pem

Create private keys and certificates with node.js

Installation

Install with npm

npm install pem

Examples

Here are some examples for creating an SSL key/cert on the fly, and running an HTTPS server on port 443. 443 is the standard HTTPS port, but requires root permissions on most systems. To get around this, you could use a higher port number, like 4300, and use https://localhost:4300 to access your server.

Basic https

var https = require('https'),
    pem = require('pem');

pem.createCertificate({days:1, selfSigned:true}, function(err, keys){
    https.createServer({key: keys.serviceKey, cert: keys.certificate}, function(req, res){
        res.end('o hai!')
    }).listen(443);
});

Express

var https = require('https'),
    pem = require('pem'),
    express = require('express');

pem.createCertificate({days:1, selfSigned:true}, function(err, keys){
  var app = express();

  app.get('/',  function(req, res){
    res.send('o hai!');
  });

  https.createServer({key: keys.serviceKey, cert: keys.certificate}, app).listen(443);
});

API

Create a dhparam key

Use createDhparam for creating dhparam keys

pem.createDhparam(keyBitsize, callback)

Where

• keyBitsize is an optional size of the key, defaults to 512 (bit)
• callback is a callback function with an error object and {dhparam}

Create a private key

Use createPrivateKey for creating private keys

pem.createPrivateKey(keyBitsize, [options,] callback)

Where

• keyBitsize is an optional size of the key, defaults to 2048 (bit)
• options is an optional object of the cipher and password (both required for encryption), defaults {cipher:'',password:''} (ciphers:["aes128", "aes192", "aes256", "camellia128", "camellia192", "camellia256", "des", "des3", "idea"])
• callback is a callback function with an error object and {key}

Create a Certificate Signing Request

Use createCSR for creating certificate signing requests

pem.createCSR(options, callback)

Where

• options is an optional options object
• callback is a callback function with an error object and {csr, clientKey}

Possible options are the following

• clientKey is an optional client key to use
• clientKeyPassword the optional password for clientKey
• keyBitsize - if clientKey is undefined, bit size to use for generating a new key (defaults to 2048)
• hash is a hash function to use (either md5, sha1 or sha256, defaults to sha256)
• country is a CSR country field
• state is a CSR state field
• locality is a CSR locality field
• organization is a CSR organization field
• organizationUnit is a CSR organizational unit field
• commonName is a CSR common name field (defaults to localhost)
• altNames is a list (Array) of subjectAltNames in the subjectAltName field (optional)
• emailAddress is a CSR email address field
• csrConfigFile is a CSR config file

Create a certificate

Use createCertificate for creating private keys

pem.createCertificate(options, callback)

Where

• options is an optional options object
• callback is a callback function with an error object and {certificate, csr, clientKey, serviceKey}

Possible options include all the options for createCSR - in case csr parameter is not defined and a new CSR needs to be generated.

In addition, possible options are the following

• serviceKey is a private key for signing the certificate, if not defined a new one is generated
• serviceKeyPassword Password of the service key
• serviceCertificate is the optional certificate for the serviceKey
• serial is the unique serial number for the signed certificate, required if serviceCertificate is defined
• selfSigned - if set to true and serviceKey is not defined, use clientKey for signing
• csr is a CSR for the certificate, if not defined a new one is generated
• days is the certificate expire time in days
• extFile extension config file - without -extensions v3_req
• config extension config file - with -extensions v3_req

Export a public key

Use getPublicKey for exporting a public key from a private key, CSR or certificate

pem.getPublicKey(certificate, callback)

Where

• certificate is a PEM encoded private key, CSR or certificate
• callback is a callback function with an error object and {publicKey}

Read certificate info

Use readCertificateInfo for reading subject data from a certificate or a CSR

pem.readCertificateInfo(certificate, callback)

Where

• certificate is a PEM encoded CSR or a certificate
• callback is a callback function with an error object and {serial, country, state, locality, organization, organizationUnit, commonName, emailAddress, validity{start, end}, san{dns, ip}?, issuer{country, state, locality, organization, organizationUnit}, signatureAlgorithm, publicKeyAlgorithm, publicKeySize }

? san is only present if the CSR or certificate has SAN entries.

signatureAlgorithm, publicKeyAlgorithm and publicKeySize only available if supportet and can parsed form openssl output

Get fingerprint

Use getFingerprint to get the default SHA1 fingerprint for a certificate

pem.getFingerprint(certificate, [hash], callback)

Where

• certificate is a PEM encoded certificate
• hash is a hash function to use (either md5, sha1 or sha256, defaults to sha1)
• callback is a callback function with an error object and {fingerprint}

Get modulus

Use getModulus to get the modulus for a certificate, a CSR or a private key. Modulus can be useful to check that a Private Key Matches a Certificate

pem.getModulus(certificate, [password], [hash], callback)

Where

• certificate is a PEM encoded certificate, CSR or private key
• password is an optional passphrase for passpharse protected certificates
• hash is an optional hash function to use (up to now md5 supported) (default: none)
• callback is a callback function with an error object and {modulus}

Get DH parameter information

Use getDhparamInfo to get the size and prime of DH parameters.

pem.getDhparamInfo(dhparam, callback)

Where

• dhparam is a PEM encoded DH parameters string
• callback is a callback function with an error object and {size, prime}

Export to a PKCS12 keystore

Use createPkcs12 to export a certificate, the private key and optionally any signing or intermediate CA certificates to a PKCS12 keystore.

pem.createPkcs12(clientKey, certificate, p12Password, [options], callback)

Where

• clientKey is a PEM encoded private key
• certificate is a PEM encoded certificate
• p12Password is the password of the exported keystore
• options is an optional options object with cipher, (one of "aes128", "aes192", "aes256", "camellia128", "camellia192", "camellia256", "des", "des3" or "idea"), clientKeyPassword and certFiles (an array of additional certificates to include - e.g. CA certificates)
• callback is a callback function with an error object and {pkcs12} (binary)

Read a PKCS12 keystore

Use readPkcs12 to read a certificate, private key and CA certificates from a PKCS12 keystore.

pem.readPkcs12(bufferOrPath, [options], callback)

Where

• bufferOrPath is a PKCS12 keystore as a Buffer or the path to a file
• options is an optional options object with clientKeyPassword which will be used to encrypt the stored key and p12Password which will be used to open the keystore
• callback is a callback function with an error object and {key: String, cert: String, ca: Array}

Check a PKCS12 keystore

Use checkPkcs12 to check a PKCS12 keystore.

pem.checkPkcs12(bufferOrPath, [passphrase], callback)

Where

• bufferOrPath is a PKCS12 keystore as a Buffer or the path to a file
• passphrase is an optional passphrase which will be used to open the keystore
• callback is a callback function with an error object and a boolean as arguments

### Verify a certificate signing chain

Use verifySigningChain to assert that a given certificate has a valid signing chain.

pem.verifySigningChain(certificate, ca, callback)

Where

• certificate is a PEM encoded certificate string
• ca is a PEM encoded CA certificate string or an array of certificate strings
• callback is a callback function with an error object and a boolean as arguments

### Check a certificate file

Use checkCertificate to check / verify consistency of a certificate.

pem.checkCertificate(certificate, callback)

Where

• certificate is a PEM encoded certificate string
• callback is a callback function with an error object and a boolean as arguments

### Custom extensions config file

You can specify custom OpenSSL extensions using the config or extFile options for createCertificate (or using csrConfigFile with createCSR).

extFile and csrConfigFile should be paths to the extension files. While config will generate a temporary file from the supplied file contents.

If you specify config then the v3_req section of your config file will be used.

The following would be an example of a Certificate Authority extensions file:

[req]
req_extensions = v3_req
distinguished_name = req_distinguished_name

[req_distinguished_name]
commonName = Common Name
commonName_max = 64

[v3_req]
basicConstraints = critical,CA:TRUE

While the following would specify subjectAltNames in the resulting certificate:

[req]
req_extensions = v3_req

[ v3_req ]
basicConstraints = CA:FALSE
keyUsage = nonRepudiation, digitalSignature, keyEncipherment
subjectAltName = @alt_names

[alt_names]
DNS.1 = host1.example.com
DNS.2 = host2.example.com
DNS.3 = host3.example.com

Note that createCertificate and createCSR supports the altNames option which would be easier to use in most cases.

Warning: If you specify altNames the custom extensions file will not be passed to OpenSSL.

Setting openssl location

In some systems the openssl executable might not be available by the default name or it is not included in $PATH. In this case you can define the location of the executable yourself as a one time action after you have loaded the pem module:

var pem = require('pem');
pem.config({
    pathOpenSSL: '/usr/local/bin/openssl'
});
...
// do something with the pem module

Specialthanks to

• Andris Reinman (@andris9) - Initiator of pem

License

MIT