2.2.31.2 SRV_READ_HASH Request

The SRV_READ_HASH request is sent to the server by the client in an SMB2 IOCTL Request FSCTL_SRV_READ_HASH to retrieve data from the Content Information File associated with a specified file. The request is not valid for the SMB 2.0.2 dialect. It is set as the contents of the input data buffer. This packet consists of the following:


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

HashType

HashVersion

HashRetrievalType

Length

Offset

...

HashType (4 bytes): The hash type of the request indicates what the hash is used for. This field MUST be set to the following value:

Value

Meaning

SRV_HASH_TYPE_PEER_DIST

0x00000001

Indicates the hash is requested for branch caching as described in [MS-PCCRC].

HashVersion (4 bytes): The version number of the algorithm used to create the Content Information. This field MUST be set to one of the following values:

Value

Meaning

SRV_HASH_VER_1

0x00000001

Branch cache version 1.

SRV_HASH_VER_2

0x00000002

Branch cache version 2. This value is only applicable for the SMB 3.x dialect family.

HashRetrievalType (4 bytes): Indicates the nature of the Offset field. This field MUST be set to one of the following values:

Value

Meaning

SRV_HASH_RETRIEVE_HASH_BASED

0x00000001

The Offset field in the SRV_READ_HASH request is relative to the beginning of the Content Information File.

SRV_HASH_RETRIEVE_FILE_BASED

0x00000002

The Offset field in the SRV_READ_HASH request is relative to the beginning of the file indicated by the FileId field in the IOCTL request. This value is only applicable for the SMB 3.x dialect family.

Length (4 bytes): If HashRetrievalType is SRV_HASH_RETRIEVE_HASH_BASED, this value is the maximum length, in bytes, of the hash data to be returned in the SRV_READ_HASH response to the client. If HashRetrievalType is SRV_HASH_RETRIEVE_FILE_BASED, this value is the maximum length, in bytes, of the file data for which the hash information is to be retrieved and returned in the SRV_READ_HASH response to the client.

Offset (8 bytes): If HashRetrievalType is SRV_HASH_RETRIEVE_HASH_BASED, this value is the offset of the data to be retrieved, in bytes, from the beginning of the Content Information File. If HashRetrievalType is SRV_HASH_RETRIEVE_FILE_BASED, this value is the offset in the file for which the hash information is to be retrieved.

Show: