Add seed phrases

rust-lightclient/Cargo.toml

@@ -23,6 +23,8 @@ rustyline = "5.0.2"
 byteorder = "1"
 rand = "0.5.6"
 json = "0.12.0"
+bip39 = "0.6.0-beta.1"
+clap = "2.33"
 
 [dependencies.bellman]
 path = "../../librustzcash/bellman"

rust-lightclient/src/commands.rs

@@ -110,18 +110,23 @@ impl Command for SaveCommand {
     }
 }
 
-struct ReadCommand {}
-impl Command for ReadCommand {
-        fn help(&self) {
-        println!("Read wallet from disk");
+struct SeedCommand {}
+impl Command for SeedCommand {
+    fn help(&self) {
+        println!("Show the seed phrase for the wallet");
     }
 
     fn short_help(&self) -> String {
-        "Read wallet file from disk".to_string()
+        "Display the seed phrase".to_string()
     }
 
     fn exec(&self, _args: &[String], lightclient: &mut LightClient) {
-        lightclient.do_read();
+        let phrase = lightclient.do_seed_phrase();
+
+        println!("Current seed phrase. PLEASE SAVE THIS CAREFULLY AND DO NOT SHARE IT");
+        println!();
+        println!("{}", phrase);
+        println!();
     }
 }
 
@@ -167,9 +172,9 @@ pub fn get_commands() -> Box<HashMap<String, Box<dyn Command>>> {
     map.insert("info".to_string(),      Box::new(InfoCommand{}));
     map.insert("send".to_string(),      Box::new(SendCommand{}));
     map.insert("save".to_string(),      Box::new(SaveCommand{}));
-    map.insert("read".to_string(),      Box::new(ReadCommand{}));
     map.insert("quit".to_string(),      Box::new(QuitCommand{}));
     map.insert("list".to_string(),      Box::new(TransactionsCommand{}));
+    map.insert("seed".to_string(),      Box::new(SeedCommand{}));
 
     Box::new(map)
 }

rust-lightclient/src/lightclient.rs

@@ -39,24 +39,44 @@ pub struct LightClient {
 }
 
 impl LightClient {
-    pub fn new() -> Self {
-        let mut w = LightClient {
-            wallet          : Arc::new(LightWallet::new()), 
-            sapling_output  : vec![], 
-            sapling_spend   : vec![]
-        };
+    pub fn new(seed_phrase: Option<&str>) -> io::Result<Self> {
 
-        // Read Sapling Params
-        let mut f = File::open("/home/adityapk/.zcash-params/sapling-output.params").unwrap();
-        f.read_to_end(&mut w.sapling_output).unwrap();
-        let mut f = File::open("/home/adityapk/.zcash-params/sapling-spend.params").unwrap();
-        f.read_to_end(&mut w.sapling_spend).unwrap();
+        let mut lc = if Path::new("wallet.dat").exists() {
+            // Make sure that if a wallet exists, there is no seed phrase being attempted
+            if !seed_phrase.is_none() {
+                return Err(io::Error::new(io::ErrorKind::AlreadyExists,
+                    "Cannot restore from seed, because a wallet already exists"));
+            }
+
+            let mut file_buffer = BufReader::new(File::open("wallet.dat")?);
+            
+            let wallet = LightWallet::read(&mut file_buffer)?;
+             LightClient {
+                wallet          : Arc::new(wallet), 
+                sapling_output  : vec![], 
+                sapling_spend   : vec![]
+            }
+        } else {
+            let l = LightClient {
+                wallet          : Arc::new(LightWallet::new(seed_phrase).unwrap()), 
+                sapling_output  : vec![], 
+                sapling_spend   : vec![]
+            };
 
-        w.wallet.set_initial_block(500000,
-                            "004fada8d4dbc5e80b13522d2c6bd0116113c9b7197f0c6be69bc7a62f2824cd",
-                            "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");
+            l.wallet.set_initial_block(500000,
+                "004fada8d4dbc5e80b13522d2c6bd0116113c9b7197f0c6be69bc7a62f2824cd",
+                "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");
 
-        return w;
+            l
+        };
+        
+        // Read Sapling Params
+        let mut f = File::open("/home/adityapk/.zcash-params/sapling-output.params")?;
+        f.read_to_end(&mut lc.sapling_output)?;
+        let mut f = File::open("/home/adityapk/.zcash-params/sapling-spend.params")?;
+        f.read_to_end(&mut lc.sapling_spend)?;
+
+        Ok(lc)
     }
 
     pub fn last_scanned_height(&self) -> u64 {
@@ -80,27 +100,6 @@ impl LightClient {
         }
     }
 
-    pub fn do_read(&mut self) {
-        if !Path::new("wallet.dat").exists() {
-            println!("No existing wallet");
-            return;
-        }
-
-        print!("Reading wallet...");
-        io::stdout().flush().ok().expect("Could not flush stdout");
-        let mut file_buffer = match File::open("wallet.dat") {
-            Ok(f)  => BufReader::new(f),
-            Err(e) => {
-                println!("[Error: {}]", e.description());
-                return;
-            }
-        };
-        
-        let lw = LightWallet::read(&mut file_buffer).unwrap();
-        self.wallet = Arc::new(lw);
-        println!("[OK]");
-    }
-
     pub fn do_save(&self) {
         print!("Saving wallet...");
         io::stdout().flush().ok().expect("Could not flush stdout");
@@ -133,6 +132,10 @@ impl LightClient {
         tokio::runtime::current_thread::Runtime::new().unwrap().block_on(say_hello).unwrap()
     }
 
+    pub fn do_seed_phrase(&self) -> String {
+        self.wallet.get_seed_phrase()
+    }
+
     pub fn do_list_transactions(&self) -> JsonValue {
         // Create a list of TransactionItems
         let mut tx_list = self.wallet.txs.read().unwrap().iter()
@@ -168,14 +171,14 @@ impl LightClient {
                             "amount"       => nd.note.value as i64,
                             "address"      => nd.note_address().unwrap(),
                             "memo"         => match &nd.memo {
-                                            Some(memo) => {
-                                                match memo.to_utf8() {
-                                                    Some(Ok(memo_str)) => Some(memo_str),
-                                                    _ => None
+                                                Some(memo) => {
+                                                    match memo.to_utf8() {
+                                                        Some(Ok(memo_str)) => Some(memo_str),
+                                                        _ => None
+                                                    }
                                                 }
+                                                _ => None
                                             }
-                                            _ => None
-                                        }
                     })
                 );
 

rust-lightclient/src/lightwallet.rs

@@ -6,7 +6,9 @@ use std::cmp;
 use std::collections::HashMap;
 use std::sync::{Arc, RwLock};
 
-use protobuf::*;
+use protobuf::parse_from_bytes;
+
+use bip39::{Mnemonic, Language};
 
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use pairing::bls12_381::{Bls12};
@@ -383,27 +385,33 @@ impl LightWallet {
         (extsk, extfvk, address)
     }
 
-    pub fn new() -> Self {
+    pub fn new(seed_phrase: Option<&str>) -> io::Result<Self> {
         use rand::{FromEntropy, ChaChaRng, Rng};
 
-        // Create a random seed. 
-        let mut system_rng = ChaChaRng::from_entropy();
         let mut seed_bytes = [0u8; 32];
-        system_rng.fill(&mut seed_bytes);
+
+        if seed_phrase.is_none() {
+            // Create a random seed. 
+            let mut system_rng = ChaChaRng::from_entropy();
+            system_rng.fill(&mut seed_bytes);
+        } else {
+            seed_bytes.copy_from_slice(&Mnemonic::from_phrase(seed_phrase.expect("should have a seed phrase"), 
+                                        Language::English).unwrap().entropy());
+        }
 
         // Derive only the first address
         // TODO: We need to monitor addresses, and always keep 1 "free" address, so 
         // users can import a seed phrase and automatically get all used addresses
         let (extsk, extfvk, address) = LightWallet::get_pk_from_seed(&seed_bytes);
 
-        LightWallet {
+        Ok(LightWallet {
             seed:    seed_bytes,
             extsks:  vec![extsk],
             extfvks: vec![extfvk],
             address: vec![address],
             blocks:  Arc::new(RwLock::new(vec![])),
             txs:     Arc::new(RwLock::new(HashMap::new())),
-        }
+        })
     }
 
     pub fn read<R: Read>(mut reader: R) -> io::Result<Self> {
@@ -539,6 +547,12 @@ impl LightWallet {
         encode_payment_address(HRP_SAPLING_PAYMENT_ADDRESS, &self.address[account])
     }
 
+    pub fn get_seed_phrase(&self) -> String {
+        Mnemonic::from_entropy(&self.seed, 
+                                Language::English,
+        ).unwrap().phrase().to_string()
+    }
+
     pub fn balance(&self, addr: Option<String>) -> u64 {
         self.txs
             .read()

rust-lightclient/src/main.rs

@@ -16,8 +16,21 @@ pub mod grpc_client {
 
 
 pub fn main() {
+    use clap::{Arg, App};
+
+    let matches = App::new("Light Client")
+                    .version("1.0") 
+                    .arg(Arg::with_name("seed")
+                        .short("s")
+                        .long("seed")
+                        .value_name("seed_phrase")
+                        .help("Create a new wallet with the given 24-word seed phrase. Will fail if wallet already exists")
+                        .takes_value(true))
+                    .get_matches();
+
+    let mut lightclient = LightClient::new(matches.value_of("seed")).unwrap();
+
     println!("Starting Light Client");
-    let mut lightclient = LightClient::new();
 
     // At startup, read the wallet.dat 
     commands::do_user_command(&"read".to_string(), &mut lightclient);