From 9484815960fc29305b1d1a62607e001b4df8b327 Mon Sep 17 00:00:00 2001
From: Jeffrey Walton <noloader@gmail.com>
Date: Wed, 2 Jan 2019 03:30:49 -0500
Subject: [PATCH] Cache DataDir when C++11 dynamic init is available (GH #760)

---
 test.cpp   | 11 +++++++++
 validate.h | 66 +++++++++++++++++++++++++++++++++++-------------------
 2 files changed, 54 insertions(+), 23 deletions(-)

diff --git a/test.cpp b/test.cpp
index 843342b6..3f5d1ee1 100644
--- a/test.cpp
+++ b/test.cpp
@@ -75,6 +75,7 @@ NAMESPACE_BEGIN(CryptoPP)
 NAMESPACE_BEGIN(Test)
 
 const int MAX_PHRASE_LENGTH=250;
+std::string g_argvPathHint="";
 
 void GenerateRSAKey(unsigned int keyLength, const char *privFilename, const char *pubFilename, const char *seed);
 std::string RSAEncryptString(const char *pubFilename, const char *seed, const char *message);
@@ -149,6 +150,16 @@ int scoped_main(int argc, char *argv[])
 	cin.set_safe_flag(stream_MT::unsafe_object);
 #endif
 
+	// A hint to help locate TestData/ and TestVectors/ after install.
+	g_argvPathHint = argc > 0 ? argv[0] : "";
+#if defined(AT_EXECFN)
+	if (getauxval(AT_EXECFN))
+		g_argvPathHint = getauxval(AT_EXECFN);
+#endif
+	std::string::size_type pos = g_argvPathHint.find_last_of("\\/");
+	if (pos != std::string::npos)
+		g_argvPathHint.erase(pos+1);
+
 	try
 	{
 		RegisterFactories(All);
diff --git a/validate.h b/validate.h
index d4f78997..d49a8dea 100644
--- a/validate.h
+++ b/validate.h
@@ -20,6 +20,12 @@
 NAMESPACE_BEGIN(CryptoPP)
 NAMESPACE_BEGIN(Test)
 
+// A hint to help locate TestData/ and TestVectors/ after install. Due to
+// execve the path can be malicious. If the path is ficticous then we move
+// onto the next potential path. Also note we only read from the path; we
+// never write through it. Storage for the string is in test.cpp.
+extern std::string g_argvPathHint;
+
 bool ValidateAll(bool thorough);
 bool TestSettings();
 bool TestOS_RNG();
@@ -205,10 +211,10 @@ inline std::string TimeToString(const time_t& t)
 
 	// Cleanup whitespace
 	std::string::size_type pos = 0;
-	while (!str.empty() && std::isspace(*(str.end()-1)))
+	while (!str.empty() && std::isspace(str[str.length()-1]))
 		{str.erase(str.end()-1);}
 	while (!str.empty() && std::string::npos != (pos = str.find("  ", pos)))
-		{ str.erase(pos, 1); }
+		{str.erase(pos, 1);}
 
 	return str;
 }
@@ -252,46 +258,60 @@ inline int StringToValue<int, true>(const std::string& str)
 
 inline std::string AddSeparator(std::string str)
 {
-	const char last = (str.empty() ? '\0' : *str.end()-1);
+	const char last = (str.empty() ? '\0' : str[str.length()-1]);
 	if (last != '/' && last != '\\')
 		return str + "/";
 	return str;
 }
 
-// Ideally we would cache the directory and just add the prefix
-// to subsequent calls, but ... Static Initialization Order Fiasco
+static std::string GetDataDir()
+{
+	std::ifstream file;
+	std::string name, filename = "TestData/usage.dat";
+
+#ifndef CRYPTOPP_DISABLE_DATA_DIR_SEARCH
+	name = AddSeparator(g_argvPathHint) + filename;
+	file.open(name.c_str());
+	if (file.is_open())
+		return AddSeparator(g_argvPathHint);
+#endif
+#ifndef CRYPTOPP_DISABLE_DATA_DIR_SEARCH
+	// Look in $ORIGIN/../share/. This is likely a Linux install directory.
+	name = AddSeparator(g_argvPathHint) + std::string("../share/cryptopp/") + filename;
+	file.open(name.c_str());
+	if (file.is_open())
+		return AddSeparator(g_argvPathHint) + std::string("../share/cryptopp/");
+#endif
+	return "./";
+}
+
 inline std::string DataDir(const std::string& filename)
 {
 	std::string name;
 	std::ifstream file;
-#ifndef CRYPTOPP_DISABLE_DATA_DIR_SEARCH
-	// Data files in PWD are probably the newest. This is probably a build directory.
-	name = std::string("./") + filename;
-	file.open(name.c_str());
-	if (file.is_open())
-		return name;
-#endif
+
 #ifdef CRYPTOPP_DATA_DIR
-	// Honor the user's setting next. This is likely an install directory if it is not "./".
+	// Honor CRYPTOPP_DATA_DIR. This is likely an install directory if it is not "./".
 	name = AddSeparator(CRYPTOPP_DATA_DIR) + filename;
 	file.open(name.c_str());
 	if (file.is_open())
 		return name;
 #endif
-#ifndef CRYPTOPP_DISABLE_DATA_DIR_SEARCH
-	// Look in /usr/local/bin/share/. This is LSB and default install directory for users.
-	name = std::string("/usr/local/share/cryptopp/") + filename;
-	file.open(name.c_str());
-	if (file.is_open())
-		return name;
-#endif
-#ifndef CRYPTOPP_DISABLE_DATA_DIR_SEARCH
-	// Finally look in $ORIGIN/../share/. This is likely a Linux install directory for users.
-	name = std::string("../share/cryptopp/") + filename;
+
+#if CRYPTOPP_CXX11_DYNAMIC_INIT
+	static std::string path = AddSeparator(GetDataDir());
+	name = path + filename;
+	file.open(name.c_str());
+	if (file.is_open())
+		return name;
+#else
+	// Avoid static initialzation problems
+	name = AddSeparator(GetDataDir()) + filename;
 	file.open(name.c_str());
 	if (file.is_open())
 		return name;
 #endif
+
 	// This will cause the expected exception in the caller
 	return filename;
 }