Add BuildVersion and RuntimeVersion functions (Issue 371)

These function are intended to catch mining and matching of library versions. BuildVersion provides CRYPTOPP_VERSION when the shared object was built. RuntimeVersion provides CRYPTOPP_VERSION the app compiled against, which could be different than the shared object's version

cryptlib.cpp

@@ -313,7 +313,7 @@ word32 RandomNumberGenerator::GenerateWord32(word32 min, word32 max)
 
 // Stack recursion below... GenerateIntoBufferedTransformation calls GenerateBlock,
 // and GenerateBlock calls GenerateIntoBufferedTransformation. Ad infinitum. Also
-// see https://github.com/weidai11/cryptopp/issues/38.
+// see http://github.com/weidai11/cryptopp/issues/38.
 //
 // According to Wei, RandomNumberGenerator is an interface, and it should not
 // be instantiable. Its now spilt milk, and we are going to CRYPTOPP_ASSERT it in Debug
@@ -945,6 +945,15 @@ void AuthenticatedKeyAgreementDomain::GenerateEphemeralKeyPair(RandomNumberGener
 	GenerateEphemeralPublicKey(rng, privateKey, publicKey);
 }
 
+// Allow a distro or packager to override the build-time version
+//  http://github.com/weidai11/cryptopp/issues/371
+#ifndef CRYPTOPP_BUILD_VERSION
+# define CRYPTOPP_BUILD_VERSION CRYPTOPP_VERSION
+#endif
+int BuildVersion()
+{
+	return CRYPTOPP_BUILD_VERSION;
+}
 NAMESPACE_END
 
 #endif

cryptlib.h

@@ -2914,6 +2914,76 @@ public:
 	virtual void BEREncode(BufferedTransformation &bt) const {DEREncode(bt);}
 };
 
+//! \brief Specifies the build-time version of the library
+//! \returns integer representing the build-time version
+//! \details BuildVersion can help detect inadvertent mixing and matching of library
+//!   versions. When using Crypto++ distributed by a third party, BuildVersion()
+//!   records the version of the shared object that was built by the third party.
+//!   The BuildVersion() record resides in <tt>cryptlib.o</tt> on Unix compatibles
+//!   and <tt>cryptlib.obj</tt> on Windows. It does not change when an app links
+//!   to the library.
+//! \details BuildVersion() is declared with C linkage (<tt>extern "C"</tt>) within the
+//!   CryptoPP namespace to help programs locate the symbol. If the symbol is present, then
+//!   the library version is 5.7 or above. If it is missing, then the library version is
+//!   5.6.5 or below.
+//! \details The function could be used as shown below.
+//! <pre>
+//!     if (BuildVersion() != RuntimeVersion())
+//!     {
+//!         cout << "Potential version mismatch" << endl;
+//!
+//!         const int bmaj = (BuildVersion() / 100U) % 10;
+//!         const int bmin = (BuildVersion() / 10U) % 10;
+//!         const int rmaj = (RuntimeVersion() / 100U) % 10;
+//!         const int rmin = (RuntimeVersion() / 10U) % 10;
+//!
+//!         if(bmaj != rmaj)
+//!             cout << "Major version mismatch" << endl;
+//!         else if(bmin != rmin)
+//!             cout << "Minor version mismatch" << endl;
+//!      }
+//! </pre>
+//! \sa RuntimeVersion(), <A HREF="http://github.com/weidai11/cryptopp/issues/371">GitHub Issue 371</A>.
+//! \since Crypto++ 5.7
+extern "C" {
+	int BuildVersion();
+} // C linkage
+
+//! \brief Specifies the runtime version of the library
+//! \returns integer representing the runtime version
+//! \details RuntimeVersion() can help detect inadvertent mixing and matching of library
+//!   versions. When using Crypto++ distributed by a third party, RuntimeVersion()
+//!   records the version of the headers used by the app when the app is compiled.
+//! \details RuntimeVersion() is declared with C linkage (<tt>extern "C"</tt>) within the
+//!   CryptoPP namespace to help programs locate the symbol. If the symbol is present, then
+//!   the library version is 5.7 or above. If it is missing, then the library version is
+//!   5.6.5 or below.
+//! \details The function could be used as shown below.
+//! <pre>
+//!     if (BuildVersion() != RuntimeVersion())
+//!     {
+//!         cout << "Potential version mismatch" << endl;
+//!
+//!         const int bmaj = (BuildVersion() / 100U) % 10;
+//!         const int bmin = (BuildVersion() / 10U) % 10;
+//!         const int rmaj = (RuntimeVersion() / 100U) % 10;
+//!         const int rmin = (RuntimeVersion() / 10U) % 10;
+//!
+//!         if(bmaj != rmaj)
+//!             cout << "Major version mismatch" << endl;
+//!         else if(bmin != rmin)
+//!             cout << "Minor version mismatch" << endl;
+//!      }
+//! </pre>
+//! \sa BuildVersion(), <A HREF="http://github.com/weidai11/cryptopp/issues/371">GitHub Issue 371</A>.
+//! \since Crypto++ 5.7
+extern "C" {
+inline int RuntimeVersion()
+{
+	return CRYPTOPP_VERSION;
+}
+} // C linkage
+
 NAMESPACE_END
 
 #if CRYPTOPP_MSC_VERSION

gfpcrypt.h

@@ -399,7 +399,7 @@ private:
 //! \tparam T FieldElement type or class
 //! \details The Digital Signature Scheme ECGDSA does not define the algorithm over integers. Rather, the
 //!   signature algorithm is only defined over elliptic curves. However, The library design is such that the
-//!   generic algorithm reside in \header gfpcrypt.h.
+//!   generic algorithm reside in <tt>gfpcrypt.h</tt>.
 //! \sa Erwin Hess, Marcus Schafheutle, and Pascale Serf <A HREF="http://www.teletrust.de/fileadmin/files/oid/ecgdsa_final.pdf">
 //!   The Digital Signature Scheme ECGDSA (October 24, 2006)</A>
 template <class T>

validat1.cpp

@@ -225,6 +225,18 @@ bool TestSettings()
 		pass = false;
 	}
 
+	// App and library versions, http://github.com/weidai11/cryptopp/issues/371
+	const int bver = BuildVersion();
+	const int rver = RuntimeVersion();
+	if(bver/10 == rver/10)
+		cout << "passed:  ";
+	else
+	{
+		cout << "FAILED:  ";
+		pass = false;
+	}
+	cout << "Build version (library): " << bver << ", runtime version (app): " << rver << "\n";
+
 #ifdef CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS
 	// Don't assert the alignment of testvals. That's what this test is for.
 	byte testvals[10] = {1,2,2,3,3,3,3,2,2,1};