* Stephane Bortzmeyer:
According to RFC 3597, the length is the length of the RDATA (resource
data). Does it include the length itself, like Florian assumes? I do
not think so, because of this example in the RFC:
If the RDATA is of zero length, the text representation contains only
the \# token and the single zero representing the length.
So, I believe I am right. The other examples in the RFC support my
claim.
You also have to comply with the requirement that SPF (type 99)
records use the same format as TXT records. A few quotes from
RFC 1035:
| 3.3. Standard RRs
| <domain-name> is a domain name represented as a series of labels, and
| terminated by a label with zero length. <character-string> is a single
| length octet followed by that number of characters. <character-string>
| is treated as binary information, and can be up to 256 characters in
| length (including the length octet).
| 3.3.14. TXT RDATA format
|
| +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| / TXT-DATA /
| +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|
| where:
|
| TXT-DATA One or more <character-string>s.