kernel: Remove key module from kernel library

The key module's functionality is not used by the kernel library, but
currently kernel users are still required to initialize the key module's
`secp256k1_context_sign` global as part of the `kernel::Context` through
`ECC_Start`.

Author: TheCharlatan

src/Makefile.am

@@ -945,7 +945,6 @@ libbitcoinkernel_la_SOURCES = \
   kernel/disconnected_transactions.cpp \
   kernel/mempool_persist.cpp \
   kernel/mempool_removal_reason.cpp \
-  key.cpp \
   logging.cpp \
   node/blockstorage.cpp \
   node/chainstate.cpp \

src/bitcoin-chainstate.cpp

@@ -26,6 +26,7 @@
 #include <script/sigcache.h>
 #include <util/chaintype.h>
 #include <util/fs.h>
+#include <util/signalinterrupt.h>
 #include <util/task_runner.h>
 #include <validation.h>
 #include <validationinterface.h>

src/bitcoind.cpp

@@ -14,11 +14,13 @@
 #include <init.h>
 #include <interfaces/chain.h>
 #include <interfaces/init.h>
+#include <kernel/context.h>
 #include <node/context.h>
 #include <node/interface_ui.h>
 #include <noui.h>
 #include <util/check.h>
 #include <util/exception.h>
+#include <util/signalinterrupt.h>
 #include <util/strencodings.h>
 #include <util/syserror.h>
 #include <util/threadnames.h>
@@ -180,6 +182,7 @@ static bool AppInit(NodeContext& node)
         }
 
         node.kernel = std::make_unique<kernel::Context>();
+        node.ecc_context = std::make_unique<ECC_Context>();
         if (!AppInitSanityChecks(*node.kernel))
         {
             // InitError will have been called with detailed error, which ends up on console

src/init.cpp

@@ -32,6 +32,8 @@
 #include <interfaces/chain.h>
 #include <interfaces/init.h>
 #include <interfaces/node.h>
+#include <kernel/context.h>
+#include <key.h>
 #include <logging.h>
 #include <mapport.h>
 #include <net.h>
@@ -75,6 +77,7 @@
 #include <util/fs_helpers.h>
 #include <util/moneystr.h>
 #include <util/result.h>
+#include <util/signalinterrupt.h>
 #include <util/strencodings.h>
 #include <util/string.h>
 #include <util/syserror.h>
@@ -371,6 +374,7 @@ void Shutdown(NodeContext& node)
     node.chainman.reset();
     node.validation_signals.reset();
     node.scheduler.reset();
+    node.ecc_context.reset();
     node.kernel.reset();
 
     RemovePidFile(*node.args);
@@ -1084,6 +1088,10 @@ bool AppInitSanityChecks(const kernel::Context& kernel)
         return InitError(strprintf(_("Initialization sanity check failed. %s is shutting down."), PACKAGE_NAME));
     }
 
+    if (!ECC_InitSanityCheck()) {
+        return InitError(strprintf(_("Elliptic curve cryptography sanity check failure. %s is shutting down."), PACKAGE_NAME));
+    }
+
     // Probe the data directory lock to give an early error message, if possible
     // We cannot hold the data directory lock here, as the forking for daemon() hasn't yet happened,
     // and a fork will cause weird behavior to it.

src/kernel/checks.cpp

@@ -4,8 +4,8 @@
 
 #include <kernel/checks.h>
 
-#include <key.h>
 #include <random.h>
+#include <util/result.h>
 #include <util/translation.h>
 
 #include <memory>
@@ -14,10 +14,6 @@ namespace kernel {
 
 util::Result<void> SanityChecks(const Context&)
 {
-    if (!ECC_InitSanityCheck()) {
-        return util::Error{Untranslated("Elliptic curve cryptography sanity check failure. Aborting.")};
-    }
-
     if (!Random_SanityCheck()) {
         return util::Error{Untranslated("OS cryptographic RNG sanity check failure. Aborting.")};
     }

src/kernel/context.cpp

@@ -5,9 +5,7 @@
 #include <kernel/context.h>
 
 #include <crypto/sha256.h>
-#include <key.h>
 #include <logging.h>
-#include <pubkey.h>
 #include <random.h>
 
 #include <string>
@@ -19,12 +17,7 @@ Context::Context()
     std::string sha256_algo = SHA256AutoDetect();
     LogPrintf("Using the '%s' SHA256 implementation\n", sha256_algo);
     RandomInit();
-    ECC_Start();
 }
 
-Context::~Context()
-{
-    ECC_Stop();
-}
 
 } // namespace kernel

src/kernel/context.h

@@ -5,10 +5,6 @@
 #ifndef BITCOIN_KERNEL_CONTEXT_H
 #define BITCOIN_KERNEL_CONTEXT_H
 
-#include <util/signalinterrupt.h>
-
-#include <memory>
-
 namespace kernel {
 //! Context struct holding the kernel library's logically global state, and
 //! passed to external libbitcoin_kernel functions which need access to this
@@ -19,7 +15,6 @@ namespace kernel {
 //! should be stored to std::unique_ptr members pointing to opaque types.
 struct Context {
     Context();
-    ~Context();
 };
 } // namespace kernel
 

src/node/context.cpp

@@ -8,6 +8,7 @@
 #include <banman.h>
 #include <interfaces/chain.h>
 #include <kernel/context.h>
+#include <key.h>
 #include <net.h>
 #include <net_processing.h>
 #include <netgroup.h>
@@ -16,6 +17,7 @@
 #include <scheduler.h>
 #include <txmempool.h>
 #include <validation.h>
+#include <validationinterface.h>
 
 namespace node {
 NodeContext::NodeContext() = default;

src/node/context.h

@@ -5,10 +5,7 @@
 #ifndef BITCOIN_NODE_CONTEXT_H
 #define BITCOIN_NODE_CONTEXT_H
 
-#include <kernel/context.h>
-
 #include <atomic>
-#include <cassert>
 #include <cstdlib>
 #include <functional>
 #include <memory>
@@ -24,6 +21,7 @@ class ValidationSignals;
 class CScheduler;
 class CTxMemPool;
 class ChainstateManager;
+class ECC_Context;
 class NetGroupManager;
 class PeerManager;
 namespace interfaces {
@@ -32,6 +30,12 @@ class ChainClient;
 class Init;
 class WalletLoader;
 } // namespace interfaces
+namespace kernel {
+struct Context;
+}
+namespace util {
+class SignalInterrupt;
+}
 
 namespace node {
 class KernelNotifications;
@@ -49,6 +53,7 @@ class KernelNotifications;
 struct NodeContext {
     //! libbitcoin_kernel context
     std::unique_ptr<kernel::Context> kernel;
+    std::unique_ptr<ECC_Context> ecc_context;
     //! Init interface for initializing current process and connecting to other processes.
     interfaces::Init* init{nullptr};
     //! Interrupt object used to track whether node shutdown was requested.

src/node/interfaces.cpp

@@ -17,6 +17,7 @@
 #include <interfaces/node.h>
 #include <interfaces/wallet.h>
 #include <kernel/chain.h>
+#include <kernel/context.h>
 #include <kernel/mempool_entry.h>
 #include <logging.h>
 #include <mapport.h>
@@ -99,6 +100,7 @@ class NodeImpl : public Node
         if (!AppInitParameterInteraction(args())) return false;
 
         m_context->kernel = std::make_unique<kernel::Context>();
+        m_context->ecc_context = std::make_unique<ECC_Context>();
         if (!AppInitSanityChecks(*m_context->kernel)) return false;
 
         if (!AppInitLockDataDirectory()) return false;