1# Encryption and Decryption with an AES Symmetric Key (ECB Mode) (ArkTS)
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3
4For details about the algorithm specifications, see [AES](crypto-sym-encrypt-decrypt-spec.md#aes).
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6
7**Encryption**
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101. Use [cryptoFramework.createSymKeyGenerator](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreatesymkeygenerator) and [SymKeyGenerator.generateSymKey](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#generatesymkey-1) to generate a 128-bit AES symmetric key (**SymKey**).
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12   In addition to the example in this topic, [AES](crypto-sym-key-generation-conversion-spec.md#aes) and [Randomly Generating a Symmetric Key](crypto-generate-sym-key-randomly.md) may help you better understand how to generate an AES symmetric key. Note that the input parameters in the reference documents may be different from those in the example below.
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142. Use [cryptoFramework.createCipher](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreatecipher) with the string parameter **'AES128|ECB|PKCS7'** to create a **Cipher** instance. The key type is **AES128**, block cipher mode is **ECB**, and the padding mode is **PKCS7**.
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163. Use [Cipher.init](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#init-1) to initialize the **Cipher** instance. In the **Cipher.init** API, set **opMode** to **CryptoMode.ENCRYPT_MODE** (encryption), **key** to **SymKey** (the key for encryption), and **params** to **IvParamsSpec** corresponding to the ECB mode.
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184. If a small amount of data is to be encrypted, use [Cipher.doFinal](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#dofinal-1) after **Cipher.init** to generate the ciphertext.
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20
21**Decryption**
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241. Use [Cipher.init](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#init-1) to initialize the **Cipher** instance. In the **Cipher.init** API, set **opMode** to **CryptoMode.DECRYPT_MODE** (decryption), **key** to **SymKey** (the key for decryption), and **params** to **IvParamsSpec** corresponding to the ECB mode.
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262. If a small amount of data is to be decrypted, you can use [Cipher.doFinal](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#dofinal-1) after **Cipher.init** to generate the plaintext.
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29- Example (using asynchronous APIs):
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31  ```ts
32  import { cryptoFramework } from '@kit.CryptoArchitectureKit';
33  import { buffer } from '@kit.ArkTS';
34
35  // Encrypt the message.
36  async function encryptMessagePromise(symKey: cryptoFramework.SymKey, plainText: cryptoFramework.DataBlob) {
37    let cipher = cryptoFramework.createCipher('AES128|ECB|PKCS7');
38    await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, symKey, null);
39    let cipherData = await cipher.doFinal(plainText);
40    return cipherData;
41  }
42  // Decrypt the message.
43  async function decryptMessagePromise(symKey: cryptoFramework.SymKey, cipherText: cryptoFramework.DataBlob) {
44    let decoder = cryptoFramework.createCipher('AES128|ECB|PKCS7');
45    await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, symKey, null);
46    let decryptData = await decoder.doFinal(cipherText);
47    return decryptData;
48  }
49
50  async function genSymKeyByData(symKeyData: Uint8Array) {
51    let symKeyBlob: cryptoFramework.DataBlob = { data: symKeyData };
52    let aesGenerator = cryptoFramework.createSymKeyGenerator('AES128');
53    let symKey = await aesGenerator.convertKey(symKeyBlob);
54    console.info('convertKey success');
55    return symKey;
56  }
57
58  async function aesECB() {
59    try {
60      let keyData = new Uint8Array([83, 217, 231, 76, 28, 113, 23, 219, 250, 71, 209, 210, 205, 97, 32, 159]);
61      let symKey = await genSymKeyByData(keyData);
62      let message = "This is a test";
63      let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(message, 'utf-8').buffer) };
64      let encryptText = await encryptMessagePromise(symKey, plainText);
65      let decryptText = await decryptMessagePromise(symKey, encryptText);
66      if (plainText.data.toString() === decryptText.data.toString()) {
67        console.info('decrypt ok');
68        console.info('decrypt plainText: ' + buffer.from(decryptText.data).toString('utf-8'));
69      } else {
70        console.error('decrypt failed');
71      }
72    } catch (error) {
73      console.error(`AES ECB "${error}", error code: ${error.code}`);
74    }
75  }
76  ```
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78- Example (using synchronous APIs):
79
80  ```ts
81  import { cryptoFramework } from '@kit.CryptoArchitectureKit';
82  import { buffer } from '@kit.ArkTS';
83
84  // Encrypt the message.
85  function encryptMessage(symKey: cryptoFramework.SymKey, plainText: cryptoFramework.DataBlob) {
86    let cipher = cryptoFramework.createCipher('AES128|ECB|PKCS7');
87    cipher.initSync(cryptoFramework.CryptoMode.ENCRYPT_MODE, symKey, null);
88    let cipherData = cipher.doFinalSync(plainText);
89    return cipherData;
90  }
91  // Decrypt the message.
92  function decryptMessage(symKey: cryptoFramework.SymKey, cipherText: cryptoFramework.DataBlob) {
93    let decoder = cryptoFramework.createCipher('AES128|ECB|PKCS7');
94    decoder.initSync(cryptoFramework.CryptoMode.DECRYPT_MODE, symKey, null);
95    let decryptData = decoder.doFinalSync(cipherText);
96    return decryptData;
97  }
98
99  function genSymKeyByData(symKeyData: Uint8Array) {
100    let symKeyBlob: cryptoFramework.DataBlob = { data: symKeyData };
101    let aesGenerator = cryptoFramework.createSymKeyGenerator('AES128');
102    let symKey = aesGenerator.convertKeySync(symKeyBlob);
103    console.info('convertKeySync success');
104    return symKey;
105  }
106
107  function main() {
108    try {
109      let keyData = new Uint8Array([83, 217, 231, 76, 28, 113, 23, 219, 250, 71, 209, 210, 205, 97, 32, 159]);
110      let symKey = genSymKeyByData(keyData);
111      let message = "This is a test";
112      let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(message, 'utf-8').buffer) };
113      let encryptText = encryptMessage(symKey, plainText);
114      let decryptText = decryptMessage(symKey, encryptText);
115      if (plainText.data.toString() === decryptText.data.toString()) {
116        console.info('decrypt ok');
117        console.info('decrypt plainText: ' + buffer.from(decryptText.data).toString('utf-8'));
118      } else {
119        console.error('decrypt failed');
120      }
121    } catch (error) {
122      console.error(`AES ECB "${error}", error code: ${error.code}`);
123    }
124  }
125  ```
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