Merge pull request #98 from kennethshackleton/jni-raw-key

Move key stringing off the Java heap and into jni.

Lib/src/main/kotlin/com/bloomberg/selekt/Key.kt

@@ -16,8 +16,10 @@
 
 package com.bloomberg.selekt
 
+import com.bloomberg.selekt.annotations.Generated
+import com.bloomberg.selekt.commons.zero
+
 private const val KEY_SIZE = 32
-private fun ByteArray.asBlobLiteral() = "x'${joinToString("") { "%02X".format(it) }}'"
 
 internal class Key(value: ByteArray) {
     init {
@@ -31,7 +33,14 @@ internal class Key(value: ByteArray) {
         value.fill(0)
     }
 
-    operator fun invoke() = synchronized(lock) {
-        value.asBlobLiteral()
+    @Generated
+    inline fun <R> use(action: (ByteArray) -> R) = synchronized(lock) {
+        value.copyOf()
+    }.let {
+        try {
+            action(it)
+        } finally {
+            it.zero()
+        }
     }
 }

Lib/src/main/kotlin/com/bloomberg/selekt/SQLConnection.kt

@@ -49,7 +49,7 @@ internal class SQLConnection constructor(
 
     init {
         runCatching {
-            key?.let { sqlite.exec(pointer, "PRAGMA key=\"${it()}\"") }
+            key?.use { sqlite.rawKey(pointer, it) }
             sqlite.extendedResultCodes(pointer, 0)
             configuration.trace?.let { sqlite.traceV2(pointer, it()) }
             sqlite.busyTimeout(pointer, configuration.busyTimeoutMillis)

Lib/src/main/kotlin/com/bloomberg/selekt/SQLite.kt

@@ -197,6 +197,8 @@ open class SQLite(
         statementHolder: LongArray
     ) = checkConnectionSQLCode(db, sqlite.prepareV2(db, sql, sql.length, statementHolder))
 
+    fun rawKey(db: Long, key: ByteArray) = checkConnectionSQLCode(db, sqlite.rawKey(db, key, key.size))
+
     fun rekey(db: Long, key: ByteArray) = checkConnectionSQLCode(db, sqlite.rekey(db, key, key.size))
 
     fun releaseMemory(bytes: Int) = sqlite.releaseMemory(bytes)

Lib/src/main/kotlin/com/bloomberg/selekt/commons/ByteArrays.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2021 Bloomberg Finance L.P.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.bloomberg.selekt.commons
+
+internal fun ByteArray.zero() = fill(0)

Lib/src/test/kotlin/com/bloomberg/selekt/commons/ByteArraysKtTest.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2021 Bloomberg Finance L.P.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.bloomberg.selekt.commons
+
+import org.junit.jupiter.api.Test
+import kotlin.test.assertEquals
+
+internal class ByteArraysKtTest {
+    @Test
+    fun zero() {
+        byteArrayOf(0x42).let {
+            it.zero()
+            assertEquals(0, it.first())
+        }
+    }
+}

SQLite3/sqlite3_jni.cpp

@@ -630,6 +630,32 @@ Java_com_bloomberg_selekt_ExternalSQLite_prepareV2(
     return result;
 }
 
+extern "C" JNIEXPORT jint JNICALL
+Java_com_bloomberg_selekt_ExternalSQLite_rawKey(
+    JNIEnv* env,
+    jobject jobj,
+    jlong jdb,
+    jbyteArray jkey,
+    jint keyLength
+) {
+    AutoJByteArray key(env, jkey, keyLength);
+    std::string prefix = "PRAGMA key=\"x'";
+    std::string suffix = "'\"";
+    size_t const length = prefix.length() + (2 * keyLength) + suffix.length();
+    char sql[length + 1];
+    sql[length] = 0;
+    std::strcpy(sql, prefix.c_str());
+    int i;
+    char * const hex = sql + prefix.length();
+    for (i = 0; i < keyLength; ++i) {
+        std::sprintf(hex + (2 * i), "%02x", key[i]);
+    }
+    std::strcpy(sql + length - suffix.length(), suffix.c_str());
+    auto result = sqlite3_exec(reinterpret_cast<sqlite3*>(jdb), sql, nullptr, nullptr, nullptr);
+    std::fill(sql, sql + length + 1, 0);
+    return result;
+}
+
 extern "C" JNIEXPORT jint JNICALL
 Java_com_bloomberg_selekt_ExternalSQLite_rekey(
     JNIEnv* env,

SQLite3/src/main/kotlin/com/bloomberg/selekt/ExternalSQLite3.kt

@@ -171,6 +171,8 @@ class ExternalSQLite private constructor(
 
     external fun prepareV2(db: Long, sql: String, length: Int, statementHolder: LongArray): SQLCode
 
+    external fun rawKey(db: Long, key: ByteArray, length: Int): SQLCode
+
     external fun rekey(db: Long, key: ByteArray, length: Int): SQLCode
 
     external fun releaseMemory(bytes: Int): Int