CryptoPkg/Library/BaseCryptLibNull/Pk/CryptPkcs7VerifyEkuNull.c

   1 /** @file
   2   PKCS7 Verify Null implementation.
   3
   4   Copyright (C) Microsoft Corporation. All Rights Reserved.
   5   Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10
  11 #include "InternalCryptLib.h"
  12
  13 /**
  14   This function will return the leaf signer certificate in a chain.  This is
  15   required because certificate chains are not guaranteed to have the
  16   certificates in the order that they were issued.
  17
  18   A typical certificate chain looks like this:
  19
  20
  21                  ----------------------------
  22                 |            Root            |
  23                  ----------------------------
  24                                ^
  25                                |
  26                  ----------------------------
  27                 |          Policy CA         | <-- Typical Trust Anchor.
  28                  ----------------------------
  29                                ^
  30                                |
  31                  ----------------------------
  32                 |         Issuing CA         |
  33                  ----------------------------
  34                                ^
  35                                |
  36                  -----------------------------
  37                 /  End-Entity (leaf) signer  / <-- Bottom certificate.
  38                 -----------------------------  EKU: "1.3.6.1.4.1.311.76.9.21.1"
  39                                                     (Firmware Signing)
  40
  41
  42   @param[in]   CertChain            Certificate chain.
  43
  44   @param[out]  SignerCert           Last certificate in the chain.  For PKCS7 signatures,
  45                                     this will be the end-entity (leaf) signer cert.
  46
  47   @retval EFI_SUCCESS               The required EKUs were found in the signature.
  48   @retval EFI_INVALID_PARAMETER     A parameter was invalid.
  49   @retval EFI_NOT_FOUND             The number of signers found was not 1.
  50
  51 **/
  52 EFI_STATUS
  53 GetSignerCertificate (
  54   IN CONST VOID  *CertChain,
  55   OUT VOID       **SignerCert
  56   )
  57 {
  58   ASSERT (FALSE);
  59   return EFI_NOT_READY;
  60 }
  61
  62 /**
  63   Determines if the specified EKU represented in ASN1 form is present
  64   in a given certificate.
  65
  66   @param[in]  Cert                  The certificate to check.
  67
  68   @param[in]  Asn1ToFind            The EKU to look for.
  69
  70   @retval EFI_SUCCESS               We successfully identified the signing type.
  71   @retval EFI_INVALID_PARAMETER     A parameter was invalid.
  72   @retval EFI_NOT_FOUND             One or more EKU's were not found in the signature.
  73
  74 **/
  75 EFI_STATUS
  76 IsEkuInCertificate (
  77   IN CONST VOID  *Cert,
  78   IN VOID        *Asn1ToFind
  79   )
  80 {
  81   ASSERT (FALSE);
  82   return EFI_NOT_READY;
  83 }
  84
  85 /**
  86   Determines if the specified EKUs are present in a signing certificate.
  87
  88   @param[in]  SignerCert            The certificate to check.
  89   @param[in]  RequiredEKUs          The EKUs to look for.
  90   @param[in]  RequiredEKUsSize      The number of EKUs
  91   @param[in]  RequireAllPresent     If TRUE, then all the specified EKUs
  92                                     must be present in the certificate.
  93
  94   @retval EFI_SUCCESS               We successfully identified the signing type.
  95   @retval EFI_INVALID_PARAMETER     A parameter was invalid.
  96   @retval EFI_NOT_FOUND             One or more EKU's were not found in the signature.
  97 **/
  98 EFI_STATUS
  99 CheckEKUs (
 100   IN CONST VOID    *SignerCert,
 101   IN CONST CHAR8   *RequiredEKUs[],
 102   IN CONST UINT32  RequiredEKUsSize,
 103   IN BOOLEAN       RequireAllPresent
 104   )
 105 {
 106   ASSERT (FALSE);
 107   return EFI_NOT_READY;
 108 }
 109
 110 /**
 111   This function receives a PKCS#7 formatted signature blob,
 112   looks for the EKU SEQUENCE blob, and if found then looks
 113   for all the required EKUs. This function was created so that
 114   the Surface team can cut down on the number of Certificate
 115   Authorities (CA's) by checking EKU's on leaf signers for
 116   a specific product. This prevents one product's certificate
 117   from signing another product's firmware or unlock blobs.
 118
 119   Note that this function does not validate the certificate chain.
 120   That needs to be done before using this function.
 121
 122   @param[in]  Pkcs7Signature       The PKCS#7 signed information content block. An array
 123                                    containing the content block with both the signature,
 124                                    the signer's certificate, and any necessary intermediate
 125                                    certificates.
 126   @param[in]  Pkcs7SignatureSize   Number of bytes in Pkcs7Signature.
 127   @param[in]  RequiredEKUs         Array of null-terminated strings listing OIDs of
 128                                    required EKUs that must be present in the signature.
 129   @param[in]  RequiredEKUsSize     Number of elements in the RequiredEKUs string array.
 130   @param[in]  RequireAllPresent    If this is TRUE, then all of the specified EKU's
 131                                    must be present in the leaf signer.  If it is
 132                                    FALSE, then we will succeed if we find any
 133                                    of the specified EKU's.
 134
 135   @retval EFI_SUCCESS              The required EKUs were found in the signature.
 136   @retval EFI_INVALID_PARAMETER    A parameter was invalid.
 137   @retval EFI_NOT_FOUND            One or more EKU's were not found in the signature.
 138
 139 **/
 140 EFI_STATUS
 141 EFIAPI
 142 VerifyEKUsInPkcs7Signature (
 143   IN CONST UINT8   *Pkcs7Signature,
 144   IN CONST UINT32  SignatureSize,
 145   IN CONST CHAR8   *RequiredEKUs[],
 146   IN CONST UINT32  RequiredEKUsSize,
 147   IN BOOLEAN       RequireAllPresent
 148   )
 149 {
 150   ASSERT (FALSE);
 151   return EFI_NOT_READY;
 152 }