Add user entropy

5 years ago · 0ad84fd146
3 changed files with 71 additions and 32 deletions
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@ -32,10 +32,14 @@ fn main() {
                .long("output")
                .index(1)
                .help("Name of output file."))
+        .arg(Arg::with_name("entropy")
+                .short("e")
+                .long("entropy")
+                .help("Provide additional entropy to the random number generator. Any random string, containing 32-64 characters"))
        .arg(Arg::with_name("z_addresses")
                .short("z")
-                .long("z_addresses")
-                .help("Number of Z addresses (sapling) to generate")
+                .long("zaddrs")
+                .help("Number of Z addresses (Sapling) to generate")
                .takes_value(true)
                .default_value("1")                
                .validator(|i:String| match i.parse::<i32>() {
@ -48,6 +52,23 @@ fn main() {
    
    let nohd: bool    = matches.is_present("nohd");

+    // Get user entropy. 
+    let mut entropy: Vec<u8> = Vec::new();
+    // If the user hasn't specified any, read from the stdin
+    if matches.value_of("entropy").is_none() {
+        // Read from stdin
+        println!("Provide additional entropy for generating random numbers. Type in a string of random characters, press [ENTER] when done");
+        let mut buffer = String::new();
+        let stdin = io::stdin();
+        stdin.lock().read_line(&mut buffer).unwrap();
+
+        entropy.extend_from_slice(buffer.as_bytes());
+    } else {
+        // Use provided entropy. 
+        entropy.extend(matches.value_of("entropy").unwrap().as_bytes());
+    }
+
+    // Get the filename and output format
    let filename = matches.value_of("output");
    let format   = matches.value_of("format").unwrap();

@ -57,11 +78,12 @@ fn main() {
        return;
    }

-    let num_addresses = matches.value_of("z_addresses").unwrap().parse::<u32>().unwrap();
+    // Number of z addresses to generate
+    let num_addresses = matches.value_of("z_addresses").unwrap().parse::<u32>().unwrap();    

    print!("Generating {} Sapling addresses.........", num_addresses);
    io::stdout().flush().ok();
-    let addresses = generate_wallet(testnet, nohd, num_addresses); 
+    let addresses = generate_wallet(testnet, nohd, num_addresses, &entropy); 
    println!("[OK]");
    
    // If the default format is present, write to the console if the filename is absent
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@ -5,19 +5,20 @@ authors = ["ZecWallet"]
 edition = "2018"

 [dependencies]
-bech32 = "0.6"
-bellman = { git = "https://github.com/zcash/librustzcash" }
-ff = { git = "https://github.com/zcash/librustzcash"  }
-hex = "0.3"
-pairing = { git = "https://github.com/zcash/librustzcash" }
-protobuf = "2"
 rand = "0.5"
-rusqlite = { version = "0.15", features = ["bundled"], optional = true }
-sapling-crypto = {  git = "https://github.com/zcash/librustzcash" }
-time = { version = "0.1", optional = true }
-zcash_primitives = {  git = "https://github.com/zcash/librustzcash" }
-zcash_proofs = {  git = "https://github.com/zcash/librustzcash" }
-zip32 = {  git = "https://github.com/zcash/librustzcash" }
+hex = "0.3"
+bech32 = "0.6"
+bellman = { git = "https://github.com/zcash/librustzcash", rev="3b6f5e3d5ede6469f6ae85357f0b03d4c1b45cfe" }
+ff = { git = "https://github.com/zcash/librustzcash", rev="3b6f5e3d5ede6469f6ae85357f0b03d4c1b45cfe" }
+
+pairing = { git = "https://github.com/zcash/librustzcash", rev="3b6f5e3d5ede6469f6ae85357f0b03d4c1b45cfe" }
+
+sapling-crypto = {  git = "https://github.com/zcash/librustzcash", rev="3b6f5e3d5ede6469f6ae85357f0b03d4c1b45cfe" }
+
+zcash_primitives = {  git = "https://github.com/zcash/librustzcash", rev="3b6f5e3d5ede6469f6ae85357f0b03d4c1b45cfe" }
+zcash_proofs = {  git = "https://github.com/zcash/librustzcash", rev="3b6f5e3d5ede6469f6ae85357f0b03d4c1b45cfe" }
+zip32 = {  git = "https://github.com/zcash/librustzcash", rev="3b6f5e3d5ede6469f6ae85357f0b03d4c1b45cfe" }
 json = "0.11.14"    
 qrcode = { version = "0.8", default-features = false }
-printpdf = "0.2.8"
+printpdf = "0.2.8"
+blake2-rfc = { git = "https://github.com/gtank/blake2-rfc", rev="7a5b5fc99ae483a0043db7547fb79a6fa44b88a9" }
--- a/lib/src/paper.rs
+++ b/lib/src/paper.rs
@ -1,25 +1,41 @@

 use zip32::{ChildIndex, ExtendedSpendingKey};
 use bech32::{Bech32, u5, ToBase32};
-use rand::{Rng, ChaChaRng, FromEntropy};
+use rand::{Rng, ChaChaRng, FromEntropy, SeedableRng};
 use json::{array, object};
+use blake2_rfc::blake2b::Blake2b;

 /**
 * Generate a series of `count` addresses and private keys. 
 */
-pub fn generate_wallet(testnet: bool, nohd: bool, count: u32) -> String {    
+pub fn generate_wallet(testnet: bool, nohd: bool, count: u32, user_entropy: &[u8]) -> String {        
+    // Get 32 bytes of system entropy
+    let mut system_entropy:[u8; 32] = [0; 32]; 
+    {
+        let mut system_rng = ChaChaRng::from_entropy();    
+        system_rng.fill(&mut system_entropy);
+    }
+
+    // Add in user entropy to the system entropy, and produce a 32 byte hash... 
+    let mut state = Blake2b::new(32);
+    state.update(&system_entropy);
+    state.update(&user_entropy);
+    
+    let mut final_entropy: [u8; 32] = [0; 32];
+    final_entropy.clone_from_slice(&state.finalize().as_bytes()[0..32]);
+
+    // ...which will we use to seed the RNG
+    let mut rng = ChaChaRng::from_seed(final_entropy);
+
    if !nohd {
-        // Allow HD addresses, so use only 1 seed
-        let mut rng = ChaChaRng::from_entropy();
-        let mut seed:[u8; 32] = [0; 32]; 
+        // Allow HD addresses, so use only 1 seed        
+        let mut seed: [u8; 32] = [0; 32];
        rng.fill(&mut seed);
        
        return gen_addresses_with_seed_as_json(testnet, count, |i| (seed.to_vec(), i));
    } else {
-        // Not using HD addresses, so derive a new seed every time
-
-        return gen_addresses_with_seed_as_json(testnet, count, |_| {
-            let mut rng = ChaChaRng::from_entropy();
+        // Not using HD addresses, so derive a new seed every time    
+        return gen_addresses_with_seed_as_json(testnet, count, |_| {            
            let mut seed:[u8; 32] = [0; 32]; 
            rng.fill(&mut seed);
            
@ -39,8 +55,8 @@ pub fn generate_wallet(testnet: bool, nohd: bool, count: u32) -> String {
 *
 * It is useful if we want to reuse (or not) the seed across multiple wallets.
 */
-fn gen_addresses_with_seed_as_json<F>(testnet: bool, count: u32, get_seed: F) -> String 
-    where F: Fn(u32) -> (Vec<u8>, u32)
+fn gen_addresses_with_seed_as_json<F>(testnet: bool, count: u32, mut get_seed: F) -> String 
+    where F: FnMut(u32) -> (Vec<u8>, u32)
 {
    let mut ans = array![];

@ -113,7 +129,7 @@ mod tests {
        use std::collections::HashSet;
        
        // Testnet wallet
-        let w = generate_wallet(true, false, 1);
+        let w = generate_wallet(true, false, 1, &[]);
        let j = json::parse(&w).unwrap();
        assert_eq!(j.len(), 1);
        assert!(j[0]["address"].as_str().unwrap().starts_with("ztestsapling"));
@ -122,7 +138,7 @@ mod tests {


        // Mainnet wallet
-        let w = generate_wallet(false, false, 1);
+        let w = generate_wallet(false, false, 1, &[]);
        let j = json::parse(&w).unwrap();
        assert_eq!(j.len(), 1);
        assert!(j[0]["address"].as_str().unwrap().starts_with("zs"));
@ -130,7 +146,7 @@ mod tests {
        assert_eq!(j[0]["seed"]["path"].as_str().unwrap(), "m/32'/133'/0'");

        // Check if all the addresses are the same
-        let w = generate_wallet(true, false, 3);
+        let w = generate_wallet(true, false, 3, &[]);
        let j = json::parse(&w).unwrap();
        assert_eq!(j.len(), 3);

@ -161,7 +177,7 @@ mod tests {
        use std::collections::HashSet;
        
        // Check if all the addresses use a different seed
-        let w = generate_wallet(true, true, 3);
+        let w = generate_wallet(true, true, 3, &[]);
        let j = json::parse(&w).unwrap();
        assert_eq!(j.len(), 3);