signature: disallow encoding invalid SignatureInfo

Also, check integer range when decoding SignatureInfo.

refs #3200

Change-Id: I1af4833211c9468ac7ecab48f7d0e88e9423b378
diff --git a/tests/unit-tests/signature-info.t.cpp b/tests/unit-tests/signature-info.t.cpp
index 1945841..828bcf8 100644
--- a/tests/unit-tests/signature-info.t.cpp
+++ b/tests/unit-tests/signature-info.t.cpp
@@ -1,5 +1,5 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
+/*
  * Copyright (c) 2013-2017 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
@@ -231,26 +231,23 @@
 
 BOOST_AUTO_TEST_CASE(OtherTlvsEncoding) // Bug #3914
 {
-  SignatureInfo info1;
+  SignatureInfo info1(tlv::SignatureSha256WithRsa);
   info1.appendTypeSpecificTlv(makeStringBlock(101, "First"));
   info1.appendTypeSpecificTlv(makeStringBlock(102, "Second"));
   info1.appendTypeSpecificTlv(makeStringBlock(103, "Third"));
 
-  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(info1), "Unknown Signature Type { 101 102 103 }");
+  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(info1), "SignatureSha256WithRsa { 101 102 103 }");
 
   SignatureInfo info2;
   info2.wireDecode(info1.wireEncode());
   BOOST_CHECK_EQUAL(info1, info2);
 
-  // // These octets are obtained by the snippet below.
-  // // This check is intended to detect unexpected encoding change in the future.
-  // for (uint8_t ch : info1.wireEncode()) {
-  //  printf("0x%02x, ", ch);
-  // }
   const uint8_t infoBytes[] = {
-    0x16, 0x20, 0x1b, 0x08, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x65, 0x05, 0x46, 0x69,
-    0x72, 0x73, 0x74, 0x66, 0x06, 0x53, 0x65, 0x63, 0x6f, 0x6e, 0x64, 0x67, 0x05, 0x54, 0x68, 0x69,
-    0x72, 0x64
+    0x16, 0x19, // SignatureInfo
+          0x1b, 0x01, 0x01, // SignatureType=1
+          0x65, 0x05, 0x46, 0x69, 0x72, 0x73, 0x74, // 101 "First"
+          0x66, 0x06, 0x53, 0x65, 0x63, 0x6f, 0x6e, 0x64, // 102 "Second"
+          0x67, 0x05, 0x54, 0x68, 0x69, 0x72, 0x64 // 103 "Third"
   };
 
   SignatureInfo info3(Block(infoBytes, sizeof(infoBytes)));