feat(rust): add crypto module (HKDF + AES-256-GCM + RSA verify)

native/craft-core/Cargo.toml

@@ -24,6 +24,9 @@ chrono = { version = "0.4", features = ["serde"] }
 [target.'cfg(target_os = "windows")'.dependencies]
 windows-sys = { version = "0.52", features = ["Win32_System_Diagnostics_Debug"], optional = true }
 
+[dev-dependencies]
+rand = "0.8"
+
 [build-dependencies]
 sha2 = "0.10"
 

native/craft-core/src/crypto.rs

@@ -0,0 +1,144 @@
+use aes_gcm::aead::{Aead, KeyInit, OsRng};
+use aes_gcm::{Aes256Gcm, Nonce};
+use base64::engine::general_purpose::URL_SAFE_NO_PAD;
+use base64::Engine;
+use hkdf::Hkdf;
+use rsa::signature::Verifier;
+use rsa::{Pkcs1v15Sign, RsaPublicKey};
+use sha2::{Digest, Sha256};
+
+use crate::error::LicenseError;
+
+const EMBEDDED_AES_SALT: &[u8] = b"craftlabs-license-salt-v1-2026-05";
+const AES_NONCE_SIZE: usize = 12;
+
+pub fn verify_rsa_signature(
+    public_key_pem: &str,
+    data: &[u8],
+    signature_b64: &str,
+) -> Result<(), LicenseError> {
+    use rsa::pkcs8::DecodePublicKey;
+
+    let pub_key = RsaPublicKey::from_public_key_pem(public_key_pem)
+        .map_err(|_| LicenseError::InvalidSignature)?;
+
+    let sig_bytes = URL_SAFE_NO_PAD
+        .decode(signature_b64)
+        .map_err(|_| LicenseError::InvalidFormat("signature base64"))?;
+
+    let mut hasher = Sha256::new();
+    hasher.update(data);
+    let digest = hasher.finalize();
+
+    pub_key
+        .verify(Pkcs1v15Sign::new::<Sha256>(), &digest, sig_bytes.as_slice())
+        .map_err(|_| LicenseError::SignatureMismatch)
+}
+
+pub fn derive_aes_key(license_id: &str) -> [u8; 32] {
+    let hk = Hkdf::<Sha256>::new(None, EMBEDDED_AES_SALT);
+    let mut okm = [0u8; 32];
+    hk.expand(license_id.as_bytes(), &mut okm)
+        .expect("HKDF expand for 32 bytes");
+    okm
+}
+
+pub fn aes_gcm_decrypt(key: &[u8; 32], encrypted_data: &[u8]) -> Result<Vec<u8>, LicenseError> {
+    if encrypted_data.len() < AES_NONCE_SIZE + 16 {
+        return Err(LicenseError::DecryptionFailed);
+    }
+
+    let (nonce_bytes, ciphertext) = encrypted_data.split_at(AES_NONCE_SIZE);
+    let nonce = Nonce::from_slice(nonce_bytes);
+    let cipher =
+        Aes256Gcm::new_from_slice(key).map_err(|_| LicenseError::CryptoError)?;
+    cipher
+        .decrypt(nonce, ciphertext)
+        .map_err(|_| LicenseError::DecryptionFailed)
+}
+
+pub fn aes_gcm_encrypt(key: &[u8; 32], plaintext: &[u8]) -> Vec<u8> {
+    use aes_gcm::aead::rand_core::RngCore;
+    let mut nonce_bytes = [0u8; AES_NONCE_SIZE];
+    OsRng.fill_bytes(&mut nonce_bytes);
+    let nonce = Nonce::from_slice(&nonce_bytes);
+    let cipher = Aes256Gcm::new_from_slice(key).expect("AES key valid");
+    let mut result = nonce_bytes.to_vec();
+    result.extend(cipher.encrypt(nonce, plaintext).expect("encrypt ok"));
+    result
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_derive_aes_key_deterministic() {
+        let k1 = derive_aes_key("01JQABCDEFFGHIJKLMNOPQRSTUV");
+        let k2 = derive_aes_key("01JQABCDEFFGHIJKLMNOPQRSTUV");
+        assert_eq!(k1, k2);
+    }
+
+    #[test]
+    fn test_derive_aes_key_different_ids() {
+        let k1 = derive_aes_key("id-001");
+        let k2 = derive_aes_key("id-002");
+        assert_ne!(k1, k2);
+    }
+
+    #[test]
+    fn test_aes_encrypt_decrypt_roundtrip() {
+        let key = derive_aes_key("roundtrip-test");
+        let plaintext = b"hello selfhosted licensing!";
+        let encrypted = aes_gcm_encrypt(&key, plaintext);
+        let decrypted = aes_gcm_decrypt(&key, &encrypted).unwrap();
+        assert_eq!(decrypted, plaintext);
+    }
+
+    #[test]
+    fn test_aes_decrypt_wrong_key_fails() {
+        let key1 = derive_aes_key("id-1");
+        let key2 = derive_aes_key("id-2");
+        let plaintext = b"secret data";
+        let encrypted = aes_gcm_encrypt(&key1, plaintext);
+        let result = aes_gcm_decrypt(&key2, &encrypted);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_aes_decrypt_tampered_data_fails() {
+        let key = derive_aes_key("tamper-test");
+        let plaintext = b"original";
+        let mut encrypted = aes_gcm_encrypt(&key, plaintext);
+        if encrypted.len() > 20 {
+            encrypted[20] ^= 0xFF;
+        }
+        let result = aes_gcm_decrypt(&key, &encrypted);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_rsa_verify_with_generated_keypair() {
+        use rsa::pkcs8::EncodePublicKey;
+        use rsa::signature::Signer;
+        use rsa::RsaPrivateKey;
+        use rand::rngs::OsRng;
+
+        let mut rng = OsRng;
+        let priv_key = RsaPrivateKey::new(&mut rng, 2048).unwrap();
+        let pub_key = RsaPublicKey::from(&priv_key);
+        let pub_pem = pub_key.to_public_key_pem().unwrap();
+
+        let data = b"test data to sign";
+        let mut hasher = Sha256::new();
+        hasher.update(data);
+        let digest = hasher.finalize();
+        let sig = priv_key
+            .sign(Pkcs1v15Sign::new::<Sha256>(), &digest)
+            .unwrap();
+        let sig_b64 = URL_SAFE_NO_PAD.encode(sig.as_bytes());
+
+        assert!(verify_rsa_signature(&pub_pem, data, &sig_b64).is_ok());
+        assert!(verify_rsa_signature(&pub_pem, b"tampered", &sig_b64).is_err());
+    }
+}

native/craft-core/src/lib.rs

@@ -12,6 +12,7 @@ mod license;
 mod security;
 mod error;
 mod session;
+pub mod crypto;
 
 pub struct CraftContext {
     dummy: i32,