@web5/agent
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text/typescript
import type { Jwk } from '@web5/crypto';
import type { KeyValueStore } from '@web5/common';
import { DidDhtCreateOptions } from '@web5/dids';
import { HDKey } from 'ed25519-keygen/hdkey';
import { BearerDid, DidDht } from '@web5/dids';
import { Convert, MemoryStore } from '@web5/common';
import { wordlist } from '@scure/bip39/wordlists/english';
import { generateMnemonic, mnemonicToSeed, validateMnemonic } from '@scure/bip39';
import type { JweHeaderParams } from './prototyping/crypto/jose/jwe.js';
import type { IdentityVaultBackup, IdentityVaultBackupData, IdentityVaultStatus, IdentityVaultParams, IdentityVault } from './types/identity-vault.js';
import { AgentCryptoApi } from './crypto-api.js';
import { LocalKeyManager } from './local-key-manager.js';
import { isPortableDid } from './prototyping/dids/utils.js';
import { DeterministicKeyGenerator } from './utils-internal.js';
import { CompactJwe } from './prototyping/crypto/jose/jwe-compact.js';
/**
* Extended initialization parameters for HdIdentityVault, including an optional recovery phrase
* that can be used to derive keys to encrypt the vault and generate a DID.
*/
export type HdIdentityVaultInitializeParams = {
/**
* The password used to secure the vault.
*
* The password selected should be strong and securely managed to prevent unauthorized access.
*/
password: string;
/**
* An optional recovery phrase used to derive the cryptographic keys for the vault.
*
* Providing a recovery phrase can be used to recover the vault's content or establish a
* deterministic key generation scheme. If not provided, a new recovery phrase will be generated
* during the initialization process.
*/
recoveryPhrase?: string;
/**
* Optional dwnEndpoints to register didService endpoints during HdIdentityVault initialization
*
* The dwnEndpoints are used to register a DWN endpoint during DidDht.create(). This allows the
* agent to properly recover connectedDids from DWN. Also, this pattern can be used on the server
* side in place of the agentDid-->connectedDids pattern.
*/
dwnEndpoints?: string[];
};
/**
* Type guard function to check if a given object is an empty string or a string containing only
* whitespace.
*
* This is an internal utility function used to validate password inputs, ensuring they are not
* empty or filled with only whitespace characters, which are considered invalid for password
* purposes.
*
* @param obj - The object to be checked, typically expected to be a password string.
* @returns A boolean value indicating whether the object is an empty string or a string with only
* whitespace.
*/
function isEmptyString(obj: unknown): obj is string {
return typeof obj !== 'string' || obj.trim().length === 0;
}
/**
* Type guard function to check if a given object conforms to the {@link IdentityVaultBackup}
* interface.
*
* This function is an internal utility meant to ensure the integrity and structure of the data
* assumed to be an {@link IdentityVaultBackup}. It verifies the presence and types of the
* `dateCreated`, `size`, and `data` properties, aligning with the expected structure of a backup
* object in the context of an {@link IdentityVault}.
*
* @param obj - The object to be verified against the {@link IdentityVaultBackup} interface.
* @returns A boolean value indicating whether the object is a valid {@link IdentityVaultBackup}.
*/
function isIdentityVaultBackup(obj: unknown): obj is IdentityVaultBackup {
return typeof obj === 'object' && obj !== null
&& 'dateCreated' in obj && typeof obj.dateCreated === 'string'
&& 'size' in obj && typeof obj.size === 'number'
&& 'data' in obj && typeof obj.data === 'string';
}
/**
* Internal-only type guard function that checks if a given object conforms to the
* {@link IdentityVaultStatus} interface.
*
* This function is utilized within the {@link HdIdentityVault} implementation to ensure the
* integrity of the object representing the vault's status, verifying the presence and types of
* required properties. It aasserts the presence and correct types of `initialized`, `lastBackup`,
* and `lastRestore` properties, ensuring they align with the expected structure of an identity
* vault's status.
*
* @param obj - The object to be checked against the {{@link IdentityVaultStatus} interface.
* @returns A boolean indicating whether the object is an instance of {@link IdentityVaultStatus}.
*/
function isIdentityVaultStatus(obj: unknown): obj is IdentityVaultStatus {
return typeof obj === 'object' && obj !== null
&& 'initialized' in obj && typeof obj.initialized === 'boolean'
&& 'lastBackup' in obj
&& 'lastRestore' in obj;
}
/**
* The `HdIdentityVault` class provides secure storage and management of identity data.
*
* The `HdIdentityVault` class implements the `IdentityVault` interface, providing secure storage
* and management of identity data with an added layer of security using Hierarchical Deterministic
* (HD) key derivation based on the SLIP-0010 standard for Ed25519 keys. It enhances identity
* protection by generating and securing the identity using a derived HD key, allowing for the
* deterministic regeneration of keys from a recovery phrase.
*
* The vault is capable of:
* - Secure initialization with a password and an optional recovery phrase, employing HD key
* derivation.
* - Encrypting the identity data using a derived content encryption key (CEK) which is securely
* encrypted and stored, accessible only by the correct password.
* - Securely backing up and restoring the vault’s contents, including the HD-derived keys and
* associated DID.
* - Locking and unlocking the vault, which encrypts and decrypts the CEK for secure access to the
* vault's contents.
* - Managing the DID associated with the identity, providing a secure identity layer for
* applications.
*
* Usage involves initializing the vault with a secure password (and optionally a recovery phrase),
* which then allows for the secure storage, backup, and retrieval of the identity data.
*
* Note: Ensure the password is strong and securely managed, as it is crucial for the security of the
* vault's encrypted contents.
*
* @example
* ```typescript
* const vault = new HdIdentityVault();
* await vault.initialize({ password: 'secure-unique-phrase', recoveryPhrase: 'twelve words ...' });
* const backup = await vault.backup();
* await vault.restore({ backup, password: 'secure-unique-phrase' });
* ```
*/
export class HdIdentityVault implements IdentityVault<{ InitializeResult: string }> {
/** Provides cryptographic functions needed for secure storage and management of the vault. */
public crypto = new AgentCryptoApi();
/** Determines the computational intensity of the key derivation process. */
private _keyDerivationWorkFactor: number;
/** The underlying key-value store for the vault's encrypted content. */
private _store: KeyValueStore<string, string>;
/** The cryptographic key used to encrypt and decrypt the vault's content securely. */
private _contentEncryptionKey: Jwk | undefined;
/**
* Constructs an instance of `HdIdentityVault`, initializing the key derivation factor and data
* store. It sets the default key derivation work factor and initializes the internal data store,
* either with the provided store or a default in-memory store. It also establishes the initial
* status of the vault as uninitialized and locked.
*
* @param params - Optional parameters when constructing a vault instance.
* @param params.keyDerivationWorkFactor - Optionally set the computational effort for key derivation.
* @param params.store - Optionally specify a custom key-value store for vault data.
*/
constructor({ keyDerivationWorkFactor, store }: IdentityVaultParams = {}) {
this._keyDerivationWorkFactor = keyDerivationWorkFactor ?? 210_000;
this._store = store ?? new MemoryStore<string, string>();
}
/**
* Creates a backup of the vault's current state, including the encrypted DID and content
* encryption key, and returns it as an `IdentityVaultBackup` object. The backup includes a
* Base64Url-encoded string representing the vault's encrypted data, encapsulating the
* {@link PortableDid}, the content encryption key, and the vault's status.
*
* This method ensures that the vault is initialized and unlocked before proceeding with the
* backup operation.
*
* @throws Error if the vault is not initialized or is locked, preventing the backup.
* @returns A promise that resolves to the `IdentityVaultBackup` object containing the vault's
* encrypted backup data.
*/
public async backup(): Promise<IdentityVaultBackup> {
// Verify the identity vault has already been initialized and unlocked.
if (this.isLocked() || await this.isInitialized() === false) {
throw new Error(
'HdIdentityVault: Unable to proceed with the backup operation because the identity vault ' +
'has not been initialized and unlocked. Please ensure the vault is properly initialized ' +
'with a secure password before attempting to backup its contents.'
);
}
// Encode the encrypted CEK and DID as a single Base64Url string.
const backupData: IdentityVaultBackupData = {
did : await this.getStoredDid(),
contentEncryptionKey : await this.getStoredContentEncryptionKey(),
status : await this.getStatus()
};
const backupDataString = Convert.object(backupData).toBase64Url();
// Create a backup object containing the encrypted vault contents.
const backup: IdentityVaultBackup = {
data : backupDataString,
dateCreated : new Date().toISOString(),
size : backupDataString.length
};
// Update the last backup timestamp in the data store.
await this.setStatus({ lastBackup: backup.dateCreated });
return backup;
}
/**
* Changes the password used to secure the vault.
*
* This method decrypts the existing content encryption key (CEK) with the old password, then
* re-encrypts it with the new password, updating the vault's stored encrypted CEK. It ensures
* that the vault is initialized and unlocks the vault if the password is successfully changed.
*
* @param params - Parameters required for changing the vault password.
* @param params.oldPassword - The current password used to unlock the vault.
* @param params.newPassword - The new password to replace the existing one.
* @throws Error if the vault is not initialized or the old password is incorrect.
* @returns A promise that resolves when the password change is complete.
*/
public async changePassword({ oldPassword, newPassword }: {
oldPassword: string;
newPassword: string;
}): Promise<void> {
// Verify the identity vault has already been initialized.
if (await this.isInitialized() === false) {
throw new Error(
'HdIdentityVault: Unable to proceed with the change password operation because the ' +
'identity vault has not been initialized. Please ensure the vault is properly ' +
'initialized with a secure password before trying again.'
);
}
// Lock the vault.
await this.lock();
// Retrieve the content encryption key (CEK) record as a compact JWE from the data store.
const cekJwe = await this.getStoredContentEncryptionKey();
// Decrypt the compact JWE using the given `oldPassword` to verify it is correct.
let protectedHeader: JweHeaderParams;
let contentEncryptionKey: Jwk;
try {
let contentEncryptionKeyBytes: Uint8Array;
({ plaintext: contentEncryptionKeyBytes, protectedHeader } = await CompactJwe.decrypt({
jwe : cekJwe,
key : Convert.string(oldPassword).toUint8Array(),
crypto : this.crypto,
keyManager : new LocalKeyManager()
}));
contentEncryptionKey = Convert.uint8Array(contentEncryptionKeyBytes).toObject() as Jwk;
} catch (error: any) {
throw new Error(`HdIdentityVault: Unable to change the vault password due to an incorrectly entered old password.`);
}
// Re-encrypt the vault content encryption key (CEK) using the new password.
const newCekJwe = await CompactJwe.encrypt({
key : Convert.string(newPassword).toUint8Array(),
protectedHeader, // Re-use the protected header from the original JWE.
plaintext : Convert.object(contentEncryptionKey).toUint8Array(),
crypto : this.crypto,
keyManager : new LocalKeyManager()
});
// Update the vault with the new CEK JWE.
await this._store.set('contentEncryptionKey', newCekJwe);
// Update the vault CEK in memory, effectively unlocking the vault.
this._contentEncryptionKey = contentEncryptionKey;
}
/**
* Retrieves the DID (Decentralized Identifier) associated with the vault.
*
* This method ensures the vault is initialized and unlocked before decrypting and returning the
* DID. The DID is stored encrypted and is decrypted using the vault's content encryption key.
*
* @throws Error if the vault is not initialized, is locked, or the DID cannot be decrypted.
* @returns A promise that resolves with a {@link BearerDid}.
*/
public async getDid(): Promise<BearerDid> {
// Verify the identity vault is unlocked.
if (this.isLocked()) {
throw new Error(`HdIdentityVault: Vault has not been initialized and unlocked.`);
}
// Retrieve the encrypted DID record as compact JWE from the vault store.
const didJwe = await this.getStoredDid();
// Decrypt the compact JWE to obtain the PortableDid as a byte array.
const { plaintext: portableDidBytes } = await CompactJwe.decrypt({
jwe : didJwe,
key : this._contentEncryptionKey!,
crypto : this.crypto,
keyManager : new LocalKeyManager()
});
// Convert the DID from a byte array to PortableDid format.
const portableDid = Convert.uint8Array(portableDidBytes).toObject();
if (!isPortableDid(portableDid)) {
throw new Error('HdIdentityVault: Unable to decode malformed DID in identity vault');
}
// Return the DID in Bearer DID format.
return await BearerDid.import({ portableDid });
}
/**
* Fetches the current status of the `HdIdentityVault`, providing details on whether it's
* initialized and the timestamps of the last backup and restore operations.
*
* @returns A promise that resolves with the current status of the `HdIdentityVault`, detailing
* its initialization, lock state, and the timestamps of the last backup and restore.
*/
public async getStatus(): Promise<IdentityVaultStatus> {
const storedStatus = await this._store.get('vaultStatus');
// On the first run, the store will not contain an IdentityVaultStatus object yet, so return an
// uninitialized status.
if (!storedStatus) {
return {
initialized : false,
lastBackup : null,
lastRestore : null
};
}
const vaultStatus = Convert.string(storedStatus).toObject();
if (!isIdentityVaultStatus(vaultStatus)) {
throw new Error('HdIdentityVault: Invalid IdentityVaultStatus object in store');
}
return vaultStatus;
}
/**
* Initializes the `HdIdentityVault` with a password and an optional recovery phrase.
*
* If a recovery phrase is not provided, a new one is generated. This process sets up the vault,
* deriving the necessary cryptographic keys and preparing the vault for use. It ensures the vault
* is ready to securely store and manage identity data.
*
* @example
* ```ts
* const identityVault = new HdIdentityVault();
* const recoveryPhrase = await identityVault.initialize({
* password: 'your-secure-phrase'
* });
* console.log('Vault initialized. Recovery phrase:', recoveryPhrase);
* ```
*
* @param params - The initialization parameters.
* @param params.password - The password used to secure the vault.
* @param params.recoveryPhrase - An optional 12-word recovery phrase for key derivation. If
* omitted, a new recovery is generated.
* @returns A promise that resolves with the recovery phrase used during the initialization, which
* should be securely stored by the user.
*/
public async initialize({ password, recoveryPhrase, dwnEndpoints }:
HdIdentityVaultInitializeParams
): Promise<string> {
/**
* STEP 0: Validate the input parameters and verify the identity vault is not already
* initialized.
*/
// Verify that the identity vault was not previously initialized.
if (await this.isInitialized()) {
throw new Error(`HdIdentityVault: Vault has already been initialized.`);
}
// Verify that the password is not empty.
if (isEmptyString(password)) {
throw new Error(
`HdIdentityVault: The password is required and cannot be blank. Please provide a ' +
'valid, non-empty password.`
);
}
// If provided, verify that the recovery phrase is not empty.
if (recoveryPhrase && isEmptyString(recoveryPhrase)) {
throw new Error(
`HdIdentityVault: The password is required and cannot be blank. Please provide a ' +
'valid, non-empty password.`
);
}
/**
* STEP 1: Derive a Hierarchical Deterministic (HD) key pair from the given (or generated)
* recoveryPhrase.
*/
// Generate a 12-word (128-bit) mnemonic, if one was not provided.
recoveryPhrase ??= generateMnemonic(wordlist, 128);
// Validate the mnemonic for being 12-24 words contained in `wordlist`.
if (!validateMnemonic(recoveryPhrase, wordlist)) {
throw new Error(
'HdIdentityVault: The provided recovery phrase is invalid. Please ensure that the ' +
'recovery phrase is a correctly formatted series of 12 words.'
);
}
// Derive a root seed from the mnemonic.
const rootSeed = await mnemonicToSeed(recoveryPhrase);
// Derive a root key for the DID from the root seed.
const rootHdKey = HDKey.fromMasterSeed(rootSeed);
/**
* STEP 2: Derive the vault HD key pair from the root key.
*/
// The vault HD key is derived using account 0 and index 0 so that it can be
// deterministically re-derived. The vault key pair serves as input keying material for:
// - deriving the vault content encryption key (CEK)
// - deriving the salt that serves as input to derive the key that encrypts the vault CEK
const vaultHdKey = rootHdKey.derive(`m/44'/0'/0'/0'/0'`);
/**
* STEP 3: Derive the vault Content Encryption Key (CEK) from the vault private
* key and a non-secret static info value.
*/
// A non-secret static info value is combined with the vault private key as input to HKDF
// (Hash-based Key Derivation Function) to derive a 32-byte content encryption key (CEK).
const contentEncryptionKey = await this.crypto.deriveKey({
algorithm : 'HKDF-512', // key derivation function
baseKeyBytes : vaultHdKey.privateKey, // input keying material
salt : '', // empty salt because private key is sufficiently random
info : 'vault_cek', // non-secret application specific information
derivedKeyAlgorithm : 'A256GCM' // derived key algorithm
});
/**
* STEP 4: Using the given `password` and a `salt` derived from the vault public key, encrypt
* the vault CEK and store it in the data store as a compact JWE.
*/
// A non-secret static info value is combined with the vault public key as input to HKDF
// (Hash-based Key Derivation Function) to derive a new 32-byte salt.
const saltInput = await this.crypto.deriveKeyBytes({
algorithm : 'HKDF-512', // key derivation function
baseKeyBytes : vaultHdKey.publicKey, // input keying material
salt : '', // empty salt because public key is sufficiently random
info : 'vault_unlock_salt', // non-secret application specific information
length : 256, // derived key length, in bits
});
// Construct the JWE header.
const cekJweProtectedHeader: JweHeaderParams = {
alg : 'PBES2-HS512+A256KW',
enc : 'A256GCM',
cty : 'text/plain',
p2c : this._keyDerivationWorkFactor,
p2s : Convert.uint8Array(saltInput).toBase64Url()
};
// Encrypt the vault content encryption key (CEK) to compact JWE format.
const cekJwe = await CompactJwe.encrypt({
key : Convert.string(password).toUint8Array(),
protectedHeader : cekJweProtectedHeader,
plaintext : Convert.object(contentEncryptionKey).toUint8Array(),
crypto : this.crypto,
keyManager : new LocalKeyManager()
});
// Store the compact JWE in the data store.
await this._store.set('contentEncryptionKey', cekJwe);
/**
* STEP 5: Create a DID using identity, signing, and encryption keys derived from the root key.
*/
// Derive the identity key pair using index 0 and convert to JWK format.
// Note: The account is set to Unix epoch time so that in the future, the keys for a DID DHT
// document can be deterministically derived based on the versionId returned in a DID
// resolution result.
const identityHdKey = rootHdKey.derive(`m/44'/0'/1708523827'/0'/0'`);
const identityPrivateKey = await this.crypto.bytesToPrivateKey({
algorithm : 'Ed25519',
privateKeyBytes : identityHdKey.privateKey
});
// Derive the signing key using index 1 and convert to JWK format.
let signingHdKey = rootHdKey.derive(`m/44'/0'/1708523827'/0'/1'`);
const signingPrivateKey = await this.crypto.bytesToPrivateKey({
algorithm : 'Ed25519',
privateKeyBytes : signingHdKey.privateKey
});
// TODO: Enable this once DID DHT supports X25519 keys.
// Derive the encryption key using index 1 and convert to JWK format.
// const encryptionHdKey = rootHdKey.derive(`m/44'/0'/1708523827'/0'/1'`);
// const encryptionKeyEd25519 = await this.crypto.bytesToPrivateKey({
// algorithm : 'Ed25519',
// privateKeyBytes : encryptionHdKey.privateKey
// });
// const encryptionPrivateKey = await Ed25519.convertPrivateKeyToX25519({ privateKey: encryptionKeyEd25519 });
// Add the identity and signing keys to the deterministic key generator so that when the DID is
// created it will use the derived keys.
const deterministicKeyGenerator = new DeterministicKeyGenerator();
await deterministicKeyGenerator.addPredefinedKeys({
privateKeys: [identityPrivateKey, signingPrivateKey]
});
// Create the DID using the derived identity, signing, and encryption keys.
const options = {
verificationMethods: [
{
algorithm : 'Ed25519',
id : 'sig',
purposes : ['assertionMethod', 'authentication']
},
]
} as DidDhtCreateOptions<DeterministicKeyGenerator>;
if(dwnEndpoints && !!dwnEndpoints.length) {
options.services = [
{
id : 'dwn',
type : 'DecentralizedWebNode',
serviceEndpoint : dwnEndpoints,
enc : '#enc',
sig : '#sig',
}
];
}
const did = await DidDht.create({ keyManager: deterministicKeyGenerator, options });
/**
* STEP 6: Convert the DID to portable format and store it in the data store as a
* compact JWE.
*/
// Convert the DID to a portable format.
const portableDid = await did.export();
// Construct the JWE header.
const didJweProtectedHeader: JweHeaderParams = {
alg : 'dir',
enc : 'A256GCM',
cty : 'json'
};
// Encrypt the DID to compact JWE format.
const didJwe = await CompactJwe.encrypt({
key : contentEncryptionKey,
plaintext : Convert.object(portableDid).toUint8Array(),
protectedHeader : didJweProtectedHeader,
crypto : this.crypto,
keyManager : new LocalKeyManager()
});
// Store the compact JWE in the data store.
await this._store.set('did', didJwe);
/**
* STEP 7: Set the vault CEK (effectively unlocking the vault), set the status to initialized,
* and return the mnemonic used to generate the vault key.
*/
this._contentEncryptionKey = contentEncryptionKey;
await this.setStatus({ initialized: true });
// Return the recovery phrase in case it was generated so that it can be displayed to the user
// for safekeeping.
return recoveryPhrase;
}
/**
* Determines whether the vault has been initialized.
*
* This method checks the vault's current status to determine if it has been
* initialized. Initialization is a prerequisite for most operations on the vault,
* ensuring that it is ready for use.
*
* @example
* ```ts
* const isInitialized = await identityVault.isInitialized();
* console.log('Is the vault initialized?', isInitialized);
* ```
*
* @returns A promise that resolves to `true` if the vault has been initialized, otherwise `false`.
*/
public async isInitialized(): Promise<boolean> {
return this.getStatus().then(({ initialized }) => initialized);
}
/**
* Checks if the vault is currently locked.
*
* This method assesses the vault's current state to determine if it is locked.
* A locked vault restricts access to its contents, requiring the correct password
* to unlock and access the stored identity data. The vault must be unlocked to
* perform operations that access or modify its contents.
*
* @example
* ```ts
* const isLocked = await identityVault.isLocked();
* console.log('Is the vault locked?', isLocked);
* ```
*
* @returns `true` if the vault is locked, otherwise `false`.
*/
public isLocked(): boolean {
return !this._contentEncryptionKey;
}
/**
* Locks the `HdIdentityVault`, securing its contents by clearing the in-memory encryption key.
*
* This method ensures that the vault's sensitive data cannot be accessed without unlocking the
* vault again with the correct password. It's an essential security feature for safeguarding
* the vault's contents against unauthorized access.
*
* @example
* ```ts
* const identityVault = new HdIdentityVault();
* await identityVault.lock();
* console.log('Vault is now locked.');
* ```
* @throws An error if the identity vault has not been initialized.
* @returns A promise that resolves when the vault is successfully locked.
*/
public async lock(): Promise<void> {
// Verify the identity vault has already been initialized.
if (await this.isInitialized() === false) {
throw new Error(`HdIdentityVault: Lock operation failed. Vault has not been initialized.`);
}
// Clear the vault content encryption key (CEK), effectively locking the vault.
if (this._contentEncryptionKey) this._contentEncryptionKey.k = '';
this._contentEncryptionKey = undefined;
}
/**
* Restores the vault's data from a backup object, decrypting and reinitializing the vault's
* content with the provided backup data.
*
* This operation is crucial for data recovery scenarios, allowing users to regain access to their
* encrypted data using a previously saved backup and their password.
*
* @example
* ```ts
* const identityVault = new HdIdentityVault();
* await identityVault.initialize({ password: 'your-secure-phrase' });
* // Create a backup of the vault's contents.
* const backup = await identityVault.backup();
* // Restore the vault with the same password.
* await identityVault.restore({ backup: backup, password: 'your-secure-phrase' });
* console.log('Vault restored successfully.');
* ```
*
* @param params - The parameters required for the restore operation.
* @param params.backup - The backup object containing the encrypted vault data.
* @param params.password - The password used to encrypt the backup, necessary for decryption.
* @returns A promise that resolves when the vault has been successfully restored.
* @throws An error if the backup object is invalid or if the password is incorrect.
*/
public async restore({ backup, password }: {
backup: IdentityVaultBackup;
password: string;
}): Promise<void> {
// Validate the backup object.
if (!isIdentityVaultBackup(backup)) {
throw new Error(`HdIdentityVault: Restore operation failed due to invalid backup object.`);
}
// Temporarily save the status and contents of the data store while attempting to restore the
// backup so that they are not lost in case the restore operation fails.
let previousStatus: IdentityVaultStatus;
let previousContentEncryptionKey: string;
let previousDid: string;
try {
previousDid = await this.getStoredDid();
previousContentEncryptionKey = await this.getStoredContentEncryptionKey();
previousStatus = await this.getStatus();
} catch {
throw new Error(
'HdIdentityVault: The restore operation cannot proceed because the existing vault ' +
'contents are missing or inaccessible. If the problem persists consider re-initializing ' +
'the vault and retrying the restore.'
);
}
try {
// Convert the backup data to a JSON object.
const backupData = Convert.base64Url(backup.data).toObject() as IdentityVaultBackupData;
// Restore the backup to the data store.
await this._store.set('did', backupData.did);
await this._store.set('contentEncryptionKey', backupData.contentEncryptionKey);
await this.setStatus(backupData.status);
// Attempt to unlock the vault with the given `password`.
await this.unlock({ password });
} catch (error: any) {
// If the restore operation fails, revert the data store to the status and contents that were
// saved before the restore operation was attempted.
await this.setStatus(previousStatus);
await this._store.set('contentEncryptionKey', previousContentEncryptionKey);
await this._store.set('did', previousDid);
throw new Error(
'HdIdentityVault: Restore operation failed due to invalid backup data or an incorrect ' +
'password. Please verify the password is correct for the provided backup and try again.'
);
}
// Update the last restore timestamp in the data store.
await this.setStatus({ lastRestore: new Date().toISOString() });
}
/**
* Unlocks the vault by decrypting the stored content encryption key (CEK) using the provided
* password.
*
* This method is essential for accessing the vault's encrypted contents, enabling the decryption
* of stored data and the execution of further operations requiring the vault to be unlocked.
*
* @example
* ```ts
* const identityVault = new HdIdentityVault();
* await identityVault.initialize({ password: 'your-initial-phrase' });
* // Unlock the vault with the correct password before accessing its contents
* await identityVault.unlock({ password: 'your-initial-phrase' });
* console.log('Vault unlocked successfully.');
* ```
*
*
* @param params - The parameters required for the unlock operation.
* @param params.password - The password used to encrypt the vault's CEK, necessary for
* decryption.
* @returns A promise that resolves when the vault has been successfully unlocked.
* @throws An error if the vault has not been initialized or if the provided password is
* incorrect.
*/
public async unlock({ password }: { password: string }): Promise<void> {
// Lock the vault.
await this.lock();
// Retrieve the content encryption key (CEK) record as a compact JWE from the data store.
const cekJwe = await this.getStoredContentEncryptionKey();
// Decrypt the compact JWE.
try {
const { plaintext: contentEncryptionKeyBytes } = await CompactJwe.decrypt({
jwe : cekJwe,
key : Convert.string(password).toUint8Array(),
crypto : this.crypto,
keyManager : new LocalKeyManager()
});
const contentEncryptionKey = Convert.uint8Array(contentEncryptionKeyBytes).toObject() as Jwk;
// Save the content encryption key in memory, thereby unlocking the vault.
this._contentEncryptionKey = contentEncryptionKey;
} catch (error: any) {
throw new Error(`HdIdentityVault: Unable to unlock the vault due to an incorrect password.`);
}
}
/**
* Retrieves the Decentralized Identifier (DID) associated with the identity vault from the vault
* store.
*
* This DID is encrypted in compact JWE format and needs to be decrypted after the vault is
* unlocked. The method is intended to be used internally within the HdIdentityVault class to access
* the encrypted PortableDid.
*
* @returns A promise that resolves to the encrypted DID stored in the vault as a compact JWE.
* @throws Will throw an error if the DID cannot be retrieved from the vault.
*/
private async getStoredDid(): Promise<string> {
// Retrieve the DID record as a compact JWE from the data store.
const didJwe = await this._store.get('did');
if (!didJwe) {
throw new Error(
'HdIdentityVault: Unable to retrieve the DID record from the vault. Please check the ' +
'vault status and if the problem persists consider re-initializing the vault and ' +
'restoring the contents from a previous backup.'
);
}
return didJwe;
}
/**
* Retrieves the encrypted Content Encryption Key (CEK) from the vault's storage.
*
* This CEK is used for encrypting and decrypting the vault's contents. It is stored as a
* compact JWE and should be decrypted with the user's password to be used for further
* cryptographic operations.
*
* @returns A promise that resolves to the stored CEK as a string in compact JWE format.
* @throws Will throw an error if the CEK cannot be retrieved, indicating potential issues with
* the vault's integrity or state.
*/
private async getStoredContentEncryptionKey(): Promise<string> {
// Retrieve the content encryption key (CEK) record as a compact JWE from the data store.
const cekJwe = await this._store.get('contentEncryptionKey');
if (!cekJwe) {
throw new Error(
'HdIdentityVault: Unable to retrieve the Content Encryption Key record from the vault. ' +
'Please check the vault status and if the problem persists consider re-initializing the ' +
'vault and restoring the contents from a previous backup.'
);
}
return cekJwe;
}
/**
* Updates the status of the `HdIdentityVault`, reflecting changes in its initialization, lock
* state, and the timestamps of the last backup and restore operations.
*
* This method directly manipulates the internal state stored in the vault's key-value store.
*
* @param params - The status properties to be updated.
* @param params.initialized - Updates the initialization state of the vault.
* @param params.lastBackup - Updates the timestamp of the last successful backup.
* @param params.lastRestore - Updates the timestamp of the last successful restore.
* @returns A promise that resolves to a boolean indicating successful status update.
* @throws Will throw an error if the status cannot be updated in the key-value store.
*/
private async setStatus({ initialized, lastBackup, lastRestore }: Partial<IdentityVaultStatus>): Promise<boolean> {
// Get the current status values from the store, if any.
let vaultStatus = await this.getStatus();
// Update the status properties with new values specified, if any.
vaultStatus.initialized = initialized ?? vaultStatus.initialized;
vaultStatus.lastBackup = lastBackup ?? vaultStatus.lastBackup;
vaultStatus.lastRestore = lastRestore ?? vaultStatus.lastRestore;
// Write the changes to the store.
await this._store.set('vaultStatus', JSON.stringify(vaultStatus));
return true;
}
}