1 files changed, 63 insertions, 0 deletions
diff --git a/common/mock/fpsensor_crypto_mock.c b/common/mock/fpsensor_crypto_mock.c
new file mode 100644
index 0000000000..f2cc425c8f
--- /dev/null
+++ b/common/mock/fpsensor_crypto_mock.c
@@ -0,0 +1,63 @@
+/* Copyright 2022 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/**
+ * @file fpsensor_crypto_mock.c
+ * @brief Mock fpsensor_crypto library
+ */
+#include "sha256.h"
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include "assert.h"
+#include "compile_time_macros.h"
+#include "console.h"
+#include "ec_commands.h"
+#include "fpsensor_private.h"
+#include "mock/fpsensor_crypto_mock.h"
+
+#ifndef TEST_BUILD
+#error "Mocks should only be in the test build."
+#endif
+
+struct mock_ctrl_fpsensor_crypto mock_ctrl_fpsensor_crypto =
+	MOCK_CTRL_DEFAULT_FPSENSOR_CRYPTO;
+
+#define MESSAGE_ZERO_IDX 0
+#define MESSAGE_FF_IDX 1
+typedef uint8_t key_message_pair[FP_POSITIVE_MATCH_SECRET_BYTES];
+
+key_message_pair fake_fpsensor_crypto[] = {
+	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+	{ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }
+};
+
+BUILD_ASSERT(sizeof(key_message_pair) == FP_POSITIVE_MATCH_SECRET_BYTES);
+
+/* Mock compute_hmac_sha256 for unit or fuzz tests. */
+void compute_hmac_sha256(uint8_t *output, const uint8_t *key, const int key_len,
+			 const uint8_t *message, const int message_len)
+{
+	switch (mock_ctrl_fpsensor_crypto.output_type) {
+	case MOCK_CTRL_FPSENSOR_CRYPTO_SHA256_TYPE_REAL:
+		hmac_SHA256(output, key, key_len, message, message_len);
+		break;
+	case MOCK_CTRL_FPSENSOR_CRYPTO_SHA256_TYPE_ZEROS:
+		memcpy(output, fake_fpsensor_crypto[MESSAGE_ZERO_IDX],
+		       FP_POSITIVE_MATCH_SECRET_BYTES);
+		break;
+	case MOCK_CTRL_FPSENSOR_CRYPTO_SHA256_TYPE_FF:
+		memcpy(output, fake_fpsensor_crypto[MESSAGE_FF_IDX],
+		       FP_POSITIVE_MATCH_SECRET_BYTES);
+		break;
+	default:
+		assert(0);
+		break;
+	};
+}