RIPEMD160 Class
Updated: February 2009
Represents the abstract class from which all implementations of the MD160 hash algorithm inherit.
Assembly: mscorlib (in mscorlib.dll)
Hash functions map binary strings of an arbitrary length to small binary strings of a fixed length. A cryptographic hash function has the property that it is computationally infeasible to find two distinct inputs that hash to the same value; that is, hashes of two sets of data should match if the corresponding data also matches. Small changes to the data result in large unpredictable changes in the hash.
RIPEMD-160 is a 160-bit cryptographic hash function. It is intended for use as a replacement for the 128-bit hash functions MD4, MD5, and RIPEMD. RIPEMD was developed in the framework of the EU project RIPE (RACE Integrity Primitives Evaluation, 1988-1992).
The following code example calculates the RIPEMD160 hash for all files in a directory.
Imports System Imports System.IO Imports System.Security.Cryptography Imports System.Windows.Forms Public Class HashDirectory Public Shared Sub Main(ByVal args() As String) Dim directory As String If args.Length < 1 Then Dim fdb As New FolderBrowserDialog Dim dr As DialogResult = fdb.ShowDialog() If (dr = DialogResult.OK) Then directory = fdb.SelectedPath Else Console.WriteLine("No directory selected") Return End If Else directory = args(0) End If Try ' Create a DirectoryInfo object representing the specified directory. Dim dir As New DirectoryInfo(directory) ' Get the FileInfo objects for every file in the directory. Dim files As FileInfo() = dir.GetFiles() ' Initialize a RIPE160 hash object. Dim myRIPEMD160 As RIPEMD160 = RIPEMD160Managed.Create() Dim hashValue() As Byte ' Compute and print the hash values for each file in directory. Dim fInfo As FileInfo For Each fInfo In files ' Create a fileStream for the file. Dim fileStream As FileStream = fInfo.Open(FileMode.Open) ' Be sure it's positioned to the beginning of the stream. fileStream.Position = 0 ' Compute the hash of the fileStream. hashValue = myRIPEMD160.ComputeHash(fileStream) ' Write the name of the file to the Console. Console.Write(fInfo.Name + ": ") ' Write the hash value to the Console. PrintByteArray(hashValue) ' Close the file. fileStream.Close() Next fInfo Return Catch DExc As DirectoryNotFoundException Console.WriteLine("Error: The directory specified could not be found.") Catch IOExc As IOException Console.WriteLine("Error: A file in the directory could not be accessed.") End Try End Sub ' Print the byte array in a readable format. Public Shared Sub PrintByteArray(ByVal array() As Byte) Dim i As Integer For i = 0 To array.Length - 1 Console.Write(String.Format("{0:X2}", array(i))) If i Mod 4 = 3 Then Console.Write(" ") End If Next i Console.WriteLine() End Sub 'PrintByteArray End Class
System.Security.Cryptography.HashAlgorithm
System.Security.Cryptography.RIPEMD160
System.Security.Cryptography.RIPEMD160Managed
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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