Add scrypt-pkcs#8 export for ASP tool compatibility

Cargo.lock

@@ -243,8 +243,11 @@ dependencies = [
  "indoc",
  "josekit",
  "migrations",
+ "scrypt",
  "sea-orm",
  "sequoia-openpgp",
+ "serde",
+ "serde_json",
  "thiserror",
  "tokio",
 ]
@@ -1446,9 +1449,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.2.0"
+version = "2.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf2a4f498956c7723dc280afc6a37d0dec50b39a29e232c6187ce4503703e8c2"
+checksum = "233cf39063f058ea2caae4091bf4a3ef70a653afbc026f5c4a4135d114e3c177"
 dependencies = [
  "equivalent",
  "hashbrown 0.14.3",
@@ -2055,6 +2058,16 @@ version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "de3145af08024dea9fa9914f381a17b8fc6034dfb00f3a84013f7ff43f29ed4c"
 
+[[package]]
+name = "pbkdf2"
+version = "0.12.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8ed6a7761f76e3b9f92dfb0a60a6a6477c61024b775147ff0973a02653abaf2"
+dependencies = [
+ "digest",
+ "hmac",
+]
+
 [[package]]
 name = "peeking_take_while"
 version = "0.1.2"
@@ -2534,6 +2547,15 @@ version = "1.0.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f98d2aa92eebf49b69786be48e4477826b256916e84a57ff2a4f21923b48eb4c"
 
+[[package]]
+name = "salsa20"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97a22f5af31f73a954c10289c93e8a50cc23d971e80ee446f1f6f7137a088213"
+dependencies = [
+ "cipher",
+]
+
 [[package]]
 name = "same-file"
 version = "1.0.6"
@@ -2558,6 +2580,18 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
+[[package]]
+name = "scrypt"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0516a385866c09368f0b5bcd1caff3366aace790fcd46e2bb032697bb172fd1f"
+dependencies = [
+ "password-hash",
+ "pbkdf2",
+ "salsa20",
+ "sha2",
+]
+
 [[package]]
 name = "sct"
 version = "0.7.1"
@@ -2787,9 +2821,9 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.196"
+version = "1.0.197"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "870026e60fa08c69f064aa766c10f10b1d62db9ccd4d0abb206472bee0ce3b32"
+checksum = "3fb1c873e1b9b056a4dc4c0c198b24c3ffa059243875552b2bd0933b1aee4ce2"
 dependencies = [
  "serde_derive",
 ]
@@ -2806,9 +2840,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.196"
+version = "1.0.197"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "33c85360c95e7d137454dc81d9a4ed2b8efd8fbe19cee57357b32b9771fccb67"
+checksum = "7eb0b34b42edc17f6b7cac84a52a1c5f0e1bb2227e997ca9011ea3dd34e8610b"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2817,9 +2851,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.112"
+version = "1.0.114"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d1bd37ce2324cf3bf85e5a25f96eb4baf0d5aa6eba43e7ae8958870c4ec48ed"
+checksum = "c5f09b1bd632ef549eaa9f60a1f8de742bdbc698e6cee2095fc84dde5f549ae0"
 dependencies = [
  "indexmap",
  "itoa",

Cargo.toml

@@ -31,6 +31,9 @@ sequoia-openpgp = { version = "1.18.0", optional = true }
 josekit = { version = "0.8.5" }
 aes-gcm = "0.10.3"
 migrations = { path = "crates/migrations" }
+scrypt = "0.11.0"
+serde = { version = "1.0.197", features = ["derive"] }
+serde_json = "1.0.114"
 
 [features]
 gpg-compat = ["dep:gpgme", "dep:sequoia-openpgp"]

crates/asp/src/keys/mod.rs

@@ -122,7 +122,7 @@ impl AspKey {
 		Self::from_jwk(key_pair.to_jwk_key_pair())
 	}
 
-	pub fn into_pkcs8(&self) -> Result<String, anyhow::Error> {
+	pub fn into_pkcs8(&self) -> Result<Vec<u8>, anyhow::Error> {
 		// This was done because I couldn't find an easy way to get a PKCS#8 encoded private key from the josekit Jwk struct, so I did the following as a workaround, directly using the openssl library:
 		// 1. Get the josekit EcKeyPair from the Jwk
 		// 2. Convert that to a PEM private key
@@ -142,9 +142,8 @@ impl AspKey {
 		let pem_private = key_pair.to_pem_private_key();
 		let pkey = PKey::private_key_from_pem(&pem_private)?;
 		let pkcs8 = pkey.as_ref().private_key_to_pkcs8()?;
-		let encoded = BASE64_NOPAD.encode(&pkcs8);
 
-		Ok(encoded)
+		Ok(pkcs8)
 	}
 
 	pub fn generate(key_type: AspKeyType) -> Result<Self, anyhow::Error> {

src/commands/keys/export.rs

@@ -1,5 +1,5 @@
 use aes_gcm::{
-	aead::{Aead, KeyInit},
+	aead::{rand_core::RngCore, Aead, KeyInit, OsRng},
 	Aes256Gcm, Key,
 };
 use anstyle::{AnsiColor, Color as AnstyleColor, Reset, Style as Anstyle};
@@ -7,10 +7,11 @@ use anyhow::{anyhow, Context};
 use argon2::{password_hash::SaltString, Argon2, PasswordHasher};
 use asp::keys::AspKey;
 use clap::{Parser, ValueEnum};
-use data_encoding::BASE64_NOPAD;
+use data_encoding::{BASE64, BASE64_NOPAD};
 use dialoguer::{theme::ColorfulTheme, Password};
 use indoc::writedoc;
 use josekit::jwk::Jwk;
+use serde::Serialize;
 
 use std::io::Write;
 
@@ -19,12 +20,35 @@ use crate::{
 	entities::prelude::*,
 };
 
+#[derive(Serialize)]
+#[serde(tag = "alg", rename = "scrypt")]
+pub struct ASPToolScryptExport {
+	#[serde(rename = "prm")]
+	parameters: ASPToolScryptExportParam,
+	#[serde(rename = "slt")]
+	salt: String,
+	#[serde(rename = "key")]
+	encrypted_key: String,
+}
+
+#[derive(Serialize)]
+pub struct ASPToolScryptExportParam {
+	#[serde(rename = "N")]
+	cost: u64,
+	#[serde(rename = "r")]
+	block_size: u32,
+	#[serde(rename = "p")]
+	parallelism: u32,
+}
+
 #[derive(ValueEnum, Debug, Clone)]
 pub enum KeyExportFormat {
-	/// An unencrypted PKCS#8 format. This is the format used by the asp.keyoxide.org web tool.
+	/// An unencrypted PKCS#8 format.
 	#[clap(alias = "PKCS#8")]
 	PKCS8,
-	/// An unencrypted raw JSON Web Key format. This is likely not the best output to use unless you know what you are doing.
+	/// An scrypt-encrypted PKCS#8 key, formatted for the asp.keyoxide.org web tool. The password on the exported key is the same as the one used for ASPM.
+	ASPTool,
+	/// An unencrypted raw JSON Web Key (JWK) format.
 	Jwk,
 }
 
@@ -92,10 +116,52 @@ impl AspmSubcommand for KeysExportCommand {
 			let decrypted = AspKey::from_jwk(Jwk::from_bytes(decrypted)?)?;
 
 			let export = match self.format {
-				KeyExportFormat::PKCS8 => decrypted
-					.into_pkcs8()
-					.context("Unable to convert key into PKCS#8 format")?,
 				KeyExportFormat::Jwk => decrypted.jwk.to_string(),
+				KeyExportFormat::PKCS8 => BASE64_NOPAD.encode(
+					decrypted
+						.into_pkcs8()
+						.context("Unable to convert key into PKCS#8 format")?
+						.as_slice(),
+				),
+				KeyExportFormat::ASPTool => {
+					let pkcs8 = decrypted
+						.into_pkcs8()
+						.context("Unable to convert key into PKCS#8 format")?;
+					let mut salt = [0u8; 16];
+					OsRng.fill_bytes(&mut salt);
+
+					let mut derived_key = vec![0u8; pkcs8.len()];
+					scrypt::scrypt(
+						key_password.as_bytes(),
+						&salt,
+						&scrypt::Params::recommended(),
+						&mut derived_key,
+					)
+					.context("Unable to derive PKCS#8 encryption key with scrypt")?;
+
+					let encrypted_key = BASE64.encode(
+						pkcs8
+							.into_iter()
+							.enumerate()
+							.map(|(i, byte)| byte ^ derived_key[i])
+							.collect::<Vec<_>>()
+							.as_slice(),
+					);
+
+					BASE64.encode(
+						serde_json::to_string(&ASPToolScryptExport {
+							parameters: ASPToolScryptExportParam {
+								cost: 1 << scrypt::Params::RECOMMENDED_LOG_N,
+								block_size: scrypt::Params::RECOMMENDED_R,
+								parallelism: scrypt::Params::RECOMMENDED_P,
+							},
+							salt: BASE64.encode(&salt),
+							encrypted_key,
+						})
+						.context("Unable to construct JSON form of ASPTool export")?
+						.as_bytes(),
+					)
+				}
 			};
 
 			eprintln!(

src/commands/keys/import.rs

@@ -158,48 +158,42 @@ impl AspmSubcommand for KeysImportCommand {
 				let public_part = key.mpis();
 
 				let (curve, public, secret) = match key.secret() {
-					key::SecretKeyMaterial::Unencrypted(data) => {
-						data.map(|secret_material| {
-							let (curve, public, private) = match secret_material {
-								mpi::SecretKeyMaterial::ECDSA { scalar } => {
-									let mpi::PublicKey::ECDSA {
-										curve,
-										q: public_part,
-									} = public_part
-									else {
-										unreachable!()
-									};
-	
-									(curve, public_part, scalar)
-								},
-								mpi::SecretKeyMaterial::EdDSA { scalar } => {
-									let mpi::PublicKey::EdDSA {
-										curve,
-										q: public_part,
-									} = public_part
-									else {
-										unreachable!()
-									};
-	
-									(curve, public_part, scalar)
-								},
-								_ => bail!("Invalid PGP key type, must be either P-256 or Ed25519")
-							};
+					key::SecretKeyMaterial::Unencrypted(data) => data.map(|secret_material| {
+						let (curve, public, private) = match secret_material {
+							mpi::SecretKeyMaterial::ECDSA { scalar } => {
+								let mpi::PublicKey::ECDSA {
+									curve,
+									q: public_part,
+								} = public_part
+								else {
+									unreachable!()
+								};
 
-							Ok((
-								curve.clone(),
-								public.clone(),
-								private.clone()
-							))
-						})?
-					}
+								(curve, public_part, scalar)
+							}
+							mpi::SecretKeyMaterial::EdDSA { scalar } => {
+								let mpi::PublicKey::EdDSA {
+									curve,
+									q: public_part,
+								} = public_part
+								else {
+									unreachable!()
+								};
+
+								(curve, public_part, scalar)
+							}
+							_ => bail!("Invalid PGP key type, must be either P-256 or Ed25519"),
+						};
+
+						Ok((curve.clone(), public.clone(), private.clone()))
+					})?,
 					_ => unreachable!(),
 				};
 
 				AspKey::from_jwk(
 					Jwk::from_map({
 						let mut map = josekit::Map::new();
-						
+
 						match curve {
 							Curve::Ed25519 => {
 								map.insert("kty".to_string(), "OKP".into());
@@ -237,7 +231,8 @@ impl AspmSubcommand for KeysImportCommand {
 						}
 
 						map
-					}).context("Unable to construct Jwk representation of PGP key")?
+					})
+					.context("Unable to construct Jwk representation of PGP key")?,
 				)?
 			}
 		};