// Copyright (C) 2010 The Android Open Source Project
//
// 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.google.gerrit.server.project;
import static com.google.common.base.Preconditions.checkArgument;
import com.google.gerrit.common.data.Permission;
import com.google.gerrit.common.data.PermissionRange;
import com.google.gerrit.common.data.PermissionRule;
import com.google.gerrit.extensions.client.ProjectState;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.reviewdb.client.Change;
import com.google.gerrit.reviewdb.client.Project;
import com.google.gerrit.reviewdb.client.RefNames;
import com.google.gerrit.reviewdb.server.ReviewDb;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.group.SystemGroupBackend;
import com.google.gerrit.server.notedb.ChangeNotes;
import com.google.gerrit.server.permissions.FailedPermissionBackend;
import com.google.gerrit.server.permissions.PermissionBackend.ForChange;
import com.google.gerrit.server.permissions.PermissionBackend.ForRef;
import com.google.gerrit.server.permissions.PermissionBackendException;
import com.google.gerrit.server.permissions.RefPermission;
import com.google.gerrit.server.query.change.ChangeData;
import com.google.gwtorm.server.OrmException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevObject;
import org.eclipse.jgit.revwalk.RevTag;
import org.eclipse.jgit.revwalk.RevWalk;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** Manages access control for Git references (aka branches, tags). */
public class RefControl {
private static final Logger log = LoggerFactory.getLogger(RefControl.class);
private final ProjectControl projectControl;
private final String refName;
/** All permissions that apply to this reference. */
private final PermissionCollection relevant;
/** Cached set of permissions matching this user. */
private final Map<String, List<PermissionRule>> effective;
private Boolean owner;
private Boolean canForgeAuthor;
private Boolean canForgeCommitter;
private Boolean isVisible;
RefControl(ProjectControl projectControl, String ref, PermissionCollection relevant) {
this.projectControl = projectControl;
this.refName = ref;
this.relevant = relevant;
this.effective = new HashMap<>();
}
public String getRefName() {
return refName;
}
public ProjectControl getProjectControl() {
return projectControl;
}
public CurrentUser getUser() {
return projectControl.getUser();
}
public RefControl forUser(CurrentUser who) {
ProjectControl newCtl = projectControl.forUser(who);
if (relevant.isUserSpecific()) {
return newCtl.controlForRef(getRefName());
}
return new RefControl(newCtl, getRefName(), relevant);
}
/** Is this user a ref owner? */
public boolean isOwner() {
if (owner == null) {
if (canPerform(Permission.OWNER)) {
owner = true;
} else {
owner = projectControl.isOwner();
}
}
return owner;
}
/** Can this user see this reference exists? */
public boolean isVisible() {
if (isVisible == null) {
isVisible =
(getUser().isInternalUser() || canPerform(Permission.READ))
&& isProjectStatePermittingRead();
}
return isVisible;
}
/** Can this user see other users change edits? */
public boolean isEditVisible() {
return canViewPrivateChanges();
}
/** True if this reference is visible by all REGISTERED_USERS */
public boolean isVisibleByRegisteredUsers() {
List<PermissionRule> access = relevant.getPermission(Permission.READ);
List<PermissionRule> overridden = relevant.getOverridden(Permission.READ);
Set<ProjectRef> allows = new HashSet<>();
Set<ProjectRef> blocks = new HashSet<>();
for (PermissionRule rule : access) {
if (rule.isBlock()) {
blocks.add(relevant.getRuleProps(rule));
} else if (SystemGroupBackend.isAnonymousOrRegistered(rule.getGroup())) {
allows.add(relevant.getRuleProps(rule));
}
}
for (PermissionRule rule : overridden) {
if (SystemGroupBackend.isAnonymousOrRegistered(rule.getGroup())) {
blocks.remove(relevant.getRuleProps(rule));
}
}
blocks.removeAll(allows);
return blocks.isEmpty() && !allows.isEmpty();
}
/**
* Determines whether the user can upload a change to the ref controlled by this object.
*
* @return {@code true} if the user specified can upload a change to the Git ref
*/
public boolean canUpload() {
return projectControl.controlForRef("refs/for/" + getRefName()).canPerform(Permission.PUSH)
&& isProjectStatePermittingWrite();
}
/** @return true if this user can add a new patch set to this ref */
boolean canAddPatchSet() {
return projectControl
.controlForRef("refs/for/" + getRefName())
.canPerform(Permission.ADD_PATCH_SET)
&& isProjectStatePermittingWrite();
}
/** @return true if this user can submit merge patch sets to this ref */
public boolean canUploadMerges() {
return projectControl
.controlForRef("refs/for/" + getRefName())
.canPerform(Permission.PUSH_MERGE)
&& isProjectStatePermittingWrite();
}
/** @return true if this user can rebase changes on this ref */
boolean canRebase() {
return canPerform(Permission.REBASE) && isProjectStatePermittingWrite();
}
/** @return true if this user can submit patch sets to this ref */
public boolean canSubmit(boolean isChangeOwner) {
if (RefNames.REFS_CONFIG.equals(refName)) {
// Always allow project owners to submit configuration changes.
// Submitting configuration changes modifies the access control
// rules. Allowing this to be done by a non-project-owner opens
// a security hole enabling editing of access rules, and thus
// granting of powers beyond submitting to the configuration.
return projectControl.isOwner();
}
return canPerform(Permission.SUBMIT, isChangeOwner) && isProjectStatePermittingWrite();
}
/** @return true if the user can update the reference as a fast-forward. */
private boolean canUpdate() {
if (RefNames.REFS_CONFIG.equals(refName) && !projectControl.isOwner()) {
// Pushing requires being at least project owner, in addition to push.
// Pushing configuration changes modifies the access control
// rules. Allowing this to be done by a non-project-owner opens
// a security hole enabling editing of access rules, and thus
// granting of powers beyond pushing to the configuration.
// On the AllProjects project the owner access right cannot be assigned,
// this why for the AllProjects project we allow administrators to push
// configuration changes if they have push without being project owner.
if (!(projectControl.getProjectState().isAllProjects()
&& getUser().getCapabilities().isAdmin_DoNotUse())) {
return false;
}
}
return canPerform(Permission.PUSH) && isProjectStatePermittingWrite();
}
/** @return true if the user can rewind (force push) the reference. */
private boolean canForceUpdate() {
if (!isProjectStatePermittingWrite()) {
return false;
}
if (canPushWithForce()) {
return true;
}
switch (getUser().getAccessPath()) {
case GIT:
return false;
case JSON_RPC:
case REST_API:
case SSH_COMMAND:
case UNKNOWN:
case WEB_BROWSER:
default:
return getUser().getCapabilities().isAdmin_DoNotUse()
|| (isOwner() && !isForceBlocked(Permission.PUSH));
}
}
private boolean isProjectStatePermittingWrite() {
return getProjectControl().getProject().getState().equals(ProjectState.ACTIVE);
}
private boolean isProjectStatePermittingRead() {
return getProjectControl().getProject().getState().equals(ProjectState.READ_ONLY)
|| isProjectStatePermittingWrite();
}
private boolean canPushWithForce() {
if (!isProjectStatePermittingWrite()
|| (RefNames.REFS_CONFIG.equals(refName) && !projectControl.isOwner())) {
// Pushing requires being at least project owner, in addition to push.
// Pushing configuration changes modifies the access control
// rules. Allowing this to be done by a non-project-owner opens
// a security hole enabling editing of access rules, and thus
// granting of powers beyond pushing to the configuration.
return false;
}
return canForcePerform(Permission.PUSH);
}
/**
* Determines whether the user can create a new Git ref.
*
* @param db db for checking change visibility.
* @param repo repository on which user want to create
* @param object the object the user will start the reference with.
* @return {@code true} if the user specified can create a new Git ref
*/
public boolean canCreate(ReviewDb db, Repository repo, RevObject object) {
if (!isProjectStatePermittingWrite()) {
return false;
}
if (object instanceof RevCommit) {
if (!canPerform(Permission.CREATE)) {
// No create permissions.
return false;
}
return canCreateCommit(db, repo, (RevCommit) object);
} else if (object instanceof RevTag) {
final RevTag tag = (RevTag) object;
try (RevWalk rw = new RevWalk(repo)) {
rw.parseBody(tag);
} catch (IOException e) {
return false;
}
// If tagger is present, require it matches the user's email.
//
final PersonIdent tagger = tag.getTaggerIdent();
if (tagger != null) {
boolean valid;
if (getUser().isIdentifiedUser()) {
final String addr = tagger.getEmailAddress();
valid = getUser().asIdentifiedUser().hasEmailAddress(addr);
} else {
valid = false;
}
if (!valid && !canForgeCommitter()) {
return false;
}
}
RevObject tagObject = tag.getObject();
if (tagObject instanceof RevCommit) {
if (!canCreateCommit(db, repo, (RevCommit) tagObject)) {
return false;
}
} else {
if (!canCreate(db, repo, tagObject)) {
return false;
}
}
// If the tag has a PGP signature, allow a lower level of permission
// than if it doesn't have a PGP signature.
//
if (tag.getFullMessage().contains("-----BEGIN PGP SIGNATURE-----\n")) {
return canPerform(Permission.CREATE_SIGNED_TAG);
}
return canPerform(Permission.CREATE_TAG);
} else {
return false;
}
}
private boolean canCreateCommit(ReviewDb db, Repository repo, RevCommit commit) {
if (canUpdate()) {
// If the user has push permissions, they can create the ref regardless
// of whether they are pushing any new objects along with the create.
return true;
} else if (isMergedIntoBranchOrTag(db, repo, commit)) {
// If the user has no push permissions, check whether the object is
// merged into a branch or tag readable by this user. If so, they are
// not effectively "pushing" more objects, so they can create the ref
// even if they don't have push permission.
return true;
}
return false;
}
private boolean isMergedIntoBranchOrTag(ReviewDb db, Repository repo, RevCommit commit) {
try (RevWalk rw = new RevWalk(repo)) {
List<Ref> refs = new ArrayList<>(repo.getRefDatabase().getRefs(Constants.R_HEADS).values());
refs.addAll(repo.getRefDatabase().getRefs(Constants.R_TAGS).values());
return projectControl.isMergedIntoVisibleRef(repo, db, rw, commit, refs);
} catch (IOException e) {
String msg =
String.format(
"Cannot verify permissions to commit object %s in repository %s",
commit.name(), projectControl.getProject().getNameKey());
log.error(msg, e);
}
return false;
}
/**
* Determines whether the user can delete the Git ref controlled by this object.
*
* @return {@code true} if the user specified can delete a Git ref.
*/
private boolean canDelete() {
if (!isProjectStatePermittingWrite() || (RefNames.REFS_CONFIG.equals(refName))) {
// Never allow removal of the refs/meta/config branch.
// Deleting the branch would destroy all Gerrit specific
// metadata about the project, including its access rules.
// If a project is to be removed from Gerrit, its repository
// should be removed first.
return false;
}
switch (getUser().getAccessPath()) {
case GIT:
return canPushWithForce() || canPerform(Permission.DELETE);
case JSON_RPC:
case REST_API:
case SSH_COMMAND:
case UNKNOWN:
case WEB_BROWSER:
default:
return getUser().getCapabilities().isAdmin_DoNotUse()
|| (isOwner() && !isForceBlocked(Permission.PUSH))
|| canPushWithForce()
|| canPerform(Permission.DELETE);
}
}
/** @return true if this user can forge the author line in a commit. */
public boolean canForgeAuthor() {
if (canForgeAuthor == null) {
canForgeAuthor = canPerform(Permission.FORGE_AUTHOR);
}
return canForgeAuthor;
}
/** @return true if this user can forge the committer line in a commit. */
public boolean canForgeCommitter() {
if (canForgeCommitter == null) {
canForgeCommitter = canPerform(Permission.FORGE_COMMITTER);
}
return canForgeCommitter;
}
/** @return true if this user can forge the server on the committer line. */
public boolean canForgeGerritServerIdentity() {
return canPerform(Permission.FORGE_SERVER);
}
/** @return true if this user can abandon a change for this ref */
boolean canAbandon() {
return canPerform(Permission.ABANDON);
}
/** @return true if this user can remove a reviewer for a change. */
boolean canRemoveReviewer() {
return canPerform(Permission.REMOVE_REVIEWER);
}
/** @return true if this user can view draft changes. */
boolean canViewDrafts() {
return canPerform(Permission.VIEW_DRAFTS);
}
/** @return true if this user can view private changes. */
boolean canViewPrivateChanges() {
return canPerform(Permission.VIEW_PRIVATE_CHANGES);
}
/** @return true if this user can publish draft changes. */
boolean canPublishDrafts() {
return canPerform(Permission.PUBLISH_DRAFTS);
}
/** @return true if this user can delete draft changes. */
boolean canDeleteDrafts() {
return canPerform(Permission.DELETE_DRAFTS);
}
/** @return true if this user can delete their own changes. */
boolean canDeleteOwnChanges() {
return canPerform(Permission.DELETE_OWN_CHANGES);
}
/** @return true if this user can edit topic names. */
boolean canEditTopicName() {
return canPerform(Permission.EDIT_TOPIC_NAME);
}
/** @return true if this user can edit hashtag names. */
boolean canEditHashtags() {
return canPerform(Permission.EDIT_HASHTAGS);
}
boolean canEditAssignee() {
return canPerform(Permission.EDIT_ASSIGNEE);
}
/** @return true if this user can force edit topic names. */
boolean canForceEditTopicName() {
return canForcePerform(Permission.EDIT_TOPIC_NAME);
}
/** All value ranges of any allowed label permission. */
List<PermissionRange> getLabelRanges(boolean isChangeOwner) {
List<PermissionRange> r = new ArrayList<>();
for (Map.Entry<String, List<PermissionRule>> e : relevant.getDeclaredPermissions()) {
if (Permission.isLabel(e.getKey())) {
int min = 0;
int max = 0;
for (PermissionRule rule : e.getValue()) {
if (projectControl.match(rule, isChangeOwner)) {
min = Math.min(min, rule.getMin());
max = Math.max(max, rule.getMax());
}
}
if (min != 0 || max != 0) {
r.add(new PermissionRange(e.getKey(), min, max));
}
}
}
return r;
}
/** The range of permitted values associated with a label permission. */
PermissionRange getRange(String permission) {
return getRange(permission, false);
}
/** The range of permitted values associated with a label permission. */
PermissionRange getRange(String permission, boolean isChangeOwner) {
if (Permission.hasRange(permission)) {
return toRange(permission, access(permission, isChangeOwner));
}
return null;
}
private static class AllowedRange {
private int allowMin;
private int allowMax;
private int blockMin = Integer.MIN_VALUE;
private int blockMax = Integer.MAX_VALUE;
void update(PermissionRule rule) {
if (rule.isBlock()) {
blockMin = Math.max(blockMin, rule.getMin());
blockMax = Math.min(blockMax, rule.getMax());
} else {
allowMin = Math.min(allowMin, rule.getMin());
allowMax = Math.max(allowMax, rule.getMax());
}
}
int getAllowMin() {
return allowMin;
}
int getAllowMax() {
return allowMax;
}
int getBlockMin() {
// ALLOW wins over BLOCK on the same project
return Math.min(blockMin, allowMin - 1);
}
int getBlockMax() {
// ALLOW wins over BLOCK on the same project
return Math.max(blockMax, allowMax + 1);
}
}
private PermissionRange toRange(String permissionName, List<PermissionRule> ruleList) {
Map<ProjectRef, AllowedRange> ranges = new HashMap<>();
for (PermissionRule rule : ruleList) {
ProjectRef p = relevant.getRuleProps(rule);
AllowedRange r = ranges.get(p);
if (r == null) {
r = new AllowedRange();
ranges.put(p, r);
}
r.update(rule);
}
int allowMin = 0;
int allowMax = 0;
int blockMin = Integer.MIN_VALUE;
int blockMax = Integer.MAX_VALUE;
for (AllowedRange r : ranges.values()) {
allowMin = Math.min(allowMin, r.getAllowMin());
allowMax = Math.max(allowMax, r.getAllowMax());
blockMin = Math.max(blockMin, r.getBlockMin());
blockMax = Math.min(blockMax, r.getBlockMax());
}
// BLOCK wins over ALLOW across projects
int min = Math.max(allowMin, blockMin + 1);
int max = Math.min(allowMax, blockMax - 1);
return new PermissionRange(permissionName, min, max);
}
/** True if the user has this permission. Works only for non labels. */
boolean canPerform(String permissionName) {
return canPerform(permissionName, false);
}
boolean canPerform(String permissionName, boolean isChangeOwner) {
return doCanPerform(permissionName, isChangeOwner, false);
}
/** True if the user is blocked from using this permission. */
public boolean isBlocked(String permissionName) {
return !doCanPerform(permissionName, false, true);
}
private boolean doCanPerform(String permissionName, boolean isChangeOwner, boolean blockOnly) {
List<PermissionRule> access = access(permissionName, isChangeOwner);
List<PermissionRule> overridden = relevant.getOverridden(permissionName);
Set<ProjectRef> allows = new HashSet<>();
Set<ProjectRef> blocks = new HashSet<>();
for (PermissionRule rule : access) {
if (rule.isBlock() && !rule.getForce()) {
blocks.add(relevant.getRuleProps(rule));
} else {
allows.add(relevant.getRuleProps(rule));
}
}
for (PermissionRule rule : overridden) {
blocks.remove(relevant.getRuleProps(rule));
}
blocks.removeAll(allows);
return blocks.isEmpty() && (!allows.isEmpty() || blockOnly);
}
/** True if the user has force this permission. Works only for non labels. */
private boolean canForcePerform(String permissionName) {
List<PermissionRule> access = access(permissionName);
List<PermissionRule> overridden = relevant.getOverridden(permissionName);
Set<ProjectRef> allows = new HashSet<>();
Set<ProjectRef> blocks = new HashSet<>();
for (PermissionRule rule : access) {
if (rule.isBlock()) {
blocks.add(relevant.getRuleProps(rule));
} else if (rule.getForce()) {
allows.add(relevant.getRuleProps(rule));
}
}
for (PermissionRule rule : overridden) {
if (rule.getForce()) {
blocks.remove(relevant.getRuleProps(rule));
}
}
blocks.removeAll(allows);
return blocks.isEmpty() && !allows.isEmpty();
}
/** True if for this permission force is blocked for the user. Works only for non labels. */
private boolean isForceBlocked(String permissionName) {
List<PermissionRule> access = access(permissionName);
List<PermissionRule> overridden = relevant.getOverridden(permissionName);
Set<ProjectRef> allows = new HashSet<>();
Set<ProjectRef> blocks = new HashSet<>();
for (PermissionRule rule : access) {
if (rule.isBlock()) {
blocks.add(relevant.getRuleProps(rule));
} else if (rule.getForce()) {
allows.add(relevant.getRuleProps(rule));
}
}
for (PermissionRule rule : overridden) {
if (rule.getForce()) {
blocks.remove(relevant.getRuleProps(rule));
}
}
blocks.removeAll(allows);
return !blocks.isEmpty();
}
/** Rules for the given permission, or the empty list. */
private List<PermissionRule> access(String permissionName) {
return access(permissionName, false);
}
/** Rules for the given permission, or the empty list. */
private List<PermissionRule> access(String permissionName, boolean isChangeOwner) {
List<PermissionRule> rules = effective.get(permissionName);
if (rules != null) {
return rules;
}
rules = relevant.getPermission(permissionName);
List<PermissionRule> mine = new ArrayList<>(rules.size());
for (PermissionRule rule : rules) {
if (projectControl.match(rule, isChangeOwner)) {
mine.add(rule);
}
}
if (mine.isEmpty()) {
mine = Collections.emptyList();
}
effective.put(permissionName, mine);
return mine;
}
ForRef asForRef() {
return new ForRefImpl();
}
private class ForRefImpl extends ForRef {
@Override
public ForRef user(CurrentUser user) {
return forUser(user).asForRef().database(db);
}
@Override
public ForChange change(ChangeData cd) {
try {
return cd.changeControl().forUser(getUser()).asForChange(cd, db);
} catch (OrmException e) {
return FailedPermissionBackend.change("unavailable", e);
}
}
@Override
public ForChange change(ChangeNotes notes) {
Project.NameKey project = getProjectControl().getProject().getNameKey();
Change change = notes.getChange();
checkArgument(
project.equals(change.getProject()),
"expected change in project %s, not %s",
project,
change.getProject());
return getProjectControl().controlFor(notes).asForChange(null, db);
}
@Override
public void check(RefPermission perm) throws AuthException, PermissionBackendException {
if (!can(perm)) {
throw new AuthException(perm.describeForException() + " not permitted");
}
}
@Override
public Set<RefPermission> test(Collection<RefPermission> permSet)
throws PermissionBackendException {
EnumSet<RefPermission> ok = EnumSet.noneOf(RefPermission.class);
for (RefPermission perm : permSet) {
if (can(perm)) {
ok.add(perm);
}
}
return ok;
}
private boolean can(RefPermission perm) throws PermissionBackendException {
switch (perm) {
case READ:
return isVisible();
case CREATE:
// TODO This isn't an accurate test.
return canPerform(perm.permissionName().get());
case DELETE:
return canDelete();
case UPDATE:
return canUpdate();
case FORCE_UPDATE:
return canForceUpdate();
case FORGE_AUTHOR:
return canForgeAuthor();
case FORGE_COMMITTER:
return canForgeCommitter();
case FORGE_SERVER:
return canForgeGerritServerIdentity();
case CREATE_CHANGE:
return canUpload();
}
throw new PermissionBackendException(perm + " unsupported");
}
}
}