From 0fa708acb2eb5222855e77cf401e282b2b9b6af3 Mon Sep 17 00:00:00 2001
From: merlokk <807634+merlokk@users.noreply.github.com>
Date: Fri, 9 Jul 2021 01:26:47 +0300
Subject: [PATCH] add crc32 check

---
 client/src/mifare/desfire_crypto.c | 6 ++++++
 client/src/mifare/desfire_crypto.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/client/src/mifare/desfire_crypto.c b/client/src/mifare/desfire_crypto.c
index 935083ab4..137eb8089 100644
--- a/client/src/mifare/desfire_crypto.c
+++ b/client/src/mifare/desfire_crypto.c
@@ -976,6 +976,12 @@ void desfire_crc32_append(uint8_t *data, const size_t len) {
     crc32_ex(data, len, data + len);
 }
 
+bool desfire_crc32_check(uint8_t *data, const size_t len, uint8_t *crc) {
+    uint8_t ccrc[4] = {0};
+    crc32_ex(data, len, ccrc);
+    return (memcmp(ccrc, crc, 4) == 0);
+}
+
 void iso14443a_crc_append(uint8_t *data, size_t len) {
     return compute_crc(CRC_14443_A, data, len, data + len, data + len + 1);
 }
diff --git a/client/src/mifare/desfire_crypto.h b/client/src/mifare/desfire_crypto.h
index 346a7e50c..8cdf76ab6 100644
--- a/client/src/mifare/desfire_crypto.h
+++ b/client/src/mifare/desfire_crypto.h
@@ -149,6 +149,7 @@ void mifare_kdf_an10922(const desfirekey_t key, const uint8_t *data, size_t len)
 
 void desfire_crc32(const uint8_t *data, const size_t len, uint8_t *crc);
 void desfire_crc32_append(uint8_t *data, const size_t len);
+bool desfire_crc32_check(uint8_t *data, const size_t len, uint8_t *crc);
 void iso14443a_crc_append(uint8_t *data, size_t len);
 void iso14443a_crc(uint8_t *data, size_t len, uint8_t *pbtCrc);
 #endif