tr4st
Überflieger
Anmeldedatum: 16.04.2008
Beiträge: 486
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Verfasst am: 10.07.2008, 23:03 |
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Visual Basic: [code]Imports System
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
Public Class Rijndael
'
' Encrypts specified plaintext using Rijndael symmetric key algorithm
' and returns a base64-encoded result.
'
'
' Plaintext value to be encrypted.
'
'
' Passphrase from which a pseudo-random password will be derived. The
' derived password will be used to generate the encryption key.
' Passphrase can be any string. In this example we assume that this
' passphrase is an ASCII string.
'
'
' Salt value used along with passphrase to generate password. Salt can
' be any string. In this example we assume that salt is an ASCII string.
'
'
' Hash algorithm used to generate password. Allowed values are: "MD5" and
' "SHA1". SHA1 hashes are a bit slower, but more secure than MD5 hashes.
'
'
' Number of iterations used to generate password. One or two iterations
' should be enough.
'
'
' Initialization vector (or IV). This value is required to encrypt the
' first block of plaintext data. For RijndaelManaged class IV must be
' exactly 16 ASCII characters long.
'
'
' Size of encryption key in bits. Allowed values are: 128, 192, and 256.
' Longer keys are more secure than shorter keys.
'
'
' Encrypted value formatted as a base64-encoded string.
'
Public Shared Function Encrypt(ByVal plainText As String, _
ByVal passPhrase As String, _
ByVal saltValue As String, _
ByVal hashAlgorithm As String, _
ByVal passwordIterations As Integer, _
ByVal initVector As String, _
ByVal keySize As Integer) _
As String
' Convert strings into byte arrays.
' Let us assume that strings only contain ASCII codes.
' If strings include Unicode characters, use Unicode, UTF7, or UTF8
' encoding.
Dim initVectorBytes As Byte()
initVectorBytes = Encoding.ASCII.GetBytes(initVector)
Dim saltValueBytes As Byte()
saltValueBytes = Encoding.ASCII.GetBytes(saltValue)
' Convert our plaintext into a byte array.
' Let us assume that plaintext contains UTF8-encoded characters.
Dim plainTextBytes As Byte()
plainTextBytes = Encoding.UTF8.GetBytes(plainText)
' First, we must create a password, from which the key will be derived.
' This password will be generated from the specified passphrase and
' salt value. The password will be created using the specified hash
' algorithm. Password creation can be done in several iterations.
Dim password As PasswordDeriveBytes
password = New PasswordDeriveBytes(passPhrase, saltValueBytes, hashAlgorithm, passwordIterations)
' Use the password to generate pseudo-random bytes for the encryption
' key. Specify the size of the key in bytes (instead of bits).
Dim keyBytes As Byte()
keyBytes = password.GetBytes(keySize / 
' Create uninitialized Rijndael encryption object.
Dim symmetricKey As RijndaelManaged
symmetricKey = New RijndaelManaged()
' It is reasonable to set encryption mode to Cipher Block Chaining
' (CBC). Use default options for other symmetric key parameters.
symmetricKey.Mode = CipherMode.CBC
' Generate encryptor from the existing key bytes and initialization
' vector. Key size will be defined based on the number of the key
' bytes.
Dim encryptor As ICryptoTransform
encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes)
' Define memory stream which will be used to hold encrypted data.
Dim memoryStream As MemoryStream
memoryStream = New MemoryStream()
' Define cryptographic stream (always use Write mode for encryption).
Dim cryptoStream As CryptoStream
cryptoStream = New CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write)
' Start encrypting.
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length)
' Finish encrypting.
cryptoStream.FlushFinalBlock()
' Convert our encrypted data from a memory stream into a byte array.
Dim cipherTextBytes As Byte()
cipherTextBytes = memoryStream.ToArray()
' Close both streams.
memoryStream.Close()
cryptoStream.Close()
' Convert encrypted data into a base64-encoded string.
Dim cipherText As String
cipherText = Convert.ToBase64String(cipherTextBytes)
' Return encrypted string.
Encrypt = cipherText
End Function
'
' Decrypts specified ciphertext using Rijndael symmetric key algorithm.
'
'
' Base64-formatted ciphertext value.
'
'
' Passphrase from which a pseudo-random password will be derived. The
' derived password will be used to generate the encryption key.
' Passphrase can be any string. In this example we assume that this
' passphrase is an ASCII string.
'
'
' Salt value used along with passphrase to generate password. Salt can
' be any string. In this example we assume that salt is an ASCII string.
'
'
' Hash algorithm used to generate password. Allowed values are: "MD5" and
' "SHA1". SHA1 hashes are a bit slower, but more secure than MD5 hashes.
'
'
' Number of iterations used to generate password. One or two iterations
' should be enough.
'
'
' Initialization vector (or IV). This value is required to encrypt the
' first block of plaintext data. For RijndaelManaged class IV must be
' exactly 16 ASCII characters long.
'
'
' Size of encryption key in bits. Allowed values are: 128, 192, and 256.
' Longer keys are more secure than shorter keys.
'
'
' Decrypted string value.
'
'
' Most of the logic in this function is similar to the Encrypt
' logic. In order for decryption to work, all parameters of this function
' - except cipherText value - must match the corresponding parameters of
' the Encrypt function which was called to generate the
' ciphertext.
'
Public Shared Function Decrypt(ByVal cipherText As String, _
ByVal passPhrase As String, _
ByVal saltValue As String, _
ByVal hashAlgorithm As String, _
ByVal passwordIterations As Integer, _
ByVal initVector As String, _
ByVal keySize As Integer) As String
' Convert strings defining encryption key characteristics into byte
' arrays. Let us assume that strings only contain ASCII codes.
' If strings include Unicode characters, use Unicode, UTF7, or UTF8
' encoding.
Dim initVectorBytes As Byte()
initVectorBytes = Encoding.ASCII.GetBytes(initVector)
Dim saltValueBytes As Byte()
saltValueBytes = Encoding.ASCII.GetBytes(saltValue)
' Convert our ciphertext into a byte array.
Dim cipherTextBytes As Byte()
cipherTextBytes = Convert.FromBase64String(cipherText)
' First, we must create a password, from which the key will be
' derived. This password will be generated from the specified
' passphrase and salt value. The password will be created using
' the specified hash algorithm. Password creation can be done in
' several iterations.
Dim password As PasswordDeriveBytes
password = New PasswordDeriveBytes(passPhrase, saltValueBytes, hashAlgorithm, passwordIterations)
' Use the password to generate pseudo-random bytes for the encryption
' key. Specify the size of the key in bytes (instead of bits).
Dim keyBytes As Byte()
keyBytes = password.GetBytes(keySize /
' Create uninitialized Rijndael encryption object.
Dim symmetricKey As RijndaelManaged
symmetricKey = New RijndaelManaged()
' It is reasonable to set encryption mode to Cipher Block Chaining
' (CBC). Use default options for other symmetric key parameters.
symmetricKey.Mode = CipherMode.CBC
' Generate decryptor from the existing key bytes and initialization
' vector. Key size will be defined based on the number of the key
' bytes.
Dim decryptor As ICryptoTransform
decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes)
' Define memory stream which will be used to hold encrypted data.
Dim memoryStream As MemoryStream
memoryStream = New MemoryStream(cipherTextBytes)
' Define memory stream which will be used to hold encrypted data.
Dim cryptoStream As CryptoStream
cryptoStream = New CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read)
' Since at this point we don't know what the size of decrypted data
' will be, allocate the buffer long enough to hold ciphertext;
' plaintext is never longer than ciphertext.
Dim plainTextBytes As Byte()
ReDim plainTextBytes(cipherTextBytes.Length)
' Start decrypting.
Dim decryptedByteCount As Integer
decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length)
' Close both streams.
memoryStream.Close()
cryptoStream.Close()
' Convert decrypted data into a string.
' Let us assume that the original plaintext string was UTF8-encoded.
Dim plainText As String
plainText = Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount)
' Return decrypted string.
Decrypt = plainText
End Function
End Class[/code]
Da hast du eine Rijndael Klasse.
Anwendungsweise:
Visual Basic: [code]Dim passPhrase, saltValue, hashAlgorithm, initVector, usr, pwd As String
Dim passwordIterations, keySize As Integer
passPhrase = "X9o3j5!Y86iU!pPe8u7,5lY!" ' irgend ein String mit dem verschlüsselt wird
saltValue = "X9o3j6!Y86iU!pDe8u0,5lY!" ' irgend ein String mit dem verschlüsselt wird
hashAlgorithm = "SHA1" ' kann MD5 sein
passwordIterations = 2470 ' irgend ein Wert
initVector = "@1B2c3D4e3q9z4p7" ' muss ein 16bit String sein
keySize = 256 ' kann auch 192 oder 128 sein
Rijndael.Encrypt("Plaintext zum verschlüsseln", passPhrase, saltValue, hashAlgorithm, passwordIterations, initVector, keySize)
Rijndael.Decrypt("Hash zum entschlüsseln", passPhrase, saltValue, hashAlgorithm, passwordIterations, initVector, keySize)[/code] |
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n VB könnte ich es auch doch vb.NET ist ein wenig anders^^
