external/openssh: update to 6.8p1.

In preparation for some updates to external/openssh to make it work with
BoringSSL, this change updates the code to a recent version. The current
version (5.9p1) is coming up on four years old now.

  * Confirmed that f5c67b478bef9992de9e9ec91ce10af4f6205e0d matches
    OpenSSH 5.9p1 exactly (save for the removal of the scard
    subdirectory).

  * Downloaded openssh-6.8p1.tar.gz (SHA256:
    3ff64ce73ee124480b5bf767b9830d7d3c03bbcb6abe716b78f0192c37ce160e)
    and verified with PGP signature. (I've verified Damien's key in
    person previously.)

  * Applied changes between f5c67b478bef9992de9e9ec91ce10af4f6205e0d and
    OpenSSH 5.9p1 to 6.8p1 and updated the build as best I can. The
    ugliest change is probably the duplication of umac.c to umac128.c
    because Android conditionally compiles that file twice. See the
    comment in those files.

Change-Id: I63cb07a8118afb5a377f116087a0882914cea486
diff --git a/ssh-keyscan.1 b/ssh-keyscan.1
index fe9bb6e..6bbc480 100644
--- a/ssh-keyscan.1
+++ b/ssh-keyscan.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ssh-keyscan.1,v 1.29 2010/08/31 11:54:45 djm Exp $
+.\"	$OpenBSD: ssh-keyscan.1,v 1.36 2014/08/30 15:33:50 sobrado Exp $
 .\"
 .\" Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
 .\"
@@ -6,7 +6,7 @@
 .\" permitted provided that due credit is given to the author and the
 .\" OpenBSD project by leaving this copyright notice intact.
 .\"
-.Dd $Mdocdate: August 31 2010 $
+.Dd $Mdocdate: August 30 2014 $
 .Dt SSH-KEYSCAN 1
 .Os
 .Sh NAME
@@ -56,14 +56,16 @@
 to use IPv6 addresses only.
 .It Fl f Ar file
 Read hosts or
-.Pa addrlist namelist
-pairs from this file, one per line.
+.Dq addrlist namelist
+pairs from
+.Ar file ,
+one per line.
 If
 .Pa -
 is supplied instead of a filename,
 .Nm
 will read hosts or
-.Pa addrlist namelist
+.Dq addrlist namelist
 pairs from the standard input.
 .It Fl H
 Hash all hostnames and addresses in the output.
@@ -78,7 +80,7 @@
 .It Fl T Ar timeout
 Set the timeout for connection attempts.
 If
-.Pa timeout
+.Ar timeout
 seconds have elapsed since a connection was initiated to a host or since the
 last time anything was read from that host, then the connection is
 closed and the host in question considered unavailable.
@@ -89,13 +91,18 @@
 .Dq rsa1
 for protocol version 1 and
 .Dq dsa ,
-.Dq ecdsa
+.Dq ecdsa ,
+.Dq ed25519 ,
 or
 .Dq rsa
 for protocol version 2.
 Multiple values may be specified by separating them with commas.
-The default is
-.Dq rsa .
+The default is to fetch
+.Dq rsa ,
+.Dq ecdsa ,
+and
+.Dq ed25519
+keys.
 .It Fl v
 Verbose mode.
 Causes
@@ -113,37 +120,36 @@
 can help in the detection of tampered keyfiles or man in the middle
 attacks which have begun after the ssh_known_hosts file was created.
 .Sh FILES
-.Pa Input format:
+Input format:
 .Bd -literal
 1.2.3.4,1.2.4.4 name.my.domain,name,n.my.domain,n,1.2.3.4,1.2.4.4
 .Ed
 .Pp
-.Pa Output format for rsa1 keys:
+Output format for RSA1 keys:
 .Bd -literal
 host-or-namelist bits exponent modulus
 .Ed
 .Pp
-.Pa Output format for rsa, dsa and ecdsa keys:
+Output format for RSA, DSA, ECDSA, and Ed25519 keys:
 .Bd -literal
 host-or-namelist keytype base64-encoded-key
 .Ed
 .Pp
 Where
-.Pa keytype
+.Ar keytype
 is either
 .Dq ecdsa-sha2-nistp256 ,
 .Dq ecdsa-sha2-nistp384 ,
 .Dq ecdsa-sha2-nistp521 ,
+.Dq ssh-ed25519 ,
 .Dq ssh-dss
 or
 .Dq ssh-rsa .
 .Pp
 .Pa /etc/ssh/ssh_known_hosts
 .Sh EXAMPLES
-Print the
-.Pa rsa
-host key for machine
-.Pa hostname :
+Print the rsa host key for machine
+.Ar hostname :
 .Bd -literal
 $ ssh-keyscan hostname
 .Ed
@@ -153,7 +159,7 @@
 which have new or different keys from those in the sorted file
 .Pa ssh_known_hosts :
 .Bd -literal
-$ ssh-keyscan -t rsa,dsa,ecdsa -f ssh_hosts | \e
+$ ssh-keyscan -t rsa,dsa,ecdsa,ed25519 -f ssh_hosts | \e
 	sort -u - ssh_known_hosts | diff ssh_known_hosts -
 .Ed
 .Sh SEE ALSO
@@ -161,9 +167,9 @@
 .Xr sshd 8
 .Sh AUTHORS
 .An -nosplit
-.An David Mazieres Aq dm@lcs.mit.edu
+.An David Mazieres Aq Mt dm@lcs.mit.edu
 wrote the initial version, and
-.An Wayne Davison Aq wayned@users.sourceforge.net
+.An Wayne Davison Aq Mt wayned@users.sourceforge.net
 added support for protocol version 2.
 .Sh BUGS
 It generates "Connection closed by remote host" messages on the consoles