Padding and record sizes in draft-thomson-http-encryption

Hi Martin, others,

I have some comments in regards to draft-thomson-http-encryption.

Firstly, each record currently includes between 1 and 256 bytes of padding,
while the default record size is set to 4096 bytes. This is in many cases
not
sufficient, for example in the pad-to-next-power-of-two case.

I've proposed a pull request to change the padding size to two bytes.
  https://github.com/martinthomson/http-encryption/pull/7

The draft defines a streaming model having a sender-configurable record
size.
What is the motivation for allowing this by default? TLS defines 16KB
records
and only allows negotiation of this value per an extension.

Of course, introducing a fixed record size would violate the requirement
set by
draft-ietf-webpush-encryption of only allowing a single record, for any
message
that is larger than said size. A reasonably clean way of addressing this
would
be to separate the Content-Encoding values: aesgcm128 vs.
aes128gcm-streaming.

As a slight meta question, what are the expected users of the streaming
model?

Thanks,
Peter