Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
function safe64(data) {
if ( !Buffer.isBuffer(data) ) {
if (typeof data !== 'string') {
data = Buffer.from(JSON.stringify(data)).toString('base64');
}
} else {
data = data.toString('base64');
}
return data.replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/g, '');
}
function text2hex(txt) {
for (var n = 0, hex = ''; n < txt.length; n++) {
hex += ('0' + Number(txt.charCodeAt(n)).toString(16)).slice(-2);
}
return hex;
}
function hexLength(length) {
length = '0' + Number(length / 2).toString(16);
length = length.slice(-(length.length - length.length % 2));
return length;
}
function ecdsa(d, x, y) {
if (!d || !x || !y) {
const ecdh = crypto.createECDH('prime256v1');
ecdh.generateKeys();
d = ecdh.getPrivateKey();
x = ecdh.getPublicKey().slice(1, 33);
y = ecdh.getPublicKey().slice(33);
}
this.d = d;
this.x = x;
this.y = y;
}
ecdsa.prototype.sign = function sign(message, isRaw) {
const signer = crypto.createSign('RSA-SHA256');
signer.update(message);
signer.end();
if (isRaw) {
return signer.sign(this.toPEM());
}
var signature = signer.sign(this.toPEM()),
rLength = parseInt(signature.slice(3, 4).toString('hex'), 16),
r = signature.slice(4, 4 + rLength),
sLength = parseInt(signature.slice(5 + rLength, 6 + rLength).toString('hex'), 16),
s = signature.slice(6 + rLength, 6 + rLength + sLength);
while(r[0] == 0) { r = r.slice(1); }
while(s[0] == 0) { s = s.slice(1); }
return Buffer.concat([ r, s ]);
}
ecdsa.prototype.toCSR = function toCSR(domain, isRaw) {
var domainHex = text2hex(domain),
segments = Buffer.from('3082' + hexLength(domainHex.length + 488) +
'0201003081' + hexLength(domainHex.length + 290) +
'310B' +
'30090603550406130241523115301306' +
'035504080C0C4275656E6F7320416972' +
'65733112301006035504070C09436869' +
'76696C636F793110300E060355040A0C' +
'0743726176696E673111300F06035504' +
'0B0C08536F66747761726531' + hexLength(domainHex.length + 18) +
'30' + hexLength(domainHex.length + 14) + '06' +
'03550403' +
'0C' + hexLength(domainHex.length) + domainHex +
'3127302506092A864886F70D' +
'01090116187765626D61737465724063' +
'726176696E672E636F6D2E6172305930' +
'1306072A8648CE3D020106082A8648CE' +
'3D03010703420004' +
this.x.toString('hex') +
this.y.toString('hex') +
'A000', 'hex'),
signature = this.sign(segments, true).toString('hex'),
content = segments.toString('hex') +
'300A06082A8648CE3D04030203' + hexLength(signature.length + 2) + '00' +
signature,
certificate = Buffer.from('3082' + hexLength(content.length) + content, 'hex').toString('base64'),
csr = '-----BEGIN CERTIFICATE REQUEST-----\n' +
certificate.match(/.{1,64}/g)
.join('\n') + '\n' +
'-----END CERTIFICATE REQUEST-----';
fs.writeFileSync(domain.replace(/\*/g, '()') + '.csr', csr);
if (isRaw) {
return safe64(certificate);
}
return csr;
}
ecdsa.prototype.toThumbprint = function toThumbprint() {
return safe64(crypto.createHash('sha256').update(JSON.stringify(this.toJWK(true))).digest('base64'));
}
ecdsa.prototype.toJWK = function toJWK(isPublic) {
var jwk = {
crv: 'P-256',
d: safe64(this.x),
kty: 'EC',
x: safe64(this.x),
y: safe64(this.y)
}
if (isPublic) {
delete jwk.d;
}
return jwk;
}
ecdsa.prototype.toPEM = function toPEM() {
return '-----BEGIN EC PRIVATE KEY-----\n' +
Buffer.from('30770201010420' +
this.d.toString('hex') +
'A00A06082A8648CE3D030107A144034200' +
Buffer.concat([ Buffer.from([0x04]), this.x, this.y ]).toString('hex'), 'hex')
.toString('base64')
.match(/.{1,64}/g)
.join('\n') + '\n' +
'-----END EC PRIVATE KEY-----';
}
//----
var myKey = new ecdsa();
console.log(myKey.toCSR('example.com'));
@coolaj86
Copy link

coolaj86 commented Nov 10, 2018

Did you ever figure out how to do multiple domain names? Or RSA?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment