Skip to content

Instantly share code, notes, and snippets.

@napsternxg
Last active August 28, 2023 13:43
Show Gist options
  • Save napsternxg/370165cc880640eaf334 to your computer and use it in GitHub Desktop.
Save napsternxg/370165cc880640eaf334 to your computer and use it in GitHub Desktop.
Decrypt the passwords saved by Totroise SVN
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' SAMPLE: Encryption and decryption using DPAPI functions.
'
' To run this sample, create a new Visual Basic.NET project using the Console
' Application template and replace the contents of the Module1.vb file with
' the code below.
'
' Go to the folder %APPDATA%\Subversion\auth\svn.simple
' Copy the Encrypted Value of the password denoted by the line below 2 lines below the line saying password
' Compile the code and put this value in a new file called InputFile.txt and in the same location where you are executing the code.
' Execute the program and it will show you the decrypted password.
'
' THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
' KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
' IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
' PURPOSE.
'
' Copyright (C) 2003 Obviex(TM). All rights reserved.
'
Imports System
Imports System.IO
Imports System.Text
Imports System.Runtime.InteropServices
Imports System.ComponentModel
Imports Microsoft.VisualBasic
Public Module Module1
' <summary>
' Encrypts and decrypts data using DPAPI functions.
' </summary>
Public Class DPAPI
' Wrapper for DPAPI CryptProtectData function.
<DllImport("crypt32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function CryptProtectData _
( _
ByRef pPlainText As DATA_BLOB, _
ByVal szDescription As String, _
ByRef pEntropy As DATA_BLOB, _
ByVal pReserved As IntPtr, _
ByRef pPrompt As CRYPTPROTECT_PROMPTSTRUCT, _
ByVal dwFlags As Integer, _
ByRef pCipherText As DATA_BLOB _
) As Boolean
End Function
' Wrapper for DPAPI CryptUnprotectData function.
<DllImport("crypt32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function CryptUnprotectData _
( _
ByRef pCipherText As DATA_BLOB, _
ByRef pszDescription As String, _
ByRef pEntropy As DATA_BLOB, _
ByVal pReserved As IntPtr, _
ByRef pPrompt As CRYPTPROTECT_PROMPTSTRUCT, _
ByVal dwFlags As Integer, _
ByRef pPlainText As DATA_BLOB _
) As Boolean
End Function
' BLOB structure used to pass data to DPAPI functions.
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
Friend Structure DATA_BLOB
Public cbData As Integer
Public pbData As IntPtr
End Structure
' Prompt structure to be used for required parameters.
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
Friend Structure CRYPTPROTECT_PROMPTSTRUCT
Public cbSize As Integer
Public dwPromptFlags As Integer
Public hwndApp As IntPtr
Public szPrompt As String
End Structure
' DPAPI key initialization flags.
Private Const CRYPTPROTECT_UI_FORBIDDEN As Integer = 1
Private Const CRYPTPROTECT_LOCAL_MACHINE As Integer = 4
' <summary>
' Initializes empty prompt structure.
' </summary>
' <param name="ps">
' Prompt parameter (which we do not actually need).
' </param>
Private Shared Sub InitPrompt _
( _
ByRef ps As CRYPTPROTECT_PROMPTSTRUCT _
)
ps.cbSize = Marshal.SizeOf(GetType(CRYPTPROTECT_PROMPTSTRUCT))
ps.dwPromptFlags = 0
ps.hwndApp = IntPtr.Zero
ps.szPrompt = Nothing
End Sub
' <summary>
' Initializes a BLOB structure from a byte array.
' </summary>
' <param name="data">
' Original data in a byte array format.
' </param>
' <param name="blob">
' Returned blob structure.
' </param>
Private Shared Sub InitBLOB _
( _
ByVal data As Byte(), _
ByRef blob As DATA_BLOB _
)
' Use empty array for null parameter.
If data Is Nothing Then
data = New Byte(0){}
End If
' Allocate memory for the BLOB data.
blob.pbData = Marshal.AllocHGlobal(data.Length)
' Make sure that memory allocation was successful.
If blob.pbData.Equals(IntPtr.Zero) Then
Throw New Exception( _
"Unable to allocate data buffer for BLOB structure.")
End If
' Specify number of bytes in the BLOB.
blob.cbData = data.Length
Marshal.Copy(data, 0, blob.pbData, data.Length)
End Sub
' Flag indicating the type of key. DPAPI terminology refers to
' key types as user store or machine store.
Public Enum KeyType
UserKey = 1
MachineKey
End Enum
' It is reasonable to set default key type to user key.
Private Shared defaultKeyType As KeyType = KeyType.UserKey
' <summary>
' Calls DPAPI CryptProtectData function to encrypt a plaintext
' string value with a user-specific key. This function does not
' specify data description and additional entropy.
' </summary>
' <param name="plainText">
' Plaintext data to be encrypted.
' </param>
' <returns>
' Encrypted value in a base64-encoded format.
' </returns>
Public Shared Function Encrypt _
( _
ByVal plainText As String _
) As String
Return Encrypt(defaultKeyType, plainText, String.Empty, String.Empty)
End Function
' <summary>
' Calls DPAPI CryptProtectData function to encrypt a plaintext
' string value. This function does not specify data description
' and additional entropy.
' </summary>
' <param name="keyType">
' Defines type of encryption key to use. When user key is
' specified, any application running under the same user account
' as the one making this call, will be able to decrypt data.
' Machine key will allow any application running on the same
' computer where data were encrypted to perform decryption.
' Note: If optional entropy is specifed, it will be required
' for decryption.
' </param>
' <param name="plainText">
' Plaintext data to be encrypted.
' </param>
' <returns>
' Encrypted value in a base64-encoded format.
' </returns>
Public Shared Function Encrypt _
( _
ByVal keyType As KeyType, _
ByVal plainText As String _
) As String
Return Encrypt(keyType, plainText, String.Empty, String.Empty)
End Function
Public Shared Function Encrypt _
( _
ByVal keyType As KeyType, _
ByVal plainText As String, _
ByVal entropy As String _
) As String
Return Encrypt(keyType, plainText, entropy, String.Empty)
End Function
' <summary>
' Calls DPAPI CryptProtectData function to encrypt a plaintext
' string value. This function does not specify data description.
' </summary>
' <param name="keyType">
' Defines type of encryption key to use. When user key is
' specified, any application running under the same user account
' as the one making this call, will be able to decrypt data.
' Machine key will allow any application running on the same
' computer where data were encrypted to perform decryption.
' Note: If optional entropy is specifed, it will be required
' for decryption.
' </param>
' <param name="plainText">
' Plaintext data to be encrypted.
' </param>
' <param name="entropy">
' Optional entropy which - if specified - will be required to
' perform decryption.
' </param>
' <returns>
' Encrypted value in a base64-encoded format.
' </returns>
Public Shared Function Encrypt _
( _
ByVal keyType As KeyType, _
ByVal plainText As String, _
ByVal entropy As String, _
ByVal description As String _
) As String
If plainText Is Nothing Then
plainText = String.Empty
End If
If entropy Is Nothing Then
entropy = String.Empty
End If
Return Convert.ToBase64String( _
Encrypt(keyType, _
Encoding.UTF8.GetBytes(plainText), _
Encoding.UTF8.GetBytes(entropy), _
description))
End Function
' <summary>
' Calls DPAPI CryptProtectData function to encrypt an array of
' plaintext bytes.
' </summary>
' <param name="keyType">
' Defines type of encryption key to use. When user key is
' specified, any application running under the same user account
' as the one making this call, will be able to decrypt data.
' Machine key will allow any application running on the same
' computer where data were encrypted to perform decryption.
' Note: If optional entropy is specifed, it will be required
' for decryption.
' </param>
' <param name="plainTextBytes">
' Plaintext data to be encrypted.
' </param>
' <param name="entropyBytes">
' Optional entropy which - if specified - will be required to
' perform decryption.
' </param>
' <param name="description">
' Optional description of data to be encrypted. If this value is
' specified, it will be stored along with encrypted data and
' returned as a separate value during decryption.
' </param>
' <returns>
' Encrypted value.
' </returns>
Public Shared Function Encrypt _
( _
ByVal keyType As KeyType, _
ByVal plainTextBytes As Byte(), _
ByVal entropyBytes As Byte(), _
ByVal description As String _
) As Byte()
' Make sure that parameters are valid.
If plainTextBytes Is Nothing Then
plainTextBytes = New Byte(0){}
End If
If entropyBytes Is Nothing Then
entropyBytes = New Byte(0){}
End If
If description Is Nothing Then
description = String.Empty
End If
' Create BLOBs to hold data.
Dim plainTextBlob As DATA_BLOB = New DATA_BLOB
Dim cipherTextBlob As DATA_BLOB = New DATA_BLOB
Dim entropyBlob As DATA_BLOB = New DATA_BLOB
' We only need prompt structure because it is a required
' parameter.
Dim prompt As _
CRYPTPROTECT_PROMPTSTRUCT = New CRYPTPROTECT_PROMPTSTRUCT
InitPrompt(prompt)
Try
' Convert plaintext bytes into a BLOB structure.
Try
InitBLOB(plainTextBytes, plainTextBlob)
Catch ex As Exception
Throw New Exception("Cannot initialize plaintext BLOB.", ex)
End Try
' Convert entropy bytes into a BLOB structure.
Try
InitBLOB(entropyBytes, entropyBlob)
Catch ex As Exception
Throw New Exception("Cannot initialize entropy BLOB.", ex)
End Try
' Disable any types of UI.
Dim flags As Integer = CRYPTPROTECT_UI_FORBIDDEN
' When using machine-specific key, set up machine flag.
If keyType = KeyType.MachineKey Then
flags = flags Or (CRYPTPROTECT_LOCAL_MACHINE)
End If
' Call DPAPI to encrypt data.
Dim success As Boolean = CryptProtectData( _
plainTextBlob, _
description, _
entropyBlob, _
IntPtr.Zero, _
prompt, _
flags, _
cipherTextBlob)
' Check the result.
If Not success Then
' If operation failed, retrieve last Win32 error.
Dim errCode As Integer = Marshal.GetLastWin32Error()
' Win32Exception will contain error message corresponding
' to the Windows error code.
Throw New Exception("CryptProtectData failed.", _
New Win32Exception(errCode))
End If
' Allocate memory to hold ciphertext.
Dim cipherTextBytes(cipherTextBlob.cbData-1) As Byte
' Copy ciphertext from the BLOB to a byte array.
Marshal.Copy(cipherTextBlob.pbData, cipherTextBytes, 0, _
cipherTextBlob.cbData)
' Return the result.
Return cipherTextBytes
Catch ex As Exception
Throw New Exception("DPAPI was unable to encrypt data.", ex)
Finally
If Not(plainTextBlob.pbData.Equals(IntPtr.Zero)) Then
Marshal.FreeHGlobal(plainTextBlob.pbData)
End If
If Not (cipherTextBlob.pbData.Equals(IntPtr.Zero)) Then
Marshal.FreeHGlobal(cipherTextBlob.pbData)
End If
If Not(entropyBlob.pbData.Equals(IntPtr.Zero)) Then
Marshal.FreeHGlobal(entropyBlob.pbData)
End If
End Try
End Function
' <summary>
' Calls DPAPI CryptUnprotectData to decrypt ciphertext bytes.
' This function does not use additional entropy and does not
' return data description.
' </summary>
' <param name="cipherText">
' Encrypted data formatted as a base64-encoded string.
' </param>
' <returns>
' Decrypted data returned as a UTF-8 string.
' </returns>
' <remarks>
' When decrypting data, it is not necessary to specify which
' type of encryption key to use: user-specific or
' machine-specific; DPAPI will figure it out by looking at
' the signature of encrypted data.
' </remarks>
Public Shared Function Decrypt _
( _
ByVal cipherText As String _
) As String
Dim description As String
Return Decrypt(cipherText, String.Empty, description)
End Function
' <summary>
' Calls DPAPI CryptUnprotectData to decrypt ciphertext bytes.
' This function does not use additional entropy.
' </summary>
' <param name="cipherText">
' Encrypted data formatted as a base64-encoded string.
' </param>
' <param name="description">
' Returned description of data specified during encryption.
' </param>
' <returns>
' Decrypted data returned as a UTF-8 string.
' </returns>
' <remarks>
' When decrypting data, it is not necessary to specify which
' type of encryption key to use: user-specific or
' machine-specific; DPAPI will figure it out by looking at
' the signature of encrypted data.
' </remarks>
Public Shared Function Decrypt _
( _
ByVal cipherText As String, _
ByRef description As String _
) As String
Return Decrypt(cipherText, String.Empty, description)
End Function
' <summary>
' Calls DPAPI CryptUnprotectData to decrypt ciphertext bytes.
' </summary>
' <param name="cipherText">
' Encrypted data formatted as a base64-encoded string.
' </param>
' <param name="entropy">
' Optional entropy, which is required if it was specified during
' encryption.
' </param>
' <param name="description">
' Returned description of data specified during encryption.
' </param>
' <returns>
' Decrypted data returned as a UTF-8 string.
' </returns>
' <remarks>
' When decrypting data, it is not necessary to specify which
' type of encryption key to use: user-specific or
' machine-specific; DPAPI will figure it out by looking at
' the signature of encrypted data.
' </remarks>
Public Shared Function Decrypt _
( _
ByVal cipherText As String, _
ByVal entropy As String, _
ByRef description As String _
) As String
' Make sure that parameters are valid.
If entropy Is Nothing Then
entropy = String.Empty
End If
Return Encoding.UTF8.GetString( _
Decrypt(Convert.FromBase64String(cipherText), _
Encoding.UTF8.GetBytes(entropy), description))
End Function
' <summary>
' Calls DPAPI CryptUnprotectData to decrypt ciphertext bytes.
' </summary>
' <param name="cipherTextBytes">
' Encrypted data.
' </param>
' <param name="entropyBytes">
' Optional entropy, which is required if it was specified during
' encryption.
' </param>
' <param name="description">
' Returned description of data specified during encryption.
' </param>
' <returns>
' Decrypted data bytes.
' </returns>
' <remarks>
' When decrypting data, it is not necessary to specify which
' type of encryption key to use: user-specific or
' machine-specific; DPAPI will figure it out by looking at
' the signature of encrypted data.
' </remarks>
Public Shared Function Decrypt _
( _
ByVal cipherTextBytes As Byte(), _
ByVal entropyBytes As Byte(), _
ByRef description As String _
) As Byte()
' Create BLOBs to hold data.
Dim plainTextBlob As DATA_BLOB = New DATA_BLOB
Dim cipherTextBlob As DATA_BLOB = New DATA_BLOB
Dim entropyBlob As DATA_BLOB = New DATA_BLOB
' We only need prompt structure because it is a required
' parameter.
Dim prompt As _
CRYPTPROTECT_PROMPTSTRUCT = New CRYPTPROTECT_PROMPTSTRUCT
InitPrompt(prompt)
' Initialize description string.
description = String.Empty
Try
' Convert ciphertext bytes into a BLOB structure.
Try
InitBLOB(cipherTextBytes, cipherTextBlob)
Catch ex As Exception
Throw New Exception("Cannot initialize ciphertext BLOB.", ex)
End Try
' Convert entropy bytes into a BLOB structure.
Try
InitBLOB(entropyBytes, entropyBlob)
Catch ex As Exception
Throw New Exception("Cannot initialize entropy BLOB.", ex)
End Try
' Disable any types of UI. CryptUnprotectData does not
' mention CRYPTPROTECT_LOCAL_MACHINE flag in the list of
' supported flags so we will not set it up.
Dim flags As Integer = CRYPTPROTECT_UI_FORBIDDEN
' Call DPAPI to decrypt data.
Dim success As Boolean = CryptUnprotectData( _
cipherTextBlob, _
description, _
entropyBlob, _
IntPtr.Zero, _
prompt, _
flags, _
plainTextBlob)
' Check the result.
If Not success Then
' If operation failed, retrieve last Win32 error.
Dim errCode As Integer = Marshal.GetLastWin32Error()
' Win32Exception will contain error message corresponding
' to the Windows error code.
Throw New Exception("CryptUnprotectData failed.", _
New Win32Exception(errCode))
End If
' Allocate memory to hold plaintext.
Dim plainTextBytes(plainTextBlob.cbData-1) As Byte
' Copy ciphertext from the BLOB to a byte array.
Marshal.Copy(plainTextBlob.pbData, plainTextBytes, 0, _
plainTextBlob.cbData)
' Return the result.
Return plainTextBytes
Catch ex As Exception
Throw New Exception("DPAPI was unable to decrypt data.", ex)
' Free all memory allocated for BLOBs.
Finally
If Not(plainTextBlob.pbData.Equals(IntPtr.Zero)) Then
Marshal.FreeHGlobal(plainTextBlob.pbData)
End If
If Not(cipherTextBlob.pbData.Equals(IntPtr.Zero)) Then
Marshal.FreeHGlobal(cipherTextBlob.pbData)
End If
If Not(entropyBlob.pbData.Equals(IntPtr.Zero)) Then
Marshal.FreeHGlobal(entropyBlob.pbData)
End If
End Try
End Function
End Class
' <summary>
' The main entry point for the application.
' </summary>
Sub Main(ByVal args As String())
Try
Dim text As String = "Hello World"
Dim entropy As String = Nothing
Dim description As String
Dim encrypted As String
Dim decrypted As String
Console.WriteLine("Plaintext: {0}" & Chr(13) & Chr(10), text)
' Call DPAPI to encrypt data with user-specific key.
encrypted = DPAPI.Encrypt( DPAPI.KeyType.UserKey, _
text, entropy, "My Data")
Console.WriteLine("Encrypted: {0}" & Chr(13) & Chr(10), encrypted)
Dim sr As New StreamReader("InputFile.txt")
encrypted = sr.ReadLine()
' Call DPAPI to decrypt data.
decrypted = DPAPI.Decrypt(encrypted, entropy, description)
Console.WriteLine("Decrypted: {0} <<<{1}>>>" & Chr(13) & Chr(10), _
decrypted, description)
text = Console.ReadLine()
Catch ex As Exception
While Not (ex Is Nothing)
Console.WriteLine(ex.Message)
ex = ex.InnerException
End While
End Try
End Sub
End Module
'
' END OF FILE
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
@tony-at-rcxrules
Copy link

worked great.. thanks!!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment