From 95ce1cb291324bdef3c790e367ba6ac8752c5f23 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Tue, 27 Apr 2021 10:26:01 +0200
Subject: [PATCH 06/10] NetworkPkg/IScsiDxe: assert that IScsiBinToHex() always
 succeeds
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RH-Author: Laszlo Ersek <lersek@redhat.com>
RH-MergeRequest: 3: NetworkPkg/IScsiDxe: fix IScsiHexToBin() security and functionality bugs [rhel-8.4.0.z]
RH-Commit: [6/10] b302b99312b327b9bf04ea408c638fa0e366d643
RH-Bugzilla: 1956676
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>

IScsiBinToHex() is called for encoding:

- the answer to the target's challenge; that is, CHAP_R;

- the challenge for the target, in case mutual authentication is enabled;
  that is, CHAP_C.

The initiator controls the size of both blobs, the sizes of their hex
encodings are correctly calculated in "RspLen" and "ChallengeLen".
Therefore the IScsiBinToHex() calls never fail; assert that.

Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3356
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Upstream: https://bugzilla.tianocore.org/show_bug.cgi?id=3356, c#17...c#22
---
 NetworkPkg/IScsiDxe/IScsiCHAP.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/NetworkPkg/IScsiDxe/IScsiCHAP.c b/NetworkPkg/IScsiDxe/IScsiCHAP.c
index 9e192ce292..dbe3c8ef46 100644
--- a/NetworkPkg/IScsiDxe/IScsiCHAP.c
+++ b/NetworkPkg/IScsiDxe/IScsiCHAP.c
@@ -391,6 +391,7 @@ IScsiCHAPToSendReq (
   UINT32                      RspLen;
   CHAR8                       *Challenge;
   UINT32                      ChallengeLen;
+  EFI_STATUS                  BinToHexStatus;
 
   ASSERT (Conn->CurrentStage == ISCSI_SECURITY_NEGOTIATION);
 
@@ -471,12 +472,13 @@ IScsiCHAPToSendReq (
     //
     // CHAP_R=<R>
     //
-    IScsiBinToHex (
-      (UINT8 *) AuthData->CHAPResponse,
-      ISCSI_CHAP_RSP_LEN,
-      Response,
-      &RspLen
-      );
+    BinToHexStatus = IScsiBinToHex (
+                       (UINT8 *) AuthData->CHAPResponse,
+                       ISCSI_CHAP_RSP_LEN,
+                       Response,
+                       &RspLen
+                       );
+    ASSERT_EFI_ERROR (BinToHexStatus);
     IScsiAddKeyValuePair (Pdu, ISCSI_KEY_CHAP_RESPONSE, Response);
 
     if (AuthData->AuthConfig->CHAPType == ISCSI_CHAP_MUTUAL) {
@@ -490,12 +492,13 @@ IScsiCHAPToSendReq (
       // CHAP_C=<C>
       //
       IScsiGenRandom ((UINT8 *) AuthData->OutChallenge, ISCSI_CHAP_RSP_LEN);
-      IScsiBinToHex (
-        (UINT8 *) AuthData->OutChallenge,
-        ISCSI_CHAP_RSP_LEN,
-        Challenge,
-        &ChallengeLen
-        );
+      BinToHexStatus = IScsiBinToHex (
+                         (UINT8 *) AuthData->OutChallenge,
+                         ISCSI_CHAP_RSP_LEN,
+                         Challenge,
+                         &ChallengeLen
+                         );
+      ASSERT_EFI_ERROR (BinToHexStatus);
       IScsiAddKeyValuePair (Pdu, ISCSI_KEY_CHAP_CHALLENGE, Challenge);
 
       Conn->AuthStep = ISCSI_CHAP_STEP_FOUR;
-- 
2.27.0