RE: FW: DISCUSS: draft-ietf-ipcdn-bpiplus-mib-14
"Eduardo Cardona" <[email protected]>
| Newsgroups | gmane.ietf.ipcdn |
|---|---|
| Message-ID | <[email protected]> |
All,
I wrote:
"I can't disclosure current spec work around DOCSIS protocols in IPCDN
who includes
persons probably not under CableLabs NDAs.
Perhaps a reference to section 7.7 of BPI+ specification ... "
I would like to withdraw this part of my response, it was out of line.
The valid question was asked by Russ (and Bert) as part of the open IETF
process and a response should be provided in full disclosure to all the
IETF participants.
Thanks
Eduardo
-----Original Message-----
From: Eduardo Cardona
Sent: Thursday, September 23, 2004 10:34 AM
To: Wijnen, Bert (Bert); Ipcdn (E-mail)
Subject: RE: [ipcdn] FW: DISCUSS: draft-ietf-ipcdn-bpiplus-mib-14
Bert, I am not sure if this is just perception from the parser output:
Below is a similar public key pair that indicates the offsets line by
line
Ofsset 135 (zero based) indicates the start of the public exponent (5
bytes)
Offset 140 indicates the offset of byte 141
Here is a 140 octets PKCS#1 public key pair
Off
0 30 81 89
3 02 81 81
6 00 cf 32 d2 0b 31 d5 47 f9 73 98 8a 83 62 e1 fb
22 dc e6 3b 0b 4b b8 d6 3b 35 31 5d dc 7a 72 89 fe
38 e9 18 20 c7 83 7b 76 d7 75 36 91 72 f6 17 8f 5a
54 59 68 28 87 0d 9b 25 88 52 7b cb a2 52 10 26 89
70 69 4f 0d d1 d9 2d 71 aa 03 35 e2 81 5d b0 31 8b
86 4c 3d e9 0a df b4 8c e4 99 7f d1 47 86 5b 9e 3d
102 07 c3 a8 58 f3 2f f2 d3 09 a6 e3 e5 4c 53 23 44
118 46 6c 6b 03 ae 90 76 38 60 de 23 02 f9 c0 3b e4
134 ed
135 02 03 01 00 01
140
Bytes size = 3 + 3 + 129 + 5 = 140
And the output from for the equivalent binary file
from openssl asn1parse command:
0:d=0 hl=3 l= 137 cons: SEQUENCE
3:d=1 hl=3 l= 129 prim: INTEGER
:CF32D20B31D547F973988A8362E1FBDC
E63B0B4BB8D63B35315DDC7A7289FEE9
1820C7837B76D775369172F6178F5A59
6828870D9B2588527BCBA25210268969
4F0DD1D92D71AA0335E2815DB0318B4C
3DE90ADFB48CE4997FD147865B9E3D07
C3A858F32FF2D309A6E3E54C53234446
6C6B03AE90763860DE2302F9C03BE4ED
135:d=1 hl=2 l= 3 prim: INTEGER :010001
>
> I do not believe that a five (or even ten) specific sizes can be
> chosen that accommodate all valid RSA public keys.
DOCSIS uses a subset of moduli values that matches the sizes described
by the MIB object After the explanations above, is this still an issue?
> Can we get an strong
> integrity algorithm specified? If not, the last few paragraphs of
> of the Security Considerations need to be made much more forceful.
I can't disclosure current spec work around DOCSIS protocols in IPCDN
who includes
persons probably not under CableLabs NDAs.
Perhaps a reference to section 7.7 of BPI+ specification (available at
http://www.cablelabs.com/specifications/archives/SP-BPI+_I10-030730.pdf
)
will that be sufice by indicate the Protocol extensibility for strong
algorithms
which are highly recommended.
7.7 Supporting Alternative Algorithms
The current BPI+ specification requires the use of 56-bit DES for
encrypting packet data, two-key triple DES for encrypting traffic
encryption keys, 1024-bit [RSA] for encrypting Authorization keys, and
1024-to-2048-bit [RSA] for signing BPI+ X.509 certificates. The choice
of key lengths and algorithms, while appropriate for current threat
models and hardware capabilities, may be inappropriate in the future.
For example, it is generally agreed that DES is approaching the end of
its practical usefulness as the industry standard for symmetric
encryption. NIST is currently overseeing the development and adoption of
a new standard encryption algorithm, commonly referred to as the
Advanced Encryption Standard, or AES. Given the nature of the security
services BPI+ is being asked to support (basic privacy at a level better
than or equal to that possible over dedicated wires, and conditional
access to RF data transport services) as well as the protocol's flexible
key management policy (i.e., setting of key lifetimes), DOCSIS-based
service providers will be justified in the continued reliance on DES
for, at least, the next five years. Nevertheless, at some future date,
DOCSIS Cable modems will need to adopt a stronger traffic encryption
algorithm, possibly AES. Adopting a new algorithm for packet data
encryption will not require a redesign of BPI+. The protocol's
consistent use of Type/Length/Value encoding of BPKM attributes, MAC
Header Extended Header elements, and security capabilities selection in
the authorization exchange guarantee BPI+'s extensibility. In fact,
changes in any of BPI+'s cryptographic algorithms, or associated key
lengths, will have no impact on the overall structure and operation of
the protocol.
-----Original Message-----
From: Wijnen, Bert (Bert) [mailto:[email protected]]
Sent: Thursday, September 23, 2004 6:12 AM
To: Ipcdn (E-mail)
Subject: [ipcdn] FW: DISCUSS: draft-ietf-ipcdn-bpiplus-mib-14
> COMMENT
>
> Please delete the second paragraph of the Abstract prior to
publication
> as an RFC.
>
> In the Abstract: s/DOCSIS1.1/DOCSIS 1.1/
OK
Thanks
Eduardo
I am forwarding IESG comments as I receive them.
Answers are fine. Pls do not yet submit a changed document untill we get
ALL the IESG comments. Should be around Tuesday next week.
Bert
-----Original Message-----
From: Russ Housley [mailto:[email protected]]
Sent: Wednesday, September 22, 2004 21:51
To: [email protected]
Subject: DISCUSS: draft-ietf-ipcdn-bpiplus-mib-14
Management Information Base for DOCSIS Cable Modems and Cable Modem
Termination Systems for Baseline Privacy Plus (Proposed Standard)
DISCUSS
The definition of docsBpi2CmPublicKey begins:
:
: docsBpi2CmPublicKey OBJECT-TYPE
: SYNTAX OCTET STRING (SIZE (74|106|140|204|270))
:
The selection of these few octet string sizes is inappropriate.
PKCS #1 encoding of an RSA public key is a SEQUENCE of two
INTEGERs. One example of an acceptable RSA public key that
cannot be accommodated by this definition follows. It is 139
octets.
0 30 137: SEQUENCE {
3 02 129: INTEGER
: 00 DD D8 49 85 DD 76 BE 9C 64 D2 6A 0C B3 3A 14
: 0B 37 A5 60 97 90 40 3D C0 C6 9C 01 FB D0 6F B6
: 49 56 E5 1A 44 F7 C7 1D 23 4C 91 A2 6F BE F7 9A
: D0 5F F0 88 9A 01 A2 0A 20 78 22 45 1A 9D 77 8F
: CA 14 3E 75 44 3C D6 67 16 21 E5 42 B5 EC BF 62
: 6C 09 0E 4D D9 79 D0 55 82 5C 9C FD B1 B9 B6 A6
: 5B 42 83 FA 90 1E 74 3F 5C 1C 1F D8 73 40 94 3C
: 9A 9F 2A 04 FE ED 8C 69 C3 0E 10 A6 3B 0B A7 A4
: CD
135 02 3: INTEGER 65537
: }
I do not believe that a five (or even ten) specific sizes can be
chosen that accommodate all valid RSA public keys.
The definition of docsBpi2CmtsAuthCmPublicKey has the same problem.
The definition of docsBpi2CmTEKDataEncryptAlg begins:
:
: docsBpi2CmTEKDataEncryptAlg OBJECT-TYPE
: SYNTAX INTEGER {
: none(0),
: des56CbcMode(1),
: des40CbcMode(2)
: }
:
And, the definition of docsBpi2CmTEKDataAuthentAlg begins:
:
: docsBpi2CmTEKDataAuthentAlg OBJECT-TYPE
: SYNTAX INTEGER {
: none(0)
: }
:
These same values are also used in the
docsBpi2CmCryptoSuiteDataEncryptAlg,
docsBpi2CmCryptoSuiteDataAuthentAlg, docsBpi2CmtsTEKDataEncryptAlg,
docsBpi2CmtsTEKDataAuthentAlg, docsBpi2CmtsIpMulticastDataEncryptAlg,
and docsBpi2CmtsIpMulticastDataAuthentAlg definitions.
None of the encryption algorithm choices is a strong encryption
algorithm. Also, the encryption algorithm choice do not
provide integrity, so they ought to be used with an integrity
algorithm, but none are specified. Can we get a strong
encryption algorithm added to the list? Can we get an strong
integrity algorithm specified? If not, the last few paragraphs of
of the Security Considerations need to be made much more forceful.
COMMENT
Please delete the second paragraph of the Abstract prior to
publication
as an RFC.
In the Abstract: s/DOCSIS1.1/DOCSIS 1.1/
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