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/dns.h b/dns.h
index 90cfd7b..815f073 100644
--- a/dns.h
+++ b/dns.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: dns.h,v 1.11 2010/02/26 20:29:54 djm Exp $ */
+/* $OpenBSD: dns.h,v 1.14 2015/01/15 09:40:00 djm Exp $ */
 
 /*
  * Copyright (c) 2003 Wesley Griffin. All rights reserved.
@@ -29,14 +29,18 @@
 #define DNS_H
 
 enum sshfp_types {
-	SSHFP_KEY_RESERVED,
-	SSHFP_KEY_RSA,
-	SSHFP_KEY_DSA
+	SSHFP_KEY_RESERVED = 0,
+	SSHFP_KEY_RSA = 1,
+	SSHFP_KEY_DSA = 2,
+	SSHFP_KEY_ECDSA = 3,
+	SSHFP_KEY_ED25519 = 4 
 };
 
 enum sshfp_hashes {
-	SSHFP_HASH_RESERVED,
-	SSHFP_HASH_SHA1
+	SSHFP_HASH_RESERVED = 0,
+	SSHFP_HASH_SHA1 = 1,
+	SSHFP_HASH_SHA256 = 2,
+	SSHFP_HASH_MAX = 3
 };
 
 #define DNS_RDATACLASS_IN	1
@@ -46,7 +50,8 @@
 #define DNS_VERIFY_MATCH	0x00000002
 #define DNS_VERIFY_SECURE	0x00000004
 
-int	verify_host_key_dns(const char *, struct sockaddr *, Key *, int *);
-int	export_dns_rr(const char *, Key *, FILE *, int);
+int	verify_host_key_dns(const char *, struct sockaddr *,
+    struct sshkey *, int *);
+int	export_dns_rr(const char *, struct sshkey *, FILE *, int);
 
 #endif /* DNS_H */