2021-01-21 13:40:28 +01:00
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</head><body>
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<p><span class="h1">Security Concerns</span>
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<br/><br/>
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2021-05-17 19:04:42 +02:00
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The standard Retro is not a good choice for applications
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2021-01-21 13:40:28 +01:00
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needing to be highly secure.
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<br/><br/>
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<span class="h2">Runtime Checks</span>
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<br/><br/>
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2021-05-17 19:04:42 +02:00
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The Retro system performs only minimal checks. It will not
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2021-01-21 13:40:28 +01:00
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load an image larger than the max set at build time. And
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stack over/underflow are checked for as code executes.
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<br/><br/>
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The system does not attempt to validate anything else, it's
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quite easy to crash.
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<br/><br/>
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<span class="h2">Isolation</span>
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<br/><br/>
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The VM itself and the core code is self contained. Nga does
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not make use of malloc/free, and uses only standard system
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libraries. It's possible for buffer overruns within the image
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2021-05-17 19:04:42 +02:00
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(overwriting Nga code), but the Retro image shouldn't leak
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2021-01-21 13:40:28 +01:00
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into the C portions.
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<br/><br/>
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I/O presents a bigger issue. Anything involving I/O, especially
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with the <span class="tt">unix:</span> words, may be a vector for attacks.
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<br/><br/>
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<span class="h2">Future Direction</span>
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<br/><br/>
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I'm not planning to add anything to the <strong>image</strong> side as, for me,
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the performance hit due to added checks is bigger than the
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benefits.
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<br/><br/>
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The story is different on the VM side. I've already begun taking
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steps to address some of the issues, using functions that check
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for overruns with strings and doing some minor testing for these
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conditions. I will be gradually addressing the various I/O
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related extensions, though it's unlikely to ever be fully guarded
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against attacks.
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<br/><br/>
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<span class="h2">Rationale</span>
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<br/><br/>
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2021-05-17 19:04:42 +02:00
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Retro is, primarily, a personal system. I'm running code I wrote
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2021-01-21 13:40:28 +01:00
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to solve problems I face. On the occasions where I run code sent
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to me by others, I read it carefully first and then run inside a
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sandboxed environment if I'm worried about anything in it.
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</p>
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</body></html>
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