Entschlüsseln von Daten (HTML)
[ Dieser Artikel richtet sich an Windows 8.x- und Windows Phone 8.x-Entwickler, die Windows-Runtime-Apps schreiben. Wenn Sie für Windows 10 entwickeln, finden Sie weitere Informationen unter neueste Dokumentation]
Im folgenden Beispiel ist die Verwendung der Decrypt-Methode zum Entschlüsseln von Daten dargestellt.
function decryptDataBuffer(keyMaterial, stringToDecrypt, algNameString, keysize, ivBuffer) {
// Input arguments:
// keyMaterial.......Buffer that contains random key material (same as that used for encryption )
// stringToEncrypt...String that contains information to be decrypted
// algNameString.....String that contains the name of the symmetric algrorithm to use
// keysize...........Requested key size (same as that used for encryption )
// ivBuffer..........Buffer that contains the initialization buffer (must match the IV used for encryption)
var decryptedBuffer;
try {
// Convert the input string to binary.
var inputDataBuffer = Windows.Security.Cryptography.CryptographicBuffer.decodeFromBase64String(stringToDecrypt);
// Open the algorithm provider for the algorithm specified on input.
var algorithmProvider = Windows.Security.Cryptography.Core.SymmetricKeyAlgorithmProvider.openAlgorithm(algNameString);
if (keysize > algorithmProvider.supportedKeyLengths.max) {
// Handle error.
}
// Create a symmetric key.
var symmetricKey = algorithmProvider.createSymmetricKey(keyMaterial);
// Check the padding scheme and determine whether the data must be aligned.
if (algorithmProvider.padding != Windows.Security.Cryptography.Core.CryptographicPadding.block) {
// Data must be aligned by block size.
var i = inputDataBuffer.length % algorithmProvider.blockLength;
if (i > 0) {
// Handle error.
}
}
// Decrypt the input data.
decryptedBuffer = Windows.Security.Cryptography.Core.CryptographicEngine.decrypt(symmetricKey, inputDataBuffer, ivBuffer);
}
catch (e) {
// Handle error.
}
return decryptedBuffer;
}