openwall / openwall/john

ProtonMail offline password recovery

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#4,658 3 comments 0 reactions 0 assignees View on GitHub

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new format
Dominant language
C
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Description

ProtonMail uses OpenPGP keys, but with custom bcrypt-based key derivation (prior to the usual s2k?). We can probably add a format that would crack ProtonMail login password (in their one-password mode, or the mailbox password otherwise?) given an OpenPGP private key extracted from a memory dump and bcrypt salt and SRP modulus obtained when trying to log in, as I explained here:

https://github.com/ProtonMail/WebClient/issues/38#issuecomment-811028444

Anyone wants to try and implement this?

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the linked ProtonMail WebClient issue comment, since no John the Ripper file, test, or entry point is named here. Determine the exact key-derivation inputs and password modes before locating the appropriate format implementation. Done means a validated format that reproduces ProtonMail's derivation and is covered by representative test data.

Written by the indexing model from the issue text.

Assessment

Tech stack
c
Domain
cryptography, security
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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