# 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.
-The crypto module requires OpenSSL to be available on the underlying platform.
-It offers a way of encapsulating secure credentials to be used as part
-of a secure HTTPS net or http connection.
+The crypto module offers a way of encapsulating secure credentials to be
+used as part of a secure HTTPS net or http connection.
+
+It also offers a set of wrappers for OpenSSL's hash, hmac, cipher,
+decipher, sign and verify methods.
+
+
+## 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 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):
+
+* `ENGINE_METHOD_RSA`
+* `ENGINE_METHOD_DSA`
+* `ENGINE_METHOD_DH`
+* `ENGINE_METHOD_RAND`
+* `ENGINE_METHOD_ECDH`
+* `ENGINE_METHOD_ECDSA`
+* `ENGINE_METHOD_CIPHERS`
+* `ENGINE_METHOD_DIGESTS`
+* `ENGINE_METHOD_STORE`
+* `ENGINE_METHOD_PKEY_METH`
+* `ENGINE_METHOD_PKEY_ASN1_METH`
+* `ENGINE_METHOD_ALL`
+* `ENGINE_METHOD_NONE`
+
+
+## crypto.getCiphers()
+
+Returns an array with the names of the supported ciphers.
+
+Example:
+
+ var ciphers = crypto.getCiphers();
+ console.log(ciphers); // ['aes-128-cbc', 'aes-128-ccm', ...]
+
+
+## crypto.getHashes()
+
+Returns an array with the names of the supported hash algorithms.
+
+Example:
+
+ var hashes = 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', ...]
-It also offers a set of wrappers for OpenSSL's hash, hmac, cipher, decipher, sign and verify methods.
## crypto.createCredentials(details)
-Creates a credentials object, with the optional details being a dictionary with keys:
+ Stability: 0 - Deprecated: Use [tls.createSecureContext][] instead.
-* `pfx` : A string or buffer holding the PFX or PKCS12 encoded private key, certificate and CA certificates
+Creates a credentials object, with the optional details being a
+dictionary with keys:
+
+* `pfx` : A string or buffer holding the PFX or PKCS12 encoded private
+ key, certificate and CA certificates
* `key` : A string holding the PEM encoded private key
* `passphrase` : A string of passphrase for the private key or pfx
* `cert` : A string holding the PEM encoded certificate
-* `ca` : Either a string or list of strings of PEM encoded CA certificates to trust.
-* `crl` : Either a string or list of strings of PEM encoded CRLs (Certificate Revocation List)
-* `ciphers`: A string describing the ciphers to use or exclude. Consult
- <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 publicly trusted list of CAs as given in
+* `ca` : Either a string or list of strings of PEM encoded CA
+ certificates to trust.
+* `crl` : Either a string or list of strings of PEM encoded CRLs
+ (Certificate Revocation List)
+* `ciphers`: A string describing the ciphers to use or exclude.
+ Consult
+ <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
+publicly trusted list of CAs as given in
<http://mxr.mozilla.org/mozilla/source/security/nss/lib/ckfw/builtins/certdata.txt>.
## crypto.createHash(algorithm)
-Creates and returns a hash object, a cryptographic hash with the given algorithm
-which can be used to generate hash digests.
+Creates and returns a hash object, a cryptographic hash with the given
+algorithm which can be used to generate hash digests.
-`algorithm` is dependent on the available algorithms supported by the version
-of OpenSSL on the platform. Examples are `'sha1'`, `'md5'`, `'sha256'`, `'sha512'`, etc.
-On recent releases, `openssl list-message-digest-algorithms` will display the available digest algorithms.
+`algorithm` is dependent on the available algorithms supported by the
+version of OpenSSL on the platform. Examples are `'sha1'`, `'md5'`,
+`'sha256'`, `'sha512'`, etc. On recent releases, `openssl
+list-message-digest-algorithms` will display the available digest
+algorithms.
Example: this program that takes the sha1 sum of a file
The class for creating hash digests of data.
+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.
+
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
+encoding of `'binary'` is enforced. If `data` is a `Buffer` then
+`input_encoding` is ignored.
-Updates the hash content with the given `data`, the encoding of which is given
-in `input_encoding` and can be `'utf8'`, `'ascii'` or `'binary'`.
-Defaults to `'binary'`.
This can be called many times with new data as it is streamed.
### hash.digest([encoding])
-Calculates the digest of all of the passed data to be hashed.
-The `encoding` can be `'hex'`, `'binary'` or `'base64'`.
-Defaults to `'binary'`.
+Calculates the digest of all of the passed data to be hashed. The
+`encoding` can be `'hex'`, `'binary'` or `'base64'`. If no encoding
+is provided, then a buffer is returned.
-Note: `hash` object can not be used after `digest()` method has been called.
+Note: `hash` object can not be used after `digest()` method has been
+called.
## crypto.createHmac(algorithm, key)
-Creates and returns a hmac object, a cryptographic hmac with the given algorithm and key.
+Creates and returns a hmac object, a cryptographic hmac with the given
+algorithm and key.
-`algorithm` is dependent on the available algorithms supported by OpenSSL - see createHash above.
-`key` is the hmac key to be used.
+It is a [stream](stream.html) that is both readable and writable. The
+written data is used to compute the hmac. Once the writable side of
+the stream is ended, use the `read()` method to get the computed
+digest. The legacy `update` and `digest` methods are also supported.
+
+`algorithm` is dependent on the available algorithms supported by
+OpenSSL - see createHash above. `key` is the hmac key to be used.
## Class: Hmac
### hmac.update(data)
-Update the hmac content with the given `data`.
-This can be called many times with new data as it is streamed.
+Update the hmac content with the given `data`. This can be called
+many times with new data as it is streamed.
### hmac.digest([encoding])
-Calculates the digest of all of the passed data to the hmac.
-The `encoding` can be `'hex'`, `'binary'` or `'base64'`.
-Defaults to `'binary'`.
+Calculates the digest of all of the passed data to the hmac. The
+`encoding` can be `'hex'`, `'binary'` or `'base64'`. If no encoding
+is provided, then a buffer is returned.
-Note: `hmac` object can not be used after `digest()` method been called.
+Note: `hmac` object can not be used after `digest()` method has been
+called.
## crypto.createCipher(algorithm, password)
-Creates and returns a cipher object, with the given algorithm and password.
+Creates and returns a cipher object, with the given algorithm and
+password.
-`algorithm` is dependent on OpenSSL, examples are `'aes192'`, etc.
-On recent releases, `openssl list-cipher-algorithms` will display the
-available cipher algorithms.
-`password` is used to derive key and IV, which must be a `'binary'` encoded
-string or a [buffer](buffer.html).
+`algorithm` is dependent on OpenSSL, examples are `'aes192'`, etc. On
+recent releases, `openssl list-cipher-algorithms` will display the
+available cipher algorithms. `password` is used to derive key and IV,
+which must be a `'binary'` encoded string or a [buffer](buffer.html).
+
+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 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)
-Creates and returns a cipher object, with the given algorithm, key and iv.
+Creates and returns a cipher object, with the given algorithm, key and
+iv.
-`algorithm` is the same as the argument to `createCipher()`.
-`key` is the raw key used by the algorithm.
-`iv` is an [initialization
+`algorithm` is the same as the argument to `createCipher()`. `key` is
+the raw key used by the algorithm. `iv` is an [initialization
vector](http://en.wikipedia.org/wiki/Initialization_vector).
-`key` and `iv` must be `'binary'` encoded strings or [buffers](buffer.html).
+`key` and `iv` must be `'binary'` encoded strings or
+[buffers](buffer.html).
## Class: Cipher
Returned by `crypto.createCipher` and `crypto.createCipheriv`.
-### cipher.update(data, [input_encoding], [output_encoding])
+Cipher objects are [streams](stream.html) that are both readable and
+writable. The written plain text data is used to produce the
+encrypted data on the readable side. The legacy `update` and `final`
+methods are also supported.
+
+### 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'`.
-Defaults to `'binary'`.
+`input_encoding` and can be `'utf8'`, `'ascii'` or `'binary'`. If no
+encoding is provided, then a buffer is expected.
+If `data` is a `Buffer` then `input_encoding` is ignored.
-The `output_encoding` specifies the output format of the enciphered data,
-and can be `'binary'`, `'base64'` or `'hex'`. Defaults to `'binary'`.
+The `output_encoding` specifies the output format of the enciphered
+data, and can be `'binary'`, `'base64'` or `'hex'`. If no encoding is
+provided, then a buffer is returned.
-Returns the enciphered contents, and can be called many times with new data as it is streamed.
+Returns the enciphered contents, and can be called many times with new
+data as it is streamed.
### cipher.final([output_encoding])
-Returns any remaining enciphered contents, with `output_encoding` being one of:
-`'binary'`, `'base64'` or `'hex'`. Defaults to `'binary'`.
+Returns any remaining enciphered contents, with `output_encoding`
+being one of: `'binary'`, `'base64'` or `'hex'`. If no encoding is
+provided, then a buffer is returned.
-Note: `cipher` object can not be used after `final()` method been called.
+Note: `cipher` object can not be used after `final()` method has been
+called.
### cipher.setAutoPadding(auto_padding=true)
-You can disable automatic padding of the input data to block size. If `auto_padding` is false,
-the length of the entire input data must be a multiple of the cipher's block size or `final` will fail.
-Useful for non-standard padding, e.g. using `0x0` instead of PKCS padding. You must call this before `cipher.final`.
+You can disable automatic padding of the input data to block size. If
+`auto_padding` is false, the length of the entire input data must be a
+multiple of the cipher's block size or `final` will fail. Useful for
+non-standard padding, e.g. using `0x0` instead of PKCS padding. You
+must call this before `cipher.final`.
+
+### cipher.getAuthTag()
+
+For authenticated encryption modes (currently supported: GCM), this
+method returns a `Buffer` that represents the _authentication tag_ that
+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)
-Creates and returns a decipher object, with the given algorithm and key.
-This is the mirror of the [createCipher()][] above.
+Creates and returns a decipher object, with the given algorithm and
+key. This is the mirror of the [createCipher()][] above.
## crypto.createDecipheriv(algorithm, key, iv)
-Creates and returns a decipher object, with the given algorithm, key and iv.
-This is the mirror of the [createCipheriv()][] above.
+Creates and returns a decipher object, with the given algorithm, key
+and iv. This is the mirror of the [createCipheriv()][] above.
## Class: Decipher
Returned by `crypto.createDecipher` and `crypto.createDecipheriv`.
-### decipher.update(data, [input_encoding], [output_encoding])
+Decipher objects are [streams](stream.html) that are both readable and
+writable. The written enciphered data is used to produce the
+plain-text data on the the readable side. The legacy `update` and
+`final` methods are also supported.
-Updates the decipher with `data`, which is encoded in `'binary'`, `'base64'`
-or `'hex'`. Defaults to `'binary'`.
+### decipher.update(data[, input_encoding][, output_encoding])
-The `output_decoding` specifies in what format to return the deciphered
-plaintext: `'binary'`, `'ascii'` or `'utf8'`. Defaults to `'binary'`.
+Updates the decipher with `data`, which is encoded in `'binary'`,
+`'base64'` or `'hex'`. If no encoding is provided, then a buffer is
+expected.
+If `data` is a `Buffer` then `input_encoding` is ignored.
+
+The `output_decoding` specifies in what format to return the
+deciphered plaintext: `'binary'`, `'ascii'` or `'utf8'`. If no
+encoding is provided, then a buffer is returned.
### decipher.final([output_encoding])
-Returns any remaining plaintext which is deciphered,
-with `output_encoding` being one of: `'binary'`, `'ascii'` or `'utf8'`.
-Defaults to `'binary'`.
+Returns any remaining plaintext which is deciphered, with
+`output_encoding` being one of: `'binary'`, `'ascii'` or `'utf8'`. If
+no encoding is provided, then a buffer is returned.
-Note: `decipher` object can not be used after `final()` method been called.
+Note: `decipher` object can not be used after `final()` method has been
+called.
### decipher.setAutoPadding(auto_padding=true)
-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 the
-ciphers block size. You must call this before streaming data to `decipher.update`.
+You can disable auto padding if the data has been encrypted without
+standard block padding to prevent `decipher.final` from checking and
+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`.
+
+### decipher.setAuthTag(buffer)
+
+For authenticated encryption modes (currently supported: GCM), this
+method must be used to pass in the received _authentication tag_.
+If no tag is provided or if the ciphertext has been tampered with,
+`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)
-Creates and returns a signing object, with the given algorithm.
-On recent OpenSSL releases, `openssl list-public-key-algorithms` will display
-the available signing algorithms. Examples are `'RSA-SHA256'`.
+Creates and returns a signing object, with the given algorithm. On
+recent OpenSSL releases, `openssl list-public-key-algorithms` will
+display the available signing algorithms. Examples are `'RSA-SHA256'`.
-## Class: Signer
+## Class: Sign
Class for generating signatures.
Returned by `crypto.createSign`.
-### signer.update(data)
+Sign objects are writable [streams](stream.html). The written data is
+used to generate the signature. Once all of the data has been
+written, the `sign` method will return the signature. The legacy
+`update` method is also supported.
-Updates the signer object with data.
-This can be called many times with new data as it is streamed.
+### sign.update(data)
+
+Updates the sign object with data. This can be called many times
+with new data as it is streamed.
-### signer.sign(private_key, [output_format])
+### sign.sign(private_key[, output_format])
-Calculates the signature on all the updated data passed through the signer.
-`private_key` is a string containing the PEM encoded private key for signing.
+Calculates the signature on all the updated data passed through the
+sign.
+
+`private_key` can be an object or a string. If `private_key` is a string, it is
+treated as the key with no passphrase.
+
+`private_key`:
+
+* `key` : A string holding the PEM encoded private key
+* `passphrase` : A string of passphrase for the private key
-Returns the signature in `output_format` which can be `'binary'`, `'hex'` or
-`'base64'`. Defaults to `'binary'`.
+Returns the signature in `output_format` which can be `'binary'`,
+`'hex'` or `'base64'`. If no encoding is provided, then a buffer is
+returned.
-Note: `signer` object can not be used after `sign()` method been called.
+Note: `sign` object can not be used after `sign()` method has been
+called.
## crypto.createVerify(algorithm)
Returned by `crypto.createVerify`.
+Verify objects are writable [streams](stream.html). The written data
+is used to validate against the supplied signature. Once all of the
+data has been written, the `verify` method will return true if the
+supplied signature is valid. The legacy `update` method is also
+supported.
+
### verifier.update(data)
-Updates the verifier object with data.
-This can be called many times with new data as it is streamed.
+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 one of RSA public key,
-DSA public key, or X.509 certificate. `signature` is the previously calculated
-signature for the data, in the `signature_format` which can be `'binary'`,
-`'hex'` or `'base64'`. Defaults to `'binary'`.
+Verifies the signed data by using the `object` and `signature`.
+`object` is a string containing a PEM encoded object, which can be
+one of RSA public key, DSA public key, or X.509 certificate.
+`signature` is the previously calculated signature for the data, in
+the `signature_format` which can be `'binary'`, `'hex'` or `'base64'`.
+If no encoding is specified, then a buffer is expected.
-Returns true or false depending on the validity of the signature for the data and public key.
+Returns true or false depending on the validity of the signature for
+the data and public key.
-Note: `verifier` object can not be used after `verify()` method been called.
+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`.
+Creates a Diffie-Hellman key exchange object and generates a prime of
+`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'`.
-Defaults to `'binary'`.
+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 the
-public key in the specified encoding. This key should be transferred to the
-other party. Encoding can be `'binary'`, `'hex'`, or `'base64'`.
-Defaults to `'binary'`.
+Generates private and public Diffie-Hellman key values, and returns
+the public key in the specified encoding. This key should be
+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
+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.
-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'`. The input encoding defaults to `'binary'`.
-If no output encoding is given, the input encoding is used as output encoding.
+If no output encoding is given, then a buffer is returned.
### diffieHellman.getPrime([encoding])
-Returns the Diffie-Hellman prime in the specified encoding, which can be
-`'binary'`, `'hex'`, or `'base64'`. Defaults to `'binary'`.
+Returns the Diffie-Hellman prime in the specified encoding, which can
+be `'binary'`, `'hex'`, or `'base64'`. If no encoding is provided,
+then a buffer is returned.
### diffieHellman.getGenerator([encoding])
-Returns the Diffie-Hellman prime in the specified encoding, which can be
-`'binary'`, `'hex'`, or `'base64'`. Defaults to `'binary'`.
+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.
### diffieHellman.getPublicKey([encoding])
-Returns the Diffie-Hellman public key in the specified encoding, which can
-be `'binary'`, `'hex'`, or `'base64'`. Defaults to `'binary'`.
+Returns the Diffie-Hellman public key in the specified encoding, which
+can be `'binary'`, `'hex'`, or `'base64'`. If no encoding is provided,
+then a buffer is returned.
### diffieHellman.getPrivateKey([encoding])
-Returns the Diffie-Hellman private key in the specified encoding, which can
-be `'binary'`, `'hex'`, or `'base64'`. Defaults to `'binary'`.
+Returns the 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.
-### diffieHellman.setPublicKey(public_key, [encoding])
+### diffieHellman.setPublicKey(public_key[, encoding])
-Sets the Diffie-Hellman public key. Key encoding can be `'binary'`, `'hex'`,
-or `'base64'`. Defaults to `'binary'`.
+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(public_key, [encoding])
+### diffieHellman.setPrivateKey(private_key[, encoding])
-Sets the Diffie-Hellman private key. Key encoding can be `'binary'`, `'hex'`,
-or `'base64'`. Defaults to `'binary'`.
+Sets the Diffie-Hellman private key. Key encoding can be `'binary'`,
+`'hex'` or `'base64'`. If no encoding is provided, then a buffer is
+expected.
## crypto.getDiffieHellman(group_name)
-Creates a predefined Diffie-Hellman key exchange object.
-The supported groups are: `'modp1'`, `'modp2'`, `'modp5'`
-(defined in [RFC 2412][])
-and `'modp14'`, `'modp15'`, `'modp16'`, `'modp17'`, `'modp18'`
-(defined in [RFC 3526][]).
-The returned object mimics the interface of objects created by
-[crypto.createDiffieHellman()][] above, but
-will not allow to change the keys (with
-[diffieHellman.setPublicKey()][] for example).
-The advantage of using this routine is that the parties don't have to
-generate nor exchange group modulus beforehand, saving both processor and
-communication time.
+Creates a predefined Diffie-Hellman key exchange object. The
+supported groups are: `'modp1'`, `'modp2'`, `'modp5'` (defined in [RFC
+2412][]) and `'modp14'`, `'modp15'`, `'modp16'`, `'modp17'`,
+`'modp18'` (defined in [RFC 3526][]). The returned object mimics the
+interface of objects created by [crypto.createDiffieHellman()][]
+above, but will not allow to change the keys (with
+[diffieHellman.setPublicKey()][] for example). The advantage of using
+this routine is that the parties don't have to generate nor exchange
+group modulus beforehand, saving both processor and communication
+time.
Example (obtaining a shared secret):
alice.generateKeys();
bob.generateKeys();
- var alice_secret = alice.computeSecret(bob.getPublicKey(), 'binary', 'hex');
- var bob_secret = bob.computeSecret(alice.getPublicKey(), 'binary', 'hex');
+ 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.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, callback)
+## crypto.pbkdf2(password, salt, iterations, keylen[, digest], callback)
-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)`.
+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)`.
-## crypto.randomBytes(size, [callback])
+Example:
+
+ crypto.pbkdf2('secret', 'salt', 4096, 64, 'sha256', function(err, key) {
+ if (err)
+ throw err;
+ console.log(key.toString('hex')); // 'c5e478d...1469e50'
+ });
+
+You can get a list of supported digest functions with
+[crypto.getHashes()](#crypto_crypto_gethashes).
+
+## crypto.pbkdf2Sync(password, salt, iterations, keylen[, digest])
+
+Synchronous PBKDF2 function. Returns derivedKey or throws error.
+
+## 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
- }
+ const buf = crypto.randomBytes(256);
+ console.log('Have %d bytes of random data: %s', buf.length, buf);
+
+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.
-## Proposed API Changes in Future Versions of Node
+## Class: Certificate
-The Crypto module was added to Node before there was the concept of a
+The class used for working with signed public key & challenges. The most
+common usage for this series of functions is when dealing with the `<keygen>`
+element. http://www.openssl.org/docs/apps/spkac.html
+
+Returned by `crypto.Certificate`.
+
+### Certificate.verifySpkac(spkac)
+
+Returns true of false based on the validity of the SPKAC.
+
+### Certificate.exportChallenge(spkac)
+
+Exports the encoded public key from the supplied SPKAC.
+
+### Certificate.exportPublicKey(spkac)
+
+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
+or buffers. The default value is `'buffer'`, which makes it default
+to using Buffer objects. This is here to make the crypto module more
+easily compatible with legacy programs that expected `'binary'` to be
+the default encoding.
+
+Note that new programs will probably expect buffers, so only use this
+as a temporary measure.
+
+## Recent API Changes
+
+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 accept and return Binary-encoded
-strings by default rather than Buffers.
+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.
-A future version of node will make Buffers the default data type.
-This will be a breaking change for some use cases, but not all.
+This is a breaking change for some use cases, but not all.
For example, if you currently use the default arguments to the Sign
class, and then pass the results to the Verify class, without ever
inspecting the data, then it will continue to work as before. Where
-you now get a binary string and then present the binary string to the
-Verify object, you'll get a Buffer, and present the Buffer to the
-Verify object.
+you once got a binary string and then presented the binary string to
+the Verify object, you'll now get a Buffer, and present the Buffer to
+the Verify object.
-However, if you are doing things with the string data that will not
+However, if you were doing things with the string data that will not
work properly on Buffers (such as, concatenating them, storing in
databases, etc.), or you are passing binary strings to the crypto
functions without an encoding argument, then you will need to start
providing encoding arguments to specify which encoding you'd like to
-use.
-
-Also, a Streaming API will be provided, but this will be done in such
-a way as to preserve the legacy API surface.
+use. To switch to the previous style of using binary strings by
+default, set the `crypto.DEFAULT_ENCODING` field to 'binary'. Note
+that new programs will probably expect buffers, so only use this as a
+temporary measure.
[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