mirror of
https://github.com/zerotier/ZeroTierOne.git
synced 2024-12-19 13:07:55 +00:00
256 lines
6.7 KiB
C++
256 lines
6.7 KiB
C++
/*
|
|
* 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' };
|
|
|
|
// Crazy hack to force memory to be securely zeroed in spite of the best efforts of optimizing compilers.
|
|
static void _Utils_doBurn(volatile uint8_t *ptr,unsigned int len)
|
|
{
|
|
volatile uint8_t *const end = ptr + len;
|
|
while (ptr != end) *(ptr++) = (uint8_t)0;
|
|
}
|
|
static void (*volatile _Utils_doBurn_ptr)(volatile uint8_t *,unsigned int) = _Utils_doBurn;
|
|
void Utils::burn(void *ptr,unsigned int len) { (_Utils_doBurn_ptr)((volatile uint8_t *)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;
|
|
static uint8_t randomBuf[65536];
|
|
static unsigned int randomPtr = sizeof(randomBuf);
|
|
|
|
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;
|
|
|
|
for(unsigned int i=0;i<bytes;++i) {
|
|
if (randomPtr >= sizeof(randomBuf)) {
|
|
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);
|
|
}
|
|
}
|
|
if (!CryptGenRandom(cryptProvider,(DWORD)sizeof(randomBuf),(BYTE *)randomBuf)) {
|
|
fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() CryptGenRandom failed!\r\n");
|
|
exit(1);
|
|
}
|
|
randomPtr = 0;
|
|
s20.crypt12(randomBuf,randomBuf,sizeof(randomBuf));
|
|
}
|
|
((uint8_t *)buf)[i] = randomBuf[randomPtr++];
|
|
}
|
|
|
|
#else // not __WINDOWS__
|
|
|
|
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;
|
|
s20.crypt12(randomBuf,randomBuf,sizeof(randomBuf));
|
|
}
|
|
((uint8_t *)buf)[i] = randomBuf[randomPtr++];
|
|
}
|
|
|
|
#endif // __WINDOWS__ or not
|
|
}
|
|
|
|
bool Utils::scopy(char *dest,unsigned int len,const char *src)
|
|
{
|
|
if (!len)
|
|
return false; // sanity check
|
|
if (!src) {
|
|
*dest = (char)0;
|
|
return true;
|
|
}
|
|
char *end = dest + len;
|
|
while ((*dest++ = *src++)) {
|
|
if (dest == end) {
|
|
*(--dest) = (char)0;
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
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
|