Merge #14955: Switch all RNG code to the built-in PRNG

223de8d94d Document RNG design in random.h (Pieter Wuille)
f2e60ca985 Use secure allocator for RNG state (Pieter Wuille)
cddb31bb0a Encapsulate RNGState better (Pieter Wuille)
152146e782 DRY: Implement GetRand using FastRandomContext::randrange (Pieter Wuille)
a1f252eda8 Sprinkle some sweet noexcepts over the RNG code (Pieter Wuille)
4ea8e50837 Remove hwrand_initialized. (Pieter Wuille)
9d7032e4f0 Switch all RNG code to the built-in PRNG. (Pieter Wuille)
16e40a8b56 Integrate util/system's CInit into RNGState (Pieter Wuille)
2ccc3d3aa3 Abstract out seeding/extracting entropy into RNGState::MixExtract (Pieter Wuille)
aae8b9bf0f Add thread safety annotations to RNG state (Pieter Wuille)
d3f54d1c82 Rename some hardware RNG related functions (Pieter Wuille)
05fde14e3a Automatically initialize RNG on first use. (Pieter Wuille)
2d1cc50939 Don't log RandAddSeedPerfmon details (Pieter Wuille)
6a57ca91da Use FRC::randbytes instead of reading >32 bytes from RNG (Pieter Wuille)

Pull request description:

  This does not remove OpenSSL, but makes our own PRNG the 'main' one; for GetStrongRandBytes, the OpenSSL RNG is still used (indirectly, by feeding its output into our PRNG state).

  It includes a few policy changes (regarding what entropy is seeded when).

  Before this PR:
  * GetRand*:
    * OpenSSL
  * GetStrongRand*:
    * CPU cycle counter
    * Perfmon data (on Windows, once 10 min)
    * /dev/urandom (or equivalent)
    * rdrand (if available)
  * From scheduler when idle:
    * CPU cycle counter before and after 1ms sleep
  * At startup:
    * CPU cycle counter before and after 1ms sleep

  After this PR:
  * GetRand*:
    * Stack pointer (which indirectly identifies thread and some call stack information)
    * rdrand (if available)
    * CPU cycle counter
  * GetStrongRand*:
    * Stack pointer (which indirectly identifies thread and some call stack information)
    * rdrand (if available)
    * CPU cycle counter
    * /dev/urandom (or equivalent)
    * OpenSSL
    * CPU cycle counter again
  * From scheduler when idle:
    * Stack pointer (which indirectly identifies thread and some call stack information)
    * rdrand (if available)
    * CPU cycle counter before and after 1ms sleep
    * Perfmon data (on Windows, once every 10 min)
  * At startup:
    * Stack pointer (which indirectly identifies thread and some call stack information)
    * rdrand (if available)
    * CPU cycle counter
    * /dev/urandom (or equivalent)
    * OpenSSL
    * CPU cycle counter again
    * Perfmon data (on Windows, once every 10 min)

  The interface of random.h is also simplified, and documentation is added.

  This implements most of #14623.

Tree-SHA512: 0120e19bd4ce80a509b5c180a4f29497d299ce8242e25755880851344b825bc2d64a222bc245e659562fb5463fb7c70fbfcf003616be4dc59d0ed6534f93dd20
This commit is contained in:
Wladimir J. van der Laan
2019-01-21 19:33:49 +01:00
8 changed files with 354 additions and 195 deletions

View File

@@ -73,9 +73,6 @@
#include <malloc.h>
#endif
#include <openssl/crypto.h>
#include <openssl/rand.h>
#include <openssl/conf.h>
#include <thread>
// Application startup time (used for uptime calculation)
@@ -86,54 +83,6 @@ const char * const BITCOIN_PID_FILENAME = "bitcoind.pid";
ArgsManager gArgs;
/** Init OpenSSL library multithreading support */
static std::unique_ptr<CCriticalSection[]> ppmutexOpenSSL;
void locking_callback(int mode, int i, const char* file, int line) NO_THREAD_SAFETY_ANALYSIS
{
if (mode & CRYPTO_LOCK) {
ENTER_CRITICAL_SECTION(ppmutexOpenSSL[i]);
} else {
LEAVE_CRITICAL_SECTION(ppmutexOpenSSL[i]);
}
}
// Singleton for wrapping OpenSSL setup/teardown.
class CInit
{
public:
CInit()
{
// Init OpenSSL library multithreading support
ppmutexOpenSSL.reset(new CCriticalSection[CRYPTO_num_locks()]);
CRYPTO_set_locking_callback(locking_callback);
// OpenSSL can optionally load a config file which lists optional loadable modules and engines.
// We don't use them so we don't require the config. However some of our libs may call functions
// which attempt to load the config file, possibly resulting in an exit() or crash if it is missing
// or corrupt. Explicitly tell OpenSSL not to try to load the file. The result for our libs will be
// that the config appears to have been loaded and there are no modules/engines available.
OPENSSL_no_config();
#ifdef WIN32
// Seed OpenSSL PRNG with current contents of the screen
RAND_screen();
#endif
// Seed OpenSSL PRNG with performance counter
RandAddSeed();
}
~CInit()
{
// Securely erase the memory used by the PRNG
RAND_cleanup();
// Shutdown OpenSSL library multithreading support
CRYPTO_set_locking_callback(nullptr);
// Clear the set of locks now to maintain symmetry with the constructor.
ppmutexOpenSSL.reset();
}
}
instance_of_cinit;
/** A map that contains all the currently held directory locks. After
* successful locking, these will be held here until the global destructor
* cleans them up and thus automatically unlocks them, or ReleaseDirectoryLocks