src/cobalt/site/docs/reference/starboard/modules/4/drm.md

---
layout: doc
title: "Starboard Module Reference: drm.h"
---

Provides definitions that allow for DRM support, which are common between Player
and Decoder interfaces.

## Macros ##

### kSbDrmSystemInvalid ###

An invalid SbDrmSystem.

### kSbDrmTicketInvalid ###

A ticket for callback invocations initiated by the DRM system.

## Enums ##

### SbDrmKeyStatus ###

Status of a particular media key. [https://w3c.github.io/encrypted-media/#idl-def-MediaKeyStatus](https://w3c.github.io/encrypted-media/#idl-def-MediaKeyStatus)

#### Values ####

*   `kSbDrmKeyStatusUsable`
*   `kSbDrmKeyStatusExpired`
*   `kSbDrmKeyStatusReleased`
*   `kSbDrmKeyStatusRestricted`
*   `kSbDrmKeyStatusDownscaled`
*   `kSbDrmKeyStatusPending`
*   `kSbDrmKeyStatusError`

### SbDrmSessionRequestType ###

The type of the session request. [https://www.w3.org/TR/encrypted-media/#idl-def-mediakeymessagetype](https://www.w3.org/TR/encrypted-media/#idl-def-mediakeymessagetype)

#### Values ####

*   `kSbDrmSessionRequestTypeLicenseRequest`
*   `kSbDrmSessionRequestTypeLicenseRenewal`
*   `kSbDrmSessionRequestTypeLicenseRelease`
*   `kSbDrmSessionRequestTypeIndividualizationRequest`

### SbDrmStatus ###

The status of session related operations. Used by
`SbDrmSessionUpdateRequestFunc`, `SbDrmSessionUpdatedFunc`, and
`SbDrmServerCertificateUpdatedFunc` to indicate the status of the operation. [https://w3c.github.io/encrypted-media/#error-names](https://w3c.github.io/encrypted-media/#error-names)

#### Values ####

*   `kSbDrmStatusSuccess`
*   `kSbDrmStatusTypeError`
*   `kSbDrmStatusNotSupportedError`
*   `kSbDrmStatusInvalidStateError`
*   `kSbDrmStatusQuotaExceededError`
*   `kSbDrmStatusUnknownError`

    The following error can be used when the error status cannot be mapped to
    one of the above errors.

## Typedefs ##

### SbDrmSessionClosedFunc ###

A callback for signalling that a session has been closed by the SbDrmSystem

#### Definition ####

```
typedef void(* SbDrmSessionClosedFunc) (SbDrmSystem drm_system, void *context, const void *session_id, int session_id_size)
```

### SbDrmSessionKeyStatusesChangedFunc ###

A callback for notifications that the status of one or more keys in a session
has been changed. All keys of the session and their new status will be passed
along. Any keys not in the list is considered as deleted.

#### Definition ####

```
typedef void(* SbDrmSessionKeyStatusesChangedFunc) (SbDrmSystem drm_system, void *context, const void *session_id, int session_id_size, int number_of_keys, const SbDrmKeyId *key_ids, const SbDrmKeyStatus *key_statuses)
```

### SbDrmSessionUpdateRequestFunc ###

A callback that will receive generated session update request when requested
from a SbDrmSystem. `drm_system` will be the DRM system that
SbDrmGenerateSessionUpdateRequest() was called on. `context` will be the same
context that was passed into the call to SbDrmCreateSystem().`ticket` will be
the same ticket that was passed to SbDrmGenerateSessionUpdateRequest() or
`kSbDrmTicketInvalid` if the update request was generated by the DRM system.

`session_id` can be NULL if there was an error generating the request.

#### Definition ####

```
typedef void(* SbDrmSessionUpdateRequestFunc) (SbDrmSystem drm_system, void *context, int ticket, const void *session_id, int session_id_size, const void *content, int content_size, const char *url)
```

### SbDrmSessionUpdatedFunc ###

A callback for notifications that a session has been added, and subsequent
encrypted samples are actively ready to be decoded. `drm_system` will be the DRM
system that SbDrmUpdateSession() was called on. `context` will be the same
context passed into that call to SbDrmCreateSystem().

`ticket` will be the same ticket that was passed to
SbDrmUpdateSession().`succeeded` is whether the session was successfully updated
or not.

#### Definition ####

```
typedef void(* SbDrmSessionUpdatedFunc) (SbDrmSystem drm_system, void *context, int ticket, const void *session_id, int session_id_size, bool succeeded)
```

### SbDrmSystem ###

A handle to a DRM system which can be used with either an SbDecoder or a
SbPlayer.

#### Definition ####

```
typedef struct SbDrmSystemPrivate* SbDrmSystem
```

## Structs ##

### SbDrmKeyId ###

#### Members ####

*   `uint8_t identifier`

    The ID of the license (or key) required to decrypt this sample. For
    PlayReady, this is the license GUID in packed little-endian binary form.
*   `int identifier_size`

### SbDrmSampleInfo ###

All the optional information needed per sample for encrypted samples.

#### Members ####

*   `uint8_t initialization_vector`

    The Initialization Vector needed to decrypt this sample.
*   `int initialization_vector_size`
*   `uint8_t identifier`

    The ID of the license (or key) required to decrypt this sample. For
    PlayReady, this is the license GUID in packed little-endian binary form.
*   `int identifier_size`
*   `int32_t subsample_count`

    The number of subsamples in this sample, must be at least 1.
*   `constSbDrmSubSampleMapping* subsample_mapping`

    The clear/encrypted mapping of each subsample in this sample. This must be
    an array of `subsample_count` mappings.

### SbDrmSubSampleMapping ###

A mapping of clear and encrypted bytes for a single subsample. All subsamples
within a sample must be encrypted with the same encryption parameters. The clear
bytes always appear first in the sample.

#### Members ####

*   `int32_t clear_byte_count`

    How many bytes of the corresponding subsample are not encrypted
*   `int32_t encrypted_byte_count`

    How many bytes of the corresponding subsample are encrypted.

## Functions ##

### SbDrmCloseSession ###

Clear any internal states/resources related to the specified `session_id`.

#### Declaration ####

```
void SbDrmCloseSession(SbDrmSystem drm_system, const void *session_id, int session_id_size)
```

### SbDrmCreateSystem ###

Creates a new DRM system that can be used when constructing an SbPlayer or an
SbDecoder.

This function returns kSbDrmSystemInvalid if `key_system` is unsupported.

Also see the documentation of SbDrmGenerateSessionUpdateRequest() and
SbDrmUpdateSession() for more details.

`key_system`: The DRM key system to be created. The value should be in the form
of "com.example.somesystem" as suggested by [https://w3c.github.io/encrypted-media/#key-system](https://w3c.github.io/encrypted-media/#key-system)) . All
letters in the value should be lowercase and will be matched exactly with known
DRM key systems of the platform. `context`: A value passed when any of this
function's callback parameters are called. `update_request_callback`: A function
that is called every time after SbDrmGenerateSessionUpdateRequest() is called.
`session_updated_callback`: A function that is called every time after
SbDrmUpdateSession() is called. `key_statuses_changed_callback`: A function that
can be called to indicate that key statuses have changed.
`server_certificate_updated_callback`: A function that is called to report
whether the server certificate has been successfully updated. It is called once
and only once. It is possible that the callback is called before the function
returns. `session_closed_callback`: A function that can be called to indicate
that a session has closed.

#### Declaration ####

```
SbDrmSystem SbDrmCreateSystem(const char *key_system, void *context, SbDrmSessionUpdateRequestFunc update_request_callback, SbDrmSessionUpdatedFunc session_updated_callback, SbDrmSessionKeyStatusesChangedFunc key_statuses_changed_callback, SbDrmSessionClosedFunc session_closed_callback)
```

### SbDrmDestroySystem ###

Destroys `drm_system`, which implicitly removes all keys installed in it and
invalidates all outstanding session update requests. A DRM system cannot be
destroyed unless any associated SbPlayer or SbDecoder has first been destroyed.

All callbacks are guaranteed to be finished when this function returns. As a
result, if this function is called from a callback that is passed to
SbDrmCreateSystem(), a deadlock will occur.

`drm_system`: The DRM system to be destroyed.

#### Declaration ####

```
void SbDrmDestroySystem(SbDrmSystem drm_system)
```

### SbDrmGenerateSessionUpdateRequest ###

Asynchronously generates a session update request payload for
`initialization_data`, of `initialization_data_size`, in case sensitive `type`,
extracted from the media stream, in `drm_system`'s key system.

This function calls `drm_system`'s `update_request_callback` function, which is
defined when the DRM system is created by SbDrmCreateSystem. When calling that
function, this function either sends `context` (also from `SbDrmCreateSystem`)
and a populated request, or it sends NULL `session_id` if an error occurred.

`drm_system`'s `context` may be used to route callbacks back to an object
instance.

Callbacks may be called either from the current thread before this function
returns or from another thread.

`drm_system`: The DRM system that defines the key system used for the session
update request payload as well as the callback function that is called as a
result of the function being called.

`ticket`: The opaque ID that allows to distinguish callbacks from multiple
concurrent calls to SbDrmGenerateSessionUpdateRequest(), which will be passed to
`update_request_callback` as-is. It is the responsibility of the caller to
establish ticket uniqueness, issuing multiple requests with the same ticket may
result in undefined behavior. The value `kSbDrmTicketInvalid` must not be used.

`type`: The case-sensitive type of the session update request payload.
`initialization_data`: The data for which the session update request payload is
created. `initialization_data_size`: The size of the session update request
payload.

#### Declaration ####

```
void SbDrmGenerateSessionUpdateRequest(SbDrmSystem drm_system, int ticket, const char *type, const void *initialization_data, int initialization_data_size)
```

### SbDrmGetKeyCount ###

Returns the number of keys installed in `drm_system`.

`drm_system`: The system for which the number of installed keys is retrieved.

#### Declaration ####

```
int SbDrmGetKeyCount(SbDrmSystem drm_system)
```

### SbDrmGetKeyStatus ###

Gets `out_key`, `out_key_size`, and `out_status` for the key with `index` in
`drm_system`. Returns whether a key is installed at `index`. If not, the output
parameters, which all must not be NULL, will not be modified.

#### Declaration ####

```
bool SbDrmGetKeyStatus(SbDrmSystem drm_system, const void *session_id, int session_id_size, int index, void **out_key, int *out_key_size, SbDrmKeyStatus *out_status)
```

### SbDrmRemoveAllKeys ###

Removes all installed keys for `drm_system`. Any outstanding session update
requests are also invalidated.

`drm_system`: The DRM system for which keys should be removed.

#### Declaration ####

```
void SbDrmRemoveAllKeys(SbDrmSystem drm_system)
```

### SbDrmSystemIsValid ###

Indicates whether `drm_system` is a valid SbDrmSystem.

#### Declaration ####

```
static bool SbDrmSystemIsValid(SbDrmSystem drm)
```

### SbDrmTicketIsValid ###

Indicates whether `ticket` is a valid ticket.

#### Declaration ####

```
static bool SbDrmTicketIsValid(int ticket)
```

### SbDrmUpdateSession ###

Update session with `key`, in `drm_system`'s key system, from the license server
response. Calls `session_updated_callback` with `context` and whether the update
succeeded. `context` may be used to route callbacks back to an object instance.

`ticket` is the opaque ID that allows to distinguish callbacks from multiple
concurrent calls to SbDrmUpdateSession(), which will be passed to
`session_updated_callback` as-is. It is the responsibility of the caller to
establish ticket uniqueness, issuing multiple calls with the same ticket may
result in undefined behavior.

Once the session is successfully updated, an SbPlayer or SbDecoder associated
with that DRM key system will be able to decrypt encrypted samples.

`drm_system`'s `session_updated_callback` may called either from the current
thread before this function returns or from another thread.

#### Declaration ####

```
void SbDrmUpdateSession(SbDrmSystem drm_system, int ticket, const void *key, int key_size, const void *session_id, int session_id_size)
```