YubiHSM 2 Communication
Users and applications communicate with the YubiHSM 2 through either HTTP and USB using the yubihsm-connector. See YubiHSM 2 Connector.
HTTP Access to YubiHSM
This kind of connection talks to yubihsm-connector over http(s), allowing remote access to a YubiHSM2, see YubiHSM 2 Connector.
In order to select this type of backend the connector URL should use the http or https scheme; for example, to use a local HTTP Connector use http://127.0.0.1:12345.
Note
HTTP is default configuration.
USB Access to YubiHSM
This kind of connection is a direct-access USB backend that talks directly with a YubiHSM device. The USB Connector is built into libyubihsm. This renders it unnecessary to run an additional component (i.e., the external Connector) at the cost of requiring exclusive access to a YubiHSM device.
To select this type of backend the connector URL should use the yhusb scheme. For example, to use a local device with serial number 123456 use yhusb://serial=123456.