TryDecrypt Method

TryDecrypt(ReadOnlyMemory<Byte>, out Memory<Byte>)

Try to decrypt the data using the given key. If the key is correct, this will set the return true and return the plaintext in the out argument (decrypted and decompressed).

C#

public bool TryDecrypt(ReadOnlyMemory<byte> largeBlobKey, out Memory<byte> plaintext)

Parameters

Type	Name	Description
System.ReadOnlyMemory<System.Byte>	largeBlobKey	The key to use to decrypt.
System.Memory<System.Byte>	plaintext	An output argument. A new object containing the plaintext if the decryption succeeds, or an empty Memory object otherwise.

Returns

System.Boolean

A boolean, true if the data is successfully decrypted using the given key, and false otherwise.

Remarks

Because the data is encrypted using AES-GCD, the ciphertext contains both the encrypted data and an "authentication tag". While any key will be able to decrypt the data and produce a result (some result), only the correct key will be able to authenticate the tag. Hence, this method will be able to determine whether the key provided was the correct key and the decrypted data is the correct data.

If the method is able to decrypt using the key, it will then decompress the decrypted data.

When reading a Large Blob Array, you will likely obtain the large blob data from the YubiKey, resulting in a SerializedLargeBlobArray object. At that point, each of the entries contain only the encrypted data. You will then obtain the LargeBlobKey from the target credential, and use it to try to decrypt the data of each entry in the Large Blob Array.

Note that the plaintext returned is a Memory object, not a ReadOnlyMemory object. This is so you can overwrite it for security reasons if you want.