1 files changed, 283 insertions, 0 deletions
diff --git a/zerotierone/node/Utils.cpp b/zerotierone/node/Utils.cpp
new file mode 100644
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--- /dev/null
+++ b/zerotierone/node/Utils.cpp
@@ -0,0 +1,283 @@
+/*
+ * ZeroTier One - Network Virtualization Everywhere
+ * Copyright (C) 2011-2016  ZeroTier, Inc.  https://www.zerotier.com/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <time.h>
+#include <sys/stat.h>
+
+#include "Constants.hpp"
+
+#ifdef __UNIX_LIKE__
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+#include <dirent.h>
+#endif
+
+#ifdef __WINDOWS__
+#include <wincrypt.h>
+#endif
+
+#include "Utils.hpp"
+#include "Mutex.hpp"
+#include "Salsa20.hpp"
+
+namespace ZeroTier {
+
+const char Utils::HEXCHARS[16] = { '0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f' };
+
+static void _Utils_doBurn(char *ptr,unsigned int len)
+{
+	for(unsigned int i=0;i<len;++i)
+		ptr[i] = (char)0;
+}
+void (*volatile _Utils_doBurn_ptr)(char *,unsigned int) = _Utils_doBurn;
+void Utils::burn(void *ptr,unsigned int len)
+	throw()
+{
+	// Ridiculous hack: call _doBurn() via a volatile function pointer to
+	// hold down compiler optimizers and beat them mercilessly until they
+	// cry and mumble something about never eliding secure memory zeroing
+	// again.
+	(_Utils_doBurn_ptr)((char *)ptr,len);
+}
+
+std::string Utils::hex(const void *data,unsigned int len)
+{
+	std::string r;
+	r.reserve(len * 2);
+	for(unsigned int i=0;i<len;++i) {
+		r.push_back(HEXCHARS[(((const unsigned char *)data)[i] & 0xf0) >> 4]);
+		r.push_back(HEXCHARS[((const unsigned char *)data)[i] & 0x0f]);
+	}
+	return r;
+}
+
+std::string Utils::unhex(const char *hex,unsigned int maxlen)
+{
+	int n = 1;
+	unsigned char c,b = 0;
+	const char *eof = hex + maxlen;
+	std::string r;
+
+	if (!maxlen)
+		return r;
+
+	while ((c = (unsigned char)*(hex++))) {
+		if ((c >= 48)&&(c <= 57)) { // 0..9
+			if ((n ^= 1))
+				r.push_back((char)(b | (c - 48)));
+			else b = (c - 48) << 4;
+		} else if ((c >= 65)&&(c <= 70)) { // A..F
+			if ((n ^= 1))
+				r.push_back((char)(b | (c - (65 - 10))));
+			else b = (c - (65 - 10)) << 4;
+		} else if ((c >= 97)&&(c <= 102)) { // a..f
+			if ((n ^= 1))
+				r.push_back((char)(b | (c - (97 - 10))));
+			else b = (c - (97 - 10)) << 4;
+		}
+		if (hex == eof)
+			break;
+	}
+
+	return r;
+}
+
+unsigned int Utils::unhex(const char *hex,unsigned int maxlen,void *buf,unsigned int len)
+{
+	int n = 1;
+	unsigned char c,b = 0;
+	unsigned int l = 0;
+	const char *eof = hex + maxlen;
+
+	if (!maxlen)
+		return 0;
+
+	while ((c = (unsigned char)*(hex++))) {
+		if ((c >= 48)&&(c <= 57)) { // 0..9
+			if ((n ^= 1)) {
+				if (l >= len) break;
+				((unsigned char *)buf)[l++] = (b | (c - 48));
+			} else b = (c - 48) << 4;
+		} else if ((c >= 65)&&(c <= 70)) { // A..F
+			if ((n ^= 1)) {
+				if (l >= len) break;
+				((unsigned char *)buf)[l++] = (b | (c - (65 - 10)));
+			} else b = (c - (65 - 10)) << 4;
+		} else if ((c >= 97)&&(c <= 102)) { // a..f
+			if ((n ^= 1)) {
+				if (l >= len) break;
+				((unsigned char *)buf)[l++] = (b | (c - (97 - 10)));
+			} else b = (c - (97 - 10)) << 4;
+		}
+		if (hex == eof)
+			break;
+	}
+
+	return l;
+}
+
+void Utils::getSecureRandom(void *buf,unsigned int bytes)
+{
+	static Mutex globalLock;
+	static Salsa20 s20;
+	static bool s20Initialized = false;
+
+	Mutex::Lock _l(globalLock);
+
+	/* Just for posterity we Salsa20 encrypt the result of whatever system
+	 * CSPRNG we use. There have been several bugs at the OS or OS distribution
+	 * level in the past that resulted in systematically weak or predictable
+	 * keys due to random seeding problems. This mitigates that by grabbing
+	 * a bit of extra entropy and further randomizing the result, and comes
+	 * at almost no cost and with no real downside if the random source is
+	 * good. */
+	if (!s20Initialized) {
+		s20Initialized = true;
+		uint64_t s20Key[4];
+		s20Key[0] = (uint64_t)time(0); // system clock
+		s20Key[1] = (uint64_t)buf; // address of buf
+		s20Key[2] = (uint64_t)s20Key; // address of s20Key[]
+		s20Key[3] = (uint64_t)&s20; // address of s20
+		s20.init(s20Key,256,s20Key);
+	}
+
+#ifdef __WINDOWS__
+
+	static HCRYPTPROV cryptProvider = NULL;
+
+	if (cryptProvider == NULL) {
+		if (!CryptAcquireContextA(&cryptProvider,NULL,NULL,PROV_RSA_FULL,CRYPT_VERIFYCONTEXT|CRYPT_SILENT)) {
+			fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() unable to obtain WinCrypt context!\r\n");
+			exit(1);
+			return;
+		}
+	}
+	if (!CryptGenRandom(cryptProvider,(DWORD)bytes,(BYTE *)buf)) {
+		fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() CryptGenRandom failed!\r\n");
+		exit(1);
+	}
+
+#else // not __WINDOWS__
+
+	static char randomBuf[131072];
+	static unsigned int randomPtr = sizeof(randomBuf);
+	static int devURandomFd = -1;
+
+	if (devURandomFd <= 0) {
+		devURandomFd = ::open("/dev/urandom",O_RDONLY);
+		if (devURandomFd <= 0) {
+			fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() unable to open /dev/urandom\n");
+			exit(1);
+			return;
+		}
+	}
+
+	for(unsigned int i=0;i<bytes;++i) {
+		if (randomPtr >= sizeof(randomBuf)) {
+			for(;;) {
+				if ((int)::read(devURandomFd,randomBuf,sizeof(randomBuf)) != (int)sizeof(randomBuf)) {
+					::close(devURandomFd);
+					devURandomFd = ::open("/dev/urandom",O_RDONLY);
+					if (devURandomFd <= 0) {
+						fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() unable to open /dev/urandom\n");
+						exit(1);
+						return;
+					}
+				} else break;
+			}
+			randomPtr = 0;
+		}
+		((char *)buf)[i] = randomBuf[randomPtr++];
+	}
+
+#endif // __WINDOWS__ or not
+
+	s20.encrypt12(buf,buf,bytes);
+}
+
+std::vector<std::string> Utils::split(const char *s,const char *const sep,const char *esc,const char *quot)
+{
+	std::vector<std::string> fields;
+	std::string buf;
+
+	if (!esc)
+		esc = "";
+	if (!quot)
+		quot = "";
+
+	bool escapeState = false;
+	char quoteState = 0;
+	while (*s) {
+		if (escapeState) {
+			escapeState = false;
+			buf.push_back(*s);
+		} else if (quoteState) {
+			if (*s == quoteState) {
+				quoteState = 0;
+				fields.push_back(buf);
+				buf.clear();
+			} else buf.push_back(*s);
+		} else {
+			const char *quotTmp;
+			if (strchr(esc,*s))
+				escapeState = true;
+			else if ((buf.size() <= 0)&&((quotTmp = strchr(quot,*s))))
+				quoteState = *quotTmp;
+			else if (strchr(sep,*s)) {
+				if (buf.size() > 0) {
+					fields.push_back(buf);
+					buf.clear();
+				} // else skip runs of seperators
+			} else buf.push_back(*s);
+		}
+		++s;
+	}
+
+	if (buf.size())
+		fields.push_back(buf);
+
+	return fields;
+}
+
+unsigned int Utils::snprintf(char *buf,unsigned int len,const char *fmt,...)
+	throw(std::length_error)
+{
+	va_list ap;
+
+	va_start(ap,fmt);
+	int n = (int)vsnprintf(buf,len,fmt,ap);
+	va_end(ap);
+
+	if ((n >= (int)len)||(n < 0)) {
+		if (len)
+			buf[len - 1] = (char)0;
+		throw std::length_error("buf[] overflow in Utils::snprintf");
+	}
+
+	return (unsigned int)n;
+}
+
+} // namespace ZeroTier