Imports System

Imports System.IO

Imports System.Security.Cryptography

Imports System.Text

Imports LZStringVBNet

​

Public Module AesExample

​

    Public Sub Main()

        'response WS BPJS enkrip

        Dim response As String = "zqsl1dS0ClX6VTXw4PyvUtQbFX7kHrsyuro/XRc1acoupdtgWAqS4L6/CCwz2DwNOaepSW0We8tmfhC0yLmzHileMnbPEcHe9jhWzsDlTphAyu/DMwOJRY1mT/hPRh5r0OIl3uhmnZurQsKb5abXpmwmbXctAD3GOdEcT6nExXxs32gspQhTcaZcdWDdd9Z7Qg6Jv39Yy2IyKTjPC7s1jJuon8cRQqh42tXaOyDzOU7xeTilLjWhjfHnS1aHq5MHLTsoOlM93pQWfLglIo/ZgQvjQwlDBobb+xNxXVUl1Gp5bP+Cd3VR8Njw5DjEsRVhKBj8OERlfzZn0zKf1ajb1lB3SSJUKPj4qFQo3g5ibJyQ+HUEd2sjboh16R7Z5FUqKBDXfxskjOJJGgFLXo0+hRE9Z17hUY3Tbq6UfY8I5kZKwIcr4sABgYJ8TTThIhik"

        'consid + conspwd + timestamp request (concatenate string)

        Dim key_enc As String = "consid + conspwd + timestamp request"

        Dim keys As Byte()() = GetHashKeys(key_enc)

        Dim dekrip As String = DecryptStringFromBytes_Aes(response, keys(0), keys(1))

        Console.WriteLine("Hasil Dekrip: {0}", LZString.DecompressFromEncodedUriComponent(dekrip))

    End Sub

​

    Private Function GetHashKeys(ByVal key As String) As Byte()()

        Dim result As Byte()() = New Byte(1)() {}

        Dim enc As Encoding = Encoding.UTF8

        Dim sha2 As SHA256 = New SHA256CryptoServiceProvider()

        Dim rawKey As Byte() = enc.GetBytes(key)

        Dim rawIV As Byte() = enc.GetBytes(key)

        Dim hashKey As Byte() = sha2.ComputeHash(rawKey)

        Dim hashIV As Byte() = sha2.ComputeHash(rawIV)

        Array.Resize(hashIV, 16)

        result(0) = hashKey

        result(1) = hashIV

        Return result

    End Function

​

    Public Function EncryptStringToBytes_Aes(ByVal plainText As String, ByVal Key() As Byte, ByVal IV() As Byte) As Byte()

        ' Check arguments.

        If plainText Is Nothing OrElse plainText.Length <= 0 Then

            Throw New ArgumentNullException("plainText")

        End If

        If Key Is Nothing OrElse Key.Length <= 0 Then

            Throw New ArgumentNullException("Key")

        End If

        If IV Is Nothing OrElse IV.Length <= 0 Then

            Throw New ArgumentNullException("IV")

        End If

        Dim encrypted() As Byte

        ' Create an Aes object

        ' with the specified key and IV.

        Using aesAlg As Aes = Aes.Create()

​

            aesAlg.Key = Key

            aesAlg.IV = IV

​

            ' Create an encryptor to perform the stream transform.

            Dim encryptor As ICryptoTransform = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV)

            ' Create the streams used for encryption.

            Using msEncrypt As New MemoryStream()

                Using csEncrypt As New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)

                    Using swEncrypt As New StreamWriter(csEncrypt)

                        'Write all data to the stream.

                        swEncrypt.Write(plainText)

                    End Using

                    encrypted = msEncrypt.ToArray()

                End Using

            End Using

        End Using

​

        ' Return the encrypted bytes from the memory stream.

        Return encrypted

​

    End Function 'EncryptStringToBytes_Aes

​

Public Function DecryptStringFromBytes_Aes(ByVal cipherTextString As String, ByVal Key() As Byte, ByVal IV() As Byte) As String

        ' Check arguments.

        Dim cipherText As Byte() =  Convert.FromBase64String(cipherTextString)

        If cipherText Is Nothing OrElse cipherText.Length <= 0 Then

            Throw New ArgumentNullException("cipherText")

        End If

        If Key Is Nothing OrElse Key.Length <= 0 Then

            Throw New ArgumentNullException("Key")

        End If

        If IV Is Nothing OrElse IV.Length <= 0 Then

            Throw New ArgumentNullException("IV")

        End If

        ' Declare the string used to hold

        ' the decrypted text.

        Dim plaintext As String = Nothing

​

        ' Create an Aes object

        ' with the specified key and IV.

        Using aesAlg As Aes = Aes.Create()

            aesAlg.Key = Key

            aesAlg.IV = IV

​

            ' Create a decryptor to perform the stream transform.

            Dim decryptor As ICryptoTransform = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV)

​

            ' Create the streams used for decryption.

            Using msDecrypt As New MemoryStream(cipherText)

​

                Using csDecrypt As New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)

​

                    Using srDecrypt As New StreamReader(csDecrypt)

​

​

                        ' Read the decrypted bytes from the decrypting stream

                        ' and place them in a string.

                        plaintext = srDecrypt.ReadToEnd()

                    End Using

                End Using

            End Using

        End Using

​

        Return plaintext

​

    End Function 'DecryptStringFromBytes_Aes 

End Module