How does AS2 canonicalize text/plain?


How is a simple textfile (content-type: text/plain) canonicalized in mendelson AS2 for calculating the signatures-digest?

I have a problem with a partner where he is not able to verify (digest mismatch) a simple outbound message that has LF (0x0a) for line separators.
Content-encoding is binary - no problem appears if base64 is used.
Is is also working if CRLF (0x0d 0x0a) is used for line separators.

So I think it is about a different canonicalization.
Thanks for help!