Replace the CRC16-CCITT implementation with one generated by pycrc to be MIT compliant.

Checksums/ccitt.c

@@ -0,0 +1,53 @@
+/**
+ * \file ccitt.c
+ * Functions and types for CRC checks.
+ *
+ * Generated on Sun Oct 30 02:18:53 2016,
+ * by pycrc v0.9, https://pycrc.org
+ * using the configuration:
+ *    Width         = 16
+ *    Poly          = 0x1021
+ *    Xor_In        = 0xffff
+ *    ReflectIn     = False
+ *    Xor_Out       = 0x0000
+ *    ReflectOut    = False
+ *    Algorithm     = bit-by-bit-fast
+ *****************************************************************************/
+#include "ccitt.h"     /* include the header file generated with pycrc */
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+/**
+ * Update the crc value with new data.
+ *
+ * \param crc      The current crc value.
+ * \param data     Pointer to a buffer of \a data_len bytes.
+ * \param data_len Number of bytes in the \a data buffer.
+ * \return         The updated crc value.
+ *****************************************************************************/
+crc_t crc_update(crc_t crc, const void *data, size_t data_len)
+{
+    const unsigned char *d = (const unsigned char *)data;
+    unsigned int i;
+    bool bit;
+    unsigned char c;
+
+    while (data_len--) {
+        c = *d++;
+        for (i = 0x80; i > 0; i >>= 1) {
+            bit = crc & 0x8000;
+            if (c & i) {
+                bit = !bit;
+            }
+            crc <<= 1;
+            if (bit) {
+                crc ^= 0x1021;
+            }
+        }
+        crc &= 0xffff;
+    }
+    return crc & 0xffff;
+}
+
+

Checksums/ccitt.cs

@@ -0,0 +1,55 @@
+// C# port of the ccitt.c/ccitt.h files in this directory.
+// Original files generated by pycrc v0.9, https://pycrc.org
+
+namespace Checksums {
+	public static class Ccitt {
+		/**
+		 * Calculate the initial crc value.
+		 *
+		 * \return     The initial crc value.
+		 *****************************************************************************/
+		public static ushort Init() {
+			return 0xffff;
+		}
+
+		/**
+		 * Update the crc value with new data.
+		 *
+		 * \param crc      The current crc value.
+		 * \param data     Pointer to a buffer of \a data_len bytes.
+		 * \param data_len Number of bytes in the \a data buffer.
+		 * \return         The updated crc value.
+		 *****************************************************************************/
+		public static ushort Update( ushort crc, byte[] data, long data_len ) {
+			uint i;
+			bool bit;
+			byte c;
+
+			for ( long idx = 0; idx < data_len;  ++idx ) {
+				c = data[idx];
+				for ( i = 0x80; i > 0; i >>= 1 ) {
+					bit = ( crc & 0x8000 ) != 0;
+					if ( ( c & i ) != 0 ) {
+						bit = !bit;
+					}
+					crc <<= 1;
+					if ( bit ) {
+						crc ^= 0x1021;
+					}
+				}
+				crc &= 0xffff;
+			}
+			return (ushort)( crc & 0xffff );
+		}
+
+		/**
+		 * Calculate the final crc value.
+		 *
+		 * \param crc  The current crc value.
+		 * \return     The final crc value.
+		 *****************************************************************************/
+		public static ushort Finalize( ushort crc ) {
+			return (ushort)( crc ^ 0x0000 );
+		}
+	}
+}

Checksums/ccitt.h

@@ -0,0 +1,82 @@
+/**
+ * \file ccitt.h
+ * Functions and types for CRC checks.
+ *
+ * Generated on Sun Oct 30 02:18:48 2016,
+ * by pycrc v0.9, https://pycrc.org
+ * using the configuration:
+ *    Width         = 16
+ *    Poly          = 0x1021
+ *    Xor_In        = 0xffff
+ *    ReflectIn     = False
+ *    Xor_Out       = 0x0000
+ *    ReflectOut    = False
+ *    Algorithm     = bit-by-bit-fast
+ *****************************************************************************/
+#ifndef __CCITT_H__
+#define __CCITT_H__
+
+#include <stdlib.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/**
+ * The definition of the used algorithm.
+ *
+ * This is not used anywhere in the generated code, but it may be used by the
+ * application code to call algoritm-specific code, is desired.
+ *****************************************************************************/
+#define CRC_ALGO_BIT_BY_BIT_FAST 1
+
+
+/**
+ * The type of the CRC values.
+ *
+ * This type must be big enough to contain at least 16 bits.
+ *****************************************************************************/
+typedef uint_fast16_t crc_t;
+
+
+/**
+ * Calculate the initial crc value.
+ *
+ * \return     The initial crc value.
+ *****************************************************************************/
+static inline crc_t crc_init(void)
+{
+    return 0xffff;
+}
+
+
+/**
+ * Update the crc value with new data.
+ *
+ * \param crc      The current crc value.
+ * \param data     Pointer to a buffer of \a data_len bytes.
+ * \param data_len Number of bytes in the \a data buffer.
+ * \return         The updated crc value.
+ *****************************************************************************/
+crc_t crc_update(crc_t crc, const void *data, size_t data_len);
+
+
+/**
+ * Calculate the final crc value.
+ *
+ * \param crc  The current crc value.
+ * \return     The final crc value.
+ *****************************************************************************/
+static inline crc_t crc_finalize(crc_t crc)
+{
+    return crc ^ 0x0000;
+}
+
+
+#ifdef __cplusplus
+}           /* closing brace for extern "C" */
+#endif
+
+#endif      /* __CCITT_H__ */