{ "source": "doc/api/crypto.md", "modules": [ { "textRaw": "Crypto", "name": "crypto", "stability": 2, "stabilityText": "Stable", "desc": "
The crypto
module provides cryptographic functionality that includes a set of\nwrappers for OpenSSL's hash, HMAC, cipher, decipher, sign and verify functions.
Use require('crypto')
to access this module.
const crypto = require('crypto');\n\nconst secret = 'abcdefg';\nconst hash = crypto.createHmac('sha256', secret)\n .update('I love cupcakes')\n .digest('hex');\nconsole.log(hash);\n // Prints:\n // c0fa1bc00531bd78ef38c628449c5102aeabd49b5dc3a2a516ea6ea959d6658e\n
\n",
"classes": [
{
"textRaw": "Class: Certificate",
"type": "class",
"name": "Certificate",
"meta": {
"added": [
"v0.11.8"
]
},
"desc": "SPKAC is a Certificate Signing Request mechanism originally implemented by\nNetscape and now specified formally as part of HTML5's keygen
element.
The crypto
module provides the Certificate
class for working with SPKAC\ndata. The most common usage is handling output generated by the HTML5\n<keygen>
element. Node.js uses OpenSSL's SPKAC implementation internally.
Instances of the Certificate
class can be created using the new
keyword\nor by calling crypto.Certificate()
as a function:
const crypto = require('crypto');\n\nconst cert1 = new crypto.Certificate();\nconst cert2 = crypto.Certificate();\n
\n",
"signatures": [
{
"params": []
}
]
},
{
"textRaw": "certificate.exportChallenge(spkac)",
"type": "method",
"name": "exportChallenge",
"meta": {
"added": [
"v0.11.8"
]
},
"desc": "The spkac
data structure includes a public key and a challenge. The\ncertificate.exportChallenge()
returns the challenge component in the\nform of a Node.js Buffer
. The spkac
argument can be either a string\nor a Buffer
.
const cert = require('crypto').Certificate();\nconst spkac = getSpkacSomehow();\nconst challenge = cert.exportChallenge(spkac);\nconsole.log(challenge.toString('utf8'));\n // Prints the challenge as a UTF8 string\n
\n",
"signatures": [
{
"params": [
{
"name": "spkac"
}
]
}
]
},
{
"textRaw": "certificate.exportPublicKey(spkac)",
"type": "method",
"name": "exportPublicKey",
"meta": {
"added": [
"v0.11.8"
]
},
"desc": "The spkac
data structure includes a public key and a challenge. The\ncertificate.exportPublicKey()
returns the public key component in the\nform of a Node.js Buffer
. The spkac
argument can be either a string\nor a Buffer
.
const cert = require('crypto').Certificate();\nconst spkac = getSpkacSomehow();\nconst publicKey = cert.exportPublicKey(spkac);\nconsole.log(publicKey);\n // Prints the public key as <Buffer ...>\n
\n",
"signatures": [
{
"params": [
{
"name": "spkac"
}
]
}
]
},
{
"textRaw": "certificate.verifySpkac(spkac)",
"type": "method",
"name": "verifySpkac",
"meta": {
"added": [
"v0.11.8"
]
},
"desc": "Returns true
if the given spkac
data structure is valid, false
otherwise.\nThe spkac
argument must be a Node.js Buffer
.
const cert = require('crypto').Certificate();\nconst spkac = getSpkacSomehow();\nconsole.log(cert.verifySpkac(new Buffer(spkac)));\n // Prints true or false\n
\n",
"signatures": [
{
"params": [
{
"name": "spkac"
}
]
}
]
}
]
},
{
"textRaw": "Class: Cipher",
"type": "class",
"name": "Cipher",
"meta": {
"added": [
"v0.1.94"
]
},
"desc": "Instances of the Cipher
class are used to encrypt data. The class can be\nused in one of two ways:
cipher.update()
and cipher.final()
methods to produce\nthe encrypted data.The crypto.createCipher()
or crypto.createCipheriv()
methods are\nused to create Cipher
instances. Cipher
objects are not to be created\ndirectly using the new
keyword.
Example: Using Cipher
objects as streams:
const crypto = require('crypto');\nconst cipher = crypto.createCipher('aes192', 'a password');\n\nvar encrypted = '';\ncipher.on('readable', () => {\n var data = cipher.read();\n if (data)\n encrypted += data.toString('hex');\n});\ncipher.on('end', () => {\n console.log(encrypted);\n // Prints: ca981be48e90867604588e75d04feabb63cc007a8f8ad89b10616ed84d815504\n});\n\ncipher.write('some clear text data');\ncipher.end();\n
\nExample: Using Cipher
and piped streams:
const crypto = require('crypto');\nconst fs = require('fs');\nconst cipher = crypto.createCipher('aes192', 'a password');\n\nconst input = fs.createReadStream('test.js');\nconst output = fs.createWriteStream('test.enc');\n\ninput.pipe(cipher).pipe(output);\n
\nExample: Using the cipher.update()
and cipher.final()
methods:
const crypto = require('crypto');\nconst cipher = crypto.createCipher('aes192', 'a password');\n\nvar encrypted = cipher.update('some clear text data', 'utf8', 'hex');\nencrypted += cipher.final('hex');\nconsole.log(encrypted);\n // Prints: ca981be48e90867604588e75d04feabb63cc007a8f8ad89b10616ed84d815504\n
\n",
"methods": [
{
"textRaw": "cipher.final([output_encoding])",
"type": "method",
"name": "final",
"meta": {
"added": [
"v0.1.94"
]
},
"desc": "Returns any remaining enciphered contents. If output_encoding
\nparameter is one of 'binary'
, 'base64'
or 'hex'
, a string is returned.\nIf an output_encoding
is not provided, a Buffer
is returned.
Once the cipher.final()
method has been called, the Cipher
object can no\nlonger be used to encrypt data. Attempts to call cipher.final()
more than\nonce will result in an error being thrown.
When using an authenticated encryption mode (only GCM
is currently\nsupported), the cipher.setAAD()
method sets the value used for the\nadditional authenticated data (AAD) input parameter.
When using an authenticated encryption mode (only GCM
is currently\nsupported), the cipher.getAuthTag()
method returns a Buffer
containing\nthe authentication tag that has been computed from the given data.
The cipher.getAuthTag()
method should only be called after encryption has\nbeen completed using the cipher.final()
method.
When using block encryption algorithms, the Cipher
class will automatically\nadd padding to the input data to the appropriate block size. To disable the\ndefault padding call cipher.setAutoPadding(false)
.
When auto_padding
is false
, the length of the entire input data must be a\nmultiple of the cipher's block size or cipher.final()
will throw an Error.\nDisabling automatic padding is useful for non-standard padding, for instance\nusing 0x0
instead of PKCS padding.
The cipher.setAutoPadding()
method must be called before cipher.final()
.
Updates the cipher with data
. If the input_encoding
argument is given,\nit's value must be one of 'utf8'
, 'ascii'
, or 'binary'
and the data
\nargument is a string using the specified encoding. If the input_encoding
\nargument is not given, data
must be a Buffer
. If data
is a\nBuffer
then input_encoding
is ignored.
The output_encoding
specifies the output format of the enciphered\ndata, and can be 'binary'
, 'base64'
or 'hex'
. If the output_encoding
\nis specified, a string using the specified encoding is returned. If no\noutput_encoding
is provided, a Buffer
is returned.
The cipher.update()
method can be called multiple times with new data until\ncipher.final()
is called. Calling cipher.update()
after\ncipher.final()
will result in an error being thrown.
Instances of the Decipher
class are used to decrypt data. The class can be\nused in one of two ways:
decipher.update()
and decipher.final()
methods to\nproduce the unencrypted data.The crypto.createDecipher()
or crypto.createDecipheriv()
methods are\nused to create Decipher
instances. Decipher
objects are not to be created\ndirectly using the new
keyword.
Example: Using Decipher
objects as streams:
const crypto = require('crypto');\nconst decipher = crypto.createDecipher('aes192', 'a password');\n\nvar decrypted = '';\ndecipher.on('readable', () => {\n var data = decipher.read();\n if (data)\n decrypted += data.toString('utf8');\n});\ndecipher.on('end', () => {\n console.log(decrypted);\n // Prints: some clear text data\n});\n\nvar encrypted = 'ca981be48e90867604588e75d04feabb63cc007a8f8ad89b10616ed84d815504';\ndecipher.write(encrypted, 'hex');\ndecipher.end();\n
\nExample: Using Decipher
and piped streams:
const crypto = require('crypto');\nconst fs = require('fs');\nconst decipher = crypto.createDecipher('aes192', 'a password');\n\nconst input = fs.createReadStream('test.enc');\nconst output = fs.createWriteStream('test.js');\n\ninput.pipe(decipher).pipe(output);\n
\nExample: Using the decipher.update()
and decipher.final()
methods:
const crypto = require('crypto');\nconst decipher = crypto.createDecipher('aes192', 'a password');\n\nvar encrypted = 'ca981be48e90867604588e75d04feabb63cc007a8f8ad89b10616ed84d815504';\nvar decrypted = decipher.update(encrypted, 'hex', 'utf8');\ndecrypted += decipher.final('utf8');\nconsole.log(decrypted);\n // Prints: some clear text data\n
\n",
"methods": [
{
"textRaw": "decipher.final([output_encoding])",
"type": "method",
"name": "final",
"meta": {
"added": [
"v0.1.94"
]
},
"desc": "Returns any remaining deciphered contents. If output_encoding
\nparameter is one of 'binary'
, 'base64'
or 'hex'
, a string is returned.\nIf an output_encoding
is not provided, a Buffer
is returned.
Once the decipher.final()
method has been called, the Decipher
object can\nno longer be used to decrypt data. Attempts to call decipher.final()
more\nthan once will result in an error being thrown.
When using an authenticated encryption mode (only GCM
is currently\nsupported), the decipher.setAAD()
method sets the value used for the\nadditional authenticated data (AAD) input parameter.
When using an authenticated encryption mode (only GCM
is currently\nsupported), the decipher.setAuthTag()
method is used to pass in the\nreceived authentication tag. If no tag is provided, or if the cipher text\nhas been tampered with, decipher.final()
with throw, indicating that the\ncipher text should be discarded due to failed authentication.
When data has been encrypted without standard block padding, calling\ndecipher.setAutoPadding(false)
will disable automatic padding to prevent\ndecipher.final()
from checking for and removing padding.
Turning auto padding off will only work if the input data's length is a\nmultiple of the ciphers block size.
\nThe decipher.setAutoPadding()
method must be called before\ndecipher.update()
.
Updates the decipher with data
. If the input_encoding
argument is given,\nit's value must be one of 'binary'
, 'base64'
, or 'hex'
and the data
\nargument is a string using the specified encoding. If the input_encoding
\nargument is not given, data
must be a Buffer
. If data
is a\nBuffer
then input_encoding
is ignored.
The output_encoding
specifies the output format of the enciphered\ndata, and can be 'binary'
, 'ascii'
or 'utf8'
. If the output_encoding
\nis specified, a string using the specified encoding is returned. If no\noutput_encoding
is provided, a Buffer
is returned.
The decipher.update()
method can be called multiple times with new data until\ndecipher.final()
is called. Calling decipher.update()
after\ndecipher.final()
will result in an error being thrown.
The DiffieHellman
class is a utility for creating Diffie-Hellman key\nexchanges.
Instances of the DiffieHellman
class can be created using the\ncrypto.createDiffieHellman()
function.
const crypto = require('crypto');\nconst assert = require('assert');\n\n// Generate Alice's keys...\nconst alice = crypto.createDiffieHellman(2048);\nconst alice_key = alice.generateKeys();\n\n// Generate Bob's keys...\nconst bob = crypto.createDiffieHellman(alice.getPrime(), alice.getGenerator());\nconst bob_key = bob.generateKeys();\n\n// Exchange and generate the secret...\nconst alice_secret = alice.computeSecret(bob_key);\nconst bob_secret = bob.computeSecret(alice_key);\n\n// OK\nassert.equal(alice_secret.toString('hex'), bob_secret.toString('hex'));\n
\n",
"methods": [
{
"textRaw": "diffieHellman.computeSecret(other_public_key[, input_encoding][, output_encoding])",
"type": "method",
"name": "computeSecret",
"meta": {
"added": [
"v0.5.0"
]
},
"desc": "Computes the shared secret using other_public_key
as the other\nparty's public key and returns the computed shared secret. The supplied\nkey is interpreted using the specified input_encoding
, and secret is\nencoded using specified output_encoding
. Encodings can be\n'binary'
, 'hex'
, or 'base64'
. If the input_encoding
is not\nprovided, other_public_key
is expected to be a Buffer
.
If output_encoding
is given a string is returned; otherwise, a\nBuffer
is returned.
Generates private and public Diffie-Hellman key values, and returns\nthe public key in the specified encoding
. This key should be\ntransferred to the other party. Encoding can be 'binary'
, 'hex'
,\nor 'base64'
. If encoding
is provided a string is returned; otherwise a\nBuffer
is returned.
Returns the Diffie-Hellman generator in the specified encoding
, which can\nbe 'binary'
, 'hex'
, or 'base64'
. If encoding
is provided a string is\nreturned; otherwise a Buffer
is returned.
Returns the Diffie-Hellman prime in the specified encoding
, which can\nbe 'binary'
, 'hex'
, or 'base64'
. If encoding
is provided a string is\nreturned; otherwise a Buffer
is returned.
Returns the Diffie-Hellman private key in the specified encoding
,\nwhich can be 'binary'
, 'hex'
, or 'base64'
. If encoding
is provided a\nstring is returned; otherwise a Buffer
is returned.
Returns the Diffie-Hellman public key in the specified encoding
, which\ncan be 'binary'
, 'hex'
, or 'base64'
. If encoding
is provided a\nstring is returned; otherwise a Buffer
is returned.
Sets the Diffie-Hellman private key. If the encoding
argument is provided\nand is either 'binary'
, 'hex'
, or 'base64'
, private_key
is expected\nto be a string. If no encoding
is provided, private_key
is expected\nto be a Buffer
.
Sets the Diffie-Hellman public key. If the encoding
argument is provided\nand is either 'binary'
, 'hex'
or 'base64'
, public_key
is expected\nto be a string. If no encoding
is provided, public_key
is expected\nto be a Buffer
.
A bit field containing any warnings and/or errors resulting from a check\nperformed during initialization of the DiffieHellman
object.
The following values are valid for this property (as defined in constants
\nmodule):
DH_CHECK_P_NOT_SAFE_PRIME
DH_CHECK_P_NOT_PRIME
DH_UNABLE_TO_CHECK_GENERATOR
DH_NOT_SUITABLE_GENERATOR
The ECDH
class is a utility for creating Elliptic Curve Diffie-Hellman (ECDH)\nkey exchanges.
Instances of the ECDH
class can be created using the\ncrypto.createECDH()
function.
const crypto = require('crypto');\nconst assert = require('assert');\n\n// Generate Alice's keys...\nconst alice = crypto.createECDH('secp521r1');\nconst alice_key = alice.generateKeys();\n\n// Generate Bob's keys...\nconst bob = crypto.createECDH('secp521r1');\nconst bob_key = bob.generateKeys();\n\n// Exchange and generate the secret...\nconst alice_secret = alice.computeSecret(bob_key);\nconst bob_secret = bob.computeSecret(alice_key);\n\nassert(alice_secret, bob_secret);\n // OK\n
\n",
"methods": [
{
"textRaw": "ecdh.computeSecret(other_public_key[, input_encoding][, output_encoding])",
"type": "method",
"name": "computeSecret",
"meta": {
"added": [
"v0.11.14"
]
},
"desc": "Computes the shared secret using other_public_key
as the other\nparty's public key and returns the computed shared secret. The supplied\nkey is interpreted using specified input_encoding
, and the returned secret\nis encoded using the specified output_encoding
. Encodings can be\n'binary'
, 'hex'
, or 'base64'
. If the input_encoding
is not\nprovided, other_public_key
is expected to be a Buffer
.
If output_encoding
is given a string will be returned; otherwise a\nBuffer
is returned.
Generates private and public EC Diffie-Hellman key values, and returns\nthe public key in the specified format
and encoding
. This key should be\ntransferred to the other party.
The format
arguments specifies point encoding and can be 'compressed'
,\n'uncompressed'
, or 'hybrid'
. If format
is not specified, the point will\nbe returned in 'uncompressed'
format.
The encoding
argument can be 'binary'
, 'hex'
, or 'base64'
. If\nencoding
is provided a string is returned; otherwise a Buffer
\nis returned.
Returns the EC Diffie-Hellman private key in the specified encoding
,\nwhich can be 'binary'
, 'hex'
, or 'base64'
. If encoding
is provided\na string is returned; otherwise a Buffer
is returned.
Returns the EC Diffie-Hellman public key in the specified encoding
and\nformat
.
The format
argument specifies point encoding and can be 'compressed'
,\n'uncompressed'
, or 'hybrid'
. If format
is not specified the point will be\nreturned in 'uncompressed'
format.
The encoding
argument can be 'binary'
, 'hex'
, or 'base64'
. If\nencoding
is specified, a string is returned; otherwise a Buffer
is\nreturned.
Sets the EC Diffie-Hellman private key. The encoding
can be 'binary'
,\n'hex'
or 'base64'
. If encoding
is provided, private_key
is expected\nto be a string; otherwise private_key
is expected to be a Buffer
. If\nprivate_key
is not valid for the curve specified when the ECDH
object was\ncreated, an error is thrown. Upon setting the private key, the associated\npublic point (key) is also generated and set in the ECDH object.
Sets the EC Diffie-Hellman public key. Key encoding can be 'binary'
,\n'hex'
or 'base64'
. If encoding
is provided public_key
is expected to\nbe a string; otherwise a Buffer
is expected.
Note that there is not normally a reason to call this method because ECDH
\nonly requires a private key and the other party's public key to compute the\nshared secret. Typically either ecdh.generateKeys()
or\necdh.setPrivateKey()
will be called. The ecdh.setPrivateKey()
method\nattempts to generate the public point/key associated with the private key being\nset.
Example (obtaining a shared secret):
\nconst crypto = require('crypto');\nconst alice = crypto.createECDH('secp256k1');\nconst bob = crypto.createECDH('secp256k1');\n\n// Note: This is a shortcut way to specify one of Alice's previous private\n// keys. It would be unwise to use such a predictable private key in a real\n// application.\nalice.setPrivateKey(\n crypto.createHash('sha256').update('alice', 'utf8').digest()\n);\n\n// Bob uses a newly generated cryptographically strong\n// pseudorandom key pair bob.generateKeys();\n\nconst alice_secret = alice.computeSecret(bob.getPublicKey(), null, 'hex');\nconst bob_secret = bob.computeSecret(alice.getPublicKey(), null, 'hex');\n\n// alice_secret and bob_secret should be the same shared secret value\nconsole.log(alice_secret === bob_secret);\n
\n",
"signatures": [
{
"params": [
{
"name": "public_key"
},
{
"name": "encoding",
"optional": true
}
]
}
]
}
]
},
{
"textRaw": "Class: Hash",
"type": "class",
"name": "Hash",
"meta": {
"added": [
"v0.1.92"
]
},
"desc": "The Hash
class is a utility for creating hash digests of data. It can be\nused in one of two ways:
hash.update()
and hash.digest()
methods to produce the\ncomputed hash.The crypto.createHash()
method is used to create Hash
instances. Hash
\nobjects are not to be created directly using the new
keyword.
Example: Using Hash
objects as streams:
const crypto = require('crypto');\nconst hash = crypto.createHash('sha256');\n\nhash.on('readable', () => {\n var data = hash.read();\n if (data)\n console.log(data.toString('hex'));\n // Prints:\n // 6a2da20943931e9834fc12cfe5bb47bbd9ae43489a30726962b576f4e3993e50\n});\n\nhash.write('some data to hash');\nhash.end();\n
\nExample: Using Hash
and piped streams:
const crypto = require('crypto');\nconst fs = require('fs');\nconst hash = crypto.createHash('sha256');\n\nconst input = fs.createReadStream('test.js');\ninput.pipe(hash).pipe(process.stdout);\n
\nExample: Using the hash.update()
and hash.digest()
methods:
const crypto = require('crypto');\nconst hash = crypto.createHash('sha256');\n\nhash.update('some data to hash');\nconsole.log(hash.digest('hex'));\n // Prints:\n // 6a2da20943931e9834fc12cfe5bb47bbd9ae43489a30726962b576f4e3993e50\n
\n",
"methods": [
{
"textRaw": "hash.digest([encoding])",
"type": "method",
"name": "digest",
"meta": {
"added": [
"v0.1.92"
]
},
"desc": "Calculates the digest of all of the data passed to be hashed (using the\nhash.update()
method). The encoding
can be 'hex'
, 'binary'
or\n'base64'
. If encoding
is provided a string will be returned; otherwise\na Buffer
is returned.
The Hash
object can not be used again after hash.digest()
method has been\ncalled. Multiple calls will cause an error to be thrown.
Updates the hash content with the given data
, the encoding of which\nis given in input_encoding
and can be 'utf8'
, 'ascii'
or\n'binary'
. If encoding
is not provided, and the data
is a string, an\nencoding of 'binary'
is enforced. If data
is a Buffer
then\ninput_encoding
is ignored.
This can be called many times with new data as it is streamed.
\n", "signatures": [ { "params": [ { "name": "data" }, { "name": "input_encoding", "optional": true } ] } ] } ] }, { "textRaw": "Class: Hmac", "type": "class", "name": "Hmac", "meta": { "added": [ "v0.1.94" ] }, "desc": "The Hmac
Class is a utility for creating cryptographic HMAC digests. It can\nbe used in one of two ways:
hmac.update()
and hmac.digest()
methods to produce the\ncomputed HMAC digest.The crypto.createHmac()
method is used to create Hmac
instances. Hmac
\nobjects are not to be created directly using the new
keyword.
Example: Using Hmac
objects as streams:
const crypto = require('crypto');\nconst hmac = crypto.createHmac('sha256', 'a secret');\n\nhmac.on('readable', () => {\n var data = hmac.read();\n if (data)\n console.log(data.toString('hex'));\n // Prints:\n // 7fd04df92f636fd450bc841c9418e5825c17f33ad9c87c518115a45971f7f77e\n});\n\nhmac.write('some data to hash');\nhmac.end();\n
\nExample: Using Hmac
and piped streams:
const crypto = require('crypto');\nconst fs = require('fs');\nconst hmac = crypto.createHmac('sha256', 'a secret');\n\nconst input = fs.createReadStream('test.js');\ninput.pipe(hmac).pipe(process.stdout);\n
\nExample: Using the hmac.update()
and hmac.digest()
methods:
const crypto = require('crypto');\nconst hmac = crypto.createHmac('sha256', 'a secret');\n\nhmac.update('some data to hash');\nconsole.log(hmac.digest('hex'));\n // Prints:\n // 7fd04df92f636fd450bc841c9418e5825c17f33ad9c87c518115a45971f7f77e\n
\n",
"methods": [
{
"textRaw": "hmac.digest([encoding])",
"type": "method",
"name": "digest",
"meta": {
"added": [
"v0.1.94"
]
},
"desc": "Calculates the HMAC digest of all of the data passed using hmac.update()
.\nThe encoding
can be 'hex'
, 'binary'
or 'base64'
. If encoding
is\nprovided a string is returned; otherwise a Buffer
is returned;
The Hmac
object can not be used again after hmac.digest()
has been\ncalled. Multiple calls to hmac.digest()
will result in an error being thrown.
Updates the Hmac
content with the given data
, the encoding of which\nis given in input_encoding
and can be 'utf8'
, 'ascii'
or\n'binary'
. If encoding
is not provided, and the data
is a string, an\nencoding of 'utf8'
is enforced. If data
is a Buffer
then\ninput_encoding
is ignored.
This can be called many times with new data as it is streamed.
\n", "signatures": [ { "params": [ { "name": "data" }, { "name": "input_encoding", "optional": true } ] } ] } ] }, { "textRaw": "Class: Sign", "type": "class", "name": "Sign", "meta": { "added": [ "v0.1.92" ] }, "desc": "The Sign
Class is a utility for generating signatures. It can be used in one\nof two ways:
sign.sign()
method is used to generate and return the signature, orsign.update()
and sign.sign()
methods to produce the\nsignature.The crypto.createSign()
method is used to create Sign
instances. Sign
\nobjects are not to be created directly using the new
keyword.
Example: Using Sign
objects as streams:
const crypto = require('crypto');\nconst sign = crypto.createSign('RSA-SHA256');\n\nsign.write('some data to sign');\nsign.end();\n\nconst private_key = getPrivateKeySomehow();\nconsole.log(sign.sign(private_key, 'hex'));\n // Prints the calculated signature\n
\nExample: Using the sign.update()
and sign.sign()
methods:
const crypto = require('crypto');\nconst sign = crypto.createSign('RSA-SHA256');\n\nsign.update('some data to sign');\n\nconst private_key = getPrivateKeySomehow();\nconsole.log(sign.sign(private_key, 'hex'));\n // Prints the calculated signature\n
\nA Sign
instance can also be created by just passing in the digest\nalgorithm name, in which case OpenSSL will infer the full signature algorithm\nfrom the type of the PEM-formatted private key, including algorithms that\ndo not have directly exposed name constants, e.g. 'ecdsa-with-SHA256'.
Example: signing using ECDSA with SHA256
\nconst crypto = require('crypto');\nconst sign = crypto.createSign('sha256');\n\nsign.update('some data to sign');\n\nconst private_key = '-----BEGIN EC PRIVATE KEY-----\\n' +\n 'MHcCAQEEIF+jnWY1D5kbVYDNvxxo/Y+ku2uJPDwS0r/VuPZQrjjVoAoGCCqGSM49\\n' +\n 'AwEHoUQDQgAEurOxfSxmqIRYzJVagdZfMMSjRNNhB8i3mXyIMq704m2m52FdfKZ2\\n' +\n 'pQhByd5eyj3lgZ7m7jbchtdgyOF8Io/1ng==\\n' +\n '-----END EC PRIVATE KEY-----\\n';\n\nconsole.log(sign.sign(private_key).toString('hex'));\n
\n",
"methods": [
{
"textRaw": "sign.sign(private_key[, output_format])",
"type": "method",
"name": "sign",
"meta": {
"added": [
"v0.1.92"
]
},
"desc": "Calculates the signature on all the data passed through using either\nsign.update()
or sign.write()
.
The private_key
argument can be an object or a string. If private_key
is a\nstring, it is treated as a raw key with no passphrase. If private_key
is an\nobject, it is interpreted as a hash containing two properties:
key
: {String} - PEM encoded private keypassphrase
: {String} - passphrase for the private keyThe output_format
can specify one of 'binary'
, 'hex'
or 'base64'
. If\noutput_format
is provided a string is returned; otherwise a Buffer
is\nreturned.
The Sign
object can not be again used after sign.sign()
method has been\ncalled. Multiple calls to sign.sign()
will result in an error being thrown.
Updates the Sign
content with the given data
, the encoding of which\nis given in input_encoding
and can be 'utf8'
, 'ascii'
or\n'binary'
. If encoding
is not provided, and the data
is a string, an\nencoding of 'utf8'
is enforced. If data
is a Buffer
then\ninput_encoding
is ignored.
This can be called many times with new data as it is streamed.
\n", "signatures": [ { "params": [ { "name": "data" }, { "name": "input_encoding", "optional": true } ] } ] } ] }, { "textRaw": "Class: Verify", "type": "class", "name": "Verify", "meta": { "added": [ "v0.1.92" ] }, "desc": "The Verify
class is a utility for verifying signatures. It can be used in one\nof two ways:
verify.update()
and verify.verify()
methods to verify\nthe signature.The [crypto.createVerify()
][] method is used to create Verify
instances.\nVerify
objects are not to be created directly using the new
keyword.
Example: Using Verify
objects as streams:
const crypto = require('crypto');\nconst verify = crypto.createVerify('RSA-SHA256');\n\nverify.write('some data to sign');\nverify.end();\n\nconst public_key = getPublicKeySomehow();\nconst signature = getSignatureToVerify();\nconsole.log(verify.verify(public_key, signature));\n // Prints true or false\n
\nExample: Using the verify.update()
and verify.verify()
methods:
const crypto = require('crypto');\nconst verify = crypto.createVerify('RSA-SHA256');\n\nverify.update('some data to sign');\n\nconst public_key = getPublicKeySomehow();\nconst signature = getSignatureToVerify();\nconsole.log(verify.verify(public_key, signature));\n // Prints true or false\n
\n",
"methods": [
{
"textRaw": "verifier.update(data[, input_encoding])",
"type": "method",
"name": "update",
"meta": {
"added": [
"v0.1.92"
]
},
"desc": "Updates the Verify
content with the given data
, the encoding of which\nis given in input_encoding
and can be 'utf8'
, 'ascii'
or\n'binary'
. If encoding
is not provided, and the data
is a string, an\nencoding of 'utf8'
is enforced. If data
is a Buffer
then\ninput_encoding
is ignored.
This can be called many times with new data as it is streamed.
\n", "signatures": [ { "params": [ { "name": "data" }, { "name": "input_encoding", "optional": true } ] } ] }, { "textRaw": "verifier.verify(object, signature[, signature_format])", "type": "method", "name": "verify", "meta": { "added": [ "v0.1.92" ] }, "desc": "Verifies the provided data using the given object
and signature
.\nThe object
argument is a string containing a PEM encoded object, which can be\none an RSA public key, a DSA public key, or an X.509 certificate.\nThe signature
argument is the previously calculated signature for the data, in\nthe signature_format
which can be 'binary'
, 'hex'
or 'base64'
.\nIf a signature_format
is specified, the signature
is expected to be a\nstring; otherwise signature
is expected to be a Buffer
.
Returns true
or false
depending on the validity of the signature for\nthe data and public key.
The verifier
object can not be used again after verify.verify()
has been\ncalled. Multiple calls to verify.verify()
will result in an error being\nthrown.
The default encoding to use for functions that can take either strings\nor buffers. The default value is 'buffer'
, which makes methods\ndefault to Buffer
objects.
The crypto.DEFAULT_ENCODING
mechanism is provided for backwards compatibility\nwith legacy programs that expect 'binary'
to be the default encoding.
New applications should expect the default to be 'buffer'
. This property may\nbecome deprecated in a future Node.js release.
Creates and returns a Cipher
object that uses the given algorithm
and\npassword
.
The algorithm
is dependent on OpenSSL, examples are 'aes192'
, etc. On\nrecent OpenSSL releases, openssl list-cipher-algorithms
will display the\navailable cipher algorithms.
The password
is used to derive the cipher key and initialization vector (IV).\nThe value must be either a 'binary'
encoded string or a Buffer
.
The implementation of crypto.createCipher()
derives keys using the OpenSSL\nfunction EVP_BytesToKey
with the digest algorithm set to MD5, one\niteration, and no salt. The lack of salt allows dictionary attacks as the same\npassword always creates the same key. The low iteration count and\nnon-cryptographically secure hash algorithm allow passwords to be tested very\nrapidly.
In line with OpenSSL's recommendation to use pbkdf2 instead of\nEVP_BytesToKey
it is recommended that developers derive a key and IV on\ntheir own using crypto.pbkdf2()
and to use crypto.createCipheriv()
\nto create the Cipher
object.
Creates and returns a Cipher
object, with the given algorithm
, key
and\ninitialization vector (iv
).
The algorithm
is dependent on OpenSSL, examples are 'aes192'
, etc. On\nrecent OpenSSL releases, openssl list-cipher-algorithms
will display the\navailable cipher algorithms.
The key
is the raw key used by the algorithm
and iv
is an\ninitialization vector. Both arguments must be 'binary'
encoded strings or\nbuffers.
The crypto.createCredentials()
method is a deprecated alias for creating\nand returning a tls.SecureContext
object. The crypto.createCredentials()
\nmethod should not be used.
The optional details
argument is a hash object with keys:
pfx
: {String|Buffer} - PFX or PKCS12 encoded private\nkey, certificate and CA certificateskey
: {String} - PEM encoded private keypassphrase
: {String} - passphrase for the private key or PFXcert
: {String} - PEM encoded certificateca
: {String|Array} - Either a string or array of strings of PEM encoded CA\ncertificates to trust.crl
: {String|Array} - Either a string or array of strings of PEM encoded CRLs\n(Certificate Revocation List)ciphers
: {String} using the OpenSSL cipher list format describing the\ncipher algorithms to use or exclude.If no 'ca' details are given, Node.js will use Mozilla's default\npublicly trusted list of CAs.
\n", "signatures": [ { "params": [ { "name": "details" } ] } ] }, { "textRaw": "crypto.createDecipher(algorithm, password)", "type": "method", "name": "createDecipher", "meta": { "added": [ "v0.1.94" ] }, "desc": "Creates and returns a Decipher
object that uses the given algorithm
and\npassword
(key).
The implementation of crypto.createDecipher()
derives keys using the OpenSSL\nfunction EVP_BytesToKey
with the digest algorithm set to MD5, one\niteration, and no salt. The lack of salt allows dictionary attacks as the same\npassword always creates the same key. The low iteration count and\nnon-cryptographically secure hash algorithm allow passwords to be tested very\nrapidly.
In line with OpenSSL's recommendation to use pbkdf2 instead of\nEVP_BytesToKey
it is recommended that developers derive a key and IV on\ntheir own using crypto.pbkdf2()
and to use crypto.createDecipheriv()
\nto create the Decipher
object.
Creates and returns a Decipher
object that uses the given algorithm
, key
\nand initialization vector (iv
).
The algorithm
is dependent on OpenSSL, examples are 'aes192'
, etc. On\nrecent OpenSSL releases, openssl list-cipher-algorithms
will display the\navailable cipher algorithms.
The key
is the raw key used by the algorithm
and iv
is an\ninitialization vector. Both arguments must be 'binary'
encoded strings or\nbuffers.
Creates a DiffieHellman
key exchange object using the supplied prime
and an\noptional specific generator
.
The generator
argument can be a number, string, or Buffer
. If\ngenerator
is not specified, the value 2
is used.
The prime_encoding
and generator_encoding
arguments can be 'binary'
,\n'hex'
, or 'base64'
.
If prime_encoding
is specified, prime
is expected to be a string; otherwise\na Buffer
is expected.
If generator_encoding
is specified, generator
is expected to be a string;\notherwise either a number or Buffer
is expected.
Creates a DiffieHellman
key exchange object and generates a prime of\nprime_length
bits using an optional specific numeric generator
.\nIf generator
is not specified, the value 2
is used.
Creates an Elliptic Curve Diffie-Hellman (ECDH
) key exchange object using a\npredefined curve specified by the curve_name
string. Use\ncrypto.getCurves()
to obtain a list of available curve names. On recent\nOpenSSL releases, openssl ecparam -list_curves
will also display the name\nand description of each available elliptic curve.
Creates and returns a Hash
object that can be used to generate hash digests\nusing the given algorithm
.
The algorithm
is dependent on the available algorithms supported by the\nversion of OpenSSL on the platform. Examples are 'sha256'
, 'sha512'
, etc.\nOn recent releases of OpenSSL, openssl list-message-digest-algorithms
will\ndisplay the available digest algorithms.
Example: generating the sha256 sum of a file
\nconst filename = process.argv[2];\nconst crypto = require('crypto');\nconst fs = require('fs');\n\nconst hash = crypto.createHash('sha256');\n\nconst input = fs.createReadStream(filename);\ninput.on('readable', () => {\n var data = input.read();\n if (data)\n hash.update(data);\n else {\n console.log(`${hash.digest('hex')} ${filename}`);\n }\n});\n
\n",
"signatures": [
{
"params": [
{
"name": "algorithm"
}
]
}
]
},
{
"textRaw": "crypto.createHmac(algorithm, key)",
"type": "method",
"name": "createHmac",
"meta": {
"added": [
"v0.1.94"
]
},
"desc": "Creates and returns an Hmac
object that uses the given algorithm
and key
.
The algorithm
is dependent on the available algorithms supported by the\nversion of OpenSSL on the platform. Examples are 'sha256'
, 'sha512'
, etc.\nOn recent releases of OpenSSL, openssl list-message-digest-algorithms
will\ndisplay the available digest algorithms.
The key
is the HMAC key used to generate the cryptographic HMAC hash.
Example: generating the sha256 HMAC of a file
\nconst filename = process.argv[2];\nconst crypto = require('crypto');\nconst fs = require('fs');\n\nconst hmac = crypto.createHmac('sha256', 'a secret');\n\nconst input = fs.createReadStream(filename);\ninput.on('readable', () => {\n var data = input.read();\n if (data)\n hmac.update(data);\n else {\n console.log(`${hmac.digest('hex')} ${filename}`);\n }\n});\n
\n",
"signatures": [
{
"params": [
{
"name": "algorithm"
},
{
"name": "key"
}
]
}
]
},
{
"textRaw": "crypto.createSign(algorithm)",
"type": "method",
"name": "createSign",
"meta": {
"added": [
"v0.1.92"
]
},
"desc": "Creates and returns a Sign
object that uses the given algorithm
.\nUse crypto.getHashes()
to obtain an array of names of the available\nsigning algorithms.
Creates and returns a Verify
object that uses the given algorithm.\nUse crypto.getHashes()
to obtain an array of names of the available\nsigning algorithms.
Returns an array with the names of the supported cipher algorithms.
\nExample:
\nconst ciphers = crypto.getCiphers();\nconsole.log(ciphers); // ['aes-128-cbc', 'aes-128-ccm', ...]\n
\n",
"signatures": [
{
"params": []
}
]
},
{
"textRaw": "crypto.getCurves()",
"type": "method",
"name": "getCurves",
"meta": {
"added": [
"v2.3.0"
]
},
"desc": "Returns an array with the names of the supported elliptic curves.
\nExample:
\nconst curves = crypto.getCurves();\nconsole.log(curves); // ['secp256k1', 'secp384r1', ...]\n
\n",
"signatures": [
{
"params": []
}
]
},
{
"textRaw": "crypto.getDiffieHellman(group_name)",
"type": "method",
"name": "getDiffieHellman",
"meta": {
"added": [
"v0.7.5"
]
},
"desc": "Creates a predefined DiffieHellman
key exchange object. The\nsupported groups are: 'modp1'
, 'modp2'
, 'modp5'
(defined in\nRFC 2412, but see Caveats) and 'modp14'
, 'modp15'
,\n'modp16'
, 'modp17'
, 'modp18'
(defined in RFC 3526). The\nreturned object mimics the interface of objects created by\ncrypto.createDiffieHellman()
, but will not allow changing\nthe keys (with diffieHellman.setPublicKey()
for example). The\nadvantage of using this method is that the parties do not have to\ngenerate nor exchange a group modulus beforehand, saving both processor\nand communication time.
Example (obtaining a shared secret):
\nconst crypto = require('crypto');\nconst alice = crypto.getDiffieHellman('modp14');\nconst bob = crypto.getDiffieHellman('modp14');\n\nalice.generateKeys();\nbob.generateKeys();\n\nconst alice_secret = alice.computeSecret(bob.getPublicKey(), null, 'hex');\nconst bob_secret = bob.computeSecret(alice.getPublicKey(), null, 'hex');\n\n/* alice_secret and bob_secret should be the same */\nconsole.log(alice_secret == bob_secret);\n
\n",
"signatures": [
{
"params": [
{
"name": "group_name"
}
]
}
]
},
{
"textRaw": "crypto.getHashes()",
"type": "method",
"name": "getHashes",
"meta": {
"added": [
"v0.9.3"
]
},
"desc": "Returns an array of the names of the supported hash algorithms,\nsuch as RSA-SHA256
.
Example:
\nconst hashes = crypto.getHashes();\nconsole.log(hashes); // ['sha', 'sha1', 'sha1WithRSAEncryption', ...]\n
\n",
"signatures": [
{
"params": []
}
]
},
{
"textRaw": "crypto.pbkdf2(password, salt, iterations, keylen[, digest], callback)",
"type": "method",
"name": "pbkdf2",
"meta": {
"added": [
"v0.5.5"
]
},
"desc": "Provides an asynchronous Password-Based Key Derivation Function 2 (PBKDF2)\nimplementation. A selected HMAC digest algorithm specified by digest
is\napplied to derive a key of the requested byte length (keylen
) from the\npassword
, salt
and iterations
. If the digest
algorithm is not specified,\na default of 'sha1'
is used.
The supplied callback
function is called with two arguments: err
and\nderivedKey
. If an error occurs, err
will be set; otherwise err
will be\nnull. The successfully generated derivedKey
will be passed as a Buffer
.
The iterations
argument must be a number set as high as possible. The\nhigher the number of iterations, the more secure the derived key will be,\nbut will take a longer amount of time to complete.
The salt
should also be as unique as possible. It is recommended that the\nsalts are random and their lengths are greater than 16 bytes. See\nNIST SP 800-132 for details.
Example:
\nconst crypto = require('crypto');\ncrypto.pbkdf2('secret', 'salt', 100000, 512, 'sha512', (err, key) => {\n if (err) throw err;\n console.log(key.toString('hex')); // 'c5e478d...1469e50'\n});\n
\nAn array of supported digest functions can be retrieved using\ncrypto.getHashes()
.
Provides a synchronous Password-Based Key Derivation Function 2 (PBKDF2)\nimplementation. A selected HMAC digest algorithm specified by digest
is\napplied to derive a key of the requested byte length (keylen
) from the\npassword
, salt
and iterations
. If the digest
algorithm is not specified,\na default of 'sha1'
is used.
If an error occurs an Error will be thrown, otherwise the derived key will be\nreturned as a Buffer
.
The iterations
argument must be a number set as high as possible. The\nhigher the number of iterations, the more secure the derived key will be,\nbut will take a longer amount of time to complete.
The salt
should also be as unique as possible. It is recommended that the\nsalts are random and their lengths are greater than 16 bytes. See\nNIST SP 800-132 for details.
Example:
\nconst crypto = require('crypto');\nconst key = crypto.pbkdf2Sync('secret', 'salt', 100000, 512, 'sha512');\nconsole.log(key.toString('hex')); // 'c5e478d...1469e50'\n
\nAn array of supported digest functions can be retrieved using\ncrypto.getHashes()
.
Decrypts buffer
with private_key
.
private_key
can be an object or a string. If private_key
is a string, it is\ntreated as the key with no passphrase and will use RSA_PKCS1_OAEP_PADDING
.\nIf private_key
is an object, it is interpreted as a hash object with the\nkeys:
key
: {String} - PEM encoded private keypassphrase
: {String} - Optional passphrase for the private keypadding
: An optional padding value, one of the following:constants.RSA_NO_PADDING
constants.RSA_PKCS1_PADDING
constants.RSA_PKCS1_OAEP_PADDING
All paddings are defined in the constants
module.
Encrypts buffer
with private_key
.
private_key
can be an object or a string. If private_key
is a string, it is\ntreated as the key with no passphrase and will use RSA_PKCS1_PADDING
.\nIf private_key
is an object, it is interpreted as a hash object with the\nkeys:
key
: {String} - PEM encoded private keypassphrase
: {String} - Optional passphrase for the private keypadding
: An optional padding value, one of the following:constants.RSA_NO_PADDING
constants.RSA_PKCS1_PADDING
All paddings are defined in the constants
module.
Decrypts buffer
with public_key
.
public_key
can be an object or a string. If public_key
is a string, it is\ntreated as the key with no passphrase and will use RSA_PKCS1_PADDING
.\nIf public_key
is an object, it is interpreted as a hash object with the\nkeys:
key
: {String} - PEM encoded public keypassphrase
: {String} - Optional passphrase for the private keypadding
: An optional padding value, one of the following:constants.RSA_NO_PADDING
constants.RSA_PKCS1_PADDING
constants.RSA_PKCS1_OAEP_PADDING
Because RSA public keys can be derived from private keys, a private key may\nbe passed instead of a public key.
\nAll paddings are defined in the constants
module.
Encrypts buffer
with public_key
.
public_key
can be an object or a string. If public_key
is a string, it is\ntreated as the key with no passphrase and will use RSA_PKCS1_OAEP_PADDING
.\nIf public_key
is an object, it is interpreted as a hash object with the\nkeys:
key
: {String} - PEM encoded public keypassphrase
: {String} - Optional passphrase for the private keypadding
: An optional padding value, one of the following:constants.RSA_NO_PADDING
constants.RSA_PKCS1_PADDING
constants.RSA_PKCS1_OAEP_PADDING
Because RSA public keys can be derived from private keys, a private key may\nbe passed instead of a public key.
\nAll paddings are defined in the constants
module.
Generates cryptographically strong pseudo-random data. The size
argument\nis a number indicating the number of bytes to generate.
If a callback
function is provided, the bytes are generated asynchronously\nand the callback
function is invoked with two arguments: err
and buf
.\nIf an error occurs, err
will be an Error object; otherwise it is null. The\nbuf
argument is a Buffer
containing the generated bytes.
// Asynchronous\nconst crypto = require('crypto');\ncrypto.randomBytes(256, (err, buf) => {\n if (err) throw err;\n console.log(`${buf.length} bytes of random data: ${buf.toString('hex')}`);\n});\n
\nIf the callback
function is not provided, the random bytes are generated\nsynchronously and returned as a Buffer
. An error will be thrown if\nthere is a problem generating the bytes.
// Synchronous\nconst buf = crypto.randomBytes(256);\nconsole.log(\n `${buf.length} bytes of random data: ${buf.toString('hex')}`);\n
\nThe crypto.randomBytes()
method will block until there is sufficient entropy.\nThis should normally never take longer than a few milliseconds. The only time\nwhen generating the random bytes may conceivably block for a longer period of\ntime is right after boot, when the whole system is still low on entropy.
Load and set the engine
for some or all OpenSSL functions (selected by flags).
engine
could be either an id or a path to the engine's shared library.
The optional flags
argument uses ENGINE_METHOD_ALL
by default. The flags
\nis a bit field taking one of or a mix of the following flags (defined in the\nconstants
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
The Crypto module was added to Node.js before there was the concept of a\nunified Stream API, and before there were Buffer
objects for handling\nbinary data. As such, the many of the crypto
defined classes have methods not\ntypically found on other Node.js classes that implement the streams\nAPI (e.g. update()
, final()
, or digest()
). Also, many methods accepted\nand returned 'binary'
encoded strings by default rather than Buffers. This\ndefault was changed after Node.js v0.8 to use Buffer
objects by default\ninstead.
Usage of ECDH
with non-dynamically generated key pairs has been simplified.\nNow, ecdh.setPrivateKey()
can be called with a preselected private key\nand the associated public point (key) will be computed and stored in the object.\nThis allows code to only store and provide the private part of the EC key pair.\necdh.setPrivateKey()
now also validates that the private key is valid for\nthe selected curve.
The ecdh.setPublicKey()
method is now deprecated as its inclusion in the\nAPI is not useful. Either a previously stored private key should be set, which\nautomatically generates the associated public key, or ecdh.generateKeys()
\nshould be called. The main drawback of using ecdh.setPublicKey()
is that\nit can be used to put the ECDH key pair into an inconsistent state.
The crypto
module still supports some algorithms which are already\ncompromised and are not currently recommended for use. The API also allows\nthe use of ciphers and hashes with a small key size that are considered to be\ntoo weak for safe use.
Users should take full responsibility for selecting the crypto\nalgorithm and key size according to their security requirements.
\nBased on the recommendations of NIST SP 800-131A:
\nmodp1
, modp2
and modp5
have a key size\nsmaller than 2048 bits and are not recommended.See the reference for other recommendations and details.
\n", "type": "module", "displayName": "Support for weak or compromised algorithms" } ], "type": "module", "displayName": "Notes" } ], "type": "module", "displayName": "Crypto" } ] }