AddCredBlobExtension Method
AddCredBlobExtension(byte[], AuthenticatorInfo)
Add the "credBlob" extension. Note that the credBlob extension is valid only for discoverable credentials.
public void AddCredBlobExtension(byte[] credBlobValue, AuthenticatorInfo authenticatorInfo)Parameters
| Type | Name | Description |
|---|---|---|
| byte[] | credBlobValue | The data to add as the "credBlob" extension. |
| AuthenticatorInfo | authenticatorInfo | The FIDO2 |
Exceptions
| Type | Condition |
|---|---|
| ArgumentNullException | The |
| ArgumentException | The YubiKey does not support this extension, or the value's length was invalid. |
Remarks
Because this extension is used more often, a dedicated method is
provided as a convenience. There is no need for the caller to
encode the credBlobValue. That is, this is essentially the
same as calling AddExtension, except this method will verify
the YubiKey supports the extension, verify the data length, use the
appropriate extensionString, and encode the value.
The caller supplies the AuthenticatorInfo for the YubiKey,
obtained by calling the GetInfoCommand or
providing the AuthenticatorInfo property.
This method will determine from the authenticatorInfo whether
the YubiKey supports this extension, and whether the data provided is
within the YubiKey's range for "credBlob". The standard specifies
that the maximum credBlob length is at least 32 bytes. The
AuthenticatorInfo contains the property
MaximumCredentialBlobLength, which is the length the YubiKey
supports. If the YubiKey does not support the "credBlob" extension,
or the data is too long, this method will throw an exception.
The caller supplies the un-encoded credBlobValue. This method
will encode it.
The credBlob data will be returned when the credential is used to get an assertion. When building the GetAssertion parameters, the caller must specify that the YubiKey return the credBlob. See RequestCredBlobExtension(). The assertion returned will contain the credBlob. The data will be returned in the AuthenticatorData and can be retrieved using GetCredBlobExtension()