AVContentKeySession Best Practices

Transcription

1 Session #WWDC18 AVContentKeySession Best Practices 507 Anil Katti, AVFoundation Engineer 2018 Apple Inc. All rights reserved. Redistribution or public display not permitted without written permission from Apple.

2 Agenda

3 Agenda FairPlay Streaming overview

4 Agenda FairPlay Streaming overview AVContentKeySession API

5 Agenda FairPlay Streaming overview AVContentKeySession API Common pitfalls around key delivery

6 Agenda FairPlay Streaming overview AVContentKeySession API Common pitfalls around key delivery Frequently asked questions

7 FairPlay Streaming Overview

8 FairPlay Streaming Overview Introduced in 2015 Protects HLS streams

9 FairPlay Streaming Overview Introduced in 2015 Protects HLS streams Specifies steps to securely deliver content decryption keys

10 FairPlay Streaming Overview

11 FairPlay Streaming Overview Application

12 FairPlay Streaming Overview Application FPS Key Server Module Apple Platform

13 FairPlay Streaming Overview Application AVFoundation Delegate AVAssetResourceLoaderDelegate FPS Key Server Module AVFoundation AVAssetResourceLoader Apple Platform

14 FairPlay Streaming Overview Application AVFoundation Delegate AVAssetResourceLoaderDelegate FPS Load Key Key Server Module AVFoundation AVAssetResourceLoader Apple Platform

15 FairPlay Streaming Overview Application AVFoundation Delegate AVAssetResourceLoaderDelegate SPC = Secure Playback Context (Encrypted Key Request) Load Key Get SPC FPS Key Server Module AVFoundation AVAssetResourceLoader Apple Platform

16 FairPlay Streaming Overview Application AVFoundation Delegate AVAssetResourceLoaderDelegate SPC = Secure Playback Context (Encrypted Key Request) Load Key Get SPC SPC FPS Key Server Module AVFoundation AVAssetResourceLoader Apple Platform

17 FairPlay Streaming Overview Application SPC AVFoundation Delegate AVAssetResourceLoaderDelegate SPC = Secure Playback Context (Encrypted Key Request) Load Key Get SPC SPC FPS Key Server Module AVFoundation AVAssetResourceLoader Apple Platform

18 FairPlay Streaming Overview Application SPC CKC AVFoundation Delegate AVAssetResourceLoaderDelegate SPC = Secure Playback Context (Encrypted Key Request) CKC = Content Key Context (Encrypted Key Response) Load Key Get SPC SPC FPS Key Server Module AVFoundation AVAssetResourceLoader Apple Platform

19 FairPlay Streaming Overview Application SPC CKC AVFoundation Delegate AVAssetResourceLoaderDelegate SPC = Secure Playback Context (Encrypted Key Request) CKC = Content Key Context (Encrypted Key Response) Load Key Get SPC SPC CKC FPS Key Server Module AVFoundation AVAssetResourceLoader Apple Platform

20 FairPlay Streaming Overview Application SPC CKC AVAssetResourceLoaderDelegate SPC = Secure Playback Context (Encrypted Key Request) CKC = Content Key Context (Encrypted Key Response) Load Key Get SPC SPC CKC FPS Key Server Module AVAssetResourceLoader Apple Platform

21 AVContentKeySession

22 AVContentKeySession Introduced in 2017

23 AVContentKeySession Introduced in 2017 Designed around content decryption keys

24 AVContentKeySession Introduced in 2017 Designed around content decryption keys Simplified key loading process

25 AVContentKeySession Introduced in 2017 Designed around content decryption keys Simplified key loading process Home for new content protection features

26 AVContentKeySession Introduced in 2017 Designed around content decryption keys Simplified key loading process Home for new content protection features Great adoption - helps optimize key delivery

27 AVAssetResourceLoader Application AVAssetResourceLoaderDelegate AVAssetResourceLoader Apple Platform

28 AVAssetResourceLoader Application AVAssetResourceLoaderDelegate Load Key Key AVAssetResourceLoader Apple Platform

29 AVAssetResourceLoader Application AVAssetResourceLoaderDelegate Load Key Key AVAssetResourceLoader Apple Platform

30 AVContentKeySession Application AVAssetResourceLoaderDelegate AVAssetResourceLoader Apple Platform

31 AVContentKeySession Application AVContentKeySessionDelegate AVContentKeySession Apple Platform

32 AVContentKeySession Application AVContentKeySessionDelegate Initiate Key Loading Load Key Key AVContentKeySession Apple Platform

33 How Do I Reduce Playback Startup Delay?

34 How Do I Reduce Playback Startup Delay? Preload keys that you predict might be used

35 How Do I Reduce Playback Startup Delay? Preload keys that you predict might be used Batch up key requests - reduce round-trips to key server

36 How Do I Reduce Playback Startup Delay? Preload keys that you predict might be used Batch up key requests - reduce round-trips to key server //Initiate Key Loading Process contentkeysession.processcontentkeyrequest(withidentifier: "skd://mykey", initializationdata: nil, options: nil) //Delegate Callback func contentkeysession(_ session: AVContentKeySession, didprovide keyrequest: AVContentKeyRequest)

37 How Do I Reduce Playback Startup Delay? Preload keys that you predict might be used Batch up key requests - reduce round-trips to key server //Initiate Key Loading Process contentkeysession.processcontentkeyrequest(withidentifier: "skd://mykey", initializationdata: nil, options: nil) //Delegate Callback func contentkeysession(_ session: AVContentKeySession, didprovide keyrequest: AVContentKeyRequest)

38 Could A Key Be Requested Again?

39 Could A Key Be Requested Again? Yes

40 Could A Key Be Requested Again? Yes New keys might be required for decryption (AirPlay, Lightning Digital AV Adapter)

41 Could A Key Be Requested Again? Yes New keys might be required for decryption (AirPlay, Lightning Digital AV Adapter) Always be prepared to answer redundant key requests

42 How Do I Preload All Keys?

43 How Do I Preload All Keys? Need key identifier to load key

44 How Do I Preload All Keys? Need key identifier to load key Obtain all key identifiers out-of-band

45 How Do I Preload All Keys? Need key identifier to load key Obtain all key identifiers out-of-band Advertise session keys ( EXT-X-SESSION-KEY ) in master m3u8 Initiate preloading urlasset.resourceloader.preloadseligiblecontentkeys = true

46 How Do I Preload All Keys? Need key identifier to load key Obtain all key identifiers out-of-band Advertise session keys ( EXT-X-SESSION-KEY ) in master m3u8 Initiate preloading urlasset.resourceloader.preloadseligiblecontentkeys = true Measuring and Optimizing HLS Performance WWDC 2018

47 How Can My Live Streams Avoid The Thundering Herd?

48 How Can My Live Streams Avoid The Thundering Herd? Disperse key request events

49 How Can My Live Streams Avoid The Thundering Herd? Disperse key request events Clients rotate keys at the same time -> impulse load on key server

50 How Can My Live Streams Avoid The Thundering Herd? Disperse key request events Clients rotate keys at the same time -> impulse load on key server Load keys before EXT-X-KEY tag appears

51 How Can My Live Streams Avoid The Thundering Herd? Disperse key request events Clients rotate keys at the same time -> impulse load on key server Load keys before EXT-X-KEY tag appears Scale live offering by load balancing key loading requests

52 How Can My Live Streams Avoid The Thundering Herd? Disperse key request events Clients rotate keys at the same time -> impulse load on key server Load keys before EXT-X-KEY tag appears Scale live offering by load balancing key loading requests Advances in HTTP Live Streaming WWDC 2017

53 What Is Offline Rentals?

54 What Is Offline Rentals? Define two expiration durations on offline FairPlay Streaming keys

55 What Is Offline Rentals? Define two expiration durations on offline FairPlay Streaming keys Storage duration Persistent Key Expires in 30 days

56 What Is Offline Rentals? Define two expiration durations on offline FairPlay Streaming keys Storage duration Playback duration Persistent Key Persistent Key Expires in 24 hours

57 What Is Offline Rentals? Define two expiration durations on offline FairPlay Streaming keys Storage duration Playback duration Expiration durations are enforced even when the device is offline Persistent Key Persistent Key Expires in 24 hours

58 How Do I Do Offline Rentals?

59 How Do I Do Offline Rentals? Use Offline Key TLLV

60 How Do I Do Offline Rentals? Use Offline Key TLLV Signaled in CKC used while requesting persistent key

61 How Do I Do Offline Rentals?

62 How Do I Do Offline Rentals? //Requesting persistent key from AVPersistableContentKeyRequest let persistentkey = try persistablekeyrequest.persistablecontentkey(fromkeyvendorresponse: ckcdata, options: nil)

63 How Do I Do Offline Rentals? //Requesting persistent key from AVPersistableContentKeyRequest let persistentkey = try persistablekeyrequest.persistablecontentkey(fromkeyvendorresponse: ckcdata, options: nil) Persistent Key

64 How Do I Do Offline Rentals? //Requesting persistent key from AVPersistableContentKeyRequest let persistentkey = try persistablekeyrequest.persistablecontentkey(fromkeyvendorresponse: ckcdata, options: nil) Persistent Key

65 How Do I Do Offline Rentals? //Requesting persistent key from AVPersistableContentKeyRequest let persistentkey = try persistablekeyrequest.persistablecontentkey(fromkeyvendorresponse: ckcdata, options: nil) Expires in 30 days Persistent Key

66 How Do I Do Offline Rentals? //Requesting persistent key from AVPersistableContentKeyRequest let persistentkey = try persistablekeyrequest.persistablecontentkey(fromkeyvendorresponse: ckcdata, options: nil) Persistent Key Persistent Key Expires in 30 days

67 How Do I Do Offline Rentals? Persistent Key Persistent Key Expires in 30 days

68 How Do I Do Offline Rentals? //Delegate Callback func contentkeysession(_ session: AVContentKeySession, didupdatepersistablecontentkey persistablecontentkey: Data, forcontentkeyidentifier keyidentifier: Any) Expires in 30 days Persistent Key Updated Persistent Key

69 How Do I Do Offline Rentals? //Delegate Callback func contentkeysession(_ session: AVContentKeySession, didupdatepersistablecontentkey persistablecontentkey: Data, forcontentkeyidentifier keyidentifier: Any) Expires in 30 days Updated Persistent Key Updated Persistent Key

70 How Do I Do Offline Rentals? //Delegate Callback func contentkeysession(_ session: AVContentKeySession, didupdatepersistablecontentkey persistablecontentkey: Data, forcontentkeyidentifier keyidentifier: Any) Expires in 24 hours Updated Persistent Key Updated Persistent Key

71 How Do I Handle Errors While Loading Keys?

72 How Do I Handle Errors While Loading Keys? When something fails

73 How Do I Handle Errors While Loading Keys? When something fails Report error to AVFoundation //Setting error on an AVContentKeyRequest contentkeyrequest.processcontentkeyresponseerror(error) //Setting error on an AVAssetResourceLoadingRequest resourceloadingrequest.finishloading(with: error)

74 How Do I Handle Errors While Loading Keys? When something fails Report error to AVFoundation //Setting error on an AVContentKeyRequest contentkeyrequest.processcontentkeyresponseerror(error) //Setting error on an AVAssetResourceLoadingRequest resourceloadingrequest.finishloading(with: error) Monitor error logs and address root-cause

75 How Do I Handle Errors While Loading Keys? When something fails Report error to AVFoundation //Setting error on an AVContentKeyRequest contentkeyrequest.processcontentkeyresponseerror(error) //Setting error on an AVAssetResourceLoadingRequest resourceloadingrequest.finishloading(with: error) Monitor error logs and address root-cause Error Handling Best Practices for HTTP Live Streaming WWDC 2017

76 Common Pitfalls While Delivering Keys

77 Common Pitfalls While Delivering Keys Taking too long to provide key response Player times out waiting for key response

78 Common Pitfalls While Delivering Keys Taking too long to provide key response Player times out waiting for key response Deliver keys as soon as possible

79 Common Pitfalls While Delivering Keys Taking too long to provide key response Player times out waiting for key response Deliver keys as soon as possible Survey playeritem.accesslogs()

80 Common Pitfalls While Delivering Keys

81 Common Pitfalls While Delivering Keys Using same keys across variants with different HDCP requirements HDCP requirement is signaled inside key response

82 Common Pitfalls While Delivering Keys Using same keys across variants with different HDCP requirements HDCP requirement is signaled inside key response Use multiple key identifiers

83 Common Pitfalls While Delivering Keys

84 Common Pitfalls While Delivering Keys Using persistent keys to answer all key loading requests Persistent keys cannot be shared across devices (AirPlay)

85 Common Pitfalls While Delivering Keys Using persistent keys to answer all key loading requests Persistent keys cannot be shared across devices (AirPlay) Make sure key loading request accepts persistent keys

86 Common Pitfalls While Delivering Keys Using persistent keys to answer all key loading requests Persistent keys cannot be shared across devices (AirPlay) Make sure key loading request accepts persistent keys Minor API changes in ios 11.2+

87 Is Persistent Key Accepted As Response?

88 Is Persistent Key Accepted As Response? Using AVContentKeySession do { try contentkeyrequest.respondbyrequestingpersistablecontentkeyrequestandreturnerror() } catch { //Fallback to provide online FairPlay Streaming key from key server }

89 Is Persistent Key Accepted As Response?

90 Is Persistent Key Accepted As Response? Using AVAssetResourceLoader if let contenttypes = resourceloadingrequest.contentinformationrequest?.allowedcontenttypes,!contenttypes.contains(avstreamingkeydeliverypersistentcontentkeytype) { //Fallback to provide online FairPlay Streaming key from key server }

91 Summary

92 Summary AVContentKeySession API

93 Summary AVContentKeySession API How to improve playback startup?

94 Summary AVContentKeySession API How to improve playback startup? How to scale live streaming?

95 Summary AVContentKeySession API How to improve playback startup? How to scale live streaming? How to do offline rentals?

96 Summary AVContentKeySession API How to improve playback startup? How to scale live streaming? How to do offline rentals? How to handle failures while loading keys?

97 Summary AVContentKeySession API How to improve playback startup? How to scale live streaming? How to do offline rentals? How to handle failures while loading keys? How to avoid common pitfalls while delivering keys?

98 More Information

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