Hi Duane ,
Here are some additional comments on the express profile
specs dated June 28, 2007. Overall I think these are considerably
improved over the initial drafts.
Secure-Addressing:
-
Line 69: “Extend the requirements of the WS-I …”
doesn’t sound right. Perhaps “Address additional grid
interoperability requirements not covered in WS-i…”
-
Line 86 “client to engage in secure
communication.” How about “client to engage in secure communication
and effectively use an OGSA web service”. This at least acknowledges
concerns raised by David Chadwick about providing the tokens needed to authZ
actions at the service.
-
Line 173: It should be WS-SecurityPolicy 1.2, not 1.5.
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Line282: Add to end of the paragraph – “The
INITIATOR may need the RECIPIENT’s token to supply a verifiable key used
for message-level encryption of an initial request message.
-
Section 4.3: If we’re specifying a ‘secure
endpoint reference’ then we should say something about how these EPR documents
are distributed. There are several possible attacks from modifying these
documents in transit (man-in-the-middle attacks, failing to sign and/or encrypt
the message correctly). One option is to provide for signing of these documents
by the service, in which case we should spec how they are signed. This is the
most scalable approach. One could also assume distribution via trusted server
over TLS/SSL, but that’s likely unacceptable in a lot of
environments.
Secure-Transport
-
Line 248, 252: You reference the ciphersuites in
WS-SecurityPolicy. This is a fine list of strong suites, but unfortunately doesn’t
include a cross-reference to the TLS/SSL standard ciphersuite identifiers. You
provide an example translation on Line 384. A simple mapping table would
likely help out people reading this spec who are familiar with the TSL/SSL
suite names.
-
Line 312: Providing to EPR document signing would help
address the issue you raise regarding EPRs coming from untrusted sources.
Secure-Soap
-
Line 285: It says “.. this Profile requires
encrypted communication”. Based on prior discussions, I had thought
it was agreed integrity protection was a MUST but confidentiality was optional?
-
Section 7: I still have a problem with the wording
here. Stating in C0701 that “UsernameToken credentials SHOULD NOT be used
for message authentication..”, and then having Section 7.2 explain how to
indicate they should be used for message level client authentication, seems contradictory.
C0701 also says username tokens “are not cryptographically verifiable.”.
Of course, if one uses password digest (with nonce & timestamp) one can get
cryptographically strong verification the sender knew the password and the token
wasn’t pasted in from some other message. Was your intent in C0701 to
warn people that username tokens should be used with caution since they: 1) don’t
provide a basis for ensuring overall message integrity; 2) the binding between
the token and message is weak? Perhaps just remove C0701 since it’s the only
numbered security consideration in the document and the requirements in Section
4.2 already ensure it can’t be used unless you’re using secure
transport.
Regards,
Blair Dillaway