#Eureka cryptext how to
#Eureka cryptext code

The important thing to note here is that the service only encrypts mails sent by one Criptext user to another. Attachments are encrypted as well they are stored on Criptext's Amazon Web Services servers though the encryption keys for those are saved on user devices. Encrypted mailsĬriptext says that every email is encrypted with a unique key. If it isn't delivered within 30 days, it's deleted from the server as well. The email is stored on the server until it is delivered in this case. The only exception to this is when the message is un-deliverable say when the recipient's device is offline. How does this work? According to the official documentation, Criptext passes the mail through their server for a moment and it's deleted once the mail is delivered.

It is not cloud-based like Gmail or Outlook Criptext emails are not stored on servers permanently, they are only stored on your device using end-to-end encryption. There is something you should know about Criptext. (Okay, I know I just said I won't compare the two, but this is the only time I do it in the article). The applications for Criptext are open-source, but the servers are not.

#Eureka cryptext how to

Knowing the crypto APIs will hopefully be enough to figure out how to access the public key in the PFX file.Before we get started, allow me to say that this article isn't about Criptext vs Protonmail, so we're not going to discuss which one's better. Step into that handler and see what crypto APIs it calls. Therefore it should exit the comparison loop and go to a handler for that verb. It should be in the middle of comparing the verb in question. It will probably be in a loop comparing the verb specified on the command line with each verb within the program.

#Eureka cryptext code

When the read breakpoint triggers, start stepping through the code that read the string. Put a read breakpoint within the DLL's memory on the first byte/word of the string containing that verb. Set the command line in the debugger to use the verb you found as well as your test PFX file. Then load rundll32.exe into a debugger (ie Windbg). Hopefully you'll figure out which is the right verb. Try running rundll32.exe using the verb(s) you pick with a PFX as input. Determine which verb(s) is most likely to support opening PFX files. You should see the various verbs indicated above. Dump the ASCII/UNICODE strings in the file. Here are a couple of suggestions on reverse engineering cryptext.dll to see how it works. The fact that it is a COM component means it is (almost surely) using unmanaged crypto APIs. So there's no obvious way to programmatically access it from. Based on OLEVIEW, it only implements the IUnknown interface. Although it contains an embedded typelib, using TLBIMP to create an interop assembly doesn't provide access to any interesting methods or properties. From the registry you can see which verb is associated with each file type.Ĭryptext.dll is a COM component.

It is invoked using rundll32.exe along with a 'verb'. If you search the registry for cryptext.dll you'll see that it handles a lot of different file types (CERs, CRLs, crypto store, etc.). What I found is that cryptext.dll is the 'Crypto Shell Extensions' and handles PFX files. I looked into this a while to see if I could determine how the Cert Manager is able to open a PFX file.