WD_Encryption_API.txt

                          Reference Manual 
                                of 
                     Vendor Specific Extensions 
                                of 
                         WD My Passport drive

			Rev. C, 16.07.2014

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 * INFORMATIONS ARE PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 
 * WARRANTIES ARE DISCLAIMED. IN NO EVENT NO ONE THAN YOU WILL BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, LOSS OF DATA)
 * ARISING IN ANY WAY OUT OF THE USE OF INFORMATIONS IN THIS DOCUMENT
 -------------------------------------------------------------------------

 Informations provided herein are compiled from various information source
 and/or based on observation. They are not derived from an oficial vendor
 documentation nor they has been verified by vendor. They has been tested on
 very limited test of devices. 

 !!!!!!!!!!!!!!!!!!!!!!!!!!!!! DANGER !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 Use of command described here may cause irrepairable lost of drive content. 
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!! DANGER !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 =========================================================================

1. *** VENDOR SPECIFIC SCSI COMMANDS

 =========================================================================

1.1 ENCRYPTION STATUS(10) command

The ENCRYPTION STATUS(10) command (see table 1) requests that information
regarding current security/encryption status of server device to be sent
to an application client. For the format of returned data see table 2.

Table 1 - ENCRYPTION STATUS(10) command
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                  OPERATION CODE (C0h)                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                OPERATION SUBCODE (45h)                        |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   2  |                                                               |
+------+-------                 Reserved                         ------+
|   6  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   7  | (MSB)                                                         |
+------+-------            ALLOCATION LENGTH                     ------+
|   8  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   9  |                        CONTROL                                |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

ALLOCATION LENGTH field

The Allocation length should be at least 16B, so that NUMBER OF CIPHERS 
is returned.

Table 2 - ENCRYPTION STATUS data format 
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                    SIGNATURE (45h)                            |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                                                               |
+------+-------                 Reserved                         ------+
|   2  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   3  |                    SECURITY STATUS                            |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   4  |                   CURRENT CIPHER ID                           |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   5  |                        Reserved                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   6  | (MSB)                                                         |
+------+-------              PASSWORD LENGTH                     ------+
|   7  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   8  |                                                               |
+------+-------            KEY RESET ENABLER                     ------+
|  11  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|  12  |                                                               |
+------+-------                 Reserved                         ------+
|  14  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|  15  |                    NUMBER OF CIPHERS                          |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|  16  |                        CIPHER 0                               |
+------+-------                                                  ------+
| 15+n |                        CIPHER n                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

SIGNATURE field

The SIGNATURE field is 45h all the times

SECURITY STATUS field

The SECURITY STATUS field report the current security status of server
device. The values are described in table 3.

Table 3 - SECURITY STATUS
+--------+-----------------------------------------------------------------+
| Status | Description                                                     |
+--------+-----------------------------------------------------------------+
|    0   | Device encryption key is not protected by user supplied password|
+--------+-----------------------------------------------------------------+
|    1   | Device encryption key is locked                                 |
+--------+-----------------------------------------------------------------+
|    2   | Device encryption key is user password protected and unlocked   |
+--------+-----------------------------------------------------------------+
|    6   | As [1] but no more unlock attempts are allowed                  |
+--------+-----------------------------------------------------------------+
|    7   | Device has no encryption key                                    |
+--------+-----------------------------------------------------------------+
| Status 0 mean that data are still encrypted on the drive, but encryption |
|   key is scrambled by a vendor specific default password. Password needs |
|   not to be supplied by application to access the drive on power on      |
| Device with password set start in mode 1, see UNLOCK ENCRYPTION command  |
|   for more information                                                   |
| Device with no encryption key should not be seen in production           |
+--------------------------------------------------------------------------+

CURRENT CIPHER ID

The CURRENT CIPHER ID field report the encryption alghoritm used on device.
Possible values are described in table 4.

Table 4 - CIPHER ID
+--------+-----------------------------------------------------------------+
|   ID   | Cipher Alghoritm                                                |
+--------+-----------------------------------------------------------------+
|   00h  | No encryption                                                   |
+--------+-----------------------------------------------------------------+
|   10h  | AES 128 ECB                                                     |
+--------+-----------------------------------------------------------------+
|   12h  | AES 128 CBC                                                     |
+--------+-----------------------------------------------------------------+
|   18h  | AES 128 XTS                                                     |
+--------+-----------------------------------------------------------------+
|   20h  | AES 256 ECB                                                     |
+--------+-----------------------------------------------------------------+
|   22h  | AES 256 CBC                                                     |
+--------+-----------------------------------------------------------------+
|   28h  | AES 256 XTS                                                     |
+--------+-----------------------------------------------------------------+
|   30h  | Full Disc Encryption                                            |
+--------+-----------------------------------------------------------------+

PASSWORD LENGTH field

The PASSWORD LENGTH field contain the length of password used on drive.
Password is binary blob of specified size. The size is expressed in bytes. 
It is 16B for AES 128 cipher suite and 32B for AES 256 cipher suite and FDE.

KEY RESET ENABLER field

The KEY RESET ENABLER field is four byte code required for subsequent
RESET DATA ENCRYPTION KEY command. Such command needs to be called
immediatelly as code changes with any command issued on device.

NUMBER OF CIPHERS and CIPHER n

The NUMBER OF CIPHERS and CIPHER n fields describe th elist of encryption
alghoritms supported by the device. For description of CIPHER i field see
table 4.

 =========================================================================

1.2 UNLOCK ENCRYPTION(10) command

The UNLOCK ENCRYPTION(10) command (see table 5) provides a means for an
application to supply the password that unlock the drive encryption key. 

The security status needs to be 1 (LOCKED, see table 3) otherwise command
will be terminated with CHECK CONDITION status, with sense key set to 
ILLEGAL REQUEST, and additional sense code set to 74h/81h (if security 
status 0, 2 or 7) or 74h/80h (if security status 06h).

If security status is 1, the supplied password is used to unlock internal
encryption key. For the format of command parameter block see table 6.

If unlock attempt is unsuccesfull, command will be terminated with 
CHECK CONDITION status, with sense key set to ILLEGAL REQUEST, and 
additional sense code set to AUTHENTICATION FAILED (74h/40h).  Number of
unsuccesfull attempt is incremented. 

If number of unsucesfull attempts exceed an internal limit, secure status 
become 6 and no further unlock attempts are allowed.  Either power off/on
transition or RESET DATA ENCRYPTION KEY is required to solve it.

On succesfull unlock the security status of device become 2 (UNLOCKED) .

Unless unlocked, access to most common commands including reading and
writting a sector of drive or format is not allowed. Those commands are
terminated with CHECK CONDITION status, with sense key set to DATA PROTECT,
and additional sense code set to LOGICAL UNIT ACCESS NOT AUTHORIZED 
(74h/71h). 

Table 5 - UNLOCK ENCRYPTION(10) command
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                  OPERATION CODE (C1h)                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                OPERATION SUBCODE (E1h)                        |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   2  |                                                               |
+------+-------                 Reserved                         ------+
|   6  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   7  | (MSB)                                                         |
+------+-------          PARAMETER LIST LENGTH                   ------+
|   8  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   9  |                        CONTROL                                |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

PARAMETER LIST LENGTH field

The Parameter list length need to follow exact size of expected parameter
block size of command will be terminated with CHECK CONDITION status, 
with sense key set to ILLEGAL REQUEST, and  additional sense code set to 
INVALID FIELD IN CDB (24h/00h).

Table 6 - UNLOCK ENCRYPTION data format 
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                    SIGNATURE (45h)                            |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                                                               |
+------+-------                 Reserved                         ------+
|   5  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   6  | (MSB)                                                         |
+------+-------              PASSWORD LENGTH                     ------+
|   7  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   8  |                                                               |
+------+-------                  PASSWORD                        ------+
| 8+L  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

SIGNATURE field

The SIGNATURE field is 45h all the times

PASSWORD LENGTH and PASSWORD fields

The PASSWORD LENGTH field contain the length of password used on drive.
The size is expressed in bytes. PASSWORD field is binary blob of specified
size. The size is expressed in bytes. 

The size of password is not user selectable it must be exactly the same as
specified by the drive in PASSWORD LENGTH field of response to 
ENCRYPTION STATUS command or command will be terminated with CHECK CONDITION 
status, with sense key set to ILLEGAL REQUEST, and  additional sense code
set to INVALID FIELD IN PARAMETER LIST (26h/00h).

 =========================================================================

1.3 CHANGE ENCRYPTION PASSPHRASE(10) command

The CHANGE ENCRYPTION PASSPHRASE(10) command (see table 7) provides 
a means for an application to change the password that unlock the drive 
encryption key. It can be used to enable and disable password security as
well.

"Disabled password security" mean that security status is 0 and password 
needs not to be supplied by application to access the drive. See table 3 for
more information.

The security status needs to be 2 (UNLOCKED, see table 3) for password
change and disable security operations and 0 (NotProtected) for enable 
security operation. If drive is not in expected state the command
will be terminated with CHECK CONDITION status, with sense key set to 
ILLEGAL REQUEST, and additional sense code set to 74h/81h (if security 
status 0, 2 or 7) or 74h/80h (if security status 06h).

For password change and disable security operations the old password is
required. If password is not correct, command will be terminated with 
CHECK CONDITION status, with sense key set to ILLEGAL REQUEST, and 
additional sense code set to AUTHENTICATION FAILED (74h/40h).  Number of
unsuccesfull attempt is incremented. 

If number of unsucesfull attempts exceed an internal limit, drive's secure 
status become 6 and no further change encryption passphrase nor unlock attempts 
are allowed.  Either power off/on transition or RESET DATA ENCRYPTION KEY 
is required to solve it.

For the format of command parameter block see table 8.

If old password is correct or "enable security" operation is requested, the
new password si installed in the drive. Security status of device become 
2 (UNLOCKED) for password change and enable security operations or 
0 (NotProtected) for disable security operation.

Table 7 - CHANGE ENCRYPTION PASSPHRASE(10) command
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                  OPERATION CODE (C1h)                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                OPERATION SUBCODE (E2h)                        |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   2  |                                                               |
+------+-------                 Reserved                         ------+
|   6  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   7  | (MSB)                                                         |
+------+-------          PARAMETER LIST LENGTH                   ------+
|   8  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   9  |                        CONTROL                                |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

PARAMETER LIST LENGTH field

The Parameter list length need to follow exact size of expected parameter
block size of command will be terminated with CHECK CONDITION status, 
with sense key set to ILLEGAL REQUEST, and  additional sense code set to 
INVALID FIELD IN CDB (24h/00h).

Table 8 - CHANGE ENCRYPTION PASSPHRASE data format 
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                    SIGNATURE (45h)                            |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                                                               |
+------+-------                 Reserved                         ------+
|   2  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   3  |        Reserved       | NEWDEF|        Reserved       | OLDDEF|
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   4  |                                                               |
+------+-------                 Reserved                         ------+
|   5  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   6  | (MSB)                                                         |
+------+-------              PASSWORD LENGTH                     ------+
|   7  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   8  |                                                               |
+------+-------                OLD PASSWORD                      ------+
| 7+L  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
| 8+L  |                                                               |
+------+-------                NEW PASSWORD                      ------+
| 7+2*L|                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

SIGNATURE field

The SIGNATURE field is 45h all the times

OLDDEF bit

The OLDDEF bit is set to 1 then OLD PASSWORD content is ignored and vendor
specific default password is used instead. It is used for "enable security"
operation.

NEWDEF bit

The NEWDEF bit is set to 1 then NEW PASSWORD content is ignored and vendor
specific default password is used instead. It is used for "disable security"
operation. Both NEWDEF and OLDDEF must not be set to 1 at the same time or 
command will be terminated with CHECK CONDITION status, with sense key set 
to ILLEGAL REQUEST, and additional sense code set to 
INVALID FIELD IN PARAMETER LIST (26h/00h).

PASSWORD LENGTH, OLD PASSWORD and NEW PASSWORD fields

The PASSWORD LENGTH field contain the length of password used on drive.
The size is expressed in bytes. OLD PASSWORD and NEW PASSWORD fields 
are binary blob of specified size. The size is expressed in bytes. 

The size of password is not user selectable it must be exactly the same as
specified by the drive in PASSWORD LENGTH field of response to 
ENCRYPTION STATUS command or command will be terminated with CHECK CONDITION 
status, with sense key set to ILLEGAL REQUEST, and  additional sense code
set to INVALID FIELD IN PARAMETER LIST (26h/00h).

 =========================================================================

1.4 RESET DATA ENCRYPTION KEY(10) command

The RESET DATA ENCRYPTION KEY(10) command (see table 9) enforce drive to
generate new data encryption key. As old key become lost, the encrypted data
stored on medium are not changed but can't be decrypted anymore.

Command can be called in any security state. It's intended to solve "lost
user password" condition or change internal encryption alghoritm or just to
quickly make all data on medium inaccesible.

Reset Data Encryption Key command doesn't change data stored on the medium, 
but they can't be decrypted anymore as old encryption key become lost.

New Encryption key is scrambled by vendor specific password and not supplied
outside of the device, security state of device become 0 (NotProtected).

Reset Data Encryption Key command is protected against unintended invocation
by KEY RESET ENABLER field. The ENCRYPTION STATUS command needs to be called
just before RESET DATA ENCRYPTION KEY command to obtain valid code (see
table 2). If no valid code filled then command will be terminated with 
CHECK CONDITION status, with sense key set to ILLEGAL REQUEST, and additional
sense code set to INVALID FIELD IN CDB (24h/00h).

For the format of command parameter block see table 10.

Table 9 - RESET DATA ENCRYPTION KEY(10) command
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                  OPERATION CODE (C1h)                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                OPERATION SUBCODE (E3h)                        |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   2  |                                                               |
+------+-------            KEY RESET ENABLER                     ------+
|   5  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   6  |                        Reserved                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   7  | (MSB)                                                         |
+------+-------          PARAMETER LIST LENGTH                   ------+
|   8  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   9  |                        CONTROL                                |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

PARAMETER LIST LENGTH field

The Parameter list length need to follow exact size of expected parameter
block size of command will be terminated with CHECK CONDITION status, 
with sense key set to ILLEGAL REQUEST, and  additional sense code set to 
INVALID FIELD IN CDB (24h/00h).

Table 10 - RESET DATA ENCRYPTION KEY data format 
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                    SIGNATURE (45h)                            |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                                                               |
+------+-------                 Reserved                         ------+
|   2  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   3  |                        Reserved                       |COMBINE|
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   4  |                        CIPHER ID                              |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   5  |                        Reserved                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   6  | (MSB)                                                         |
+------+-------                KEY LENGTH                        ------+
|   7  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   8  |                                                               |
+------+-------                   KEY                            ------+
| 7+L  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

SIGNATURE field

The SIGNATURE field is 45h all the times

COMBINE bit

The meaning of COMBINE bit is not known. It's set to 0 for FDE Cipher, to 1
otherwise by WDUtils.

CIPHER ID field

The drive's data encryption alghoritm will be set to the one specified by ID. 
List of supported ciphers can be found in response to ENCRYPTION STATUS
command, see table 2 and table 4 for description.

KEY LENGTH and KEY fields

The KEY LENGTH field contain the length of KEY blob. The size is expressed in
bites (not bytes as in password length used in other commands). The role of
KEY in process of key reset is not known. It's set to (pseudo)random data by
WD utilities.

The size of data is not user selectable it must be same as the password length
of password of selected CIPHER ID. Otherwise command will be terminated with 
CHECK CONDITION status, with sense key set to ILLEGAL REQUEST, and additional
sense code set to INVALID FIELD IN PARAMETER LIST (26h/00h).

 =========================================================================

1.5 READ HANDY CAPACITY(10) command

The READ HANDY CAPACITY(10) command (see table 11) return the parameters of
drive's handy store. Handy store is data store independent from main
drive capacity. The applications may read and write data here according own
requirements. Stored data has no meaning for drive itself. Handy Store data 
can be read in any security state. It can be written in unlocked or not 
protected state only.

For the format of returned data see table 12.

Table 11 - READ HANDY CAPACITY(10) command
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                  OPERATION CODE (D5h)                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                                                               |
+------+-------                 Reserved                         ------+
|   8  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   9  |                        CONTROL                                |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

Table 12 - READ HANDY CAPACITY data format 
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  | (MSB)                                                         |
+------+-------            LAST HANDY BLOCK ADDRESS              ------+
|   3  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   4  | (MSB)                                                         |
+------+-------                BLOCK LENGTH                      ------+
|   7  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   8  |                                                               |
+------+-------                 Reserved                         ------+
|   9  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|  10  | (MSB)                                                         |
+------+-------            MAXIMUM TRANSFER LENGTH               ------+
|  11  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

LAST HANDY BLOCK ADDRESS field

The LAST HANDY BLOCK ADDRESS field contain the address of last addressable handy store block.

BLOCK LENGTH field

The BLOCK LENGTH field contain the size (in bytes) of a handy store block.

MAXIMUM TRANSFER LENGTH

The MAXIMUM TRANSFER LENGTH field contain the maximum number of blocks that
can be read/written at once.

 =========================================================================

1.6 READ HANDY STORE(10) command

The READ HANDY STORE(10) command (see table 13) request that device read the
specified handy store block and transfer them to the data-in buffer.

See READ HANDY CAPACITY command for more description of Handy Store

Table 13 - READ HANDY STORE(10) command
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                  OPERATION CODE (D8h)                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                        Reserved                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   2  | (MSB)                                                         |
+------+-------         HANDY STORE BLOCK ADDRESS                ------+
|   5  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   6  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   7  |  (MSB)                                                        |
+------+-------             TRANSFER LENGTH                      ------+
|   8  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   9  |                        CONTROL                                |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

HANDY STORE BLOCK ADDRESS field

The HANDY STORE BLOCK ADDRESS field specifies first handy store block
accesed by this command.

TRANSFER LENGTH field

The TRANSFER LENGTH field specifies number of contiguous handy store blocks
of data that shall be read and transferred to the data-in buffer, starting
with the handy store block specified by HANDY STORE BLOCK ADDRESS field.

 =========================================================================

1.7 WRITE HANDY STORE(10) command

The WRITE HANDY STORE(10) command (see table 14) request that device
transfer the specified handy store block(s) from the data-out buffer and
write them.

See WRITE HANDY CAPACITY command for more description of Handy Store

Table 14 - WRITE HANDY STORE(10) command
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |                  OPERATION CODE (DAh)                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                        Reserved                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   2  | (MSB)                                                         |
+------+-------         HANDY STORE BLOCK ADDRESS                ------+
|   5  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   6  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   7  |  (MSB)                                                        |
+------+-------             TRANSFER LENGTH                      ------+
|   8  |                                                         (LSB) |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   9  |                        CONTROL                                |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

HANDY STORE BLOCK ADDRESS field

The HANDY STORE BLOCK ADDRESS field specifies first handy store block
accesed by this command.

TRANSFER LENGTH field

The TRANSFER LENGTH field specifies number of contiguous handy store blocks
of data that shall be transferred from data-out buffer and written, starting
with the handy store block specified by HANDY STORE BLOCK ADDRESS field.

 =========================================================================

2. *** VENDOR SPECIFIC MODE PAGES

 =========================================================================

2.1 Device Configuration Page (20h)

The Device Configuration Page for MODE SENSE/MODE SELECT defines device
configuration parameters.

Table 15 - Device Configuration Page (20h)
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |   PS |Reserved|              PAGE CODE (20h)                  |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                      PAGE LENGTH (06h)                        |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   2  |                       SIGNATURE (30h)                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   3  |                           Reserved                            |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   4  | DisAP |                Reserved               | DisCD | DisSES|
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   5  |                   Reserved                    | 2TBL  | DisWL |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   6  |                                                               |
+------+-------                 Reserved                         ------+
|   7  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

PS (Parameter Savable) bit

The returned Parameter Savable (PS) bit of 1 indicates that page 01h
parameter data is savable.

DisAP (Disable AP), DisWL (Disable White List) bits

The meaning of Disable AP and Disable White List is unknown

DisCD (Disable CDROM), DisSES (Disable SES) bits

Setting appropriate bits to 1 disable emulated CDROM device and/or SES
device.

2TBL (Two TB Limit)

Setting the bit to 1 limit reported drive capacity to 2TB maximum.

 =========================================================================

2.2 Operations Page (21h)

The Operations Page for MODE SENSE/MODE SELECT defines device operation 
parameters.

Table 16 - Operations Page (21h)
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|B \ b |   7   |   6   |   5   |   4   |   3   |   2   |   1   |   0   |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0  |   PS |Reserved|              PAGE CODE (21h)                  |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   1  |                      PAGE LENGTH (0Ah)                        |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   2  |                       SIGNATURE (30h)                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   3  |                           Reserved                            |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   4  |                   Reserved                   |LOOSESB2|ESATA15|
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   5  |                   Reserved                    |CDMValid|ENCDEJ|
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   6  |                                                               |
+------+-------                 Reserved                         ------+
|   7  |                                                               |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   8  |                       POWER LED BRITE                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|   9  |                       BACKLIGHT BRITE                         |
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|  10  |                      Reserved                         | INVLCD|
+------+-------+-------+-------+-------+-------+-------+-------+-------+
|  11  |                           Reserved                            |
+------+-------+-------+-------+-------+-------+-------+-------+-------+

PS (Parameter Savable) bit

The returned Parameter Savable (PS) bit of 1 indicates that page 01h
parameter data is savable.

LOOSESB2 (Loose SB2) bit

The meaning of Loose SB2 bit is unknown. It seems to be related to 
Fibre Channel - Single-Byte Command Code Sets Mapping Protocol - 2. 
(FC-SB-2)

ESATA15 (eSATA15) bit

The meaning of eSATA15 bit is unknown. It may be related to speed on eSATA 
port (150MBps)

CDMValid (CD Media Valid), ENCDEJ (Enable CD Eject) bits

The meaning of both of CD Media Valid and Enable CD Eject bits is unknown. 

POWER LED BRITE and BACKLIGHT BRITE values

The POWER LED BRITE and BACKLIGHT BRITE values control the brigthness of
power LED and LCD display backlight.

INVLCD (Inverted LCD) bit

The Inverted LCD bit turn LCD display to be negative (white on black).

 =========================================================================

2.3 Return All Pages Page (3Fh)

Note that standard  MODE SENSE Return All Pages command seems to have
off-by-one bug in some firmware versions. It report +1 size on list of
returned pages, so the latest reported page is random number. It doesn't
affect common drive operations in any way.

 =========================================================================

3. *** WD UTILITIES specific API (software)

 =========================================================================

The drive itself use password in the form of binary blob of fixed length
(16B for AES 128 ciphers, 32B for AES 256 ciphers and FDE). It's necesarry to
transform user's text input into that form. Such transform  needs to be
consistent accross utilities or resulting password blob will not be same and
unlock operation will fail. Current WD Utilities use salted sha256 hash to 
compute password blob from user input for AES 256 and FDE. AES 128 drives
are unsupported by current version of WD Utilities, so WD standard alghoritm
is not known for AES 128 suite.

All string operations (e.g. user input and hash) are done in UCS-2
(little-endian) encoding.

The pseudo code of alghoritm used in WD Utilities:

1. STR = CONCAT(SALT, UPW)
2. FOR i=1 TO i==ITERATION_COUNT DO STR = sha256Digest(STR)
3. RETURN (STR)

Where UPW is password as entered by user
SALT is salt prepended to such password for the purpose of digest
calculation
ITERATION_COUNT is the number of times the sha256Digest is applied to string

On exit STR contain password blob used for password operations on drive

Based on exact version and platform of WD Utilities, the SALT and ITERATION_COUNT
are either hardcoded in the code or stored in Security Block (drive's Handy Store
block 1). In the first case, the SALT of "WDC." is used and ITERATION COUNT
is 1000. In the second case, stored data are used for password blob
calculation. Vendor specific READ HANDY STORE(10) command should be used to 
read Security Block from drive. Hardcoded default Salt and Iteration Count will
be used if no Security Block foun on drive.

Even if stored SALT and ITERATION COUNT are honored by WD
utilities for the purpose of password blob calculation, they are rewritten
to defaults on first password change.

3.1 Security Block (drive's Handy Store block 1)

For the description of format of Security Block (drive's Handy Store block 1)
see table 17.

Table 17 - Security Block (Handy Store block 1)
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
| B     |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0   |                                                               |
+-------+-------             SIGNATURE (00h 01h 'W' 'D')          ------+
|   3   |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|       |                                                               |
+  4-7  +-------                 Reserved                         ------+
|       |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|       | (MSB)                                                         |
+  8-12 +-------                ITERATION COUNT                   ------+
|       |                                                          (LSB)|
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|       |                                                               |
+ 12-19 +-------                 SALT                             ------+
|       |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|       |                                                               |
+ 20-23 +-------                 Reserved                         ------+
|       |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|       |                                                               |
+ 24-225+-------                 HINT                             ------+
|       |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|       |                                                               |
+226-510+-------                 Reserved                         ------+
|       |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|  511  |                        CHECKSUM                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+

ITERATION COUNT field
The Interation Count field hold the number of digest operation applied on
salted user password string.

SALT and HINTS fields

The SALT and HINTS fields are UCS-2 little endian encoded strings. The first
one is uset as salt in process of password blob calculation. The second one
is just hint for the user to help him to enter password. Such arbitrary string has
no meaning for drive nor WD utilities beyond it can be displayed to user.

CHECKSUM field

The CHECKSUM field is used to verify the validity of the block. Sum of all
bytes in the block needs to be zero or block is considered invalid. Note
that it seems that some version of WD utilities count first byte of sector
twice as accident. As it is 0x00 it doesn't broke the result

NOTE 1: Hardware is not tied to alghoritm used by WD Utilities nor the
content of Handy Store Block 1 (Security Block). It's possible to implement
different alghoritm and maintain the drive using it. Of course, vendor's WD
utilities will not be able to maintain such disc at the same time.

NOTE 2: Alghoritm described above is used on drives set to AES 256 suite of
ciphers and for FDE. AES 128 suite is not supported by current WD utilities, 
thus there is no "standard vendor alghoritm" used to calculate password blob
known for such drives.

 =========================================================================

3.2 User Block (drive's Handy Store block 2)

Independent device label can be set and is recognized by WD Utilities in User
Block (Handy Store Block 2). For format of such block see table 18. Vendor
specific READ HANDY STORE(10) command should be used to read User Block from drive. 

Table 18 - User Block (Handy Store block 2)
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
| B     |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|   0   |                                                               |
+-------+-------             SIGNATURE (00h 02h 'W' 'D')          ------+
|   3   |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|       |                                                               |
+  4-7  +-------                 Reserved                         ------+
|       |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|       |                                                               |
+  8-71 +-------                 LABEL                            ------+
|       |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|       |                                                               |
+ 72-510+-------                 Reserved                         ------+
|       |                                                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+
|  511  |                        CHECKSUM                               |
+-------+-------+-------+-------+-------+-------+-------+-------+-------+

LABEL field

The LABEL field is UCS-2 little endian encoded strings. It is used as device label.

CHECKSUM field

See table 17 for description.