On Monday, December 21, 2015 at 6:56:03 PM UTC-5, jh...@emocha.com wrote: > > > Small amounts of data do not seem to crash it. In my app I either get a > very small amount of data, or a very large amount if data. A small amount > is 7-15kB. A large amount is over a 1MB > > Data size (in bytes), result: > > 1,180,504 locked > > 2,709,738 locked > > 8,727,128 locked > > 7,636 ok > > 11,429 ok > > 11,512 ok > > 11,961 ok > > 7,672 ok > > 11,460 > > 975,913 ok (outlier) > > 11,600 ok >
Yeah, the results look about right. Mobile devices only have 512MB to 1GB of memory, and they *don't* have page files. You should get an out of memory exception or similar if you try to read 2GB or 8GB into memory. Mobile devices usually require you to decrypt a range (like a 64KB block), and then display the range (in a custom UIViewController). It can be tricky business. Now, the lock you are seeing could be two things (maybe more). First, it could be CocoaTouch throwing an Objective-C exception. In this case, Crypto++ code would be no wiser because its not a C++ exception. Second, it could be the Crypto++ library spinning on placement operator new. I have never seen how the library performs in this situation. Related to the second point, there's a brief discussion at AllocatorWithCleanup::allocate (http://www.cryptopp.com/docs/ref/class_allocator_with_cleanup.html#a213d3399b5e89e61f2bf4fc512da289f). You need to look at misc.cpp, line 195 or so (http://www.cryptopp.com/docs/ref/misc_8cpp_source.html#l00195). Pay particular attention to the call to CallNewhandler around line 140 (http://www.cryptopp.com/docs/ref/misc_8cpp_source.html#l00140). Now, to work around all of this, I think you will need to Pump data in blocks of say, 4096. I *think* the source does this, but I don't believe it performs a Flush. So data accumulates in the Filter or Sink. This should be a non-hard flush. It should not be a MessageEnd() either. See the code below. Jeff ********** int main(int argc, char* argv[]) { static const unsigned int BIG_SIZE = 2U * 1024U * 1024U * 1024U; static const unsigned int BLOCK_SIZE = 4096U; try { SecByteBlock key(32); OS_GenerateRandomBlock(false, key.data(), key.size()); cout << "Key: "; ArraySource as(key.data(), key.size(), true, new HexEncoder(new FileSink(cout))); cout << endl; CFB_Mode<AES>::Encryption enc; enc.SetKeyWithIV(key.data(), key.size(), key.data()); MeterFilter* meter; StreamTransformationFilter stf(enc, meter = new MeterFilter(new FileSink("null.enc"))); SecByteBlock data(BLOCK_SIZE); memset(data, 0x00, data.size()); unsigned int remaining = BIG_SIZE; while(remaining) { if(remaining % (1024*1024) == 0) { cout << "Processed: " << meter->GetTotalBytes(); cout << ", Available: " << stf.MaxRetrievable() << endl; } const unsigned int req = STDMIN(remaining, BLOCK_SIZE); stf.Put(data, req); stf.Flush(false); remaining -= req; } } catch(const Exception& ex) { cerr << ex.what() << endl; } return 0; } -- -- You received this message because you are subscribed to the "Crypto++ Users" Google Group. To unsubscribe, send an email to cryptopp-users-unsubscr...@googlegroups.com. More information about Crypto++ and this group is available at http://www.cryptopp.com. --- You received this message because you are subscribed to the Google Groups "Crypto++ Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to cryptopp-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
