5

When I do cat on wpa_supplicant.conf file on Samsung mobiles, I see that the passwords are encrypted. But when I open the same file on LG mobiles, I can see the passwords in plain text.

This is what I see on my Galaxy S5. The information below is for my network which has a WPA password 77807780 (psk is the encrypted passkey):

network={
        ssid=""
        psk=fce6c4f64304b00c5783199bbd2b1f91
        key_mgmt=WPA-PSK
        priority=10
        frequency=2462
        autojoin=1
        usable_internet=0
        skip_internet_check=0
}

Is this a feature on Samsung mobiles? What kind of encryption is used to encrypt the password and how to decrypt them?

  • Yeah, I can confirm that it's in plain text on LG Nexus 4. Researching a bit also confirms that Samsung does encrypt/hash it, but I haven't found the method yet. – Andrew T. Jan 15 '15 at 9:04
  • On my Galaxy S5, it uses OpenSSL's EVP_Encrypt* methods with the EVP_aes_128_cbc cipher, i.e. AES with a 128-bit key in CBC mode. It makes sense since all encrypted PSKs I've seen have a length modulo 32 hex chars (32*4 bits = 128 bits, the block size of AES). No idea what's being used as the key or the IV. – johnwait Dec 26 '15 at 12:54
2

Find the following line in build.prop:

ro.securestorage.support=true

and change it to

ro.securestorage.support=false

Then reboot the device. Now retype password of your Wi-Fi network.

If your phone is rooted, you can view passwords either by reading wpa_supplicant.conf file or by installing "WiFi Key Recovery" app.

  • 1
    Hi, you need to give us some clues. I corrected BUILD.PROB -> BUILD.PROP but what's na and "WiFi key Recovery"? – Firelord Sep 12 '15 at 6:45
  • currently i don't have a device to test your solution on, but anyway that's not what i asked for i need to know the encryption type and how to decrypt an already encrypted password – MOHAMMAD RASIM Sep 12 '15 at 12:49
  • This is the same as the one above that deletes the secure storage folder, but applies to everything that uses Secure Server. – cde Jun 11 '16 at 22:57
  • @MOHAMMAD it's unlikely you will ever decrypt one once encrypted. – cde Jun 11 '16 at 22:59
3

I got a solution:

  • Go to root browser
  • Go to /etc/secure_storage/.system.wpa_supplicant then delete this folder (only ".secure.supplicant.conf"), then reboot.
  • Strange number gone

Note: It only works for Samsung devices, all saved WiFi hotspots will be lost for the first time.

3

Use wpa_supplicant's wpa_passphrase tool to create your own "real" psk. Actually, the plain-text psk (double-quoted) must be processed at every startup and config reload to generate the real, 64 hex-digit (256-bit) psk. So, using wpa_passphrase to manually create the fully-processed PSK actually optimizes wpa_supplicant's startup & config reload time. :)

About decrypting them... wpa_supplicant uses an AES-based cipher, which is well respected. I think TKIP is deprecated and possibly exploitable.

protected by Community Dec 22 '15 at 22:28

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