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/ssherr.h b/ssherr.h
new file mode 100644
index 0000000..6f771b4
--- /dev/null
+++ b/ssherr.h
@@ -0,0 +1,84 @@
+/*	$OpenBSD: ssherr.h,v 1.3 2015/01/30 01:13:33 djm Exp $	*/
+/*
+ * Copyright (c) 2011 Damien Miller
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _SSHERR_H
+#define _SSHERR_H
+
+/* XXX are these too granular? not granular enough? I can't decide - djm */
+
+/* Error codes */
+#define SSH_ERR_SUCCESS				0
+#define SSH_ERR_INTERNAL_ERROR			-1
+#define SSH_ERR_ALLOC_FAIL			-2
+#define SSH_ERR_MESSAGE_INCOMPLETE		-3
+#define SSH_ERR_INVALID_FORMAT			-4
+#define SSH_ERR_BIGNUM_IS_NEGATIVE		-5
+#define SSH_ERR_STRING_TOO_LARGE		-6
+#define SSH_ERR_BIGNUM_TOO_LARGE		-7
+#define SSH_ERR_ECPOINT_TOO_LARGE		-8
+#define SSH_ERR_NO_BUFFER_SPACE			-9
+#define SSH_ERR_INVALID_ARGUMENT		-10
+#define SSH_ERR_KEY_BITS_MISMATCH		-11
+#define SSH_ERR_EC_CURVE_INVALID		-12
+#define SSH_ERR_KEY_TYPE_MISMATCH		-13
+#define SSH_ERR_KEY_TYPE_UNKNOWN		-14 /* XXX UNSUPPORTED? */
+#define SSH_ERR_EC_CURVE_MISMATCH		-15
+#define SSH_ERR_EXPECTED_CERT			-16
+#define SSH_ERR_KEY_LACKS_CERTBLOB		-17
+#define SSH_ERR_KEY_CERT_UNKNOWN_TYPE		-18
+#define SSH_ERR_KEY_CERT_INVALID_SIGN_KEY	-19
+#define SSH_ERR_KEY_INVALID_EC_VALUE		-20
+#define SSH_ERR_SIGNATURE_INVALID		-21
+#define SSH_ERR_LIBCRYPTO_ERROR			-22
+#define SSH_ERR_UNEXPECTED_TRAILING_DATA	-23
+#define SSH_ERR_SYSTEM_ERROR			-24
+#define SSH_ERR_KEY_CERT_INVALID		-25
+#define SSH_ERR_AGENT_COMMUNICATION		-26
+#define SSH_ERR_AGENT_FAILURE			-27
+#define SSH_ERR_DH_GEX_OUT_OF_RANGE		-28
+#define SSH_ERR_DISCONNECTED			-29
+#define SSH_ERR_MAC_INVALID			-30
+#define SSH_ERR_NO_CIPHER_ALG_MATCH		-31
+#define SSH_ERR_NO_MAC_ALG_MATCH		-32
+#define SSH_ERR_NO_COMPRESS_ALG_MATCH		-33
+#define SSH_ERR_NO_KEX_ALG_MATCH		-34
+#define SSH_ERR_NO_HOSTKEY_ALG_MATCH		-35
+#define SSH_ERR_NO_HOSTKEY_LOADED		-36
+#define SSH_ERR_PROTOCOL_MISMATCH		-37
+#define SSH_ERR_NO_PROTOCOL_VERSION		-38
+#define SSH_ERR_NEED_REKEY			-39
+#define SSH_ERR_PASSPHRASE_TOO_SHORT		-40
+#define SSH_ERR_FILE_CHANGED			-41
+#define SSH_ERR_KEY_UNKNOWN_CIPHER		-42
+#define SSH_ERR_KEY_WRONG_PASSPHRASE		-43
+#define SSH_ERR_KEY_BAD_PERMISSIONS		-44
+#define SSH_ERR_KEY_CERT_MISMATCH		-45
+#define SSH_ERR_KEY_NOT_FOUND			-46
+#define SSH_ERR_AGENT_NOT_PRESENT		-47
+#define SSH_ERR_AGENT_NO_IDENTITIES		-48
+#define SSH_ERR_BUFFER_READ_ONLY		-49
+#define SSH_ERR_KRL_BAD_MAGIC			-50
+#define SSH_ERR_KEY_REVOKED			-51
+#define SSH_ERR_CONN_CLOSED			-52
+#define SSH_ERR_CONN_TIMEOUT			-53
+#define SSH_ERR_CONN_CORRUPT			-54
+#define SSH_ERR_PROTOCOL_ERROR			-55
+
+/* Translate a numeric error code to a human-readable error string */
+const char *ssh_err(int n);
+
+#endif /* _SSHERR_H */