Web Crypto API

Added in: v15.0.0

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

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

JScopy

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

JScopy

ECDSA key pairs

JScopy

Ed25519/Ed448/X25519/X448 key pairs

JScopy

HMAC keys

JScopy

RSA key pairs

JScopy

Encryption and decryption

JScopy

Exporting and importing keys

JScopy

Wrapping and unwrapping keys

JScopy

Sign and verify

JScopy

Deriving bits and keys

JScopy

Digest

JScopy

Algorithm matrix

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

C Crypto

Added in: v15.0.0

Calling require('node:crypto').webcrypto returns an instance of the Crypto class. Crypto is a singleton that provides access to the remainder of the crypto API.

M crypto.subtle

Added in: v15.0.0

• Type: SubtleCrypto

Provides access to the SubtleCrypto API.

M crypto.getRandomValues(typedArray)

Added in: v15.0.0

• 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.

M crypto.randomUUID()

Added in: v16.7.0

• Returns: string

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

C CryptoKey

Added in: v15.0.0

M cryptoKey.algorithm

Added in: v15.0.0

• Type: AesKeyGenParams | RsaHashedKeyGenParams | EcKeyGenParams | HmacKeyGenParams

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

Read-only.

M cryptoKey.extractable

Added in: v15.0.0

• Type: boolean

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

Read-only.

M cryptoKey.type

Added in: v15.0.0

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

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

M cryptoKey.usages

Added in: v15.0.0

• Type: string[]

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

The possible usages are:

• 'encrypt' - The key may be used to encrypt data.
• 'decrypt' - The key may be used to decrypt data.
• 'sign' - The key may be used to generate digital signatures.
• 'verify' - The key may be used to verify digital signatures.
• 'deriveKey' - The key may be used to derive a new key.
• 'deriveBits' - The key may be used to derive bits.
• 'wrapKey' - The key may be used to wrap another key.
• 'unwrapKey' - The key may be used to unwrap another key.

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

C CryptoKeyPair

Added in: v15.0.0

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

M cryptoKeyPair.privateKey

Added in: v15.0.0

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

M cryptoKeyPair.publicKey

Added in: v15.0.0

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

C SubtleCrypto

Added in: v15.0.0

M subtle.decrypt(algorithm, key, data)

Added in: v15.0.0

• algorithm: RsaOaepParams | AesCtrParams | AesCbcParams | AesGcmParams
• key: CryptoKey
• data: ArrayBuffer | TypedArray | DataView | Buffer
• Returns: Promise containing ArrayBuffer

Using the method and parameters specified in algorithm and the keying material provided by key, subtle.decrypt() 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:

• 'RSA-OAEP'
• 'AES-CTR'
• 'AES-CBC'
• 'AES-GCM'

M subtle.deriveBits(algorithm, baseKey, length)

• algorithm: AlgorithmIdentifier | EcdhKeyDeriveParams | HkdfParams | Pbkdf2Params
• baseKey: CryptoKey
• length: number
• Returns: Promise containing ArrayBuffer

Using the method and parameters specified in algorithm and the keying material provided by baseKey, subtle.deriveBits() attempts to generate length bits. The Node.js implementation requires that length is a multiple of 8. If successful, the returned promise will be resolved with an ArrayBuffer containing the generated data.

The algorithms currently supported include:

• 'ECDH'
• 'HKDF'
• 'PBKDF2'

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

• algorithm: AlgorithmIdentifier | EcdhKeyDeriveParams | HkdfParams | Pbkdf2Params
• baseKey: CryptoKey
• derivedKeyAlgorithm: HmacKeyGenParams | AesKeyGenParams
• extractable: boolean
• keyUsages: string[] See Key usages.
• Returns: Promise containing CryptoKey

Using the method and parameters specified in algorithm, and the keying material provided by baseKey, subtle.deriveKey() attempts to generate a new CryptoKey based on the method and parameters in derivedKeyAlgorithm.

Calling subtle.deriveKey() 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:

• 'ECDH'
• 'HKDF'
• 'PBKDF2'

M subtle.digest(algorithm, data)

Added in: v15.0.0

• algorithm: string | Object
• data: ArrayBuffer | TypedArray | DataView | Buffer
• Returns: Promise containing ArrayBuffer

Using the method identified by algorithm, subtle.digest() 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:

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

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

M subtle.encrypt(algorithm, key, data)

Added in: v15.0.0

• algorithm: RsaOaepParams | AesCtrParams | AesCbcParams | AesGcmParams
• key: CryptoKey
• Returns: Promise containing ArrayBuffer

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

The algorithms currently supported include:

• 'RSA-OAEP'
• 'AES-CTR'
• 'AES-CBC'
• 'AES-GCM'

M subtle.exportKey(format, key)

• format: string Must be one of 'raw', 'pkcs8', 'spki', or 'jwk'.
• key: CryptoKey
• Returns: Promise containing ArrayBuffer.

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.

M subtle.generateKey(algorithm, extractable, keyUsages)

Added in: v15.0.0

• algorithm: AlgorithmIdentifier | RsaHashedKeyGenParams | EcKeyGenParams | HmacKeyGenParams | AesKeyGenParams

• extractable: boolean

• keyUsages: string[] See Key usages.

• Returns: Promise containing CryptoKey | CryptoKeyPair

Using the method and parameters provided in algorithm, subtle.generateKey() attempts to generate new keying material. Depending the method used, the method may generate either a single CryptoKey or a CryptoKeyPair.

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

• 'RSASSA-PKCS1-v1_5'
• 'RSA-PSS'
• 'RSA-OAEP'
• 'ECDSA'
• 'Ed25519'¹
• 'Ed448'¹
• 'ECDH'
• 'X25519'¹
• 'X448'¹

The CryptoKey (secret key) generating algorithms supported include:

• 'HMAC'
• 'AES-CTR'
• 'AES-CBC'
• 'AES-GCM'
• 'AES-KW'

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

• format: string Must be one of 'raw', 'pkcs8', 'spki', or 'jwk'.

• keyData: ArrayBuffer | TypedArray | DataView | Buffer | KeyObject

• algorithm: AlgorithmIdentifier | RsaHashedImportParams | EcKeyImportParams | HmacImportParams

• extractable: boolean

• keyUsages: string[] See Key usages.

• Returns: Promise containing CryptoKey

The subtle.importKey() 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 the created CryptoKey.

If importing a 'PBKDF2' key, extractable must be false.

The algorithms currently supported include:

M subtle.sign(algorithm, key, data)

• algorithm: AlgorithmIdentifier | RsaPssParams | EcdsaParams | Ed448Params
• key: CryptoKey
• data: ArrayBuffer | TypedArray | DataView | Buffer
• Returns: Promise containing ArrayBuffer

Using the method and parameters given by algorithm and the keying material provided by key, subtle.sign() 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:

• 'RSASSA-PKCS1-v1_5'
• 'RSA-PSS'
• 'ECDSA'
• 'Ed25519'¹
• 'Ed448'¹
• 'HMAC'

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

Added in: v15.0.0

• format: string Must be one of 'raw', 'pkcs8', 'spki', or 'jwk'.

• wrappedKey: ArrayBuffer | TypedArray | DataView | Buffer

• unwrappingKey: CryptoKey

• unwrapAlgo: AlgorithmIdentifier | RsaOaepParams | AesCtrParams | AesCbcParams | AesGcmParams

• unwrappedKeyAlgo: AlgorithmIdentifier | RsaHashedImportParams | EcKeyImportParams | HmacImportParams

• extractable: boolean

• keyUsages: string[] See Key usages.

• Returns: Promise containing CryptoKey

In cryptography, "wrapping a key" refers to exporting and then encrypting the keying material. The subtle.unwrapKey() 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 in 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:

• 'RSA-OAEP'
• 'AES-CTR'
• 'AES-CBC'
• 'AES-GCM'
• 'AES-KW'

The unwrapped key algorithms supported include:

• 'RSASSA-PKCS1-v1_5'
• 'RSA-PSS'
• 'RSA-OAEP'
• 'ECDSA'
• 'ECDH'
• 'HMAC'
• 'AES-CTR'
• 'AES-CBC'
• 'AES-GCM'
• 'AES-KW'

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

• algorithm: AlgorithmIdentifier | RsaPssParams | EcdsaParams | Ed448Params
• key: CryptoKey
• signature: ArrayBuffer | TypedArray | DataView | Buffer
• data: ArrayBuffer | TypedArray | DataView | Buffer
• Returns: Promise containing boolean

Using the method and parameters given in algorithm and the keying material provided by key, subtle.verify() 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:

• 'RSASSA-PKCS1-v1_5'
• 'RSA-PSS'
• 'ECDSA'
• 'Ed25519'¹
• 'Ed448'¹
• 'HMAC'

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

Added in: v15.0.0

• format: string Must be one of 'raw', 'pkcs8', 'spki', or 'jwk'.
• key: CryptoKey
• wrappingKey: CryptoKey
• wrapAlgo: AlgorithmIdentifier | RsaOaepParams | AesCtrParams | AesCbcParams | AesGcmParams
• Returns: Promise containing ArrayBuffer

In cryptography, "wrapping a key" refers to exporting and then encrypting the keying material. The subtle.wrapKey() 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:

• 'RSA-OAEP'
• 'AES-CTR'
• 'AES-CBC'
• 'AES-GCM'
• 'AES-KW'

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.

C AlgorithmIdentifier

Added in: v16.17.0

M algorithmIdentifier.name

Added in: v16.17.0

• Type: string

C AesCbcParams

Added in: v15.0.0

M aesCbcParams.iv

Added in: v15.0.0

• Type: ArrayBuffer | TypedArray | DataView | Buffer

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

M aesCbcParams.name

Added in: v15.0.0

• Type: string Must be 'AES-CBC'.

C AesCtrParams

Added in: v15.0.0

M aesCtrParams.counter

Added in: v15.0.0

• 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.

M aesCtrParams.length

Added in: v15.0.0

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

M aesCtrParams.name

Added in: v15.0.0

• Type: string Must be 'AES-CTR'.

C AesGcmParams

Added in: v15.0.0

M aesGcmParams.additionalData

Added in: v15.0.0

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

With the AES-GCM method, the additionalData is extra input that is not encrypted but is included in the authentication of the data. The use of additionalData is optional.

M aesGcmParams.iv

Added in: v15.0.0

• Type: ArrayBuffer | TypedArray | DataView | Buffer

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

Ideally, this is a deterministic 12-byte value that is computed in such a way that it is guaranteed to be unique across all invocations that use the same key. Alternatively, the initialization vector may consist of at least 12 cryptographically random bytes. For more information on constructing initialization vectors for AES-GCM, refer to Section 8 of NIST SP 800-38D.

M aesGcmParams.name

Added in: v15.0.0

• Type: string Must be 'AES-GCM'.

M aesGcmParams.tagLength

Added in: v15.0.0

• Type: number The size in bits of the generated authentication tag. This values must be one of 32, 64, 96, 104, 112, 120, or 128. Default: 128.

C AesKeyGenParams

Added in: v15.0.0

M aesKeyGenParams.length

Added in: v15.0.0

• Type: number

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

M aesKeyGenParams.name

Added in: v15.0.0

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

C EcdhKeyDeriveParams

Added in: v15.0.0

M ecdhKeyDeriveParams.name

Added in: v15.0.0

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

M ecdhKeyDeriveParams.public

Added in: v15.0.0

• 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.

C EcdsaParams

Added in: v15.0.0

M ecdsaParams.hash

Added in: v15.0.0

• Type: string | Object

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

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

If represented as an Object, the object must have a name property whose value is one of the above listed values.

M ecdsaParams.name

Added in: v15.0.0

• Type: string Must be 'ECDSA'.

C EcKeyGenParams

Added in: v15.0.0

M ecKeyGenParams.name

Added in: v15.0.0

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

M ecKeyGenParams.namedCurve

Added in: v15.0.0

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

C EcKeyImportParams

Added in: v15.0.0

M ecKeyImportParams.name

Added in: v15.0.0

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

M ecKeyImportParams.namedCurve

Added in: v15.0.0

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

C Ed448Params

Added in: v15.0.0

M ed448Params.name

Added in: v16.17.0

• Type: string Must be 'Ed448'.

M ed448Params.context

Added in: v16.17.0

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

The context member represents the optional context data to associate with the message. The Node.js Web Crypto API implementation only supports zero-length context which is equivalent to not providing context at all.

C HkdfParams

Added in: v15.0.0

M hkdfParams.hash

Added in: v15.0.0

• Type: string | Object

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

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

If represented as an Object, the object must have a name property whose value is one of the above listed values.

M hkdfParams.info

Added in: v15.0.0

• Type: ArrayBuffer | TypedArray | DataView | Buffer

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

M hkdfParams.name

Added in: v15.0.0

• Type: string Must be 'HKDF'.

M hkdfParams.salt

Added in: v15.0.0

• 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).

C HmacImportParams

Added in: v15.0.0

M hmacImportParams.hash

Added in: v15.0.0

• Type: string | Object

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

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

If represented as an Object, the object must have a name property whose value is one of the above listed values.

M hmacImportParams.length

Added in: v15.0.0

• Type: number

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

M hmacImportParams.name

Added in: v15.0.0

• Type: string Must be 'HMAC'.

C HmacKeyGenParams

Added in: v15.0.0

M hmacKeyGenParams.hash

Added in: v15.0.0

• Type: string | Object

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

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

If represented as an Object, the object must have a name property whose value is one of the above listed values.

M hmacKeyGenParams.length

Added in: v15.0.0

• 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.

M hmacKeyGenParams.name

Added in: v15.0.0

• Type: string Must be 'HMAC'.

C Pbkdf2Params

Added in: v15.0.0

M pbkdb2Params.hash

Added in: v15.0.0

• Type: string | Object

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

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

If represented as an Object, the object must have a name property whose value is one of the above listed values.

M pbkdf2Params.iterations

Added in: v15.0.0

• Type: number

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

M pbkdf2Params.name

Added in: v15.0.0

• Type: string Must be 'PBKDF2'.

M pbkdf2Params.salt

Added in: v15.0.0

• Type: ArrayBuffer | TypedArray | DataView | Buffer

Should be at least 16 random or pseudorandom bytes.

C RsaHashedImportParams

Added in: v15.0.0

M rsaHashedImportParams.hash

Added in: v15.0.0

• Type: string | Object

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

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

If represented as an Object, the object must have a name property whose value is one of the above listed values.

M rsaHashedImportParams.name

Added in: v15.0.0

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

C RsaHashedKeyGenParams

Added in: v15.0.0

M rsaHashedKeyGenParams.hash

Added in: v15.0.0

• Type: string | Object

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

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

If represented as an Object, the object must have a name property whose value is one of the above listed values.

M rsaHashedKeyGenParams.modulusLength

Added in: v15.0.0

• Type: number

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

M rsaHashedKeyGenParams.name

Added in: v15.0.0

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

M rsaHashedKeyGenParams.publicExponent

Added in: v15.0.0

• 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.

C RsaOaepParams

Added in: v15.0.0

rsaOaepParams.label

Added in: v15.0.0

• 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

Added in: v15.0.0

• Type: string must be 'RSA-OAEP'.

C RsaPssParams

Added in: v15.0.0

M rsaPssParams.name

Added in: v15.0.0

• Type: string Must be 'RSA-PSS'.

M rsaPssParams.saltLength

Added in: v15.0.0

• Type: number

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