The rampart-crypto module¶

Preface¶

Acknowledgment¶

The rampart-crypto module uses the OpenSSL library. We extend our thanks to the developers for this indispensable tool.

License¶

The rampart-crypto module is released under the MIT license. The OpenSSL library is released under the OpenSSL License.

What does it do?¶

The rampart-crypto module provides methods to encrypt, decrypt, hash and generate HMACs from within Rampart JavaScript. It also includes the full libssl and libcrypto libraries and is needed for the rampart-curl and rampart-server modules to operate using the https protocol.

How does it work?¶

After the module is loaded, functions are provided to perform crypto operations on JavaScript Strings or Buffers.

Loading and Using the Module¶

Loading¶

Loading the module is a simple matter of using the require() function:

                          var crypto = require("rampart-crypto");

                        

Encryption and Decryption¶

encrypt¶

The encrypt() function encrypts the contents of a String or Buffer. Encryption can be done by providing a key/iv pair or by providing a password.

Usage:

                          var crypto = require("rampart-crypto");

var ciphertext = crypto.encrypt(options);

/* or */

var ciphertext = crypto.encrypt(pass, data[, cipher_mode]);

Where:

pass is a password used to encrypt the data.
data is a String or Buffer, the data to be encrypted.
cipher_mode is one of the Supported Modes listed below. If not specified, the default is aes-256-cbc.
options is an Object which may contain the following:
- data - same as data above.
- cipher - same as cipher_mode above.
- pass - a password used to generate a key/iv pair and encrypt the data.
- key - required if not using a password - a key of the appropriate length for the chosen cipher. key can be a Buffer or a hex encoded String.
- iv - required if not using a password - an initialization vector of the appropriate length to be used for encrypting the data. iv can be a Buffer or a hex encoded String.
- iter - number of iterations for generating a key and iv from pass. Default is 10000. If provided, the same value must be passed to decrypt below in order to decrypt the ciphertext.

Return Value:: A Buffer containing the ciphertext (encrypted data). Using crypto.encrypt("password", data) produces the same results as openssl enc -aes-256-cbc -e -pbkdf2 -pass pass:"password" -in myfile.txt using openssl version 1.1.1 from the command line.

Example:

                          var crypto = require("rampart-crypto");

var ciphertext = crypto.encrypt("mypass", "my data", "aes-128-cbc");

Caveat:: The choice of 10000 iterations is the default used by both the command line openssl tool and rampart-crypto. It is purposefully slow, in order to make dictionary attacks on the password difficult. If computational speed is a factor (e.g. in a HTTP server context), choosing a password of random characters and significantly lowering the iter value (or using the key and iv options instead of a password) will be more performant.

decrypt¶

The decrypt() function takes the same arguments as encrypt above, but decrypts the data.

Return Value:: A Buffer containing the decrypted text. Calling crypto.decrypt("password", data) produces the same results as openssl enc -aes-256-cbc -d -pbkdf2 -pass pass:"password" -in myfile.enc using openssl version 1.1.1 from the command line.

Example:

                          var crypto = require("rampart-crypto");

var ciphertext = crypto.encrypt({
    pass: "mypass",
    data: "my data"
});

var plaintext = crypto.decrypt({
    pass: "mypass",
    data: ciphertext
});

rampart.utils.printf('The decrypted data: "%s"\n', plaintext);

/* expected output:

The decrypted data: "my data"

*/

                        

passToKeyIv¶

The passToKeyIv() function performs the same password to key/iv pair generation as encrypt above.

Usage:

                          var crypto = require("rampart-crypto");

var kiv = crypto.passToKeyIv(options);

Where

options is an Object which may contain the following:
- cipher is a String and is one of the Supported Modes listed below. If not specified, the default is aes-256-cbc. This option controls the key and iv length.
- pass is a String, the password used to generate a key/iv pair.
- salt is a String or Buffer, the optional salt for generation of the key and iv. If not provided, a random salt will be generated. If provided as a String it must be a hex encoded string representing at least 8 bytes. If provided as a Buffer, it must be at least 8 bytes in length. If longer than 8 bytes, only the first 8 bytes will be used.
- iter - number of iterations for generating a key and iv from pass. Default is 10000.
- returnBuffer is an Boolean, if true the key, iv and salt will be returned as binary data in Buffers. Otherwise if not set or false, they will be encoded as a hex Strings.

Return Value:: An Object containing the key, iv and salt as hex encoded Strings or as binary data in Buffers. The function crypto.passToKeyIv produces the same results as openssl enc -<cipher_mode> -pbkdf2 -k <password> [-S <salt_as_hex>] -P using openssl version 1.1.1 from the command line.

Example:

                          var crypto = require("rampart-crypto");

var salt = crypto.sha1("a unique string for one time use as salt");

var kiv = crypto.passToKeyIv({
   pass: "mypass",
   salt: salt
});

var ciphertext = crypto.encrypt({
    key:  kiv.key,
    iv:   kiv.iv,
    data: "my data"
});

/*
   note that when key/iv is used in encrypt instead of a password, salt
   is not stored in the ciphertext, and the ciphertext must be decrypted
   with the same key, iv derived using both 'password' and 'salt'.
*/

var plaintext = crypto.decrypt({
    key:  kiv.key,
    iv:   kiv.iv,
    data: ciphertext
});

rampart.utils.printf('Key/Iv/Salt: "%3J"\n\n', kiv);

rampart.utils.printf('The decrypted data: "%s"\n', plaintext);

/* expected output:

Key/Iv/Salt: "{
   "key": "215a744a875c4604046f05a34164507cf9f8c54342f75b1d58ad5d1f428aadd2",
   "iv": "daffcd9ff10128eee4f19375f1aa4dde",
   "salt": "ce37ddf6cda911f4"
}"

The decrypted data: "my data"

*/

                        

Supported Modes¶

The following cipher/modes are supported in rampart:

mode name	Description
bf-cbc	Blowfish in CBC mode
bf-cfb	Blowfish in CFB mode
bf-ecb	Blowfish in ECB mode
bf-ofb	Blowfish in OFB mode
cast-cbc	CAST in CBC mode
cast5-cbc	CAST5 in CBC mode
cast5-cfb	CAST5 in CFB mode
cast5-ecb	CAST5 in ECB mode
cast5-ofb	CAST5 in OFB mode
des-cbc	DES in CBC mode
des-cfb	DES in CBC mode
des-ofb	DES in OFB mode
des-ecb	DES in ECB mode
des-ede-cbc	Two key triple DES EDE in CBC mode
des-ede	Two key triple DES EDE in ECB mode
des-ede-cfb	Two key triple DES EDE in CFB mode
des-ede-ofb	Two key triple DES EDE in OFB mode
des-ede3-cbc	Three key triple DES EDE in CBC mode
des-ede3	Three key triple DES EDE in ECB mode
des-ede3-cfb	Three key triple DES EDE CFB mode
des-ede3-ofb	Three key triple DES EDE in OFB mode
desx	DESX algorithm.
idea-cbc	IDEA algorithm in CBC mode
idea-cfb	IDEA in CFB mode
idea-ecb	IDEA in ECB mode
idea-ofb	IDEA in OFB mode
rc2-cbc	128 bit RC2 in CBC mode
rc2-cfb	128 bit RC2 in CFB mode
rc2-ecb	128 bit RC2 in ECB mode
rc2-ofb	128 bit RC2 in OFB mode
rc2-64-cbc	64 bit RC2 in CBC mode
rc2-40-cbc	40 bit RC2 in CBC mode
rc4	128 bit RC4
rc4-40	40 bit RC4
aes-256-cbc	256 bit AES in CBC mode
aes-256-cfb	256 bit AES in 128 bit CFB mode
aes-256-cfb1	256 bit AES in 1 bit CFB mode
aes-256-cfb8	256 bit AES in 8 bit CFB mode
aes-256-ecb	256 bit AES in ECB mode
aes-256-ofb	256 bit AES in OFB mode
aes-192-cbc	192 bit AES in CBC mode
aes-192-cfb	192 bit AES in 128 bit CFB mode
aes-192-cfb1	192 bit AES in 1 bit CFB mode
aes-192-cfb8	192 bit AES in 8 bit CFB mode
aes-192-ecb	192 bit AES in ECB mode
aes-192-ofb	192 bit AES in OFB mode
aes-128-cbc	128 bit AES in CBC mode
aes-128-cfb	128 bit AES in 128 bit CFB mode
aes-128-cfb1	128 bit AES in 1 bit CFB mode
aes-128-cfb8	128 bit AES in 8 bit CFB mode
aes-128-ecb	128 bit AES in ECB mode
aes-128-ofb	128 bit AES in OFB mode

RSA Encryption¶

rsa_gen_key¶

Generate an RSA key pair.

Usage:

                          var crypto = require("rampart-crypto");

var key = crypto.rsa_gen_key([bits][, password]);

Where:

bits is a Number such as 1024, 2048 4096 or 8192. The number of modulus bits. Default is 4096 if not specified.

password is an optional String, a password to encrypt the private key.

Return Value:

An Object with the following properties:

public - the public key in pkcs8 pem format.

private - the private key in pkcs8 pem format, encrypted if password is given.

rsa_public - the public key in pkcs1 rsa public key pem format.

rsa_private - the private key in pkcs1 rsa private key pem format, encrypted if password is given.

Example:

                          var crypto = require("rampart-crypto");

/* for demo - generally should be 2048 or greater */
var key = crypto.rsa_gen_key(1024, "mypass");

rampart.utils.printf( "%s\n%s\n%s\n%s\n",
   key.private,
   key.public,
   key.rsa_private,
   key.rsa_public
);

/* expect output similar to the following:
-----BEGIN ENCRYPTED PRIVATE KEY-----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-----END ENCRYPTED PRIVATE KEY-----

-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC7lkrZ6gREJZT6ZWjvFxrm+lPY
dyE1uplaTbV87AirYHfQRTef3y87B/yL/Qud3brcPUePryqNz20wxZk8hDe0PAHC
IcM1c3STPxAvo+YJXbjt6DmoC+UK9nkIKXLg1lR9VMVYr9Gri8KWmyXAxHdmTSpf
njNlXdlur240f9negQIDAQAB
-----END PUBLIC KEY-----

-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AES-256-CBC,19216181CEB7C4E59C2D9B8F1F8E4323
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-----END RSA PRIVATE KEY-----

-----BEGIN RSA PUBLIC KEY-----
MIGJAoGBALuWStnqBEQllPplaO8XGub6U9h3ITW6mVpNtXzsCKtgd9BFN5/fLzsH
/Iv9C53dutw9R4+vKo3PbTDFmTyEN7Q8AcIhwzVzdJM/EC+j5glduO3oOagL5Qr2
eQgpcuDWVH1UxViv0auLwpabJcDEd2ZNKl+eM2Vd2W6vbjR/2d6BAgMBAAE=
-----END RSA PUBLIC KEY-----

*/

                        

rsa_import_priv_key¶

Import an existing private key and generate a new public and private keys.

Usage:

                          var crypto = require("rampart-crypto");

var key = crypto.rsa_import_priv_key(oldprivate_key[, opts]);

/* or */

var key = crypto.rsa_import_priv_key(oldprivate_key[, oldpass][, newpass]);

Where:

oldprivate_key is an Object or String, the pem formatted private key.

opts is an Object with the properties {decryptPassword: "oldpass", encryptPassword: "newpass"}.

oldpass is a String, the password to decrypt oldprivate_key, if encrypted.

newpass is a String, an optional password to encrypt the return private keys.

Return Value:

An Object with the following properties:

public - the public key in pkcs8 pem format.

private - the private key in pkcs8 pem format, encrypted if newpass is given.

rsa_public - the public key in pkcs1 rsa public key pem format.

rsa_private - the private key in pkcs1 rsa private key pem format, encrypted if newpass is given.

rsa_components¶

Get the component parts of an RSA public or private key.

Usage:

                          var crypto = require("rampart-crypto");

var components = crypto.rsa_components(key);

Return Value:

An Object.

If key is a public key, the following properties are set:

exponent - a String with the hex encoded value of the exponent.

modulus - a String with the hex encoded value of the modulus.

If key is a private key, in addition to the above:

privateExponent - a String with the hex encoded value of the private exponent.

privateFactorq - a String with the hex encoded value of the private factor q.

privateFactorp - a String with the hex encoded value of the private factor p.

rsa_pub_encrypt¶

Encrypt data using an RSA public key. The public key can be in either pem format generated by rsa_gen_key().

Usage:

                          var crypto = require("rampart-crypto");

var res = crypto.rsa_pub_encrypt(data, public_key[, paddingMode]);

Where:

data is a String or Buffer with the content to encrypt.

public_key is a String or Buffer with the content of the public key.

paddingMode is an optiona String that is one of the following (as described here):

"pkcs" - default if not specified. Use PKCS #1 v1.5 padding. This currently is the most widely used mode.

"oaep" - Use EME-OAEP as defined in PKCS #1 v2.0 with SHA-1, MGF1 and an empty encoding parameter. This mode is recommended for all new applications.

"ssl" - PKCS #1 v1.5 padding with an SSL-specific modification that denotes that the server is SSL3 capable.

"raw" - Raw RSA encryption. This mode should only be used to implement cryptographically sound padding modes in the application code. Encrypting user data directly with RSA is insecure.

Note that Openssl Library includes this warning:

“Decryption failures in the RSA_PKCS1_PADDING mode leak information which can potentially be used to mount a Bleichenbacher padding oracle attack. This is an inherent weakness in the PKCS #1 v1.5 padding design. Prefer RSA_PKCS1_OAEP_PADDING.” - see this document.

Note also that the length of data cannot be more than the number of bytes of the modulus used to create the key pair minus 11 (or minus 42 in the case of "oaep", or minus 0 in the case of raw).

Return Value:: A Buffer containing the encrypted text.

Example:

                          var crypto = require("rampart-crypto");

var data = ""
var str  = "contents of my potentially long data file...\n";

/* make content longer than can fit in rsa encrypted text */
for (i=0; i<100; i++)
    data+=str;

/* seed the random number generator before use */
crypto.seed();

/* generate random data and base64 encode for easy use*/
var symmetric_passwd = rampart.utils.sprintf("%B", crypto.rand(48));

/* encrypt data using the random base64 data as the password */
var ciphertext = crypto.encrypt(symmetric_passwd, data);

/* rsa encrypt the password with public key */
var encrypted_passwd = crypto.rsa_pub_encrypt(
    symmetric_passwd,
    rampart.utils.readFile("pubkey.pem")
);

/* transmit ciphertext and encrypted password to
   owner of the corresponding private key        */

                        

rsa_priv_decrypt¶

Decrypt encrypted data using an RSA private key. The private key can be in either pem format generated by rsa_gen_key().

Usage:

                          var crypto = require("rampart-crypto");

var res = crypto.rsa_priv_decrypt(data, private_key[, paddingMode][, password]);

Where:

data is a String or Buffer with the content to decrypt.

private_key is a String or Buffer with the contents of the private key.

paddingMode - a String. See above - the same padding mode used to encrypt the data.

password - a String, if private_key is password protected, the password used to encrypt the private key.

Return Value:: A Buffer containing the decrypted text.

Example:

                          /* continuing example from above, owner of privatekey.pem can do this */
var crypto = require("rampart-crypto");

/* receive ciphertext and encrypted password from above */

symmetric_passwd = crypto.rsa_priv_decrypt(
    encrypted_passwd,
    rampart.utils.readFile("privatekey.pem"),
    null, /* use default "pkcs" */
    "mysecretpassword"
);

/* decrypt message
   password must be a string */
var plaintext = crypto.decrypt(
    rampart.utils.bufferToString(symmetric_passwd),
    ciphertext
);

rampart.utils.printf("%s", plaintext);

/* expected output:
contents of my potentially long data file...
contents of my potentially long data file...
...
contents of my potentially long data file...
*/

                        

rsa_sign¶

Sign a message with an RSA private key. The private key can be in either pem format generated by rsa_gen_key().

Usage:

                          var crypto = require("rampart-crypto");

var signature = crypto.rsa_sign(message, private_key[, password]);

Where:

message is a String or Buffer with the content to sign.

private_key is a String or Buffer with the contents of the private key.

password - a String, if private_key is password protected, the password used to encrypt the private key.

Return Value:: A Buffer with the content of the signature. Same as openssl dgst -sha256 -sign private_key.pem -out sig msg.txt

rsa_verify¶

Verify a signed message with an RSA public key. The public key can be in either pem format generated by rsa_gen_key().

Usage:

                          var crypto = require("rampart-crypto");

var verified = crypto.rsa_verify(data, public_key, signature);

Where:

data is a String or Buffer with the content to verify.

public_key is a String or Buffer with the contents of the public key.

signature - a Buffer containing the signature generated with rsa_sign above, or with openssl.

Return Value:: A Boolean - true if verification succeeded. Otherwise false. Same as openssl dgst -sha256 -verify public_key.pem -signature sig msg.txt.

gen_csr¶

Generate a certificate signing request.

Usage:

                          var crypto = require("rampart-crypto");

var csr = crypto.gen_csr(private_key, opts[, password]);

Where:

private_key is a String, a pem formatted private key.

opts is an Object, with the following optional property Strings:

name - The “Common Name”, usually the relevant domain name.

country - A two letter country code (i.e. US or DE).

state - State or Province name.

city - The locality or city of your organization.

organization - The full legal name of your organization.

organizationUnit - The department of your organization.

email - Contact email.

subjectAltName - text to be placed in the Attributes -> Requested Extensions -> X509v3 Subject Alternative Name section of the certificate request. Also accepts an Array of Strings for multiple values.

subjectAltNameType - The type used for values in subjectAltName. If, e.g., dns is set and subjectAltName is set to ["example.com", "www.example.com"], the certificate signing request will include the X509v3 Subject Alternative Name value of DNS:example.com, DNS:www.example.com. Possible values are dns (the default if not specified), ip, email, uri, x400, dirname, rid or othername (case insensitive). See openssl documentation for meaning and usage of each. For requesting an SSL/TLS certificate for a webserver, dns should be used, particularly where the requested certificate will cover more than one domain name.

password - if private_key is password protected, the password to decrypt the private key.

Return Value:

A Object with the following properties:

pem - A String - the generated certificate signing request in pem format.

der - A Buffer - the generated certificate signing request in der binary format.

Example:

                          var crypto = require("rampart-crypto");

/* generate a server key */
var key = crypto.rsa_gen_key(4096 /* ,"password" */);

/* save it for use with webserver */
rampart.utils.fprintf("./server.key", '%s', key.private);

/* generate a signing request for current domains */
var csr = crypto.gen_csr(
    key.private,
    {
        name: "example.com",
        subjectAltName: ["example.com", "www.example.com"]
    }
    /* , "password" */
);
/* csr == {pem: pem_formatted_csr, der: der_formatted_csr} */

                        

Hashing¶

hash¶

The hash() function calculates a hash of the data in a String or Buffer and returns it in a hex encoded String or as binary data in a Buffer.

Usage:

                          var crypto = require("rampart-crypto");

var res = hash(data[, hash_func][, return_buffer]);

Where:

data is a String or Buffer, the data to be hashed.
hash_func is an optional String, one of the following:

sha1, sha224, sha256, sha384, sha512, md4, md5, sha3-224, sha3-256, sha3-384, sha3-512, blake2b512, blake2s256, mdc2, rmd160, sha512-224, sha512-256, shake128, shake256, sm3. Default is sha256.
return_buffer is a Boolean, if true, the output will be binary data in a Buffer, and not hex encoded.

Return Value:: A String or Buffer, the hash of the data.

Example:

                          var crypto = require("rampart-crypto");

var res = crypto.hash("hello world", "sha256");

/*
    res == 'b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9'
*/

alias functions¶

The hash function has an alias for each of the possible hash_func value above. Thus, using crypto.hash("hello world", "sha256") is equivalent to crypto.sha256("hello world"). For hash_func names with a dash (-), an underscore (_) is used instead. Thus crypto.hash("hello world", "sha3-256") is equivalent to crypto.sha3_256("hello world").

hmac¶

The hmac() function computes a HMAC from the provided data and key.

Usage:

                          var crypto = require("rampart-crypto");

var res = crypto.hmac(secret, data[, hash_func][, return_buffer]);

Where:

secret is the HMAC function key.

data is a String or Buffer, the data to be hashed.

hash_func is an optional String, one of the following:

sha1, sha224, sha256, sha384, sha512, md4, md5, sha3-224, sha3-256, sha3-384, sha3-512, blake2b512, blake2s256, mdc2, rmd160, sha512-224, sha512-256, sm3. Default is sha256.

return_buffer is a Boolean, if true, the output will be binary data in a Buffer, and not hex encoded.

Return Value:: A String or Buffer, the hmac hash of the data.

Random¶

rand¶

The rand() function returns random generated bytes in a buffer.

Usage:

                          var crypto = require("rampart-crypto");

var res = crypto.rand(nBytes);

Where nBytes is the number of bytes to return.

Return Value:: a Buffer with nBytes bytes of random data.

randnum¶

The randnum() function returns a random Number between 0.0 and 1.0.

gaussrand¶

The gaussrand([sigma]) function returns a random Number based on a normal distribution centered at zero (0.0), where sigma is one standard deviation. sigma is optional, defaulting to 1.0.

normrand¶

The normrand([scale]) function returns a random Number based on a normal distribution centered at zero (0.0) and clamped between -scale and scale.

Similar to the gaussrand above. It is equivelant to:

                          var nrand = scale * crypto.gaussrand(1.0)/5.0;

if(nrand>scale)
    nrand=scale;
else if (nrand < -scale)
    nrand = -scale;

                        

With a scale of 1.0 (the default), the distribution of numbers has a standard deviation of 0.2.

seed¶

The seed() function seeds the random number generator from a file. There is no return value.

Usage:

                          var crypto = require("rampart-crypto");

var res = crypto.seed([options]);

Where options is an Object, if provided, and contains the following properties:

file - a String - location of the file. Default is /dev/urandom.
bytes - a Number - Number of bytes to retrieve from file. Default is 32.

BigInt¶

The rampart-crypto module includes functions which handle arbitrarily long integers using openssl’s BIGNUM library. It is designed to be compatible with the JSBI library and includes the same published functions. See JSBI Node Module for more information.

Usage as documented below is as such:

                        var crypto = require("rampart-crypto");

var JSBI = crypto.JSBI;

JSBI.BigInt¶

Create a BigInt from a String or Number.

Possible Strings:

1234
-1234
0x123e
-0x123e
-0b11110011
-0b11110011

Example:

                          var crypto = require("rampart-crypto");

var JSBI = crypto.JSBI;

var mybignum = JSBI.BigInt("123456789012345678901234567890");

JSBI Compatible functions¶

JSBI functions aspire to operate in a manner that mirrors the JSBI library. Please see that library for details. Available commands include:

JSBI.BigInt(num).toString(), JSBI.toNumber(), JSBI.asIntN(), JSBI.asUintN(), a instanceof JSBI, JSBI.add(), JSBI.subtract(), JSBI.multiply(), JSBI.divide(), JSBI.remainder(), JSBI.exponentiate(), JSBI.unaryMinus(), JSBI.bitwiseNot(), JSBI.leftShift(), JSBI.signedRightShift(), JSBI.bitwiseAnd(), JSBI.bitwiseOr(), JSBI.bitwiseXor(), JSBI.equal(), JSBI.notEqual(), JSBI.lessThan(), JSBI.lessThanOrEqual(), JSBI.greaterThan(), JSBI.greaterThanOrEqual(), JSBI.EQ(), JSBI.NE(), JSBI.LT(), JSBI.LE(), JSBI.GT(), JSBI.GE(), JSBI.ADD().

Note that in rampart, JSBI.BigInt().toString() only accepts 2, 10 and 16 as possible arguments, with 10 being the default.

toSignedString¶

JSBI.BigInt().toSignedString() will convert a BigInt into a string representing the equivalent signed number. This differs from JSBI.BigInt().toString() only when used for a signed binary integer (using JSBI.BigInt(num).toSignedString(2)).

Example:

                          var crypto = require("rampart-crypto");

var JSBI = crypto.JSBI;

var mybignum = JSBI.BigInt("-256");

console.log( mybignum.toString(2) );

console.log( mybignum.toSignedString(2) );

/* expected output:

-100000000
1111111100000000

*/