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 - 2015, 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 validity 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 procedure
  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  *Temp;
  76   CONST UINT8  *OrigAuthData;
  77   UINT8        *SpcIndirectDataContent;
  78   UINT8        Asn1Byte;
  79   UINTN        ContentSize;
  80   CONST UINT8  *SpcIndirectDataOid;
  81
  82   //
  83   // Check input parameters.
  84   //
  85   if ((AuthData == NULL) || (TrustedCert == NULL) || (ImageHash == NULL)) {
  86     return FALSE;
  87   }
  88
  89   if ((DataSize > INT_MAX) || (CertSize > INT_MAX) || (HashSize > INT_MAX)) {
  90     return FALSE;
  91   }
  92
  93   Status       = FALSE;
  94   Pkcs7        = NULL;
  95   OrigAuthData = AuthData;
  96
  97   //
  98   // Retrieve & Parse PKCS#7 Data (DER encoding) from Authenticode Signature
  99   //
 100   Temp  = AuthData;
 101   Pkcs7 = d2i_PKCS7 (NULL, &Temp, (int)DataSize);
 102   if (Pkcs7 == NULL) {
 103     goto _Exit;
 104   }
 105
 106   //
 107   // Check if it's PKCS#7 Signed Data (for Authenticode Scenario)
 108   //
 109   if (!PKCS7_type_is_signed (Pkcs7)) {
 110     goto _Exit;
 111   }
 112
 113   //
 114   // NOTE: OpenSSL PKCS7 Decoder didn't work for Authenticode-format signed data due to
 115   //       some authenticode-specific structure. Use opaque ASN.1 string to retrieve
 116   //       PKCS#7 ContentInfo here.
 117   //
 118   SpcIndirectDataOid = OBJ_get0_data(Pkcs7->d.sign->contents->type);
 119   if (OBJ_length(Pkcs7->d.sign->contents->type) != sizeof(mSpcIndirectOidValue) ||
 120       CompareMem (
 121         SpcIndirectDataOid,
 122         mSpcIndirectOidValue,
 123         sizeof (mSpcIndirectOidValue)
 124         ) != 0) {
 125     //
 126     // Un-matched SPC_INDIRECT_DATA_OBJID.
 127     //
 128     goto _Exit;
 129   }
 130
 131
 132   SpcIndirectDataContent = (UINT8 *)(Pkcs7->d.sign->contents->d.other->value.asn1_string->data);
 133
 134   //
 135   // Retrieve the SEQUENCE data size from ASN.1-encoded SpcIndirectDataContent.
 136   //
 137   Asn1Byte = *(SpcIndirectDataContent + 1);
 138
 139   if ((Asn1Byte & 0x80) == 0) {
 140     //
 141     // Short Form of Length Encoding (Length < 128)
 142     //
 143     ContentSize = (UINTN) (Asn1Byte & 0x7F);
 144     //
 145     // Skip the SEQUENCE Tag;
 146     //
 147     SpcIndirectDataContent += 2;
 148
 149   } else if ((Asn1Byte & 0x81) == 0x81) {
 150     //
 151     // Long Form of Length Encoding (128 <= Length < 255, Single Octet)
 152     //
 153     ContentSize = (UINTN) (*(UINT8 *)(SpcIndirectDataContent + 2));
 154     //
 155     // Skip the SEQUENCE Tag;
 156     //
 157     SpcIndirectDataContent += 3;
 158
 159   } else if ((Asn1Byte & 0x82) == 0x82) {
 160     //
 161     // Long Form of Length Encoding (Length > 255, Two Octet)
 162     //
 163     ContentSize = (UINTN) (*(UINT8 *)(SpcIndirectDataContent + 2));
 164     ContentSize = (ContentSize << 8) + (UINTN)(*(UINT8 *)(SpcIndirectDataContent + 3));
 165     //
 166     // Skip the SEQUENCE Tag;
 167     //
 168     SpcIndirectDataContent += 4;
 169
 170   } else {
 171     goto _Exit;
 172   }
 173
 174   //
 175   // Compare the original file hash value to the digest retrieve from SpcIndirectDataContent
 176   // defined in Authenticode
 177   // NOTE: Need to double-check HashLength here!
 178   //
 179   if (CompareMem (SpcIndirectDataContent + ContentSize - HashSize, ImageHash, HashSize) != 0) {
 180     //
 181     // Un-matched PE/COFF Hash Value
 182     //
 183     goto _Exit;
 184   }
 185
 186   //
 187   // Verifies the PKCS#7 Signed Data in PE/COFF Authenticode Signature
 188   //
 189   Status = (BOOLEAN) Pkcs7Verify (OrigAuthData, DataSize, TrustedCert, CertSize, SpcIndirectDataContent, ContentSize);
 190
 191 _Exit:
 192   //
 193   // Release Resources
 194   //
 195   PKCS7_free (Pkcs7);
 196
 197   return Status;
 198 }