1 files changed, 87 insertions, 0 deletions
diff --git a/crates/secd/src/util/crypter.rs b/crates/secd/src/util/crypter.rs
new file mode 100644
index 0000000..1717377
--- /dev/null
+++ b/crates/secd/src/util/crypter.rs
@@ -0,0 +1,87 @@
+use aes_gcm::{
+    aead::{Aead, KeyInit, OsRng},
+    Aes256Gcm, Nonce,
+};
+use argon2::{
+    password_hash::{self, SaltString},
+    Argon2, PasswordHasher,
+};
+use derive_more::Display;
+use rand::Rng;
+use sha2::{Digest, Sha256};
+use thiserror::Error;
+
+#[derive(Debug, Display, Error)]
+pub enum CrypterError {
+    EncryptError(String),
+    DecryptError(String),
+    DecodeError(String),
+    HashError(String),
+}
+
+pub struct Crypter {
+    pub key: Vec<u8>,
+}
+
+impl Crypter {
+    pub fn new(key: &[u8]) -> Self {
+        Self { key: key.to_vec() }
+    }
+
+    pub fn encrypt(&self, data: &[u8]) -> Result<Vec<u8>, CrypterError> {
+        let mut hasher = Sha256::new();
+        hasher.update(&self.key);
+
+        let cipher = Aes256Gcm::new(&hasher.finalize());
+
+        let rbs = rand::thread_rng().gen::<[u8; 12]>();
+        let iv = Nonce::from_slice(&rbs);
+        let crypt = cipher
+            .encrypt(&iv, data)
+            .map_err(|e| CrypterError::EncryptError(e.to_string()))?;
+
+        let mut msg = iv.to_vec();
+        msg.extend_from_slice(&crypt);
+        Ok(msg)
+    }
+
+    pub fn decrypt(&self, data: &[u8]) -> Result<Vec<u8>, CrypterError> {
+        let mut hasher = Sha256::new();
+        hasher.update(&self.key);
+
+        let cipher = Aes256Gcm::new(&hasher.finalize());
+
+        let iv = Nonce::from_slice(&data[0..=11]);
+        let data = &data[12..];
+        Ok(cipher
+            .decrypt(&iv, data)
+            .map_err(|e| CrypterError::DecryptError(e.to_string()))?)
+    }
+
+    pub fn hash(&self, data: &[u8]) -> Result<String, CrypterError> {
+        let salt = SaltString::generate(&mut OsRng);
+        let hasher = Argon2::default();
+        Ok(hasher
+            .hash_password(data, &salt)
+            .map_err(|e| CrypterError::HashError(e.to_string()))?
+            .to_string())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn encrypt_data_test() {
+        let crypter = Crypter {
+            key: "testkey".to_string().into_bytes(),
+        };
+
+        let plaintext = "This is a secret.";
+        let enc = crypter.encrypt(&plaintext.as_bytes()).unwrap();
+
+        let res = crypter.decrypt(&enc).unwrap();
+        assert_eq!(plaintext, std::str::from_utf8(&res).unwrap());
+    }
+}