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POC++ Converting binary data to a hex string and back
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copied!<p>I have a matching pair of static functions in a utility class that I use to convert between binary data (unsigned characters) and it's string representation (a-f and 0-9). They seemed to work correctly but recently I tried to compile my code under Visual C++ (2010 Express) and to my dismay, they cause nothing but heap corruption errors. What am I doing wrong?</p> <pre><code>void Utility::string_to_binary(const std::string source, unsigned char* destination, unsigned int length) { unsigned int effective_length = min(length, (unsigned int) source.length() / 2); for(unsigned int b = 0; b < effective_length; b++) { sscanf(source.data() + (b * 2), "%02x", (unsigned int*) &destination[b]); } } void Utility::binary_to_string(const unsigned char* source, unsigned int length, std::string& destination) { destination.clear(); for(unsigned int i = 0; i < length; i++) { char digit[3]; sprintf(digit, "%02x", source[i]); destination.append(digit); } } </code></pre> <p><strong>Edit: Here's a complete program that illustrates the problem.</strong></p> <pre><code>#include <iostream> #include <hdcs/Utility.h> using namespace std; int main(int argc, char* argv[]) { //Generate some data unsigned int size = 1024; unsigned char* data = new unsigned char[size]; //Convert it to it's string representation string hex; Utility::binary_to_string(data, size, hex); //Output it to the screen cout << hex << endl; //Clear the data buffer memset(data, 0, sizeof(unsigned char) * size); //Convert the hex string back to binary Utility::string_to_binary(hex, data, size); //Cleanup delete[] data; } </code></pre> <p>The error occurs on <code>delete[] data</code>.</p>

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