# Crypto
- Stability: 2 - Unstable; API changes are being discussed for
- future versions. Breaking changes will be minimized. See below.
+ Stability: 2 - Stable
Use `require('crypto')` to access this module.
decipher, sign and verify methods.
-## crypto.setEngine(engine, [flags])
+## crypto.setEngine(engine[, flags])
Load and set engine for some/all OpenSSL functions (selected by flags).
-`engine` could be either an id or a path to the to the engine's shared library.
+`engine` could be either an id or a path to the engine's shared library.
`flags` is optional and has `ENGINE_METHOD_ALL` value by default. It could take
one of or mix of following flags (defined in `constants` module):
Example:
var ciphers = crypto.getCiphers();
- console.log(ciphers); // ['AES-128-CBC', 'AES-128-CBC-HMAC-SHA1', ...]
+ console.log(ciphers); // ['aes-128-cbc', 'aes-128-ccm', ...]
## crypto.getHashes()
console.log(hashes); // ['sha', 'sha1', 'sha1WithRSAEncryption', ...]
+## crypto.getCurves()
+
+Returns an array with the names of the supported elliptic curves.
+
+Example:
+
+ var curves = crypto.getCurves();
+ console.log(curves); // ['secp256k1', 'secp384r1', ...]
+
+
## crypto.createCredentials(details)
+ Stability: 0 - Deprecated: Use [tls.createSecureContext][] instead.
+
Creates a credentials object, with the optional details being a
dictionary with keys:
<http://www.openssl.org/docs/apps/ciphers.html#CIPHER_LIST_FORMAT>
for details on the format.
-If no 'ca' details are given, then node.js will use the default
+If no 'ca' details are given, then Node.js will use the default
publicly trusted list of CAs as given in
<http://mxr.mozilla.org/mozilla/source/security/nss/lib/ckfw/builtins/certdata.txt>.
Returned by `crypto.createHash`.
-### hash.update(data, [input_encoding])
+### hash.update(data[, input_encoding])
Updates the hash content with the given `data`, the encoding of which
is given in `input_encoding` and can be `'utf8'`, `'ascii'` or
-`'binary'`. If no encoding is provided and the input is a string an
+`'binary'`. If no encoding is provided, and the input is a string, an
encoding of `'binary'` is enforced. If `data` is a `Buffer` then
`input_encoding` is ignored.
It is a [stream](stream.html) that is both readable and writable. The
written data is used to compute the hash. Once the writable side of
-the stream is ended, use the `read()` method to get the computed hash
-digest. The legacy `update` and `digest` methods are also supported.
+the stream is ended, use the `read()` method to get the enciphered
+contents. The legacy `update` and `final` methods are also supported.
+
+Note: `createCipher` derives keys with the OpenSSL function [EVP_BytesToKey][]
+with the digest algorithm set to MD5, one iteration, and no salt. The lack of
+salt allows dictionary attacks as the same password always creates the same key.
+The low iteration count and non-cryptographically secure hash algorithm allow
+passwords to be tested very rapidly.
+
+In line with OpenSSL's recommendation to use pbkdf2 instead of EVP_BytesToKey it
+is recommended you derive a key and iv yourself with [crypto.pbkdf2][] and to
+then use [createCipheriv()][] to create the cipher stream.
## crypto.createCipheriv(algorithm, key, iv)
encrypted data on the readable side. The legacy `update` and `final`
methods are also supported.
-### cipher.update(data, [input_encoding], [output_encoding])
+### cipher.update(data[, input_encoding][, output_encoding])
Updates the cipher with `data`, the encoding of which is given in
`input_encoding` and can be `'utf8'`, `'ascii'` or `'binary'`. If no
has been computed from the given data. Should be called after
encryption has been completed using the `final` method!
+### cipher.setAAD(buffer)
+
+For authenticated encryption modes (currently supported: GCM), this
+method sets the value used for the additional authenticated data (AAD) input
+parameter.
+
## crypto.createDecipher(algorithm, password)
plain-text data on the the readable side. The legacy `update` and
`final` methods are also supported.
-### decipher.update(data, [input_encoding], [output_encoding])
+### decipher.update(data[, input_encoding][, output_encoding])
Updates the decipher with `data`, which is encoded in `'binary'`,
`'base64'` or `'hex'`. If no encoding is provided, then a buffer is
You can disable auto padding if the data has been encrypted without
standard block padding to prevent `decipher.final` from checking and
-removing it. Can only work if the input data's length is a multiple of
+removing it. This will only work if the input data's length is a multiple of
the ciphers block size. You must call this before streaming data to
`decipher.update`.
`final` will throw, thus indicating that the ciphertext should
be discarded due to failed authentication.
+### decipher.setAAD(buffer)
+
+For authenticated encryption modes (currently supported: GCM), this
+method sets the value used for the additional authenticated data (AAD) input
+parameter.
+
## crypto.createSign(algorithm)
Updates the sign object with data. This can be called many times
with new data as it is streamed.
-### sign.sign(private_key, [output_format])
+### sign.sign(private_key[, output_format])
Calculates the signature on all the updated data passed through the
sign.
Updates the verifier object with data. This can be called many times
with new data as it is streamed.
-### verifier.verify(object, signature, [signature_format])
+### verifier.verify(object, signature[, signature_format])
Verifies the signed data by using the `object` and `signature`.
`object` is a string containing a PEM encoded object, which can be
Note: `verifier` object can not be used after `verify()` method has been
called.
-## crypto.createDiffieHellman(prime_length)
+## crypto.createDiffieHellman(prime_length[, generator])
Creates a Diffie-Hellman key exchange object and generates a prime of
-the given bit length. The generator used is `2`.
+`prime_length` bits and using an optional specific numeric `generator`.
+If no `generator` is specified, then `2` is used.
-## crypto.createDiffieHellman(prime, [encoding])
+## crypto.createDiffieHellman(prime[, prime_encoding][, generator][, generator_encoding])
-Creates a Diffie-Hellman key exchange object using the supplied prime.
-The generator used is `2`. Encoding can be `'binary'`, `'hex'`, or
-`'base64'`. If no encoding is specified, then a buffer is expected.
+Creates a Diffie-Hellman key exchange object using the supplied `prime` and an
+optional specific `generator`.
+`generator` can be a number, string, or Buffer.
+If no `generator` is specified, then `2` is used.
+`prime_encoding` and `generator_encoding` can be `'binary'`, `'hex'`, or `'base64'`.
+If no `prime_encoding` is specified, then a Buffer is expected for `prime`.
+If no `generator_encoding` is specified, then a Buffer is expected for `generator`.
## Class: DiffieHellman
Returned by `crypto.createDiffieHellman`.
+### diffieHellman.verifyError
+
+A bit field containing any warnings and/or errors as a result of a check performed
+during initialization. The following values are valid for this property
+(defined in `constants` module):
+
+* `DH_CHECK_P_NOT_SAFE_PRIME`
+* `DH_CHECK_P_NOT_PRIME`
+* `DH_UNABLE_TO_CHECK_GENERATOR`
+* `DH_NOT_SUITABLE_GENERATOR`
+
### diffieHellman.generateKeys([encoding])
Generates private and public Diffie-Hellman key values, and returns
transferred to the other party. Encoding can be `'binary'`, `'hex'`,
or `'base64'`. If no encoding is provided, then a buffer is returned.
-### diffieHellman.computeSecret(other_public_key, [input_encoding], [output_encoding])
+### diffieHellman.computeSecret(other_public_key[, input_encoding][, output_encoding])
Computes the shared secret using `other_public_key` as the other
party's public key and returns the computed shared secret. Supplied
### diffieHellman.getGenerator([encoding])
-Returns the Diffie-Hellman prime in the specified encoding, which can
+Returns the Diffie-Hellman generator in the specified encoding, which can
be `'binary'`, `'hex'`, or `'base64'`. If no encoding is provided,
then a buffer is returned.
which can be `'binary'`, `'hex'`, or `'base64'`. If no encoding is
provided, then a buffer is returned.
-### diffieHellman.setPublicKey(public_key, [encoding])
+### diffieHellman.setPublicKey(public_key[, encoding])
Sets the Diffie-Hellman public key. Key encoding can be `'binary'`,
`'hex'` or `'base64'`. If no encoding is provided, then a buffer is
expected.
-### diffieHellman.setPrivateKey(private_key, [encoding])
+### diffieHellman.setPrivateKey(private_key[, encoding])
Sets the Diffie-Hellman private key. Key encoding can be `'binary'`,
`'hex'` or `'base64'`. If no encoding is provided, then a buffer is
/* alice_secret and bob_secret should be the same */
console.log(alice_secret == bob_secret);
-## crypto.pbkdf2(password, salt, iterations, keylen, callback)
+## crypto.createECDH(curve_name)
+
+Creates an Elliptic Curve (EC) Diffie-Hellman key exchange object using a
+predefined curve specified by the `curve_name` string. Use [getCurves()][] to
+obtain a list of available curve names. On recent releases,
+`openssl ecparam -list_curves` will also display the name and description of
+each available elliptic curve.
+
+## Class: ECDH
+
+The class for creating EC Diffie-Hellman key exchanges.
+
+Returned by `crypto.createECDH`.
+
+### ECDH.generateKeys([encoding[, format]])
+
+Generates private and public EC Diffie-Hellman key values, and returns
+the public key in the specified format and encoding. This key should be
+transferred to the other party.
+
+Format specifies point encoding and can be `'compressed'`, `'uncompressed'`, or
+`'hybrid'`. If no format is provided - the point will be returned in
+`'uncompressed'` format.
+
+Encoding can be `'binary'`, `'hex'`, or `'base64'`. If no encoding is provided,
+then a buffer is returned.
+
+### ECDH.computeSecret(other_public_key[, input_encoding][, output_encoding])
+
+Computes the shared secret using `other_public_key` as the other
+party's public key and returns the computed shared secret. Supplied
+key is interpreted using specified `input_encoding`, and secret is
+encoded using specified `output_encoding`. Encodings can be
+`'binary'`, `'hex'`, or `'base64'`. If the input encoding is not
+provided, then a buffer is expected.
+
+If no output encoding is given, then a buffer is returned.
+
+### ECDH.getPublicKey([encoding[, format]])
+
+Returns the EC Diffie-Hellman public key in the specified encoding and format.
+
+Format specifies point encoding and can be `'compressed'`, `'uncompressed'`, or
+`'hybrid'`. If no format is provided - the point will be returned in
+`'uncompressed'` format.
+
+Encoding can be `'binary'`, `'hex'`, or `'base64'`. If no encoding is provided,
+then a buffer is returned.
+
+### ECDH.getPrivateKey([encoding])
+
+Returns the EC Diffie-Hellman private key in the specified encoding,
+which can be `'binary'`, `'hex'`, or `'base64'`. If no encoding is
+provided, then a buffer is returned.
+
+### ECDH.setPublicKey(public_key[, encoding])
+
+Sets the EC Diffie-Hellman public key. Key encoding can be `'binary'`,
+`'hex'` or `'base64'`. If no encoding is provided, then a buffer is
+expected.
+
+### ECDH.setPrivateKey(private_key[, encoding])
+
+Sets the EC Diffie-Hellman private key. Key encoding can be `'binary'`,
+`'hex'` or `'base64'`. If no encoding is provided, then a buffer is
+expected.
+
+Example (obtaining a shared secret):
+
+ var crypto = require('crypto');
+ var alice = crypto.createECDH('secp256k1');
+ var bob = crypto.createECDH('secp256k1');
+
+ alice.generateKeys();
+ bob.generateKeys();
+
+ var alice_secret = alice.computeSecret(bob.getPublicKey(), null, 'hex');
+ var bob_secret = bob.computeSecret(alice.getPublicKey(), null, 'hex');
+
+ /* alice_secret and bob_secret should be the same */
+ console.log(alice_secret == bob_secret);
+
+## crypto.pbkdf2(password, salt, iterations, keylen[, digest], callback)
+
+Asynchronous PBKDF2 function. Applies the selected HMAC digest function
+(default: SHA1) to derive a key of the requested byte length from the password,
+salt and number of iterations. The callback gets two arguments:
+`(err, derivedKey)`.
+
+Example:
+
+ crypto.pbkdf2('secret', 'salt', 4096, 64, 'sha256', function(err, key) {
+ if (err)
+ throw err;
+ console.log(key.toString('hex')); // 'c5e478d...1469e50'
+ });
-Asynchronous PBKDF2 applies pseudorandom function HMAC-SHA1 to derive
-a key of given length from the given password, salt and iterations.
-The callback gets two arguments `(err, derivedKey)`.
+You can get a list of supported digest functions with
+[crypto.getHashes()](#crypto_crypto_gethashes).
-## crypto.pbkdf2Sync(password, salt, iterations, keylen)
+## crypto.pbkdf2Sync(password, salt, iterations, keylen[, digest])
Synchronous PBKDF2 function. Returns derivedKey or throws error.
-## crypto.randomBytes(size, [callback])
+## crypto.randomBytes(size[, callback])
Generates cryptographically strong pseudo-random data. Usage:
});
// sync
- try {
- var buf = crypto.randomBytes(256);
- console.log('Have %d bytes of random data: %s', buf.length, buf);
- } catch (ex) {
- // handle error
- // most likely, entropy sources are drained
- }
-
-NOTE: Will throw error or invoke callback with error, if there is not enough
-accumulated entropy to generate cryptographically strong data. In other words,
-`crypto.randomBytes` without callback will not block even if all entropy sources
-are drained.
-
-## crypto.pseudoRandomBytes(size, [callback])
+ const buf = crypto.randomBytes(256);
+ console.log('Have %d bytes of random data: %s', buf.length, buf);
-Generates *non*-cryptographically strong pseudo-random data. The data
-returned will be unique if it is sufficiently long, but is not
-necessarily unpredictable. For this reason, the output of this
-function should never be used where unpredictability is important,
-such as in the generation of encryption keys.
-
-Usage is otherwise identical to `crypto.randomBytes`.
+NOTE: This will block if there is insufficient entropy, although it should
+normally never take longer than a few milliseconds. The only time when this
+may conceivably block is right after boot, when the whole system is still
+low on entropy.
## Class: Certificate
Exports the encoded challenge associated with the SPKAC.
+## crypto.publicEncrypt(public_key, buffer)
+
+Encrypts `buffer` with `public_key`. Only RSA is currently supported.
+
+`public_key` can be an object or a string. If `public_key` is a string, it is
+treated as the key with no passphrase and will use `RSA_PKCS1_OAEP_PADDING`.
+Since RSA public keys may be derived from private keys you may pass a private
+key to this method.
+
+`public_key`:
+
+* `key` : A string holding the PEM encoded private key
+* `passphrase` : An optional string of passphrase for the private key
+* `padding` : An optional padding value, one of the following:
+ * `constants.RSA_NO_PADDING`
+ * `constants.RSA_PKCS1_PADDING`
+ * `constants.RSA_PKCS1_OAEP_PADDING`
+
+NOTE: All paddings are defined in `constants` module.
+
+## crypto.publicDecrypt(public_key, buffer)
+
+See above for details. Has the same API as `crypto.publicEncrypt`. Default
+padding is `RSA_PKCS1_PADDING`.
+
+## crypto.privateDecrypt(private_key, buffer)
+
+Decrypts `buffer` with `private_key`.
+
+`private_key` can be an object or a string. If `private_key` is a string, it is
+treated as the key with no passphrase and will use `RSA_PKCS1_OAEP_PADDING`.
+
+`private_key`:
+
+* `key` : A string holding the PEM encoded private key
+* `passphrase` : An optional string of passphrase for the private key
+* `padding` : An optional padding value, one of the following:
+ * `constants.RSA_NO_PADDING`
+ * `constants.RSA_PKCS1_PADDING`
+ * `constants.RSA_PKCS1_OAEP_PADDING`
+
+NOTE: All paddings are defined in `constants` module.
+
+## crypto.privateEncrypt(private_key, buffer)
+
+See above for details. Has the same API as `crypto.privateDecrypt`.
+Default padding is `RSA_PKCS1_PADDING`.
+
## crypto.DEFAULT_ENCODING
The default encoding to use for functions that can take either strings
## Recent API Changes
-The Crypto module was added to Node before there was the concept of a
+The Crypto module was added to Node.js before there was the concept of a
unified Stream API, and before there were Buffer objects for handling
binary data.
As such, the streaming classes don't have the typical methods found on
-other Node classes, and many methods accepted and returned
+other Node.js classes, and many methods accepted and returned
Binary-encoded strings by default rather than Buffers. This was
changed to use Buffers by default instead.
[createCipher()]: #crypto_crypto_createcipher_algorithm_password
[createCipheriv()]: #crypto_crypto_createcipheriv_algorithm_key_iv
-[crypto.createDiffieHellman()]: #crypto_crypto_creatediffiehellman_prime_encoding
+[getCurves()]: #crypto_crypto_getcurves
+[crypto.createDiffieHellman()]: #crypto_crypto_creatediffiehellman_prime_prime_encoding_generator_generator_encoding
+[tls.createSecureContext]: tls.html#tls_tls_createsecurecontext_details
[diffieHellman.setPublicKey()]: #crypto_diffiehellman_setpublickey_public_key_encoding
[RFC 2412]: http://www.rfc-editor.org/rfc/rfc2412.txt
[RFC 3526]: http://www.rfc-editor.org/rfc/rfc3526.txt
+[crypto.pbkdf2]: #crypto_crypto_pbkdf2_password_salt_iterations_keylen_digest_callback
+[EVP_BytesToKey]: https://www.openssl.org/docs/crypto/EVP_BytesToKey.html
projects / platform / upstream / nodejs.git / blobdiff