1# SE Access Development 2 3## Introduction 4An electronic device may have one or more secure elements (SEs), such as the embedded SE (eSE) and SIM card. Access control for SEs is implemented in accordance with the Global Platform Access Control (GPAC) specification. 5 6## When to Use 7An application may need to write data to an SE to emulate an NFC card on the device. The NFC card data may be stored on an eSE or a SIM card. Generally, SEs are preset with rules for access control. An application must have related permissions and can access an SE only after a successful permission verification. 8 9## Available APIs 10For details about the APIs and sample code, see [SE Management](../../reference/apis-connectivity-kit/js-apis-secureElement.md). 11 12The following table describes the APIs for SE access. 13 14| API | Description | 15| ---------------------------------- | ------------------------------------------------------------------------------ | 16| createService(): Promise\<SEService> | Creates an **SEService** instance for connecting to all available SEs in the system. | 17| getReaders(): Reader[] | Obtains available SE readers, which include all the SEs on the device. | 18| openSession(): Session | Opens a session to connect to an SE in this reader. This API returns a session instance. | 19| openLogicalChannel(aid: number[]): Promise\<Channel> | Opens a logical channel. This API returns a logical channel instance. | 20| transmit(command: number[]): Promise\<number[]> | Transmits application protocol data units (APDUs) to this SE. | 21| close(): void | Closes this channel. | 22 23 24## How to Develop 25 26### Accessing an SE 271. Import related modules. 282. Check whether the device supports SEs. 293. Access an SE and read or write data. 304. Release channel resources. 31 32```ts 33import { omapi } from '@kit.ConnectivityKit'; 34import { BusinessError } from '@kit.BasicServicesKit'; 35import { hilog } from '@kit.PerformanceAnalysisKit'; 36import { AbilityConstant, UIAbility, Want } from '@kit.AbilityKit'; 37 38let seService : omapi.SEService; 39let seReaders : omapi.Reader[]; 40let seSession : omapi.Session; 41let seChannel : omapi.Channel; 42let testSelectedAid : number[] = [0xA0, 0x00, 0x00, 0x00, 0x03, 0x10, 0x10]; 43let p2 : number = 0x00; 44 45export default class EntryAbility extends UIAbility { 46 onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) { 47 hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate'); 48 49 // Check whether the device supports SEs. 50 if (!canIUse("SystemCapability.Communication.SecureElement")) { 51 hilog.error(0x0000, 'testTag', 'secure element unavailable.'); 52 return; 53 } 54 hilog.info(0x0000, 'testTag', 'secure element available.'); 55 this.omaTest(); 56 } 57 58 private async omaTest () { 59 // Create an SEService instance for SE access. 60 await omapi.createService().then((data) => { 61 if (data == undefined || !data.isConnected()) { 62 hilog.error(0x0000, 'testTag', 'secure element service disconnected.'); 63 return; 64 } 65 seService = data; 66 hilog.info(0x0000, 'testTag', 'secure element service connected.'); 67 }).catch((error: BusinessError) => { 68 hilog.error(0x0000, 'testTag', 'createService error %{public}s', JSON.stringify(error)); 69 return; 70 }); 71 72 // Obtain all supported readers on the device, that is, the list of all SEs. 73 try { 74 seReaders = seService.getReaders(); 75 } catch (error) { 76 hilog.error(0x0000, 'testTag', 'getReaders error %{public}s', JSON.stringify(error)); 77 } 78 if (seReaders == undefined || seReaders.length == 0) { 79 hilog.error(0x0000, 'testTag', 'no valid reader found.'); 80 seService.shutdown(); 81 return; 82 } 83 84 // Select an SE (eSE or SIM card) for access based on the service requirements. 85 let reader: (omapi.Reader | undefined); 86 for (let i = 0; i < seReaders.length; ++i) { 87 let r = seReaders[i]; 88 // Distinguish the SE by name, for example, eSE or SIM. 89 if (r.getName().includes("SIM")) { 90 reader = r; 91 break; 92 } 93 } 94 if (reader == undefined) { 95 hilog.error(0x0000, 'testTag', 'no valid sim reader.'); 96 seService.shutdown(); 97 return; 98 } 99 hilog.info(0x0000, 'testTag', 'reader is %{public}s', reader?.getName()); 100 101 // Open a session on a specified SE instance. 102 try { 103 seSession = reader?.openSession() as omapi.Session; 104 } catch (error) { 105 hilog.error(0x0000, 'testTag', 'openSession error %{public}s', JSON.stringify(error)); 106 } 107 if (seSession == undefined) { 108 hilog.error(0x0000, 'testTag', 'seSession invalid.'); 109 seService.shutdown(); 110 return; 111 } 112 113 // Create a logical channel or basic channel via the session instance. Generally, the logical channel is used for access, as the basic channel may be restricted. 114 try { 115 // Change the value of testSelectedAid to the AID of the application that opens the logical channel. 116 seChannel = await seSession.openLogicalChannel(testSelectedAid, p2); 117 } catch (exception) { 118 hilog.error(0x0000, 'testTag', 'openLogicalChannel exception %{public}s', JSON.stringify(exception)); 119 } 120 121 if (seChannel == undefined) { 122 hilog.error(0x0000, 'testTag', 'seChannel invalid.'); 123 seService.shutdown(); 124 return; 125 } 126 127 // Send APDUs to the SE over the logical channel. Set testApduData correctly based on actual service requirements, and ensue that the APDU format complies with the APDU specification. 128 let testApduData = [0x01, 0x02, 0x03, 0x04]; 129 try { 130 let response: number[] = await seChannel.transmit(testApduData); 131 hilog.info(0x0000, 'testTag', 'seChannel.transmit() response = %{public}s.', JSON.stringify(response)); 132 } catch (exception) { 133 hilog.error(0x0000, 'testTag', 'seChannel.transmit() exception = %{public}s.', JSON.stringify(exception)); 134 } 135 136 // Close the channel to release resources when the SE access is complete. 137 try { 138 seChannel.close(); 139 } catch (exception) { 140 hilog.error(0x0000, 'testTag', 'seChannel.close() exception = %{public}s.', JSON.stringify(exception)); 141 } 142 143 // Close the service, and disable the binding relationship between the application and the SE service. 144 seService.shutdown(); 145 } 146} 147 148``` 149