How to create a asp.net membership provider hashed password manually?

Question

I\'m using a website as a frontend and all users are authenticated with the standard ASP.NET Membership-Provider. Passwords are saved \"hashed\" within a SQL-Database.

Answer 1

Quick dirty method

Public Shared Function GetSaltKey() As String
            Dim saltBytes() As Byte
            Dim minSaltSize As Integer = 4
            Dim maxSaltSize As Integer = 8

            ' Generate a random number for the size of the salt.
            Dim random As Random
            random = New Random()

            Dim saltSize As Integer
            saltSize = random.Next(minSaltSize, maxSaltSize)

            ' Allocate a byte array, which will hold the salt.
            saltBytes = New Byte(saltSize - 1) {}

            ' Initialize a random number generator.
            Dim rng As RNGCryptoServiceProvider
            rng = New RNGCryptoServiceProvider()

            ' Fill the salt with cryptographically strong byte values.
            rng.GetNonZeroBytes(saltBytes)

            ' Convert plain text into a byte array.
            Return Convert.ToBase64String(saltBytes)
        End Function

        Public Shared Function ComputeHash(ByVal password As String, ByVal salt As String) As String

            Return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(salt & password, _
                System.Web.Configuration.FormsAuthPasswordFormat.SHA1.ToString)
        End Function

Although, the membership namespace has stuff built in for this as well, as stated by Forgotten Semicolon