org.obiba.opal.fs.security.SecuredFileObject.java Source code

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Here is the source code for org.obiba.opal.fs.security.SecuredFileObject.java

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/*******************************************************************************
 * Copyright (c) 2011 OBiBa. All rights reserved.
 *
 * This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package org.obiba.opal.fs.security;

import java.util.Arrays;
import java.util.List;

import javax.annotation.Nullable;

import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSelector;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.NameScope;
import org.apache.commons.vfs2.impl.DecoratedFileObject;
import org.obiba.magma.security.Authorizer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;

class SecuredFileObject extends DecoratedFileObject {

    private static final Logger log = LoggerFactory.getLogger(SecuredFileObject.class);

    private final Authorizer authorizer;

    SecuredFileObject(Authorizer authorizer, FileObject decoratedFileObject) {
        super(decoratedFileObject);
        this.authorizer = authorizer;
    }

    @Override
    public void findFiles(FileSelector selector, boolean depthwise, List<FileObject> selected)
            throws FileSystemException {
        super.findFiles(selector, depthwise, selected);

        List<FileObject> securedSelected = Lists.newArrayList();
        for (FileObject file : selected) {
            securedSelected.add(new SecuredFileObject(authorizer, file));
        }
        selected.clear();
        selected.addAll(securedSelected);
    }

    @Override
    public FileObject[] findFiles(FileSelector selector) throws FileSystemException {
        return toSecuredFileObjects(super.findFiles(selector));
    }

    @Nullable
    @Override
    public FileObject getChild(String name) throws FileSystemException {
        FileObject child = super.getChild(name);
        if (child == null)
            return null;
        return new SecuredFileObject(authorizer, child);
    }

    @Override
    public FileObject[] getChildren() throws FileSystemException {
        return toSecuredFileObjects(super.getChildren());
    }

    @Override
    public FileObject getParent() throws FileSystemException {
        FileObject parent = super.getParent();
        return parent == null ? null : new SecuredFileObject(authorizer, parent);
    }

    @Override
    public boolean isReadable() throws FileSystemException {
        return super.isReadable() && isPermitted(getDecoratedFileObject(), "GET");
    }

    @Override
    public boolean isWriteable() throws FileSystemException {
        return super.isWriteable() && isPermitted(getDecoratedFileObject(), "POST");
    }

    @Override
    public FileObject resolveFile(String name, NameScope scope) throws FileSystemException {
        return new SecuredFileObject(authorizer, super.resolveFile(name, scope));
    }

    @Override
    public FileObject resolveFile(String path) throws FileSystemException {
        return new SecuredFileObject(authorizer, super.resolveFile(path));
    }

    @Override
    public boolean delete() throws FileSystemException {
        if (isPermitted(getDecoratedFileObject(), "DELETE")) {
            return super.delete();
        }
        throw new FileSystemException("vfs.provider.local/delete-file.error", getName());
    }

    @Override
    public void moveTo(FileObject destFile) throws FileSystemException {
        FileObject sourceFile = getDecoratedFileObject();

        if (isPermitted(sourceFile, "DELETE")) {
            if (!(destFile instanceof SecuredFileObject)) {
                super.moveTo(destFile);
                return;
            }

            sourceFile.moveTo(((DecoratedFileObject) destFile).getDecoratedFileObject());
            return;
        }
        throw new FileSystemException("vfs.provider.local/delete-file.error", getName());
    }

    @Nullable
    private FileObject[] toSecuredFileObjects(FileObject... children) {
        if (children == null)
            return null;

        FileObject[] secured = new FileObject[children.length];
        for (int i = 0; i < children.length; i++) {
            secured[i] = new SecuredFileObject(authorizer, children[i]);
        }

        return secured;
    }

    private boolean isPermitted(FileObject file, String method) {
        String permission = "rest:/files" + file.getName().getPath() + ":" + method;
        log.trace("checking permission {}", permission);
        return authorizer.isPermitted(permission);
    }
}