[+] Read Webpage source code

[+] Invoke the authentication function from Chrome console
```
Module["asm"]["_checkAuth"]("maro")
returns 1761
Module["asm"]["_checkAuth"]
ƒ 35() { [native code] }
```

[+] Download the Wasm file [http://assemblyme.challs.malice.fr/index.wasm](http://assemblyme.challs.malice.fr/index.wasm)

[+] Decopile the wasm file to C file using **wasmdec** [https://github.com/wwwg/wasmdec](https://github.com/wwwg/wasmdec)

There is other alternatives but this wasmdec gave me best result.

```
$wasmdec -i index.wasm -o index.c -m
```

[+] Looking at memory dump file **index.c.mem.bin**, I saw Obfuscation and Encryption related strings ... I thought it will be a pain in the ass but...I tried another way

[+] Search for return value **1761** in **index.c** file only 2 occurences in** fn_25()** function

[+] Seems that the function returns 1761 if the verification fails otherwise it returns 1690

`
...
if ( fn_47(local_0, 1616, 4);== 0) {
if ( fn_47(local_0 + 4, 1638, 4);== 0) {
if ( fn_47(local_0 + 8, 1610, 5);== 0) {
if ( fn_47(local_0 + 13, 1598, 4);== 0) {
if ( fn_47(local_0 + 17, 1681, 3);== 0) {
if ( fn_47(local_0 + 20, 1654, 9);== 0) {
global$1 = local_1;
return 1690;
} // <No else block>
} // <No else block>
} // <No else block>
} // <No else block>
} // <No else block>
} // <No else block>
...
`

**fn_47** seems to be a strncmp like function:

[-] The first argument local_0 points to the input.

[-] The second argument is the index in memory

[-] The third atgument is number of bytes to compare.

[+] I learned from index.js file that to access memory can use **Module["buffer"]**

[+] Get 4 bytes from memory at index 1616

```
new TextDecoder("utf-8").decode(Module["buffer"].slice(1616,1620))
"d51X"
```
[+] Dump the entire password

```
dec = new TextDecoder("utf-8")
dec.decode(Module["buffer"].slice(1616,1620)) + dec.decode(Module["buffer"].slice(1638,1638+4))+dec.decode(Module["buffer"].slice(1610,1610+5))+dec.decode(Module["buffer"].slice(1598,1598+4)) + dec.decode(Module["buffer"].slice(1681,1681+3))+ dec.decode(Module["buffer"].slice(1654,1654+9))
"d51XPox)1S0xk5S11W_eKXK,,,xie"
```

[+] Provide it to the web page gives

[+] Authentication is successful. The flag is NDH{password}

Maybe isn't the unintended solution regarding the encryption and the obfuscation but anyway we managed to authenticate.

Flag: **NDH{d51XPox)1S0xk5S11W_eKXK,,,xie}**

Cheers !