Signature verification #16

somecookie · 2018-12-15T18:32:54Z

This PR add the following new features:

The signature verification of a status-vote consensus in both JavaScript and python
A demo of the the signature verification in python
Tools to update the signing keys

… path_selection

The script is at examples/signature_verification.py. You can either run it with the key at verif/my_public2048.pem and the signature at verif/my_signature.txt (Lines 26-27 and 34-36 must be commented out since those are the lines that check the key in the consensus corresponds to the one at /var/lib/tor/cached-certs) or with the first key of the consensus (verif/public.pem) and the first signature (verif/signature.txt).

…l/lighttor into signatureVerification

… signatureVerification

We can now download the info of the authority signing keys and save the pem, modulus and exponent to a json file

We can now save the following information about the signing keys of the authority to a JSON file: -key in pem format -key modulus -key exponent

plcp · 2018-12-15T20:10:21Z

js-client/src/signature.js

+/**
+ *  This function verifies the given raw consensus
+ *
+ *   Note 1: TOR does not perform a full PKCS#1 v1.5 signature (RFC 2313) as mentioned in the TOR's reference.


Nice one 👍

plcp · 2018-12-15T20:41:10Z

js-client/src/signature.js

+ *           RFC 2313 for more details), however the digest is not wrapped into the data structure described in the
+ *           subsection 10.1.2. This is the reason why RSA is performed manually.
+ * 
+ *   Note 2: <script src="http://peterolson.github.com/BigInteger.js/BigInteger.min.js"></script> must be included in the HTML file using this function.


From what I understand here, implementing our own little RSA to get around Tor quirks is a good thing, however the "rooling your own" vibe together with Javascript and a third-party library may not be the best we can do.

For the descriptors, we can improve it a bit by using a "stronger" implementation (like HACL* ported in WebAssembly that we can reuse for the ntor handshakes) to validate router-sig-ed25519 whenever possible.

For the consensus, I don't see such feature, thus I recommend to directly use the native BigInt without poly-fill (just as we need to migrate away from userland to browserland cryptographic implementation).

I'm stating this comment as a reminder, for later integration in a more formalized roadmap.

I say no on verifying the router-sig-ed25519 version for now. I agree it could be a nice feature that we can add to a "roadmap" or "feature request", but I'd rather focus on getting this code in for now. We can always change it later.

@Native BigInt: this does not work, and will not work for some time to come. Currently only Chrome supports native BigInt. Since this is only a few lines of code, I would again prefer just to merge this, and then once the native code lands, we can see about dealing with it then.

+1 for both points

About router-sig-ed25519, I've opened #18 to document this request.

I'm sorry, I misread documentation about BigInt – and you're right, we do need a polyfill. I've opened #17 to document this request and I'm favorable to merging while relying on BigInteger.js.

plcp · 2018-12-15T20:42:35Z

js-client/src/signature.js

+ *                       modulus: modulus        //the modulus of the key as a string
+ *                       exponent: exponent      //the exponent of the key as a string
+ *                   }
+ * @param {Number} minimal the minimal percentage of the signatures that must be verified in order to verify the consensus


Default (safe) value needs to be documented, such as a warning (enclosed within <pre> tags for example) about the potential misuse of this parameter (making explicit recommendations on the API usage).

Good point @plcp! @somecookie could you explicitly add the default value to the documentation? I think stem sets it to 0.5 as well right?

plcp · 2018-12-15T20:46:23Z

js-client/src/signature.js

+    }
+
+    return padded_hash.substring(sep_index + 2)
+}


Missing newline

plcp · 2018-12-15T20:49:39Z

Nice work again! This need serious review, such as you other two PRs… hopefully I may be able to get into it seriously as I got some vacations for the end of the year.

plcp · 2018-12-15T20:51:25Z

Note: instead of including dumped .json in js-client/demo or tools, you may prefer including documentation to generate these where they are used.

plcp · 2018-12-17T19:01:28Z

It could be nice to integrate BigInteger.js in the bundled distribution at some point as it'll become a core functionality of lightnion – however, this may not need be a requirement today in order to focus on merging this.

somecookie · 2018-12-20T15:52:10Z

@wouterl this PR has also the same issue (a is undefined) as the one I showed you for the path selection

…l/lighttor into signatureVerification

laurent-girod · 2020-01-20T13:04:05Z

The branch was merged into master when an other branch was merged.

somecookie and others added 30 commits October 27, 2018 17:19

Implements a demo of the path selection in client

e540365

Implements the path selectio in the client

bcf2310

Implements the parsing of the headers of the consensus

11273a6

Rewrite the code of the parser for the headers

e55e0a0

Implement the parsing of the authority section of the consensus

3adb0b7

Implement the parser for the consensus

2b6b576

Reorder files

4947d92

Remove not working files

fe9c9e4

Merge branch 'master' of https://github.com/spring-epfl/lighttor into…

4b2aaaa

… path_selection

Speed up the parsing by replacing the splicing of each line by an index

87b9f1c

Crude signature verification, mimicking stem

240b43b

Merge branch 'signatureVerification' of https://github.com/spring-epf…

4ff26dd

…l/lighttor into signatureVerification

Finish the demo of the signature verification

32e444e

TODO

08122ee

Delete get_JSON_of_descriptors.py

fa83ba3

Delete consensusParser.js

b5c8835

Delete beautify_cons.txt

b54ae82

Delete test.consensus.txt

cf4281c

Delete parser.html

bbb62f9

Merge branch 'signatureVerification' of https://github.com/spring-epf…

f11db0a

…l/lighttor into signatureVerification

Merge branch 'master' of https://github.com/spring-epfl/lighttor into…

1a7ac3b

… signatureVerification

Move keys to tool and add new function to it

b59ed70

We can now download the info of the authority signing keys and save the pem, modulus and exponent to a json file

Move keys.py to tools and add a new function to it

caa28ac

We can now save the following information about the signing keys of the authority to a JSON file: -key in pem format -key modulus -key exponent

Fix small issue in keys

c44cc74

Implement the signature verification in JavaScript

5473884

Move the signature code to its own file in lnn

bf84c15

Implement a tool to download the chutney's key

4395792

Move the js signature code to its own file

d3cea67

somecookie requested a review from wouterl December 15, 2018 18:32

plcp reviewed Dec 15, 2018

View reviewed changes

js-client/src/signature.js

}

return padded_hash.substring(sep_index + 2)

}

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plcp Dec 15, 2018

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Missing newline

This was referenced Dec 17, 2018

Migrate away from BigInteger.js to either BigInt or JSBI polyfill #17

Open

Validate router-sig-ed25519 #18

Open

Ricardo Ferreira Ribeiro added 3 commits December 20, 2018 21:47

Delete path_selection.html

77e9bc2

Fix keys download for chutney

497c30c

Merge branch 'signatureVerification' of https://github.com/spring-epf…

f88e527

…l/lighttor into signatureVerification

laurent-girod closed this Jan 20, 2020

laurent-girod deleted the signatureVerification branch January 20, 2020 13:04

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Signature verification #16

Signature verification #16

somecookie commented Dec 15, 2018

plcp Dec 15, 2018

plcp Dec 15, 2018

wouterl Dec 17, 2018

plcp Dec 17, 2018

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wouterl Dec 17, 2018

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plcp commented Dec 15, 2018

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plcp commented Dec 17, 2018

somecookie commented Dec 20, 2018

laurent-girod commented Jan 20, 2020

Signature verification #16

Signature verification #16

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laurent-girod commented Jan 20, 2020