CryptoPkg/BaseCryptLib: fix NULL dereference (CVE-2019-14584)

[mirror_edk2.git] / CryptoPkg / Library / BaseCryptLib / Pk / CryptAuthenticode.c

/** @file\r
  Authenticode Portable Executable Signature Verification over OpenSSL.\r
\r
  Caution: This module requires additional review when modified.\r
  This library will have external input - signature (e.g. PE/COFF Authenticode).\r
  This external input must be validated carefully to avoid security issue like\r
  buffer overflow, integer overflow.\r
\r
  AuthenticodeVerify() will get PE/COFF Authenticode and will do basic check for\r
  data structure.\r
\r
Copyright (c) 2011 - 2020, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "InternalCryptLib.h"\r
\r
#include <openssl/objects.h>\r
#include <openssl/x509.h>\r
#include <openssl/pkcs7.h>\r
\r
//\r
// OID ASN.1 Value for SPC_INDIRECT_DATA_OBJID\r
//\r
UINT8 mSpcIndirectOidValue[] = {\r
  0x2B, 0x06, 0x01, 0x04, 0x01, 0x82, 0x37, 0x02, 0x01, 0x04\r
  };\r
\r
/**\r
  Verifies the validity of a PE/COFF Authenticode Signature as described in "Windows\r
  Authenticode Portable Executable Signature Format".\r
\r
  If AuthData is NULL, then return FALSE.\r
  If ImageHash is NULL, then return FALSE.\r
\r
  Caution: This function may receive untrusted input.\r
  PE/COFF Authenticode is external input, so this function will do basic check for\r
  Authenticode data structure.\r
\r
  @param[in]  AuthData     Pointer to the Authenticode Signature retrieved from signed\r
                           PE/COFF image to be verified.\r
  @param[in]  DataSize     Size of the Authenticode Signature in bytes.\r
  @param[in]  TrustedCert  Pointer to a trusted/root certificate encoded in DER, which\r
                           is used for certificate chain verification.\r
  @param[in]  CertSize     Size of the trusted certificate in bytes.\r
  @param[in]  ImageHash    Pointer to the original image file hash value. The procedure\r
                           for calculating the image hash value is described in Authenticode\r
                           specification.\r
  @param[in]  HashSize     Size of Image hash value in bytes.\r
\r
  @retval  TRUE   The specified Authenticode Signature is valid.\r
  @retval  FALSE  Invalid Authenticode Signature.\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
AuthenticodeVerify (\r
  IN  CONST UINT8  *AuthData,\r
  IN  UINTN        DataSize,\r
  IN  CONST UINT8  *TrustedCert,\r
  IN  UINTN        CertSize,\r
  IN  CONST UINT8  *ImageHash,\r
  IN  UINTN        HashSize\r
  )\r
{\r
  BOOLEAN      Status;\r
  PKCS7        *Pkcs7;\r
  CONST UINT8  *Temp;\r
  CONST UINT8  *OrigAuthData;\r
  UINT8        *SpcIndirectDataContent;\r
  UINT8        Asn1Byte;\r
  UINTN        ContentSize;\r
  CONST UINT8  *SpcIndirectDataOid;\r
\r
  //\r
  // Check input parameters.\r
  //\r
  if ((AuthData == NULL) || (TrustedCert == NULL) || (ImageHash == NULL)) {\r
    return FALSE;\r
  }\r
\r
  if ((DataSize > INT_MAX) || (CertSize > INT_MAX) || (HashSize > INT_MAX)) {\r
    return FALSE;\r
  }\r
\r
  Status       = FALSE;\r
  Pkcs7        = NULL;\r
  OrigAuthData = AuthData;\r
\r
  //\r
  // Retrieve & Parse PKCS#7 Data (DER encoding) from Authenticode Signature\r
  //\r
  Temp  = AuthData;\r
  Pkcs7 = d2i_PKCS7 (NULL, &Temp, (int)DataSize);\r
  if (Pkcs7 == NULL) {\r
    goto _Exit;\r
  }\r
\r
  //\r
  // Check if it's PKCS#7 Signed Data (for Authenticode Scenario)\r
  //\r
  if (!PKCS7_type_is_signed (Pkcs7) || PKCS7_get_detached (Pkcs7)) {\r
    goto _Exit;\r
  }\r
\r
  //\r
  // NOTE: OpenSSL PKCS7 Decoder didn't work for Authenticode-format signed data due to\r
  //       some authenticode-specific structure. Use opaque ASN.1 string to retrieve\r
  //       PKCS#7 ContentInfo here.\r
  //\r
  SpcIndirectDataOid = OBJ_get0_data(Pkcs7->d.sign->contents->type);\r
  if (OBJ_length(Pkcs7->d.sign->contents->type) != sizeof(mSpcIndirectOidValue) ||\r
      CompareMem (\r
        SpcIndirectDataOid,\r
        mSpcIndirectOidValue,\r
        sizeof (mSpcIndirectOidValue)\r
        ) != 0) {\r
    //\r
    // Un-matched SPC_INDIRECT_DATA_OBJID.\r
    //\r
    goto _Exit;\r
  }\r
\r
\r
  SpcIndirectDataContent = (UINT8 *)(Pkcs7->d.sign->contents->d.other->value.asn1_string->data);\r
\r
  //\r
  // Retrieve the SEQUENCE data size from ASN.1-encoded SpcIndirectDataContent.\r
  //\r
  Asn1Byte = *(SpcIndirectDataContent + 1);\r
\r
  if ((Asn1Byte & 0x80) == 0) {\r
    //\r
    // Short Form of Length Encoding (Length < 128)\r
    //\r
    ContentSize = (UINTN) (Asn1Byte & 0x7F);\r
    //\r
    // Skip the SEQUENCE Tag;\r
    //\r
    SpcIndirectDataContent += 2;\r
\r
  } else if ((Asn1Byte & 0x81) == 0x81) {\r
    //\r
    // Long Form of Length Encoding (128 <= Length < 255, Single Octet)\r
    //\r
    ContentSize = (UINTN) (*(UINT8 *)(SpcIndirectDataContent + 2));\r
    //\r
    // Skip the SEQUENCE Tag;\r
    //\r
    SpcIndirectDataContent += 3;\r
\r
  } else if ((Asn1Byte & 0x82) == 0x82) {\r
    //\r
    // Long Form of Length Encoding (Length > 255, Two Octet)\r
    //\r
    ContentSize = (UINTN) (*(UINT8 *)(SpcIndirectDataContent + 2));\r
    ContentSize = (ContentSize << 8) + (UINTN)(*(UINT8 *)(SpcIndirectDataContent + 3));\r
    //\r
    // Skip the SEQUENCE Tag;\r
    //\r
    SpcIndirectDataContent += 4;\r
\r
  } else {\r
    goto _Exit;\r
  }\r
\r
  //\r
  // Compare the original file hash value to the digest retrieve from SpcIndirectDataContent\r
  // defined in Authenticode\r
  // NOTE: Need to double-check HashLength here!\r
  //\r
  if (CompareMem (SpcIndirectDataContent + ContentSize - HashSize, ImageHash, HashSize) != 0) {\r
    //\r
    // Un-matched PE/COFF Hash Value\r
    //\r
    goto _Exit;\r
  }\r
\r
  //\r
  // Verifies the PKCS#7 Signed Data in PE/COFF Authenticode Signature\r
  //\r
  Status = (BOOLEAN) Pkcs7Verify (OrigAuthData, DataSize, TrustedCert, CertSize, SpcIndirectDataContent, ContentSize);\r
\r
_Exit:\r
  //\r
  // Release Resources\r
  //\r
  PKCS7_free (Pkcs7);\r
\r
  return Status;\r
}\r