From 638578283ba35542f188fdeffc0d930c19bb3416 Mon Sep 17 00:00:00 2001 From: derrod Date: Mon, 4 Oct 2021 09:26:44 +0200 Subject: [PATCH] [core/utils/lfs] Fix auth import with now encrypted EGL user data It took way too long to find the key. It's not even hidden, I'm just dumb. --- legendary/core.py | 8 +- legendary/lfs/egl.py | 4 + legendary/utils/egl_crypt.py | 248 +++++++++++++++++++++++++++++++++++ 3 files changed, 259 insertions(+), 1 deletion(-) create mode 100644 legendary/utils/egl_crypt.py diff --git a/legendary/core.py b/legendary/core.py index 4d6ce3f..2852a5e 100644 --- a/legendary/core.py +++ b/legendary/core.py @@ -31,6 +31,7 @@ from legendary.models.game import * from legendary.models.json_manifest import JSONManifest from legendary.models.manifest import Manifest, ManifestMeta from legendary.models.chunk import Chunk +from legendary.utils.egl_crypt import decrypt_epic_data from legendary.utils.env import is_windows_or_pyi from legendary.utils.game_workarounds import is_opt_enabled, update_workarounds from legendary.utils.savegame_helper import SaveGameHelper @@ -144,7 +145,11 @@ class LegendaryCore: """Import refresh token from EGL installation and use it for logging in""" self.egl.read_config() remember_me_data = self.egl.config.get('RememberMe', 'Data') - re_data = json.loads(b64decode(remember_me_data))[0] + raw_data = b64decode(remember_me_data) + # data is encrypted + if raw_data[0] != '{': + raw_data = decrypt_epic_data(self.egl.data_key, raw_data) + re_data = json.loads(raw_data)[0] if 'Token' not in re_data: raise ValueError('No login session in config') refresh_token = re_data['Token'] @@ -240,6 +245,7 @@ class LegendaryCore: if 'egl_config' in version_info: self.egs.update_egs_params(version_info['egl_config']) self._egl_version = version_info['egl_config'].get('version', self._egl_version) + self.egl.data_key = version_info['egl_config'].get('data_key', self.egl.data_key) if game_overrides := version_info.get('game_overrides'): update_workarounds(game_overrides) if sdl_config := game_overrides.get('sdl_config'): diff --git a/legendary/lfs/egl.py b/legendary/lfs/egl.py index 4c11a9b..78503f8 100644 --- a/legendary/lfs/egl.py +++ b/legendary/lfs/egl.py @@ -10,6 +10,10 @@ from legendary.models.egl import EGLManifest class EPCLFS: + # Encryption key for JSON data + # Data is encrypted using AES-256-ECB mode + data_key = 'A09C853C9E95409BB94D707EADEFA52E' + def __init__(self): if os.name == 'nt': self.appdata_path = os.path.expandvars( diff --git a/legendary/utils/egl_crypt.py b/legendary/utils/egl_crypt.py new file mode 100644 index 0000000..43d7724 --- /dev/null +++ b/legendary/utils/egl_crypt.py @@ -0,0 +1,248 @@ +""" +Stripped down version of https://github.com/boppreh/aes which is in turn based +on https://github.com/bozhu/AES-Python with ECB decryption added. + +You should practically never roll your own crypto like this. +In this case it's just unimportant enough since all it needs to do is decrypt some data from the EGL config file. +""" + +import locale + +s_box = ( + 0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76, + 0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0, + 0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15, + 0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75, + 0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84, + 0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF, + 0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8, + 0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2, + 0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73, + 0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB, + 0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79, + 0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08, + 0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A, + 0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E, + 0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF, + 0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16, +) + +inv_s_box = ( + 0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB, + 0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB, + 0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E, + 0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25, + 0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92, + 0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84, + 0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06, + 0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B, + 0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73, + 0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E, + 0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B, + 0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4, + 0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F, + 0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF, + 0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61, + 0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D, +) + + +def sub_bytes(s): + for i in range(4): + for j in range(4): + s[i][j] = s_box[s[i][j]] + + +def inv_sub_bytes(s): + for i in range(4): + for j in range(4): + s[i][j] = inv_s_box[s[i][j]] + + +def shift_rows(s): + s[0][1], s[1][1], s[2][1], s[3][1] = s[1][1], s[2][1], s[3][1], s[0][1] + s[0][2], s[1][2], s[2][2], s[3][2] = s[2][2], s[3][2], s[0][2], s[1][2] + s[0][3], s[1][3], s[2][3], s[3][3] = s[3][3], s[0][3], s[1][3], s[2][3] + + +def inv_shift_rows(s): + s[0][1], s[1][1], s[2][1], s[3][1] = s[3][1], s[0][1], s[1][1], s[2][1] + s[0][2], s[1][2], s[2][2], s[3][2] = s[2][2], s[3][2], s[0][2], s[1][2] + s[0][3], s[1][3], s[2][3], s[3][3] = s[1][3], s[2][3], s[3][3], s[0][3] + + +def add_round_key(s, k): + for i in range(4): + for j in range(4): + s[i][j] ^= k[i][j] + + +# learned from http://cs.ucsb.edu/~koc/cs178/projects/JT/aes.c +xtime = lambda a: (((a << 1) ^ 0x1B) & 0xFF) if (a & 0x80) else (a << 1) + + +def mix_single_column(a): + # see Sec 4.1.2 in The Design of Rijndael + t = a[0] ^ a[1] ^ a[2] ^ a[3] + u = a[0] + a[0] ^= t ^ xtime(a[0] ^ a[1]) + a[1] ^= t ^ xtime(a[1] ^ a[2]) + a[2] ^= t ^ xtime(a[2] ^ a[3]) + a[3] ^= t ^ xtime(a[3] ^ u) + + +def mix_columns(s): + for i in range(4): + mix_single_column(s[i]) + + +def inv_mix_columns(s): + # see Sec 4.1.3 in The Design of Rijndael + for i in range(4): + u = xtime(xtime(s[i][0] ^ s[i][2])) + v = xtime(xtime(s[i][1] ^ s[i][3])) + s[i][0] ^= u + s[i][1] ^= v + s[i][2] ^= u + s[i][3] ^= v + + mix_columns(s) + + +r_con = ( + 0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, + 0x80, 0x1B, 0x36, 0x6C, 0xD8, 0xAB, 0x4D, 0x9A, + 0x2F, 0x5E, 0xBC, 0x63, 0xC6, 0x97, 0x35, 0x6A, + 0xD4, 0xB3, 0x7D, 0xFA, 0xEF, 0xC5, 0x91, 0x39, +) + + +def bytes2matrix(text): + """ Converts a 16-byte array into a 4x4 matrix. """ + return [list(text[i:i + 4]) for i in range(0, len(text), 4)] + + +def matrix2bytes(matrix): + """ Converts a 4x4 matrix into a 16-byte array. """ + return bytes(sum(matrix, [])) + + +def xor_bytes(a, b): + """ Returns a new byte array with the elements xor'ed. """ + return bytes(i ^ j for i, j in zip(a, b)) + + +def unpad(plaintext): + """ + Removes a PKCS#7 padding, returning the unpadded text and ensuring the + padding was correct. + """ + padding_len = plaintext[-1] + assert padding_len > 0 + message, padding = plaintext[:-padding_len], plaintext[-padding_len:] + assert all(p == padding_len for p in padding) + return message + + +def split_blocks(message, block_size=16, require_padding=True): + assert len(message) % block_size == 0 or not require_padding + return [message[i:i + 16] for i in range(0, len(message), block_size)] + + +class AES: + """ + Class for AES-128 encryption with CBC mode and PKCS#7. + + This is a raw implementation of AES, without key stretching or IV + management. Unless you need that, please use `encrypt` and `decrypt`. + """ + rounds_by_key_size = {16: 10, 24: 12, 32: 14} + + def __init__(self, master_key): + """ + Initializes the object with a given key. + """ + assert len(master_key) in AES.rounds_by_key_size + self.n_rounds = AES.rounds_by_key_size[len(master_key)] + self._key_matrices = self._expand_key(master_key) + + def _expand_key(self, master_key): + """ + Expands and returns a list of key matrices for the given master_key. + """ + # Initialize round keys with raw key material. + key_columns = bytes2matrix(master_key) + iteration_size = len(master_key) // 4 + + # Each iteration has exactly as many columns as the key material. + i = 1 + while len(key_columns) < (self.n_rounds + 1) * 4: + # Copy previous word. + word = list(key_columns[-1]) + + # Perform schedule_core once every "row". + if len(key_columns) % iteration_size == 0: + # Circular shift. + word.append(word.pop(0)) + # Map to S-BOX. + word = [s_box[b] for b in word] + # XOR with first byte of R-CON, since the others bytes of R-CON are 0. + word[0] ^= r_con[i] + i += 1 + elif len(master_key) == 32 and len(key_columns) % iteration_size == 4: + # Run word through S-box in the fourth iteration when using a + # 256-bit key. + word = [s_box[b] for b in word] + + # XOR with equivalent word from previous iteration. + word = xor_bytes(word, key_columns[-iteration_size]) + key_columns.append(word) + + # Group key words in 4x4 byte matrices. + return [key_columns[4 * i: 4 * (i + 1)] for i in range(len(key_columns) // 4)] + + def decrypt_block(self, ciphertext): + """ + Decrypts a single block of 16 byte long ciphertext. + """ + assert len(ciphertext) == 16 + + cipher_state = bytes2matrix(ciphertext) + + add_round_key(cipher_state, self._key_matrices[-1]) + inv_shift_rows(cipher_state) + inv_sub_bytes(cipher_state) + + for i in range(self.n_rounds - 1, 0, -1): + add_round_key(cipher_state, self._key_matrices[i]) + inv_mix_columns(cipher_state) + inv_shift_rows(cipher_state) + inv_sub_bytes(cipher_state) + + add_round_key(cipher_state, self._key_matrices[0]) + + return matrix2bytes(cipher_state) + + def decrypt_ecb(self, ciphertext): + """ + Decrypts `ciphertext` using ECB mode + """ + + blocks = [] + for ciphertext_block in split_blocks(ciphertext, require_padding=False): + # CTR mode decrypt: ciphertext XOR encrypt(nonce) + block = self.decrypt_block(ciphertext_block) + blocks.append(block) + + return b''.join(blocks) + + +def decrypt_epic_data(key, encrypted): + decrypted = unpad(AES(key.encode('ascii')).decrypt_ecb(encrypted)).strip(b'\x00') + # try various encodings, just to be sure + for encoding in (locale.getpreferredencoding(), 'cp1252', 'cp932', 'ascii', 'utf-8'): + try: + return decrypted.decode(encoding) + except: # ignore exception, just try the next encoding + continue + raise ValueError('Failed to decode decrypted data')