Add an example program demonstrating hash API

[libs/crypto.git] / examples / checksum.cpp

diff --git a/examples/checksum.cpp b/examples/checksum.cpp
new file mode 100644 (file)
index 0000000..f5ef853
--- /dev/null
+++ b/examples/checksum.cpp
@@ -0,0 +1,75 @@
+#include <list>
+#include <string>
+#include <msp/core/application.h>
+#include <msp/core/getopt.h>
+#include <msp/crypto/md5.h>
+#include <msp/crypto/sha2.h>
+#include <msp/io/file.h>
+#include <msp/io/print.h>
+
+using namespace std;
+using namespace Msp;
+
+class Checksum: public Msp::RegisteredApplication<Checksum>
+{
+private:
+       bool do_md5;
+       bool do_sha256;
+       bool do_sha512;
+       list<string> files;
+
+public:
+       Checksum(int, char **);
+
+       virtual int main();
+private:
+       template<typename H>
+       void process_file(const std::string &);
+};
+
+Checksum::Checksum(int argc, char **argv):
+       do_md5(false),
+       do_sha256(false),
+       do_sha512(false)
+{
+
+       GetOpt getopt;
+       getopt.add_option("md5", do_md5, GetOpt::NO_ARG);
+       getopt.add_option("sha256", do_sha256, GetOpt::NO_ARG);
+       getopt.add_option("sha512", do_sha512, GetOpt::NO_ARG);
+       getopt.add_argument("file", files, GetOpt::REQUIRED_ARG);
+       getopt(argc, argv);
+
+       if(!do_md5 && !do_sha256 && !do_sha512)
+               do_md5 = true;
+}
+
+int Checksum::main()
+{
+       for(list<string>::const_iterator i=files.begin(); i!=files.end(); ++i)
+       {
+               if(do_md5)
+                       process_file<Crypto::MD5>(*i);
+               if(do_sha256)
+                       process_file<Crypto::SHA256>(*i);
+               if(do_sha512)
+                       process_file<Crypto::SHA512>(*i);
+       }
+       return 0;
+}
+
+template<typename H>
+void Checksum::process_file(const string &fn)
+{
+       IO::BufferedFile infile(fn);
+       H hash;
+       while(1)
+       {
+               char buffer[16384];
+               unsigned len = infile.read(buffer, sizeof(buffer));
+               if(!len)
+                       break;
+               hash.update(buffer, len);
+       }
+       IO::print("%s  %s\n", hash.get_hexdigest(), fn);
+}