IOCTL_AACS_GET_CHALLENGE_KEY IOCTL

Description

Queries the logical unit for the device's challenge key. The challenge key consists of a point on an elliptic curve and its associated signature.

Parameters

Major code

Input buffer

The buffer at Irp->AssociatedIrp.SystemBuffer contains a value of type DVD_SESSION_ID that specifies an Authentication Grant Identifier (AGID). The AGID identifies the secure session.

Input buffer length

Length of a DVD_SESSION_ID.

Output buffer

The buffer at Irp->AssociatedIrp.SystemBuffer contains the drive challenge key with a format of AACS_CHALLENGE_KEY.

Output buffer length

Length of an AACS_CHALLENGE_KEY.

Input/output buffer

Input/output buffer length

Status block

The Information field is set to the number of bytes transferred. The Status field is set to STATUS_SUCCESS or possibly STATUS_INSUFFICIENT_RESOURCES.

Remarks

The IOCTL_AACS_GET_CHALLENGE_KEY request corresponds to the step in the Advanced Access Content System (AACS) authentication algorithm (AACS-Auth) in which the drive provides the host with a point on the curve. For a complete description of AACS-Auth, see the Advanced Access Content System, Introduction and Common Cryptographic Elements specification that is published by Advanced Access Content System Licensing Administrator (AACS LA).