Add more configuration (#103)

.cspell.jsonc

@@ -22,6 +22,7 @@
     "secp",
     "secp256k1",
     "ssse",
+    "struct",
     "symm",
     "typenum"
   ],

.github/dependabot.yml

@@ -3,5 +3,5 @@ updates:
 - package-ecosystem: cargo
   directory: "/"
   schedule:
-    interval: daily
+    interval: monthly
   open-pull-requests-limit: 10

CHANGELOG.md

@@ -0,0 +1,24 @@
+# Changelog
+
+## 0.2.1 ~ 0.2.4
+
+- Add configuration for more compatibility
+- Revamp error handling
+- Migrate to edition 2021
+- Bump dependencies
+
+## 0.2.0
+
+- Revamp documentation
+- Optional pure Rust AES backend
+- WASM compatibility
+
+## 0.1.1 ~ 0.1.5
+
+- Bump dependencies
+- Update documentation
+- Fix error handling
+
+## 0.1.0
+
+- First beta version release

Cargo.toml

@@ -42,6 +42,8 @@ rand = {version = "0.8.5"}
 [features]
 default = ["openssl"]
 pure = ["aes-gcm", "typenum"]
+# default: 16 bytes
+aes_12bytes_nonce = []
 
 [dev-dependencies]
 criterion = {version = "0.5.1", default-features = false}

README.md

@@ -133,26 +133,38 @@ Found 1 outliers among 10 measurements (10.00%)
   1 (10.00%) high mild
 ```
 
-## Release Notes
+## Configuration
 
-### 0.2.1 ~ 0.2.4
+You can enable 12 bytes nonce by specify `aes_12bytes_nonce` feature.
 
-- Revamp error handling
-- Migrate to edition 2021
-- Bump dependencies
+```toml
+ecies = {version = "0.2", default-features = false, features = ["aes_12bytes_nonce"]}
+```
+
+Other behaviors can be configured by global static variable:
 
-### 0.2.0
+```rs
+pub struct Config {
+    pub is_ephemeral_key_compressed: bool,
+    pub is_hkdf_key_compressed: bool,
+    pub symmetric_algorithm: SymmetricAlgorithm,
+}
+```
+
+If you set `is_ephemeral_key_compressed: true`, the payload would be like: `33 Bytes + AES` instead of `65 Bytes + AES`.
 
-- Revamp documentation
-- Optional pure Rust AES backend
-- WASM compatibility
+If you set `is_hkdf_key_compressed: true`, the hkdf key would be derived from `ephemeral public key (compressed) + shared public key (compressed)` instead of `ephemeral public key (uncompressed) + shared public key (uncompressed)`.
 
-### 0.1.1 ~ 0.1.5
+```rs
+update_config(Config {
+    is_ephemeral_key_compressed: true,
+    is_hkdf_key_compressed: true,
+    ..Config::default()
+});
+```
 
-- Bump dependencies
-- Update documentation
-- Fix error handling
+For compatibility, make sure different applications share the same configuration.
 
-### 0.1.0
+## Changelog
 
-- First beta version release
+See [CHANGELOG.md](./CHANGELOG.md).

src/config.rs

@@ -4,27 +4,20 @@ use once_cell::sync::Lazy;
 
 use crate::consts::{COMPRESSED_PUBLIC_KEY_SIZE, UNCOMPRESSED_PUBLIC_KEY_SIZE};
 
+#[derive(Default)]
 pub enum SymmetricAlgorithm {
+    #[default]
     Aes256Gcm,
 }
 
+#[derive(Default)]
 pub struct Config {
     pub is_ephemeral_key_compressed: bool,
     pub is_hkdf_key_compressed: bool,
     pub symmetric_algorithm: SymmetricAlgorithm,
 }
 
-impl Config {
-    pub fn default() -> Self {
-        Config {
-            is_ephemeral_key_compressed: false,
-            is_hkdf_key_compressed: false,
-            symmetric_algorithm: SymmetricAlgorithm::Aes256Gcm,
-        }
-    }
-}
-
-/// Global config
+/// Global config variable
 pub static ECIES_CONFIG: Lazy<Mutex<Config>> = Lazy::new(|| {
     let config: Config = Config::default();
     Mutex::new(config)

src/consts.rs

@@ -1,10 +1,16 @@
 pub use libsecp256k1::util::{COMPRESSED_PUBLIC_KEY_SIZE, FULL_PUBLIC_KEY_SIZE as UNCOMPRESSED_PUBLIC_KEY_SIZE};
 
-/// AES IV/nonce length
-pub const AES_IV_LENGTH: usize = 16;
-/// AES tag length
-pub const AES_TAG_LENGTH: usize = 16;
-/// AES IV + tag length
-pub const AES_IV_PLUS_TAG_LENGTH: usize = AES_IV_LENGTH + AES_TAG_LENGTH;
+/// AES nonce length
+#[cfg(not(feature = "aes_12bytes_nonce"))]
+pub const AES_NONCE_LENGTH: usize = 16;
+#[cfg(feature = "aes_12bytes_nonce")]
+pub const AES_NONCE_LENGTH: usize = 12;
+
+/// AEAD tag length
+pub const AEAD_TAG_LENGTH: usize = 16;
+
+/// Nonce and tag length
+pub const NONCE_TAG_LENGTH: usize = AES_NONCE_LENGTH + AEAD_TAG_LENGTH;
+
 /// Empty bytes array
 pub const EMPTY_BYTES: [u8; 0] = [];

src/lib.rs

@@ -190,57 +190,6 @@ mod tests {
         let (sk, pk) = (&sk.serialize(), &pk.serialize_compressed());
         test_enc_dec_big(sk, pk);
     }
-
-    #[test]
-    #[cfg(not(target_arch = "wasm32"))]
-    fn test_against_python() {
-        use futures_util::FutureExt;
-        use hex::encode;
-        use tokio::runtime::Runtime;
-
-        use utils::tests::decode_hex;
-
-        const PYTHON_BACKEND: &str = "https://eciespydemo-1-d5397785.deta.app/";
-
-        let (sk, pk) = generate_keypair();
-
-        let sk_hex = encode(&sk.serialize().to_vec());
-        let uncompressed_pk = &pk.serialize();
-        let pk_hex = encode(uncompressed_pk.to_vec());
-
-        let client = reqwest::Client::new();
-        let params = [("data", MSG), ("pub", pk_hex.as_str())];
-
-        let rt = Runtime::new().unwrap();
-        let res = rt
-            .block_on(
-                client
-                    .post(PYTHON_BACKEND)
-                    .form(&params)
-                    .send()
-                    .then(|r| r.unwrap().text()),
-            )
-            .unwrap();
-
-        let server_encrypted = decode_hex(&res);
-        let local_decrypted = decrypt(&sk.serialize(), server_encrypted.as_slice()).unwrap();
-        assert_eq!(local_decrypted, MSG.as_bytes());
-
-        let local_encrypted = encrypt(uncompressed_pk, MSG.as_bytes()).unwrap();
-        let params = [("data", encode(local_encrypted)), ("prv", sk_hex)];
-
-        let res = rt
-            .block_on(
-                client
-                    .post(PYTHON_BACKEND)
-                    .form(&params)
-                    .send()
-                    .then(|r| r.unwrap().text()),
-            )
-            .unwrap();
-
-        assert_eq!(res, MSG);
-    }
 }
 
 #[cfg(all(test, target_arch = "wasm32"))]

src/openssl_aes.rs

@@ -1,19 +1,19 @@
 use openssl::symm::{decrypt_aead, encrypt_aead, Cipher};
 use rand::{thread_rng, Rng};
 
-use crate::consts::{AES_IV_LENGTH, AES_IV_PLUS_TAG_LENGTH, AES_TAG_LENGTH, EMPTY_BYTES};
+use crate::consts::{AEAD_TAG_LENGTH, AES_NONCE_LENGTH, EMPTY_BYTES, NONCE_TAG_LENGTH};
 
 /// AES-256-GCM encryption wrapper
 pub fn aes_encrypt(key: &[u8], msg: &[u8]) -> Option<Vec<u8>> {
     let cipher = Cipher::aes_256_gcm();
 
-    let mut iv = [0u8; AES_IV_LENGTH];
+    let mut iv = [0u8; AES_NONCE_LENGTH];
     thread_rng().fill(&mut iv);
 
-    let mut tag = [0u8; AES_TAG_LENGTH];
+    let mut tag = [0u8; AEAD_TAG_LENGTH];
 
     if let Ok(encrypted) = encrypt_aead(cipher, key, Some(&iv), &EMPTY_BYTES, msg, &mut tag) {
-        let mut output = Vec::with_capacity(AES_IV_PLUS_TAG_LENGTH + encrypted.len());
+        let mut output = Vec::with_capacity(NONCE_TAG_LENGTH + encrypted.len());
         output.extend(&iv);
         output.extend(&tag);
         output.extend(encrypted);
@@ -26,15 +26,15 @@ pub fn aes_encrypt(key: &[u8], msg: &[u8]) -> Option<Vec<u8>> {
 
 /// AES-256-GCM decryption wrapper
 pub fn aes_decrypt(key: &[u8], encrypted_msg: &[u8]) -> Option<Vec<u8>> {
-    if encrypted_msg.len() < AES_IV_PLUS_TAG_LENGTH {
+    if encrypted_msg.len() < NONCE_TAG_LENGTH {
         return None;
     }
 
     let cipher = Cipher::aes_256_gcm();
 
-    let iv = &encrypted_msg[..AES_IV_LENGTH];
-    let tag = &encrypted_msg[AES_IV_LENGTH..AES_IV_PLUS_TAG_LENGTH];
-    let encrypted = &encrypted_msg[AES_IV_PLUS_TAG_LENGTH..];
+    let iv = &encrypted_msg[..AES_NONCE_LENGTH];
+    let tag = &encrypted_msg[AES_NONCE_LENGTH..NONCE_TAG_LENGTH];
+    let encrypted = &encrypted_msg[NONCE_TAG_LENGTH..];
 
     decrypt_aead(cipher, key, Some(iv), &EMPTY_BYTES, encrypted, tag).ok()
 }

src/pure_aes.rs

@@ -1,19 +1,25 @@
 use aes_gcm::aead::{generic_array::GenericArray, AeadInPlace};
 use aes_gcm::{aes::Aes256, AesGcm, KeyInit};
 use rand::{thread_rng, Rng};
-use typenum::consts::U16;
+#[allow(unused_imports)]
+use typenum::consts::{U12, U16};
 
-use crate::consts::{AES_IV_LENGTH, AES_IV_PLUS_TAG_LENGTH, EMPTY_BYTES};
+use crate::consts::{AES_NONCE_LENGTH, EMPTY_BYTES, NONCE_TAG_LENGTH};
 
 /// AES-256-GCM with 16 bytes Nonce/IV
+#[cfg(not(feature = "aes_12bytes_nonce"))]
 pub type Aes256Gcm = AesGcm<Aes256, U16>;
 
+/// AES-256-GCM with 12 bytes Nonce/IV
+#[cfg(feature = "aes_12bytes_nonce")]
+pub type Aes256Gcm = AesGcm<Aes256, U12>;
+
 /// AES-256-GCM encryption wrapper
 pub fn aes_encrypt(key: &[u8], msg: &[u8]) -> Option<Vec<u8>> {
-    let key = GenericArray::from_slice(key);
+    let key: &GenericArray<u8, _> = GenericArray::from_slice(key);
     let aead = Aes256Gcm::new(key);
 
-    let mut iv = [0u8; AES_IV_LENGTH];
+    let mut iv = [0u8; AES_NONCE_LENGTH];
     thread_rng().fill(&mut iv);
 
     let nonce = GenericArray::from_slice(&iv);
@@ -22,8 +28,8 @@ pub fn aes_encrypt(key: &[u8], msg: &[u8]) -> Option<Vec<u8>> {
     out.extend(msg);
 
     if let Ok(tag) = aead.encrypt_in_place_detached(nonce, &EMPTY_BYTES, &mut out) {
-        let mut output = Vec::with_capacity(AES_IV_PLUS_TAG_LENGTH + msg.len());
-        output.extend(&iv);
+        let mut output = Vec::with_capacity(NONCE_TAG_LENGTH + msg.len());
+        output.extend(nonce);
         output.extend(tag);
         output.extend(out);
         Some(output)
@@ -34,18 +40,18 @@ pub fn aes_encrypt(key: &[u8], msg: &[u8]) -> Option<Vec<u8>> {
 
 /// AES-256-GCM decryption wrapper
 pub fn aes_decrypt(key: &[u8], encrypted_msg: &[u8]) -> Option<Vec<u8>> {
-    if encrypted_msg.len() < AES_IV_PLUS_TAG_LENGTH {
+    if encrypted_msg.len() < NONCE_TAG_LENGTH {
         return None;
     }
 
     let key = GenericArray::from_slice(key);
     let aead = Aes256Gcm::new(key);
 
-    let iv = GenericArray::from_slice(&encrypted_msg[..AES_IV_LENGTH]);
-    let tag = GenericArray::from_slice(&encrypted_msg[AES_IV_LENGTH..AES_IV_PLUS_TAG_LENGTH]);
+    let iv = GenericArray::from_slice(&encrypted_msg[..AES_NONCE_LENGTH]);
+    let tag = GenericArray::from_slice(&encrypted_msg[AES_NONCE_LENGTH..NONCE_TAG_LENGTH]);
 
-    let mut out = Vec::with_capacity(encrypted_msg.len() - AES_IV_PLUS_TAG_LENGTH);
-    out.extend(&encrypted_msg[AES_IV_PLUS_TAG_LENGTH..]);
+    let mut out = Vec::with_capacity(encrypted_msg.len() - NONCE_TAG_LENGTH);
+    out.extend(&encrypted_msg[NONCE_TAG_LENGTH..]);
 
     if let Ok(_) = aead.decrypt_in_place_detached(iv, &EMPTY_BYTES, &mut out, tag) {
         Some(out)

src/utils.rs

@@ -68,7 +68,7 @@ pub(crate) mod tests {
     use hex::decode;
 
     use super::*;
-    use crate::consts::{AES_IV_LENGTH, EMPTY_BYTES};
+    use crate::consts::EMPTY_BYTES;
 
     /// Remove 0x prefix of a hex string
     pub fn remove0x(hex: &str) -> &str {
@@ -102,8 +102,7 @@ pub(crate) mod tests {
     #[test]
     fn test_attempt_to_decrypt_invalid_message() {
         assert!(aes_decrypt(&[], &[]).is_none());
-
-        assert!(aes_decrypt(&[], &[0; AES_IV_LENGTH]).is_none());
+        assert!(aes_decrypt(&[], &[0; 16]).is_none());
     }
 
     #[test]
@@ -129,6 +128,7 @@ pub(crate) mod tests {
     }
 
     #[test]
+    #[cfg(not(feature = "aes_12bytes_nonce"))]
     fn test_aes_known_key() {
         let text = b"helloworld";
         let key = decode_hex("0000000000000000000000000000000000000000000000000000000000000000");