From 65f16dbcefa26eeaf04a1df4b0d83a01d5e4701e Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter.wuille@gmail.com>
Date: Tue, 5 Nov 2019 10:54:20 -0800
Subject: [PATCH] Report amount of data gathered from environment

Cherry-picked from: d1c02775aa74a0610809ac54bb241ddad61d2d8c
---
 src/crypto/sha512.h | 1 +
 src/random.cpp      | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/src/crypto/sha512.h b/src/crypto/sha512.h
index 01fd896aabc..ccb7b7af2c8 100644
--- a/src/crypto/sha512.h
+++ b/src/crypto/sha512.h
@@ -24,6 +24,7 @@ class CSHA512
     CSHA512& Write(const unsigned char* data, size_t len);
     void Finalize(unsigned char hash[OUTPUT_SIZE]);
     CSHA512& Reset();
+    uint64_t Size() const { return bytes; }
 };
 
 void detect_sha512_hardware(void);
diff --git a/src/random.cpp b/src/random.cpp
index 80ec2a151fc..1e00b6503ff 100644
--- a/src/random.cpp
+++ b/src/random.cpp
@@ -444,7 +444,9 @@ static void SeedPeriodic(CSHA512& hasher, RNGState& rng)
     SeedTimestamp(hasher);
 
     // Dynamic environment data (performance monitoring, ...)
+    auto old_size = hasher.Size();
     RandAddDynamicEnv(hasher);
+    LogPrintf("Feeding %i bytes of dynamic environment data into RNG\n", hasher.Size() - old_size);
 
     // Strengthen for 10 ms
     SeedStrengthen(hasher, rng, 10000);
@@ -460,10 +462,12 @@ static void SeedStartup(CSHA512& hasher, RNGState& rng) noexcept
     SeedSlow(hasher);
 
     // Dynamic environment data (performance monitoring, ...)
+    auto old_size = hasher.Size();
     RandAddDynamicEnv(hasher);
 
     // Static environment data
     RandAddStaticEnv(hasher);
+    LogPrintf("Feeding %i bytes of environment data into RNG\n", hasher.Size() - old_size);
 
     // Strengthen for 100 ms
     SeedStrengthen(hasher, rng, 100000);