Add tool for splitting parameters up into separate files, for Zcash

Cargo.toml

@@ -17,6 +17,9 @@ name = "compute"
 [[bin]]
 name = "verify_transform"
 
+[[bin]]
+name = "split_params"
+
 [dependencies]
 phase2 = "0.2.1"
 pairing = "0.14"

src/bin/split_params.rs

@@ -0,0 +1,44 @@
+//! This binary just splits the parameters up into separate files.
+
+extern crate phase2;
+extern crate pairing;
+extern crate rand;
+extern crate blake2_rfc;
+
+use std::fs::File;
+use std::io::{BufWriter, BufReader};
+
+fn main() {
+    let current_params = File::open("params").expect("couldn't open `./params`");
+    let mut current_params = BufReader::with_capacity(1024*1024, current_params);
+
+    let sapling_spend = phase2::MPCParameters::read(&mut current_params, false)
+        .expect("couldn't deserialize Sapling Spend params");
+
+    let sapling_output = phase2::MPCParameters::read(&mut current_params, false)
+        .expect("couldn't deserialize Sapling Output params");
+
+    let sprout_joinsplit = phase2::MPCParameters::read(&mut current_params, false)
+        .expect("couldn't deserialize Sprout JoinSplit params");
+
+    {
+        let f = File::create("sapling-spend.params").expect("couldn't create `./sapling-spend.params`");
+        let mut f = BufWriter::with_capacity(1024*1024, f);
+        sapling_spend.write(&mut f)
+            .expect("couldn't write new Sapling Spend params");
+    }
+
+    {
+        let f = File::create("sapling-output.params").expect("couldn't create `./sapling-output.params`");
+        let mut f = BufWriter::with_capacity(1024*1024, f);
+        sapling_output.write(&mut f)
+            .expect("couldn't write new Sapling Output params");
+    }
+
+    {
+        let f = File::create("sprout-groth16.params").expect("couldn't create `./sapling-groth16.params`");
+        let mut f = BufWriter::with_capacity(1024*1024, f);
+        sprout_joinsplit.write(&mut f)
+            .expect("couldn't write new Sprout JoinSplit params");
+    }
+}