From d599dd9a681d815dd6627b358ee36b5a6354f6c0 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 16 Apr 2016 16:51:46 +0300
Subject: [PATCH] Add an example program demonstrating hash API

Also useful for verifying the implementations.
---
 .gitignore            |  1 +
 Build                 |  6 ++++
 examples/checksum.cpp | 75 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 82 insertions(+)
 create mode 100644 examples/checksum.cpp

diff --git a/.gitignore b/.gitignore
index 536c16b..87f978a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 .config
 temp
+/checksum
 /libmspcrypto.a
 /libmspcrypto.so
 /mspcrypto.pc
diff --git a/Build b/Build
index 003e9e3..9b96d9e 100644
--- a/Build
+++ b/Build
@@ -14,4 +14,10 @@ package "mspcrypto"
 			map "source" "include/msp/crypto";
 		};
 	};
+
+	program "checksum"
+	{
+		source "examples/checksum.cpp";
+		use "mspcrypto";
+	};
 };
diff --git a/examples/checksum.cpp b/examples/checksum.cpp
new file mode 100644
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);
+}
-- 
2.43.0