Add libsecureboot

Used by loader and veriexec
Depends on libbearssl

Reviewed by:	emaste
Sponsored by:	Juniper Networks
Differential Revision:	D16335

1 files changed, 84 insertions, 0 deletions

diff --git a/lib/libsecureboot/vepcr.c b/lib/libsecureboot/vepcr.c
new file mode 100644
index 000000000000..0a3dc1fa12eb
--- /dev/null
+++ b/lib/libsecureboot/vepcr.c
@@ -0,0 +1,84 @@
+/*-
+ * Copyright (c) 2018, Juniper Networks, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "libsecureboot-priv.h"
+
+/*
+ * To support measured boot without putting a ton
+ * of extra code in the loader, we just maintain
+ * a hash of all the hashes we (attempt to) verify.
+ * The loader can export this for kernel or rc script
+ * to feed to a TPM pcr register - hence the name ve_pcr.
+ *
+ * NOTE: in the current standard the TPM pcr register size is for SHA1,
+ * the fact that we provide a SHA256 hash should not matter
+ * as long as we are consistent - it can be truncated or hashed
+ * before feeding to TPM.
+ */
+
+static const br_hash_class *pcr_md = NULL;
+static br_hash_compat_context pcr_ctx;
+static size_t pcr_hlen = 0;
+
+/**
+ * @brief initialize pcr context
+ *
+ * Real TPM registers only hold a SHA1 hash
+ * but we use SHA256
+ */
+void
+ve_pcr_init(void)
+{
+	pcr_hlen = br_sha256_SIZE;
+	pcr_md = &br_sha256_vtable;
+	pcr_md->init(&pcr_ctx.vtable);
+}
+
+/**
+ * @brief update pcr context
+ */
+void
+ve_pcr_update(unsigned char *data, size_t dlen)
+{
+	if (pcr_md)
+		pcr_md->update(&pcr_ctx.vtable, data, dlen);
+}
+
+/**
+ * @brief get pcr result
+ */
+ssize_t
+ve_pcr_get(unsigned char *buf, size_t sz)
+{
+	if (!pcr_md)
+		return (-1);
+	if (sz < pcr_hlen)
+		return (-1);
+	pcr_md->out(&pcr_ctx.vtable, buf);
+	return (pcr_hlen);
+}
+