security: Add base64 and hex encoding/decoding support in transformation
Change-Id: I11d5c8921abcf04411aac38382dc285269f553ef
Refs: #3009
diff --git a/src/security/transform/base64-decode.cpp b/src/security/transform/base64-decode.cpp
new file mode 100644
index 0000000..7f3cf54
--- /dev/null
+++ b/src/security/transform/base64-decode.cpp
@@ -0,0 +1,135 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "base64-decode.hpp"
+#include "../../encoding/buffer.hpp"
+#include "../detail/openssl.hpp"
+
+namespace ndn {
+namespace security {
+namespace transform {
+
+/**
+ * @brief The implementation class which contains the internal state of the filter
+ * which includes openssl specific structures.
+ */
+class Base64Decode::Impl
+{
+public:
+ Impl()
+ : m_base64(BIO_new(BIO_f_base64()))
+ , m_source(BIO_new(BIO_s_mem()))
+ {
+ // Input may not be written in a single time.
+ // Do not return EOF when source is empty unless explicitly requested
+ BIO_set_mem_eof_return(m_source, -1);
+
+ // connect base64 transform to the data source.
+ BIO_push(m_base64, m_source);
+ }
+
+ ~Impl()
+ {
+ BIO_free_all(m_source);
+ }
+
+public:
+ BIO* m_base64;
+ BIO* m_source; // BIO_f_base64 alone does not work without a source
+};
+
+static const size_t BUFFER_LENGTH = 1024;
+
+Base64Decode::Base64Decode(bool expectNewlineEvery64Bytes)
+ : m_impl(new Impl)
+{
+ if (!expectNewlineEvery64Bytes)
+ BIO_set_flags(m_impl->m_base64, BIO_FLAGS_BASE64_NO_NL);
+}
+
+void
+Base64Decode::preTransform()
+{
+ while (isOutputBufferEmpty()) {
+ fillOutputBuffer();
+ if (isOutputBufferEmpty()) // nothing to read from BIO, return
+ return;
+
+ flushOutputBuffer();
+ }
+}
+
+size_t
+Base64Decode::convert(const uint8_t* buf, size_t size)
+{
+ int wLen = BIO_write(m_impl->m_source, buf, size);
+
+ if (wLen <= 0) { // fail to write data
+ if (!BIO_should_retry(m_impl->m_source)) {
+ // we haven't written everything but some error happens, and we cannot retry
+ BOOST_THROW_EXCEPTION(Error(getIndex(), "Failed to accept more input"));
+ }
+ return 0;
+ }
+ else { // update number of bytes written
+ return wLen;
+ }
+}
+
+void
+Base64Decode::finalize()
+{
+ BIO_set_mem_eof_return(m_impl->m_source, 0);
+
+ fillOutputBuffer();
+
+ while (!isOutputBufferEmpty()) {
+ flushOutputBuffer();
+ if (isOutputBufferEmpty())
+ fillOutputBuffer();
+ }
+}
+
+void
+Base64Decode::fillOutputBuffer()
+{
+ // OpenSSL base64 BIO cannot give us the number bytes of partial decoded result,
+ // so we just try to read a chunk.
+ auto buffer = make_unique<OBuffer>(BUFFER_LENGTH);
+ int rLen = BIO_read(m_impl->m_base64, &(*buffer)[0], buffer->size());
+ if (rLen <= 0)
+ return;
+
+ if (static_cast<size_t>(rLen) < buffer->size())
+ buffer->erase(buffer->begin() + rLen, buffer->end());
+
+ setOutputBuffer(std::move(buffer));
+}
+
+unique_ptr<Transform>
+base64Decode(bool expectNewlineEvery64Bytes)
+{
+ return make_unique<Base64Decode>(expectNewlineEvery64Bytes);
+}
+
+} // namespace transform
+} // namespace security
+} // namespace ndn