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author | Pieter Wuille <pieter.wuille@gmail.com> | 2019-01-13 10:51:17 -0800 |
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committer | Pieter Wuille <pieter.wuille@gmail.com> | 2019-01-16 16:35:54 -0800 |
commit | 223de8d94d6522f795ec3c2e7db27469f24aa68c (patch) | |
tree | 60448895cf16e6ea5fef6dba41253bcc06208a9a /src/random.cpp | |
parent | f2e60ca98530e0a865ff6c6fd3c5633aec11a515 (diff) | |
download | bitcoin-223de8d94d6522f795ec3c2e7db27469f24aa68c.tar.xz |
Document RNG design in random.h
Diffstat (limited to 'src/random.cpp')
-rw-r--r-- | src/random.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/random.cpp b/src/random.cpp index 4cd6c9ddc1..3b7f7910b0 100644 --- a/src/random.cpp +++ b/src/random.cpp @@ -282,6 +282,14 @@ namespace { class RNGState { Mutex m_mutex; + /* The RNG state consists of 256 bits of entropy, taken from the output of + * one operation's SHA512 output, and fed as input to the next one. + * Carrying 256 bits of entropy should be sufficient to guarantee + * unpredictability as long as any entropy source was ever unpredictable + * to an attacker. To protect against situations where an attacker might + * observe the RNG's state, fresh entropy is always mixed when + * GetStrongRandBytes is called. + */ unsigned char m_state[32] GUARDED_BY(m_mutex) = {0}; uint64_t m_counter GUARDED_BY(m_mutex) = 0; bool m_strongly_seeded GUARDED_BY(m_mutex) = false; |