NetworkPkg TcpDxe: SECURITY PATCH CVE-2023-45236

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4541
REF: https://www.rfc-editor.org/rfc/rfc1948.txt
REF: https://www.rfc-editor.org/rfc/rfc6528.txt
REF: https://www.rfc-editor.org/rfc/rfc9293.txt

Bug Overview:
PixieFail Bug #8
CVE-2023-45236
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

Updates TCP ISN generation to use a cryptographic hash of the
connection's identifying parameters and a secret key.
This prevents an attacker from guessing the ISN used for some other
connection.

This is follows the guidance in RFC 1948, RFC 6528, and RFC 9293.

RFC: 9293 Section 3.4.1.  Initial Sequence Number Selection

   A TCP implementation MUST use the above type of "clock" for clock-
   driven selection of initial sequence numbers (MUST-8), and SHOULD
   generate its initial sequence numbers with the expression:

   ISN = M + F(localip, localport, remoteip, remoteport, secretkey)

   where M is the 4 microsecond timer, and F() is a pseudorandom
   function (PRF) of the connection's identifying parameters ("localip,
   localport, remoteip, remoteport") and a secret key ("secretkey")
   (SHLD-1).  F() MUST NOT be computable from the outside (MUST-9), or
   an attacker could still guess at sequence numbers from the ISN used
   for some other connection.  The PRF could be implemented as a
   cryptographic hash of the concatenation of the TCP connection
   parameters and some secret data.  For discussion of the selection of
   a specific hash algorithm and management of the secret key data,
   please see Section 3 of [42].

   For each connection there is a send sequence number and a receive
   sequence number.  The initial send sequence number (ISS) is chosen by
   the data sending TCP peer, and the initial receive sequence number
   (IRS) is learned during the connection-establishing procedure.

   For a connection to be established or initialized, the two TCP peers
   must synchronize on each other's initial sequence numbers.  This is
   done in an exchange of connection-establishing segments carrying a
   control bit called "SYN" (for synchronize) and the initial sequence
   numbers.  As a shorthand, segments carrying the SYN bit are also
   called "SYNs".  Hence, the solution requires a suitable mechanism for
   picking an initial sequence number and a slightly involved handshake
   to exchange the ISNs.

Cc: Saloni Kasbekar <saloni.kasbekar@intel.com>
Cc: Zachary Clark-williams <zachary.clark-williams@intel.com>

Signed-off-by: Doug Flick [MSFT] <doug.edk2@gmail.com>
Reviewed-by: Saloni Kasbekar <saloni.kasbekar@intel.com>

NetworkPkg/TcpDxe/TcpFunc.h

@@ -2,7 +2,7 @@
   Declaration of external functions shared in TCP driver.
 
   Copyright (c) 2009 - 2014, Intel Corporation. All rights reserved.<BR>
-
+  Copyright (c) Microsoft Corporation
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -36,8 +36,11 @@ VOID
 
   @param[in, out]  Tcb               Pointer to the TCP_CB of this TCP instance.
 
+  @retval EFI_SUCCESS             The operation completed successfully
+  @retval others                  The underlying functions failed and could not complete the operation
+
 **/
-VOID
+EFI_STATUS
 TcpInitTcbLocal (
   IN OUT TCP_CB  *Tcb
   );
@@ -128,17 +131,6 @@ TcpCloneTcb (
   IN TCP_CB  *Tcb
   );
 
-/**
-  Compute an ISS to be used by a new connection.
-
-  @return The result ISS.
-
-**/
-TCP_SEQNO
-TcpGetIss (
-  VOID
-  );
-
 /**
   Get the local mss.
 
@@ -202,8 +194,11 @@ TcpFormatNetbuf (
   @param[in, out]  Tcb          Pointer to the TCP_CB that wants to initiate a
                                 connection.
 
+  @retval EFI_SUCCESS             The operation completed successfully
+  @retval others                  The underlying functions failed and could not complete the operation
+
 **/
-VOID
+EFI_STATUS
 TcpOnAppConnect (
   IN OUT TCP_CB  *Tcb
   );