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Diffstat (limited to '')
-rw-r--r-- | security/sandbox/chromium/base/rand_util.h | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/rand_util.h b/security/sandbox/chromium/base/rand_util.h new file mode 100644 index 0000000000..45e4283223 --- /dev/null +++ b/security/sandbox/chromium/base/rand_util.h @@ -0,0 +1,78 @@ +// Copyright (c) 2012 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef BASE_RAND_UTIL_H_ +#define BASE_RAND_UTIL_H_ + +#include <stddef.h> +#include <stdint.h> + +#include <algorithm> +#include <string> + +#include "base/base_export.h" +#include "build/build_config.h" + +namespace base { + +// Returns a random number in range [0, UINT64_MAX]. Thread-safe. +BASE_EXPORT uint64_t RandUint64(); + +// Returns a random number between min and max (inclusive). Thread-safe. +BASE_EXPORT int RandInt(int min, int max); + +// Returns a random number in range [0, range). Thread-safe. +BASE_EXPORT uint64_t RandGenerator(uint64_t range); + +// Returns a random double in range [0, 1). Thread-safe. +BASE_EXPORT double RandDouble(); + +// Given input |bits|, convert with maximum precision to a double in +// the range [0, 1). Thread-safe. +BASE_EXPORT double BitsToOpenEndedUnitInterval(uint64_t bits); + +// Fills |output_length| bytes of |output| with random data. Thread-safe. +// +// Although implementations are required to use a cryptographically secure +// random number source, code outside of base/ that relies on this should use +// crypto::RandBytes instead to ensure the requirement is easily discoverable. +BASE_EXPORT void RandBytes(void* output, size_t output_length); + +// Fills a string of length |length| with random data and returns it. +// |length| should be nonzero. Thread-safe. +// +// Note that this is a variation of |RandBytes| with a different return type. +// The returned string is likely not ASCII/UTF-8. Use with care. +// +// Although implementations are required to use a cryptographically secure +// random number source, code outside of base/ that relies on this should use +// crypto::RandBytes instead to ensure the requirement is easily discoverable. +BASE_EXPORT std::string RandBytesAsString(size_t length); + +// An STL UniformRandomBitGenerator backed by RandUint64. +// TODO(tzik): Consider replacing this with a faster implementation. +class RandomBitGenerator { + public: + using result_type = uint64_t; + static constexpr result_type min() { return 0; } + static constexpr result_type max() { return UINT64_MAX; } + result_type operator()() const { return RandUint64(); } + + RandomBitGenerator() = default; + ~RandomBitGenerator() = default; +}; + +// Shuffles [first, last) randomly. Thread-safe. +template <typename Itr> +void RandomShuffle(Itr first, Itr last) { + std::shuffle(first, last, RandomBitGenerator()); +} + +#if defined(OS_POSIX) +BASE_EXPORT int GetUrandomFD(); +#endif + +} // namespace base + +#endif // BASE_RAND_UTIL_H_ |