Class AesCtr

Converts a raw private key in bytes to its corresponding JSON Web Key (JWK) format.

Remarks

This method takes a symmetric key represented as a byte array (Uint8Array) and converts it into a JWK object for use with AES (Advanced Encryption Standard) in Counter (CTR) mode. The conversion process involves encoding the key into base64url format and setting the appropriate JWK parameters.

The resulting JWK object includes the following properties:

• kty: Key Type, set to 'oct' for Octet Sequence (representing a symmetric key).
• k: The symmetric key, base64url-encoded.
• kid: Key ID, generated based on the JWK thumbprint.

Example

const privateKeyBytes = new Uint8Array([...]); // Replace with actual symmetric key bytes
const privateKey = await AesCtr.bytesToPrivateKey({ privateKeyBytes });
Copy

Decrypts the provided data using AES in Counter (CTR) mode.

Remarks

This method performs AES-CTR decryption on the given encrypted data using the specified key. Similar to the encryption process, it requires an initial counter block and the length of the counter block, along with the encrypted data and the decryption key. The method returns the decrypted data as a Uint8Array.

Example

const encryptedData = new Uint8Array([...]); // Encrypted data
const counter = new Uint8Array(16); // 16-byte (128-bit) counter block used during encryption
const key = { ... }; // A Jwk object representing the same AES key used for encryption
const decryptedData = await AesCtr.decrypt({
  data: encryptedData,
  counter,
  key,
  length: 64 // Length of the counter in bits
});
Copy

Encrypts the provided data using AES in Counter (CTR) mode.

Remarks

This method performs AES-CTR encryption on the given data using the specified key. It requires the initial counter block and the length of the counter block, alongside the data and key. The method is designed to work asynchronously and returns the encrypted data as a Uint8Array.

Example

const data = new TextEncoder().encode('Messsage');
const counter = new Uint8Array(16); // 16-byte (128-bit) counter block
const key = { ... }; // A Jwk object representing an AES key
const encryptedData = await AesCtr.encrypt({
  data,
  counter,
  key,
  length: 64 // Length of the counter in bits
});
Copy

Generates a symmetric key for AES in Counter (CTR) mode in JSON Web Key (JWK) format.

Remarks

This method creates a new symmetric key of a specified length suitable for use with AES-CTR encryption. It uses cryptographically secure random number generation to ensure the uniqueness and security of the key. The generated key adheres to the JWK format, making it compatible with common cryptographic standards and easy to use in various cryptographic processes.

The generated key includes the following components:

• kty: Key Type, set to 'oct' for Octet Sequence.
• k: The symmetric key component, base64url-encoded.
• kid: Key ID, generated based on the JWK thumbprint.

Example

const length = 256; // Length of the key in bits (e.g., 128, 192, 256)
const privateKey = await AesCtr.generateKey({ length });
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Converts a private key from JSON Web Key (JWK) format to a raw byte array (Uint8Array).

Remarks

This method takes a symmetric key in JWK format and extracts its raw byte representation. It decodes the 'k' parameter of the JWK value, which represents the symmetric key in base64url encoding, into a byte array.

Example

const privateKey = { ... }; // A symmetric key in JWK format
const privateKeyBytes = await AesCtr.privateKeyToBytes({ privateKey });
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