1 files changed, 26 insertions, 17 deletions
diff --git a/src/test/util/random.cpp b/src/test/util/random.cpp
index 4c87ab8df8..32d785e45d 100644
--- a/src/test/util/random.cpp
+++ b/src/test/util/random.cpp
@@ -7,27 +7,36 @@
 #include <logging.h>
 #include <random.h>
 #include <uint256.h>
+#include <util/check.h>
 
 #include <cstdlib>
-#include <string>
+#include <iostream>
 
-FastRandomContext g_insecure_rand_ctx;
+extern void MakeRandDeterministicDANGEROUS(const uint256& seed) noexcept;
 
-/** Return the unsigned from the environment var if available, otherwise 0 */
-static uint256 GetUintFromEnv(const std::string& env_name)
+void SeedRandomStateForTest(SeedRand seedtype)
 {
-    const char* num = std::getenv(env_name.c_str());
-    if (!num) return {};
-    return uint256S(num);
-}
+    constexpr auto RANDOM_CTX_SEED{"RANDOM_CTX_SEED"};
 
-void Seed(FastRandomContext& ctx)
-{
-    // Should be enough to get the seed once for the process
-    static uint256 seed{};
-    static const std::string RANDOM_CTX_SEED{"RANDOM_CTX_SEED"};
-    if (seed.IsNull()) seed = GetUintFromEnv(RANDOM_CTX_SEED);
-    if (seed.IsNull()) seed = GetRandHash();
-    LogPrintf("%s: Setting random seed for current tests to %s=%s\n", __func__, RANDOM_CTX_SEED, seed.GetHex());
-    ctx = FastRandomContext(seed);
+    // Do this once, on the first call, regardless of seedtype, because once
+    // MakeRandDeterministicDANGEROUS is called, the output of GetRandHash is
+    // no longer truly random. It should be enough to get the seed once for the
+    // process.
+    static const uint256 ctx_seed = []() {
+        // If RANDOM_CTX_SEED is set, use that as seed.
+        if (const char* num{std::getenv(RANDOM_CTX_SEED)}) {
+            if (auto num_parsed{uint256::FromUserHex(num)}) {
+                return *num_parsed;
+            } else {
+                std::cerr << RANDOM_CTX_SEED << " must consist of up to " << uint256::size() * 2 << " hex digits (\"0x\" prefix allowed), it was set to: '" << num << "'.\n";
+                std::abort();
+            }
+        }
+        // Otherwise use a (truly) random value.
+        return GetRandHash();
+    }();
+
+    const uint256& seed{seedtype == SeedRand::FIXED_SEED ? ctx_seed : uint256::ZERO};
+    LogInfo("Setting random seed for current tests to %s=%s\n", RANDOM_CTX_SEED, seed.GetHex());
+    MakeRandDeterministicDANGEROUS(seed);
 }