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POCCCrypt Crash (EXC_BAD_ACCESS)
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copied!<p>I am trying to decode some data however when the data is larger than 520,000 (bytes? It's <code>[data length]</code>) my app will crash on debugger on the <code>CCCrypt</code> line, or if detached from debugger it just freezes and doesn't actually crash properly (Spinner keeps going round but app completely freezes).</p> <p>This is my decrypt code:</p> <pre><code>char *key = ENCRYPTION_KEY; NSUInteger dataLength = [data length]; uint8_t unencryptedData[dataLength + kCCKeySizeAES128]; size_t unencryptedLength; CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionECBMode, key, kCCKeySizeAES128, NULL, [data bytes], dataLength, unencryptedData, dataLength, &unencryptedLength); NSData *output = [[NSData alloc] initWithBytes:unencryptedData length:unencryptedLength]; return output; </code></pre> <p>EDIT ----------</p> <p>Following Hejazi's answer below, I now have this, but it still doesn't work :(</p> <pre><code>- (NSData *)decodeSnapDataInBackground:(NSData *)data { char *key = ENCRYPTION_KEY; NSUInteger dataLength = [data length]; uint8_t unencryptedData[dataLength + kCCBlockSizeAES128]; size_t unencryptedLength; size_t unencryptedDataLength = dataLength + kCCBlockSizeAES128; CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionECBMode, key, kCCKeySizeAES128, NULL, [data bytes], dataLength, unencryptedData, unencryptedDataLength, &unencryptedLength); NSData *output = [[NSData alloc] initWithBytes:unencryptedData length:unencryptedLength]; return output; } </code></pre> <p>EDIT 2 -----</p> <p>It seems this problem occurs when I perform the decoding on a background thread. I was using this:</p> <pre><code>dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void){ </code></pre> <p>When I removed it, it now decodes large blocks of data fine.</p> <p>Why would this be, and is there any way I can get this to work on a background thread?</p> <p>Thanks</p>

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