81 lines
2.0 KiB
JavaScript
81 lines
2.0 KiB
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));
|
|
var el;
|
|
|
|
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;
|
|
el = buf.slice(index, index + len);
|
|
// remove BigUInt '00' prefix
|
|
if (0x00 === el[0]) {
|
|
el = el.slice(1);
|
|
}
|
|
els.push(el);
|
|
index += len;
|
|
}
|
|
|
|
jwk.n = Enc.bufToUrlBase64(els[2]);
|
|
jwk.e = Enc.bufToUrlBase64(els[1]);
|
|
|
|
return jwk;
|
|
};
|
|
|
|
SSH.pack = function (opts) {
|
|
var jwk = opts.jwk;
|
|
var header = 'ssh-rsa';
|
|
var comment = opts.comment || 'rsa@localhost';
|
|
var e = SSH._padHexInt(Enc.base64ToHex(jwk.e));
|
|
var n = SSH._padHexInt(Enc.base64ToHex(jwk.n));
|
|
var hex = [
|
|
SSH._numToUint32Hex(header.length)
|
|
, Enc.strToHex(header)
|
|
, SSH._numToUint32Hex(e.length/2)
|
|
, e
|
|
, SSH._numToUint32Hex(n.length/2)
|
|
, n
|
|
].join('');
|
|
return [ header, Enc.hexToBase64(hex), comment ].join(' ');
|
|
};
|
|
|
|
SSH._numToUint32Hex = function (num) {
|
|
var hex = num.toString(16);
|
|
while (hex.length < 8) {
|
|
hex = '0' + hex;
|
|
}
|
|
return hex;
|
|
};
|
|
|
|
SSH._padHexInt = function (hex) {
|
|
// BigInt is negative if the high order bit 0x80 is set,
|
|
// so ASN1, SSH, and many other formats pad with '0x00'
|
|
// to signifiy a positive number.
|
|
var i = parseInt(hex.slice(0, 2), 16);
|
|
if (0x80 & i) {
|
|
return '00' + hex;
|
|
}
|
|
return hex;
|
|
};
|