audk/SecurityPkg/Library/AuthVariableLib/AuthServiceInternal.h

/** @file
  The internal header file includes the common header files, defines
  internal structure and functions used by AuthService module.

  Caution: This module requires additional review when modified.
  This driver will have external input - variable data. It may be input in SMM mode.
  This external input must be validated carefully to avoid security issue like
  buffer overflow, integer overflow.
  Variable attribute should also be checked to avoid authentication bypass.
     The whole SMM authentication variable design relies on the integrity of flash part and SMM.
  which is assumed to be protected by platform.  All variable code and metadata in flash/SMM Memory
  may not be modified without authorization. If platform fails to protect these resources,
  the authentication service provided in this driver will be broken, and the behavior is undefined.

Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#ifndef _AUTHSERVICE_INTERNAL_H_
#define _AUTHSERVICE_INTERNAL_H_

#include <Library/AuthVariableLib.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/BaseCryptLib.h>
#include <Library/PlatformSecureLib.h>

#include <Guid/AuthenticatedVariableFormat.h>
#include <Guid/ImageAuthentication.h>

#define TWO_BYTE_ENCODE       0x82

///
/// Struct to record signature requirement defined by UEFI spec.
/// For SigHeaderSize and SigDataSize, ((UINT32) ~0) means NO exact length requirement for this field.
///
typedef struct {
  EFI_GUID    SigType;
  // Expected SignatureHeader size in Bytes.
  UINT32      SigHeaderSize;
  // Expected SignatureData size in Bytes.
  UINT32      SigDataSize;
} EFI_SIGNATURE_ITEM;

typedef enum {
  AuthVarTypePk,
  AuthVarTypeKek,
  AuthVarTypePriv,
  AuthVarTypePayload
} AUTHVAR_TYPE;

///
///  "certdb" variable stores the signer's certificates for non PK/KEK/DB/DBX
/// variables with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS|EFI_VARIABLE_NON_VOLATILE set.
///  "certdbv" variable stores the signer's certificates for non PK/KEK/DB/DBX
/// variables with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
///
/// GUID: gEfiCertDbGuid
///
/// We need maintain atomicity.
///
/// Format:
/// +----------------------------+
/// | UINT32                     | <-- CertDbListSize, including this UINT32
/// +----------------------------+
/// | AUTH_CERT_DB_DATA          | <-- First CERT
/// +----------------------------+
/// | ........                   |
/// +----------------------------+
/// | AUTH_CERT_DB_DATA          | <-- Last CERT
/// +----------------------------+
///
#define EFI_CERT_DB_NAME                 L"certdb"
#define EFI_CERT_DB_VOLATILE_NAME        L"certdbv"

#pragma pack(1)
typedef struct {
  EFI_GUID    VendorGuid;
  UINT32      CertNodeSize;
  UINT32      NameSize;
  UINT32      CertDataSize;
  /// CHAR16  VariableName[NameSize];
  /// UINT8   CertData[CertDataSize];
} AUTH_CERT_DB_DATA;
#pragma pack()

extern UINT8    *mCertDbStore;
extern UINT32   mMaxCertDbSize;
extern UINT32   mPlatformMode;
extern UINT8    mVendorKeyState;

extern VOID     *mHashCtx;

extern AUTH_VAR_LIB_CONTEXT_IN *mAuthVarLibContextIn;


/**
  Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set

  Caution: This function may receive untrusted input.
  This function may be invoked in SMM mode, and datasize and data are external input.
  This function will do basic validation, before parse the data.
  This function will parse the authentication carefully to avoid security issues, like
  buffer overflow, integer overflow.

  @param[in]  VariableName                Name of Variable to be found.
  @param[in]  VendorGuid                  Variable vendor GUID.
  @param[in]  Data                        Data pointer.
  @param[in]  DataSize                    Size of Data found. If size is less than the
                                          data, this value contains the required size.
  @param[in]  Attributes                  Attribute value of the variable.
  @param[in]  AuthVarType                 Verify against PK, KEK database, private database or certificate in data payload.
  @param[out] VarDel                      Delete the variable or not.

  @retval EFI_INVALID_PARAMETER           Invalid parameter.
  @retval EFI_SECURITY_VIOLATION          The variable does NOT pass the validation
                                          check carried out by the firmware.
  @retval EFI_OUT_OF_RESOURCES            Failed to process variable due to lack
                                          of resources.
  @retval EFI_SUCCESS                     Variable pass validation successfully.

**/
EFI_STATUS
VerifyTimeBasedPayloadAndUpdate (
  IN     CHAR16                             *VariableName,
  IN     EFI_GUID                           *VendorGuid,
  IN     VOID                               *Data,
  IN     UINTN                              DataSize,
  IN     UINT32                             Attributes,
  IN     AUTHVAR_TYPE                       AuthVarType,
  OUT    BOOLEAN                            *VarDel
  );

/**
  Delete matching signer's certificates when deleting common authenticated
  variable by corresponding VariableName and VendorGuid from "certdb" or
  "certdbv" according to authenticated variable attributes.

  @param[in]  VariableName   Name of authenticated Variable.
  @param[in]  VendorGuid     Vendor GUID of authenticated Variable.
  @param[in]  Attributes        Attributes of authenticated variable.

  @retval  EFI_INVALID_PARAMETER Any input parameter is invalid.
  @retval  EFI_NOT_FOUND         Fail to find "certdb"/"certdbv" or matching certs.
  @retval  EFI_OUT_OF_RESOURCES  The operation is failed due to lack of resources.
  @retval  EFI_SUCCESS           The operation is completed successfully.

**/
EFI_STATUS
DeleteCertsFromDb (
  IN     CHAR16           *VariableName,
  IN     EFI_GUID         *VendorGuid,
  IN     UINT32           Attributes
  );

/**
  Clean up signer's certificates for common authenticated variable
  by corresponding VariableName and VendorGuid from "certdb".
  Sytem may break down during Timebased Variable update & certdb update,
  make them inconsistent,  this function is called in AuthVariable Init to ensure
  consistency

  @retval  EFI_NOT_FOUND         Fail to find matching certs.
  @retval  EFI_SUCCESS           Find matching certs and output parameters.

**/
EFI_STATUS
CleanCertsFromDb (
  VOID
  );

/**
  Filter out the duplicated EFI_SIGNATURE_DATA from the new data by comparing to the original data.

  @param[in]        Data          Pointer to original EFI_SIGNATURE_LIST.
  @param[in]        DataSize      Size of Data buffer.
  @param[in, out]   NewData       Pointer to new EFI_SIGNATURE_LIST.
  @param[in, out]   NewDataSize   Size of NewData buffer.

**/
EFI_STATUS
FilterSignatureList (
  IN     VOID       *Data,
  IN     UINTN      DataSize,
  IN OUT VOID       *NewData,
  IN OUT UINTN      *NewDataSize
  );

/**
  Process variable with platform key for verification.

  Caution: This function may receive untrusted input.
  This function may be invoked in SMM mode, and datasize and data are external input.
  This function will do basic validation, before parse the data.
  This function will parse the authentication carefully to avoid security issues, like
  buffer overflow, integer overflow.
  This function will check attribute carefully to avoid authentication bypass.

  @param[in]  VariableName                Name of Variable to be found.
  @param[in]  VendorGuid                  Variable vendor GUID.
  @param[in]  Data                        Data pointer.
  @param[in]  DataSize                    Size of Data found. If size is less than the
                                          data, this value contains the required size.
  @param[in]  Attributes                  Attribute value of the variable
  @param[in]  IsPk                        Indicate whether it is to process pk.

  @return EFI_INVALID_PARAMETER           Invalid parameter.
  @return EFI_SECURITY_VIOLATION          The variable does NOT pass the validation.
                                          check carried out by the firmware.
  @return EFI_SUCCESS                     Variable passed validation successfully.

**/
EFI_STATUS
ProcessVarWithPk (
  IN  CHAR16                    *VariableName,
  IN  EFI_GUID                  *VendorGuid,
  IN  VOID                      *Data,
  IN  UINTN                     DataSize,
  IN  UINT32                    Attributes OPTIONAL,
  IN  BOOLEAN                   IsPk
  );

/**
  Process variable with key exchange key for verification.

  Caution: This function may receive untrusted input.
  This function may be invoked in SMM mode, and datasize and data are external input.
  This function will do basic validation, before parse the data.
  This function will parse the authentication carefully to avoid security issues, like
  buffer overflow, integer overflow.
  This function will check attribute carefully to avoid authentication bypass.

  @param[in]  VariableName                Name of Variable to be found.
  @param[in]  VendorGuid                  Variable vendor GUID.
  @param[in]  Data                        Data pointer.
  @param[in]  DataSize                    Size of Data found. If size is less than the
                                          data, this value contains the required size.
  @param[in]  Attributes                  Attribute value of the variable.

  @return EFI_INVALID_PARAMETER           Invalid parameter.
  @return EFI_SECURITY_VIOLATION          The variable does NOT pass the validation
                                          check carried out by the firmware.
  @return EFI_SUCCESS                     Variable pass validation successfully.

**/
EFI_STATUS
ProcessVarWithKek (
  IN  CHAR16                               *VariableName,
  IN  EFI_GUID                             *VendorGuid,
  IN  VOID                                 *Data,
  IN  UINTN                                DataSize,
  IN  UINT32                               Attributes OPTIONAL
  );

/**
  Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set

  Caution: This function may receive untrusted input.
  This function may be invoked in SMM mode, and datasize and data are external input.
  This function will do basic validation, before parse the data.
  This function will parse the authentication carefully to avoid security issues, like
  buffer overflow, integer overflow.
  This function will check attribute carefully to avoid authentication bypass.

  @param[in]  VariableName                Name of the variable.
  @param[in]  VendorGuid                  Variable vendor GUID.
  @param[in]  Data                        Data pointer.
  @param[in]  DataSize                    Size of Data.
  @param[in]  Attributes                  Attribute value of the variable.

  @return EFI_INVALID_PARAMETER           Invalid parameter.
  @return EFI_WRITE_PROTECTED             Variable is write-protected and needs authentication with
                                          EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS or EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set.
  @return EFI_OUT_OF_RESOURCES            The Database to save the public key is full.
  @return EFI_SECURITY_VIOLATION          The variable is with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
                                          set, but the AuthInfo does NOT pass the validation
                                          check carried out by the firmware.
  @return EFI_SUCCESS                     Variable is not write-protected or pass validation successfully.

**/
EFI_STATUS
ProcessVariable (
  IN     CHAR16                             *VariableName,
  IN     EFI_GUID                           *VendorGuid,
  IN     VOID                               *Data,
  IN     UINTN                              DataSize,
  IN     UINT32                             Attributes
  );

/**
  Finds variable in storage blocks of volatile and non-volatile storage areas.

  This code finds variable in storage blocks of volatile and non-volatile storage areas.
  If VariableName is an empty string, then we just return the first
  qualified variable without comparing VariableName and VendorGuid.

  @param[in]  VariableName          Name of the variable to be found.
  @param[in]  VendorGuid            Variable vendor GUID to be found.
  @param[out] Data                  Pointer to data address.
  @param[out] DataSize              Pointer to data size.

  @retval EFI_INVALID_PARAMETER     If VariableName is not an empty string,
                                    while VendorGuid is NULL.
  @retval EFI_SUCCESS               Variable successfully found.
  @retval EFI_NOT_FOUND             Variable not found

**/
EFI_STATUS
AuthServiceInternalFindVariable (
  IN  CHAR16        *VariableName,
  IN  EFI_GUID      *VendorGuid,
  OUT VOID          **Data,
  OUT UINTN         *DataSize
  );

/**
  Update the variable region with Variable information.

  @param[in] VariableName           Name of variable.
  @param[in] VendorGuid             Guid of variable.
  @param[in] Data                   Data pointer.
  @param[in] DataSize               Size of Data.
  @param[in] Attributes             Attribute value of the variable.

  @retval EFI_SUCCESS               The update operation is success.
  @retval EFI_INVALID_PARAMETER     Invalid parameter.
  @retval EFI_WRITE_PROTECTED       Variable is write-protected.
  @retval EFI_OUT_OF_RESOURCES      There is not enough resource.

**/
EFI_STATUS
AuthServiceInternalUpdateVariable (
  IN CHAR16         *VariableName,
  IN EFI_GUID       *VendorGuid,
  IN VOID           *Data,
  IN UINTN          DataSize,
  IN UINT32         Attributes
  );

/**
  Update the variable region with Variable information.

  @param[in] VariableName           Name of variable.
  @param[in] VendorGuid             Guid of variable.
  @param[in] Data                   Data pointer.
  @param[in] DataSize               Size of Data.
  @param[in] Attributes             Attribute value of the variable.
  @param[in] TimeStamp              Value of associated TimeStamp.

  @retval EFI_SUCCESS               The update operation is success.
  @retval EFI_INVALID_PARAMETER     Invalid parameter.
  @retval EFI_WRITE_PROTECTED       Variable is write-protected.
  @retval EFI_OUT_OF_RESOURCES      There is not enough resource.

**/
EFI_STATUS
AuthServiceInternalUpdateVariableWithTimeStamp (
  IN CHAR16         *VariableName,
  IN EFI_GUID       *VendorGuid,
  IN VOID           *Data,
  IN UINTN          DataSize,
  IN UINT32         Attributes,
  IN EFI_TIME       *TimeStamp
  );

#endif