bundle libtls

gmid (like all other daemons that want to do privsep crypto) has a
very close relationship with libtls and need to stay in sync with
it.

OpenBSD' libtls was recently changed to use OpenSSL' EC_KEY_METHOD
instead of the older ECDSA_METHOD, on the gmid side we have to do
the same otherwise failures happens at runtime.  In a similar manner,
privsep crypto is silently broken in the current libretls (next
version should fix it.)

The proper solution would be to complete the signer APIs so that
applications don't need to dive into the library' internals, but
that's a mid-term goal, for the immediate bundling the 'little'
libtls is the lesser evil.

The configure script has gained a new (undocumented for the time
being) flag `--with-libtls=bundled|system' to control which libtls
to use.  It defaults to `bundled' except for OpenBSD where it uses
the `system' one.  Note that OpenBSD versions before 7.3 (inclusive)
ought to use --with-libtls=bundled too since they still do ECDSA_METHOD.

1 files changed, 96 insertions, 0 deletions

diff --git a/compat/getentropy.c b/compat/getentropy.c
new file mode 100644
index 0000000..dc33884
--- /dev/null
+++ b/compat/getentropy.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 1996, David Mazieres <dm@uun.org>
+ * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
+ * Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
+ *
+ * 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.
+ */
+
+#include "../config.h"
+
+#ifndef SSH_RANDOM_DEV
+# define SSH_RANDOM_DEV "/dev/urandom"
+#endif /* SSH_RANDOM_DEV */
+
+#include <sys/types.h>
+#ifdef HAVE_SYS_RANDOM_H
+# include <sys/random.h>
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#ifdef WITH_OPENSSL
+#include <openssl/rand.h>
+#include <openssl/err.h>
+#endif
+
+#include "log.h"
+
+int _ssh_compat_getentropy(void *, size_t);
+
+static int
+seed_from_prngd(unsigned char *buf, size_t bytes)
+{
+	return -1;
+}
+
+int
+_ssh_compat_getentropy(void *s, size_t len)
+{
+#if defined(WITH_OPENSSL) && defined(OPENSSL_PRNG_ONLY)
+	if (RAND_bytes(s, len) <= 0)
+		fatal("Couldn't obtain random bytes (error 0x%lx)",
+		    (unsigned long)ERR_get_error());
+#else
+	int fd, save_errno;
+	ssize_t r;
+	size_t o = 0;
+
+#ifdef WITH_OPENSSL
+	if (RAND_bytes(s, len) == 1)
+		return 0;
+#endif
+#ifdef HAVE_GETENTROPY
+	if ((r = getentropy(s, len)) == 0)
+		return 0;
+#endif /* HAVE_GETENTROPY */
+#ifdef HAVE_GETRANDOM
+	if ((r = getrandom(s, len, 0)) > 0 && (size_t)r == len)
+		return 0;
+#endif /* HAVE_GETRANDOM */
+
+	if ((fd = open(SSH_RANDOM_DEV, O_RDONLY)) == -1) {
+		save_errno = errno;
+		/* Try egd/prngd before giving up. */
+		if (seed_from_prngd(s, len) == 0)
+			return 0;
+		fatal("Couldn't open %s: %s", SSH_RANDOM_DEV,
+		    strerror(save_errno));
+	}
+	while (o < len) {
+		r = read(fd, (u_char *)s + o, len - o);
+		if (r < 0) {
+			if (errno == EAGAIN || errno == EINTR ||
+			    errno == EWOULDBLOCK)
+				continue;
+			fatal("read %s: %s", SSH_RANDOM_DEV, strerror(errno));
+		}
+		o += r;
+	}
+	close(fd);
+#endif /* WITH_OPENSSL */
+	return 0;
+}