fix: Strengthen scrypt parameters

docs/cli-reference/quill-generate.mdx

@@ -69,6 +69,6 @@ Most `quill` commands take a `--pem-file` parameter, for the key used to sign th
 
 If a password-protected key needs to be exported for use with another tool such as DFX, use [`quill decrypt-pem`].
 
-Technical notes: Passwords are run through `scrypt(r=8,p=1,n=131072,len=32)`, and then the file is encrypted with AES-256-CBC.
+Technical notes: Passwords are run through `scrypt(r=8,p=1,n=2^17,len=32)`, and then the file is encrypted with AES-256-CBC.
 
 [`quill decrypt-pem`]: quill-decrypt-pem.mdx

src/commands/generate.rs

@@ -1,15 +1,15 @@
 use crate::{
-    lib::{get_account_id, mnemonic_to_key, AnyhowResult},
+    lib::{get_account_id, key_encryption_params, mnemonic_to_key, AnyhowResult},
     read_file,
 };
 use anyhow::{anyhow, bail, Context};
 use bip39::{Language, Mnemonic};
 use clap::{Parser, ValueEnum};
 use dialoguer::Password;
 use ic_agent::{identity::Secp256k1Identity, Identity};
-use pkcs8::EncodePrivateKey;
+use pkcs8::{EncodePrivateKey, EncryptedPrivateKeyInfo, PrivateKeyInfo};
 use rand::{rngs::OsRng, thread_rng, RngCore};
-use sec1::LineEnding;
+use sec1::{pem::PemLabel, LineEnding};
 use std::{
     io::{stdin, IsTerminal},
     path::PathBuf,
@@ -122,7 +122,15 @@ Copy this onto a piece of paper or external media and store it in a safe place."
                     .with_confirmation("Re-enter password", "Passwords did not match")
                     .interact()?
             };
-            key.to_pkcs8_encrypted_pem(thread_rng(), password, LineEnding::default())?
+            let key_der = key.to_pkcs8_der()?;
+            let pki = PrivateKeyInfo::try_from(key_der.as_bytes())?;
+            let mut rng = thread_rng();
+            let mut salt = [0u8; 16];
+            rng.fill_bytes(&mut salt);
+            let mut iv = [0u8; 16];
+            rng.fill_bytes(&mut iv);
+            let doc = pki.encrypt_with_params(key_encryption_params(&salt, &iv), password)?;
+            doc.to_pem(EncryptedPrivateKeyInfo::PEM_LABEL, LineEnding::default())?
         }
     };
     std::fs::write(&opts.pem_file, &pem)?;

src/lib/mod.rs

@@ -22,6 +22,7 @@ use ic_nns_constants::{
 use icp_ledger::{AccountIdentifier, Subaccount};
 use icrc_ledger_types::icrc1::account::Account;
 use k256::SecretKey;
+use pkcs8::pkcs5::{pbes2::Parameters, scrypt::Params};
 use ring::signature::Ed25519KeyPair;
 use serde_cbor::Value;
 
@@ -610,6 +611,12 @@ pub fn e8s_to_tokens(e8s: Nat) -> BigDecimal {
     BigDecimal::new(e8s.0.into(), 8)
 }
 
+pub fn key_encryption_params<'a>(salt: &'a [u8; 16], iv: &'a [u8; 16]) -> Parameters<'a> {
+    let scrypt_params = Params::new(17, 8, 1, 32).expect("valid scrypt Params consts");
+    Parameters::scrypt_aes256cbc(scrypt_params, salt, iv)
+        .expect("valid PKCS5 encryption parameters")
+}
+
 #[cfg(test)]
 mod tests {
     use super::{ParsedAccount, ParsedSubaccount};