public static long GetTotalByteCount(Asn1Tag node)
{
if (node.Constructed)
{
return(Asn1.EncodeHeader(node).Length + node.Sum(subTag => GetTotalByteCount(subTag)));
}
else
{
return(Asn1.EncodeHeader(node).Length + node.Data.Length);
}
}
protected internal void ToShortText(ConsoleTable output, int indentLevel)
{
output.AddRow(
StartByte.ToString(),
(IndefiniteLength) ? "inf" : Asn1.GetTotalByteCount(this).ToString(),
Constructed ? "cons" : "prim",
Identifier.ToString(),
string.Concat(string.Empty.PadLeft(indentLevel * 2, ' '), ShortDescription),
DataText
);
if (Constructed)
{
foreach (Asn1Tag subTag in SubTags)
{
subTag.ToShortText(output, indentLevel + 1);
}
}
}
/// <summary>
/// Parse data in a (BitString) node if it's valid ASN.1 and add read nodes as sub nodes to this node.
/// </summary>
/// <param name="node">Node to read data from.</param>
/// <returns>True if valid ASN.1 was read, false if not.</returns>
private static bool ReadSubAsn1(Asn1Tag node, int dataOffset)
{
try
{
using (MemoryStream ms = new MemoryStream(node.Data, dataOffset, node.Data.Length - 1))
{
Asn1Tag subTag = Asn1.Decode(ms);
subTag.ToShortText(); // To validate, if it fails with exception, it's not added
node.AddSubTag(subTag);
return(true);
}
}
catch (Exception ex) // TODO: narrow this down
{
Console.WriteLine("Exception: " + ex.Message);
return(false);
}
}
/// <summary>
/// Read an ASN.1 tag identifier from a stream (as specified in X.690)
/// </summary>
/// <param name="stream">Stream to read from</param>
/// <param name="tagClass">Tag class of the tag</param>
/// <param name="constructed">Indicates if the tag is constructed = true (or primitive = false)</param>
/// <returns></returns>
private static int ReadIdentifier(Stream stream, out Asn1.Class tagClass, out bool constructed, out int fullIdentifier, out bool forceMultiByteIdentifier)
{
int identifier;
int b = stream.ReadByte();
if (b < 0) throw new IOException("Unexpected end of ASN.1 data while reading identifier.");
// 8 7 | 6 | 5 4 3 2 1
// Class |P/C| Tag number
tagClass = (Asn1.Class)(b >> 6);
constructed = (b & 0x20) != 0;
fullIdentifier = 0;
if ((b & 0x1f) != 0x1f)
{
// Single byte identifier
identifier = b & 0x1f;
fullIdentifier = b;
forceMultiByteIdentifier = false;
}
else
{
// Multi byte identifier
identifier = 0;
fullIdentifier |= b;
// juse to be sure we force encoding this to multiple bytes to maintain the structue as much as we can
forceMultiByteIdentifier = true;
do
{
b = stream.ReadByte();
if (b < 0) throw new IOException("Unexpected end of ASN.1 data while reading multi byte identifier.");
identifier <<= 7; // also happens first time, but that's ok, it's still 0
identifier |= b & 0x7F;
fullIdentifier <<= 8;
fullIdentifier |= b;
if (identifier == 0) throw new IOException("Invalid ASN.1 identifier (0 while reading constructed identifier).");
} while ((b & 0x80) != 0);
}
return identifier;
}
