diff --git a/library/crc.c b/library/crc.c
new file mode 100644
index 0000000..9e21f25
--- /dev/null
+++ b/library/crc.c
@@ -0,0 +1,55 @@
+/*
+ *  CRC-16/ARC implementation, generated using pycrc v0.9.2, https://pycrc.org,
+ *  with further FI countermeasures added manually.
+ *
+ *  Used options: --model=crc-16 --algorithm=tbl --generate=c --std=C89 --table-idx-width 4
+ *
+ *  Copyright (C) 2006-2020, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_CRC_C)
+
+#include "mbedtls/crc.h"
+
+static const uint32_t crc_table[16] = {
+    0x0000, 0xcc01, 0xd801, 0x1400, 0xf001, 0x3c00, 0x2800, 0xe401,
+    0xa001, 0x6c00, 0x7800, 0xb401, 0x5000, 0x9c01, 0x8801, 0x4400
+};
+
+uint16_t mbedtls_crc_update( uint16_t crc, const void *data, size_t data_len )
+{
+    const unsigned char *d = (const unsigned char *)data;
+    unsigned int tbl_idx;
+
+    while ( data_len -- ) {
+        tbl_idx = crc ^ *d;
+        crc = crc_table[tbl_idx & 0x0f] ^ ( crc >> 4 );
+        tbl_idx = crc ^ ( *d >> 4 );
+        crc = crc_table[tbl_idx & 0x0f] ^ ( crc >> 4 );
+        d ++;
+    }
+    return crc;
+}
+
+#endif /* MBEDTLS_CRC_C */