import java.io.IOException;
import java.io.PrintWriter;
+import java.util.HashMap;
import java.util.Map;
-import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.cacert.gigi.GigiApiException;
import org.cacert.gigi.localisation.Language;
+import org.cacert.gigi.pages.LoginPage;
import org.cacert.gigi.pages.Page;
import org.cacert.gigi.util.RandomToken;
+/**
+ * A generic HTML-form that handles CSRF-token creation.
+ */
public abstract class Form implements Outputable {
+ public static class PermamentFormException extends RuntimeException {
+
+ public PermamentFormException(GigiApiException cause) {
+ super(cause);
+ }
+
+ @Override
+ public synchronized GigiApiException getCause() {
+ return (GigiApiException) super.getCause();
+ }
+ }
+
public static final String CSRF_FIELD = "csrf";
- private String csrf;
+ private static final String SUBMIT_EXCEPTION = "form-submit-exception";
+
+ private final String csrf;
+
+ private final String action;
+ /**
+ * Creates a new {@link Form}.
+ *
+ * @param hsr
+ * the request to register the form against.
+ */
public Form(HttpServletRequest hsr) {
+ this(hsr, null);
+ }
+
+ /**
+ * Creates a new {@link Form}.
+ *
+ * @param hsr
+ * the request to register the form against.
+ * @param action
+ * the target path where the form should be submitted.
+ */
+ public Form(HttpServletRequest hsr, String action) {
csrf = RandomToken.generateToken(32);
+ this.action = action;
HttpSession hs = hsr.getSession();
hs.setAttribute("form/" + getClass().getName() + "/" + csrf, this);
+ }
+ /**
+ * Update the forms internal state based on submitted data.
+ *
+ * @param req
+ * the request to take the initial data from.
+ * @return true, iff the form succeeded and the user should be redirected.
+ * @throws GigiApiException
+ * if form data had problems or operations went wrong.
+ */
+ public abstract boolean submit(HttpServletRequest req) throws GigiApiException;
+
+ /**
+ * Calls {@link #submit(PrintWriter, HttpServletRequest)} while catching and
+ * displaying errors ({@link GigiApiException}), and re-outputing the form
+ * via {@link #output(PrintWriter, Language, Map)}.
+ *
+ * @param out
+ * the target to write the form and errors to
+ * @param req
+ * the request that this submit originated (for submit and for
+ * language)
+ * @return as {@link #submit(PrintWriter, HttpServletRequest)}: true, iff
+ * the form succeeded and the user should be redirected.
+ */
+ public boolean submitProtected(PrintWriter out, HttpServletRequest req) {
+ try {
+ boolean succeeded = submit(req);
+ if (succeeded) {
+ HttpSession hs = req.getSession();
+ hs.removeAttribute("form/" + getClass().getName() + "/" + csrf);
+ return true;
+ }
+ } catch (GigiApiException e) {
+ e.format(out, LoginPage.getLanguage(req));
+ }
+ output(out, LoginPage.getLanguage(req), new HashMap<String, Object>());
+ return false;
}
- public abstract boolean submit(PrintWriter out, HttpServletRequest req) throws GigiApiException;
+ public boolean submitExceptionProtected(HttpServletRequest req) {
+ try {
+ if (submit(req)) {
+ HttpSession hs = req.getSession();
+ hs.removeAttribute("form/" + getClass().getName() + "/" + csrf);
+ return true;
+ }
+ return false;
+ } catch (PermamentFormException e) {
+ req.setAttribute(SUBMIT_EXCEPTION, e);
+ return false;
+ } catch (GigiApiException e) {
+ req.setAttribute(SUBMIT_EXCEPTION, e);
+ return false;
+ }
+ }
+
+ /**
+ * Prints any errors in any form submits on this request.
+ *
+ * @param req
+ * The request to extract the errors from.
+ * @param out
+ * the output stream to the user to write the errors to.
+ * @return true if no permanent errors occurred and the form should be
+ * reprinted.
+ */
+ public static boolean printFormErrors(HttpServletRequest req, PrintWriter out) {
+ Object o = req.getAttribute(SUBMIT_EXCEPTION);
+ if (o != null && (o instanceof PermamentFormException)) {
+ ((PermamentFormException) o).getCause().format(out, Page.getLanguage(req));
+ return false;
+ }
+ if (o != null && (o instanceof GigiApiException)) {
+ ((GigiApiException) o).format(out, Page.getLanguage(req));
+ }
+ return true;
+ }
protected String getCsrfFieldName() {
return CSRF_FIELD;
@Override
public void output(PrintWriter out, Language l, Map<String, Object> vars) {
- out.println("<form method='POST'>");
- failed = false;
+ if (action == null) {
+ out.println("<form method='POST'>");
+ } else {
+ out.println("<form method='POST' action='" + action + "'>");
+ }
outputContent(out, l, vars);
out.print("<input type='hidden' name='" + CSRF_FIELD + "' value='");
out.print(getCSRFToken());
out.println("'></form>");
}
+ /**
+ * Outputs the forms contents.
+ *
+ * @param out
+ * Stream to the user.
+ * @param l
+ * {@link Language} to translate text to.
+ * @param vars
+ * Variables supplied from the outside.
+ */
protected abstract void outputContent(PrintWriter out, Language l, Map<String, Object> vars);
- boolean failed;
-
- protected void outputError(PrintWriter out, ServletRequest req, String text, Object... contents) {
- if ( !failed) {
- failed = true;
- out.println("<div class='formError'>");
- }
- out.print("<div>");
- if (contents.length == 0) {
- out.print(Page.translate(req, text));
- } else {
- out.print(String.format(Page.translate(req, text), contents));
- }
- out.println("</div>");
- }
-
- protected void outputErrorPlain(PrintWriter out, String text) {
- if ( !failed) {
- failed = true;
- out.println("<div class='formError'>");
- }
- out.print("<div>");
- out.print(text);
- out.println("</div>");
- }
-
- public boolean isFailed(PrintWriter out) {
- if (failed) {
- out.println("</div>");
- }
- return failed;
- }
-
protected String getCSRFToken() {
return csrf;
}
+ /**
+ * Re-fetches a form e.g. when a Post-request is received.
+ *
+ * @param req
+ * the request that is directed to the form.
+ * @param target
+ * the {@link Class} of the expected form.
+ * @return the form where this request is directed to.
+ * @throws CSRFException
+ * if no CSRF-token is found or the token is wrong.
+ */
+ @SuppressWarnings("unchecked")
public static <T extends Form> T getForm(HttpServletRequest req, Class<T> target) throws CSRFException {
String csrf = req.getParameter(CSRF_FIELD);
if (csrf == null) {
if (hs == null) {
throw new CSRFException();
}
- Form f = (Form) hs.getAttribute("form/" + target.getName() + "/" + csrf);
+ Object f = hs.getAttribute("form/" + target.getName() + "/" + csrf);
if (f == null) {
throw new CSRFException();
}
+ if ( !(f instanceof Form)) {
+ throw new CSRFException();
+ }
+ if ( !target.isInstance(f)) {
+ throw new CSRFException();
+ }
+ // Dynamic Cast checked by previous if statement
return (T) f;
}
public static class CSRFException extends IOException {
+ private static final long serialVersionUID = 59708247477988362L;
+
}
}
projects / gigi.git / blobdiff