v1.2.11: convert ECDSA ASN.1 signature to ECDSA JWT type

This commit is contained in:
AJ ONeal 2019-03-08 16:46:50 -07:00
parent e04557c84a
commit 65db78a3c5
3 changed files with 42 additions and 4 deletions

View File

@ -229,13 +229,21 @@ Keypairs.signJws = function (opts) {
} }
// node specifies RSA-SHAxxx even whet it's actually ecdsa (it's all encoded x509 shasums anyway) // node specifies RSA-SHAxxx even whet it's actually ecdsa (it's all encoded x509 shasums anyway)
var nodeAlg = "RSA-SHA" + (((protect||header).alg||'').replace(/^[^\d]+/, '')||'256'); var nodeAlg = "SHA" + (((protect||header).alg||'').replace(/^[^\d]+/, '')||'256');
var protected64 = Enc.strToUrlBase64(protectedHeader); var protected64 = Enc.strToUrlBase64(protectedHeader);
var payload64 = Enc.bufToUrlBase64(payload); var payload64 = Enc.bufToUrlBase64(payload);
var sig = require('crypto') var binsig = require('crypto')
.createSign(nodeAlg) .createSign(nodeAlg)
.update(protect ? (protected64 + "." + payload64) : payload64) .update(protect ? (protected64 + "." + payload64) : payload64)
.sign(pem, 'base64') .sign(pem)
;
if (!opts.jwk || 'RSA' !== opts.jwk.kty) {
// ECDSA JWT signatures differ from "normal" ECDSA signatures
// https://tools.ietf.org/html/rfc7518#section-3.4
binsig = convertIfEcdsa(binsig);
}
var sig = binsig.toString('base64')
.replace(/\+/g, '-') .replace(/\+/g, '-')
.replace(/\//g, '_') .replace(/\//g, '_')
.replace(/=/g, '') .replace(/=/g, '')
@ -249,6 +257,35 @@ Keypairs.signJws = function (opts) {
}; };
} }
function convertIfEcdsa(binsig) {
// should have asn1 sequence header of 0x30
if (0x30 !== binsig[0]) { return binsig; }
var index = 2; // first ecdsa "R" header byte
var len = binsig[1];
var lenlen = 0;
// Seek length of length if length is greater than 127 (i.e. two 512-bit / 64-byte R and S values)
if (0x80 & len) {
lenlen = len - 0x80;
// the length of the signature won't be over 256 bytes (2048 bits) for many years yet
if (1 !== lenlen) { return binsig; }
// the length is this number
len = binsig[2];
index += lenlen;
}
// should have bigint header of 0x02 followd by a single byte of length
if (0x02 !== binsig[index]) { return binsig; }
index += 1;
var rlen = binsig[index];
var r = binsig.slice(index + 1, index + 1 + rlen);
var slen = binsig[index + 1 + rlen + 1]; // skip header and read length
var s = binsig.slice(index + 1 + rlen + 1 + 1);
if (slen !== s.byteLength) { return binsig; }
// There may be one byte of padding on either
if (33 === r.byteLength) { r = r.slice(1); }
if (33 === s.byteLength) { s = s.slice(1); }
return Buffer.concat([r, s]);
}
if (opts.pem && opts.jwk) { if (opts.pem && opts.jwk) {
return sign(opts.pem); return sign(opts.pem);
} else { } else {

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@ -1,6 +1,6 @@
{ {
"name": "keypairs", "name": "keypairs",
"version": "1.2.9", "version": "1.2.11",
"description": "Lightweight RSA/ECDSA keypair generation and JWK <-> PEM", "description": "Lightweight RSA/ECDSA keypair generation and JWK <-> PEM",
"main": "keypairs.js", "main": "keypairs.js",
"files": [ "files": [

View File

@ -1,6 +1,7 @@
var Keypairs = require('./'); var Keypairs = require('./');
/* global Promise*/ /* global Promise*/
console.info("This SHOULD result in an error message:");
Keypairs.parseOrGenerate({ key: '' }).then(function (pair) { Keypairs.parseOrGenerate({ key: '' }).then(function (pair) {
// should NOT have any warning output // should NOT have any warning output
if (!pair.private || !pair.public) { if (!pair.private || !pair.public) {