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HMACSHA512 類別

定義

使用 SHA512 雜湊函式,計算雜湊式訊息驗證碼 (Hash-based Message Authentication Code,HMAC)。

public ref class HMACSHA512 : System::Security::Cryptography::HMAC
[System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
public class HMACSHA512 : System.Security.Cryptography.HMAC
public class HMACSHA512 : System.Security.Cryptography.HMAC
[System.Runtime.InteropServices.ComVisible(true)]
public class HMACSHA512 : System.Security.Cryptography.HMAC
[<System.Runtime.Versioning.UnsupportedOSPlatform("browser")>]
type HMACSHA512 = class
    inherit HMAC
type HMACSHA512 = class
    inherit HMAC
[<System.Runtime.InteropServices.ComVisible(true)>]
type HMACSHA512 = class
    inherit HMAC
Public Class HMACSHA512
Inherits HMAC
繼承
屬性

範例

下列範例示範如何使用 對象簽署檔案 HMACSHA512 ,以及如何驗證檔案。

using namespace System;
using namespace System::IO;
using namespace System::Security::Cryptography;

// Computes a keyed hash for a source file, creates a target file with the keyed hash
// prepended to the contents of the source file, then decrypts the file and compares
// the source and the decrypted files.
void EncodeFile( array<Byte>^key, String^ sourceFile, String^ destFile )
{
   
   // Initialize the keyed hash object.
   HMACSHA512^ myhmacsha512 = gcnew HMACSHA512( key );
   FileStream^ inStream = gcnew FileStream( sourceFile,FileMode::Open );
   FileStream^ outStream = gcnew FileStream( destFile,FileMode::Create );
   
   // Compute the hash of the input file.
   array<Byte>^hashValue = myhmacsha512->ComputeHash( inStream );
   
   // Reset inStream to the beginning of the file.
   inStream->Position = 0;
   
   // Write the computed hash value to the output file.
   outStream->Write( hashValue, 0, hashValue->Length );
   
   // Copy the contents of the sourceFile to the destFile.
   int bytesRead;
   
   // read 1K at a time
   array<Byte>^buffer = gcnew array<Byte>(1024);
   do
   {
      
      // Read from the wrapping CryptoStream.
      bytesRead = inStream->Read( buffer, 0, 1024 );
      outStream->Write( buffer, 0, bytesRead );
   }
   while ( bytesRead > 0 );

   myhmacsha512->Clear();
   
   // Close the streams
   inStream->Close();
   outStream->Close();
   return;
} // end EncodeFile



// Decrypt the encoded file and compare to original file.
bool DecodeFile( array<Byte>^key, String^ sourceFile )
{
   
   // Initialize the keyed hash object. 
   HMACSHA512^ hmacsha512 = gcnew HMACSHA512( key );
   
   // Create an array to hold the keyed hash value read from the file.
   array<Byte>^storedHash = gcnew array<Byte>(hmacsha512->HashSize / 8);
   
   // Create a FileStream for the source file.
   FileStream^ inStream = gcnew FileStream( sourceFile,FileMode::Open );
   
   // Read in the storedHash.
   inStream->Read( storedHash, 0, storedHash->Length );
   
   // Compute the hash of the remaining contents of the file.
   // The stream is properly positioned at the beginning of the content, 
   // immediately after the stored hash value.
   array<Byte>^computedHash = hmacsha512->ComputeHash( inStream );
   
   // compare the computed hash with the stored value
   bool err = false;
   for ( int i = 0; i < storedHash->Length; i++ )
   {
      if ( computedHash[ i ] != storedHash[ i ] )
      {
         err = true;
      }
   }
   if (err)
        {
            Console::WriteLine("Hash values differ! Encoded file has been tampered with!");
            return false;
        }
        else
        {
            Console::WriteLine("Hash values agree -- no tampering occurred.");
            return true;
        }

} //end DecodeFile


int main()
{
   array<String^>^Fileargs = Environment::GetCommandLineArgs();
   String^ usageText = "Usage: HMACSHA512 inputfile.txt encryptedfile.hsh\nYou must specify the two file names. Only the first file must exist.\n";
   
   //If no file names are specified, write usage text.
   if ( Fileargs->Length < 3 )
   {
      Console::WriteLine( usageText );
   }
   else
   {
      try
      {
         
         // Create a random key using a random number generator. This would be the
         //  secret key shared by sender and receiver.
         array<Byte>^secretkey = gcnew array<Byte>(64);
         
         //RNGCryptoServiceProvider is an implementation of a random number generator.
         RNGCryptoServiceProvider^ rng = gcnew RNGCryptoServiceProvider;
         
         // The array is now filled with cryptographically strong random bytes.
         rng->GetBytes( secretkey );
         
         // Use the secret key to encode the message file.
         EncodeFile( secretkey, Fileargs[ 1 ], Fileargs[ 2 ] );
         
         // Take the encoded file and decode
         DecodeFile( secretkey, Fileargs[ 2 ] );
      }
      catch ( IOException^ e ) 
      {
         Console::WriteLine( "Error: File not found", e );
      }

   }
} //end main
using System;
using System.IO;
using System.Security.Cryptography;

public class HMACSHA512example
{

    public static void Main(string[] Fileargs)
    {
        string dataFile;
        string signedFile;
        //If no file names are specified, create them.
        if (Fileargs.Length < 2)
        {
            dataFile = @"text.txt";
            signedFile = "signedFile.enc";

            if (!File.Exists(dataFile))
            {
                // Create a file to write to.
                using (StreamWriter sw = File.CreateText(dataFile))
                {
                    sw.WriteLine("Here is a message to sign");
                }
            }
        }
        else
        {
            dataFile = Fileargs[0];
            signedFile = Fileargs[1];
        }
        try
        {
            // Create a random key using a random number generator. This would be the
            //  secret key shared by sender and receiver.
            byte[] secretkey = new Byte[64];
            //RNGCryptoServiceProvider is an implementation of a random number generator.
            using (RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider())
            {
                // The array is now filled with cryptographically strong random bytes.
                rng.GetBytes(secretkey);

                // Use the secret key to sign the message file.
                SignFile(secretkey, dataFile, signedFile);

                // Verify the signed file
                VerifyFile(secretkey, signedFile);
            }
        }
        catch (IOException e)
        {
            Console.WriteLine("Error: File not found", e);
        }
    }  //end main
    // Computes a keyed hash for a source file and creates a target file with the keyed hash
    // prepended to the contents of the source file.
    public static void SignFile(byte[] key, String sourceFile, String destFile)
    {
        // Initialize the keyed hash object.
        using (HMACSHA512 hmac = new HMACSHA512(key))
        {
            using (FileStream inStream = new FileStream(sourceFile, FileMode.Open))
            {
                using (FileStream outStream = new FileStream(destFile, FileMode.Create))
                {
                    // Compute the hash of the input file.
                    byte[] hashValue = hmac.ComputeHash(inStream);
                    // Reset inStream to the beginning of the file.
                    inStream.Position = 0;
                    // Write the computed hash value to the output file.
                    outStream.Write(hashValue, 0, hashValue.Length);
                    // Copy the contents of the sourceFile to the destFile.
                    int bytesRead;
                    // read 1K at a time
                    byte[] buffer = new byte[1024];
                    do
                    {
                        // Read from the wrapping CryptoStream.
                        bytesRead = inStream.Read(buffer, 0, 1024);
                        outStream.Write(buffer, 0, bytesRead);
                    } while (bytesRead > 0);
                }
            }
        }
        return;
    } // end SignFile

    // Compares the key in the source file with a new key created for the data portion of the file. If the keys
    // compare the data has not been tampered with.
    public static bool VerifyFile(byte[] key, String sourceFile)
    {
        bool err = false;
        // Initialize the keyed hash object.
        using (HMACSHA512 hmac = new HMACSHA512(key))
        {
            // Create an array to hold the keyed hash value read from the file.
            byte[] storedHash = new byte[hmac.HashSize / 8];
            // Create a FileStream for the source file.
            using (FileStream inStream = new FileStream(sourceFile, FileMode.Open))
            {
                // Read in the storedHash.
                inStream.Read(storedHash, 0, storedHash.Length);
                // Compute the hash of the remaining contents of the file.
                // The stream is properly positioned at the beginning of the content,
                // immediately after the stored hash value.
                byte[] computedHash = hmac.ComputeHash(inStream);
                // compare the computed hash with the stored value

                for (int i = 0; i < storedHash.Length; i++)
                {
                    if (computedHash[i] != storedHash[i])
                    {
                        err = true;
                    }
                }
            }
        }
        if (err)
        {
            Console.WriteLine("Hash values differ! Signed file has been tampered with!");
            return false;
        }
        else
        {
            Console.WriteLine("Hash values agree -- no tampering occurred.");
            return true;
        }
    } //end VerifyFile
} //end class
Imports System.IO
Imports System.Security.Cryptography

Public Class HMACSHA5126example

    Public Shared Sub Main(ByVal Fileargs() As String)
        Dim dataFile As String
        Dim signedFile As String
        'If no file names are specified, create them.
        If Fileargs.Length < 2 Then
            dataFile = "text.txt"
            signedFile = "signedFile.enc"

            If Not File.Exists(dataFile) Then
                ' Create a file to write to.
                Using sw As StreamWriter = File.CreateText(dataFile)
                    sw.WriteLine("Here is a message to sign")
                End Using
            End If

        Else
            dataFile = Fileargs(0)
            signedFile = Fileargs(1)
        End If
        Try
            ' Create a random key using a random number generator. This would be the
            '  secret key shared by sender and receiver.
            Dim secretkey() As Byte = New [Byte](63) {}
            'RNGCryptoServiceProvider is an implementation of a random number generator.
            Using rng As New RNGCryptoServiceProvider()
                ' The array is now filled with cryptographically strong random bytes.
                rng.GetBytes(secretkey)

                ' Use the secret key to encode the message file.
                SignFile(secretkey, dataFile, signedFile)

                ' Take the encoded file and decode
                VerifyFile(secretkey, signedFile)
            End Using
        Catch e As IOException
            Console.WriteLine("Error: File not found", e)
        End Try

    End Sub

    ' Computes a keyed hash for a source file and creates a target file with the keyed hash
    ' prepended to the contents of the source file. 
    Public Shared Sub SignFile(ByVal key() As Byte, ByVal sourceFile As String, ByVal destFile As String)
        ' Initialize the keyed hash object.
        Using myhmac As New HMACSHA512(key)
            Using inStream As New FileStream(sourceFile, FileMode.Open)
                Using outStream As New FileStream(destFile, FileMode.Create)
                    ' Compute the hash of the input file.
                    Dim hashValue As Byte() = myhmac.ComputeHash(inStream)
                    ' Reset inStream to the beginning of the file.
                    inStream.Position = 0
                    ' Write the computed hash value to the output file.
                    outStream.Write(hashValue, 0, hashValue.Length)
                    ' Copy the contents of the sourceFile to the destFile.
                    Dim bytesRead As Integer
                    ' read 1K at a time
                    Dim buffer(1023) As Byte
                    Do
                        ' Read from the wrapping CryptoStream.
                        bytesRead = inStream.Read(buffer, 0, 1024)
                        outStream.Write(buffer, 0, bytesRead)
                    Loop While bytesRead > 0
                End Using
            End Using
        End Using
        Return

    End Sub
    ' end SignFile

    ' Compares the key in the source file with a new key created for the data portion of the file. If the keys 
    ' compare the data has not been tampered with.
    Public Shared Function VerifyFile(ByVal key() As Byte, ByVal sourceFile As String) As Boolean
        Dim err As Boolean = False
        ' Initialize the keyed hash object. 
        Using hmac As New HMACSHA512(key)
            ' Create an array to hold the keyed hash value read from the file.
            Dim storedHash(hmac.HashSize / 8 - 1) As Byte
            ' Create a FileStream for the source file.
            Using inStream As New FileStream(sourceFile, FileMode.Open)
                ' Read in the storedHash.
                inStream.Read(storedHash, 0, storedHash.Length - 1)
                ' Compute the hash of the remaining contents of the file.
                ' The stream is properly positioned at the beginning of the content, 
                ' immediately after the stored hash value.
                Dim computedHash As Byte() = hmac.ComputeHash(inStream)
                ' compare the computed hash with the stored value
                Dim i As Integer
                For i = 0 To storedHash.Length - 2
                    If computedHash(i) <> storedHash(i) Then
                        err = True
                    End If
                Next i
            End Using
        End Using
        If err Then
            Console.WriteLine("Hash values differ! Signed file has been tampered with!")
            Return False
        Else
            Console.WriteLine("Hash values agree -- no tampering occurred.")
            Return True
        End If

    End Function 'VerifyFile 
End Class
'end class

備註

HMACSHA512 是從 SHA-512 哈希函式建構的索引鍵哈希演算法類型,用來做為哈希型訊息驗證程式代碼 (HMAC) 。 HMAC 程式會混合秘密金鑰與訊息數據,並哈希結果。 哈希值會再次與秘密密鑰混合,然後再哈希一次。 輸出哈希的長度為512位。

HMAC 可用來判斷透過不安全通道傳送的訊息是否已遭到竄改,前提是傳送者和接收者共用秘密密鑰。 傳送者會計算原始數據的哈希值,並以單一訊息的形式傳送原始數據和哈希值。 接收者會重新計算所接收訊息上的哈希值,並檢查計算的 HMAC 是否符合傳輸的 HMAC。

如果原始和計算的哈希值相符,則會驗證訊息。 如果它們不相符,則數據或哈希值已變更。 HMAC 提供安全性以防止竄改,因為必須知道秘密密鑰才能變更訊息,並重現正確的哈希值。

HMACSHA512 接受任何大小的索引鍵,併產生長度為512位的哈希序列。

建構函式

HMACSHA512()

使用隨機產生的金鑰,初始化 HMACSHA512 類別的新執行個體。

HMACSHA512(Byte[])

使用指定的金鑰資料,初始化 HMACSHA512 類別的新執行個體。

欄位

HashSizeInBits

HMAC SHA512 演算法所產生的哈希大小,以位為單位。

HashSizeInBytes

HMAC SHA512 演算法所產生的哈希大小,以位元組為單位。

HashSizeValue

代表計算出來之雜湊碼的大小,以位元為單位。

(繼承來源 HashAlgorithm)
HashValue

表示計算出來的雜湊碼的值。

(繼承來源 HashAlgorithm)
KeyValue

要使用於雜湊演算法的金鑰。

(繼承來源 KeyedHashAlgorithm)
State

表示雜湊計算的狀態。

(繼承來源 HashAlgorithm)

屬性

BlockSizeValue

取得或設定要使用於雜湊值的區塊大小。

(繼承來源 HMAC)
CanReuseTransform

取得值,表示目前的轉換是否可重複使用。

(繼承來源 HashAlgorithm)
CanTransformMultipleBlocks

在衍生類別中覆寫時,取得值以指出是否有多個區塊可被轉換。

(繼承來源 HashAlgorithm)
Hash

取得計算出來之雜湊碼的值。

(繼承來源 HashAlgorithm)
HashName

取得或設定用於雜湊的雜湊演算法名稱。

(繼承來源 HMAC)
HashSize

取得計算出的 HMAC 大小,以位元為單位。

HashSize

取得計算出來之雜湊碼的大小,以位元為單位。

(繼承來源 HashAlgorithm)
InputBlockSize

在衍生類別中覆寫時,取得輸入區塊的大小。

(繼承來源 HashAlgorithm)
Key

取得或設定要在 HMAC 計算中使用的索引鍵。

Key

取得或設定要在 HMAC 計算中使用的索引鍵。

(繼承來源 HMAC)
OutputBlockSize

在衍生類別中覆寫時,取得輸出區塊的大小。

(繼承來源 HashAlgorithm)
ProduceLegacyHmacValues
已淘汰.

為演算法的 HMACSHA512 .NET Framework 2.0 實作提供因應措施,這與 .NET Framework 2.0 Service Pack 1 實作不一致。

方法

Clear()

釋放 HashAlgorithm 類別所使用的所有資源。

(繼承來源 HashAlgorithm)
ComputeHash(Byte[])

計算指定位元組陣列的雜湊值。

(繼承來源 HashAlgorithm)
ComputeHash(Byte[], Int32, Int32)

計算所指定位元組陣列中指定區域的雜湊值。

(繼承來源 HashAlgorithm)
ComputeHash(Stream)

計算指定 Stream 物件的雜湊值。

(繼承來源 HashAlgorithm)
ComputeHashAsync(Stream, CancellationToken)

以非同步方式計算指定 Stream 物件的雜湊值。

(繼承來源 HashAlgorithm)
Dispose()

釋放 HashAlgorithm 類別目前的執行個體所使用的全部資源。

(繼承來源 HashAlgorithm)
Dispose(Boolean)

釋放 HMACSHA512 所使用的 Unmanaged 資源,並選擇性地釋放 Managed 資源。

Dispose(Boolean)

如果金鑰變更是合法的,則釋放 HMAC 類別所使用的 Unmanaged 資源,並選擇性釋放 Managed 資源。

(繼承來源 HMAC)
Equals(Object)

判斷指定的物件是否等於目前的物件。

(繼承來源 Object)
GetHashCode()

做為預設雜湊函式。

(繼承來源 Object)
GetType()

取得目前執行個體的 Type

(繼承來源 Object)
HashCore(Byte[], Int32, Int32)

將寫入物件的資料路由傳送至 HMAC 演算法,以用來計算 HMAC。

HashCore(Byte[], Int32, Int32)

於衍生類型中覆寫時,將寫入物件的資料路由傳送至用來計算 HMAC 值的 HMAC 演算法。

(繼承來源 HMAC)
HashCore(ReadOnlySpan<Byte>)

將寫入物件的資料路由傳送至 HMAC 演算法,以用來計算 HMAC。

HashCore(ReadOnlySpan<Byte>)

將寫入物件的資料路由傳送至 HMAC 演算法,以用來計算 HMAC。

(繼承來源 HMAC)
HashData(Byte[], Byte[])

使用 SHA512 演演算法計算數據的 HMAC。

HashData(Byte[], Stream)

使用 SHA512 演演算法計算數據流的 HMAC。

HashData(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>)

使用 SHA512 演演算法計算數據的 HMAC。

HashData(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>)

使用 SHA512 演演算法計算數據的 HMAC。

HashData(ReadOnlySpan<Byte>, Stream)

使用 SHA512 演演算法計算數據流的 HMAC。

HashData(ReadOnlySpan<Byte>, Stream, Span<Byte>)

使用 SHA512 演演算法計算數據流的 HMAC。

HashDataAsync(Byte[], Stream, CancellationToken)

使用 SHA512 演算法,以異步方式計算數據流的 HMAC。

HashDataAsync(ReadOnlyMemory<Byte>, Stream, CancellationToken)

使用 SHA512 演算法,以異步方式計算數據流的 HMAC。

HashDataAsync(ReadOnlyMemory<Byte>, Stream, Memory<Byte>, CancellationToken)

使用 SHA512 演算法,以異步方式計算數據流的 HMAC。

HashFinal()

在演算法處理最後一筆資料之後,完成 HMAC 計算。

HashFinal()

於衍生類型中覆寫時,在演算法處理最後一筆資料後,完成 HMAC 計算。

(繼承來源 HMAC)
Initialize()

將雜湊演算法重設為其初始狀態。

Initialize()

初始化 HMAC 預設實作的執行個體。

(繼承來源 HMAC)
MemberwiseClone()

建立目前 Object 的淺層複製。

(繼承來源 Object)
ToString()

傳回代表目前物件的字串。

(繼承來源 Object)
TransformBlock(Byte[], Int32, Int32, Byte[], Int32)

計算輸入位元組陣列中指定區域的雜湊值,並將指定的輸入位元組陣列區域複製到指定的輸出位元組陣列區域。

(繼承來源 HashAlgorithm)
TransformFinalBlock(Byte[], Int32, Int32)

計算所指定位元組陣列中指定區域的雜湊值。

(繼承來源 HashAlgorithm)
TryComputeHash(ReadOnlySpan<Byte>, Span<Byte>, Int32)

嘗試計算指定位元組陣列的雜湊值。

(繼承來源 HashAlgorithm)
TryHashData(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Span<Byte>, Int32)

嘗試使用 SHA512 演演算法計算數據的 HMAC。

TryHashFinal(Span<Byte>, Int32)

在 HMAC 演算法處理最後一筆資料之後,嘗試完成 HMAC 計算。

TryHashFinal(Span<Byte>, Int32)

在 HMAC 演算法處理最後一筆資料之後,嘗試完成 HMAC 計算。

(繼承來源 HMAC)

明確介面實作

IDisposable.Dispose()

釋放 HashAlgorithm 所使用的 Unmanaged 資源,並選擇性地釋放 Managed 資源。

(繼承來源 HashAlgorithm)

適用於

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