CryptoPkg/Library/BaseCryptLib/Pk/CryptAuthenticode.c

   1 /** @file
   2   Authenticode Portable Executable Signature Verification over OpenSSL.
   3
   4 Copyright (c) 2011 - 2012, Intel Corporation. All rights reserved.<BR>
   5 This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include "InternalCryptLib.h"
  16
  17 #include <openssl/objects.h>
  18 #include <openssl/x509.h>
  19 #include <openssl/pkcs7.h>
  20
  21
  22 /**
  23   Verifies the validility of a PE/COFF Authenticode Signature as described in "Windows
  24   Authenticode Portable Executable Signature Format".
  25
  26   If AuthData is NULL, then return FALSE.
  27   If ImageHash is NULL, then return FALSE.
  28
  29   @param[in]  AuthData     Pointer to the Authenticode Signature retrieved from signed
  30                            PE/COFF image to be verified.
  31   @param[in]  DataSize     Size of the Authenticode Signature in bytes.
  32   @param[in]  TrustedCert  Pointer to a trusted/root certificate encoded in DER, which
  33                            is used for certificate chain verification.
  34   @param[in]  CertSize     Size of the trusted certificate in bytes.
  35   @param[in]  ImageHash    Pointer to the original image file hash value. The procudure
  36                            for calculating the image hash value is described in Authenticode
  37                            specification.
  38   @param[in]  HashSize     Size of Image hash value in bytes.
  39
  40   @retval  TRUE   The specified Authenticode Signature is valid.
  41   @retval  FALSE  Invalid Authenticode Signature.
  42
  43 **/
  44 BOOLEAN
  45 EFIAPI
  46 AuthenticodeVerify (
  47   IN  CONST UINT8  *AuthData,
  48   IN  UINTN        DataSize,
  49   IN  CONST UINT8  *TrustedCert,
  50   IN  UINTN        CertSize,
  51   IN  CONST UINT8  *ImageHash,
  52   IN  UINTN        HashSize
  53   )
  54 {
  55   BOOLEAN      Status;
  56   PKCS7        *Pkcs7;
  57   CONST UINT8  *OrigAuthData;
  58   UINT8        *SpcIndirectDataContent;
  59   UINT8        Asn1Byte;
  60   UINTN        ContentSize;
  61
  62   //
  63   // Check input parameters.
  64   //
  65   if ((AuthData == NULL) || (TrustedCert == NULL) || (ImageHash == NULL)) {
  66     return FALSE;
  67   }
  68
  69   if ((DataSize > INT_MAX) || (CertSize > INT_MAX) || (HashSize > INT_MAX)) {
  70     return FALSE;
  71   }
  72
  73   Status       = FALSE;
  74   Pkcs7        = NULL;
  75   OrigAuthData = AuthData;
  76
  77   //
  78   // Retrieve & Parse PKCS#7 Data (DER encoding) from Authenticode Signature
  79   //
  80   Pkcs7 = d2i_PKCS7 (NULL, &AuthData, (int)DataSize);
  81   if (Pkcs7 == NULL) {
  82     goto _Exit;
  83   }
  84
  85   //
  86   // Check if it's PKCS#7 Signed Data (for Authenticode Scenario)
  87   //
  88   if (!PKCS7_type_is_signed (Pkcs7)) {
  89     goto _Exit;
  90   }
  91
  92   //
  93   // NOTE: OpenSSL PKCS7 Decoder didn't work for Authenticode-format signed data due to
  94   //       some authenticode-specific structure. Use opaque ASN.1 string to retrieve
  95   //       PKCS#7 ContentInfo here.
  96   //
  97   SpcIndirectDataContent = (UINT8 *)(Pkcs7->d.sign->contents->d.other->value.asn1_string->data);
  98
  99   //
 100   // Retrieve the SEQUENCE data size from ASN.1-encoded SpcIndirectDataContent.
 101   //
 102   Asn1Byte = *(SpcIndirectDataContent + 1);
 103
 104   if ((Asn1Byte & 0x80) == 0) {
 105     //
 106     // Short Form of Length Encoding
 107     //
 108     ContentSize = (UINTN) (Asn1Byte & 0x7F);
 109     //
 110     // Skip the SEQUENCE Tag;
 111     //
 112     SpcIndirectDataContent += 2;
 113   } else if ((Asn1Byte & 0x82) == 0x82) {
 114     //
 115     // Long Form of Length Encoding, only support two bytes.
 116     //
 117     ContentSize  = (UINTN) (*(SpcIndirectDataContent + 2));
 118     ContentSize = (ContentSize << 8) + (UINTN)(*(SpcIndirectDataContent + 3));
 119     //
 120     // Skip the SEQUENCE Tag;
 121     //
 122     SpcIndirectDataContent += 4;
 123   } else {
 124     goto _Exit;
 125   }
 126
 127   //
 128   // Compare the original file hash value to the digest retrieve from SpcIndirectDataContent
 129   // defined in Authenticode
 130   // NOTE: Need to double-check HashLength here!
 131   //
 132   if (CompareMem (SpcIndirectDataContent + ContentSize - HashSize, ImageHash, HashSize) != 0) {
 133     //
 134     // Un-matched PE/COFF Hash Value
 135     //
 136     goto _Exit;
 137   }
 138
 139   //
 140   // Verifies the PKCS#7 Signed Data in PE/COFF Authenticode Signature
 141   //
 142   Status = (BOOLEAN) Pkcs7Verify (OrigAuthData, DataSize, TrustedCert, CertSize, SpcIndirectDataContent, ContentSize);
 143
 144 _Exit:
 145   //
 146   // Release Resources
 147   //
 148   PKCS7_free (Pkcs7);
 149
 150   return Status;
 151 }