2.2.1.12.1.1 Licensing Preamble (LICENSE_PREAMBLE)

The LICENSE_PREAMBLE structure precedes every licensing packet sent on the wire.

0	1	2	3	4	5	6	7	8	9	1 0	1	2	3	4	5	6	7	8	9	2 0	1	2	3	4	5	6	7	8	9	3 0	1
bMsgType								flags								wMsgSize

bMsgType (1 byte): An 8-bit, unsigned integer. A type of the licensing packet. For more details about the different licensing packets, see [MS-RDPELE] section 2.2.2.

Sent by server:

Value	Meaning
LICENSE_REQUEST 0x01	Indicates a License Request PDU ([MS-RDPELE] section 2.2.2.1).
PLATFORM_CHALLENGE 0x02	Indicates a Platform Challenge PDU ([MS-RDPELE] section 2.2.2.4).
NEW_LICENSE 0x03	Indicates a New License PDU ([MS-RDPELE] section 2.2.2.7).
UPGRADE_LICENSE 0x04	Indicates an Upgrade License PDU ([MS-RDPELE] section 2.2.2.6).

Sent by client:

Value	Meaning
LICENSE_INFO 0x12	Indicates a License Information PDU ([MS-RDPELE] section 2.2.2.3).
NEW_LICENSE_REQUEST 0x13	Indicates a New License Request PDU ([MS-RDPELE] section 2.2.2.2).
PLATFORM_CHALLENGE_RESPONSE 0x15	Indicates a Platform Challenge Response PDU ([MS-RDPELE] section 2.2.2.5).

Sent by either client or server:

Value	Meaning
ERROR_ALERT 0xFF	Indicates a Licensing Error Message PDU (section 2.2.1.12.1.3).

flags (1 byte): An 8-bit, unsigned integer. License preamble flags.

Value	Meaning
LicenseProtocolVersionMask 0x0F	The license protocol version. See the discussion which follows this table for more information.
EXTENDED_ERROR_MSG_SUPPORTED 0x80	Indicates that extended error information using the Licensing Error Message (section 2.2.1.12.1.3) is supported.

The LicenseProtocolVersionMask is a 4-bit value containing the supported license protocol version. The following are possible version values.

Value	Meaning
PREAMBLE_VERSION_2_0 0x2	RDP 4.0
PREAMBLE_VERSION_3_0 0x3	RDP 5.0, 5.1, 5.2, 6.0, 6.1, 7.0, 7.1, 8.0, 8.1, 10.0, 10.1, 10.2, 10.3, 10.4, and 10.5

wMsgSize (2 bytes): An 16-bit, unsigned integer. The size in bytes of the licensing packet (including the size of the preamble).