[guardian-dev] Fwd: Forensic Analysis of the ChatSecure Android

[Hans-Christoph Steiner]

Wait, what?  Did they really just include this sentence in their abstract:

"we devise a technique able to decrypt them when the secret passphrase,
chosen by the user as the initial step of the encryption process, is
known. "

Am I wrong in reading this as:
"we can unlock chatsecure when we know the password"

.hc

Chris Ballinger:
> This looks like a silly report, and would apply to any other app using
> SQLCipher in a long running process, and in this case it's required to
> receive messages in the background. From a quick read it looks like the
> same passphrase is stored twice in memory for both the media and message
> store which helps their recovery process, but once you have physical access
> to a decrypted device in USB debugger mode there's all sorts of other ways
> you can recover it.
> 
> 
>> we devise
>> a technique able to decrypt them when the secret passphrase, chosen by
>> the user as the initial step of the encryption process, is known.
> 
> 
> It's pretty obvious how you'd decrypt a SQLCipher database when the
> passphrase is known.
> 
> Furthermore, we show how this passphrase can be identified and extracted
>> from the volatile memory of the device, where it persists for the entire
>> execution of ChatSecure after having been entered by the user, thus
>> allowing one to carry out decryption even if the passphrase is not
>> revealed by the user.
> 
> 
> This is how encrypted databases work and there's not really a way around
> it. You can encrypt the key in memory, but then you gotta keep the key for
> the key somewhere else in memory. Even on iOS where you can store keys in
> the device keychain, when the database is active the key needs to be in
> memory somewhere.
> 
> Finally, we discuss how to analyze and correlate the data stored in the
>> databases used by ChatSecure to identify the IM accounts used by the
>> user and his/her buddies to communicate, as well as to reconstruct the
>> chronology and contents of the messages and files that have been
>> exchanged among them.
> 
> 
> It's pretty easy to dump SQL tables..
> 
> 
> 
> 
> 
> 
> On Wed, Oct 26, 2016 at 10:23 AM, Nathan of Guardian <
> nathan at guardianproject.info> wrote:
> 
>> A great publication that really looks into detail on how we use
>> SQLCipher, IOCipher and CacheWord in ChatSecure Android, and many other
>> apps.
>>
>> Any thoughts on possible improvements to key management, data
>> reducation, etc, would be great to hear.
>>
>> ***
>>
>> Tweet: https://twitter.com/arxiv_org/status/790671148002398208
>>
>> and publication:
>> https://arxiv.org/abs/1610.06721
>>
>> Forensic Analysis of the ChatSecure Instant Messaging Application on
>> Android Smartphones
>>
>> Cosimo Anglano, Massimo Canonico, Marco Guazzone
>> (Submitted on 21 Oct 2016)
>> We present the forensic analysis of the artifacts generated on Android
>> smartphones by ChatSecure, a secure Instant Messaging application that
>> provides strong encryption for transmitted and locally-stored data to
>> ensure the privacy of its users.
>> We show that ChatSecure stores local copies of both exchanged messages
>> and files into two distinct, AES-256 encrypted databases, and we devise
>> a technique able to decrypt them when the secret passphrase, chosen by
>> the user as the initial step of the encryption process, is known.
>> Furthermore, we show how this passphrase can be identified and extracted
>> from the volatile memory of the device, where it persists for the entire
>> execution of ChatSecure after having been entered by the user, thus
>> allowing one to carry out decryption even if the passphrase is not
>> revealed by the user.
>> Finally, we discuss how to analyze and correlate the data stored in the
>> databases used by ChatSecure to identify the IM accounts used by the
>> user and his/her buddies to communicate, as well as to reconstruct the
>> chronology and contents of the messages and files that have been
>> exchanged among them.
>> For our study we devise and use an experimental methodology, based on
>> the use of emulated devices, that provides a very high degree of
>> reproducibility of the results, and we validate the results it yields
>> against those obtained from real smartphones.
>>
>>
>>
>> --
>>   Nathan of Guardian
>>   nathan at guardianproject.info
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> 
> 
> 
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