public static int GetTagLength(BerTag tag)
{
var number = tag.Number;
if (number < 0x1F)
{
return(1);
}
return(1 + GetMultiByteLongLength(number));
}
public static int GetHeaderLength(BerTag tag, int length)
{
int result = GetTagLength(tag);
if (length <= 0x7F || length == BerDefinitions.IndefiniteLength)
{
return(result + 1);
}
return(result + 1 + GetIntegerLength(length));
}
static int DecodeHeader(IBerInput input, BerTag expectedTag)
{
var tag = BerEncoding.DecodeTag(input);
if (tag != expectedTag)
{
throw new BerException(4001, String.Format("Expected tag {0}, found tag {1}", tag, expectedTag));
}
return(BerEncoding.DecodeLength(input));
}
// ====================================================================
//
// Decode functions
//
// ====================================================================
#region DecodeFunctions
public static BerTag DecodeTag(IBerInput input)
{
var tagByte = input.ReadByte();
var tag = new BerTag((byte)(tagByte & 0xE0), (uint)(tagByte & 0x1F));
if (tag.Number == 0x1F)
{
tag.Number = DecodeMultiByteInteger(input);
}
return(tag);
}
// ====================================================================
//
// Encode functions
// all return the number of bytes in the
// encoded result.
//
// ====================================================================
#region Encode Functions
public static int EncodeTag(IBerOutput output, BerTag tag)
{
var number = tag.Number;
var size = 1;
tag.Preamble &= 0xE0;
if (number < 0x1F)
{
output.WriteByte((byte)(tag.Preamble | (number & 0x1F)));
}
else
{
output.WriteByte((byte)(tag.Preamble | 0x1F));
size += EncodeMultiByteInteger(output, number);
}
return(size);
}
static void EncodeHeader(IBerOutput output, BerTag tag, int length)
{
BerEncoding.EncodeTag(output, tag);
BerEncoding.EncodeLength(output, length);
}
