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SHA-1 (2005-6-21)This is a C++ class that implements the Secure Hash Algorithm SHA-1. The purpose of the algorithm is to calculate a strong hash of given bit string. By "strong", we mean that it is very difficult to find a different bit string that results in the same hash. It is similarly difficult, using only the hash, to determine the original bit string. SHA-1 produces a 20 byte (160 bit) hash. Download
Class UsageThe class is called SHA1. The API consists of four methods: SHA1::SHA1() is the class constructor void SHA1::addBytes( const char* data, int num ) processes bytes into the hash.
unsigned char* SHA1::getDigest() completes the hashing process and returns the final hash. The SHA1 instance should not be used after calling this method.
static void SHA1::hexPrinter( unsigned char* c, int l ) prints bytes to stdout in hexadecimal format.
ExampleThe following program will print one line to stdout: a9 99 3e 36 47 06 81 6a ba 3e 25 71 78 50 c2 6c 9c d0 d8 9d
#include <string.h>
#include <stdlib.h>
#include "sha1.h"
int main(int argc, char *argv[])
{
#define BYTES "abc"
SHA1* sha1 = new SHA1();
sha1->addBytes( BYTES, strlen( BYTES ) );
unsigned char* digest = sha1->getDigest();
sha1->hexPrinter( digest, 20 );
delete sha1;
free( digest );
}
LicenseI couldn't find a free SHA-1 implementation for C++ so I wrote my own. I wrote the Python version first and then the C++ one. The source code has an open source license (the so-called "MIT License" ) which allows it to be used in commercial software. LinksSecure Hash Standard (FIP 180-1) is the official document from the U.S. government which defines the algorithm. Wikipedia has a very helpful article on SHA.
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