3.1.4.2.1.1.1 rgbIn Input Buffer
The rgbIn parameter input buffer can contain multiple extended buffers in a single input buffer. Each of the extended buffers contains an RPC_HEADER_EXT structure, as specified in section 2.2.2.1, followed by Payload data. A client MUST NOT send multiple extended buffers in the input buffer, if the server does not indicate it supports extended buffer packing through the AUX_SERVER_CAPABILITIES auxiliary buffer, as specified in section 2.2.2.2.19, returned in the rgbAuxOut parameter of the EcDoConnectEx method, as specified in section 3.1.4.1.1.1.2.
All RPC_HEADER_EXT structures in the input buffer except for the last MUST NOT contain the Last flag in the Flags field of the RPC_HEADER_EXT structure. The last RPC_HEADER_EXT structure in the input buffer MUST contain the Last flag in its Flags field.
If the Compressed flag is present in the Flags field of the RPC_HEADER_EXT structure, the payload data MUST be compressed by the client and MUST be uncompressed by the server before it can be interpreted. For details about the compression algorithm, see section 3.1.4.1.1.2.
If the XorMagic flag is present in the Flags field of the RPC_HEADER_EXT structure, the payload data MUST be obfuscated by the client and MUST be reverted by the server before it can be interpreted. For details about the obfuscation algorithm, see section 3.1.4.1.1.3.
If both the Compressed and XorMagic flags are present in the Flags field of the RPC_HEADER_EXT structure the payload data MUST first be compressed and then obfuscated by the client, and then MUST first be reverted and then uncompressed by the server before it can be interpreted.
The payload data is ROP request information that can be passed from the client to the server. For details about how to interpret this data, see [MS-OXCROPS].