Add SHA256 calculator

Based on the sha256c.c file from the FreeBSD project and ported to compile on
Linux, Mac OS, and Windows. The file is licensed under the simplified/2-clause
BSD license so the library is now MIT/BSD-licensed.

3 files changed, 42 insertions, 1 deletions

diff --git a/tests/buildfile b/tests/buildfile
index 57e632e..0ad40e5 100644
--- a/tests/buildfile
+++ b/tests/buildfile
@@ -2,6 +2,6 @@
 # copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
 # license   : MIT; see accompanying LICENSE file
 
-d = dir-iterator/ path/ prefix-map/ triplet/
+d = dir-iterator/ path/ prefix-map/ sha256/ triplet/
 .: $d
 include $d
diff --git a/tests/sha256/buildfile b/tests/sha256/buildfile
new file mode 100644
index 0000000..4116ff6
--- /dev/null
+++ b/tests/sha256/buildfile
@@ -0,0 +1,7 @@
+# file      : tests/sha256/buildfile
+# copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
+# license   : MIT; see accompanying LICENSE file
+
+exe{driver}: cxx{driver} ../../butl/lib{butl}
+
+include ../../butl/
diff --git a/tests/sha256/driver.cxx b/tests/sha256/driver.cxx
new file mode 100644
index 0000000..12928b2
--- /dev/null
+++ b/tests/sha256/driver.cxx
@@ -0,0 +1,34 @@
+// file      : tests/triplet/driver.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <string>
+#include <cassert>
+#include <iostream>
+
+#include <butl/sha256>
+
+using namespace std;
+using namespace butl;
+
+int
+main ()
+{
+  assert (string (sha256 ().string ()) ==
+          "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855");
+
+  assert (string (sha256 ("123").string ()) ==
+          "a665a45920422f9d417e4867efdc4fb8a04a1f3fff1fa07e998e86f7f7a27ae3");
+
+  sha256 h;
+  h.append ("1");
+  h.append (string ("2"));
+  h.append ("3", 1);
+
+  auto& b (h.binary ());
+  assert (b[0] == 0xa6 && b[31] == 0xe3);
+
+  string s (h.string ());
+  assert (s ==
+          "a665a45920422f9d417e4867efdc4fb8a04a1f3fff1fa07e998e86f7f7a27ae3");
+}