68e021e3a3
fbf327b Minimal code changes to allow msvc compilation. (Aaron Clauson)
Pull request description:
These changes are required to allow the Bitcoin source to build with Microsoft's C++ compiler (#11562 is also required).
I looked around for a better place for the typedef of ssize_t which is in random.h. The best candidate looks like src/compat.h but I figured including that header in random.h is a bigger change than the typedef. Note that the same typedef is in at least two other places including the OpenSSL and Berkeley DB headers so some of the Bitcoin code already picks it up.
Tree-SHA512: aa6cc6283015e08ab074641f9abdc116c4dc58574dc90f75e7a5af4cc82946d3052370e5cbe855fb6180c00f8dc66997d3724ff0412e4b7417e51b6602154825
147 lines
3.7 KiB
C++
147 lines
3.7 KiB
C++
// Copyright (c) 2009-2010 Satoshi Nakamoto
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// Copyright (c) 2009-2016 The Bitcoin Core developers
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// Distributed under the MIT software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#ifndef BITCOIN_RANDOM_H
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#define BITCOIN_RANDOM_H
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#include <crypto/chacha20.h>
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#include <crypto/common.h>
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#include <uint256.h>
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#include <stdint.h>
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/* Seed OpenSSL PRNG with additional entropy data */
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void RandAddSeed();
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/**
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* Functions to gather random data via the OpenSSL PRNG
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*/
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void GetRandBytes(unsigned char* buf, int num);
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uint64_t GetRand(uint64_t nMax);
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int GetRandInt(int nMax);
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uint256 GetRandHash();
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/**
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* Add a little bit of randomness to the output of GetStrongRangBytes.
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* This sleeps for a millisecond, so should only be called when there is
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* no other work to be done.
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*/
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void RandAddSeedSleep();
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/**
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* Function to gather random data from multiple sources, failing whenever any
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* of those source fail to provide a result.
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*/
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void GetStrongRandBytes(unsigned char* buf, int num);
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/**
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* Fast randomness source. This is seeded once with secure random data, but
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* is completely deterministic and insecure after that.
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* This class is not thread-safe.
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*/
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class FastRandomContext {
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private:
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bool requires_seed;
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ChaCha20 rng;
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unsigned char bytebuf[64];
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int bytebuf_size;
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uint64_t bitbuf;
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int bitbuf_size;
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void RandomSeed();
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void FillByteBuffer()
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{
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if (requires_seed) {
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RandomSeed();
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}
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rng.Output(bytebuf, sizeof(bytebuf));
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bytebuf_size = sizeof(bytebuf);
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}
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void FillBitBuffer()
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{
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bitbuf = rand64();
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bitbuf_size = 64;
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}
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public:
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explicit FastRandomContext(bool fDeterministic = false);
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/** Initialize with explicit seed (only for testing) */
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explicit FastRandomContext(const uint256& seed);
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/** Generate a random 64-bit integer. */
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uint64_t rand64()
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{
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if (bytebuf_size < 8) FillByteBuffer();
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uint64_t ret = ReadLE64(bytebuf + 64 - bytebuf_size);
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bytebuf_size -= 8;
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return ret;
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}
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/** Generate a random (bits)-bit integer. */
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uint64_t randbits(int bits) {
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if (bits == 0) {
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return 0;
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} else if (bits > 32) {
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return rand64() >> (64 - bits);
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} else {
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if (bitbuf_size < bits) FillBitBuffer();
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uint64_t ret = bitbuf & (~(uint64_t)0 >> (64 - bits));
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bitbuf >>= bits;
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bitbuf_size -= bits;
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return ret;
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}
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}
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/** Generate a random integer in the range [0..range). */
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uint64_t randrange(uint64_t range)
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{
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--range;
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int bits = CountBits(range);
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while (true) {
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uint64_t ret = randbits(bits);
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if (ret <= range) return ret;
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}
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}
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/** Generate random bytes. */
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std::vector<unsigned char> randbytes(size_t len);
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/** Generate a random 32-bit integer. */
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uint32_t rand32() { return randbits(32); }
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/** generate a random uint256. */
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uint256 rand256();
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/** Generate a random boolean. */
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bool randbool() { return randbits(1); }
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};
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/* Number of random bytes returned by GetOSRand.
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* When changing this constant make sure to change all call sites, and make
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* sure that the underlying OS APIs for all platforms support the number.
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* (many cap out at 256 bytes).
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*/
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static const int NUM_OS_RANDOM_BYTES = 32;
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/** Get 32 bytes of system entropy. Do not use this in application code: use
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* GetStrongRandBytes instead.
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*/
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void GetOSRand(unsigned char *ent32);
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/** Check that OS randomness is available and returning the requested number
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* of bytes.
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*/
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bool Random_SanityCheck();
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/** Initialize the RNG. */
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void RandomInit();
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#endif // BITCOIN_RANDOM_H
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