rasha-fork/lib/ssh.js

39 lines
1021 B
JavaScript

'use strict';
var SSH = module.exports;
var Enc = require('./encoding.js');
// 7 s s h - r s a
SSH.RSA = '00000007 73 73 68 2d 72 73 61'.replace(/\s+/g, '').toLowerCase();
SSH.parse = function (pem, jwk) {
var parts = pem.split(/\s+/);
var buf = Enc.base64ToBuf(parts[1]);
var els = [];
var index = 0;
var len;
var i = 0;
var offset = (buf.byteOffset || 0);
// using dataview to be browser-compatible (I do want _some_ code reuse)
var dv = new DataView(buf.buffer.slice(offset, offset + buf.byteLength));
if (SSH.RSA !== Enc.bufToHex(buf.slice(0, SSH.RSA.length/2))) {
throw new Error("does not lead with ssh header");
}
while (index < buf.byteLength) {
i += 1;
if (i > 3) { throw new Error("15+ elements, probably not a public ssh key"); }
len = dv.getUint32(index, false);
index += 4;
els.push(buf.slice(index, index + len));
index += len;
}
jwk.n = Enc.bufToUrlBase64(els[2]);
jwk.e = Enc.bufToUrlBase64(els[1]);
return jwk;
};