// Fetch out BER-encoded data until EOF or error
protected BerDecoderResult DecodeTlv(Stream asnStream, out TlvObject tlvObj, ref long offset, byte level, byte maxLevel)
{
BerDecoderResult procResult = BerDecoderResult.Finished;
tlvObj = null;
byte[] tlvBuffer = new byte[32];
byte tlvBuffer_Length = 0;
int octet;
int tlvTag = 0;
int tlvTag_Length = 0;
// Decode the TLV tag
while (tlvTag_Length == 0)
{
// Get the next byte from the input stream
octet = asnStream.ReadByte();
if (octet == -1)
{
return BerDecoderResult.EOF;
}
// Skip the fillers between billing records (TLV with level == 0)
if ((level == 0) && ((octet == 0xFF) || (octet == 0)))
{
offset++;
continue;
}
tlvBuffer[tlvBuffer_Length++] = (byte)octet;
tlvTag_Length = FetchTlvTag(tlvBuffer, tlvBuffer_Length, ref tlvTag);
switch (tlvTag_Length)
{
case -1:
return BerDecoderResult.Failed;
case 0:
continue; // More data expected
}
}
long tlvOffset = offset;
offset += tlvTag_Length;
bool _constructed = ((tlvBuffer[0] & 0x20) == 0x20);
int tlvLength = 0;
int tlvLength_Length = 0;
// Decode the TLV length
while (tlvLength_Length == 0)
{
// Get the next byte from the input stream
octet = asnStream.ReadByte();
if (octet == -1)
{
return BerDecoderResult.EOF;
}
tlvBuffer[tlvBuffer_Length++] = (byte)octet;
tlvLength_Length = FetchTlvLength(_constructed, tlvBuffer, tlvTag_Length, tlvBuffer_Length - tlvTag_Length, ref tlvLength);
switch (tlvLength_Length)
{
case -1:
return BerDecoderResult.Failed;
case 0:
continue; // More data expected
}
}
offset += tlvLength_Length;
tlvObj = new TlvObject(tlvTag >> 2, (AsnTagClass)(tlvBuffer[0] & 0xC0), _constructed, tlvOffset);
if (tlvLength > 0)
{
if (_constructed)
{
if (level < maxLevel)
{
long _vLength = offset + tlvLength;
BerDecoderResult _pr;
while (offset < _vLength)
{
TlvObject _childObj;
_pr = this.DecodeTlv(asnStream, out _childObj, ref offset, (byte)(level + 1), maxLevel);
if (_pr != BerDecoderResult.Finished)
{
break;
}
tlvObj.AddTlv(_childObj);
}
}
else
{
// Stop processing for TLV with level > maxLevel, and skip content.
offset += tlvLength;
asnStream.Seek(tlvLength, SeekOrigin.Current);
}
}
else
{
int _readOffset = tlvObj.ReadValue(asnStream, tlvLength);
offset += _readOffset;
if (_readOffset != tlvLength)
{
return BerDecoderResult.Failed;
}
}
}
return procResult;
}
// Fetch out BER-encoded data until EOF or error
protected BerDecoderResult DecodeTlv(Stream asnStream, out TlvObject tlvObj, ref long offset, byte level, byte maxLevel)
{
BerDecoderResult procResult = BerDecoderResult.Finished;
tlvObj = null;
byte[] tlvBuffer = new byte[32];
byte tlvBuffer_Length = 0;
int octet;
int tlvTag = 0;
int tlvTag_Length = 0;
// Decode the TLV tag
while (tlvTag_Length == 0)
{
// Get the next byte from the input stream
octet = asnStream.ReadByte();
if (octet == -1)
{
return(BerDecoderResult.EOF);
}
// Skip the fillers between billing records (TLV with level == 0)
if ((level == 0) && ((octet == 0xFF) || (octet == 0)))
{
offset++;
continue;
}
tlvBuffer[tlvBuffer_Length++] = (byte)octet;
tlvTag_Length = FetchTlvTag(tlvBuffer, tlvBuffer_Length, ref tlvTag);
switch (tlvTag_Length)
{
case -1:
return(BerDecoderResult.Failed);
case 0:
continue; // More data expected
}
}
long tlvOffset = offset;
offset += tlvTag_Length;
bool _constructed = ((tlvBuffer[0] & 0x20) == 0x20);
int tlvLength = 0;
int tlvLength_Length = 0;
// Decode the TLV length
while (tlvLength_Length == 0)
{
// Get the next byte from the input stream
octet = asnStream.ReadByte();
if (octet == -1)
{
return(BerDecoderResult.EOF);
}
tlvBuffer[tlvBuffer_Length++] = (byte)octet;
tlvLength_Length = FetchTlvLength(_constructed, tlvBuffer, tlvTag_Length, tlvBuffer_Length - tlvTag_Length, ref tlvLength);
switch (tlvLength_Length)
{
case -1:
return(BerDecoderResult.Failed);
case 0:
continue; // More data expected
}
}
offset += tlvLength_Length;
tlvObj = new TlvObject(tlvTag >> 2, (AsnTagClass)(tlvBuffer[0] & 0xC0), _constructed, tlvOffset);
if (tlvLength > 0)
{
if (_constructed)
{
if (level < maxLevel)
{
long _vLength = offset + tlvLength;
BerDecoderResult _pr;
while (offset < _vLength)
{
TlvObject _childObj;
_pr = this.DecodeTlv(asnStream, out _childObj, ref offset, (byte)(level + 1), maxLevel);
if (_pr != BerDecoderResult.Finished)
{
break;
}
tlvObj.AddTlv(_childObj);
}
}
else
{
// Stop processing for TLV with level > maxLevel, and skip content.
offset += tlvLength;
asnStream.Seek(tlvLength, SeekOrigin.Current);
}
}
else
{
int _readOffset = tlvObj.ReadValue(asnStream, tlvLength);
offset += _readOffset;
if (_readOffset != tlvLength)
{
return(BerDecoderResult.Failed);
}
}
}
return(procResult);
}
