[Zope3-checkins] SVN: Zope3/trunk/doc/security/SecurityTarget.tex walked through the remaining comments and clarified all issues.

Christian Zagrodnick cz at gocept.com
Fri Apr 21 05:38:13 EDT 2006


Log message for revision 67199:
  walked through the remaining comments and clarified all issues.
  
  

Changed:
  U   Zope3/trunk/doc/security/SecurityTarget.tex

-=-
Modified: Zope3/trunk/doc/security/SecurityTarget.tex
===================================================================
--- Zope3/trunk/doc/security/SecurityTarget.tex	2006-04-21 08:24:00 UTC (rev 67198)
+++ Zope3/trunk/doc/security/SecurityTarget.tex	2006-04-21 09:38:13 UTC (rev 67199)
@@ -247,7 +247,7 @@
 %___________________________________________________________________________
 
 
-\subsection{Logical scope and boundary of the TOE}
+\section{Logical scope and boundary of the TOE}
 
 The TOE logical boundary is defined by the following security-relevant
 subsystems provided by the TOE:
@@ -303,10 +303,7 @@
   (Content) Objects & 
   Generic objects (instances of Python classes) that
   are stored and controlled by Zope and carry
-  information that is to be protected. Objects are
-  stored in a connected manner that is typically
-  hierarchical and allows the derivation of
-  information by the objects context. \\
+  information that is to be protected. \\
   \bottomrule
   \caption{Primary Assets}
   \label{tab-assets}
@@ -372,10 +369,21 @@
   \label{tab-sec-assets}
 
 \end{longtable}
+
 %___________________________________________________________________________
+\section{Objects}
 
-\section{Subject}
+Objects are defined by both Zope and applications running on Zope. They are
+used for storing data and providing functionality. 
 
+Objects are stored in a hierarchy (i.e. a tree). Therefore for every object
+you can determine its ancestors and descendants.  The object's place in the
+hierarchy is called ``context''. Given an object, additional information can
+be retrieved from its context.
+
+%___________________________________________________________________________
+\section{Subjects}
+
 Zope has a concept of interactions, which model the interaction of one or more
 users with the system.  An interaction keeps track of the users that are
 participating in the interaction as ``participations''.  In the TOE,
@@ -561,10 +569,10 @@
    \\
   
 
-  T.RIP
+  T.Inconsistent
    & 
   An attacker might try to make the system use
-  residual information for deciding to allow
+  inconsistent information for deciding to allow
   or deny access to an operation to gain more
   access than intended.
    & 
@@ -654,16 +662,12 @@
   other principals.
   
   A special group of system administrators can be configured using ZCML to
-  create a set of initial users that have all permissions, including the
-  permisisons mapped to the ``Share'' privilege.  %% XXX
+  create a set of initial users that have all permissions. This also includes
+  the permissions mapped to the ``Share'' privilege and any other permission
+  that is not mapped to a privilege.
 
-  % ***Jim
-  % Note that these adminstrors can have permissions that can't be granted.
-  % These users have all permissions and not all permissions need be mapped
-  % to privileges.
   \\
 
-
   O.Audit
    & 
   The TOE will provide the means of recording any
@@ -708,7 +712,7 @@
   For example, we can make it easier to access the system to perform operations
   whose potential negative impact is low, but make it more difficult to access
   the system in a way that allows operations with high negative impact.
-  (Especially timed authentification and identification allow to provide
+  (Especially timed authentication and identification allow to provide
   functions to unauthenticated or unidentified users with the option to
   identify or authenticate as soon as the user wants to use a more critical
   function.)
@@ -717,7 +721,6 @@
   \caption{Security Objectives for the TOE}
 \end{longtable}
 
-\marginpar{Has anyone implemented time-based auth? -- Jim}
 
 %___________________________________________________________________________
 
@@ -881,7 +884,7 @@
 \begin{description}
 
   \item[FDP{\_}ACC.2.1 ] The TSF shall enforce the \emph{Zope access control
-    policy} on 1.  \emph{interactions and objects} and 2. all operations among
+    policy} on 1. \emph{interactions and objects} and 2. all operations among
     subjects and objects covered by the SFP.
 
   \item[FDP{\_}ACC.2.2] The TSF shall ensure that all operations between any
@@ -925,7 +928,7 @@
 
 \item If the object does not support sharing, access is determined by checking
 the privileges of the next object in the chain of ancestors that supports
-sharing. \marginpar{``Ancestors'' is not defined -- jim/zagy}
+sharing. 
 
 \item If the object does not support sharing and has no ancestors, then access
 is denied.
@@ -936,16 +939,16 @@
 
 \item[FDP{\_}ACF.1.3]
 
-The TSF shall explicitly authorise access of subjects to
-objects based on the following additional rules: \emph{none}
-\marginpar{Missing? -- jim}
+The TSF shall explicitly authorise access of subjects to objects based on the
+following additional rules: \emph{There are no additional rules.}
 
+
 \item[FDP{\_}ACF.1.4]
 
-The TSF shall explicitly deny access of subjects to objects
-based on the following additional rules: \emph{none}
-\marginpar{Missing? -- jim}
+The TSF shall explicitly deny access of subjects to objects based on the
+following additional rules: \emph{There are no additional rules.}
 
+
 \end{description}
 
 %___________________________________________________________________________
@@ -1000,11 +1003,7 @@
 
 \end{itemize}
 
-\marginpar{
-Interesting. :)  I wonder who's gonna implement this.
-Maybe we need to to-do list. -- jim}
 
-
 \end{description}
 
 
@@ -1038,11 +1037,13 @@
 unauthenticated principal.}
 
 \item[Note] It is possible to deny all operations to the anonymous
-principal. This means that a user must login before any operations may
-be performed on their behalf. This fulfills the terms of FIA{\_}UAU.2
-\marginpar{If authenticating is an operation too denying all operations means
-nobody can login?! -- zagy}
+principal. This means that all users must login before any operations may
+be performed on their behalf. Certain authentication methods require access to
+operations on the Zope server and will not work if all operations are denied.
+However HTTP basic auth does not require access to operations on the server
+and therefore is always available.  This fulfills the terms of FIA{\_}UAU.2.
 
+
 \item[FIA{\_}UAU.1.2 ]
 
 
@@ -1092,11 +1093,10 @@
 
 \emph{Note:} It is possible to deny all operations to the anonymous
 principal. This means that a user must login before any operations may
-be performed on their behalf. This fulfills the terms of FIA\_UID.2
-\marginpar{See above regarding nobody can authenticate\ldots -- zagy}
+be performed on their behalf. The restrictions mentioned in FIA\_UAU.1.1 apply
+as well.  This fulfills the terms of FIA\_UID.2
 
 
-
 \item[FIA{\_}UID.1.2 ]
 
 
@@ -1166,7 +1166,19 @@
     The TSF shall enforce the \emph{Zope access control policy} to restrict the
     ability to \emph{query, modify, delete, and add} the security
     attributes \emph{privilege grants} to \emph{users granted the ``Sharing''
-    privilege}.
+    p
+    rivilege}.
+\item[FMT{\_}MSA.1.1.users]
+    The TSF shall enforce the \emph{Zope access control policy} to restrict the
+    ability to \emph{query, modify, delete, and add} the security
+    attributes \emph{principals} to \emph{users in the administrators
+    group}.
+
+\item[FMT{\_}MSA.1.1.groups]
+    The TSF shall enforce the \emph{Zope access control policy} to restrict the
+    ability to \emph{query, modify, delete, and add} the security
+    attributes \emph{groups} to \emph{users in the administrators group}.
+
 \end{description}
 
 \minisec{FMT{\_}MSA.2 Secure security attributes}
@@ -1177,7 +1189,6 @@
 
     The TSF shall ensure that only secure values are accepted for security
     attributes.
-    \marginpar{Hm. I wonder what that means. :) -- jim}
 \end{description}
 
 %___________________________________________________________________________
@@ -1192,13 +1203,11 @@
 
 The TSF shall enforce the \emph{Zope access control policy} to provide 
 \emph{inherited} default values for security attributes that are used to 
-enforce the SFP.
-\marginpar{
-define inherited? Also, granting everything to the creator?  BTW
-granting sharing is equivalent to granting everything, since one you have
-sharing, you can get everything else. For this reason, we consider sharing
-equivalent to ownership. -- jim}
+enforce the SFP. 
 
+\item[Note:] On creation of an object the creator is granted all privileges.
+  Additional grants are copied from the next object in the chain of ancestors
+  that supports sharing.
 
 \item[FMT{\_}MSA.3.2 ]
 
@@ -1221,7 +1230,6 @@
     The TSF shall maintain the roles:
 \begin{description}
 \item[application-defined roles,]
-  \marginpar{XXX nothing to say? -- zagy}
 
 \item[administration role]
 
@@ -1369,8 +1377,7 @@
   \item The operating system is Linux. All known security patches must have
     been installed.
 
-  \item The Python Version is 2.4.2 
-    \marginpar{You might double check the schedule for 2.4.3. -- jim}
+  \item The Python Version is 2.4.3
 
   \item The ZODB storage is FileStorage or FileStorage through a ZEO server.
 
@@ -1413,9 +1420,6 @@
 is allowed.  Any non-basic results of operations performed through security
 proxies are security proxied.
 
-\marginpar{I hope there is more layer, like definition of basic objects and
-mention of special case of attribute access. Maybe even ``untrusted
-interpreter''. -- jim}
 %___________________________________________________________________________
 
 
@@ -1423,14 +1427,10 @@
 \subsection{Authentication}
 
 Within the scope of this certification, Zope provides authentication using
-HTTP basic authentication and a cookie-based authentication mechanism.
+HTTP basic authentication and a session/cookie-based authentication mechanism.
 Credentials can be configured and stored using the configuration system and/or
 in the ZODB using the ``Pluggable Authentication Utility''.
-\marginpar{
-Note that afaik, we don't have cookie auth per se. We have session auth and 
-often use cookies to keep track of sessions.
--- jim
-}
+
 %___________________________________________________________________________
 
 
@@ -1515,11 +1515,11 @@
 
 The publisher is extensible to allow support for further protocols.
 
-To support FIA{\_}UAU.1 the implementation of a protocol includes the ability to
-communicate with a user for requesting authentication data. The ability to
+To support FIA{\_}UAU.1 the implementation of a protocol includes the ability
+to communicate with a user for requesting authentication data. The ability to
 present credentials is specific to the used protocol and clients. By default
-HTTP basic auth, cookie authentication and FTP authentication are supported.
-\marginpar{See remark above wrt cookies --jim}
+HTTP basic auth, session/cookie authentication and FTP authentication are
+supported.
 
 To support FIA{\_}USB.1, the publisher also returns the credentials to Zope and
 calls the authentication subsystem to validate this data and binds the
@@ -1622,23 +1622,23 @@
 
   \begin{longtable}{rRRRRRRRRRRRRRRR}
     \toprule
-              & T.IA  & T.Perm &T.Operation&T.AuditFake& T.RIP&T.Transaction&T.Timestamps & T.Host & A.OS & A.Admin & A.Network & A.Client & A.Credential  \\
+              & T.IA  & T.Perm &T.Operation&T.AuditFake& T.Inconsistent&T.Transaction&T.Timestamps & T.Host & A.OS & A.Admin & A.Network & A.Client & A.Credential  \\
     \midrule\endhead
-O.IA         &  \oh  &       &            &            &      &             &             &        &      &       \\
-O.Delegation &       &   \oh &            &            &      &             &             &        &      &        \\
-O.Audit      & \oh   &   \oh &     \oh    &            &      &             &             &        &      &        \\
-O.Protect    &       &       &            &    \oh     &      &             &             &        & \oh  &        \\
-O.Access     &       &       &      \oh   &            &      &    \oh      &             &   \oh  &      &        \\
-O.Integrity  &       &       &            &            &  \oh &             &             &        &      &        \\
-O.Attributes &       &       &            &            &  \oh &             &             &        &      &        \\
-O.ManageRisk &   \oh &       &            &            &      &             &             &        &      &        \\
+O.IA         &  \oh  &       &            &            &               &             &             &        &      &       \\
+O.Delegation &       &   \oh &            &            &               &             &             &        &      &        \\
+O.Audit      & \oh   &   \oh &     \oh    &            &               &             &             &        &      &        \\
+O.Protect    &       &       &            &    \oh     &               &             &             &        & \oh  &        \\
+O.Access     &       &       &      \oh   &            &               &    \oh      &             &   \oh  &      &        \\
+O.Integrity  &       &       &            &            &  \oh          &             &             &        &      &        \\
+O.Attributes &       &       &            &            &  \oh          &             &             &        &      &        \\
+O.ManageRisk &   \oh &       &            &            &               &             &             &        &      &        \\
 \midrule
-OE.OS        &       &       &            &            &      &             &    \oh      &        &  \oh &         &         &            &          \\
-OE.Trust     &       &       &            &            &      &             &             &        &      &  \oh    &         &            &            \\
-OE.Auditlog  &       &       &            &            &      &             &             &        & \oh  &         &         &            &                   \\  
-OE.Network   &       &       &            &            &      &             &             &        &      &         &  \oh    &            &                   \\   
-OE.Client    &       &       &            &            &      &             &             &        &      &         &         &    \oh     &                   \\
-OE.Credential&       &       &            &            &      &             &             &        &      &         &         &            &    \oh    \\ 
+OE.OS        &       &       &            &            &               &             &    \oh      &        &  \oh &         &         &            &          \\
+OE.Trust     &       &       &            &            &               &             &             &        &      &  \oh    &         &            &            \\
+OE.Auditlog  &       &       &            &            &               &             &             &        & \oh  &         &         &            &                   \\  
+OE.Network   &       &       &            &            &               &             &             &        &      &         &  \oh    &            &                   \\   
+OE.Client    &       &       &            &            &               &             &             &        &      &         &         &    \oh     &                   \\
+OE.Credential&       &       &            &            &               &             &             &        &      &         &         &            &    \oh    \\ 
 \bottomrule
   \caption{Mapping of Threats and Assumptions to Security Objectives}
   \label{tab-SOR}
@@ -1677,14 +1677,13 @@
   managing functions are also objects and therefore protected.
 
   \item[O.Integrity:] This security objective is necessary to counter the
-  threat \textbf{T.RIP} because it prevents that any data will be written if
-  an unhandled error occurs.
+    threat \textbf{T.Inconsistent} because it prevents that any data will be
+    written if an unhandled error occurs.
   
   \item[O.Attributes:] This security objective is necessary to counter the
-  threat \textbf{T.RIP} because it
-  prevents an attacker form setting inconsistent security attributes from
-  which he could gain more access than intended.
-  % XXX rip was removed!
+    threat \textbf{T.Inconsistent} because it prevents an attacker from
+    setting inconsistent security attributes from which he could gain more
+    access than intended.
 
   \item[O.ManageRisk:] This security objective is necessary to counter the
   threat \textbf{T.IA} because it makes it less likely that an attacker
@@ -1733,16 +1732,15 @@
 FAU\_GEN.2                  &      &              & \oh     &           &          &             &              &              \\
 FDP\_ACC.2                  &      & \oh          &         &           & \oh      &             &              &              \\
 FDP\_ACF.1                  &      &              &         &           &  \oh     &             &              &              \\
-FDP\_RIP.1                  &      &              &         &           &          &             &  \oh         &              \\
 FDP\_ROL.2\_Transactions    &      &              &         &           &          &   \oh       &              &              \\
 FIA\_AFL\_z.1               &      &              &         &   \oh     &          &             &              &              \\
 FIA\_ATD.1                  & \oh  &  \oh         &   \oh   &           & \oh      &             &              &              \\
 FIA\_UAU.1                  & \oh  &              &         &           &          &             &              &              \\
-FIA\_UAU.5                  & \oh  &              &         &           &          &             &              & \oh          \\
-FIA\_UAU.6                  & \oh  &              &         &           &          &             &              & \oh          \\
+FIA\_UAU.5                  & \oh  &              &         &           &          &             &              &              \\
+FIA\_UAU.6                  & \oh  &              &         &           &          &             &              &              \\
 FIA\_UID.1                  & \oh  &              &         &           &          &             &              &              \\
 FIA\_USB.1                  & \oh  &              &         &           &          &             &              &              \\
-FMT\_MOF.1                  &      &              &         &  \oh      &          &             &              & \oh          \\
+FMT\_MOF.1                  &      &              &         &  \oh      &          &             &              &              \\
 FMT\_MSA.1                  & \oh  &  \oh         &         &           &          &             &              &              \\
 FMT\_MSA.2                  &      &              &         &           &          &             &  \oh         &              \\  
 FMT\_MSA.3                  &      &              &         & \oh       &          &             &  \oh         &              \\
@@ -1765,7 +1763,6 @@
 FAU\_GEN.2                  &   FAU\_GEN.1, FIA\_UID.1 \\
 FDP\_ACC.2                  &   FDP\_ACF.1 \\
 FDP\_ACF.1                  &   FDP\_ACC.1, FMT\_MSA.3 \\
-FDP\_RIP.1                  &   -- \\
 FDP\_ROL.2\_Transactions    &   -- \\
 FIA\_AFL\_z.1               &   FIA\_UAU.1 \\
 FIA\_ATD.1                  &   -- \\
@@ -1813,9 +1810,9 @@
             perform an operation, he might get the chance to authenticate with
             other credentials. (FIA\_UAU.6)
 
-            If the credentials stored at the user agent expire (e.g. cookies in
-            a web browser), the user will be asked to represent his credentials
-            before performing any further operation. (FIA\_UAU.6)
+            If the credentials stored at the user agent expire (e.g.  cookies
+            in a web browser), the user will be asked to represent his
+            credentials before performing any further operation. (FIA\_UAU.6)
 
         \item[Binding users to the correct principals:]
 
@@ -1919,21 +1916,7 @@
     (FMT\_MSA.3)
 
 \subsection{O.ManageRisk --- Provide choice of flexibility versus security}
-
-    To manage the risk of using stronger authentication schemes for sensitive
-    operations in opposition of weaker authentication schemes for less sensitive
-    operations, the TOE allows a selection of the authentication system to
-    happen. (FIA\_UAU.5) To increase a users level of access for accessing more
-    sensitive operations, a reauthentication may be needed. (FIA\_UAU.6)
     
-    The decision what authentication schemes are needed for which operations
-    can be managed by authorised administrators. (FMT\_MOF.1)
-    \marginpar{
-I don't understand this.  Auth schemes don't depend on the operations
-being performed. -- jim
-}
-
-    
     Additionally code can be run either within the trusted or untrusted
     security domains of the TOE. Installing code in the trusted security domain
     requires an external entity that has access to the physical secure host to
@@ -1954,7 +1937,6 @@
 FAU\_GEN.2          &            &                &               & \oh      &               &                        &                    &                 &                    \\   
 FDP\_ACC.2          & \oh        &                &               &          &               &                        & \oh                &                 &                    \\   
 FDP\_ACF.1          &            &                &  \oh          &          &               &                        &                    &                 &                    \\   
-FDP\_RIP.1          &            &                &               &          & \oh           &                        &                    &                 &                    \\   
 FDP\_ROL.2\_TRANSACTIONS
                     & \oh        &                &  \oh          &          &               & \oh                    &                    &                 &                    \\   
 FIA\_AFL\_z.1       &            &  \oh           &               &          &               &                        & \oh                &                 &                    \\   
@@ -1983,15 +1965,14 @@
 
 \minisec{FDP\_ACC.2 --- Complete Access Control}
 
-\marginpar{XXX is there a single point of entry? -- theuni}
-
 Complete access control is achieved by the \textbf{Protection} subsystem. The
 \textbf{Publication} subsystem serves as a single entry point to the Zope 3
-application which wraps all published objects into security proxies. The
-transient nature of security proxies then covers that all subsequent accesses
-are security proxied as well. Thereby all operations among those objects are
-covered by the protection subsytem which enforces the Zope access control policy.
+application which wraps all published objects into security proxies.
 
+When an interaction accesses a proxied object, the protection subsystem
+becomes effective and regulates access.
+
+
 \minisec{FDP\_ROL.2\_TRANSACTIONS --- Advanced Rollback}
 
 The \textbf{Transaction management} of ZODB allows rollback of transaction. The
@@ -2073,12 +2054,8 @@
 
 \minisec{FMT\_MSA.1 --- Management of Security Attributes}
 
-The management of security attributes is provided by the \textbf{Configuration}
-subsystem. This happens by using the same API as for FMT\_MOF.1 including the
-different ways of accessing this API.
-\marginpar{I'm confused -- jim}
+Managing security attributes is a normal operation and therefore protected.
 
-
 \minisec{FMT\_MSA.2 --- Secure Security Attributes}
 
 The \textbf{Configuration} subsystems API for managing security functions and



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