PROTOCOLS
DeviceManager
Defined in fuchsia.hardware.block.encrypted/devicemanager.fidl
An interface to the zxcrypt driver, as bound to a single block device with a zxcrypt superblock. zxcrypt devices are encrypted, and before their plaintext contents can be accessed, they must be unsealed with a key. This protocol allows the caller to make requests to unseal the device (by providing the appropriate key) and to seal the device (rendering its contents inaccessible).
Format
Formats the device, destroying any previously-secured data. A new data
key is generated and wrapped with the provided key into key slot slot,
Returns ZX_ERR_BAD_STATE if the device is not currently sealed.
Returns ZX_OK on success.
Request
| Name | Type |
|---|---|
key |
vector<uint8>[256]
|
slot |
uint8
|
Response
| Name | Type |
|---|---|
status |
zx/status
|
Seal
Seals the device, causing any previously-created child zxcrypt Device to
be removed some time later. (Someday we'd like this to only return once
the unsealed child device is removed, but that's not straightforward today.)
Returns ZX_ERR_BAD_STATE if the device is already sealed.
Returns ZX_OK on success.
Request
<EMPTY>
Response
| Name | Type |
|---|---|
status |
zx/status
|
Shred
Shreds the device, permanently overwriting the keys that would allow
Unseal()ing the device again in the future. This call does not
impact the current sealed/unsealed state of the device -- if currently
unsealed, the device will remain in that state until Seal() is called
or the device is unbound.
Returns ZX_OK on success.
Returns other errors if operations on the underlying block device return errors.
Request
<EMPTY>
Response
| Name | Type |
|---|---|
status |
zx/status
|
Unseal
Attempts to unseal the device by using the provided master key to unwrap
the data key wrapped in the specified key slot. If the key provided was
the correct key for this slot, then the device node responding to this
protocol will create an unsealed zxcrypt device as a child of itself in
the device tree before returning success.
Returns ZX_ERR_INVALID_ARGS if slot is invalid.
Returns ZX_ERR_BAD_STATE and keeps the device open if the device is already unsealed.
Returns other errors if operations on the underlying block device return errors.
Returns ZX_OK on success.
Request
| Name | Type |
|---|---|
key |
vector<uint8>[256]
|
slot |
uint8
|
Response
| Name | Type |
|---|---|
status |
zx/status
|
STRUCTS
CONSTANTS
| Name | Value | Type | Description |
|---|---|---|---|
| MAX_KEY_SIZE |
256
|
uint32 |
We require simple layout to use the simple C bindings, and simple layout requires that we have non-maximal length bounds, so give some excessively large key length here so we can use the simple layout. |