BackUp

2025-06-11 02:53:23 +02:00 · 2020-10-06 15:59:53 +02:00
parent d601e9afb3
commit f5dffcec5b
5 changed files with 338 additions and 67 deletions
--- a/NFC/Crypto/CRC32.cs
+++ b/NFC/Crypto/CRC32.cs
@ -0,0 +1,44 @@
+using System;
+
+namespace NFC.Crypto
+{
+    public class CRC32
+    {
+        public byte[] Calculate(byte[] data)
+        {
+            UInt32 crc32 = 0xFFFFFFFF;
+
+            crc32 = Calculate(data, crc32);
+
+            return BitConverter.GetBytes(crc32);
+        }
+
+        public byte[] Calculate(byte[] cmd, byte[] data)
+        {
+            UInt32 crc32 = 0xFFFFFFFF;
+
+            crc32 = Calculate(cmd, crc32);
+            crc32 = Calculate(data, crc32);
+
+            return BitConverter.GetBytes(crc32);
+        }
+
+        public UInt32 Calculate(byte[] data, UInt32 crc32)
+        {
+            for (int i = 0; i < data.Length; i++)
+            {
+                crc32 ^= data[i];
+                for (int b = 0; b < 8; b++)
+                {
+                    bool b_Bit = (crc32 & 0x01) > 0;
+                    crc32 >>= 1;
+                    if (b_Bit)
+                    {
+                        crc32 ^= 0xEDB88320;
+                    }
+                }
+            }
+            return crc32;
+        }
+    }
+}