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Yingdi Yu38317e52015-07-22 13:58:02 -07001/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2/**
3 * Copyright (c) 2013-2016 Regents of the University of California.
4 *
5 * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
6 *
7 * ndn-cxx library is free software: you can redistribute it and/or modify it under the
8 * terms of the GNU Lesser General Public License as published by the Free Software
9 * Foundation, either version 3 of the License, or (at your option) any later version.
10 *
11 * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
12 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
14 *
15 * You should have received copies of the GNU General Public License and GNU Lesser
16 * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
17 * <http://www.gnu.org/licenses/>.
18 *
19 * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
20 */
21
22#include "base64-decode.hpp"
23#include "../../encoding/buffer.hpp"
24#include "../detail/openssl.hpp"
25
26namespace ndn {
27namespace security {
28namespace transform {
29
30/**
31 * @brief The implementation class which contains the internal state of the filter
32 * which includes openssl specific structures.
33 */
34class Base64Decode::Impl
35{
36public:
37 Impl()
38 : m_base64(BIO_new(BIO_f_base64()))
39 , m_source(BIO_new(BIO_s_mem()))
40 {
41 // Input may not be written in a single time.
42 // Do not return EOF when source is empty unless explicitly requested
43 BIO_set_mem_eof_return(m_source, -1);
44
45 // connect base64 transform to the data source.
46 BIO_push(m_base64, m_source);
47 }
48
49 ~Impl()
50 {
51 BIO_free_all(m_source);
52 }
53
54public:
55 BIO* m_base64;
56 BIO* m_source; // BIO_f_base64 alone does not work without a source
57};
58
59static const size_t BUFFER_LENGTH = 1024;
60
61Base64Decode::Base64Decode(bool expectNewlineEvery64Bytes)
62 : m_impl(new Impl)
63{
64 if (!expectNewlineEvery64Bytes)
65 BIO_set_flags(m_impl->m_base64, BIO_FLAGS_BASE64_NO_NL);
66}
67
68void
69Base64Decode::preTransform()
70{
71 while (isOutputBufferEmpty()) {
72 fillOutputBuffer();
73 if (isOutputBufferEmpty()) // nothing to read from BIO, return
74 return;
75
76 flushOutputBuffer();
77 }
78}
79
80size_t
81Base64Decode::convert(const uint8_t* buf, size_t size)
82{
83 int wLen = BIO_write(m_impl->m_source, buf, size);
84
85 if (wLen <= 0) { // fail to write data
86 if (!BIO_should_retry(m_impl->m_source)) {
87 // we haven't written everything but some error happens, and we cannot retry
88 BOOST_THROW_EXCEPTION(Error(getIndex(), "Failed to accept more input"));
89 }
90 return 0;
91 }
92 else { // update number of bytes written
93 return wLen;
94 }
95}
96
97void
98Base64Decode::finalize()
99{
100 BIO_set_mem_eof_return(m_impl->m_source, 0);
101
102 fillOutputBuffer();
103
104 while (!isOutputBufferEmpty()) {
105 flushOutputBuffer();
106 if (isOutputBufferEmpty())
107 fillOutputBuffer();
108 }
109}
110
111void
112Base64Decode::fillOutputBuffer()
113{
114 // OpenSSL base64 BIO cannot give us the number bytes of partial decoded result,
115 // so we just try to read a chunk.
116 auto buffer = make_unique<OBuffer>(BUFFER_LENGTH);
117 int rLen = BIO_read(m_impl->m_base64, &(*buffer)[0], buffer->size());
118 if (rLen <= 0)
119 return;
120
121 if (static_cast<size_t>(rLen) < buffer->size())
122 buffer->erase(buffer->begin() + rLen, buffer->end());
123
124 setOutputBuffer(std::move(buffer));
125}
126
127unique_ptr<Transform>
128base64Decode(bool expectNewlineEvery64Bytes)
129{
130 return make_unique<Base64Decode>(expectNewlineEvery64Bytes);
131}
132
133} // namespace transform
134} // namespace security
135} // namespace ndn