String Encrypt/Decrypt

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Text.RegularExpressions
' This is for password validation
Imports System.Security.Cryptography
Imports System.Configuration
' This is where the hash functions reside

Namespace BullyTracker.Common

    Public Class HashEncryption

        'public string GenerateHashvalue(string thisPassword)
        '{
        '    MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
        '    byte[] tmpSource;
        '    byte[] tmpHash;
        '    tmpSource = ASCIIEncoding.ASCII.GetBytes(thisPassword); // Turn password into byte array
        '    tmpHash = md5.ComputeHash(tmpSource);
        '    StringBuilder sOutput = new StringBuilder(tmpHash.Length);
        '    for (int i = 0; i < tmpHash.Length; i++)
        '    {
        '        sOutput.Append(tmpHash[i].ToString("X2"));  // X2 formats to hexadecimal
        '    }
        '    return sOutput.ToString();
        '}
        'public Boolean VerifyHashPassword(string thisPassword, string thisHash)
        '{
        '    Boolean IsValid = false;
        '    string tmpHash = GenerateHashvalue(thisPassword); // Call the routine on user input
        '    if (tmpHash == thisHash) IsValid = true;  // Compare to previously generated hash
        '    return IsValid;
        '}
        Public Function GenerateHashvalue(ByVal toEncrypt As String, ByVal useHashing As Boolean) As String
            Dim keyArray() As Byte
            Dim toEncryptArray() As Byte = UTF8Encoding.UTF8.GetBytes(toEncrypt)
            Dim settingsReader As System.Configuration.AppSettingsReader = New AppSettingsReader
            ' Get the key from config file
            Dim key As String = CType(settingsReader.GetValue("SecurityKey", GetType(String)),String)
            'System.Windows.Forms.MessageBox.Show(key);
            If useHashing Then
                Dim hashmd5 As MD5CryptoServiceProvider = New MD5CryptoServiceProvider
                keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key))
                hashmd5.Clear
            Else
                keyArray = UTF8Encoding.UTF8.GetBytes(key)
            End If
            Dim tdes As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider
            tdes.Key = keyArray
            tdes.Mode = CipherMode.ECB
            tdes.Padding = PaddingMode.PKCS7
            Dim cTransform As ICryptoTransform = tdes.CreateEncryptor
            Dim resultArray() As Byte = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length)
            tdes.Clear
            Return Convert.ToBase64String(resultArray, 0, resultArray.Length)
        End Function

        ''' <summary>
        ''' DeCrypt a string using dual encryption method. Return a DeCrypted clear string
        ''' </summary>
        ''' <param name="cipherString">encrypted string</param>
        ''' <param name="useHashing">Did you use hashing to encrypt this data? pass true is yes</param>
        ''' <returns></returns>
        Public Function Decrypt(ByVal cipherString As String, ByVal useHashing As Boolean) As String
            Dim keyArray() As Byte
            Dim toEncryptArray() As Byte = Convert.FromBase64String(cipherString)
            Dim settingsReader As System.Configuration.AppSettingsReader = New AppSettingsReader
            'Get your key from config file to open the lock!
            Dim key As String = CType(settingsReader.GetValue("SecurityKey", GetType(String)),String)
            If useHashing Then
                Dim hashmd5 As MD5CryptoServiceProvider = New MD5CryptoServiceProvider
                keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key))
                hashmd5.Clear
            Else
                keyArray = UTF8Encoding.UTF8.GetBytes(key)
            End If
            Dim tdes As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider
            tdes.Key = keyArray
            tdes.Mode = CipherMode.ECB
            tdes.Padding = PaddingMode.PKCS7
            Dim cTransform As ICryptoTransform = tdes.CreateDecryptor
            Dim resultArray() As Byte = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length)
            tdes.Clear
            Return UTF8Encoding.UTF8.GetString(resultArray)
        End Function
    End Class
End Namespac