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. A SIM card that functions as an SE must have the NFC feature. 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 JS APIs and sample code, see [SE Management](../../reference/apis-connectivity-kit/js-apis-secureElement.md). 11The following table describes the APIs for accessing SEs. 12 13| API | Description | 14| ---------------------------------- | ------------------------------------------------------------------------------ | 15| createService(): Promise\<SEService> | Creates an **SEService** instance for connecting to all available SEs in the system. | 16| getReaders(): Reader[] | Obtains available SE readers, which include all the SEs on the device. | 17| openSession(): Session | Opens a session to connect to an SE in this reader. This API returns a session instance. | 18| openLogicalChannel(aid: number[]): Promise\<Channel> | Opens a logical channel. This API returns a logical channel instance. | 19| transmit(command: number[]): Promise\<number[]> | Transmits APDU data to this SE. | 20| close(): void | Closes this channel. | 21 22 23## How to Develop 24 25### Accessing an SE 261. Import modules. 272. Check whether the device supports SEs. 283. Access an SE and read or write data. 29 30```ts 31import { omapi } from '@kit.ConnectivityKit'; 32import { BusinessError } from '@kit.BasicServicesKit'; 33import { hilog } from '@kit.PerformanceAnalysisKit'; 34import { AbilityConstant, UIAbility, Want } from '@kit.AbilityKit'; 35 36let seService : omapi.SEService; 37let seReaders : omapi.Reader[]; 38let seSession : omapi.Session; 39let seChannel : omapi.Channel; 40let aidArray : number[] = [0xA0, 0x00, 0x00, 0x00, 0x03, 0x10, 0x10]; 41let p2 : number = 0x00; 42 43export default class EntryAbility extends UIAbility { 44 onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) { 45 hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate'); 46 47 // Check whether the device supports SEs. 48 if (!canIUse("SystemCapability.Communication.SecureElement")) { 49 hilog.error(0x0000, 'testTag', 'secure element unavailable.'); 50 return; 51 } 52 hilog.info(0x0000, 'testTag', 'secure element available.'); 53 this.omaTest(); 54 } 55 56 private async omaTest () { 57 // Obtain the service. 58 await omapi.createService().then((data) => { 59 if (data == undefined || !data.isConnected()) { 60 hilog.error(0x0000, 'testTag', 'secure element service disconnected.'); 61 return; 62 } 63 seService = data; 64 hilog.info(0x0000, 'testTag', 'secure element service connected.'); 65 }).catch((error: BusinessError) => { 66 hilog.error(0x0000, 'testTag', 'createService error %{public}s', JSON.stringify(error)); 67 return; 68 }); 69 70 // Obtain readers. 71 try { 72 seReaders = seService.getReaders(); 73 } catch (error) { 74 hilog.error(0x0000, 'testTag', 'getReaders error %{public}s', JSON.stringify(error)); 75 } 76 if (seReaders == undefined || seReaders.length == 0) { 77 hilog.error(0x0000, 'testTag', 'no valid reader found.'); 78 seService.shutdown(); 79 return; 80 } 81 let reader: (omapi.Reader | undefined); 82 for (let i = 0; i < seReaders.length; ++i) { 83 let r = seReaders[i]; 84 if (r.getName().includes("SIM")) { 85 reader = r; 86 break; 87 } 88 } 89 if (reader == undefined) { 90 hilog.error(0x0000, 'testTag', 'no valid sim reader.'); 91 return; 92 } 93 hilog.info(0x0000, 'testTag', 'reader is %{public}s', reader?.getName()); 94 95 // Obtain the session. 96 try { 97 seSession = reader?.openSession() as omapi.Session; 98 } catch (error) { 99 hilog.error(0x0000, 'testTag', 'openSession error %{public}s', JSON.stringify(error)); 100 } 101 if (seSession == undefined) { 102 hilog.error(0x0000, 'testTag', 'seSession invalid.'); 103 seService.shutdown(); 104 return; 105 } 106 107 // Obtain the channel. 108 try { 109 // change the aid value for open logical channel 110 // Change the value to the AID of the application for which the logical channel is opened. 111 seChannel = await seSession.openLogicalChannel(aidArray, p2); 112 } catch (exception) { 113 hilog.error(0x0000, 'testTag', 'openLogicalChannel exception %{public}s', JSON.stringify(exception)); 114 } 115 116 if (seChannel == undefined) { 117 hilog.error(0x0000, 'testTag', 'seChannel invalid.'); 118 return; 119 } 120 121 // Send data. 122 let cmdData = [0x01, 0x02, 0x03, 0x04]; // Set command data correctly. 123 try { 124 let response: number[] = await seChannel.transmit(cmdData) 125 hilog.info(0x0000, 'testTag', 'seChannel.transmit() response = %{public}s.', JSON.stringify(response)); 126 } catch (exception) { 127 hilog.error(0x0000, 'testTag', 'seChannel.transmit() exception = %{public}s.', JSON.stringify(exception)); 128 } 129 130 // Close the channel. After performing the operation, make sure that the channel is truly closed. 131 try { 132 seChannel.close(); 133 } catch (exception) { 134 hilog.error(0x0000, 'testTag', 'seChannel.close() exception = %{public}s.', JSON.stringify(exception)); 135 } 136 137 } 138} 139 140``` 141