internal Asn1Tag ReadTagAndLength(out int?contentsLength, out int bytesRead)
{
if (Asn1Tag.TryDecode(_data, out Asn1Tag tag, out int tagBytesRead) &&
TryReadLength(_data.Slice(tagBytesRead), RuleSet, out int?length, out int lengthBytesRead))
{
int allBytesRead = tagBytesRead + lengthBytesRead;
if (tag.IsConstructed)
{
// T-REC-X.690-201508 sec 9.1 (CER: Length forms) says constructed is always indefinite.
if (RuleSet == AsnEncodingRules.CER && length != null)
{
throw new CryptographicException(SR.Cryptography_Der_Invalid_Encoding);
}
}
else if (length == null)
{
// T-REC-X.690-201508 sec 8.1.3.2 says primitive encodings must use a definite form.
throw new CryptographicException(SR.Cryptography_Der_Invalid_Encoding);
}
bytesRead = allBytesRead;
contentsLength = length;
return(tag);
}
throw new CryptographicException(SR.Cryptography_Der_Invalid_Encoding);
}
/// <summary>
/// Read the encoded tag at the next data position, without advancing the reader.
/// </summary>
/// <returns>
/// The decoded <see cref="Asn1Tag"/> value.
/// </returns>
/// <exception cref="CryptographicException">
/// a tag could not be decoded at the reader's current position.
/// </exception>
public Asn1Tag PeekTag()
{
if (Asn1Tag.TryDecode(_data, out Asn1Tag tag, out int bytesRead))
{
return(tag);
}
throw new CryptographicException(SR.Cryptography_Der_Invalid_Encoding);
}
internal void Encode(AsnWriter writer)
{
bool wroteValue = false;
if (TeletexString != null)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.WriteCharacterString(UniversalTagNumber.T61String, TeletexString);
wroteValue = true;
}
if (PrintableString != null)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.WriteCharacterString(UniversalTagNumber.PrintableString, PrintableString);
wroteValue = true;
}
if (UniversalString.HasValue)
{
if (wroteValue)
{
throw new CryptographicException();
}
// Validator for tag constraint for UniversalString
{
if (!Asn1Tag.TryDecode(UniversalString.Value.Span, out Asn1Tag validateTag, out _) ||
!validateTag.HasSameClassAndValue(new Asn1Tag((UniversalTagNumber)28)))
{
throw new CryptographicException();
}
}
writer.WriteEncodedValue(UniversalString.Value.Span);
wroteValue = true;
}
if (Utf8String != null)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.WriteCharacterString(UniversalTagNumber.UTF8String, Utf8String);
wroteValue = true;
}
if (BmpString != null)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.WriteCharacterString(UniversalTagNumber.BMPString, BmpString);
wroteValue = true;
}
if (!wroteValue)
{
throw new CryptographicException();
}
}
public void Encode(AsnWriter writer)
{
bool wroteValue = false;
if (OtherName.HasValue)
{
if (wroteValue)
{
throw new CryptographicException();
}
OtherName.Value.Encode(writer, new Asn1Tag(TagClass.ContextSpecific, 0));
wroteValue = true;
}
if (Rfc822Name != null)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.WriteCharacterString(new Asn1Tag(TagClass.ContextSpecific, 1), UniversalTagNumber.IA5String, Rfc822Name);
wroteValue = true;
}
if (DnsName != null)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.WriteCharacterString(new Asn1Tag(TagClass.ContextSpecific, 2), UniversalTagNumber.IA5String, DnsName);
wroteValue = true;
}
if (X400Address.HasValue)
{
if (wroteValue)
{
throw new CryptographicException();
}
// Validator for tag constraint for X400Address
{
if (!Asn1Tag.TryDecode(X400Address.Value.Span, out Asn1Tag validateTag, out _) ||
!validateTag.HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 3)))
{
throw new CryptographicException();
}
}
writer.WriteEncodedValue(X400Address.Value.Span);
wroteValue = true;
}
if (DirectoryName.HasValue)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.PushSequence(new Asn1Tag(TagClass.ContextSpecific, 4));
writer.WriteEncodedValue(DirectoryName.Value.Span);
writer.PopSequence(new Asn1Tag(TagClass.ContextSpecific, 4));
wroteValue = true;
}
if (EdiPartyName.HasValue)
{
if (wroteValue)
{
throw new CryptographicException();
}
EdiPartyName.Value.Encode(writer, new Asn1Tag(TagClass.ContextSpecific, 5));
wroteValue = true;
}
if (Uri != null)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.WriteCharacterString(new Asn1Tag(TagClass.ContextSpecific, 6), UniversalTagNumber.IA5String, Uri);
wroteValue = true;
}
if (IPAddress.HasValue)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.WriteOctetString(new Asn1Tag(TagClass.ContextSpecific, 7), IPAddress.Value.Span);
wroteValue = true;
}
if (RegisteredId != null)
{
if (wroteValue)
{
throw new CryptographicException();
}
writer.WriteObjectIdentifier(new Asn1Tag(TagClass.ContextSpecific, 8), RegisteredId);
wroteValue = true;
}
if (!wroteValue)
{
throw new CryptographicException();
}
}