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AES ​

AES (The Advanced Encryption Standard) is an encryption algorithm used for encrypting Geometry Dash Save files on Mac and iOS

  • Geometry Dash uses ECB mode and a 256-bit key for encrypting and descrypting data

AES Key ​

  • The key used by Geometry Dash is:

  • Hexadecimal

    md
    69 70 75 39 54 55 76 35 34 79 76 5d 69 73 46 4d 68 35 40 3b 74 2e 35 77 33 34 45 32 52 79 40 7b

  • Plaintext

    ipu9TUv54yv]isFMh5@;t.5w34E2Ry@{

Padding ​

  • The plaintext data sometimes may not perfectly align and therefore, some padding is implemented

Implement Padding ​

js
// Pseudocode
pad_offset = data.length % 16;

if (pad_offset != 0) {
  pad_total = 16 - pad_offset;

  for (i = 0; i < pad_total; i++) {
    data += pad_total.toByte();
  }
}

Remove Padding ​

js
// Pseudocode
total_padding = data.last_byte();

if (total_padding < 16) {
  data = data.slice(0, data.length - total_padding);
}

Implementation ​

  • Decrypting and Encrypting data with AES is pretty simple

Encrypt ​

js
// Pseudocode
data = addPadding(data);

cipher = AES.new(
  "\x69\x70\x75\x39\x54\x55\x76\x35\x34\x79\x76\x5d\x69\x73\x46\x4d
  \x68\x35\x40\x3b\x74\x2e\x35\x77\x33\x34\x45\x32\x52\x79\x40\x7b",
  AES.MODE_ECB
);

encrypted_data = cipher.encrypt(data);

Decrypt ​

js
// Pseudocode
cipher = AES.new(
  "\x69\x70\x75\x39\x54\x55\x76\x35\x34\x79\x76\x5d\x69\x73\x46\x4d
  \x68\x35\x40\x3b\x74\x2e\x35\x77\x33\x34\x45\x32\x52\x79\x40\x7b",
  AES.MODE_ECB
);

decrypted = cipher.decrypt(data);

decrypted = removePadding(decrypted);