data: add shortcuts to access SignatureType and KeyLocator

Also, modernize the API of SignatureInfo and deprecate
unsetKeyLocator() and unsetValidityPeriod()

Change-Id: I8b775a4deb185784a3dcc8bd96c8f5f0c2915854
diff --git a/tests/unit/security/v2/certificate.t.cpp b/tests/unit/security/v2/certificate.t.cpp
index dc1d8b5..0d848fd 100644
--- a/tests/unit/security/v2/certificate.t.cpp
+++ b/tests/unit/security/v2/certificate.t.cpp
@@ -63,17 +63,14 @@
 };
 
 const uint8_t SIG_VALUE[] = {
-  0x17, 0x80, // SignatureValue
-    0x2f, 0xd6, 0xf1, 0x6e, 0x80, 0x6f, 0x10, 0xbe, 0xb1, 0x6f, 0x3e, 0x31, 0xec,
-    0xe3, 0xb9, 0xea, 0x83, 0x30, 0x40, 0x03, 0xfc, 0xa0, 0x13, 0xd9, 0xb3, 0xc6,
-    0x25, 0x16, 0x2d, 0xa6, 0x58, 0x41, 0x69, 0x62, 0x56, 0xd8, 0xb3, 0x6a, 0x38,
-    0x76, 0x56, 0xea, 0x61, 0xb2, 0x32, 0x70, 0x1c, 0xb6, 0x4d, 0x10, 0x1d, 0xdc,
-    0x92, 0x8e, 0x52, 0xa5, 0x8a, 0x1d, 0xd9, 0x96, 0x5e, 0xc0, 0x62, 0x0b, 0xcf,
-    0x3a, 0x9d, 0x7f, 0xca, 0xbe, 0xa1, 0x41, 0x71, 0x85, 0x7a, 0x8b, 0x5d, 0xa9,
-    0x64, 0xd6, 0x66, 0xb4, 0xe9, 0x8d, 0x0c, 0x28, 0x43, 0xee, 0xa6, 0x64, 0xe8,
-    0x55, 0xf6, 0x1c, 0x19, 0x0b, 0xef, 0x99, 0x25, 0x1e, 0xdc, 0x78, 0xb3, 0xa7,
-    0xaa, 0x0d, 0x14, 0x58, 0x30, 0xe5, 0x37, 0x6a, 0x6d, 0xdb, 0x56, 0xac, 0xa3,
-    0xfc, 0x90, 0x7a, 0xb8, 0x66, 0x9c, 0x0e, 0xf6, 0xb7, 0x64, 0xd1
+  0x2f, 0xd6, 0xf1, 0x6e, 0x80, 0x6f, 0x10, 0xbe, 0xb1, 0x6f, 0x3e, 0x31, 0xec, 0xe3, 0xb9, 0xea,
+  0x83, 0x30, 0x40, 0x03, 0xfc, 0xa0, 0x13, 0xd9, 0xb3, 0xc6, 0x25, 0x16, 0x2d, 0xa6, 0x58, 0x41,
+  0x69, 0x62, 0x56, 0xd8, 0xb3, 0x6a, 0x38, 0x76, 0x56, 0xea, 0x61, 0xb2, 0x32, 0x70, 0x1c, 0xb6,
+  0x4d, 0x10, 0x1d, 0xdc, 0x92, 0x8e, 0x52, 0xa5, 0x8a, 0x1d, 0xd9, 0x96, 0x5e, 0xc0, 0x62, 0x0b,
+  0xcf, 0x3a, 0x9d, 0x7f, 0xca, 0xbe, 0xa1, 0x41, 0x71, 0x85, 0x7a, 0x8b, 0x5d, 0xa9, 0x64, 0xd6,
+  0x66, 0xb4, 0xe9, 0x8d, 0x0c, 0x28, 0x43, 0xee, 0xa6, 0x64, 0xe8, 0x55, 0xf6, 0x1c, 0x19, 0x0b,
+  0xef, 0x99, 0x25, 0x1e, 0xdc, 0x78, 0xb3, 0xa7, 0xaa, 0x0d, 0x14, 0x58, 0x30, 0xe5, 0x37, 0x6a,
+  0x6d, 0xdb, 0x56, 0xac, 0xa3, 0xfc, 0x90, 0x7a, 0xb8, 0x66, 0x9c, 0x0e, 0xf6, 0xb7, 0x64, 0xd1,
 };
 
 const uint8_t CERT[] = {
@@ -136,7 +133,7 @@
                                                  time::fromIsoString("20141111T060000")));
 
   data.setSignatureInfo(signatureInfo);
-  data.setSignatureValue(Block(SIG_VALUE, sizeof(SIG_VALUE)));
+  data.setSignatureValue(make_shared<Buffer>(SIG_VALUE, sizeof(SIG_VALUE)));
 }
 
 BOOST_AUTO_TEST_CASE(Construction)
@@ -149,8 +146,10 @@
   BOOST_CHECK_EQUAL(certificate.getIdentity(), "/ndn/site1");
   BOOST_CHECK_EQUAL(certificate.getIssuerId(), name::Component("0123"));
   BOOST_CHECK_EQUAL(certificate.getKeyId(), name::Component("ksk-1416425377094"));
-  BOOST_CHECK_EQUAL(certificate.getSignatureInfo().getKeyLocator().getName(), "/ndn/site1/KEY/ksk-2516425377094");
-  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(certificate.getValidityPeriod()), "(20150814T223739, 20150818T223738)");
+  BOOST_REQUIRE_EQUAL(certificate.getKeyLocator().has_value(), true);
+  BOOST_CHECK_EQUAL(certificate.getKeyLocator()->getName(), "/ndn/site1/KEY/ksk-2516425377094");
+  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(certificate.getValidityPeriod()),
+                    "(20150814T223739, 20150818T223738)");
 
   BOOST_CHECK_THROW(certificate.getExtension(12345), ndn::SignatureInfo::Error);
   BOOST_CHECK_NO_THROW(certificate.getPublicKey());
@@ -173,8 +172,10 @@
   BOOST_CHECK_EQUAL(certificate.getIdentity(), "/ndn/site1");
   BOOST_CHECK_EQUAL(certificate.getIssuerId(), name::Component("0123"));
   BOOST_CHECK_EQUAL(certificate.getKeyId(), name::Component("ksk-1416425377094"));
-  BOOST_CHECK_EQUAL(certificate.getSignatureInfo().getKeyLocator().getName(), "/ndn/site1/KEY/ksk-2516425377094");
-  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(certificate.getValidityPeriod()), "(20141111T050000, 20141111T060000)");
+  BOOST_REQUIRE_EQUAL(certificate.getKeyLocator().has_value(), true);
+  BOOST_CHECK_EQUAL(certificate.getKeyLocator()->getName(), "/ndn/site1/KEY/ksk-2516425377094");
+  BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(certificate.getValidityPeriod()),
+                    "(20141111T050000, 20141111T060000)");
 
   BOOST_CHECK_THROW(certificate.getExtension(12345), ndn::SignatureInfo::Error);
   BOOST_CHECK_NO_THROW(certificate.getPublicKey());