Work with netmail creation

app/helpers.php

@@ -0,0 +1,54 @@
+<?php
+
+/**
+ * Calculate CCITT-CRC16 checksum
+ */
+if (! function_exists('crc16')) {
+    function crc16($data)
+    {
+        $crc = 0x0000;
+        for ($i = 0; $i < strlen($data); $i++)
+        {
+            $x = (($crc >> 8) ^ ord($data[$i])) & 0xFF;
+            $x ^= $x >> 4;
+            $crc = (($crc << 8) ^ ($x << 12) ^ ($x << 5) ^ $x) & 0xFFFF;
+        }
+        return $crc;
+    }
+}
+
+/**
+ * Dump out data into a hex dump
+ */
+if (! function_exists('hex_dump')) {
+	function hex_dump($data,$newline="\n",$width=16)
+	{
+		$result = '';
+
+		$pad = '.'; # padding for non-visible characters
+		$to = $from = '';
+
+		for ($i=0; $i<=0xFF; $i++)
+		{
+			$from .= chr($i);
+			$to .= ($i >= 0x20 && $i <= 0x7E) ? chr($i) : $pad;
+		}
+
+		$hex = str_split(bin2hex($data),$width*2);
+		$chars = str_split(strtr($data,$from,$to),$width);
+
+		$offset = 0;
+		foreach ($hex as $i => $line)
+		{
+			$result .= sprintf('%08X: %-48s  [%s]%s',
+				$offset,
+				substr_replace(implode(' ',str_split($line,2)),' ',8*3,0),
+				$chars[$i],
+				$newline);
+
+			$offset += $width;
+		}
+
+		return $result;
+	}
+}