// Implements major type 6 encoding per https://tools.ietf.org/html/rfc7049#section-2.1
/// <summary>
/// Assign a semantic tag (major type 6) to the next data item.
/// </summary>
/// <param name="tag">The value to write.</param>
/// <exception cref="InvalidOperationException">
/// Writing a new value exceeds the definite length of the parent data item. -or-
/// The major type of the encoded value is not permitted in the parent data item. -or-
/// The written data is not accepted under the current conformance level.
/// </exception>
public void WriteTag(CborTag tag)
{
if (!CborConformanceLevelHelpers.AllowsTags(ConformanceLevel))
{
throw new InvalidOperationException(SR.Format(SR.Cbor_ConformanceLevel_TagsNotSupported, ConformanceLevel));
}
WriteUnsignedInteger(CborMajorType.Tag, (ulong)tag);
_isTagContext = true;
}
public void WriteTag(CborTag tag)
{
if (!CborConformanceLevelHelpers.AllowsTags(ConformanceLevel))
{
throw new InvalidOperationException("Tagged items are not permitted under the current conformance level.");
}
WriteUnsignedInteger(CborMajorType.Tag, (ulong)tag);
_isTagContext = true;
}
public void WriteStartArray()
{
if (!ConvertIndefiniteLengthEncodings && CborConformanceLevelHelpers.RequiresDefiniteLengthItems(ConformanceLevel))
{
throw new InvalidOperationException(SR.Format(SR.Cbor_ConformanceLevel_IndefiniteLengthItemsNotSupported, ConformanceLevel));
}
EnsureWriteCapacity(1);
WriteInitialByte(new CborInitialByte(CborMajorType.Array, CborAdditionalInfo.IndefiniteLength));
PushDataItem(CborMajorType.Array, definiteLength: null);
}
public CborTag ReadTag()
{
CborTag tag = PeekTagCore(out int additionalBytes);
if (_isConformanceLevelCheckEnabled && !CborConformanceLevelHelpers.AllowsTags(ConformanceLevel))
{
throw new FormatException("Tagged items are not permitted under the current conformance level.");
}
AdvanceBuffer(1 + additionalBytes);
_isTagContext = true;
return(tag);
}
public void ReadTag(CborTag expectedTag)
{
CborTag tag = PeekTagCore(out int additionalBytes);
if (_isConformanceLevelCheckEnabled && !CborConformanceLevelHelpers.AllowsTags(ConformanceLevel))
{
throw new FormatException("Tagged items are not permitted under the current conformance level.");
}
if (expectedTag != tag)
{
throw new InvalidOperationException("CBOR tag mismatch.");
}
AdvanceBuffer(1 + additionalBytes);
_isTagContext = true;
}
/// <summary>
/// Writes a simple value encoding (major type 7).
/// </summary>
/// <param name="value">The value to write.</param>
/// <exception cref="ArgumentOutOfRangeException">
/// The <paramref name="value"/> parameter is in the invalid 24-31 range.
/// </exception>
/// <exception cref="InvalidOperationException">
/// Writing a new value exceeds the definite length of the parent data item. -or-
/// The major type of the encoded value is not permitted in the parent data item. -or-
/// The written data is not accepted under the current conformance level
/// </exception>
public void WriteSimpleValue(CborSimpleValue value)
{
if (value < (CborSimpleValue)CborAdditionalInfo.Additional8BitData)
{
EnsureWriteCapacity(1);
WriteInitialByte(new CborInitialByte(CborMajorType.Simple, (CborAdditionalInfo)value));
}
else if (value <= (CborSimpleValue)CborAdditionalInfo.IndefiniteLength &&
CborConformanceLevelHelpers.RequireCanonicalSimpleValueEncodings(ConformanceLevel))
{
throw new ArgumentOutOfRangeException(SR.Format(SR.Cbor_ConformanceLevel_InvalidSimpleValueEncoding, ConformanceLevel));
}
else
{
EnsureWriteCapacity(2);
WriteInitialByte(new CborInitialByte(CborMajorType.Simple, CborAdditionalInfo.Additional8BitData));
_buffer[_offset++] = (byte)value;
}
AdvanceDataItemCounters();
}
// Unsigned integer decoding https://tools.ietf.org/html/rfc7049#section-2.1
private ulong DecodeUnsignedInteger(CborInitialByte header, ReadOnlySpan <byte> data, out int bytesRead)
{
ulong result;
switch (header.AdditionalInfo)
{
case CborAdditionalInfo x when(x < CborAdditionalInfo.Additional8BitData):
bytesRead = 1;
return((ulong)x);
case CborAdditionalInfo.Additional8BitData:
EnsureReadCapacity(data, 1 + sizeof(byte));
result = data[1];
if (result < (int)CborAdditionalInfo.Additional8BitData)
{
ValidateIsNonStandardIntegerRepresentationSupported();
}
bytesRead = 1 + sizeof(byte);
return(result);
case CborAdditionalInfo.Additional16BitData:
EnsureReadCapacity(data, 1 + sizeof(ushort));
result = BinaryPrimitives.ReadUInt16BigEndian(data.Slice(1));
if (result <= byte.MaxValue)
{
ValidateIsNonStandardIntegerRepresentationSupported();
}
bytesRead = 1 + sizeof(ushort);
return(result);
case CborAdditionalInfo.Additional32BitData:
EnsureReadCapacity(data, 1 + sizeof(uint));
result = BinaryPrimitives.ReadUInt32BigEndian(data.Slice(1));
if (result <= ushort.MaxValue)
{
ValidateIsNonStandardIntegerRepresentationSupported();
}
bytesRead = 1 + sizeof(uint);
return(result);
case CborAdditionalInfo.Additional64BitData:
EnsureReadCapacity(data, 1 + sizeof(ulong));
result = BinaryPrimitives.ReadUInt64BigEndian(data.Slice(1));
if (result <= uint.MaxValue)
{
ValidateIsNonStandardIntegerRepresentationSupported();
}
bytesRead = 1 + sizeof(ulong);
return(result);
default:
throw new FormatException(SR.Cbor_Reader_InvalidCbor_InvalidIntegerEncoding);
}
void ValidateIsNonStandardIntegerRepresentationSupported()
{
if (_isConformanceLevelCheckEnabled && CborConformanceLevelHelpers.RequiresCanonicalIntegerRepresentation(ConformanceLevel))
{
throw new FormatException(SR.Format(SR.Cbor_ConformanceLevel_NonCanonicalIntegerRepresentation, ConformanceLevel));
}
}
}
// Unsigned integer decoding https://tools.ietf.org/html/rfc7049#section-2.1
private ulong ReadUnsignedInteger(ReadOnlySpan <byte> buffer, CborInitialByte header, out int additionalBytes)
{
ulong result;
switch (header.AdditionalInfo)
{
case CborAdditionalInfo x when(x < CborAdditionalInfo.Additional8BitData):
additionalBytes = 0;
return((ulong)x);
case CborAdditionalInfo.Additional8BitData:
EnsureBuffer(buffer, 2);
result = buffer[1];
if (result < (int)CborAdditionalInfo.Additional8BitData)
{
ValidateIsNonStandardIntegerRepresentationSupported();
}
additionalBytes = 1;
return(result);
case CborAdditionalInfo.Additional16BitData:
EnsureBuffer(buffer, 3);
result = BinaryPrimitives.ReadUInt16BigEndian(buffer.Slice(1));
if (result <= byte.MaxValue)
{
ValidateIsNonStandardIntegerRepresentationSupported();
}
additionalBytes = 2;
return(result);
case CborAdditionalInfo.Additional32BitData:
EnsureBuffer(buffer, 5);
result = BinaryPrimitives.ReadUInt32BigEndian(buffer.Slice(1));
if (result <= ushort.MaxValue)
{
ValidateIsNonStandardIntegerRepresentationSupported();
}
additionalBytes = 4;
return(result);
case CborAdditionalInfo.Additional64BitData:
EnsureBuffer(buffer, 9);
result = BinaryPrimitives.ReadUInt64BigEndian(buffer.Slice(1));
if (result <= uint.MaxValue)
{
ValidateIsNonStandardIntegerRepresentationSupported();
}
additionalBytes = 8;
return(result);
default:
throw new FormatException("initial byte contains invalid integer encoding data.");
}
void ValidateIsNonStandardIntegerRepresentationSupported()
{
if (_isConformanceLevelCheckEnabled && CborConformanceLevelHelpers.RequiresMinimalIntegerRepresentation(ConformanceLevel))
{
throw new FormatException("Non-minimal integer representations are not permitted under the current conformance level.");
}
}
}