CryptoPkg/Library/BaseCryptLib/Pk/CryptAuthenticode.c

   1 /** @file
   2   Authenticode Portable Executable Signature Verification over OpenSSL.
   3
   4   Caution: This module requires additional review when modified.
   5   This library will have external input - signature (e.g. PE/COFF Authenticode).
   6   This external input must be validated carefully to avoid security issue like
   7   buffer overflow, integer overflow.
   8
   9   AuthenticodeVerify() will get PE/COFF Authenticode and will do basic check for
  10   data structure.
  11
  12 Copyright (c) 2011 - 2012, Intel Corporation. All rights reserved.<BR>
  13 This program and the accompanying materials
  14 are licensed and made available under the terms and conditions of the BSD License
  15 which accompanies this distribution.  The full text of the license may be found at
  16 http://opensource.org/licenses/bsd-license.php
  17
  18 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  19 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  20
  21 **/
  22
  23 #include "InternalCryptLib.h"
  24
  25 #include <openssl/objects.h>
  26 #include <openssl/x509.h>
  27 #include <openssl/pkcs7.h>
  28
  29 //
  30 // OID ASN.1 Value for SPC_INDIRECT_DATA_OBJID
  31 //
  32 UINT8 mSpcIndirectOidValue[] = {
  33   0x2B, 0x06, 0x01, 0x04, 0x01, 0x82, 0x37, 0x02, 0x01, 0x04
  34   };
  35
  36 /**
  37   Verifies the validility of a PE/COFF Authenticode Signature as described in "Windows
  38   Authenticode Portable Executable Signature Format".
  39
  40   If AuthData is NULL, then return FALSE.
  41   If ImageHash is NULL, then return FALSE.
  42
  43   Caution: This function may receive untrusted input.
  44   PE/COFF Authenticode is external input, so this function will do basic check for
  45   Authenticode data structure.
  46
  47   @param[in]  AuthData     Pointer to the Authenticode Signature retrieved from signed
  48                            PE/COFF image to be verified.
  49   @param[in]  DataSize     Size of the Authenticode Signature in bytes.
  50   @param[in]  TrustedCert  Pointer to a trusted/root certificate encoded in DER, which
  51                            is used for certificate chain verification.
  52   @param[in]  CertSize     Size of the trusted certificate in bytes.
  53   @param[in]  ImageHash    Pointer to the original image file hash value. The procudure
  54                            for calculating the image hash value is described in Authenticode
  55                            specification.
  56   @param[in]  HashSize     Size of Image hash value in bytes.
  57
  58   @retval  TRUE   The specified Authenticode Signature is valid.
  59   @retval  FALSE  Invalid Authenticode Signature.
  60
  61 **/
  62 BOOLEAN
  63 EFIAPI
  64 AuthenticodeVerify (
  65   IN  CONST UINT8  *AuthData,
  66   IN  UINTN        DataSize,
  67   IN  CONST UINT8  *TrustedCert,
  68   IN  UINTN        CertSize,
  69   IN  CONST UINT8  *ImageHash,
  70   IN  UINTN        HashSize
  71   )
  72 {
  73   BOOLEAN      Status;
  74   PKCS7        *Pkcs7;
  75   CONST UINT8  *OrigAuthData;
  76   UINT8        *SpcIndirectDataContent;
  77   UINT8        Asn1Byte;
  78   UINTN        ContentSize;
  79   UINT8        *SpcIndirectDataOid;
  80
  81   //
  82   // Check input parameters.
  83   //
  84   if ((AuthData == NULL) || (TrustedCert == NULL) || (ImageHash == NULL)) {
  85     return FALSE;
  86   }
  87
  88   if ((DataSize > INT_MAX) || (CertSize > INT_MAX) || (HashSize > INT_MAX)) {
  89     return FALSE;
  90   }
  91
  92   Status       = FALSE;
  93   Pkcs7        = NULL;
  94   OrigAuthData = AuthData;
  95
  96   //
  97   // Retrieve & Parse PKCS#7 Data (DER encoding) from Authenticode Signature
  98   //
  99   Pkcs7 = d2i_PKCS7 (NULL, &AuthData, (int)DataSize);
 100   if (Pkcs7 == NULL) {
 101     goto _Exit;
 102   }
 103
 104   //
 105   // Check if it's PKCS#7 Signed Data (for Authenticode Scenario)
 106   //
 107   if (!PKCS7_type_is_signed (Pkcs7)) {
 108     goto _Exit;
 109   }
 110
 111   //
 112   // NOTE: OpenSSL PKCS7 Decoder didn't work for Authenticode-format signed data due to
 113   //       some authenticode-specific structure. Use opaque ASN.1 string to retrieve
 114   //       PKCS#7 ContentInfo here.
 115   //
 116   SpcIndirectDataOid = (UINT8 *)(Pkcs7->d.sign->contents->type->data);
 117   if (CompareMem (
 118         SpcIndirectDataOid,
 119         mSpcIndirectOidValue,
 120         sizeof (mSpcIndirectOidValue)
 121         ) != 0) {
 122     //
 123     // Un-matched SPC_INDIRECT_DATA_OBJID.
 124     //
 125     goto _Exit;
 126   }
 127
 128
 129   SpcIndirectDataContent = (UINT8 *)(Pkcs7->d.sign->contents->d.other->value.asn1_string->data);
 130
 131   //
 132   // Retrieve the SEQUENCE data size from ASN.1-encoded SpcIndirectDataContent.
 133   //
 134   Asn1Byte = *(SpcIndirectDataContent + 1);
 135
 136   if ((Asn1Byte & 0x80) == 0) {
 137     //
 138     // Short Form of Length Encoding
 139     //
 140     ContentSize = (UINTN) (Asn1Byte & 0x7F);
 141     //
 142     // Skip the SEQUENCE Tag;
 143     //
 144     SpcIndirectDataContent += 2;
 145   } else if ((Asn1Byte & 0x82) == 0x82) {
 146     //
 147     // Long Form of Length Encoding, only support two bytes.
 148     //
 149     ContentSize = (UINTN) (*(UINT8 *)(SpcIndirectDataContent + 2));
 150     ContentSize = (ContentSize << 8) + (UINTN)(*(UINT8 *)(SpcIndirectDataContent + 3));
 151     //
 152     // Skip the SEQUENCE Tag;
 153     //
 154     SpcIndirectDataContent += 4;
 155   } else {
 156     goto _Exit;
 157   }
 158
 159   //
 160   // Compare the original file hash value to the digest retrieve from SpcIndirectDataContent
 161   // defined in Authenticode
 162   // NOTE: Need to double-check HashLength here!
 163   //
 164   if (CompareMem (SpcIndirectDataContent + ContentSize - HashSize, ImageHash, HashSize) != 0) {
 165     //
 166     // Un-matched PE/COFF Hash Value
 167     //
 168     goto _Exit;
 169   }
 170
 171   //
 172   // Verifies the PKCS#7 Signed Data in PE/COFF Authenticode Signature
 173   //
 174   Status = (BOOLEAN) Pkcs7Verify (OrigAuthData, DataSize, TrustedCert, CertSize, SpcIndirectDataContent, ContentSize);
 175
 176 _Exit:
 177   //
 178   // Release Resources
 179   //
 180   PKCS7_free (Pkcs7);
 181
 182   return Status;
 183 }