How to create multiple wallets, also known HD wallets with rust code?

Question

I tried to implement the example from the cookbook, but I made a mistake somewhere. Or I misunderstood something https://solanacookbook.com/references/keypairs-and-wallets.html#how-to-restore-a-keypair-from-a-mnemonic-phrase

[dependencies]
bip39 = { version = "2.0.0", features = ["rand"] }
derivation-path = "0.2.0"
hdpath = "0.6.3"
slip10 = "0.4.3"
solana-sdk = { version = "2.0.8", features = ["curve25519-dalek"] }
tiny-hderive = "0.3.0"

main.rs

use bip39::{Language, Mnemonic};
// use derivation_path::{ChildIndex, DerivationPath};
use solana_sdk::derivation_path::DerivationPath;
use solana_sdk::signature::SeedDerivable;
use solana_sdk::signature::{Keypair, Signer};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mnemonic = "neither lonely flavor argue grass remind eye tag avocado spot unusual intact";
    let mnemonic = Mnemonic::parse_in_normalized(Language::English, mnemonic)?;
    let seed = mnemonic.to_seed("");

    for i in 0..10 {
        let path = format!("m/44'/501'/{}'/0'", i);
        println!("{}", path);
        let der_path = DerivationPath::try_from(path.as_str()).unwrap();

        // let master = ExtendedPrivKey::derive(&seed, der_path).unwrap();
        // let derived = master.derive(&path);
        // let secret = SecretKey::from_bytes(&derived.secret())?;
        let keypair = Keypair::from_seed_and_derivation_path(&seed, Some(der_path)).unwrap();
        // let keypair = Keypair::from_bytes(&master)?;
        let pubkey = keypair.pubkey();

        println!("{} => {}", path, pubkey);
    }

    Ok(())
}

Answer 1

The best practice for readers to be able to help is to provide the error that is thrown by the code.

With this, I believe it will be

called `Result::unwrap()` on an `Err` value: InvalidDerivationPath("invalid child index: could not parse child index: invalid digit found in string")

When expecting to get a Rust stack trace of the error with export RUST_BACKTRACE=full we can see the error is thrown from the try_from call at Solana SDK https://github.com/anza-xyz/agave/blob/v2.0.9/sdk/src/derivation_path.rs#L53

That method calls into https://github.com/anza-xyz/agave/blob/v2.0.9/sdk/src/derivation_path.rs#L69

where the API expects the coin (https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki#path-levels) to be provided explicitly being Solana. The solution could be to strip the path from m'/44'/501/' or switch to method DerivationPath::from_absolute_path_str.

with the use of

let path = format!("{}'/0'", i);
let derivation_path = DerivationPath::try_from(path.as_str()).unwrap();

the code seems to be working well

0'/0' => 5vftMkHL72JaJG6ExQfGAsT2uGVHpRR7oTNUPMs68Y2N
1'/0' => GcXbfQ5yY3uxCyBNDPBbR5FjumHf89E7YHXuULfGDBBv
2'/0' => 7QPgyQwNLqnoSwHEuK8wKy2Y3Ani6EHoZRihTuWkwxbc
3'/0' => 5aE8UprEEWtpVskhxo3f8ETco2kVKiZT9SS3D5Lcg8s2
4'/0' => 5n6afo6LZmzH1J4R38ZCaNSwaztLjd48nWwToLQkCHxp
5'/0' => 2Gr1hWnbaqGXMghicSTHncqV7GVLLddNFJDC7YJoso8M
6'/0' => BNMDY3tCyYbayMzBjZm8RW59unpDWcQRfVmWXCJhLb7D
7'/0' => 9CySTpi4iC85gMW6G4BMoYbNBsdyJrfseHoGmViLha63
8'/0' => ApteF7PmUWS8Lzm6tJPkWgrxSFW5LwYGWCUJ2ByAec91
9'/0' => 6frdqXQAgJMyKwmZxkLYbdGjnYTvUceh6LNhkQt2siQp