Make document signatures visible to only document owners and signers

Summary:
Ref T3116. Currently signatures are visible to anyone, but they should be more private than that. Instead, you can see a signature if:

  - It's a signature on a document you can edit; or
  - it's your signature.

I'm going to lock down the signatures page a bit in general, but this makes sure that the root policy is correct.

Test Plan:
  - Signed a document.
  - Viewed signatures of a document.

Reviewers: chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T3116

Differential Revision: https://secure.phabricator.com/D9764

src/applications/legalpad/query/LegalpadDocumentSignatureQuery.php

@@ -46,9 +46,32 @@ final class LegalpadDocumentSignatureQuery
       $this->buildOrderClause($conn_r),
       $this->buildLimitClause($conn_r));
 
-    $documents = $table->loadAllFromArray($data);
+    $signatures = $table->loadAllFromArray($data);
 
-    return $documents;
+    return $signatures;
+  }
+
+  protected function willFilterPage(array $signatures) {
+    $document_phids = mpull($signatures, 'getDocumentPHID');
+
+    $documents = id(new LegalpadDocumentQuery())
+      ->setParentQuery($this)
+      ->setViewer($this->getViewer())
+      ->withPHIDs($document_phids)
+      ->execute();
+    $documents = mpull($documents, null, 'getPHID');
+
+    foreach ($signatures as $key => $signature) {
+      $document_phid = $signature->getDocumentPHID();
+      $document = idx($documents, $document_phid);
+      if ($document) {
+        $signature->attachDocument($document);
+      } else {
+        unset($signatures[$key]);
+      }
+    }
+
+    return $signatures;
   }
 
   protected function buildWhereClause($conn_r) {
@@ -56,35 +79,35 @@ final class LegalpadDocumentSignatureQuery
 
     $where[] = $this->buildPagingClause($conn_r);
 
-    if ($this->ids) {
+    if ($this->ids !== null) {
       $where[] = qsprintf(
         $conn_r,
         'id IN (%Ld)',
         $this->ids);
     }
 
-    if ($this->documentPHIDs) {
+    if ($this->documentPHIDs !== null) {
       $where[] = qsprintf(
         $conn_r,
         'documentPHID IN (%Ls)',
         $this->documentPHIDs);
     }
 
-    if ($this->signerPHIDs) {
+    if ($this->signerPHIDs !== null) {
       $where[] = qsprintf(
         $conn_r,
         'signerPHID IN (%Ls)',
         $this->signerPHIDs);
     }
 
-    if ($this->documentVersions) {
+    if ($this->documentVersions !== null) {
       $where[] = qsprintf(
         $conn_r,
         'documentVersion IN (%Ld)',
         $this->documentVersions);
     }
 
-    if ($this->secretKeys) {
+    if ($this->secretKeys !== null) {
       $where[] = qsprintf(
         $conn_r,
         'secretKey IN (%Ls)',

src/applications/legalpad/storage/LegalpadDocumentSignature.php

@@ -14,6 +14,8 @@ final class LegalpadDocumentSignature
   protected $verified;
   protected $secretKey;
 
+  private $document = self::ATTACHABLE;
+
   public function getConfiguration() {
     return array(
       self::CONFIG_SERIALIZATION => array(
@@ -30,10 +32,22 @@ final class LegalpadDocumentSignature
   }
 
   public function isVerified() {
-    return $this->getVerified() != self::UNVERIFIED;
+    return ($this->getVerified() != self::UNVERIFIED);
   }
+
+  public function getDocument() {
+    return $this->assertAttached($this->document);
+  }
+
+  public function attachDocument(LegalpadDocument $document) {
+    $this->document = $document;
+    return $this;
+  }
+
+
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
+
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
@@ -43,12 +57,13 @@ final class LegalpadDocumentSignature
   public function getPolicy($capability) {
     switch ($capability) {
       case PhabricatorPolicyCapability::CAN_VIEW:
-        return PhabricatorPolicies::POLICY_USER;
+        return $this->getDocument()->getPolicy(
+          PhabricatorPolicyCapability::CAN_EDIT);
     }
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
-    return false;
+    return ($viewer->getPHID() == $this->getSignerPHID());
   }
 
   public function describeAutomaticCapability($capability) {