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There are no secure smartphones

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Re: There are no secure smartphones

#81

Post by viraptor »

NateLawson wrote: post #73
gue5t wrote: post #8

Earlier quoted context omitted.

Rather than asking us to take this on faith, do you know of any resources where it's possible to learn about the technical details hidden "in the weeds"? What I'm able to find looking around amounts to Apple verifying that the firmware loaded matches what's expected--but that's simply checking the binary, and doesn't give users any assurance whether that baseband enables backdoors or not. I didn't find anything about…

For one example, see the Android kernel for Qualcomm HSIC baseband interface (baseband-qct-mdm-hsic.c) https://git.sphere.ly/Lloir/android_kernel_htc_evitareul/tre... The way manufacturers "mitigate" baseband to main CPU compromise is by using a protocol that allows no initiation from the peripheral device (baseband). It can only talk to the main CPU via a serial-like protocol, not access its memory directly. Other r…

There's a difference between "what it does" and "what it can do" however. I mean, whatever well-defined interface is used, hardware design may leave other options open and unused.

Kind of like vmware provides nice interface for folder sharing, but in practice can just write directly to whatever files/memory they want.

Re: There are no secure smartphones

#82

Post by est »

mitchtbaum wrote: post #37
scientes wrote: post #16

Or you can just use WIFI and turn the baseband off like I do. The cell companies are all crooks anyways (in the US), and I don't want to do business with them.

On Android: 1. Put # #4636# # into the Dialer (or use any application available on the Market like 4636 — takes you to the same service screen) 2. Choose Phone Information 3. Press Turn off radio (source) http://forum.xda-developers.com/showpost.php?s=c8b62d54e971b... (more discussion) http://android.stackexchange.com/questions/7133/how-do-i-tur...

for easier remembering and correctly formatted:

    *#*#INFO#*#*

Re: There are no secure smartphones

#83

Post by venomsnake »

beatpanda wrote: post #34
gue5t wrote: post #3

The folks at http://neo900.org/ are well aware of this and that phone is designed accordingly (details at http://neo900.org/faq#privacy ). Hype-driven products like BlackPhone misrepresent their devices as being perfectly secure when this significant attack vector is completely unmitigated. On the Neo900, the modem is connected via USB (bus; there is no physical connector) which means it doesn't have DMA. There is no…

>somehow even among people who describe themselves as "hackers", most just want to run Android or iOS and buy/run closed-source apps, and are more interested in Javascript and employment [read: eating, having shelter] than reverse-engineering and doing things that have never been done before. How many opportunities are there to work on secure communications software full time and still put food on the table?

A LOT. But on the other side of the fence. LEO are paying like mad for secure communication solutions. And breaking into others.

Re: There are no secure smartphones

#86

Post by pslam »

NateLawson wrote: post #76
pslam wrote: post #13

Earlier quoted context omitted.

> On the Neo900, the modem is connected via USB (bus; there is no physical connector) which means it doesn't have DMA. You'll find the modem on most smartphones is connected via USB - or rather its chip-to-chip version, HSIC. For SoCs where it's on-die - on the same bus/fabric - they will (if it's not an idiotic design) use an IOMMU of some sort, to prevent DMA from having access outside of its sandbox. Even if it's…

There is no IOMMU in USB. You've got it backwards: the IOMMU in PC's is on the host side of the USB controller, not the device side. There's an easy way to tell. Does the bus carry memory addresses? Then it supports DMA. Does it just send messages? No DMA to protect against. The USB controller on a PC does support DMA. The OS device driver allocates buffers and passes them to the controller to fill. If it's properly…

This is exactly what I'm saying.

"DMA" as the parent puts it implies a core in the same SoC, rather than external. It would be hair brained to let this have unfiltered access to the fabric. However, that's exactly how older SoCs used to do it - in fact it used to be in charge and the AP shoved behind the IOMMU.

These days nobody I know of is stupid enough to have that arrangement. So it's not really a choice of "DMA" vs USB. External isn't buying much, unless you distrust the fabric filter (IOMMU), which isn't necessarily paranoid... but a level beyond this kind of system decision.

Re: There are no secure smartphones

#87

Post by tlrobinson »

bit_razor wrote: post #43
xlayn wrote: post #7

Earlier quoted context omitted.

I have kind of confusion, your rant about people on HN not understanding that "re-programmable computers that, at a low level, run the code you ask them to" and the fact that no one has a complete ownership of all the parts inside that phone or any other option makes difficult to sustain an option as secure, because those options would comprise several different cpus. The closest way I can see to get something to be…

To add to this madness, even if you design your own chips and software stack, the fab that printed your chips might have modified your design. Perhaps you can design a chip that's resilient to modifications? Is it possible to build a chip that only executes instructions encrypted by your key? I'm not talking about just decoding to L1 and executing plaintext there, but having a full pipeline that can only work on your…

How about implementing your CPU on a FPGA? It should be easier to verify the physical hardware hasn't been tampered with.

e.x. https://en.wikipedia.org/wiki/Amber_(processor_core)

Of course it would be orders of magnitude slower than a modern CPU.

Re: There are no secure smartphones

#88

Post by CaptSpify »

peteretep wrote: post #63

The article asserts: > It would, in my view, be abject insanity not to > assume that half a dozen or more nation-states (or > their associated contractors) have code execution > exploits against popular basebands in stock. To me this ignores the flip-side of the argument. If US intelligence services really thought the Chinese and Russians could remotely and invisibly hack all/most smartphones then no-one with access…

Couldn't that same argument be used on routers/switches/other equipment that we find back-doors in all the time?

Re: There are no secure smartphones

#89

Post by chongli »

seba_dos1 wrote: post #35
pslam wrote: post #13

Earlier quoted context omitted.

> On the Neo900, the modem is connected via USB (bus; there is no physical connector) which means it doesn't have DMA. You'll find the modem on most smartphones is connected via USB - or rather its chip-to-chip version, HSIC. For SoCs where it's on-die - on the same bus/fabric - they will (if it's not an idiotic design) use an IOMMU of some sort, to prevent DMA from having access outside of its sandbox. Even if it's…

"Evil USB" (or "bad USB") is possible thanks to the U part of USB - universal. If you connect a pendrive to your computer, it can easily say that it's a keyboard, because your computer cannot easily verify that you haven't just connected a keyboard. It would need to ask you in some trustworthy way to be sure, which sometimes can be problematic. OTOH, on the device like Neo900 it is well-known what kind of device is c…

If you connect a pendrive to your computer, it can easily say that it's a keyboard, because your computer cannot easily verify that you haven't just connected a keyboard.

Sure it can. Just pop up a dialogue on the screen displaying a random character string and ask the user to type the string. The dialogue could simply instruct the user to unplug and cast suspicion upon a device that is pretending to be a keyboard.

Re: There are no secure smartphones

#90

Post by est »

seba_dos1 wrote: post #39
hardwaresofton wrote: post #25

Would really love to see this upvoted more. This basic truth should be common knowledge for privacy-minded or security-minded technologists/developers. There are lots of reasons GSM won't/is hard to make work. What are the options? As more and more carriers in the USA provide wifi-dongles that are connected to 3G, maybe it's better to just do that, and move off making calls directly from your phone completely? For ex…

LTE is basically VoIP, a 180° change from the monstrosity of 3G, although the providers still manage to fail spectacularly at it. https://media.ccc.de/v/32c3-7502-dissecting_volte

Holyshit, you can play so much with VoLTE moved to Application Processor.
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