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Web Crypto API

Node.js provides an implementation of the Web Crypto API standard.

Use globalThis.crypto or require('node:crypto').webcrypto to access this module.

const { subtle } = globalThis.crypto;

(async function() {

  const key = await subtle.generateKey({
    name: 'HMAC',
    hash: 'SHA-256',
    length: 256,
  }, true, ['sign', 'verify']);

  const enc = new TextEncoder();
  const message = enc.encode('I love cupcakes');

  const digest = await subtle.sign({
    name: 'HMAC',
  }, key, message);

})();
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Modern Algorithms in the Web Cryptography API

Node.js provides an implementation of the following features from the Modern Algorithms in the Web Cryptography API WICG proposal:

Algorithms:

• 'AES-OCB'¹
• 'Argon2d'²
• 'Argon2i'²
• 'Argon2id'²
• 'ChaCha20-Poly1305'
• 'cSHAKE128'
• 'cSHAKE256'
• 'KMAC128'¹
• 'KMAC256'¹
• 'ML-DSA-44'³
• 'ML-DSA-65'³
• 'ML-DSA-87'³
• 'ML-KEM-512'³
• 'ML-KEM-768'³
• 'ML-KEM-1024'³
• 'SHA3-256'
• 'SHA3-384'
• 'SHA3-512'

Key Formats:

• 'raw-public'
• 'raw-secret'
• 'raw-seed'

Methods:

• subtle.decapsulateBits()
• subtle.decapsulateKey()
• subtle.encapsulateBits()
• subtle.encapsulateKey()
• subtle.getPublicKey()
• SubtleCrypto.supports()

Secure Curves in the Web Cryptography API

Node.js provides an implementation of the following features from the Secure Curves in the Web Cryptography API WICG proposal:

Algorithms:

• 'Ed448'
• 'X448'

Examples

Generating keys

The <SubtleCrypto> class can be used to generate symmetric (secret) keys or asymmetric key pairs (public key and private key).

AES keys

const { subtle } = globalThis.crypto;

async function generateAesKey(length = 256) {
  const key = await subtle.generateKey({
    name: 'AES-CBC',
    length,
  }, true, ['encrypt', 'decrypt']);

  return key;
}
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ECDSA key pairs

const { subtle } = globalThis.crypto;

async function generateEcKey(namedCurve = 'P-521') {
  const {
    publicKey,
    privateKey,
  } = await subtle.generateKey({
    name: 'ECDSA',
    namedCurve,
  }, true, ['sign', 'verify']);

  return { publicKey, privateKey };
}
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Ed25519/X25519 key pairs

const { subtle } = globalThis.crypto;

async function generateEd25519Key() {
  return subtle.generateKey({
    name: 'Ed25519',
  }, true, ['sign', 'verify']);
}

async function generateX25519Key() {
  return subtle.generateKey({
    name: 'X25519',
  }, true, ['deriveKey']);
}
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HMAC keys

const { subtle } = globalThis.crypto;

async function generateHmacKey(hash = 'SHA-256') {
  const key = await subtle.generateKey({
    name: 'HMAC',
    hash,
  }, true, ['sign', 'verify']);

  return key;
}
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RSA key pairs

const { subtle } = globalThis.crypto;
const publicExponent = new Uint8Array([1, 0, 1]);

async function generateRsaKey(modulusLength = 2048, hash = 'SHA-256') {
  const {
    publicKey,
    privateKey,
  } = await subtle.generateKey({
    name: 'RSASSA-PKCS1-v1_5',
    modulusLength,
    publicExponent,
    hash,
  }, true, ['sign', 'verify']);

  return { publicKey, privateKey };
}
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Encryption and decryption

const crypto = globalThis.crypto;

async function aesEncrypt(plaintext) {
  const ec = new TextEncoder();
  const key = await generateAesKey();
  const iv = crypto.getRandomValues(new Uint8Array(16));

  const ciphertext = await crypto.subtle.encrypt({
    name: 'AES-CBC',
    iv,
  }, key, ec.encode(plaintext));

  return {
    key,
    iv,
    ciphertext,
  };
}

async function aesDecrypt(ciphertext, key, iv) {
  const dec = new TextDecoder();
  const plaintext = await crypto.subtle.decrypt({
    name: 'AES-CBC',
    iv,
  }, key, ciphertext);

  return dec.decode(plaintext);
}
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Exporting and importing keys

const { subtle } = globalThis.crypto;

async function generateAndExportHmacKey(format = 'jwk', hash = 'SHA-512') {
  const key = await subtle.generateKey({
    name: 'HMAC',
    hash,
  }, true, ['sign', 'verify']);

  return subtle.exportKey(format, key);
}

async function importHmacKey(keyData, format = 'jwk', hash = 'SHA-512') {
  const key = await subtle.importKey(format, keyData, {
    name: 'HMAC',
    hash,
  }, true, ['sign', 'verify']);

  return key;
}
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Wrapping and unwrapping keys

const { subtle } = globalThis.crypto;

async function generateAndWrapHmacKey(format = 'jwk', hash = 'SHA-512') {
  const [
    key,
    wrappingKey,
  ] = await Promise.all([
    subtle.generateKey({
      name: 'HMAC', hash,
    }, true, ['sign', 'verify']),
    subtle.generateKey({
      name: 'AES-KW',
      length: 256,
    }, true, ['wrapKey', 'unwrapKey']),
  ]);

  const wrappedKey = await subtle.wrapKey(format, key, wrappingKey, 'AES-KW');

  return { wrappedKey, wrappingKey };
}

async function unwrapHmacKey(
  wrappedKey,
  wrappingKey,
  format = 'jwk',
  hash = 'SHA-512') {

  const key = await subtle.unwrapKey(
    format,
    wrappedKey,
    wrappingKey,
    'AES-KW',
    { name: 'HMAC', hash },
    true,
    ['sign', 'verify']);

  return key;
}
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Sign and verify

const { subtle } = globalThis.crypto;

async function sign(key, data) {
  const ec = new TextEncoder();
  const signature =
    await subtle.sign('RSASSA-PKCS1-v1_5', key, ec.encode(data));
  return signature;
}

async function verify(key, signature, data) {
  const ec = new TextEncoder();
  const verified =
    await subtle.verify(
      'RSASSA-PKCS1-v1_5',
      key,
      signature,
      ec.encode(data));
  return verified;
}
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Deriving bits and keys

const { subtle } = globalThis.crypto;

async function pbkdf2(pass, salt, iterations = 1000, length = 256) {
  const ec = new TextEncoder();
  const key = await subtle.importKey(
    'raw',
    ec.encode(pass),
    'PBKDF2',
    false,
    ['deriveBits']);
  const bits = await subtle.deriveBits({
    name: 'PBKDF2',
    hash: 'SHA-512',
    salt: ec.encode(salt),
    iterations,
  }, key, length);
  return bits;
}

async function pbkdf2Key(pass, salt, iterations = 1000, length = 256) {
  const ec = new TextEncoder();
  const keyMaterial = await subtle.importKey(
    'raw',
    ec.encode(pass),
    'PBKDF2',
    false,
    ['deriveKey']);
  const key = await subtle.deriveKey({
    name: 'PBKDF2',
    hash: 'SHA-512',
    salt: ec.encode(salt),
    iterations,
  }, keyMaterial, {
    name: 'AES-GCM',
    length,
  }, true, ['encrypt', 'decrypt']);
  return key;
}
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Digest

const { subtle } = globalThis.crypto;

async function digest(data, algorithm = 'SHA-512') {
  const ec = new TextEncoder();
  const digest = await subtle.digest(algorithm, ec.encode(data));
  return digest;
}
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Checking for runtime algorithm support

SubtleCrypto.supports() allows feature detection in Web Crypto API, which can be used to detect whether a given algorithm identifier (including its parameters) is supported for the given operation.

This example derives a key from a password using Argon2, if available, or PBKDF2, otherwise; and then encrypts and decrypts some text with it using AES-OCB, if available, and AES-GCM, otherwise.

const { SubtleCrypto, crypto } = globalThis;

const password = 'correct horse battery staple';
const derivationAlg =
  SubtleCrypto.supports?.('importKey', 'Argon2id') ?
    'Argon2id' :
    'PBKDF2';
const encryptionAlg =
  SubtleCrypto.supports?.('importKey', 'AES-OCB') ?
    'AES-OCB' :
    'AES-GCM';
const passwordKey = await crypto.subtle.importKey(
  derivationAlg === 'Argon2id' ? 'raw-secret' : 'raw',
  new TextEncoder().encode(password),
  derivationAlg,
  false,
  ['deriveKey'],
);
const nonce = crypto.getRandomValues(new Uint8Array(16));
const derivationParams =
  derivationAlg === 'Argon2id' ?
    {
      nonce,
      parallelism: 4,
      memory: 2 ** 21,
      passes: 1,
    } :
    {
      salt: nonce,
      iterations: 100_000,
      hash: 'SHA-256',
    };
const key = await crypto.subtle.deriveKey(
  {
    name: derivationAlg,
    ...derivationParams,
  },
  passwordKey,
  {
    name: encryptionAlg,
    length: 256,
  },
  false,
  ['encrypt', 'decrypt'],
);
const plaintext = 'Hello, world!';
const iv = crypto.getRandomValues(new Uint8Array(16));
const encrypted = await crypto.subtle.encrypt(
  { name: encryptionAlg, iv },
  key,
  new TextEncoder().encode(plaintext),
);
const decrypted = new TextDecoder().decode(await crypto.subtle.decrypt(
  { name: encryptionAlg, iv },
  key,
  encrypted,
));
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Algorithm matrix

The tables details the algorithms supported by the Node.js Web Crypto API implementation and the APIs supported for each:

Key Management APIs

Crypto Operation APIs

Column Legend:

• Encryption: subtle.encrypt() / subtle.decrypt()
• Signatures and MAC: subtle.sign() / subtle.verify()
• Key or Bits Derivation: subtle.deriveBits() / subtle.deriveKey()
• Key Wrapping: subtle.wrapKey() / subtle.unwrapKey()
• Key Encapsulation: subtle.encapsulateBits() / subtle.decapsulateBits() / subtle.encapsulateKey() / subtle.decapsulateKey()
• Digest: subtle.digest()

Class: Crypto

globalThis.crypto is an instance of the Crypto class. Crypto is a singleton that provides access to the remainder of the crypto API.

crypto.subtle

• Type: <SubtleCrypto>

Provides access to the SubtleCrypto API.

crypto.getRandomValues(typedArray)

• typedArray <Buffer> | <TypedArray>
• Returns: <Buffer> | <TypedArray>

Generates cryptographically strong random values. The given typedArray is filled with random values, and a reference to typedArray is returned.

The given typedArray must be an integer-based instance of <TypedArray>, i.e. Float32Array and Float64Array are not accepted.

An error will be thrown if the given typedArray is larger than 65,536 bytes.

crypto.randomUUID()

• Returns: <string>

Generates a random RFC 4122 version 4 UUID. The UUID is generated using a cryptographic pseudorandom number generator.

Class: CryptoKey

cryptoKey.algorithm

• Type: <KeyAlgorithm> | <RsaHashedKeyAlgorithm> | <EcKeyAlgorithm> | <AesKeyAlgorithm> | <HmacKeyAlgorithm>

An object detailing the algorithm for which the key can be used along with additional algorithm-specific parameters.

Read-only.

cryptoKey.extractable

• Type: <boolean>

When true, the <CryptoKey> can be extracted using either subtle.exportKey() or subtle.wrapKey().

Read-only.

cryptoKey.type

• Type: <string> One of 'secret', 'private', or 'public'.

A string identifying whether the key is a symmetric ('secret') or asymmetric ('private' or 'public') key.

cryptoKey.usages

• Type: <string[]>

An array of strings identifying the operations for which the key may be used.

The possible usages are:

• 'encrypt' - Enable using the key with subtle.encrypt()
• 'decrypt' - Enable using the key with subtle.decrypt()
• 'sign' - Enable using the key with subtle.sign()
• 'verify' - Enable using the key with subtle.verify()
• 'deriveKey' - Enable using the key with subtle.deriveKey()
• 'deriveBits' - Enable using the key with subtle.deriveBits()
• 'encapsulateBits' - Enable using the key with subtle.encapsulateBits()
• 'decapsulateBits' - Enable using the key with subtle.decapsulateBits()
• 'encapsulateKey' - Enable using the key with subtle.encapsulateKey()
• 'decapsulateKey' - Enable using the key with subtle.decapsulateKey()
• 'wrapKey' - Enable using the key with subtle.wrapKey()
• 'unwrapKey' - Enable using the key with subtle.unwrapKey()

Valid key usages depend on the key algorithm (identified by cryptokey.algorithm.name).

Column Legend:

• Encryption: subtle.encrypt() / subtle.decrypt()
• Signatures and MAC: subtle.sign() / subtle.verify()
• Key or Bits Derivation: subtle.deriveBits() / subtle.deriveKey()
• Key Wrapping: subtle.wrapKey() / subtle.unwrapKey()
• Key Encapsulation: subtle.encapsulateBits() / subtle.decapsulateBits() / subtle.encapsulateKey() / subtle.decapsulateKey()

Class: CryptoKeyPair

The CryptoKeyPair is a simple dictionary object with publicKey and privateKey properties, representing an asymmetric key pair.

cryptoKeyPair.privateKey

• Type: <CryptoKey> A <CryptoKey> whose type will be 'private'.

cryptoKeyPair.publicKey

• Type: <CryptoKey> A <CryptoKey> whose type will be 'public'.

Class: SubtleCrypto

Static method: SubtleCrypto.supports(operation, algorithm[, lengthOrAdditionalAlgorithm])

• operation <string> "encrypt", "decrypt", "sign", "verify", "digest", "generateKey", "deriveKey", "deriveBits", "importKey", "exportKey", "getPublicKey", "wrapKey", "unwrapKey", "encapsulateBits", "encapsulateKey", "decapsulateBits", or "decapsulateKey"
• algorithm <string> | <Algorithm>
• lengthOrAdditionalAlgorithm <null> | <number> | <string> | <Algorithm> | <undefined> Depending on the operation this is either ignored, the value of the length argument when operation is "deriveBits", the algorithm of key to be derived when operation is "deriveKey", the algorithm of key to be exported before wrapping when operation is "wrapKey", the algorithm of key to be imported after unwrapping when operation is "unwrapKey", or the algorithm of key to be imported after en/decapsulating a key when operation is "encapsulateKey" or "decapsulateKey". Default: null when operation is "deriveBits", undefined otherwise.
• Returns: <boolean> Indicating whether the implementation supports the given operation

Allows feature detection in Web Crypto API, which can be used to detect whether a given algorithm identifier (including its parameters) is supported for the given operation.

See Checking for runtime algorithm support for an example use of this method.

subtle.decapsulateBits(decapsulationAlgorithm, decapsulationKey, ciphertext)

• decapsulationAlgorithm <string> | <Algorithm>
• decapsulationKey <CryptoKey>
• ciphertext <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>
• Returns: <Promise> Fulfills with <ArrayBuffer> upon success.

A message recipient uses their asymmetric private key to decrypt an "encapsulated key" (ciphertext), thereby recovering a temporary symmetric key (represented as <ArrayBuffer>) which is then used to decrypt a message.

The algorithms currently supported include:

• 'ML-KEM-512'⁴
• 'ML-KEM-768'⁴
• 'ML-KEM-1024'⁴

subtle.decapsulateKey(decapsulationAlgorithm, decapsulationKey, ciphertext, sharedKeyAlgorithm, extractable, usages)

• decapsulationAlgorithm <string> | <Algorithm>
• decapsulationKey <CryptoKey>
• ciphertext <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>
• sharedKeyAlgorithm <string> | <Algorithm> | <HmacImportParams> | <AesDerivedKeyParams>
• extractable <boolean>
• usages <string[]> See Key usages.
• Returns: <Promise> Fulfills with <CryptoKey> upon success.

A message recipient uses their asymmetric private key to decrypt an "encapsulated key" (ciphertext), thereby recovering a temporary symmetric key (represented as <CryptoKey>) which is then used to decrypt a message.

The algorithms currently supported include:

• 'ML-KEM-512'⁴
• 'ML-KEM-768'⁴
• 'ML-KEM-1024'⁴

subtle.decrypt(algorithm, key, data)

• algorithm <RsaOaepParams> | <AesCtrParams> | <AesCbcParams>
• key <CryptoKey>
• data <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>
• Returns: <Promise> Fulfills with an <ArrayBuffer> upon success.

Using the method and parameters specified in algorithm and the keying material provided by key, this method attempts to decipher the provided data. If successful, the returned promise will be resolved with an <ArrayBuffer> containing the plaintext result.

The algorithms currently supported include:

• 'AES-CBC'
• 'AES-CTR'
• 'AES-GCM'
• 'AES-OCB'⁴
• 'ChaCha20-Poly1305'⁴
• 'RSA-OAEP'

subtle.deriveBits(algorithm, baseKey[, length])

• algorithm <EcdhKeyDeriveParams> | <HkdfParams> | <Pbkdf2Params>
• baseKey <CryptoKey>
• length <number> | <null> Default: null
• Returns: <Promise> Fulfills with an <ArrayBuffer> upon success.

Using the method and parameters specified in algorithm and the keying material provided by baseKey, this method attempts to generate length bits.

When length is not provided or null the maximum number of bits for a given algorithm is generated. This is allowed for the 'ECDH', 'X25519', and 'X448'⁵ algorithms, for other algorithms length is required to be a number.

If successful, the returned promise will be resolved with an <ArrayBuffer> containing the generated data.

The algorithms currently supported include:

• 'Argon2d'⁴
• 'Argon2i'⁴
• 'Argon2id'⁴
• 'ECDH'
• 'HKDF'
• 'PBKDF2'
• 'X25519'
• 'X448'⁵

subtle.deriveKey(algorithm, baseKey, derivedKeyAlgorithm, extractable, keyUsages)

• algorithm <EcdhKeyDeriveParams> | <HkdfParams> | <Pbkdf2Params>
• baseKey <CryptoKey>
• derivedKeyAlgorithm <string> | <Algorithm> | <HmacImportParams> | <AesDerivedKeyParams>
• extractable <boolean>
• keyUsages <string[]> See Key usages.
• Returns: <Promise> Fulfills with a <CryptoKey> upon success.

Using the method and parameters specified in algorithm, and the keying material provided by baseKey, this method attempts to generate a new <CryptoKey> based on the method and parameters in derivedKeyAlgorithm.

Calling this method is equivalent to calling subtle.deriveBits() to generate raw keying material, then passing the result into the subtle.importKey() method using the deriveKeyAlgorithm, extractable, and keyUsages parameters as input.

The algorithms currently supported include:

• 'Argon2d'⁴
• 'Argon2i'⁴
• 'Argon2id'⁴
• 'ECDH'
• 'HKDF'
• 'PBKDF2'
• 'X25519'
• 'X448'⁵

subtle.digest(algorithm, data)

• algorithm <string> | <Algorithm>
• data <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>
• Returns: <Promise> Fulfills with an <ArrayBuffer> upon success.

Using the method identified by algorithm, this method attempts to generate a digest of data. If successful, the returned promise is resolved with an <ArrayBuffer> containing the computed digest.

If algorithm is provided as a <string>, it must be one of:

• 'cSHAKE128'⁴
• 'cSHAKE256'⁴
• 'SHA-1'
• 'SHA-256'
• 'SHA-384'
• 'SHA-512'
• 'SHA3-256'⁴
• 'SHA3-384'⁴
• 'SHA3-512'⁴

If algorithm is provided as an <Object>, it must have a name property whose value is one of the above.

subtle.encapsulateBits(encapsulationAlgorithm, encapsulationKey)

• encapsulationAlgorithm <string> | <Algorithm>
• encapsulationKey <CryptoKey>
• Returns: <Promise> Fulfills with {EncapsulatedBits} upon success.

Uses a message recipient's asymmetric public key to encrypt a temporary symmetric key. This encrypted key is the "encapsulated key" represented as {EncapsulatedBits}.

The algorithms currently supported include:

• 'ML-KEM-512'⁴
• 'ML-KEM-768'⁴
• 'ML-KEM-1024'⁴

subtle.encapsulateKey(encapsulationAlgorithm, encapsulationKey, sharedKeyAlgorithm, extractable, usages)

• encapsulationAlgorithm <string> | <Algorithm>
• encapsulationKey <CryptoKey>
• sharedKeyAlgorithm <string> | <Algorithm> | <HmacImportParams> | <AesDerivedKeyParams>
• extractable <boolean>
• usages <string[]> See Key usages.
• Returns: <Promise> Fulfills with {EncapsulatedKey} upon success.

Uses a message recipient's asymmetric public key to encrypt a temporary symmetric key. This encrypted key is the "encapsulated key" represented as {EncapsulatedKey}.

The algorithms currently supported include:

• 'ML-KEM-512'⁴
• 'ML-KEM-768'⁴
• 'ML-KEM-1024'⁴

subtle.encrypt(algorithm, key, data)

• algorithm <RsaOaepParams> | <AesCtrParams> | <AesCbcParams>
• key <CryptoKey>
• data <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>
• Returns: <Promise> Fulfills with an <ArrayBuffer> upon success.

Using the method and parameters specified by algorithm and the keying material provided by key, this method attempts to encipher data. If successful, the returned promise is resolved with an <ArrayBuffer> containing the encrypted result.

The algorithms currently supported include:

• 'AES-CBC'
• 'AES-CTR'
• 'AES-GCM'
• 'AES-OCB'⁴
• 'ChaCha20-Poly1305'⁴
• 'RSA-OAEP'

subtle.exportKey(format, key)

• format <string> Must be one of 'raw', 'pkcs8', 'spki', 'jwk', 'raw-secret'⁴, 'raw-public'⁴, or 'raw-seed'⁴.
• key <CryptoKey>
• Returns: <Promise> Fulfills with an <ArrayBuffer> | <Object> upon success.

Exports the given key into the specified format, if supported.

If the <CryptoKey> is not extractable, the returned promise will reject.

When format is either 'pkcs8' or 'spki' and the export is successful, the returned promise will be resolved with an <ArrayBuffer> containing the exported key data.

When format is 'jwk' and the export is successful, the returned promise will be resolved with a JavaScript object conforming to the JSON Web Key specification.

subtle.getPublicKey(key, keyUsages)

• key <CryptoKey> A private key from which to derive the corresponding public key.
• keyUsages <string[]> See Key usages.
• Returns: <Promise> Fulfills with a <CryptoKey> upon success.

Derives the public key from a given private key.

subtle.generateKey(algorithm, extractable, keyUsages)

• algorithm <string> | <Algorithm> | <RsaHashedKeyGenParams> | <EcKeyGenParams> | <HmacKeyGenParams> | <AesKeyGenParams>

• extractable <boolean>
• keyUsages <string[]> See Key usages.
• Returns: <Promise> Fulfills with a <CryptoKey> | <CryptoKeyPair> upon success.

Using the parameters provided in algorithm, this method attempts to generate new keying material. Depending on the algorithm used either a single <CryptoKey> or a <CryptoKeyPair> is generated.

The <CryptoKeyPair> (public and private key) generating algorithms supported include:

• 'ECDH'
• 'ECDSA'
• 'Ed25519'
• 'Ed448'⁵
• 'ML-DSA-44'⁴
• 'ML-DSA-65'⁴
• 'ML-DSA-87'⁴
• 'ML-KEM-512'⁴
• 'ML-KEM-768'⁴
• 'ML-KEM-1024'⁴
• 'RSA-OAEP'
• 'RSA-PSS'
• 'RSASSA-PKCS1-v1_5'
• 'X25519'
• 'X448'⁵

The <CryptoKey> (secret key) generating algorithms supported include:

• 'AES-CBC'
• 'AES-CTR'
• 'AES-GCM'
• 'AES-KW'
• 'AES-OCB'⁴
• 'ChaCha20-Poly1305'⁴
• 'HMAC'
• 'KMAC128'⁴
• 'KMAC256'⁴

subtle.importKey(format, keyData, algorithm, extractable, keyUsages)

• format <string> Must be one of 'raw', 'pkcs8', 'spki', 'jwk', 'raw-secret'⁴, 'raw-public'⁴, or 'raw-seed'⁴.
• keyData <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer> | <Object>

• algorithm <string> | <Algorithm> | <RsaHashedImportParams> | <EcKeyImportParams> | <HmacImportParams>

• extractable <boolean>
• keyUsages <string[]> See Key usages.
• Returns: <Promise> Fulfills with a <CryptoKey> upon success.

This method attempts to interpret the provided keyData as the given format to create a <CryptoKey> instance using the provided algorithm, extractable, and keyUsages arguments. If the import is successful, the returned promise will be resolved with a <CryptoKey> representation of the key material.

If importing KDF algorithm keys, extractable must be false.

The algorithms currently supported include:

subtle.sign(algorithm, key, data)

• algorithm <string> | <Algorithm> | <RsaPssParams> | <EcdsaParams>
• key <CryptoKey>
• data <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>
• Returns: <Promise> Fulfills with an <ArrayBuffer> upon success.

Using the method and parameters given by algorithm and the keying material provided by key, this method attempts to generate a cryptographic signature of data. If successful, the returned promise is resolved with an <ArrayBuffer> containing the generated signature.

The algorithms currently supported include:

• 'ECDSA'
• 'Ed25519'
• 'Ed448'⁵
• 'HMAC'
• 'KMAC128'⁴
• 'KMAC256'⁴
• 'ML-DSA-44'⁴
• 'ML-DSA-65'⁴
• 'ML-DSA-87'⁴
• 'RSA-PSS'
• 'RSASSA-PKCS1-v1_5'

subtle.unwrapKey(format, wrappedKey, unwrappingKey, unwrapAlgo, unwrappedKeyAlgo, extractable, keyUsages)

• format <string> Must be one of 'raw', 'pkcs8', 'spki', 'jwk', 'raw-secret'⁴, 'raw-public'⁴, or 'raw-seed'⁴.
• wrappedKey <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>
• unwrappingKey <CryptoKey>

• unwrapAlgo <string> | <Algorithm> | <RsaOaepParams> | <AesCtrParams> | <AesCbcParams>
• unwrappedKeyAlgo <string> | <Algorithm> | <RsaHashedImportParams> | <EcKeyImportParams> | <HmacImportParams>

• extractable <boolean>
• keyUsages <string[]> See Key usages.
• Returns: <Promise> Fulfills with a <CryptoKey> upon success.

In cryptography, "wrapping a key" refers to exporting and then encrypting the keying material. This method attempts to decrypt a wrapped key and create a <CryptoKey> instance. It is equivalent to calling subtle.decrypt() first on the encrypted key data (using the wrappedKey, unwrapAlgo, and unwrappingKey arguments as input) then passing the results to the subtle.importKey() method using the unwrappedKeyAlgo, extractable, and keyUsages arguments as inputs. If successful, the returned promise is resolved with a <CryptoKey> object.

The wrapping algorithms currently supported include:

• 'AES-CBC'
• 'AES-CTR'
• 'AES-GCM'
• 'AES-KW'
• 'AES-OCB'⁴
• 'ChaCha20-Poly1305'⁴
• 'RSA-OAEP'

The unwrapped key algorithms supported include:

• 'AES-CBC'
• 'AES-CTR'
• 'AES-GCM'
• 'AES-KW'
• 'AES-OCB'⁴
• 'ChaCha20-Poly1305'⁴
• 'ECDH'
• 'ECDSA'
• 'Ed25519'
• 'Ed448'⁵
• 'HMAC'
• 'KMAC128'⁵
• 'KMAC256'⁵
• 'ML-DSA-44'⁴
• 'ML-DSA-65'⁴
• 'ML-DSA-87'⁴
• 'ML-KEM-512'⁴
• 'ML-KEM-768'⁴
• 'ML-KEM-1024'⁴v
• 'RSA-OAEP'
• 'RSA-PSS'
• 'RSASSA-PKCS1-v1_5'
• 'X25519'
• 'X448'⁵

subtle.verify(algorithm, key, signature, data)

• algorithm <string> | <Algorithm> | <RsaPssParams> | <EcdsaParams>
• key <CryptoKey>
• signature <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>
• data <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>
• Returns: <Promise> Fulfills with a <boolean> upon success.

Using the method and parameters given in algorithm and the keying material provided by key, this method attempts to verify that signature is a valid cryptographic signature of data. The returned promise is resolved with either true or false.

The algorithms currently supported include:

• 'ECDSA'
• 'Ed25519'
• 'Ed448'⁵
• 'HMAC'
• 'KMAC128'⁵
• 'KMAC256'⁵
• 'ML-DSA-44'⁴
• 'ML-DSA-65'⁴
• 'ML-DSA-87'⁴
• 'RSA-PSS'
• 'RSASSA-PKCS1-v1_5'

subtle.wrapKey(format, key, wrappingKey, wrapAlgo)

• format <string> Must be one of 'raw', 'pkcs8', 'spki', 'jwk', 'raw-secret'⁴, 'raw-public'⁴, or 'raw-seed'⁴.
• key <CryptoKey>
• wrappingKey <CryptoKey>
• wrapAlgo <string> | <Algorithm> | <RsaOaepParams> | <AesCtrParams> | <AesCbcParams>
• Returns: <Promise> Fulfills with an <ArrayBuffer> upon success.

In cryptography, "wrapping a key" refers to exporting and then encrypting the keying material. This method exports the keying material into the format identified by format, then encrypts it using the method and parameters specified by wrapAlgo and the keying material provided by wrappingKey. It is the equivalent to calling subtle.exportKey() using format and key as the arguments, then passing the result to the subtle.encrypt() method using wrappingKey and wrapAlgo as inputs. If successful, the returned promise will be resolved with an <ArrayBuffer> containing the encrypted key data.

The wrapping algorithms currently supported include:

• 'AES-CBC'
• 'AES-CTR'
• 'AES-GCM'
• 'AES-KW'
• 'AES-OCB'⁴
• 'ChaCha20-Poly1305'⁴
• 'RSA-OAEP'

Algorithm parameters

The algorithm parameter objects define the methods and parameters used by the various <SubtleCrypto> methods. While described here as "classes", they are simple JavaScript dictionary objects.

Class: Algorithm

Algorithm.name

• Type: <string>

Class: AeadParams

aeadParams.additionalData

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer> | <undefined>

Extra input that is not encrypted but is included in the authentication of the data. The use of additionalData is optional.

aeadParams.iv

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

The initialization vector must be unique for every encryption operation using a given key.

aeadParams.name

• Type: <string> Must be 'AES-GCM', 'AES-OCB', or 'ChaCha20-Poly1305'.

aeadParams.tagLength

• Type: <number> The size in bits of the generated authentication tag.

Class: AesDerivedKeyParams

aesDerivedKeyParams.name

• Type: <string> Must be one of 'AES-CBC', 'AES-CTR', 'AES-GCM', 'AES-OCB', or 'AES-KW'

aesDerivedKeyParams.length

• Type: <number>

The length of the AES key to be derived. This must be either 128, 192, or 256.

Class: AesCbcParams

aesCbcParams.iv

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

Provides the initialization vector. It must be exactly 16-bytes in length and should be unpredictable and cryptographically random.

aesCbcParams.name

• Type: <string> Must be 'AES-CBC'.

Class: AesCtrParams

aesCtrParams.counter

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

The initial value of the counter block. This must be exactly 16 bytes long.

The AES-CTR method uses the rightmost length bits of the block as the counter and the remaining bits as the nonce.

aesCtrParams.length

• Type: <number> The number of bits in the aesCtrParams.counter that are to be used as the counter.

aesCtrParams.name

• Type: <string> Must be 'AES-CTR'.

Class: AesKeyAlgorithm

aesKeyAlgorithm.length

• Type: <number>

The length of the AES key in bits.

aesKeyAlgorithm.name

• Type: <string>

Class: AesKeyGenParams

aesKeyGenParams.length

• Type: <number>

The length of the AES key to be generated. This must be either 128, 192, or 256.

aesKeyGenParams.name

• Type: <string> Must be one of 'AES-CBC', 'AES-CTR', 'AES-GCM', or 'AES-KW'

Class: Argon2Params

argon2Params.associatedData

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

Represents the optional associated data.

argon2Params.memory

• Type: <number>

Represents the memory size in kibibytes. It must be at least 8 times the degree of parallelism.

argon2Params.name

• Type: <string> Must be one of 'Argon2d', 'Argon2i', or 'Argon2id'.

argon2Params.nonce

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

Represents the nonce, which is a salt for password hashing applications.

argon2Params.parallelism

• Type: <number>

Represents the degree of parallelism.

argon2Params.passes

• Type: <number>

Represents the number of passes.

argon2Params.secretValue

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

Represents the optional secret value.

argon2Params.version

• Type: <number>

Represents the Argon2 version number. The default and currently only defined version is 19 (0x13).

Class: ContextParams

contextParams.name

• Type: <string> Must be Ed448⁵, 'ML-DSA-44'⁴, 'ML-DSA-65'⁴, or 'ML-DSA-87'⁴.

contextParams.context

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer> | <undefined>

The context member represents the optional context data to associate with the message.

Class: CShakeParams

cShakeParams.customization

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer> | <undefined>

The customization member represents the customization string. The Node.js Web Crypto API implementation only supports zero-length customization which is equivalent to not providing customization at all.

cShakeParams.functionName

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer> | <undefined>

The functionName member represents represents the function name, used by NIST to define functions based on cSHAKE. The Node.js Web Crypto API implementation only supports zero-length functionName which is equivalent to not providing functionName at all.

cShakeParams.length

• Type: <number> represents the requested output length in bits.

cShakeParams.name

• Type: <string> Must be 'cSHAKE128'⁴ or 'cSHAKE256'⁴

Class: EcdhKeyDeriveParams

ecdhKeyDeriveParams.name

• Type: <string> Must be 'ECDH', 'X25519', or 'X448'⁵.

ecdhKeyDeriveParams.public

• Type: <CryptoKey>

ECDH key derivation operates by taking as input one parties private key and another parties public key -- using both to generate a common shared secret. The ecdhKeyDeriveParams.public property is set to the other parties public key.

Class: EcdsaParams

ecdsaParams.hash

• Type: <string> | <Algorithm>

If represented as a <string>, the value must be one of:

• 'SHA-1'
• 'SHA-256'
• 'SHA-384'
• 'SHA-512'
• 'SHA3-256'⁴
• 'SHA3-384'⁴
• 'SHA3-512'⁴

If represented as an <Algorithm>, the object's name property must be one of the above listed values.

ecdsaParams.name

• Type: <string> Must be 'ECDSA'.

Class: EcKeyAlgorithm

ecKeyAlgorithm.name

• Type: <string>

ecKeyAlgorithm.namedCurve

• Type: <string>

Class: EcKeyGenParams

ecKeyGenParams.name

• Type: <string> Must be one of 'ECDSA' or 'ECDH'.

ecKeyGenParams.namedCurve

• Type: <string> Must be one of 'P-256', 'P-384', 'P-521'.

Class: EcKeyImportParams

ecKeyImportParams.name

• Type: <string> Must be one of 'ECDSA' or 'ECDH'.

ecKeyImportParams.namedCurve

• Type: <string> Must be one of 'P-256', 'P-384', 'P-521'.

Class: EncapsulatedBits

A temporary symmetric secret key (represented as <ArrayBuffer>) for message encryption and the ciphertext (that can be transmitted to the message recipient along with the message) encrypted by this shared key. The recipient uses their private key to determine what the shared key is which then allows them to decrypt the message.

encapsulatedBits.ciphertext

• Type: <ArrayBuffer>

encapsulatedBits.sharedKey

• Type: <ArrayBuffer>

Class: EncapsulatedKey

A temporary symmetric secret key (represented as <CryptoKey>) for message encryption and the ciphertext (that can be transmitted to the message recipient along with the message) encrypted by this shared key. The recipient uses their private key to determine what the shared key is which then allows them to decrypt the message.

encapsulatedKey.ciphertext

• Type: <ArrayBuffer>

encapsulatedKey.sharedKey

• Type: <CryptoKey>

Class: HkdfParams

hkdfParams.hash

• Type: <string> | <Algorithm>

If represented as a <string>, the value must be one of:

• 'SHA-1'
• 'SHA-256'
• 'SHA-384'
• 'SHA-512'
• 'SHA3-256'⁴
• 'SHA3-384'⁴
• 'SHA3-512'⁴

If represented as an <Algorithm>, the object's name property must be one of the above listed values.

hkdfParams.info

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

Provides application-specific contextual input to the HKDF algorithm. This can be zero-length but must be provided.

hkdfParams.name

• Type: <string> Must be 'HKDF'.

hkdfParams.salt

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

The salt value significantly improves the strength of the HKDF algorithm. It should be random or pseudorandom and should be the same length as the output of the digest function (for instance, if using 'SHA-256' as the digest, the salt should be 256-bits of random data).

Class: HmacImportParams

hmacImportParams.hash

• Type: <string> | <Algorithm>

If represented as a <string>, the value must be one of:

• 'SHA-1'
• 'SHA-256'
• 'SHA-384'
• 'SHA-512'
• 'SHA3-256'⁴
• 'SHA3-384'⁴
• 'SHA3-512'⁴

If represented as an <Algorithm>, the object's name property must be one of the above listed values.

hmacImportParams.length

• Type: <number>

The optional number of bits in the HMAC key. This is optional and should be omitted for most cases.

hmacImportParams.name

• Type: <string> Must be 'HMAC'.

Class: HmacKeyAlgorithm

hmacKeyAlgorithm.hash

• Type: <Algorithm>

hmacKeyAlgorithm.length

• Type: <number>

The length of the HMAC key in bits.

hmacKeyAlgorithm.name

• Type: <string>

Class: HmacKeyGenParams

hmacKeyGenParams.hash

• Type: <string> | <Algorithm>

If represented as a <string>, the value must be one of:

• 'SHA-1'
• 'SHA-256'
• 'SHA-384'
• 'SHA-512'
• 'SHA3-256'⁴
• 'SHA3-384'⁴
• 'SHA3-512'⁴

If represented as an <Algorithm>, the object's name property must be one of the above listed values.

hmacKeyGenParams.length

• Type: <number>

The number of bits to generate for the HMAC key. If omitted, the length will be determined by the hash algorithm used. This is optional and should be omitted for most cases.

hmacKeyGenParams.name

• Type: <string> Must be 'HMAC'.

Class: KeyAlgorithm

keyAlgorithm.name

• Type: <string>

Class: KmacImportParams

kmacImportParams.length

• Type: <number>

The optional number of bits in the KMAC key. This is optional and should be omitted for most cases.

kmacImportParams.name

• Type: <string> Must be 'KMAC128' or 'KMAC256'.

Class: KmacKeyAlgorithm

kmacKeyAlgorithm.length

• Type: <number>

The length of the KMAC key in bits.

kmacKeyAlgorithm.name

• Type: <string>

Class: KmacKeyGenParams

kmacKeyGenParams.length

• Type: <number>

The number of bits to generate for the KMAC key. If omitted, the length will be determined by the KMAC algorithm used. This is optional and should be omitted for most cases.

kmacKeyGenParams.name

• Type: <string> Must be 'KMAC128' or 'KMAC256'.

Class: KmacParams

kmacParams.algorithm

• Type: <string> Must be 'KMAC128' or 'KMAC256'.

kmacParams.customization

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer> | <undefined>

The customization member represents the optional customization string.

kmacParams.length

• Type: <number>

The length of the output in bytes. This must be a positive integer.

Class: Pbkdf2Params

pbkdf2Params.hash

• Type: <string> | <Algorithm>

If represented as a <string>, the value must be one of:

• 'SHA-1'
• 'SHA-256'
• 'SHA-384'
• 'SHA-512'
• 'SHA3-256'⁴
• 'SHA3-384'⁴
• 'SHA3-512'⁴

If represented as an <Algorithm>, the object's name property must be one of the above listed values.

pbkdf2Params.iterations

• Type: <number>

The number of iterations the PBKDF2 algorithm should make when deriving bits.

pbkdf2Params.name

• Type: <string> Must be 'PBKDF2'.

pbkdf2Params.salt

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

Should be at least 16 random or pseudorandom bytes.

Class: RsaHashedImportParams

rsaHashedImportParams.hash

• Type: <string> | <Algorithm>

If represented as a <string>, the value must be one of:

• 'SHA-1'
• 'SHA-256'
• 'SHA-384'
• 'SHA-512'
• 'SHA3-256'⁴
• 'SHA3-384'⁴
• 'SHA3-512'⁴

If represented as an <Algorithm>, the object's name property must be one of the above listed values.

rsaHashedImportParams.name

• Type: <string> Must be one of 'RSASSA-PKCS1-v1_5', 'RSA-PSS', or 'RSA-OAEP'.

Class: RsaHashedKeyAlgorithm

rsaHashedKeyAlgorithm.hash

• Type: <Algorithm>

rsaHashedKeyAlgorithm.modulusLength

• Type: <number>

The length in bits of the RSA modulus.

rsaHashedKeyAlgorithm.name

• Type: <string>

rsaHashedKeyAlgorithm.publicExponent

• Type: <Uint8Array>

The RSA public exponent.

Class: RsaHashedKeyGenParams

rsaHashedKeyGenParams.hash

• Type: <string> | <Algorithm>

If represented as a <string>, the value must be one of:

• 'SHA-1'
• 'SHA-256'
• 'SHA-384'
• 'SHA-512'
• 'SHA3-256'⁴
• 'SHA3-384'⁴
• 'SHA3-512'⁴

If represented as an <Algorithm>, the object's name property must be one of the above listed values.

rsaHashedKeyGenParams.modulusLength

• Type: <number>

The length in bits of the RSA modulus. As a best practice, this should be at least 2048.

rsaHashedKeyGenParams.name

• Type: <string> Must be one of 'RSASSA-PKCS1-v1_5', 'RSA-PSS', or 'RSA-OAEP'.

rsaHashedKeyGenParams.publicExponent

• Type: <Uint8Array>

The RSA public exponent. This must be a <Uint8Array> containing a big-endian, unsigned integer that must fit within 32-bits. The <Uint8Array> may contain an arbitrary number of leading zero-bits. The value must be a prime number. Unless there is reason to use a different value, use new Uint8Array([1, 0, 1]) (65537) as the public exponent.

Class: RsaOaepParams

rsaOaepParams.label

• Type: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer>

An additional collection of bytes that will not be encrypted, but will be bound to the generated ciphertext.

The rsaOaepParams.label parameter is optional.

rsaOaepParams.name

• Type: <string> must be 'RSA-OAEP'.

Class: RsaPssParams

rsaPssParams.name

• Type: <string> Must be 'RSA-PSS'.

rsaPssParams.saltLength

• Type: <number>

The length (in bytes) of the random salt to use.