ZeroTierOne/node/Utils.cpp

283 lines
6.9 KiB
C++

/*
* ZeroTier One - Network Virtualization Everywhere
* Copyright (C) 2011-2015 ZeroTier, Inc.
*
* 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/>.
*
* --
*
* ZeroTier may be used and distributed under the terms of the GPLv3, which
* are available at: http://www.gnu.org/licenses/gpl-3.0.html
*
* If you would like to embed ZeroTier into a commercial application or
* redistribute it in a modified binary form, please contact ZeroTier Networks
* LLC. Start here: http://www.zerotier.com/
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.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)
{
#ifdef __WINDOWS__
static HCRYPTPROV cryptProvider = NULL;
static Mutex globalLock;
static Salsa20 s20;
Mutex::Lock _l(globalLock);
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;
}
char s20key[32];
if (!CryptGenRandom(cryptProvider,(DWORD)sizeof(s20key),(BYTE *)s20key)) {
fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() CryptGenRandom failed!\r\n");
exit(1);
}
s20.init(s20key,256,s20key,8);
}
if (!CryptGenRandom(cryptProvider,(DWORD)bytes,(BYTE *)buf)) {
fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() CryptGenRandom failed!\r\n");
exit(1);
}
s20.encrypt(buf,buf,bytes);
#else // not __WINDOWS__
#ifdef __UNIX_LIKE__
static char randomBuf[65536];
static unsigned int randomPtr = sizeof(randomBuf);
static int devURandomFd = -1;
static Mutex globalLock;
Mutex::Lock _l(globalLock);
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)) {
if ((int)::read(devURandomFd,randomBuf,sizeof(randomBuf)) != (int)sizeof(randomBuf)) {
fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() unable to read from /dev/urandom\n");
exit(1);
return;
}
randomPtr = 0;
}
((char *)buf)[i] = randomBuf[randomPtr++];
}
#else // not __UNIX_LIKE__
#error No getSecureRandom() implementation available.
#endif // __UNIX_LIKE__
#endif // __WINDOWS__
}
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