internal static bool TryReadTagAndLength(ReadOnlySequence <byte> buffer, out long length)
{
if (buffer.IsSingleSegment)
{
return(TryReadTagAndLength(buffer.First, out length));
}
length = 0;
if (!AsnReader.TryPeekTag(buffer.First.Span, out _, out int tagBytes))
{
return(false);
}
buffer = buffer.Slice(tagBytes);
if (!AsnReader.TryReadLength(buffer.First.Span, AsnEncodingRules.BER, out var asnLength, out var lengthBytes))
{
return(false);
}
if (!asnLength.HasValue)
{
return(false);
}
length = asnLength.Value;
length += lengthBytes;
length += tagBytes;
return(true);
}
private static bool TryReadTagAndLength(ReadOnlyMemory <byte> buffer, out long length)
{
length = 0;
if (!AsnReader.TryPeekTag(buffer.Span, out _, out int tagBytes))
{
return(false);
}
if (!AsnReader.TryReadLength(buffer.Span.Slice(tagBytes), AsnEncodingRules.BER, out var asnLength, out var lengthBytes))
{
return(false);
}
if (!asnLength.HasValue)
{
return(false);
}
length = asnLength.Value;
length += lengthBytes;
length += tagBytes;
return(true);
}