Re: [PATCH] CryptoPkg: Remove deprecated function usage in X509GetCommonName()

["Ye, Ting" <ting.ye@intel.com>]

Reviewed-by: Ye Ting <ting.ye@intel.com> 

-----Original Message-----
From: Long, Qin 
Sent: Thursday, May 24, 2018 4:11 PM
To: edk2-devel@lists.01.org
Cc: Ye, Ting <ting.ye@intel.com>; Michael.Turner@microsoft.com
Subject: [PATCH] CryptoPkg: Remove deprecated function usage in X509GetCommonName()

BZ#: https://bugzilla.tianocore.org/show_bug.cgi?id=923

X509_NAME_get_text_by_NID() used in X509GetCommonName() implementation is one legacy function which have various limitations. The returned data may be not usable  when the target cert contains multicharacter string type like a BMPString or a UTF8String.
This patch replaced the legacy function usage with more general
X509_NAME_get_index_by_NID() / X509_NAME_get_entry() APIs for X509 CommonName retrieving.

Tests: Validated the commonName retrieving with test certificates
       containing PrintableString or BMPString data.

Cc: Ye Ting <ting.ye@intel.com>
Cc: Michael Turner <Michael.Turner@microsoft.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Long Qin <qin.long@intel.com>
---
 CryptoPkg/Include/Library/BaseCryptLib.h          |  4 +-
 CryptoPkg/Library/BaseCryptLib/Pk/CryptX509.c     | 53 ++++++++++++++++++-----
 CryptoPkg/Library/BaseCryptLib/Pk/CryptX509Null.c |  4 +-
 3 files changed, 47 insertions(+), 14 deletions(-)

diff --git a/CryptoPkg/Include/Library/BaseCryptLib.h b/CryptoPkg/Include/Library/BaseCryptLib.h
index 027ea09feb..dc6aaf0635 100644
--- a/CryptoPkg/Include/Library/BaseCryptLib.h
+++ b/CryptoPkg/Include/Library/BaseCryptLib.h
@@ -4,7 +4,7 @@
   primitives (Hash Serials, HMAC, RSA, Diffie-Hellman, etc) for UEFI security
   functionality enabling.
 
-Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials  are licensed and made available under the terms and conditions of the BSD License  which accompanies this distribution.  The full text of the license may be found at @@ -2177,7 +2177,7 @@ X509GetSubjectName (
   @param[in]      Cert             Pointer to the DER-encoded X509 certificate.
   @param[in]      CertSize         Size of the X509 certificate in bytes.
   @param[out]     CommonName       Buffer to contain the retrieved certificate common
-                                   name string. At most CommonNameSize bytes will be
+                                   name string (UTF8). At most 
+ CommonNameSize bytes will be
                                    written and the string will be null terminated. May be
                                    NULL in order to determine the size buffer needed.
   @param[in,out]  CommonNameSize   The size in bytes of the CommonName buffer on input,
diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptX509.c b/CryptoPkg/Library/BaseCryptLib/Pk/CryptX509.c
index 56e66308ae..c137df357f 100644
--- a/CryptoPkg/Library/BaseCryptLib/Pk/CryptX509.c
+++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptX509.c
@@ -1,7 +1,7 @@
 /** @file
   X.509 Certificate Handler Wrapper Implementation over OpenSSL.
 
-Copyright (c) 2010 - 2017, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2010 - 2018, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials  are licensed and made available under the terms and conditions of the BSD License  which accompanies this distribution.  The full text of the license may be found at @@ -303,7 +303,7 @@ _Exit:
   @param[in]      Cert             Pointer to the DER-encoded X509 certificate.
   @param[in]      CertSize         Size of the X509 certificate in bytes.
   @param[out]     CommonName       Buffer to contain the retrieved certificate common
-                                   name string. At most CommonNameSize bytes will be
+                                   name string (UTF8). At most 
+ CommonNameSize bytes will be
                                    written and the string will be null terminated. May be
                                    NULL in order to determine the size buffer needed.
   @param[in,out]  CommonNameSize   The size in bytes of the CommonName buffer on input,
@@ -332,13 +332,18 @@ X509GetCommonName (
   IN OUT  UINTN        *CommonNameSize
   )
 {
-  RETURN_STATUS  ReturnStatus;
-  BOOLEAN        Status;
-  X509           *X509Cert;
-  X509_NAME      *X509Name;
-  INTN           Length;
+  RETURN_STATUS    ReturnStatus;
+  BOOLEAN          Status;
+  X509             *X509Cert;
+  X509_NAME        *X509Name;
+  INT32            Index;
+  INTN             Length;
+  X509_NAME_ENTRY  *Entry;
+  ASN1_STRING      *EntryData;
+  UINT8            *UTF8Name;
 
   ReturnStatus = RETURN_INVALID_PARAMETER;
+  UTF8Name     = NULL;
 
   //
   // Check input parameters.
@@ -378,8 +383,8 @@ X509GetCommonName (
   //
   // Retrieve the CommonName information from X.509 Subject
   //
-  Length = (INTN) X509_NAME_get_text_by_NID (X509Name, NID_commonName, CommonName, (int)(*CommonNameSize));
-  if (Length < 0) {
+  Index = X509_NAME_get_index_by_NID (X509Name, NID_commonName, -1);  
+ if (Index < 0) {
     //
     // No CommonName entry exists in X509_NAME object
     //
@@ -388,10 +393,35 @@ X509GetCommonName (
     goto _Exit;
   }
 
-  *CommonNameSize = (UINTN)(Length + 1);
+  Entry = X509_NAME_get_entry (X509Name, Index);  if (Entry == NULL) {
+    //
+    // Fail to retrieve name entry data
+    //
+    *CommonNameSize = 0;
+    ReturnStatus    = RETURN_NOT_FOUND;
+    goto _Exit;
+  }
+
+  EntryData = X509_NAME_ENTRY_get_data (Entry);
+
+  Length = ASN1_STRING_to_UTF8 (&UTF8Name, EntryData);  if (Length < 0) 
+ {
+    //
+    // Fail to convert the commonName string
+    //
+    *CommonNameSize = 0;
+    ReturnStatus    = RETURN_INVALID_PARAMETER;
+    goto _Exit;
+  }
+
   if (CommonName == NULL) {
+    *CommonNameSize = Length + 1;
     ReturnStatus = RETURN_BUFFER_TOO_SMALL;
   } else {
+    *CommonNameSize = MIN ((UINTN)Length, *CommonNameSize - 1) + 1;
+    CopyMem (CommonName, UTF8Name, *CommonNameSize - 1);
+    CommonName[*CommonNameSize - 1] = '\0';
     ReturnStatus = RETURN_SUCCESS;
   }
 
@@ -402,6 +432,9 @@ _Exit:
   if (X509Cert != NULL) {
     X509_free (X509Cert);
   }
+  if (UTF8Name != NULL) {
+    OPENSSL_free (UTF8Name);
+  }
 
   return ReturnStatus;
 }
diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptX509Null.c b/CryptoPkg/Library/BaseCryptLib/Pk/CryptX509Null.c
index d00f38daa8..d86c784a7f 100644
--- a/CryptoPkg/Library/BaseCryptLib/Pk/CryptX509Null.c
+++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptX509Null.c
@@ -2,7 +2,7 @@
   X.509 Certificate Handler Wrapper Implementation which does not provide
   real capabilities.
 
-Copyright (c) 2012 - 2014, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2012 - 2018, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials  are licensed and made available under the terms and conditions of the BSD License  which accompanies this distribution.  The full text of the license may be found at @@ -135,7 +135,7 @@ X509GetSubjectName (
   @param[in]      Cert             Pointer to the DER-encoded X509 certificate.
   @param[in]      CertSize         Size of the X509 certificate in bytes.
   @param[out]     CommonName       Buffer to contain the retrieved certificate common
-                                   name string. At most CommonNameSize bytes will be
+                                   name string (UTF8). At most 
+ CommonNameSize bytes will be
                                    written and the string will be null terminated. May be
                                    NULL in order to determine the size buffer needed.
   @param[in,out]  CommonNameSize   The size in bytes of the CommonName buffer on input,
--
2.16.1.windows.1