Javascript library for signing and encrypting data.
- Consistent API across Node.js and browser.
- On Node.js wraps crypto and ursa modules.
- On browser wraps SlowAES, pbkdf2.js, CryptoJS, jsrsasign and js-rsa-pem.
- Hard-coded to HMAC-SHA-256 for symmetric signing.
- Hard-coded to RSA-SHA-256 with RSASSA-PSS encoding for asymmetric signing.
- Hard-coded to AES-128-CBC for symmetric key encryption (with optional SHA-256 checksum).
- Hard-coded to RSA, RSAES-OAEP encoding and AES-128-CBC for asymmetric encryption (with optional SHA-256 checksum).
- Verification and decryption operations included.
- Support for deriving signing and encryption key from a password using PBKDF2-SHA1.
- JSON encoding of data by default.
- Unit tests, including NIST test vectors and tests for interoperability between Node.js and browser (using PhantomJS).
Example:
var Crypt = require('simple-crypt').Crypt;
var data = { device_id: 'temperature_sensor0', value: 15.765 };
Crypt.make('my signing key', function (err, signer)
{
signer.sign(data, function (err, signed)
{
Crypt.make(this.get_key(), function (err, verifier)
{
verifier.verify(signed, function (err, verified)
{
assert.deepEqual(verified, data);
});
});
});
});
The API is described here.
Please feel free to make any comments (or pull requests), especially if you notice something wrong!
Node.js:
npm install simple-crypt
Browser:
<script type="text/javascript" src="dist/simple-crypt-deps.js"></script>
<script type="text/javascript" src="dist/simple-crypt.js"></script>
Crypt.make(crypto.randomBytes(Crypt.get_key_size()), function (err, encrypter)
{
encrypter.encrypt(data, function (err, encrypted)
{
Crypt.make(this.get_key(), function (err, decrypter)
{
decrypter.decrypt(encrypted, function (err, decrypted)
{
assert.deepEqual(decrypted, data);
});
});
});
});
var priv_pem = "-----BEGIN RSA PRIVATE KEY-----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\nvjFmyDdU5Hh6ma4q+BeAqbXZSJz0cfkBcBLCSe2gIJ/QJ3YJVQI=\n-----END RSA PRIVATE KEY-----";
var pub_pem = "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA4qiw8PWs7PpnnC2BUEoD\nRcwXF8pq8XT1/3Hc3cuUJwX/otNefr/Bomr3dtM0ERLN3DrepCXvuzEU5FcJVDUB\n3sI+pFtjjLBXD/zJmuL3Afg91J9p79+Dm+43cR6wuKywVJx5DJIdswF6oQDDzhwu\n89d2V5x02aXB9LqdXkPwiO0eR5s/xHXgASl+hqDdVL9hLod3iGa9nV7cElCbcl8U\nVXNPJnQAfaiKazF+hCdl/syrIh0KCZ5opggsTJibo8qFXBmG4PkT5YbhHE11wYKI\nLwZFSvZ9iddRPQK3CtgFiBnXbVwU5t67tn9pMizHgypgsfBoeoyBrpTuc4egSCpj\nsQIDAQAB\n-----END PUBLIC KEY-----";
Crypt.make(priv_pem, function (err, signer)
{
signer.sign(data, function (err, signed)
{
Crypt.make(pub_pem, function (err, verifier)
{
verifier.verify(signed, function (err, verified)
{
assert.deepEqual(verified, data);
});
});
});
});
Crypt.make(pub_pem, function (err, encrypter)
{
encrypter.encrypt(data, function (err, encrypted)
{
Crypt.make(priv_pem, function (err, decrypter)
{
decrypter.decrypt(encrypted, function (err, decrypted)
{
assert.deepEqual(decrypted, data);
});
});
});
});
var pw_info = { password: 'P@ssW0rd!', iterations: 10000 };
Crypt.make(pw_info, function (err, signer)
{
signer.sign(data, function (err, signed)
{
var salted = Object.create(pw_info);
salted.salt = this.get_key().salt;
Crypt.make(salted, function (err, verifier)
{
verifier.verify(signed, function (err, verified)
{
assert.deepEqual(verified, data);
});
});
});
});
Crypt.make(pw_info, function (err, encrypter)
{
encrypter.encrypt(data, function (err, encrypted)
{
var salted = Object.create(pw_info);
salted.salt = this.get_key().salt;
Crypt.make(salted, function (err, decrypter)
{
decrypter.decrypt(encrypted, function (err, decrypted)
{
assert.deepEqual(decrypted, data);
});
});
});
});
Crypt.make('some key', function (err, signer)
{
signer.maybe_sign(false, data, function (err, signed)
{
assert.equal(signed.signed, false);
Crypt.make(this.get_key(), function (err, verifier)
{
verifier.maybe_verify(signed, function (err, verified)
{
assert.deepEqual(verified, data);
});
});
});
});
Crypt.make(crypto.randomBytes(Crypt.get_key_size()), function (err, encrypter)
{
encrypter.maybe_encrypt(true, data, function (err, encrypted)
{
assert.equal(encrypted.encrypted, true);
Crypt.make(this.get_key(), function (err, decrypter)
{
decrypter.maybe_decrypt(encrypted, function (err, decrypted)
{
assert.deepEqual(decrypted, data);
});
});
});
});
var pub_pems = { temperature_sensor0: pub_pem };
var priv_pems = { temperature_sensor0: priv_pem };
Crypt.make().maybe_sign(data, function (err, signed)
{
assert.equal(signed.signed, true);
Crypt.make().maybe_verify(signed, function (err, verified)
{
assert.deepEqual(verified, data);
}, function (cb, device_id)
{
cb(null, pub_pems[device_id]);
});
}, function (device_id, cb)
{
cb(null, priv_pems[device_id], device_id);
}, data.device_id);
Crypt.make().maybe_encrypt(data, function (err, encrypted)
{
assert.equal(encrypted.encrypted, true);
Crypt.make().maybe_decrypt(encrypted, function (err, decrypted)
{
assert.deepEqual(decrypted, data);
}, function (cb, device_id)
{
cb(null, priv_pems[device_id]);
});
}, function (device_id, cb)
{
cb(null, pub_pems[device_id], device_id);
}, data.device_id);
Crypt.sign_encrypt_sign(priv_pem, pub_pem, data, function (err, data_out)
{
Crypt.verify_decrypt_verify(priv_pem, pub_pem, data_out, function (err, data_in)
{
assert.deepEqual(data_in, data);
});
});
Crypt.make('some signing key', { json: false }, function (err, signer)
{
signer.sign(new Buffer('"hello"'), function (err, signed)
{
this.verify(signed, function (err, verified)
{
assert.equal(verified, '"hello"');
});
});
});
grunt test
grunt lint
grunt coverage
Instanbul results are available here.
Coveralls page is here.
grunt bench
Here are some results on a laptop with an Intel Core i5-3210M 2.5Ghz CPU and 6Gb RAM running Ubuntu 13.10.
In the tables, fast is the normal simple-crypt Node.js code wrapper and slow is the browser code running on Node.js (not in a browser).
derive_key_from_password x10 | total (ms) | average (ns) | diff (%) |
---|---|---|---|
fast | 68 | 6,798,449 | - |
slow | 21,970 | 2,197,037,726 | 32,217 |
encrypt_decrypt_asymmetric x1,000 | total (ms) | average (ns) | diff (%) |
---|---|---|---|
fast | 2,899 | 2,899,138 | - |
slow | 131,420 | 131,419,631 | 4,433 |
encrypt_decrypt_symmetric x1,000 | total (ms) | average (ns) | diff (%) |
---|---|---|---|
fast | 422 | 421,697 | - |
slow | 59,989 | 59,989,311 | 14,126 |
load_rsa_privkey x1,000 | total (ms) | average (ns) | diff (%) |
---|---|---|---|
fast | 44 | 44,325 | - |
slow | 225 | 224,776 | 407 |
sign_verify_asymmetric x1,000 | total (ms) | average (ns) | diff (%) |
---|---|---|---|
fast | 2,843 | 2,843,213 | - |
slow | 520,668 | 520,668,069 | 18,213 |
sign_verify_symmetric x1,000 | total (ms) | average (ns) | diff (%) |
---|---|---|---|
fast | 347 | 347,185 | - |
slow | 3,130 | 3,129,778 | 801 |
- Crypt.prototype.maybe_encrypt
- Crypt.prototype.maybe_decrypt
- Crypt.prototype.maybe_sign
- Crypt.prototype.maybe_verify
Create a new
Crypt
object which can be used to sign, verify, encrypt and decrypt data.
Parameters:
-
{String | Buffer | Object} [key]
Optional key to use for operations using this object.-
If you pass a string which looks like it's PEM-encoded then it will be loaded as a RSA key.
-
If you pass an object then its
password
,iterations
and optionalsalt
properties will be used to derive a key using PBKDF2-SHA1. If you don't supply a salt then a random one is created. You can also supply an optionalprogress
property, which must be a function and is called with the percentage completion as the key is derived. -
Otherwise the key should be a
Buffer
or binary-encoded string, length equal to get_key_size. It will be used as a symmetric key for encryption or signing. -
Omit the key (or pass
undefined
) if you intend to use one of the dynamic key retrieval methods. -
Note that how you exchange public keys, passwords or symmetric keys with other parties is beyond the scope of this library. You might consider using something like Diffie-Hellman to exchange symmetric keys but you might also need some kind of public key infrastructure to authenticate the message. That's just an example.
-
Note also that if you intend to use the same key for multiple purposes, consider using a key derivation function to derive separate keys and call Crypt.make separately for each. For examples of key derivation functions, see the following:
-
-
{Object} [options]
Optional settings:-
{Boolean} json
Whether to JSON encode and decode data. Default istrue
. -
{Boolean} check
Whether to add a checksum to encrypted data and verify it when decrypting data. Default istrue
. -
{Boolean} pad
Whether to automatically pad encrypted data (using PKCS#7) to a multiple of the AES block size (16 bytes). Default istrue
.
-
-
{Function} [cb]
Optional function called with theCrypt
object. It's passed the following arguments:
Return:
{Crypt}
The Crypt
object. It will have no key until key parsing is complete and cb
is called.
Get the size (in bytes) of symmetric encryption keys. Use this value when creating keys for use with Crypt.prototype.encrypt and Crypt.prototype.decrypt.
Return:
{Number}
Encryption key size.
Parse a key. Call this if you want to use the same key for multiple
Crypt
objects but only incur the cost of parsing it once.
Parameters:
{String | Buffer | Object} key
Key to parse. See thekey
parameter of Crypt.make.{Function} cb
Function called with the parsed key. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{String|Buffer|Object} key
Parsed key. You can pass this to Crypt.make. If the key looks like a PEM-encoded RSA key then an internal RSA key object is received. If the key is an object (withpassword
,iterations
and optionalsalt
properties) then an object with the following properties is received:-
{Object} key
An AES encryption key derived using PBKDF2-SHA-1. -
{Buffer|String} salt
Binary-encoded salt value which was used to derivekey
.
-
-
Get the key being used by this
Crypt
object.
Return:
{Object | Buffer | String}
The key. This could be a Buffer
, binary-encoded string, internal RSA key object or an object containing a key derived from a password (see parse_key).
Go: TOC | Crypt.prototype
Encrypt data using AES-128-CBC and the key you passed to Crypt.make when you created this object. If you passed a (PEM-encoded) RSA public key then a random AES key is created and the public key is used to encrypt it (using RSAES-OAEP). The encrypted AES key is made available along with the encrypted data (see below).
Parameters:
-
{Object | Buffer | String} data
The data to be encrypted.-
If you didn't pass
options.json
asfalse
to Crypt.make then the data will be JSON-serialized before it's encrypted. Otherwise, it must be aBuffer
or binary-encoded string. -
If you didn't pass
options.check
asfalse
to Crypt.make then a SHA-256 checksum is prepended to the data before it's encrypted. -
If you didn't pass
options.pad
asfalse
to Crypt.make then the data will be padded to a multiple of 16 bytes.
-
-
{Buffer | String} [iv]
Optional initialisation vector (salt) to use for AES encryption. If not supplied, a random one is created. -
{Function} cb
Function called with the result. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object} result
Result of the encryption. Typically you would JSON serialize this for transmission. It has the following properties:-
{String} iv
Base64-encoded initialisation vector used for the encryption. -
{String} data
Base64-encoded encrypted data. -
{String} ekey
Base64-encoded encrypted AES key (only present when using RSA public key -- see above). -
{Number} version
Internal version number for future compatibility checking.
-
-
Go: TOC | Crypt.prototype
Decrypt data using AES-128-CBC and the key you passed to Crypt.make when you created this object. If you passed a (PEM-encoded) RSA private key then an
ekey
property is expected to be present on thedata
parameter (below). The private key is used to decrypt theekey
in order to obtain the AES key.
Parameters:
-
{Object} data
A result object received from encrypt. You may have received this from another party, for instance.-
If you didn't pass
options.json
asfalse
to Crypt.make then the data will be JSON-parsed after it's encrypted. Otherwise, you'll receive aBuffer
(on Node.js) or binary-encoded string. -
If you didn't pass
options.check
asfalse
to Crypt.make then a SHA-256 checksum is expected to be prepended to the decrypted data. The checksum is verified against the rest of the decrypted data. -
If you didn't pass
options.pad
asfalse
to Crypt.make then the decrypted data is expected to be padded to a multiple of 16 bytes and will be unpadded automatically.
-
-
{Function} cb
Function called with the result. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object|Buffer|String} data
The decrypted data.
-
Go: TOC | Crypt.prototype
Sign a SHA-256 hash of some data using the key you passed to Crypt.make when you created this object. If you passed a (PEM-encoded) RSA private key then the hash is signed using RSASSA-PSS. Otherwise, HMAC-SHA-256 is used to sign the data.
Parameters:
-
{Object | Buffer | String} data
The data to be signed.- If you didn't pass
options.json
asfalse
to Crypt.make then the data will be JSON-serialized before it's encrypted. Otherwise, it must be aBuffer
or binary-encoded string.
- If you didn't pass
-
{Function} cb
Function called with the result. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object} result
Result of signing the data. Typically you would JSON serialize this for transmission. It has the following properties:-
{String} data
The data that was signed (Base64-encoded). -
{String} signature
Base64-encoded signed hash of the data. -
{Number} version
Internal version number for future compatibility checking.
-
-
Go: TOC | Crypt.prototype
Verify a signature by comparing it to a signed SHA-256 hash of some data. The signed hash is generated using the key you passed to Crypt.make when you created this object. If you passed a (PEM-encoded) RSA public key then the hash is signed using RSASSA-PSS. Otherwise HMAC is used.
Parameters:
-
{Object} data
A result object received from sign. You may have received this from another party, for instance.- If you didn't pass
options.json
asfalse
to Crypt.make then the data will be JSON-parsed after it's verified. Otherwise, you'll receive aBuffer
(on Node.js) or binary-encoded string.
- If you didn't pass
-
{Function} cb
Function called with the result. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object|Buffer|String} data
The verified data.
-
Go: TOC | Crypt.prototype
Sign then encrypt then sign data. Convenience function which creates two
Crypt
objects, calls sign on the first, plumbs the result into encrypt on the second and then plumbs the result from that into sign on the first again. See this article for a discussion of why just sign then encrypt isn't good enough.
Parameters:
{String} signing_key
Key to use for signing the data.{String} encryption_key
Key to use for encrypting the data and signature.{Object | Buffer | String} data
The data to be signed and encrypted.{Buffer | String} [iv]
Optional initialisation vector (salt) to use for encryption. If not supplied, a random one is created.{Function} cb
Function called with the result. It's passed the following arguments:{Object} err
If an error occurred then details of the error, otherwisenull
.{Object} result
Result of signing and encrypting the data. See the description ofcb
for sign.
Verify then decrypt then verify data. Convenience function which creates two
Crypt
objects, calls verify on the first, plumbs the result into decrypt on the second and then plumbs the result from that into verify on the first again.
Parameters:
{String} decryption_key
Key to use for decrypting the data and signature.{String} verifying_key
Key to use for verifying the signature.{Object} data
A result object received from sign_encrypt_sign.{Function} cb
Function called with the result. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object|Buffer|String} data
The decrypted and verified data.
-
Conditionally encrypt data using encrypt.
Parameters:
-
{Boolean} encrypt
Whether to encrypt the data. -
{Object | Buffer | String} data
The data to encrypt. -
{Function} cb
Function called with the result. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object} result
Result object with the following properties:-
{Boolean} encrypted
Whether the data was encrypted. -
{Object} data
Encryption result (data, initialisation vector etc) if the data was encrypted, otherwise the data. -
{Object} [key_data]
If the data was encrypted andget_key
was called (see below) then this is the key data received fromget_key
.
-
-
-
{Function} [get_key]
Optional function to call in order to get the encryption key. You must supply this if you didn't supply a key when creating theCrypt
object.get_key
is called with the following arguments:-
The arguments to
maybe_encrypt
that followget_key
(if any). -
{Function} got_key
Function to call with the key. You should call it with the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object|Buffer|String} key
The encryption key. If this is a falsey value then the data won't be encrypted. -
{Object} [key_data]
Optional metadata for the key. This is included in the result (see above). -
{Buffer|String} [iv]
Optional initialisation vector.
-
-
Go: TOC | Crypt.prototype
Conditionally decrypt data using decrypt.
Parameters:
-
{Object} data
A result object received from maybe_encrypt. -
{Function} cb
Function called with the result. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object|Buffer|String} data
If the data was encrypted then the decrypted data otherwise the data.
-
-
{Function} [get_key]
Optional function to call in order to get the encryption key. You must supply this if you didn't supply a key when creating theCrypt
object.get_key
is called with the following arguments:-
The arguments to
maybe_decrypt
that followget_key
(if any). -
{Function} got_key
Function to call with the key. You should call it with the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object|Buffer|String} key
The decryption key.
-
-
{Object} [key_data]
Metadata for the key which was supplied in maybe_encrypt (if any).
-
Go: TOC | Crypt.prototype
Conditionally sign data using sign.
Parameters:
-
{Boolean} sign
Whether to sign the data. -
{Object | Buffer | String} data
The data to sign. -
{Function} cb
Function called with the result. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object} result
Result object with the following properties:-
{Boolean} signed
Whether the data was signed. -
{Object} data
Signing result (data, signature etc) if the data was signed, otherwise the data. -
{Object} [key_data]
If the data was signed andget_key
was called (see below) then this is the key data received fromget_key
.
-
-
-
{Function} [get_key]
Optional function to call in order to get the signing key. You must supply this if you didn't supply a key when creating theCrypt
object.get_key
is called with the following arguments:-
The arguments to
maybe_sign
that followget_key
(if any). -
{Function} got_key
Function to call with the key. You should call it with the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object|Buffer|String} key
The signing key. If this is a falsey value then the data won't be signed. -
{Object} [key_data]
Optional metadata for the key. This is included in the result (see above).
-
-
Go: TOC | Crypt.prototype
Conditionally verify data using verify.
Parameters:
-
{Object} data
A result object received from maybe_sign. -
{Function} cb
Function called with the result. It's passed the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object|Buffer|String} data
If the data was signed then the verified data otherwise the data.
-
-
{Function} [get_key]
Optional function to call in order to get the verifying key. You must supply this if you didn't supply a key when creating theCrypt
object.get_key
is called with the following arguments:-
The arguments to
maybe_verify
that followget_key
(if any). -
{Function} got_key
Function to call with the key. You should call it with the following arguments:-
{Object} err
If an error occurred then details of the error, otherwisenull
. -
{Object|Buffer|String} key
The verifying key.
-
-
{Object} [key_data]
Metadata for the key which was supplied in maybe_sign (if any).
-
Go: TOC | Crypt.prototype
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