Add blinded pair binding

Author: SessionHero01

library/src/main/cpp/blinded_key.cpp

@@ -9,17 +9,15 @@
 // Created by Thomas Ruffie on 29/7/2024.
 //
 
+
 extern "C"
 JNIEXPORT jobject JNICALL
 Java_network_loki_messenger_libsession_1util_util_BlindKeyAPI_blindVersionKeyPair(JNIEnv *env,
                                                                                   jobject thiz,
                                                                                   jbyteArray ed25519_secret_key) {
     return jni_utils::run_catching_cxx_exception_or_throws<jobject>(env, [=] {
         const auto [pk, sk] = session::blind_version_key_pair(util::vector_from_bytes(env, ed25519_secret_key));
-
-        jclass kp_class = env->FindClass("network/loki/messenger/libsession_util/util/KeyPair");
-        jmethodID kp_constructor = env->GetMethodID(kp_class, "<init>", "([B[B)V");
-        return env->NewObject(kp_class, kp_constructor, util::bytes_from_vector(env, {pk.data(), pk.data() + pk.size()}), util::bytes_from_vector(env, {sk.data(), sk.data() + sk.size()}));
+        return jni_utils::new_key_pair(env, util::bytes_from_span(env, pk), util::bytes_from_span(env, sk));
     });
 }
 extern "C"
@@ -29,7 +27,11 @@ Java_network_loki_messenger_libsession_1util_util_BlindKeyAPI_blindVersionSign(J
                                                                                jbyteArray ed25519_secret_key,
                                                                                jlong timestamp) {
     return jni_utils::run_catching_cxx_exception_or_throws<jbyteArray>(env, [=] {
-        auto bytes = session::blind_version_sign(util::vector_from_bytes(env, ed25519_secret_key), session::Platform::android, timestamp);
+        auto bytes = session::blind_version_sign(
+                jni_utils::JavaByteArrayRef(env, ed25519_secret_key).get(),
+                session::Platform::android,
+                timestamp
+        );
         return util::bytes_from_vector(env, bytes);
     });
 }
@@ -46,16 +48,29 @@ Java_network_loki_messenger_libsession_1util_util_BlindKeyAPI_blindVersionSignRe
     return jni_utils::run_catching_cxx_exception_or_throws<jbyteArray>(env, [=] {
         auto methodC = util::string_from_jstring(env, method);
         auto pathC = util::string_from_jstring(env, path);
-        auto keyBytes = util::vector_from_bytes(env, ed25519_secret_key);
-        auto bodyBytes = body ? std::optional(util::vector_from_bytes(env, body)) : std::nullopt;
 
         auto bytes = session::blind_version_sign_request(
-                session::to_span(keyBytes),
+                jni_utils::JavaByteArrayRef(env, ed25519_secret_key).get(),
                 timestamp,
                 methodC,
                 pathC,
-                body ? std::optional(session::to_span(*bodyBytes)) : std::nullopt
+                body ? std::make_optional(jni_utils::JavaByteArrayRef(env, body).get()) : std::nullopt
         );
         return util::bytes_from_vector(env, bytes);
     });
+}
+
+extern "C"
+JNIEXPORT jobject JNICALL
+Java_network_loki_messenger_libsession_1util_util_BlindKeyAPI_blind15KeyPair(JNIEnv *env,
+                                                                             jobject thiz,
+                                                                             jbyteArray ed25519_secret_key,
+                                                                             jbyteArray server_pub_key) {
+    return jni_utils::run_catching_cxx_exception_or_throws<jobject>(env, [=] {
+        auto [pk, sk] = session::blind15_key_pair(
+                jni_utils::JavaByteArrayRef(env, ed25519_secret_key).get(),
+                jni_utils::JavaByteArrayRef(env, server_pub_key).get()
+                );
+        return jni_utils::new_key_pair(env, util::bytes_from_span(env, pk), util::bytes_from_span(env, sk));
+    });
 }

library/src/main/cpp/jni_utils.cpp

@@ -6,4 +6,10 @@ namespace jni_utils {
         jmethodID constructor = env->GetMethodID(pair_class.get(), "<init>", "(Ljava/lang/Object;Ljava/lang/Object;)V");
         return env->NewObject(pair_class.get(), constructor, first, second);
     }
+
+    jobject new_key_pair(JNIEnv *env, jbyteArray pubKey, jbyteArray secKey) {
+        auto kp_class = JavaLocalRef(env, env->FindClass("network/loki/messenger/libsession_util/util/KeyPair"));
+        jmethodID kp_constructor = env->GetMethodID(kp_class.get(), "<init>", "([B[B)V");
+        return env->NewObject(kp_class.get(), kp_constructor, pubKey, secKey);
+    }
 }

library/src/main/cpp/jni_utils.h

@@ -146,6 +146,11 @@ namespace jni_utils {
      */
     jobject new_kotlin_pair(JNIEnv *env, jobject first, jobject second);
 
+    /**
+     * Create a new KeyPair object
+     */
+    jobject new_key_pair(JNIEnv *env, jbyteArray pubKey, jbyteArray secKey);
+
     /**
      * A RAII wrapper for a Java byte array. This will automatically release the byte array when it goes out of scope.
      */

library/src/main/java/network/loki/messenger/libsession_util/util/BlindKeyAPI.kt

@@ -18,4 +18,23 @@ object BlindKeyAPI {
         method: String,
         path: String,
         body: ByteArray?): ByteArray
+
+    /**
+     * Generate a 15-blinded key pair
+     *
+     * @param ed25519SecretKey The Ed25519 secret key, 32/64 bytes
+     * @param serverPubKey The server public key, 32 bytes
+     */
+    external fun blind15KeyPair(
+        ed25519SecretKey: ByteArray,
+        serverPubKey: ByteArray,
+    ): KeyPair
+
+    /**
+     * Generate a 15-blinded key pair, returning null on failure
+     */
+    fun blind15KeyPairOrNull(
+        ed25519SecretKey: ByteArray,
+        serverPubKey: ByteArray,
+    ): KeyPair? = kotlin.runCatching { blind15KeyPair(ed25519SecretKey, serverPubKey) }.getOrNull()
 }