SNOW-1660409 JDBC Connector - GET file from stage weak file permissions (#2066)

Author: sfc-gh-ext-simba-jy

src/main/java/net/snowflake/client/jdbc/SnowflakeFileTransferAgent.java

@@ -5,6 +5,7 @@
 package net.snowflake.client.jdbc;
 
 import static net.snowflake.client.core.Constants.NO_SPACE_LEFT_ON_DEVICE_ERR;
+import static net.snowflake.client.jdbc.SnowflakeUtil.createOwnerOnlyPermissionDir;
 import static net.snowflake.client.jdbc.SnowflakeUtil.systemGetProperty;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
@@ -1565,8 +1566,10 @@ public boolean execute() throws SQLException {
       if (commandType == CommandType.DOWNLOAD) {
         File dir = new File(localLocation);
         if (!dir.exists()) {
-          boolean created = dir.mkdirs();
-
+          boolean created =
+              SnowflakeUtil.isWindows()
+                  ? dir.mkdirs()
+                  : createOwnerOnlyPermissionDir(localLocation);
           if (created) {
             logger.debug("Directory created: {}", localLocation);
           } else {
@@ -2507,7 +2510,7 @@ private static void pullFileFromRemoteStore(
       RemoteStoreFileEncryptionMaterial encMat,
       String presignedUrl,
       String queryId)
-      throws SQLException {
+      throws SQLException, IOException {
     remoteLocation remoteLocation = extractLocationAndPath(stage.getLocation());
 
     String stageFilePath = filePath;

src/main/java/net/snowflake/client/jdbc/SnowflakeUtil.java

@@ -13,12 +13,18 @@
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.google.common.base.Strings;
 import java.io.BufferedReader;
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.attribute.PosixFilePermission;
+import java.nio.file.attribute.PosixFilePermissions;
 import java.sql.SQLException;
 import java.sql.Time;
 import java.sql.Types;
@@ -33,6 +39,7 @@
 import java.util.Optional;
 import java.util.Properties;
 import java.util.Random;
+import java.util.Set;
 import java.util.TreeMap;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ThreadFactory;
@@ -66,6 +73,9 @@ public class SnowflakeUtil {
   private static final SFLogger logger = SFLoggerFactory.getLogger(SnowflakeUtil.class);
   private static final ObjectMapper OBJECT_MAPPER = ObjectMapperFactory.getObjectMapper();
 
+  private static final Set<PosixFilePermission> ownerOnlyPermission =
+      PosixFilePermissions.fromString("rw-------");
+
   /** Additional data types not covered by standard JDBC */
   public static final int EXTRA_TYPES_TIMESTAMP_LTZ = 50000;
 
@@ -902,6 +912,50 @@ public static Map<String, String> createCaseInsensitiveMap(Header[] headers) {
     }
   }
 
+  /** create a directory with Owner only permission (0600) */
+  @SnowflakeJdbcInternalApi
+  public static boolean createOwnerOnlyPermissionDir(String location) {
+    if (isWindows()) {
+      return false;
+    }
+
+    boolean isDirCreated = true;
+    Path dir = Paths.get(location);
+    try {
+      Files.createDirectory(dir, PosixFilePermissions.asFileAttribute(ownerOnlyPermission));
+    } catch (IOException e) {
+      logger.error(
+          "Failed to set OwnerOnly permission for {}. This may cause the file download to fail ",
+          location);
+      isDirCreated = false;
+    }
+    return isDirCreated;
+  }
+
+  @SnowflakeJdbcInternalApi
+  public static void assureOnlyUserAccessibleFilePermissions(File file) throws IOException {
+    if (isWindows()) {
+      return;
+    }
+    boolean disableUserPermissions =
+        file.setReadable(false, false)
+            && file.setWritable(false, false)
+            && file.setExecutable(false, false);
+    boolean setOwnerPermissionsOnly = file.setReadable(true, true) && file.setWritable(true, true);
+
+    if (disableUserPermissions && setOwnerPermissionsOnly) {
+      logger.info("Successfuly set OwnerOnly permission for {}. ", file.getAbsolutePath());
+    } else {
+      file.delete();
+      logger.error(
+          "Failed to set OwnerOnly permission for {}. Failed to download", file.getAbsolutePath());
+      throw new IOException(
+          String.format(
+              "Failed to set OwnerOnly permission for %s. Failed to download",
+              file.getAbsolutePath()));
+    }
+  }
+
   /**
    * Check whether the OS is Windows
    *

src/main/java/net/snowflake/client/jdbc/cloud/storage/SnowflakeAzureClient.java

@@ -343,6 +343,7 @@ public void download(
         transferOptions.setConcurrentRequestCount(parallelism);
 
         blob.downloadToFile(localFilePath, null, transferOptions, opContext);
+        SnowflakeUtil.assureOnlyUserAccessibleFilePermissions(localFile);
         stopwatch.stop();
         long downloadMillis = stopwatch.elapsedMillis();
 

src/main/java/net/snowflake/client/jdbc/cloud/storage/SnowflakeGCSClient.java

@@ -314,6 +314,7 @@ public void download(
               outStream.flush();
               outStream.close();
               bodyStream.close();
+              SnowflakeUtil.assureOnlyUserAccessibleFilePermissions(localFile);
               if (isEncrypting()) {
                 Map<String, String> userDefinedHeaders =
                     createCaseInsensitiveMap(response.getAllHeaders());
@@ -351,6 +352,7 @@ public void download(
           logger.debug("Starting download without presigned URL", false);
           blob.downloadTo(
               localFile.toPath(), Blob.BlobSourceOption.shouldReturnRawInputStream(true));
+          SnowflakeUtil.assureOnlyUserAccessibleFilePermissions(localFile);
           stopwatch.stop();
           downloadMillis = stopwatch.elapsedMillis();
           logger.debug("Download successful", false);

src/main/java/net/snowflake/client/jdbc/cloud/storage/SnowflakeS3Client.java

@@ -387,7 +387,7 @@ public ExecutorService newExecutor() {
         String iv = metaMap.get(AMZ_IV);
 
         myDownload.waitForCompletion();
-
+        SnowflakeUtil.assureOnlyUserAccessibleFilePermissions(localFile);
         stopwatch.stop();
         long downloadMillis = stopwatch.elapsedMillis();
 

src/test/java/net/snowflake/client/jdbc/SnowflakeUtilTest.java

@@ -4,6 +4,7 @@
 package net.snowflake.client.jdbc;
 
 import static net.snowflake.client.jdbc.SnowflakeUtil.createCaseInsensitiveMap;
+import static net.snowflake.client.jdbc.SnowflakeUtil.createOwnerOnlyPermissionDir;
 import static net.snowflake.client.jdbc.SnowflakeUtil.extractColumnMetadata;
 import static net.snowflake.client.jdbc.SnowflakeUtil.getSnowflakeType;
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -15,18 +16,28 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.PosixFileAttributes;
+import java.nio.file.attribute.PosixFilePermission;
+import java.nio.file.attribute.PosixFilePermissions;
 import java.sql.Types;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
 import java.util.TreeMap;
+import net.snowflake.client.annotations.DontRunOnWindows;
 import net.snowflake.client.category.TestTags;
 import net.snowflake.client.core.ObjectMapperFactory;
 import org.apache.http.Header;
 import org.apache.http.message.BasicHeader;
 import org.junit.jupiter.api.Tag;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 
 @Tag(TestTags.CORE)
 public class SnowflakeUtilTest extends BaseJDBCTest {
@@ -117,6 +128,33 @@ public void shouldConvertHeadersCreateCaseInsensitiveMap() {
     assertEquals("value2", map.get("Key2"));
   }
 
+  @Test
+  @DontRunOnWindows
+  public void testCreateOwnerOnlyPermissionDir(@TempDir Path tempDir)
+      throws IOException, UnsupportedOperationException {
+    Path tmp = tempDir.resolve("folder-permission-testing");
+    String folderPath = tmp.toString();
+    boolean isDirCreated = createOwnerOnlyPermissionDir(folderPath);
+    assertTrue(isDirCreated);
+    assertTrue(tmp.toFile().isDirectory());
+    PosixFileAttributes attributes = Files.readAttributes(tmp, PosixFileAttributes.class);
+    Set<PosixFilePermission> permissions = attributes.permissions();
+    assertEquals(PosixFilePermissions.toString(permissions), "rw-------");
+  }
+
+  @Test
+  @DontRunOnWindows
+  public void testValidateFilePermission(@TempDir Path tempDir)
+      throws IOException, UnsupportedOperationException {
+    Path tmp = tempDir.resolve("fileTesting.txt");
+    File file = tmp.toFile();
+    assertTrue(file.createNewFile());
+    SnowflakeUtil.assureOnlyUserAccessibleFilePermissions(file);
+    PosixFileAttributes attributes = Files.readAttributes(tmp, PosixFileAttributes.class);
+    Set<PosixFilePermission> permissions = attributes.permissions();
+    assertEquals(PosixFilePermissions.toString(permissions), "rw-------");
+  }
+
   private static SnowflakeColumnMetadata createExpectedMetadata(
       JsonNode rootNode, JsonNode fieldOne, JsonNode fieldTwo) throws SnowflakeSQLLoggedException {
     ColumnTypeInfo columnTypeInfo =