HMACSHA512 コンストラクタ
オーバーロードの一覧
名前 | 説明 |
---|---|
HMACSHA512 () | ランダムに生成されたキーを指定して、HMACSHA512 クラスの新しいインスタンスを初期化します。 |
HMACSHA512 (Byte[]) | キー データを指定して、HMACSHA512 クラスの新しいインスタンスを初期化します。 |
HMACSHA512 コンストラクタ (Byte[])
アセンブリ: mscorlib (mscorlib.dll 内)
構文
例外
解説
HMACSHA512 は、SHA-512 ハッシュ関数から構築され、ハッシュ メッセージ認証コード (HMAC) として使用されるキー付きハッシュ アルゴリズムの一種です。HMAC プロセスでは、共有キーとメッセージ データを合成して、その結果にハッシュ関数を適用し、ハッシュ値と共有キーを再び合成した上で、もう一度ハッシュ関数を適用します。出力されるハッシュは 512 ビット長になります。
HMACSHA512 オブジェクトを使用してファイルをエンコードしたり、エンコード済みのファイルをデコードしたりする方法を次のコード例に示します。
using System; using System.IO; using System.Security.Cryptography; public class HMACSHA512example { // 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. public static void EncodeFile(byte[] key, String sourceFile, String destFile) { // Initialize the keyed hash object. HMACSHA512 myhmacsha512 = new HMACSHA512(key); FileStream inStream = new FileStream(sourceFile, FileMode.Open); FileStream outStream = new FileStream(destFile, FileMode.Create); // Compute the hash of the input file. 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 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); myhmacsha512.Clear(); // Close the streams inStream.Close(); outStream.Close(); return; } // end EncodeFile // Decrypt the encoded file and compare to original file. public static bool DecodeFile(byte[] key, String sourceFile) { // Initialize the keyed hash object. HMACSHA512 hmacsha512 = new HMACSHA512(key); // Create an array to hold the keyed hash value read from the file. byte[] storedHash = new byte[hmacsha512.HashSize/8]; // Create a FileStream for the source file. 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 = hmacsha512.ComputeHash(inStream); // compare the computed hash with the stored value for (int i =0; i < storedHash.Length; i++) { if (computedHash[i] != storedHash[i]) { Console.WriteLine("Hash values differ! Encoded file has been tampered with!"); return false; } } Console.WriteLine("Hash values agree -- no tampering occurred."); return true; } //end DecodeFile private const string usageText = "Usage: HMACSHA512 inputfile.txt encryptedfile.hsh\nYou must specify the two file names. Only the first file must exist.\n"; public static void Main(string[] Fileargs) { //If no file names are specified, write usage text. if (Fileargs.Length < 2) { 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. byte[] secretkey = new Byte[64]; //RNGCryptoServiceProvider is an implementation of a random number generator. RNGCryptoServiceProvider rng = new 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[0], Fileargs[1]); // Take the encoded file and decode DecodeFile(secretkey, Fileargs[1]); } catch (IOException e) { Console.WriteLine("Error: File not found",e); } } //end if-else } //end main } //end class
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 for ( int i = 0; i < storedHash->Length; i++ ) { if ( computedHash[ i ] != storedHash[ i ] ) { Console::WriteLine( "Hash values differ! Encoded file has been tampered with!" ); return false; } } 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
import System.*; import System.IO.*; import System.Security.Cryptography.*; public class HMACSHA512Example { // 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. public static void EncodeFile(ubyte key[], String sourceFile, String destFile) { // Initialize the keyed hash object. HMACSHA512 myhmacsha512 = new HMACSHA512(key); FileStream inStream = new FileStream(sourceFile, FileMode.Open); FileStream outStream = new FileStream(destFile, FileMode.Create); // Compute the hash of the input file. ubyte hashValue[] = myhmacsha512.ComputeHash(inStream); // Reset inStream to the beginning of the file. inStream.set_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 ubyte buffer[] = new ubyte[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. public static boolean DecodeFile(ubyte key[], String sourceFile) { // Initialize the keyed hash object. HMACSHA512 hmacsha512 = new HMACSHA512(key); // Create an array to hold the keyed hash value read from the file. ubyte storedHash[] = new ubyte[hmacsha512.get_HashSize() / 8]; // Create a FileStream for the source file. 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. ubyte computedHash[] = hmacsha512.ComputeHash(inStream); // compare the computed hash with the stored value for (int i = 0; i < storedHash.length; i++) { if (computedHash[i] != storedHash[i]) { Console.WriteLine("Hash values differ! Encoded file has been " + " tampered with!"); return false; } } Console.WriteLine("Hash values agree -- no tampering occurred."); return true; } //end DecodeFile private static String usageText = "Usage: HMACSHA512 inputfile.txt " + "encryptedfile.hsh\nYou must specify the two file names. Only the " + "first file must exist.\n"; public static void main(String[] fileargs) { //If no file names are specified, write usage text. if (fileargs.length < 2) { 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. ubyte secretKey[] = new ubyte[64]; // RNGCryptoServiceProvider is an implementation of a random // number generator. RNGCryptoServiceProvider rng = new 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[0], fileargs[1]); // Take the encoded file and decode DecodeFile(secretKey, fileargs[1]); } catch (IOException e) { Console.WriteLine("Error: File not found", e); } } //end if-else } //end main } //end class HMACSHA512Example
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。
参照
HMACSHA512 コンストラクタ ()
アセンブリ: mscorlib (mscorlib.dll 内)
構文
解説
HMACSHA512 は、SHA-512 ハッシュ関数から構築され、ハッシュ メッセージ認証コード (HMAC) として使用されるキー付きハッシュ アルゴリズムの一種です。HMAC プロセスでは、共有キーとメッセージ データを合成して、その結果にハッシュ関数を適用し、ハッシュ値と共有キーを再び合成した上で、もう一度ハッシュ関数を適用します。出力されるハッシュは 512 ビット長になります。
HMACSHA512 オブジェクトを使用してファイルをエンコードしたり、エンコード済みのファイルをデコードしたりする方法を次のコード例に示します。
using System; using System.IO; using System.Security.Cryptography; public class HMACSHA512example { // 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. public static void EncodeFile(byte[] key, String sourceFile, String destFile) { // Initialize the keyed hash object. HMACSHA512 myhmacsha512 = new HMACSHA512(key); FileStream inStream = new FileStream(sourceFile, FileMode.Open); FileStream outStream = new FileStream(destFile, FileMode.Create); // Compute the hash of the input file. 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 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); myhmacsha512.Clear(); // Close the streams inStream.Close(); outStream.Close(); return; } // end EncodeFile // Decrypt the encoded file and compare to original file. public static bool DecodeFile(byte[] key, String sourceFile) { // Initialize the keyed hash object. HMACSHA512 hmacsha512 = new HMACSHA512(key); // Create an array to hold the keyed hash value read from the file. byte[] storedHash = new byte[hmacsha512.HashSize/8]; // Create a FileStream for the source file. 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 = hmacsha512.ComputeHash(inStream); // compare the computed hash with the stored value for (int i =0; i < storedHash.Length; i++) { if (computedHash[i] != storedHash[i]) { Console.WriteLine("Hash values differ! Encoded file has been tampered with!"); return false; } } Console.WriteLine("Hash values agree -- no tampering occurred."); return true; } //end DecodeFile private const string usageText = "Usage: HMACSHA512 inputfile.txt encryptedfile.hsh\nYou must specify the two file names. Only the first file must exist.\n"; public static void Main(string[] Fileargs) { //If no file names are specified, write usage text. if (Fileargs.Length < 2) { 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. byte[] secretkey = new Byte[64]; //RNGCryptoServiceProvider is an implementation of a random number generator. RNGCryptoServiceProvider rng = new 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[0], Fileargs[1]); // Take the encoded file and decode DecodeFile(secretkey, Fileargs[1]); } catch (IOException e) { Console.WriteLine("Error: File not found",e); } } //end if-else } //end main } //end class
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 for ( int i = 0; i < storedHash->Length; i++ ) { if ( computedHash[ i ] != storedHash[ i ] ) { Console::WriteLine( "Hash values differ! Encoded file has been tampered with!" ); return false; } } 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
import System.*; import System.IO.*; import System.Security.Cryptography.*; public class HMACSHA512Example { // 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. public static void EncodeFile(ubyte key[], String sourceFile, String destFile) { // Initialize the keyed hash object. HMACSHA512 myhmacsha512 = new HMACSHA512(key); FileStream inStream = new FileStream(sourceFile, FileMode.Open); FileStream outStream = new FileStream(destFile, FileMode.Create); // Compute the hash of the input file. ubyte hashValue[] = myhmacsha512.ComputeHash(inStream); // Reset inStream to the beginning of the file. inStream.set_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 ubyte buffer[] = new ubyte[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. public static boolean DecodeFile(ubyte key[], String sourceFile) { // Initialize the keyed hash object. HMACSHA512 hmacsha512 = new HMACSHA512(key); // Create an array to hold the keyed hash value read from the file. ubyte storedHash[] = new ubyte[hmacsha512.get_HashSize() / 8]; // Create a FileStream for the source file. 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. ubyte computedHash[] = hmacsha512.ComputeHash(inStream); // compare the computed hash with the stored value for (int i = 0; i < storedHash.length; i++) { if (computedHash[i] != storedHash[i]) { Console.WriteLine("Hash values differ! Encoded file has been " + " tampered with!"); return false; } } Console.WriteLine("Hash values agree -- no tampering occurred."); return true; } //end DecodeFile private static String usageText = "Usage: HMACSHA512 inputfile.txt " + "encryptedfile.hsh\nYou must specify the two file names. Only the " + "first file must exist.\n"; public static void main(String[] fileargs) { //If no file names are specified, write usage text. if (fileargs.length < 2) { 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. ubyte secretKey[] = new ubyte[64]; // RNGCryptoServiceProvider is an implementation of a random // number generator. RNGCryptoServiceProvider rng = new 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[0], fileargs[1]); // Take the encoded file and decode DecodeFile(secretKey, fileargs[1]); } catch (IOException e) { Console.WriteLine("Error: File not found", e); } } //end if-else } //end main } //end class HMACSHA512Example
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。
参照
- HMACSHA512 コンストラクタのページへのリンク