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location United Kingdom
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visits member for 3 years, 7 months
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Pentester, ex-developer, security researcher, reverse engineer, electronics tinkerer, internet activist, zombie eradicator, promulgator of useless facts, shrubbery inspector, bacon aficionado, devourer of donuts.

Strengths: Security, Crypto, Win32 API, C#, .NET, PHP, x86 assembly

All answers and comments are encrypted with ROT256-ECB.

Opinions are my own. Advice provided with no warranty.


Mar
23
comment Can a Trojan hide itself, so its activity doesn't appear in task manager process?
@CodesInChaos Injecting a DLL simply allows the hooks to be inserted within the process more easily, as the code already exists. The alternative vector is to use VirtualAllocEx / WriteProcessMemory / VirtualProtectEx / CreateRemoteThread to either inject code and a new running thread to patch the IAT, or directly patch the IAT with "remotely" allocated code caves, without creating the remote thread.
Mar
23
comment Would Insecure Direct References and SQL Injection be solved by using Row-Level Security and Per-User Connection Strings?
@NeilMcGuigan Well, for a start, you need a mechanism to provision those accounts. Which means your provisioning user needs the ability to create new users and set their privileges - not ideal. What situation are you running into with "dynamic identifiers"? Every time I've heard that problem, it's been a use-case for a non-relational database (e.g. Redis / MongoDb) or a misunderstanding of constraints / normal form.
Mar
22
comment Is it unwise to use Redis to store PII, private keys, and other secrets?
While I understand the need for risk analysis, surely the solution here isn't doing away with Redis, but rather using hardware that is known-safe against Rowhammer? It seems that modern UEFI patches are decreasing the DRAM refresh timings, and there's currently no known practical attack against ECC.
Mar
22
comment Are there different degrees of “confidentiality”? What is the best way for a psychologist to maintain confidentiality of communications with patients?
Yup. Pretty much.
Mar
20
comment Are there different degrees of “confidentiality”? What is the best way for a psychologist to maintain confidentiality of communications with patients?
@StanShunpike I wouldn't rank them in any order - they're all insecure. Don't use any of them to send patient information. The exception is if you're sending emails encrypted (e.g. with PGP) but this doesn't sound appropriate for what you're doing.
Mar
20
comment I have registered a .com domain and received an e-mail from domainadmin.com
Feel free to draw your own conclusions. Mine is that it's legit.
Mar
20
comment I have registered a .com domain and received an e-mail from domainadmin.com
@redCodeAlert From what I can tell, the site itself is not run by ICANN, but a 3rd party which handles ICANN registrations.
Mar
20
comment I have registered a .com domain and received an e-mail from domainadmin.com
Did you even Google it? The top three results explained what domainadmin.com is about, what the email means, and its legitimate status. In fact, Google's first search suggestion was "domainadmin.com legit".
Mar
20
comment Reducing hash output length
Please go back and edit your question to include the details I mentioned above. At the moment this is a vague question which cannot be answered, and as it stands it's a direct duplicate of the one M'vy linked.
Mar
20
comment Reducing hash output length
I still don't follow why you need to shrink the size of the hash down to 10 bytes. What's the reasoning behind this? You've asked whether it's "reasonably" secure "for your needs", but you haven't defined your needs, your threat model, your application's function, or the reason for reducing the hash size in the first place.
Mar
20
comment Reducing hash output length
CRC is not a cryptographically secure measure against modification. It's a checksum designed to detect corrupted data, not forging.
Mar
20
comment Reducing hash output length
@user30024 Thomas didn't say collisions don't matter. He's saying there's a difference between a preimage and a collision. In your case you're talking about checking for modified input (collisions matter, preimages are irrelevant) whereas that question concerned hashing passwords (preimages matter, collisions are mostly irrelevant).
Mar
20
comment Reducing hash output length
@user30024 Of course collisions are an issue. If there are collisions, you have a different message which is accepted as correct. Why do you want to reduce it, anyway? 20 bytes isn't exactly a lot to store or transmit.
Mar
20
comment is return-to-libc attacks possible Now?
Ah, it's a PLT.
Mar
20
comment Help understanding VPN
This doesn't really answer the question, beyond a (pretty poor) definition of the term "VPN", which you've copied verbatim from the site.
Mar
20
comment Cross Origin Resource Sharing question
How are you hosting your local code? If it's just as a direct file path into your browser, it may ignore SOP as you've not got an origin. Keep in mind that the SOP for CORS is browser-enforced, not server-enforced.
Mar
20
comment Is this a sensible way to encrypt user data?
@StuartP.Bentley scrypt will likely be used as a KDF to derive a key from the user's password.
Mar
20
comment is return-to-libc attacks possible Now?
The linker optimisation mentioned there isn't exclusive to Microsoft toolchains. Actually - can you post the disassembly that you've seen? It may be a direct syscall rather than an actual call to system().
Mar
20
comment Are there different degrees of “confidentiality”? What is the best way for a psychologist to maintain confidentiality of communications with patients?
@StanShunpike SMS is cleartext, so using it to transfer patient records is a HIPAA violation. Same goes for standard pagers. Voice communications over cellular networks are encrypted, and their contents are protected legally (wiretapping laws), so I would imagine you'd be ok with that. Though I'd refrain from leaving sensitive information about patient care specifics on voicemail regardless - just ask them to call you back to discuss things.
Mar
20
comment How Secure is my Application?
It's not as trivial as pulling it off the wire. Note that you can still encrypt the traffic inside HTTPS if you're trying to avoid the user getting access to the binaries. However, it seems you're trying to implement what amounts to a DRM system, which is inherently impossible: the user's machine is their own to do with as they wish, so they will get access if they want. In fact, all they need to do is write their own client that pulls down the binaries and saves them. You can't stop that - you can only make it a little harder.