From: Bernard Blackham <dagobah@ucc.asn.au>
Date: Wed, 23 Jun 2004 18:50:36 +0000 (+0000)
Subject: For generating CRCs
X-Git-Tag: ROMW~7
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=9203e74dcb42e84ba084914724b48cfac402c9b5;p=uccvend-snackrom.git

For generating CRCs
---

diff --git a/ROM2/crctest.c b/ROM2/crctest.c
new file mode 100644
index 0000000..bf48c89
--- /dev/null
+++ b/ROM2/crctest.c
@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <stdlib.h>
+typedef unsigned short u16;
+typedef unsigned char bool;
+#include "crctab.h"
+
+unsigned short
+docrc (unsigned char *p, int len, bool pad, unsigned short crcstart)
+{
+  int len2 = len;
+  unsigned short crc = crcstart;
+
+  while (len-- > 0)
+    crc = (crc << 8) ^ crctab[(crc >> 8) ^ *p++];
+  if (pad && len2 < 128) {
+    len = 128-len;
+    while (len-- > 0)
+      crc = (crc << 8) ^ crctab[(crc >> 8) ^ 0x1a];
+  }
+
+  return crc;
+}
+
+int main(int argc, char** argv) {
+	unsigned short crc;
+	unsigned short msgid;
+	char *password, *message;
+	if (argc != 4) {
+		fprintf(stderr, "Usage: %s <id> <password> <message>\n", argv[0]);
+		return 1;
+	}
+	msgid = strtol(argv[1], NULL, 16);
+	password = argv[2];
+	message = argv[3];
+	crc = docrc(((char*)&msgid)+1, 1, 0, 0);
+	crc = docrc(((char*)&msgid), 1, 0, crc);
+	crc = docrc(password, strlen(password), 0, crc);
+	crc = docrc(message, strlen(message), 0, crc);
+	printf("CRC is 0x%x\n", crc);
+	return 0;
+}