Agfdhyk

I'm working on programm on VB.net to retrieve data from Firefox browser. I have an error while trying to use "PK11SDR_Decrypt" method from nss3.lib. "PK11SDR_Decrypt" returns -1. I don't have master password. I think that the problem in Ctypes/marshalling/base64 decoding. This is the code of function.

Public Function DecryptFF(ByVal str As String)

    On Error Resume Next

    Dim tSecDec As New TSECItem

    Dim e As Integer

    Dim sb As New System.Text.StringBuilder(str)

    Dim hi2 As Integer = NSSBase64_DecodeBuffer(IntPtr.Zero, IntPtr.Zero, sb, sb.Length)

    Dim item As TSECItem = DirectCast(Marshal.PtrToStructure(New IntPtr(hi2), GetType(TSECItem)), TSECItem)

    e = PK11SDR_Decrypt(item, tSecDec, 0)

    If e = 0 Then

        If tSecDec.SECItemLen <> 0 Then

            Dim mozDecryptedData = New Byte(tSecDec.SECItemLen - 1) {}

            Marshal.Copy(New IntPtr(tSecDec.SECItemData), mozDecryptedData, 0, tSecDec.SECItemLen)

            Return Encoding.UTF8.GetString(mozDecryptedData)

        End If

    End If

    Return String.Empty

End Function

And other code part.

Public NSS3 As IntPtr

Public hModuleList As New List(Of IntPtr)



<StructLayout(LayoutKind.Sequential)>

Public Structure TSECItem

    Public SECItemType As Integer

    Public SECItemData As Integer

    Public SECItemLen As Integer

End Structure



Public Function NSS_Init(ByVal configdir As String) As Long

    Dim PathM = FindFirefoxInstallationPath()

    hModuleList.Add(LoadLibrary(PathM & "msvcp140.dll"))

    hModuleList.Add(LoadLibrary(PathM & "mozglue.dll"))

    hModuleList.Add(LoadLibrary(PathM & "mozavutils.dll"))

    NSS3 = LoadLibrary(PathM & "nss3.dll")

    hModuleList.Add(NSS3)

    Return CreateAPI(Of DLLFunctionDelegate)(NSS3, "NSS_Init")(configdir)

End Function



Public Function CreateAPI(Of T)(ByVal hModule As IntPtr, ByVal method As String) As T 'Simple overload to avoid loading the same library every time

    Return DirectCast(DirectCast(Marshal.GetDelegateForFunctionPointer(GetProcAddress(hModule, method), GetType(T)), Object), T)

End Function



Public Function NSSBase64_DecodeBuffer(ByVal arenaOpt As IntPtr, ByVal outItemOpt As IntPtr, ByVal inStr As System.Text.StringBuilder, ByVal inLen As Integer) As Integer

    Dim pProc As IntPtr = GetProcAddress(NSS3, "NSSBase64_DecodeBuffer")

    Dim dll As DLLFunctionDelegate4 = DirectCast(Runtime.InteropServices.Marshal.GetDelegateForFunctionPointer(pProc, GetType(DLLFunctionDelegate4)), DLLFunctionDelegate4)

    Return dll(arenaOpt, outItemOpt, inStr, inLen)

End Function



Public Function PK11SDR_Decrypt(ByRef data As TSECItem, ByRef result As TSECItem, ByVal cx As Integer) As Integer

    Dim pProc As IntPtr = GetProcAddress(NSS3, "PK11SDR_Decrypt")

    Dim dll As DLLFunctionDelegate5 = DirectCast(Marshal.GetDelegateForFunctionPointer(pProc, GetType(DLLFunctionDelegate5)), DLLFunctionDelegate5)

    Return dll(data, result, cx)

End Function



<UnmanagedFunctionPointer(CallingConvention.Cdecl)>

Public Delegate Function DLLFunctionDelegate5(ByRef data As TSECItem, ByRef result As TSECItem, ByVal cx As Integer) As Integer

<UnmanagedFunctionPointer(CallingConvention.Cdecl)>

Public Delegate Function DLLFunctionDelegate6() As Long



Public Function NSS_Shutdown() As Long

    Return CreateAPI(Of DLLFunctionDelegate6)(NSS3, "NSS_Shutdown")()

End Function



<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Auto)>

Public Shared Function LoadLibrary(ByVal dllFilePath As String) As IntPtr

End Function



<DllImport("kernel32.dll", SetLastError:=True, EntryPoint:="FreeLibrary")>

Public Shared Function FreeLibrary(ByVal hModule As IntPtr) As Boolean

End Function



<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Ansi, ExactSpelling:=True)>

Public Shared Function GetProcAddress(ByVal hModule As IntPtr, ByVal procName As String) As IntPtr

End Function

DecryptFF get as argument the encrypted login fron logins.json file. Here is the part of code

Dim JSONRegex As New Regex("""(hostname|encryptedPassword|encryptedUsername)"":""(.*?)""")

Dim mozMC = JSONRegex.Matches(Logins)

For I = 0 To mozMC.Count - 1 Step 3

Dim host = mozMC(I).Groups(2).Value

Dim usr = mozMC(I + 1).Groups(2).Value

Dim pas = mozMC(I + 2).Groups(2).Value

Account = (DecryptFF(usr))

Thank you for your help!