initial code repo

[stor4nfv.git] / src / ceph / src / rgw / rgw_b64.h

diff --git a/src/ceph/src/rgw/rgw_b64.h b/src/ceph/src/rgw/rgw_b64.h
new file mode 100644 (file)
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+++ b/src/ceph/src/rgw/rgw_b64.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef RGW_B64_H
+#define RGW_B64_H
+
+#include <boost/utility/string_ref.hpp>
+#include <boost/utility/string_view.hpp>
+#include <boost/archive/iterators/base64_from_binary.hpp>
+#include <boost/archive/iterators/binary_from_base64.hpp>
+#include <boost/archive/iterators/insert_linebreaks.hpp>
+#include <boost/archive/iterators/transform_width.hpp>
+#include <boost/archive/iterators/remove_whitespace.hpp>
+#include <limits>
+
+namespace rgw {
+
+  /*
+   * A header-only Base64 encoder built on boost::archive.  The
+   * formula is based on a class poposed for inclusion in boost in
+   * 2011 by Denis Shevchenko (abandoned), updated slightly
+   * (e.g., uses boost::string_view).
+   *
+   * Also, wrap_width added as template argument, based on
+   * feedback from Marcus.
+   */
+
+  template<int wrap_width = std::numeric_limits<int>::max()>
+  inline std::string to_base64(boost::string_view sview)
+  {
+    using namespace boost::archive::iterators;
+
+    // output must be =padded modulo 3
+    auto psize = sview.size();
+    while ((psize % 3) != 0) {
+      ++psize;
+    }
+
+    /* RFC 2045 requires linebreaks to be present in the output
+     * sequence every at-most 76 characters (MIME-compliance),
+     * but we could likely omit it. */
+    typedef
+      insert_linebreaks<
+        base64_from_binary<
+          transform_width<
+           boost::string_view::const_iterator
+            ,6,8>
+          >
+          ,wrap_width
+        > b64_iter;
+
+    std::string outstr(b64_iter(sview.data()),
+                      b64_iter(sview.data() + sview.size()));
+
+    // pad outstr with '=' to a length that is a multiple of 3
+    for (size_t ix = 0; ix < (psize-sview.size()); ++ix)
+      outstr.push_back('=');
+
+    return outstr;
+  }
+
+  inline std::string from_base64(boost::string_view sview)
+  {
+    using namespace boost::archive::iterators;
+    if (sview.empty())
+      return std::string();
+    /* MIME-compliant input will have line-breaks, so we have to
+     * filter WS */
+    typedef
+      transform_width<
+      binary_from_base64<
+       remove_whitespace<
+         boost::string_view::const_iterator>>
+      ,8,6
+      > b64_iter;
+
+    while (sview.back() == '=')
+      sview.remove_suffix(1);
+
+    std::string outstr(b64_iter(sview.data()),
+                     b64_iter(sview.data() + sview.size()));
+
+    return outstr;
+  }
+} /* namespace */
+
+#endif /* RGW_B64_H */