From 4f1c37980e13167f01cd6fdc07b201bf4dabbf52 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Mon, 4 Jan 2016 07:30:53 -0700
Subject: [PATCH] Load proving/verifying keys at startup from the public alpha
 parameters file.

---
 src/init.cpp              | 43 +++++++++++++++++++++++++++++++++
 src/init.h                |  3 +++
 src/test/test_bitcoin.cpp |  1 +
 src/util.cpp              | 51 +++++++++++++++++++++++++++++++++++++++
 src/util.h                |  2 ++
 5 files changed, 100 insertions(+)

diff --git a/src/init.cpp b/src/init.cpp
index a04e4e0a..ff47a843 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -49,6 +49,8 @@
 
 using namespace std;
 
+libzerocash::ZerocashParams *pzerocashParams = NULL;
+
 #ifdef ENABLE_WALLET
 CWallet* pwalletMain = NULL;
 #endif
@@ -591,6 +593,44 @@ bool InitSanityCheck(void)
     return true;
 }
 
+
+static void ZC_LoadParams()
+{
+    struct timeval tv_start, tv_end;
+    float elapsed;
+
+    boost::filesystem::path pk_path = ZC_GetParamsDir() / "zc-testnet-public-alpha-proving.key";
+    boost::filesystem::path vk_path = ZC_GetParamsDir() / "zc-testnet-public-alpha-verification.key";
+
+    LogPrintf("Loading proving key from %s\n", pk_path.string().c_str());
+    gettimeofday(&tv_start, 0);
+    libzerocash::ZerocashParams::zerocash_pp::init_public_params();
+    auto pk_loaded = libzerocash::ZerocashParams::LoadProvingKeyFromFile(
+        pk_path.string(),
+        INCREMENTAL_MERKLE_TREE_DEPTH
+    );
+    gettimeofday(&tv_end, 0);
+    elapsed = float(tv_end.tv_sec-tv_start.tv_sec) + (tv_end.tv_usec-tv_start.tv_usec)/float(1000000);
+    LogPrintf("Loaded proving key in %fs seconds.\n", elapsed);
+
+
+    LogPrintf("Loading verification key from %s\n", vk_path.string().c_str());
+    gettimeofday(&tv_start, 0);
+    auto vk_loaded = libzerocash::ZerocashParams::LoadVerificationKeyFromFile(
+        vk_path.string(),
+        INCREMENTAL_MERKLE_TREE_DEPTH
+    );
+    gettimeofday(&tv_end, 0);
+    elapsed = float(tv_end.tv_sec-tv_start.tv_sec) + (tv_end.tv_usec-tv_start.tv_usec)/float(1000000);
+    LogPrintf("Loaded verification key in %fs seconds.\n", elapsed);
+
+    pzerocashParams = new libzerocash::ZerocashParams(
+        INCREMENTAL_MERKLE_TREE_DEPTH,
+        &pk_loaded,
+        &vk_loaded
+    );
+}
+
 /** Initialize bitcoin.
  *  @pre Parameters should be parsed and config file should be read.
  */
@@ -1223,6 +1263,9 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         mempool.ReadFeeEstimates(est_filein);
     fFeeEstimatesInitialized = true;
 
+    // ********************************************************* Step 7i: Load zcash params
+    ZC_LoadParams();
+
     // ********************************************************* Step 8: load wallet
 #ifdef ENABLE_WALLET
     if (fDisableWallet) {
diff --git a/src/init.h b/src/init.h
index dcb2b293..0dd6da7e 100644
--- a/src/init.h
+++ b/src/init.h
@@ -8,6 +8,8 @@
 
 #include <string>
 
+#include "libzerocash/ZerocashParams.h"
+
 class CScheduler;
 class CWallet;
 
@@ -17,6 +19,7 @@ class thread_group;
 } // namespace boost
 
 extern CWallet* pwalletMain;
+extern libzerocash::ZerocashParams* pzerocashParams;
 
 void StartShutdown();
 bool ShutdownRequested();
diff --git a/src/test/test_bitcoin.cpp b/src/test/test_bitcoin.cpp
index c727303e..fa322dcd 100644
--- a/src/test/test_bitcoin.cpp
+++ b/src/test/test_bitcoin.cpp
@@ -23,6 +23,7 @@
 
 CClientUIInterface uiInterface; // Declared but not defined in ui_interface.h
 CWallet* pwalletMain;
+libzerocash::ZerocashParams *pzerocashParams;
 
 extern bool fPrintToConsole;
 extern void noui_connect();
diff --git a/src/util.cpp b/src/util.cpp
index 4fc2d339..b4d3fa6b 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -430,8 +430,59 @@ boost::filesystem::path GetDefaultDataDir()
 
 static boost::filesystem::path pathCached;
 static boost::filesystem::path pathCachedNetSpecific;
+static boost::filesystem::path zc_paramsPathCached;
 static CCriticalSection csPathCached;
 
+static boost::filesystem::path ZC_GetBaseParamsDir()
+{
+    // Copied from GetDefaultDataDir and adapter for zcash params.
+
+    namespace fs = boost::filesystem;
+    // Windows < Vista: C:\Documents and Settings\Username\Application Data\ZcashParams
+    // Windows >= Vista: C:\Users\Username\AppData\Roaming\ZcashParams
+    // Mac: ~/Library/Application Support/ZcashParams
+    // Unix: ~/.zcash-params
+#ifdef WIN32
+    // Windows
+    return GetSpecialFolderPath(CSIDL_APPDATA) / "ZcashParams";
+#else
+    fs::path pathRet;
+    char* pszHome = getenv("HOME");
+    if (pszHome == NULL || strlen(pszHome) == 0)
+        pathRet = fs::path("/");
+    else
+        pathRet = fs::path(pszHome);
+#ifdef MAC_OSX
+    // Mac
+    pathRet /= "Library/Application Support";
+    TryCreateDirectory(pathRet);
+    return pathRet / "ZcashParams";
+#else
+    // Unix
+    return pathRet / ".zcash-params";
+#endif
+#endif
+}
+
+const boost::filesystem::path &ZC_GetParamsDir()
+{
+    namespace fs = boost::filesystem;
+
+    LOCK(csPathCached); // Reuse the same lock as upstream.
+
+    fs::path &path = zc_paramsPathCached;
+
+    // This can be called during exceptions by LogPrintf(), so we cache the
+    // value so we don't have to do memory allocations after that.
+    if (!path.empty())
+        return path;
+
+    path = ZC_GetBaseParamsDir();
+    path /= BaseParams().DataDir();
+
+    return path;
+}
+
 const boost::filesystem::path &GetDataDir(bool fNetSpecific)
 {
     namespace fs = boost::filesystem;
diff --git a/src/util.h b/src/util.h
index 4cc0faf4..336e2b1b 100644
--- a/src/util.h
+++ b/src/util.h
@@ -104,6 +104,8 @@ static inline bool error(const char* format)
     return false;
 }
 
+const boost::filesystem::path &ZC_GetParamsDir();
+
 void PrintExceptionContinue(const std::exception *pex, const char* pszThread);
 void ParseParameters(int argc, const char*const argv[]);
 void FileCommit(FILE *fileout);