R7,LR}

.text:00000BDA LDR R2, [R0]

.text:00000BDC LDR R1, =(unk_21FC - 0xBEA)

.text:00000BDE MOVS R3, 0x29C

.text:00000BE2 SUB SP, SP, #0x14

.text:00000BE4 LDR R3, [R2,R3]

.text:00000BE6 ADD R1, PC

.text:00000BE8 MOVS R5, R0

.text:00000BEA BLX R3

.text:00000BEC MOVS R2, R0

.text:00000BEE STR R0, [SP,#0x28+var_1C]

.text:00000BF0 CMP R0, #0

.text:00000BF2 BEQ loc_CD8

.text:00000BF4 LDR R2, [R5]

.text:00000BF6 MOVS R3, 0x2C0

.text:00000BFA LDR R3, [R2,R3]

.text:00000BFC MOVS R0, R5

.text:00000BFE MOVS R1, #0x20

.text:00000C00 BLX R3

.text:00000C02 MOVS R2, R0

.text:00000C04 SUBS R7, R0, #0

.text:00000C06 BEQ loc_CD8

.text:00000C08 LDR R1, [R5]

.text:00000C0A MOVS R3, 0x2E0

.text:00000C0E LDR R3, [R1,R3]

.text:00000C10 MOVS R0, R5

.text:00000C12 MOVS R1, R2

.text:00000C14 MOVS R2, #0

.text:00000C16 BLX R3

.text:00000C18 SUBS R2, R0, #0

.text:00000C1A BEQ loc_CD8

.text:00000C1C MOVS R3, #0x30

.text:00000C1E STRB R3, [R2]

.text:00000C20 MOVS R3, #0x6C

.text:00000C22 STRB R3, [R2,#1]

.text:00000C24 MOVS R3, #0x71

.text:00000C26 STRB R3, [R2,#2]

.text:00000C28 MOVS R1, #0x66

.text:00000C2A MOVS R3, #0x47

.text:00000C2C STRB R3, [R2,#3]

.text:00000C2E STRB R1, [R2,#6]

.text:00000C30 MOVS R3, #0x54

.text:00000C32 MOVS R1, #0x4B

.text:00000C34 STRB R3, [R2,#4]

.text:00000C36 STRB R1, [R2,#8]

.text:00000C38 MOVS R3, #0x79

.text:00000C3A MOVS R1, #0x39

.text:00000C3C STRB R3, [R2,#5]

.text:00000C3E STRB R3, [R2,#7]

.text:00000C40 STRB R1, [R2,#9]

.text:00000C42 STRB R3, [R2,#0x17]

.text:00000C44 MOVS R1, #0x49

.text:00000C46 MOVS R3, #0x77

.text:00000C48 STRB R1, [R2,#0xA]

.text:00000C4A STRB R3, [R2,#0x18]

.text:00000C4C MOVS R1, #0x32

.text:00000C4E MOVS R3, #0x48

.text:00000C50 STRB R1, [R2,#0xB]

.text:00000C52 STRB R3, [R2,#0x19]

.text:00000C54 MOVS R1, #0x6B

.text:00000C56 MOVS R3, #0x4C

.text:00000C58 STRB R1, [R2,#0xC]

.text:00000C5A STRB R3, [R2,#0x1A]

.text:00000C5C MOVS R1, #0x76

.text:00000C5E MOVS R3, #0x62

.text:00000C60 MOVS R0, #0x35

.text:00000C62 MOVS R4, #0x57

.text:00000C64 STRB R1, [R2,#0xD]

.text:00000C66 STRB R0, [R2,#0xE]

.text:00000C68 STRB R4, [R2,#0x11]

.text:00000C6A STRB R1, [R2,#0x15]

.text:00000C6C STRB R3, [R2,#0x1B]

.text:00000C6E STRB R3, [R2,#0x1D]

.text:00000C70 MOVS R0, #0x2E

.text:00000C72 MOVS R4, #0x6E

.text:00000C74 MOVS R1, #0x63

.text:00000C76 MOVS R3, #0x7A

.text:00000C78 STRB R0, [R2,#0xF]

.text:00000C7A STRB R4, [R2,#0x12]

.text:00000C7C STRB R1, [R2,#0x16]

.text:00000C7E STRB R3, [R2,#0x1E]

.text:00000C80 MOVS R0, #0x59

.text:00000C82 MOVS R4, #0x53

.text:00000C84 MOVS R1, #0x5A

.text:00000C86 MOVS R3, #0x4A

.text:00000C88 STRB R0, [R2,#0x10]

.text:00000C8A STRB R0, [R2,#0x14]

.text:00000C8C STRB R3, [R2,#0x1F]

.text:00000C8E STRB R4, [R2,#0x13]

.text:00000C90 STRB R1, [R2,#0x1C]

.text:00000C92 LDR R1, [R5]

.text:00000C94 MOVS R3, 0x300

.text:00000C98 LDR R4, [R1,R3]

.text:00000C9A MOVS R0, R5

.text:00000C9C MOVS R1, R7

.text:00000C9E MOVS R3, #0

.text:00000CA0 BLX R4

.text:00000CA2 LDR R3, [R5]

.text:00000CA4 LDR R1, =(aJavaxCryptoSpe - 0xCAE)

.text:00000CA6 MOVS R0, R5

.text:00000CA8 LDR R3, [R3,#0x18]

.text:00000CAA ADD R1, PC ; "javax/crypto/spec/SecretKeySpec"

.text:00000CAC BLX R3

.text:00000CAE LDR R1, [R5]

.text:00000CB0 LDR R2, =(aInit - 0xCBE)

.text:00000CB2 LDR R3, =(aBljavaLangStri - 0xCC0)

.text:00000CB4 MOVS R6, R0

.text:00000CB6 ADDS R1, #8

.text:00000CB8 LDR R4, [R1,#0x7C]

.text:00000CBA ADD R2, PC ; "<init>"

.text:00000CBC ADD R3, PC ; "([BLjava/lang/String;)V"

.text:00000CBE MOVS R1, R6

.text:00000CC0 MOVS R0, R5

.text:00000CC2 BLX R4

.text:00000CC4 LDR R1, [SP,#0x28+var_1C]

.text:00000CC6 LDR R3, [R5]

.text:00000CC8 MOVS R2, R0

.text:00000CCA STR R1, [SP,#0x28+var_28]

.text:00000CCC LDR R4, [R3,#0x70]

.text:00000CCE MOVS R0, R5

.text:00000CD0 MOVS R1, R6

.text:00000CD2 MOVS R3, R7

.text:00000CD4 BLX R4

.text:00000CD6 ADDS R2, R0, #0

.text:00000CD8

.text:00000CD8 loc_CD8 ; CODE XREF: Java_jp_colopl_util_Crypto_getKeySpec+1Aj

.text:00000CD8 ; Java_jp_colopl_util_Crypto_getKeySpec+2Ej ...

.text:00000CD8 ADD SP, SP, #0x14

.text:00000CDA MOVS R0, R2

.text:00000CDC POP {R4-R7,PC}

.text:00000CDC ; End of function Java_jp_colopl_util_Crypto_getKeySpec

掰彎xx王的製作團隊你們好好看看啊，這才像點樣啊好么，把AES密鑰明文存儲在so裡面和沒加密有個毛線差別啊摔！

(╯‵□′)╯︵┻━┻

瀏覽了下這段代碼之後發現，大概是在這裡調用了javax.crypto.spec.SecretKeySpec構造方法返回了SecretKeySpec對象。由於AES密鑰長度只能是16的整數倍，於是找到0x00000C8C 處的

.text:00000C8C                 STRB    R3, [R2,#0x1F]

1	.text:00000C8C STRB R3, [R2,#0x1F]

1Fh=32d，想到這可能是生成一個32位key的過程，往上找，應該就是00000C1E到00000C90 這部分的代碼了；主要邏輯是，

.text:00000C24                 MOVS    R3, #0x71   ;R3賦值asc碼為0x71的字元，即'q'
.text:00000C26                 STRB    R3, [R2,#2] ;'q'放到R2的第三位

1 2	.text:00000C24 MOVS R3, #0x71 ;R3賦值asc碼為0x71的字元，即'q' .text:00000C26 STRB R3, [R2,#2] ;'q'放到R2的第三位

python腳本多快好省

import sys
_this = sys.modules[__name__]
lines=asm.split('\n') #asm即上面那一坨彙編偽代碼
aeskey=[[]]*32#R2
for l in lines:
    print l
    l=l[31:].split(' ')
    cmd,opt,dst=l[0],l[-2],l[-1]
    if cmd=='MOVS':
        setattr(_this,opt,chr(int(dst[3:],16)))
    if cmd=='STRB':
        if ',' not in dst:
            off=0
        else:
            off=dst[1:-1].split(',')[1]
            off=int(off[1:],16)
        aeskey[off]=getattr(_this,opt)
print ''.join(aeskey)

import sys

_this = sys.modules[__name__]

lines=asm.split('\n') #asm即上面那一坨彙編偽代碼

aeskey=[[]]*32#R2

for l in lines:

print l

l=l[31:].split(' ')

cmd,opt,dst=l[0],l[-2],l[-1]

if cmd=='MOVS':

setattr(_this,opt,chr(int(dst[3:],16)))

if cmd=='STRB':

if ',' not in dst:

off=0

else:

off=dst[1:-1].split(',')[1]

off=int(off[1:],16)

aeskey[off]=getattr(_this,opt)

print ''.join(aeskey)

得到0lqGTyfyK9I2kv5.YWnSYvcywHLbZbzJ，沒試過，不知道對不對

done

然後……？

試了一下抓包然後解密，但似乎沒有padding，嘛，不管了，反正對這個遊戲不是很感興趣，霓虹語略捉急ww

（不過所有問題的題乾和答案都會在遇到妖怪的時候一起下載好，要做外掛的話應該很方便呢233

PS

java中使用>16位元組（>128bit）的AES key會被認為是欠抽的做法，從這裡下載安裝無限密鑰長度策略並覆蓋原JAVA_HOME/lib/security下的文件即可