--- /dev/null
+// Copyright 2015 Joyent, Inc.
+
+module.exports = {
+ read: read,
+ write: write
+};
+
+var assert = require('assert-plus');
+var utils = require('../utils');
+var Key = require('../key');
+var PrivateKey = require('../private-key');
+
+var pem = require('./pem');
+var ssh = require('./ssh');
+var rfc4253 = require('./rfc4253');
+
+function read(buf, options) {
+ if (typeof (buf) === 'string') {
+ if (buf.trim().match(/^[-]+[ ]*BEGIN/))
+ return (pem.read(buf, options));
+ if (buf.match(/^\s*ssh-[a-z]/))
+ return (ssh.read(buf, options));
+ if (buf.match(/^\s*ecdsa-/))
+ return (ssh.read(buf, options));
+ buf = new Buffer(buf, 'binary');
+ } else {
+ assert.buffer(buf);
+ if (findPEMHeader(buf))
+ return (pem.read(buf, options));
+ if (findSSHHeader(buf))
+ return (ssh.read(buf, options));
+ }
+ if (buf.readUInt32BE(0) < buf.length)
+ return (rfc4253.read(buf, options));
+ throw (new Error('Failed to auto-detect format of key'));
+}
+
+function findSSHHeader(buf) {
+ var offset = 0;
+ while (offset < buf.length &&
+ (buf[offset] === 32 || buf[offset] === 10 || buf[offset] === 9))
+ ++offset;
+ if (offset + 4 <= buf.length &&
+ buf.slice(offset, offset + 4).toString('ascii') === 'ssh-')
+ return (true);
+ if (offset + 6 <= buf.length &&
+ buf.slice(offset, offset + 6).toString('ascii') === 'ecdsa-')
+ return (true);
+ return (false);
+}
+
+function findPEMHeader(buf) {
+ var offset = 0;
+ while (offset < buf.length &&
+ (buf[offset] === 32 || buf[offset] === 10))
+ ++offset;
+ if (buf[offset] !== 45)
+ return (false);
+ while (offset < buf.length &&
+ (buf[offset] === 45))
+ ++offset;
+ while (offset < buf.length &&
+ (buf[offset] === 32))
+ ++offset;
+ if (offset + 5 > buf.length ||
+ buf.slice(offset, offset + 5).toString('ascii') !== 'BEGIN')
+ return (false);
+ return (true);
+}
+
+function write(key, options) {
+ throw (new Error('"auto" format cannot be used for writing'));
+}