Avoid downloading large sprout param files

src/init.cpp

@@ -1,5 +1,6 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2014 The Bitcoin Core developers
+// Copyright (c) 2019      The Hush developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -752,15 +753,11 @@ static void ZC_LoadParams(
     struct timeval tv_start, tv_end;
     float elapsed;
 
-    boost::filesystem::path pk_path = ZC_GetParamsDir() / "sprout-proving.key";
-    boost::filesystem::path vk_path = ZC_GetParamsDir() / "sprout-verifying.key";
     boost::filesystem::path sapling_spend = ZC_GetParamsDir() / "sapling-spend.params";
     boost::filesystem::path sapling_output = ZC_GetParamsDir() / "sapling-output.params";
     boost::filesystem::path sprout_groth16 = ZC_GetParamsDir() / "sprout-groth16.params";
 
     if (!(
-        boost::filesystem::exists(pk_path) &&
-        boost::filesystem::exists(vk_path) &&
         boost::filesystem::exists(sapling_spend) &&
         boost::filesystem::exists(sapling_output) &&
         boost::filesystem::exists(sprout_groth16)
@@ -775,10 +772,10 @@ static void ZC_LoadParams(
         return;
     }
 
-    LogPrintf("Loading verifying key from %s\n", vk_path.string().c_str());
+    //LogPrintf("Loading verifying key from %s\n", vk_path.string().c_str());
     gettimeofday(&tv_start, 0);
 
-    pzcashParams = ZCJoinSplit::Prepared(vk_path.string(), pk_path.string());
+    //pzcashParams = ZCJoinSplit::Prepared(vk_path.string(), pk_path.string());
 
     gettimeofday(&tv_end, 0);
     elapsed = float(tv_end.tv_sec-tv_start.tv_sec) + (tv_end.tv_usec-tv_start.tv_usec)/float(1000000);
@@ -796,6 +793,7 @@ static void ZC_LoadParams(
     LogPrintf("Loading Sapling (Sprout Groth16) parameters from %s\n", sprout_groth16.string().c_str());
     gettimeofday(&tv_start, 0);
 
+    // TODO: Unfortunately there is no way to initialize things without groth16, unless Rust code is modified.
     librustzcash_init_zksnark_params(
         reinterpret_cast<const codeunit*>(sapling_spend_str.c_str()),
         sapling_spend_str.length(),

zcutil/fetch-params.sh

@@ -1,20 +1,21 @@
 #!/bin/bash
+# Copyright 2019 The Hush developers
 
 set -eu
 
+# We do not declare our own location because we can use the params
+# from any other installed coins
 if [[ "$OSTYPE" == "darwin"* ]]; then
     PARAMS_DIR="$HOME/Library/Application Support/ZcashParams"
 else
     PARAMS_DIR="$HOME/.zcash-params"
 fi
 
-SPROUT_PKEY_NAME='sprout-proving.key'
-SPROUT_VKEY_NAME='sprout-verifying.key'
 SAPLING_SPEND_NAME='sapling-spend.params'
 SAPLING_OUTPUT_NAME='sapling-output.params'
 SAPLING_SPROUT_GROTH16_NAME='sprout-groth16.params'
-SPROUT_URL="https://z.cash/downloads"
-SPROUT_IPFS="/ipfs/QmZKKx7Xup7LiAtFRhYsE1M7waXcv9ir9eCECyXAFGxhEo"
+URL="https://z.cash/downloads"
+IPFS="/ipfs/QmZKKx7Xup7LiAtFRhYsE1M7waXcv9ir9eCECyXAFGxhEo"
 
 SHA256CMD="$(command -v sha256sum || echo shasum)"
 SHA256ARGS="$(command -v sha256sum >/dev/null || echo '-a 256')"
@@ -38,15 +39,15 @@ function fetch_wget {
 
     cat <<EOF
 
-Retrieving (wget): $SPROUT_URL/$filename
+Retrieving (wget): $URL/$filename
 EOF
 
     wget \
         --progress=dot:giga \
         --output-document="$dlname" \
         --continue \
         --retry-connrefused --waitretry=3 --timeout=30 \
-        "$SPROUT_URL/$filename"
+        "$URL/$filename"
 }
 
 function fetch_ipfs {
@@ -59,10 +60,10 @@ function fetch_ipfs {
 
     cat <<EOF
 
-Retrieving (ipfs): $SPROUT_IPFS/$filename
+Retrieving (ipfs): $IPFS/$filename
 EOF
 
-    ipfs get --output "$dlname" "$SPROUT_IPFS/$filename"
+    ipfs get --output "$dlname" "$IPFS/$filename"
 }
 
 function fetch_curl {
@@ -75,13 +76,13 @@ function fetch_curl {
 
     cat <<EOF
 
-Retrieving (curl): $SPROUT_URL/$filename
+Retrieving (curl): $URL/$filename
 EOF
 
     curl \
         --output "$dlname" \
         -# -L -C - \
-        "$SPROUT_URL/$filename"
+        "$URL/$filename"
 
 }
 
@@ -159,30 +160,29 @@ function main() {
     || exit_locked_error
 
     cat <<EOF
-Zcash - fetch-params.sh
+Pirate - fetch-params.sh
 
-This script will fetch the Zcash zkSNARK parameters and verify their
-integrity with sha256sum.
+This script will fetch the zkSNARK parameters used in shielded
+transactions and verify their integrity with sha256sum.
 
 If they already exist locally, it will exit now and do nothing else.
 EOF
 
     # Now create PARAMS_DIR and insert a README if necessary:
-    if ! [ -d "$PARAMS_DIR" ]
-    then
+    if ! [ -d "$PARAMS_DIR" ]; then
         mkdir -p "$PARAMS_DIR"
         README_PATH="$PARAMS_DIR/README"
         cat >> "$README_PATH" <<EOF
-This directory stores common Zcash zkSNARK parameters. Note that it is
-distinct from the daemon's -datadir argument because the parameters are
-large and may be shared across multiple distinct -datadir's such as when
-setting up test networks.
+This directory stores common zkSNARK parameters needed for shielded
+transactions. Note that it is distinct from the daemon's -datadir argument
+because the parameters are large and may be shared across multiple distinct
+-datadir's such as when setting up test networks.
 EOF
 
         # This may be the first time the user's run this script, so give
         # them some info, especially about bandwidth usage:
         cat <<EOF
-The parameters are currently just under 911MB in size, so plan accordingly
+The parameters are currently about 750MB, so plan accordingly
 for your bandwidth constraints. If the files are already present and
 have the correct sha256sum, no networking is used.
 
@@ -194,14 +194,11 @@ EOF
 
     cd "$PARAMS_DIR"
 
-    # Sprout parameters:
-    fetch_params "$SPROUT_PKEY_NAME" "$PARAMS_DIR/$SPROUT_PKEY_NAME" "8bc20a7f013b2b58970cddd2e7ea028975c88ae7ceb9259a5344a16bc2c0eef7"
-    fetch_params "$SPROUT_VKEY_NAME" "$PARAMS_DIR/$SPROUT_VKEY_NAME" "4bd498dae0aacfd8e98dc306338d017d9c08dd0918ead18172bd0aec2fc5df82"
-
     # Sapling parameters:
     fetch_params "$SAPLING_SPEND_NAME" "$PARAMS_DIR/$SAPLING_SPEND_NAME" "8e48ffd23abb3a5fd9c5589204f32d9c31285a04b78096ba40a79b75677efc13"
     fetch_params "$SAPLING_OUTPUT_NAME" "$PARAMS_DIR/$SAPLING_OUTPUT_NAME" "2f0ebbcbb9bb0bcffe95a397e7eba89c29eb4dde6191c339db88570e3f3fb0e4"
     fetch_params "$SAPLING_SPROUT_GROTH16_NAME" "$PARAMS_DIR/$SAPLING_SPROUT_GROTH16_NAME" "b685d700c60328498fbde589c8c7c484c722b788b265b72af448a5bf0ee55b50"
+
 }
 
 main