host: Add dcrypto definitions that can be used by fuzzing targets.

These definitions provide the necessary dcrypto functionality for
fuzzing pinweaver. They can be built out as needed to support
further fuzzing.

BRANCH=none
BUG=chromium:876582
TEST=make -j buildfuzztests &&
  ./build/host/cr50_fuzz/cr50_fuzz.exe (with the cr50_fuzz CL)

Change-Id: I36ce874efab5dbc59825d126f6079b7b6d0da9ef
Signed-off-by: Allen Webb <allenwebb@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1180573
Reviewed-by: Randall Spangler <rspangler@chromium.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/chip/host/dcrypto/app_cipher.c b/chip/host/dcrypto/app_cipher.c
new file mode 100644
index 0000000000..af6c2c4beb
--- /dev/null
+++ b/chip/host/dcrypto/app_cipher.c
@@ -0,0 +1,33 @@
+/* Copyright 2018 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "dcrypto.h"
+#include "util.h"
+
+void app_compute_hash(uint8_t *p_buf, size_t num_bytes,
+		      uint8_t *p_hash, size_t hash_len)
+{
+	uint8_t digest[SHA256_DIGEST_SIZE];
+
+	/*
+	 * Use the built in dcrypto engine to generate the sha1 hash of the
+	 * buffer.
+	 */
+	DCRYPTO_SHA256_hash((uint8_t *)p_buf, num_bytes, digest);
+
+	memcpy(p_hash, digest, MIN(hash_len, sizeof(digest)));
+
+	if (hash_len > sizeof(digest))
+		memset(p_hash + sizeof(digest), 0,
+		       hash_len - sizeof(digest));
+}
+
+int app_cipher(const void *salt_p, void *out_p, const void *in_p, size_t size)
+{
+	/* See README.md for while this is a passthrough. */
+	memcpy(out_p, in_p, size);
+	return 1;
+}
+