internal override DnsResourceData CreateInstance(DnsDatagram dns, int offsetInDns, int length)
{
if (length < ConstantPartLength + DnsDomainName.RootLength)
{
return(null);
}
DnsDomainName algorithm;
int algorithmLength;
if (!DnsDomainName.TryParse(dns, offsetInDns, length - ConstantPartLength, out algorithm, out algorithmLength))
{
return(null);
}
offsetInDns += algorithmLength;
length -= algorithmLength;
if (length < ConstantPartLength)
{
return(null);
}
UInt48 timeSigned = dns.ReadUInt48(offsetInDns + OffsetAfterAlgorithm.TimeSigned, Endianity.Big);
ushort fudge = dns.ReadUShort(offsetInDns + OffsetAfterAlgorithm.Fudge, Endianity.Big);
int messageAuthenticationCodeLength = dns.ReadUShort(offsetInDns + OffsetAfterAlgorithm.MessageAuthenticationCodeSize, Endianity.Big);
if (length < ConstantPartLength + messageAuthenticationCodeLength)
{
return(null);
}
DataSegment messageAuthenticationCode = dns.Subsegment(offsetInDns + OffsetAfterAlgorithm.MessageAuthenticationCode, messageAuthenticationCodeLength);
int totalReadAfterAlgorithm = OffsetAfterAlgorithm.MessageAuthenticationCode + messageAuthenticationCodeLength;
offsetInDns += totalReadAfterAlgorithm;
length -= totalReadAfterAlgorithm;
ushort originalId = dns.ReadUShort(offsetInDns + OffsetAfterMessageAuthenticationCode.OriginalId, Endianity.Big);
DnsResponseCode error = (DnsResponseCode)dns.ReadUShort(offsetInDns + OffsetAfterMessageAuthenticationCode.Error, Endianity.Big);
int otherLength = dns.ReadUShort(offsetInDns + OffsetAfterMessageAuthenticationCode.OtherLength, Endianity.Big);
if (length != OffsetAfterMessageAuthenticationCode.OtherData + otherLength)
{
return(null);
}
DataSegment other = dns.Subsegment(offsetInDns + OffsetAfterMessageAuthenticationCode.OtherData, otherLength);
return(new DnsResourceDataTransactionSignature(algorithm, timeSigned, fudge, messageAuthenticationCode, originalId, error, other));
}
internal override DnsResourceData CreateInstance(DnsDatagram dns, int offsetInDns, int length)
{
if (length < 17)
{
return((DnsResourceData)null);
}
DnsDomainName domainName;
int numBytesRead;
if (!DnsDomainName.TryParse(dns, offsetInDns, length - 16, out domainName, out numBytesRead))
{
return((DnsResourceData)null);
}
offsetInDns += numBytesRead;
length -= numBytesRead;
if (length < 16)
{
return((DnsResourceData)null);
}
UInt48 timeSigned = dns.ReadUInt48(offsetInDns, Endianity.Big);
ushort fudge = dns.ReadUShort(offsetInDns + 6, Endianity.Big);
int length1 = (int)dns.ReadUShort(offsetInDns + 8, Endianity.Big);
if (length < 16 + length1)
{
return((DnsResourceData)null);
}
DataSegment messageAuthenticationCode = dns.Subsegment(offsetInDns + 10, length1);
int num = 10 + length1;
offsetInDns += num;
length -= num;
ushort originalId = dns.ReadUShort(offsetInDns, Endianity.Big);
DnsResponseCode error = (DnsResponseCode)dns.ReadUShort(offsetInDns + 2, Endianity.Big);
int length2 = (int)dns.ReadUShort(offsetInDns + 4, Endianity.Big);
if (length != 6 + length2)
{
return((DnsResourceData)null);
}
DataSegment other = dns.Subsegment(offsetInDns + 6, length2);
return((DnsResourceData) new DnsResourceDataTransactionSignature(domainName, timeSigned, fudge, messageAuthenticationCode, originalId, error, other));
}