full asn1 definition: https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/tpm2-tpmkey.git/tree/src/asn1.rs
0
0
0
@Foxboron I don't necessarily agree anymore to the word how I saw things then :-) The claim of endangering securiy was definitely wrong or at least a bit weak argument.
It's mostly about convenience (not about security) of not having to specify parent explitly, definitely something I can consider to drop. I also tested that openssl and tpm2-tools can handle files generated with my tool despite having that field.
Things that were not in the spec:
1. PolicyOr: I fully open code this including PolicyRestart calls.
2. Policy handle: I zero out this field in the encoded data.
I even looked at tpm2-tools and it does not really have anything at all for encoding arbitrary policies so I had to work on "without better knowledge". And without better knowledge this is the encoding I will use as basis for any kernel patch reviews or my own possible contributions.
It's mostly about convenience (not about security) of not having to specify parent explitly, definitely something I can consider to drop. I also tested that openssl and tpm2-tools can handle files generated with my tool despite having that field.
Things that were not in the spec:
1. PolicyOr: I fully open code this including PolicyRestart calls.
2. Policy handle: I zero out this field in the encoded data.
I even looked at tpm2-tools and it does not really have anything at all for encoding arbitrary policies so I had to work on "without better knowledge". And without better knowledge this is the encoding I will use as basis for any kernel patch reviews or my own possible contributions.
2
0
0
So the story with tpm2sh is that I only started it in August so that link feels like ancient history me in this fast-phased timeline :-)
If you have something other in mind and have good rationale for it, I want to align with that.The point is that tpm2sh is a reference model for me how kernel will handle the ASN.1 format.
If you have something other in mind and have good rationale for it, I want to align with that.The point is that tpm2sh is a reference model for me how kernel will handle the ASN.1 format.
2
0
0
@Foxboron If possible, could you point out the part of the current version that don't right to you?
I'm proactively concerned about this because I need to know what we want for kernel in the long run.
We don't want two separate formats so it is better to address this issue rather sooner than later :-) I'm not hanging myself to my implementation. I'm just working without better information (perhaps).
Actually no need to even look at the source code (unless you really want to). Just describe what goes wrong and I'll check whether I need to address something or if it is already addressed.
I'm proactively concerned about this because I need to know what we want for kernel in the long run.
We don't want two separate formats so it is better to address this issue rather sooner than later :-) I'm not hanging myself to my implementation. I'm just working without better information (perhaps).
Actually no need to even look at the source code (unless you really want to). Just describe what goes wrong and I'll check whether I need to address something or if it is already addressed.
2
0
0
Jarkko Sakkinen
jarkko
@Foxboron I have exactly one optional field "parentPublic".
Other than I'm willing to consider changes if there is need. My tools has been built quite rapidly so maybe you are not in-sync with very latest version but it is otherwise in par with the spec :-)
E.g., in very first version it did handle e.g. PolicySecret incorrectly but as of today it follows correctly the ASN.1 definition.
Other than I'm willing to consider changes if there is need. My tools has been built quite rapidly so maybe you are not in-sync with very latest version but it is otherwise in par with the spec :-)
E.g., in very first version it did handle e.g. PolicySecret incorrectly but as of today it follows correctly the ASN.1 definition.
1
0
0
Jarkko Sakkinen
jarkko
@Foxboron I need to try that out against my tool. It already nicely operates with openssl and tpm2-tools.
tpm2sh can generate keys with policies.
The set of commands is fairly limited but it is a subset that I pick to maximize coverage for the time being: or, secret and pcr.
Unfortunately spec is quite incomplete when it comes to PolicyOr but my tool generates the full PolicyRestart dance to the file. That way e.g. kernel in future can implement a functional executor.
What executor needs to done with output data:
1. Fill policy handle with active session handle.
2. Resolve handles for PolicySecret calls.
It would be cool to maintain some kind of interoperatibility with sbctl given the state of spec and that way sort of "fill out the blanks" :-)
For auth values in the latest version I've ended up to "<handle>:<hex>" type of list of mappings. Linear list of values is quite difficult to map when you have both purely auth value authenticated object and policies referencing to handles.
tpm2sh can generate keys with policies.
The set of commands is fairly limited but it is a subset that I pick to maximize coverage for the time being: or, secret and pcr.
Unfortunately spec is quite incomplete when it comes to PolicyOr but my tool generates the full PolicyRestart dance to the file. That way e.g. kernel in future can implement a functional executor.
What executor needs to done with output data:
1. Fill policy handle with active session handle.
2. Resolve handles for PolicySecret calls.
It would be cool to maintain some kind of interoperatibility with sbctl given the state of spec and that way sort of "fill out the blanks" :-)
For auth values in the latest version I've ended up to "<handle>:<hex>" type of list of mappings. Linear list of values is quite difficult to map when you have both purely auth value authenticated object and policies referencing to handles.
1
0
0
Jarkko Sakkinen
jarkko
https://thenewstack.io/ffmpeg-to-google-fund-us-or-stop-sending-bugs/ :-----------------------)
0
1
2
Jarkko Sakkinen
jarkko
0
0
2
Jarkko Sakkinen
jarkko
1
0
1
Jarkko Sakkinen
jarkko
Edited 6 months ago
one aspect in security, which has been wrong even in some of the linux foundations pages from time to time is that they differentiate answers between "incorrect password" and "acount does not exist". this should be obviously opaque.
it allows to query which sites user has an account, which is useful information in wrong hands already.
#infosec #oracle
it allows to query which sites user has an account, which is useful information in wrong hands already.
#infosec #oracle
0
2
1
Jarkko Sakkinen
jarkko
when it comes to infosec i'm glad at least that the "era of silly security questions" is over.
it was super-frustating to copy-paste set-and-forget one-time pad answers to questions such as "what was your mothers maiden name", when they were still a thing.
i don't know who invented them but the person should get some kind of worst invention of IT ever award or something.
#infosec #password
it was super-frustating to copy-paste set-and-forget one-time pad answers to questions such as "what was your mothers maiden name", when they were still a thing.
i don't know who invented them but the person should get some kind of worst invention of IT ever award or something.
#infosec #password
1
0
2
Jarkko Sakkinen
jarkko
Next thing I'll add to tpm2sh is direct support for keyctl syscall and key re-creation in kernel. After that I can revisit asymmetric keys kernel patch set :-)
0
0
0