source: trip-planner-front/node_modules/sshpk/lib/formats/ssh.js@ ceaed42

// Copyright 2015 Joyent, Inc.

module.exports = {
        read: read,
        write: write
};

var assert = require('assert-plus');
var Buffer = require('safer-buffer').Buffer;
var rfc4253 = require('./rfc4253');
var utils = require('../utils');
var Key = require('../key');
var PrivateKey = require('../private-key');

var sshpriv = require('./ssh-private');

/*JSSTYLED*/
var SSHKEY_RE = /^([a-z0-9-]+)[ \t]+([a-zA-Z0-9+\/]+[=]*)([ \t]+([^ \t][^\n]*[\n]*)?)?$/;
/*JSSTYLED*/
var SSHKEY_RE2 = /^([a-z0-9-]+)[ \t\n]+([a-zA-Z0-9+\/][a-zA-Z0-9+\/ \t\n=]*)([^a-zA-Z0-9+\/ \t\n=].*)?$/;

function read(buf, options) {
        if (typeof (buf) !== 'string') {
                assert.buffer(buf, 'buf');
                buf = buf.toString('ascii');
        }

        var trimmed = buf.trim().replace(/[\\\r]/g, '');
        var m = trimmed.match(SSHKEY_RE);
        if (!m)
                m = trimmed.match(SSHKEY_RE2);
        assert.ok(m, 'key must match regex');

        var type = rfc4253.algToKeyType(m[1]);
        var kbuf = Buffer.from(m[2], 'base64');

        /*
         * This is a bit tricky. If we managed to parse the key and locate the
         * key comment with the regex, then do a non-partial read and assert
         * that we have consumed all bytes. If we couldn't locate the key
         * comment, though, there may be whitespace shenanigans going on that
         * have conjoined the comment to the rest of the key. We do a partial
         * read in this case to try to make the best out of a sorry situation.
         */
        var key;
        var ret = {};
        if (m[4]) {
                try {
                        key = rfc4253.read(kbuf);

                } catch (e) {
                        m = trimmed.match(SSHKEY_RE2);
                        assert.ok(m, 'key must match regex');
                        kbuf = Buffer.from(m[2], 'base64');
                        key = rfc4253.readInternal(ret, 'public', kbuf);
                }
        } else {
                key = rfc4253.readInternal(ret, 'public', kbuf);
        }

        assert.strictEqual(type, key.type);

        if (m[4] && m[4].length > 0) {
                key.comment = m[4];

        } else if (ret.consumed) {
                /*
                 * Now the magic: trying to recover the key comment when it's
                 * gotten conjoined to the key or otherwise shenanigan'd.
                 *
                 * Work out how much base64 we used, then drop all non-base64
                 * chars from the beginning up to this point in the the string.
                 * Then offset in this and try to make up for missing = chars.
                 */
                var data = m[2] + (m[3] ? m[3] : '');
                var realOffset = Math.ceil(ret.consumed / 3) * 4;
                data = data.slice(0, realOffset - 2). /*JSSTYLED*/
                    replace(/[^a-zA-Z0-9+\/=]/g, '') +
                    data.slice(realOffset - 2);

                var padding = ret.consumed % 3;
                if (padding > 0 &&
                    data.slice(realOffset - 1, realOffset) !== '=')
                        realOffset--;
                while (data.slice(realOffset, realOffset + 1) === '=')
                        realOffset++;

                /* Finally, grab what we think is the comment & clean it up. */
                var trailer = data.slice(realOffset);
                trailer = trailer.replace(/[\r\n]/g, ' ').
                    replace(/^\s+/, '');
                if (trailer.match(/^[a-zA-Z0-9]/))
                        key.comment = trailer;
        }

        return (key);
}

function write(key, options) {
        assert.object(key);
        if (!Key.isKey(key))
                throw (new Error('Must be a public key'));

        var parts = [];
        var alg = rfc4253.keyTypeToAlg(key);
        parts.push(alg);

        var buf = rfc4253.write(key);
        parts.push(buf.toString('base64'));

        if (key.comment)
                parts.push(key.comment);

        return (Buffer.from(parts.join(' ')));
}