/// <summary>
/// Creates a key object for use with a symmetrical key encryption algorithm from a supplied key.
/// </summary>
/// <param name="algorithm">
/// The handle of an algorithm provider created with the <see cref="BCryptOpenAlgorithmProvider(string, string, BCryptOpenAlgorithmProviderFlags)"/> function. The algorithm specified when the provider was created must support symmetric key encryption.
/// </param>
/// <param name="secret">
/// A buffer that contains the key from which to create the key object. This is normally a hash of a password or some other reproducible data. If the data passed in exceeds the target key size, the data will be truncated and the excess will be ignored.
/// Note: We strongly recommended that applications pass in the exact number of bytes required by the target key.
/// </param>
/// <param name="keyObject">
/// A pointer to a buffer that receives the key object. The required size of this buffer can be obtained by calling the <see cref="BCryptGetProperty(SafeHandle, string, BCryptGetPropertyFlags)"/> function to get the BCRYPT_OBJECT_LENGTH property. This will provide the size of the key object for the specified algorithm.
/// This memory can only be freed after the returned key handle is destroyed.
/// If the value of this parameter is NULL, the memory for the key object is allocated and freed by this function.
/// </param>
/// <param name="flags">A set of flags that modify the behavior of this function. No flags are currently defined, so this parameter should be zero.</param>
/// <returns>A handle to the generated key.</returns>
public static SafeKeyHandle BCryptGenerateSymmetricKey(
SafeAlgorithmHandle algorithm,
byte[] secret,
byte[] keyObject = null,
BCryptGenerateSymmetricKeyFlags flags = BCryptGenerateSymmetricKeyFlags.None)
{
SafeKeyHandle hKey;
BCryptGenerateSymmetricKey(
algorithm,
out hKey,
keyObject,
keyObject?.Length ?? 0,
secret,
secret.Length,
flags).ThrowOnError();
return(hKey);
}
public static extern NTSTATUS BCryptGenerateSymmetricKey(
SafeAlgorithmHandle hAlgorithm,
out SafeKeyHandle phKey,
byte[] pbKeyObject,
int cbKeyObject,
byte[] pbSecret,
int cbSecret,
BCryptGenerateSymmetricKeyFlags flags = BCryptGenerateSymmetricKeyFlags.None);
