Revert "SERVER-43641 upgrade random.h"

This reverts commit 96da177c6ae7b7ed0f29983ad033d8a59524b0b2.

1 files changed, 9 insertions, 3 deletions

diff --git a/src/mongo/db/time_proof_service.cpp b/src/mongo/db/time_proof_service.cpp
index da65e441712..7e29f0b2254 100644
--- a/src/mongo/db/time_proof_service.cpp
+++ b/src/mongo/db/time_proof_service.cpp
@@ -45,9 +45,15 @@ namespace mongo {
 const uint64_t kRangeMask = 0x0000'0000'0000'FFFF;
 
 TimeProofService::Key TimeProofService::generateRandomKey() {
-    std::array<std::uint8_t, SHA1Block::kHashLength> keyBuffer;
-    SecureRandom().fill(keyBuffer.data(), keyBuffer.size());
-    return fassert(40384, SHA1Block::fromBuffer(keyBuffer.data(), keyBuffer.size()));
+    // SecureRandom only produces 64-bit numbers, so 3 is the minimum for 20 random bytes.
+    const size_t kRandomNumbers = 3;
+    std::array<std::int64_t, kRandomNumbers> keyBuffer;
+    std::unique_ptr<SecureRandom> rng(SecureRandom::create());
+    std::generate(keyBuffer.begin(), keyBuffer.end(), [&] { return rng->nextInt64(); });
+
+    return fassert(40384,
+                   SHA1Block::fromBuffer(reinterpret_cast<std::uint8_t*>(keyBuffer.data()),
+                                         SHA1Block::kHashLength));
 }
 
 TimeProofService::TimeProof TimeProofService::getProof(LogicalTime time, const Key& key) {