SQL2005支持在SQL SERVER里部署.net應(yīng)用程序了，那么以前一直寫在.net里的一些運(yùn)算如加密等已經(jīng)完全可以移到sql里來進(jìn)行了，而不需要再?gòu)某绦蛑羞\(yùn)算了，使數(shù)據(jù)庫(kù)可以和程序相對(duì)獨(dú)立開來，方便了不少。
    前陣子，需要給數(shù)據(jù)加密，所以寫了個(gè)3DES加密函數(shù)部署到SQL2005中，當(dāng)然,現(xiàn)在秘鑰也作為一個(gè)表存在在數(shù)據(jù)庫(kù)中,至于這個(gè)密鑰,以后可以考慮用usb-key使用rsa加密或者別的方式進(jìn)行加密,以保證數(shù)據(jù)安全?，F(xiàn)在先說怎么實(shí)現(xiàn)部署到sqlserver中的加密函數(shù)吧。
    新建一個(gè)項(xiàng)目。VB中的database-->SQL Server PRoject，我新建了以后叫做DESCryptoService的項(xiàng)目，之后，會(huì)讓你添加數(shù)據(jù)庫(kù)引用，選擇你要部署到的數(shù)據(jù)庫(kù)。
寫入如下代碼，就OK了

Imports System
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.SqlTypes
Imports Microsoft.SqlServer.Server
Imports System.IO
Imports System.xml
Imports System.Text
Imports System.Security.Cryptography

Partial Public Class EncryptToBase64DecryptFromBase64Class EncryptToBase64DecryptFromBase64

    <Microsoft.SqlServer.Server.SqlFunction()> _
    Public Shared Function EncryptToBase64String()Function EncryptToBase64String(ByVal stringToEncryptsql As SqlString, ByVal SEncryptionKeysql As SqlString) As SqlString
        Dim stringToEncrypt As String = CType(stringToEncryptsql, String)
        Dim SEncryptionKey As String = CType(SEncryptionKeysql, String)
        Dim IV() As Byte = {&H12, &H34, &H56, &H78, &H90, &HAB, &HCD, &HEF}
        Dim key() As Byte = {}
        Try
            key = System.Text.Encoding.UTF8.GetBytes(Left(SEncryptionKey, 8))
            Dim des As New DESCryptoServiceProvider()
            Dim inputByteArray() As Byte = Encoding.UTF8.GetBytes(stringToEncrypt)
            Dim ms As New MemoryStream()
            Dim cs As New CryptoStream(ms, des.CreateEncryptor(key, IV), CryptoStreamMode.Write)
            cs.Write(inputByteArray, 0, inputByteArray.Length)
            cs.FlushFinalBlock()
            Return Convert.ToBase64String(ms.ToArray())
        Catch e As Exception
            Return CType(e.Message, SqlString)
        End Try
    End Function

    <Microsoft.SqlServer.Server.SqlFunction()> _
        Public Shared Function DecryptFromBase64String()Function DecryptFromBase64String(ByVal stringToDecryptsql As SqlString, ByVal sEncryptionKeysql As SqlString) As SqlString
        Dim stringToDecrypt As String = CType(stringToDecryptsql, String)
        Dim sEncryptionKey As String = CType(sEncryptionKeysql, String)
        Dim inputByteArray(stringToDecrypt.Length) As Byte
        Dim IV() As Byte = {&H12, &H34, &H56, &H78, &H90, &HAB, &HCD, &HEF}
        Dim key() As Byte = {}
        Try
            key = System.Text.Encoding.UTF8.GetBytes(Left(sEncryptionKey, 8))
            Dim des As New DESCryptoServiceProvider()
            inputByteArray = Convert.FromBase64String(stringToDecrypt)
            Dim ms As New MemoryStream()
            Dim cs As New CryptoStream(ms, des.CreateDecryptor(key, IV), CryptoStreamMode.Write)
            cs.Write(inputByteArray, 0, inputByteArray.Length)
            cs.FlushFinalBlock()
            Dim encoding As System.Text.Encoding = System.Text.Encoding.UTF8
            Return encoding.GetString(ms.ToArray())
        Catch e As Exception
            Return CType(e.Message, SqlString)
        End Try
    End Function

End Class

完成之后選擇生成，部署即可

至于測(cè)試，是否可用，打開查詢分析器，執(zhí)行下面語句，
SELECT dbo.DecryptFromBase64String(dbo.EncryptToBase64String('123456','12345678'),'12345678')
如果出現(xiàn)正確的值：123456,說明成功了