Make 'auto' format handle leading whitespace in ssh keys

lib/formats/auto.js

@@ -18,25 +18,37 @@ function read(buf) {
 	if (typeof (buf) === 'string') {
 		if (buf.trim().match(/^[-]+[ ]*BEGIN/))
 			return (pem.read(buf));
-		if (buf.match(/^ssh-[a-z]/))
+		if (buf.match(/^\s*ssh-[a-z]/))
 			return (ssh.read(buf));
-		if (buf.match(/^ecdsa-/))
+		if (buf.match(/^\s*ecdsa-/))
 			return (ssh.read(buf));
 		buf = new Buffer(buf, 'binary');
 	} else {
 		assert.buffer(buf);
 		if (findPEMHeader(buf))
 			return (pem.read(buf));
-		if (buf.slice(0, 4).toString('ascii') === 'ssh-')
-			return (ssh.read(buf));
-		if (buf.slice(0, 6).toString('ascii') === 'ecdsa-')
+		if (findSSHHeader(buf))
 			return (ssh.read(buf));
 	}
 	if (buf.readUInt32BE(0) < buf.length)
 		return (rfc4253.read(buf));
 	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 &&

test/pem.js

@@ -189,6 +189,12 @@ test('1024b rsa ssh key with whitespace', function(t) {
 	t.end();
 });
 
+test('1024b rsa ssh key with whitespace auto', function(t) {
+	var k = sshpk.parseKey('\n\t    \n' + SSH_1024 + '\n', 'auto');
+	t.equal(k.toString('pem'), PEM_1024);
+	t.end();
+});
+
 test('1024b rsa ssh key with inner whitespace', function(t) {
 	var k = sshpk.parseKey(SSH_1024_WS, 'ssh');
 	t.equal(k.comment, '[email protected]');