security: CryptoPP functions are used directly to encode/decode DER/BER
This change eliminates the need for custom der decoder/encoder.
Change-Id: I5be2e55cec2b63157927a4ad87fffe8e8651ed3c
diff --git a/src/encoding/cryptopp/asn_ext.cpp b/src/encoding/cryptopp/asn_ext.cpp
new file mode 100644
index 0000000..6698426
--- /dev/null
+++ b/src/encoding/cryptopp/asn_ext.cpp
@@ -0,0 +1,107 @@
+/**
+ * Copyright (C) 2013 Regents of the University of California.
+ * @author: Jeff Thompson <jefft0@remap.ucla.edu>
+ * @author: Yingdi Yu <yingdi@cs.ucla.edu>
+ * @author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ * See COPYING for copyright and distribution information.
+ */
+
+#include <ndn-cpp/ndn-cpp-config.h>
+#include "asn_ext.hpp"
+
+#if NDN_CPP_HAVE_TIME_H
+#include <time.h>
+#endif
+#if NDN_CPP_HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+
+#include <boost/format.hpp>
+#include <boost/lexical_cast.hpp>
+
+using namespace CryptoPP;
+
+namespace ndn {
+
+size_t
+DEREncodeGeneralTime(CryptoPP::BufferedTransformation &bt, MillisecondsSince1970 time)
+{
+#ifndef NDN_CPP_HAVE_GMTIME_SUPPORT
+ throw Asn::Error("Time functions are not supported by the standard library");
+#endif
+
+ if (time < 0)
+ throw Asn::Error("Calendar time value out of range");
+ else if (time > 2e14)
+ // 2e14 is about the year 8300. We don't want to go over a 4-digit year.
+ throw Asn::Error("Calendar time value out of range");
+
+ time_t secondsSince1970 = time / 1000;
+ struct tm* gmt = gmtime(&secondsSince1970);
+
+ std::string asn1time ((boost::format("%04d%02d%02d%02d%02d%02d%sZ")
+ % (1900 + gmt->tm_year)
+ % (gmt->tm_mon + 1)
+ % gmt->tm_mday
+ % gmt->tm_hour
+ % gmt->tm_min
+ % gmt->tm_sec).str());
+ // = os.str();
+
+ bt.Put(GENERALIZED_TIME);
+ size_t lengthBytes = DERLengthEncode(bt, asn1time.size());
+ bt.Put(reinterpret_cast<const uint8_t*>(asn1time.c_str()), asn1time.size());
+ return 1+lengthBytes+asn1time.size();
+}
+
+void
+BERDecodeTime(CryptoPP::BufferedTransformation &bt, MillisecondsSince1970 &time)
+{
+ byte b;
+ if (!bt.Get(b) || (b != GENERALIZED_TIME && b != UTC_TIME))
+ BERDecodeError();
+
+ size_t bc;
+ if (!BERLengthDecode(bt, bc))
+ BERDecodeError();
+
+ SecByteBlock time_str(bc);
+ if (bc != bt.Get(time_str, bc))
+ BERDecodeError();
+
+ std::vector<std::string> params;
+ std::string current;
+ std::locale cLocale("C");
+
+ for(uint32_t j = 0; j != time_str.size(); ++j)
+ {
+ if(std::isdigit(reinterpret_cast<char&>(time_str[j]), cLocale))
+ current += time_str[j];
+ else
+ {
+ if(current != "")
+ params.push_back(current);
+ current.clear();
+ }
+ }
+ if(current != "")
+ params.push_back(current);
+
+ if(params.size() < 3 || params.size() > 6)
+ throw Asn::Error("Invalid time specification " + std::string(time_str.begin(), time_str.end()));
+
+ struct tm gmt;
+ gmt.tm_year = boost::lexical_cast<int>(params[0]);
+ gmt.tm_mon = boost::lexical_cast<int>(params[1]) - 1;
+ gmt.tm_mday = boost::lexical_cast<int>(params[2]);
+ gmt.tm_hour = (params.size() >= 4) ? boost::lexical_cast<int>(params[3]) : 0;
+ gmt.tm_min = (params.size() >= 5) ? boost::lexical_cast<int>(params[4]) : 0;
+ gmt.tm_sec = (params.size() == 6) ? boost::lexical_cast<int>(params[5]) : 0;
+
+ if (b == GENERALIZED_TIME)
+ gmt.tm_year -= 1900;
+
+ time = timegm(&gmt) * 1000;
+}
+
+} // namespace ndn