【VB.NET】快速哈希表（MD5、SHA、CRC32）支持输出格式文本

时间：2010-11-14 来源：夜闻香

这个方法主要封装了Cryptography内的类型，另外自己添加了比较常用的CRC32算法，以及数据转换到文本的方法。

不建议用这个类库内的函数进行大型数据的校验，因为这里的函数都必须要完全将数据读入内存之后执行算法。如果要进行大量数据的校验，建议自己使用递进算法进行计算。

Imports System.Security.Cryptography

''' <summary>计算哈希校验值，本类型内方法仅供小型计算</summary>
Public NotInheritable Class ClsoHash

    ' CRC32 算法
    Shared Function CRC32(ByVal data() As Byte) As UInt32
        Static crc As UInt32, crctbl(255) As UInt32
        If data.Length = 0 Then Return 0
        If crc = 0 Then
            For i As Short = 0 To 255
                crc = i
                For j As Byte = 0 To 7
                    If crc And 1 Then crc = (crc >> 1) Xor &HEDB88320& Else crc >>= 1
                Next
                crctbl(i) = crc
            Next
            crc = 1
        End If
        CRC32 = UInt32.MaxValue
        For Each b As Byte In data
            b = b Xor (CRC32 And &HFF)
            CRC32 >>= 8
            CRC32 = CRC32 Xor crctbl(b)
        Next
        Return Not CRC32
    End Function

    ' Adler32 算法
    Shared Function Adler32(ByVal data() As Byte, ByVal offset As Integer, ByVal count As Integer) As UInteger
        Dim checksum As UInteger = 1
        Const BASE As UInteger = 65521
        Dim s1 As UInteger = checksum And 65535
        Dim s2 As UInteger = checksum >> 16
        While count > 0
            Dim n As Integer = 3800
            If n > count Then n = count
            count -= n
            While n > 0
                s1 = s1 + CUInt((data(offset) And 255)) : offset += 1
                s2 = s2 + s1
                n -= 1
            End While
            s1 = s1 Mod BASE
            s2 = s2 Mod BASE
        End While
        Return (s2 << 16) Or s1
    End Function
    Shared Function Adler32(ByVal buffer As Byte()) As UInteger
        Return Adler32(buffer, 0, buffer.Length)
    End Function


    ' MD5算法
    Shared Function MD5(ByVal data() As Byte) As Byte()
        Return (New MD5CryptoServiceProvider).ComputeHash(data)
    End Function
    ' MD5CSP算法
    Shared Function MD5CSP(ByVal data() As Byte) As Byte()
        Return (New MD5CryptoServiceProvider).ComputeHash(data)
    End Function
    ' HMACMD5算法
    Shared Function HMACMD5(ByVal data() As Byte) As Byte()
        Return (New HMACMD5).ComputeHash(data)
    End Function
    ' HMACRIPEMD160算法
    Shared Function HMACRIPEMD160(ByVal data() As Byte) As Byte()
        Return (New HMACRIPEMD160).ComputeHash(data)
    End Function

    ' SHA 1、256、384、512算法
    Shared Function SHA1(ByVal data() As Byte) As Byte()
        Return (New SHA1Managed).ComputeHash(data)
    End Function
    Shared Function SHA256(ByVal data() As Byte) As Byte()
        Return (New SHA256Managed).ComputeHash(data)
    End Function
    Shared Function SHA384(ByVal data() As Byte) As Byte()
        Return (New SHA384Managed).ComputeHash(data)
    End Function
    Shared Function SHA512(ByVal data() As Byte) As Byte()
        Return (New SHA512Managed).ComputeHash(data)
    End Function
    ' HMACSHA 1、256、384、512算法
    Shared Function HMACSHA1(ByVal data() As Byte) As Byte()
        Return (New HMACSHA1).ComputeHash(data)
    End Function
    Shared Function HMACSHA256(ByVal data() As Byte) As Byte()
        Return (New HMACSHA256).ComputeHash(data)
    End Function
    Shared Function HMACSHA384(ByVal data() As Byte) As Byte()
        Return (New HMACSHA384).ComputeHash(data)
    End Function
    Shared Function HMACSHA512(ByVal data() As Byte) As Byte()
        Return (New HMACSHA512).ComputeHash(data)
    End Function

    ' RIPEMD160算法
    Shared Function RIPEMD160(ByVal data() As Byte) As Byte()
        Return (New RIPEMD160Managed).ComputeHash(data)
    End Function


    ' 获取各种哈希数据字符串表示
    Shared Function HashToText(ByVal data() As Byte) As String
        Dim sb As New System.Text.StringBuilder
        For Each b As Byte In data
            sb.Append(b.ToString("X2"))
        Next
        Return sb.ToString
    End Function
    ' CRC32 和 Adler32 的字符串表示
    Shared Function HashToText(ByVal uint As UInteger) As String
        Return Hex(uint)
    End Function
    Shared Function HashToText(ByVal int As Integer) As String
        Return Hex(int)
    End Function

    Shared Function HashToBase64(ByVal data() As Byte) As String
        Return Convert.ToBase64String(data)
    End Function

End Class