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SecurityPkg: AuthVariableLib: Customized SecureBoot Mode transition. 

Implement Customized SecureBoot Mode transition logic according to Mantis 1263, including AuditMode/DeployedMode/PK update management.
  Also implement image verification logic in AuditMode. Image Certificate & Hash are recorded to EFI Image Execution Table.
  https://mantis.uefi.org/mantis/view.php?id=1263

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chao Zhang <chao.b.zhang@intel.com>
Reviewed-by: Zeng Star <star.zeng@intel.com>
Reviewed-by: Long Qin <qin.long@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19133 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Chao Zhang 2015-12-07 06:20:02 +00:00 committed by czhang46
parent af9af05bec
commit 4fc08e8d68
5 changed files with 1913 additions and 269 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1286
SecurityPkg/Library/AuthVariableLib/AuthService.c
View File

File diff suppressed because it is too large Load Diff

93
SecurityPkg/Library/AuthVariableLib/AuthServiceInternal.h
View File

@ -117,6 +117,54 @@ typedef struct {
} AUTH_CERT_DB_DATA;
#pragma pack()
///
/// "SecureBootMode" variable stores current secure boot mode.
/// The value type is SECURE_BOOT_MODE_TYPE.
///
#define EDKII_SECURE_BOOT_MODE_NAME L"SecureBootMode"
typedef enum {
SecureBootModeTypeUserMode,
SecureBootModeTypeSetupMode,
SecureBootModeTypeAuditMode,
SecureBootModeTypeDeployedMode,
SecureBootModeTypeMax
} SECURE_BOOT_MODE_TYPE;
//
// Record status info of Customized Secure Boot Mode.
//
typedef struct {
///
/// AuditMode variable value
///
UINT8 AuditMode;
///
/// AuditMode variable RW
///
BOOLEAN IsAuditModeRO;
///
/// DeployedMode variable value
///
UINT8 DeployedMode;
///
/// AuditMode variable RW
///
BOOLEAN IsDeployedModeRO;
///
/// SetupMode variable value
///
UINT8 SetupMode;
///
/// SetupMode is always RO. Skip IsSetupModeRO;
///
///
/// SecureBoot variable value
///
UINT8 SecureBoot;
} SECURE_BOOT_MODE;
extern UINT8 *mPubKeyStore;
extern UINT32 mPubKeyNumber;
extern UINT32 mMaxKeyNumber;
@ -130,6 +178,18 @@ extern VOID *mHashCtx;
extern AUTH_VAR_LIB_CONTEXT_IN *mAuthVarLibContextIn;
/**
Initialize Secure Boot variables.
@retval EFI_SUCCESS The initialization operation is successful.
@retval EFI_OUT_OF_RESOURCES There is not enough resource.
**/
EFI_STATUS
InitSecureBootVariables (
VOID
);
/**
Process variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
@ -219,6 +279,39 @@ FilterSignatureList (
IN OUT UINTN *NewDataSize
);
/**
Process Secure Boot Mode variable.
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_WRITE_PROTECTED Variable is Read-Only.
@return EFI_SUCCESS Variable passed validation successfully.
**/
EFI_STATUS
ProcessSecureBootModeVar (
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid,
IN VOID *Data,
IN UINTN DataSize,
IN UINT32 Attributes OPTIONAL
);
/**
Process variable with platform key for verification.

111
SecurityPkg/Library/AuthVariableLib/AuthVariableLib.c
View File

@ -33,7 +33,6 @@ UINT32 mMaxKeyNumber;
UINT32 mMaxKeyDbSize;
UINT8 *mCertDbStore;
UINT32 mMaxCertDbSize;
UINT32 mPlatformMode;
UINT8 mVendorKeyState;
EFI_GUID mSignatureSupport[] = {EFI_CERT_SHA1_GUID, EFI_CERT_SHA256_GUID, EFI_CERT_RSA2048_GUID, EFI_CERT_X509_GUID};
@ -99,6 +98,17 @@ VARIABLE_ENTRY_PROPERTY mAuthVarEntry[] = {
MAX_UINTN
}
},
{
&gEdkiiSecureBootModeGuid,
L"SecureBootMode",
{
VAR_CHECK_VARIABLE_PROPERTY_REVISION,
VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY,
VARIABLE_ATTRIBUTE_NV_BS_RT,
sizeof (UINT8),
sizeof (UINT8)
}
}
};
VOID **mAuthVarAddressPointer[10];
@ -132,8 +142,6 @@ AuthVariableLibInitialize (
UINT8 *Data;
UINTN DataSize;
UINTN CtxSize;
UINT8 SecureBootMode;
UINT8 SecureBootEnable;
UINT8 CustomMode;
UINT32 ListSize;
@ -208,31 +216,11 @@ AuthVariableLibInitialize (
mPubKeyNumber = (UINT32) (DataSize / sizeof (AUTHVAR_KEY_DB_DATA));
}
Status = AuthServiceInternalFindVariable (EFI_PLATFORM_KEY_NAME, &gEfiGlobalVariableGuid, (VOID **) &Data, &DataSize);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_INFO, "Variable %s does not exist.\n", EFI_PLATFORM_KEY_NAME));
} else {
DEBUG ((EFI_D_INFO, "Variable %s exists.\n", EFI_PLATFORM_KEY_NAME));
}
//
// Init Secure Boot variables
//
Status = InitSecureBootVariables ();
//
// Create "SetupMode" variable with BS+RT attribute set.
//
if (EFI_ERROR (Status)) {
mPlatformMode = SETUP_MODE;
} else {
mPlatformMode = USER_MODE;
}
Status = AuthServiceInternalUpdateVariable (
EFI_SETUP_MODE_NAME,
&gEfiGlobalVariableGuid,
&mPlatformMode,
sizeof(UINT8),
EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS
);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Create "SignatureSupport" variable with BS+RT attribute set.
@ -248,69 +236,6 @@ AuthVariableLibInitialize (
return Status;
}
//
// If "SecureBootEnable" variable exists, then update "SecureBoot" variable.
// If "SecureBootEnable" variable is SECURE_BOOT_ENABLE and in USER_MODE, Set "SecureBoot" variable to SECURE_BOOT_MODE_ENABLE.
// If "SecureBootEnable" variable is SECURE_BOOT_DISABLE, Set "SecureBoot" variable to SECURE_BOOT_MODE_DISABLE.
//
SecureBootEnable = SECURE_BOOT_DISABLE;
Status = AuthServiceInternalFindVariable (EFI_SECURE_BOOT_ENABLE_NAME, &gEfiSecureBootEnableDisableGuid, (VOID **) &Data, &DataSize);
if (!EFI_ERROR (Status)) {
if (mPlatformMode == SETUP_MODE){
//
// PK is cleared in runtime. "SecureBootMode" is not updated before reboot
// Delete "SecureBootMode" in SetupMode
//
Status = AuthServiceInternalUpdateVariable (
EFI_SECURE_BOOT_ENABLE_NAME,
&gEfiSecureBootEnableDisableGuid,
&SecureBootEnable,
0,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS
);
} else {
SecureBootEnable = *(UINT8 *) Data;
}
} else if (mPlatformMode == USER_MODE) {
//
// "SecureBootEnable" not exist, initialize it in USER_MODE.
//
SecureBootEnable = SECURE_BOOT_ENABLE;
Status = AuthServiceInternalUpdateVariable (
EFI_SECURE_BOOT_ENABLE_NAME,
&gEfiSecureBootEnableDisableGuid,
&SecureBootEnable,
sizeof (UINT8),
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS
);
if (EFI_ERROR (Status)) {
return Status;
}
}
//
// Create "SecureBoot" variable with BS+RT attribute set.
//
if (SecureBootEnable == SECURE_BOOT_ENABLE && mPlatformMode == USER_MODE) {
SecureBootMode = SECURE_BOOT_MODE_ENABLE;
} else {
SecureBootMode = SECURE_BOOT_MODE_DISABLE;
}
Status = AuthServiceInternalUpdateVariable (
EFI_SECURE_BOOT_MODE_NAME,
&gEfiGlobalVariableGuid,
&SecureBootMode,
sizeof (UINT8),
EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS
);
if (EFI_ERROR (Status)) {
return Status;
}
DEBUG ((EFI_D_INFO, "Variable %s is %x\n", EFI_SETUP_MODE_NAME, mPlatformMode));
DEBUG ((EFI_D_INFO, "Variable %s is %x\n", EFI_SECURE_BOOT_MODE_NAME, SecureBootMode));
DEBUG ((EFI_D_INFO, "Variable %s is %x\n", EFI_SECURE_BOOT_ENABLE_NAME, SecureBootEnable));
//
// Initialize "CustomMode" in STANDARD_SECURE_BOOT_MODE state.
//
@ -455,10 +380,16 @@ AuthVariableLibProcessVariable (
{
EFI_STATUS Status;
//
// Process PK, KEK, Sigdb, AuditMode, DeployedMode separately.
//
if (CompareGuid (VendorGuid, &gEfiGlobalVariableGuid) && (StrCmp (VariableName, EFI_PLATFORM_KEY_NAME) == 0)){
Status = ProcessVarWithPk (VariableName, VendorGuid, Data, DataSize, Attributes, TRUE);
} else if (CompareGuid (VendorGuid, &gEfiGlobalVariableGuid) && (StrCmp (VariableName, EFI_KEY_EXCHANGE_KEY_NAME) == 0)) {
Status = ProcessVarWithPk (VariableName, VendorGuid, Data, DataSize, Attributes, FALSE);
} else if (CompareGuid (VendorGuid, &gEfiGlobalVariableGuid)
&& (StrCmp (VariableName, EFI_AUDIT_MODE_NAME) == 0 || StrCmp (VariableName, EFI_DEPLOYED_MODE_NAME) == 0)) {
Status = ProcessSecureBootModeVar(VariableName, VendorGuid, Data, DataSize, Attributes);
} else if (CompareGuid (VendorGuid, &gEfiImageSecurityDatabaseGuid) &&
((StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE) == 0) ||
(StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE1) == 0) ||

4
SecurityPkg/Library/AuthVariableLib/AuthVariableLib.inf
View File

@ -85,6 +85,10 @@
## PRODUCES ## Variable:L"AuthVarKeyDatabase"
gEfiAuthenticatedVariableGuid
## CONSUMES ## Variable:L"SecureBootMode"
## PRODUCES ## Variable:L"SecureBootMode"
gEdkiiSecureBootModeGuid
gEfiCertTypeRsa2048Sha256Guid ## SOMETIMES_CONSUMES ## GUID # Unique ID for the type of the certificate.
gEfiCertPkcs7Guid ## SOMETIMES_CONSUMES ## GUID # Unique ID for the type of the certificate.
gEfiCertX509Guid ## SOMETIMES_CONSUMES ## GUID # Unique ID for the type of the signature.

642
SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c
View File

@ -711,6 +711,58 @@ GetImageExeInfoTableSize (
return TotalSize;
}
/**
Create signature list based on input signature data and certificate type GUID. Caller is reposible
to free new created SignatureList.
@param[in] SignatureData Signature data in SignatureList.
@param[in] SignatureDataSize Signature data size.
@param[in] CertType Certificate Type.
@param[out] SignatureList Created SignatureList.
@param[out] SignatureListSize Created SignatureListSize.
@return EFI_OUT_OF_RESOURCES The operation is failed due to lack of resources.
@retval EFI_SUCCESS Successfully create signature list.
**/
EFI_STATUS
CreateSignatureList(
IN UINT8 *SignatureData,
IN UINTN SignatureDataSize,
IN EFI_GUID *CertType,
OUT EFI_SIGNATURE_LIST **SignatureList,
OUT UINTN *SignatureListSize
)
{
EFI_SIGNATURE_LIST *SignList;
UINTN SignListSize;
EFI_SIGNATURE_DATA *Signature;
SignList = NULL;
*SignatureList = NULL;
SignListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + SignatureDataSize;
SignList = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignListSize);
if (SignList == NULL) {
return EFI_OUT_OF_RESOURCES;
}
SignList->SignatureHeaderSize = 0;
SignList->SignatureListSize = (UINT32) SignListSize;
SignList->SignatureSize = (UINT32) SignatureDataSize + sizeof (EFI_SIGNATURE_DATA) - 1;
CopyMem (&SignList->SignatureType, CertType, sizeof (EFI_GUID));
DEBUG((EFI_D_INFO, "SignatureDataSize %x\n", SignatureDataSize));
Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignList + sizeof (EFI_SIGNATURE_LIST));
CopyMem (Signature->SignatureData, SignatureData, SignatureDataSize);
*SignatureList = SignList;
*SignatureListSize = SignListSize;
return EFI_SUCCESS;
}
/**
Create an Image Execution Information Table entry and add it to system configuration table.
@ -737,11 +789,13 @@ AddImageExeInfo (
UINTN NewImageExeInfoEntrySize;
UINTN NameStringLen;
UINTN DevicePathSize;
CHAR16 *NameStr;
ImageExeInfoTable = NULL;
NewImageExeInfoTable = NULL;
ImageExeInfoEntry = NULL;
NameStringLen = 0;
NameStr = NULL;
if (DevicePath == NULL) {
return ;
@ -769,7 +823,12 @@ AddImageExeInfo (
}
DevicePathSize = GetDevicePathSize (DevicePath);
//
// Signature size can be odd. Pad after signature to ensure next EXECUTION_INFO entry align
//
NewImageExeInfoEntrySize = sizeof (EFI_IMAGE_EXECUTION_INFO) + NameStringLen + DevicePathSize + SignatureSize;
NewImageExeInfoTable = (EFI_IMAGE_EXECUTION_INFO_TABLE *) AllocateRuntimePool (ImageExeInfoTableSize + NewImageExeInfoEntrySize);
if (NewImageExeInfoTable == NULL) {
return ;
@ -788,19 +847,21 @@ AddImageExeInfo (
WriteUnaligned32 ((UINT32 *) ImageExeInfoEntry, Action);
WriteUnaligned32 ((UINT32 *) ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION)), (UINT32) NewImageExeInfoEntrySize);
NameStr = (CHAR16 *)(ImageExeInfoEntry + 1);
if (Name != NULL) {
CopyMem ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32), Name, NameStringLen);
CopyMem ((UINT8 *) NameStr, Name, NameStringLen);
} else {
ZeroMem ((UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32), sizeof (CHAR16));
ZeroMem ((UINT8 *) NameStr, sizeof (CHAR16));
}
CopyMem (
(UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32) + NameStringLen,
(UINT8 *) NameStr + NameStringLen,
DevicePath,
DevicePathSize
);
if (Signature != NULL) {
CopyMem (
(UINT8 *) ImageExeInfoEntry + sizeof (EFI_IMAGE_EXECUTION_ACTION) + sizeof (UINT32) + NameStringLen + DevicePathSize,
(UINT8 *) NameStr + NameStringLen + DevicePathSize,
Signature,
SignatureSize
);
@ -1087,6 +1148,53 @@ IsTimeZero (
return FALSE;
}
/**
Record multiple certificate list & verification state of a verified image to
IMAGE_EXECUTION_TABLE.
@param[in] CertBuf Certificate list buffer.
@param[in] CertBufLength Certificate list buffer.
@param[in] Action Certificate list action to be record.
@param[in] ImageName Image name.
@param[in] ImageDevicePath Image device path.
**/
VOID
RecordCertListToImageExeuctionTable(
IN UINT8 *CertBuf,
IN UINTN CertBufLength,
IN EFI_IMAGE_EXECUTION_ACTION Action,
IN CHAR16 *ImageName OPTIONAL,
IN CONST EFI_DEVICE_PATH_PROTOCOL *ImageDevicePath OPTIONAL
)
{
UINT8 CertNumber;
UINT8 *CertPtr;
UINTN Index;
UINT8 *Cert;
UINTN CertSize;
EFI_STATUS Status;
EFI_SIGNATURE_LIST *SignatureList;
UINTN SignatureListSize;
CertNumber = (UINT8) (*CertBuf);
CertPtr = CertBuf + 1;
for (Index = 0; Index < CertNumber; Index++) {
CertSize = (UINTN) ReadUnaligned32 ((UINT32 *)CertPtr);
Cert = (UINT8 *)CertPtr + sizeof (UINT32);
//
// Record all cert in cert chain to be passed
//
Status = CreateSignatureList(Cert, CertSize, &gEfiCertX509Guid, &SignatureList, &SignatureListSize);
if (!EFI_ERROR(Status)) {
AddImageExeInfo (Action, ImageName, ImageDevicePath, SignatureList, SignatureListSize);
FreePool (SignatureList);
}
}
}
/**
Check whether the timestamp signature is valid and the signing time is also earlier than
the revocation time.
@ -1199,6 +1307,9 @@ Done:
@param[in] AuthData Pointer to the Authenticode signature retrieved from the signed image.
@param[in] AuthDataSize Size of the Authenticode signature in bytes.
@param[in] IsAuditMode Whether system Secure Boot Mode is in AuditMode.
@param[in] ImageName Name of the image to verify.
@param[in] ImageDevicePath DevicePath of the image to verify.
@retval TRUE Image is forbidden by dbx.
@retval FALSE Image is not forbidden by dbx.
@ -1207,7 +1318,10 @@ Done:
BOOLEAN
IsForbiddenByDbx (
IN UINT8 *AuthData,
IN UINTN AuthDataSize
IN UINTN AuthDataSize,
IN BOOLEAN IsAuditMode,
IN CHAR16 *ImageName OPTIONAL,
IN CONST EFI_DEVICE_PATH_PROTOCOL *ImageDevicePath OPTIONAL
)
{
EFI_STATUS Status;
@ -1230,7 +1344,10 @@ IsForbiddenByDbx (
UINT8 *Cert;
UINTN CertSize;
EFI_TIME RevocationTime;
UINT8 *SignerCert;
UINTN SignerCertLength;
UINT8 *UnchainCert;
UINTN UnchainCertLength;
//
// Variable Initialization
//
@ -1245,6 +1362,10 @@ IsForbiddenByDbx (
BufferLength = 0;
TrustedCert = NULL;
TrustedCertLength = 0;
SignerCert = NULL;
SignerCertLength = 0;
UnchainCert = NULL;
UnchainCertLength = 0;
//
// The image will not be forbidden if dbx can't be got.
@ -1352,21 +1473,54 @@ IsForbiddenByDbx (
}
Done:
if (IsForbidden && IsAuditMode) {
Pkcs7GetCertificatesList(AuthData, AuthDataSize, &SignerCert, &SignerCertLength, &UnchainCert, &UnchainCertLength);
//
// Record all certs in image to be failed
//
if ((SignerCertLength != 0) && (SignerCert != NULL)) {
RecordCertListToImageExeuctionTable(
SignerCert,
SignerCertLength,
EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
ImageName,
ImageDevicePath
);
}
if ((UnchainCertLength != 0) && (UnchainCert != NULL)) {
RecordCertListToImageExeuctionTable(
UnchainCert,
UnchainCertLength,
EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
ImageName,
ImageDevicePath
);
}
}
if (Data != NULL) {
FreePool (Data);
}
Pkcs7FreeSigners (CertBuffer);
Pkcs7FreeSigners (TrustedCert);
Pkcs7FreeSigners (SignerCert);
Pkcs7FreeSigners (UnchainCert);
return IsForbidden;
}
/**
Check whether the image signature can be verified by the trusted certificates in DB database.
@param[in] AuthData Pointer to the Authenticode signature retrieved from signed image.
@param[in] AuthDataSize Size of the Authenticode signature in bytes.
@param[in] IsAuditMode Whether system Secure Boot Mode is in AuditMode.
@param[in] ImageName Name of the image to verify.
@param[in] ImageDevicePath DevicePath of the image to verify.
@retval TRUE Image passed verification using certificate in db.
@retval FALSE Image didn't pass verification using certificate in db.
@ -1375,13 +1529,16 @@ Done:
BOOLEAN
IsAllowedByDb (
IN UINT8 *AuthData,
IN UINTN AuthDataSize
IN UINTN AuthDataSize,
IN BOOLEAN IsAuditMode,
IN CHAR16 *ImageName OPTIONAL,
IN CONST EFI_DEVICE_PATH_PROTOCOL *ImageDevicePath OPTIONAL
)
{
EFI_STATUS Status;
BOOLEAN VerifyStatus;
EFI_SIGNATURE_LIST *CertList;
EFI_SIGNATURE_DATA *Cert;
EFI_SIGNATURE_DATA *CertData;
UINTN DataSize;
UINT8 *Data;
UINT8 *RootCert;
@ -1391,14 +1548,22 @@ IsAllowedByDb (
UINTN DbxDataSize;
UINT8 *DbxData;
EFI_TIME RevocationTime;
UINT8 *SignerCert;
UINTN SignerCertLength;
UINT8 *UnchainCert;
UINTN UnchainCertLength;
Data = NULL;
CertList = NULL;
Cert = NULL;
CertData = NULL;
RootCert = NULL;
DbxData = NULL;
RootCertSize = 0;
VerifyStatus = FALSE;
SignerCert = NULL;
SignerCertLength = 0;
UnchainCert = NULL;
UnchainCertLength = 0;
DataSize = 0;
Status = gRT->GetVariable (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, NULL, &DataSize, NULL);
@ -1419,14 +1584,14 @@ IsAllowedByDb (
CertList = (EFI_SIGNATURE_LIST *) Data;
while ((DataSize > 0) && (DataSize >= CertList->SignatureListSize)) {
if (CompareGuid (&CertList->SignatureType, &gEfiCertX509Guid)) {
Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
CertCount = (CertList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - CertList->SignatureHeaderSize) / CertList->SignatureSize;
for (Index = 0; Index < CertCount; Index++) {
//
// Iterate each Signature Data Node within this CertList for verify.
//
RootCert = Cert->SignatureData;
RootCert = CertData->SignatureData;
RootCertSize = CertList->SignatureSize - sizeof (EFI_GUID);
//
@ -1468,7 +1633,7 @@ IsAllowedByDb (
goto Done;
}
Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) Cert + CertList->SignatureSize);
CertData = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertData + CertList->SignatureSize);
}
}
@ -1478,10 +1643,67 @@ IsAllowedByDb (
}
Done:
if (VerifyStatus) {
SecureBootHook (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, Cert);
SecureBootHook (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid, CertList->SignatureSize, CertData);
}
if (IsAuditMode) {
Pkcs7GetCertificatesList(AuthData, AuthDataSize, &SignerCert, &SignerCertLength, &UnchainCert, &UnchainCertLength);
if (VerifyStatus) {
if ((SignerCertLength != 0) && (SignerCert != NULL)) {
//
// Record all cert in signer's cert chain to be passed
//
RecordCertListToImageExeuctionTable(
SignerCert,
SignerCertLength,
EFI_IMAGE_EXECUTION_AUTH_SIG_PASSED | EFI_IMAGE_EXECUTION_INITIALIZED,
ImageName,
ImageDevicePath
);
}
if ((UnchainCertLength != 0) && (UnchainCert != NULL)) {
//
// Record all certs in unchained certificates lists to be failed
//
RecordCertListToImageExeuctionTable(
UnchainCert,
UnchainCertLength,
EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
ImageName,
ImageDevicePath
);
}
} else {
//
// Record all certs in image to be failed
//
if ((SignerCertLength != 0) && (SignerCert != NULL)) {
RecordCertListToImageExeuctionTable(
SignerCert,
SignerCertLength,
EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
ImageName,
ImageDevicePath
);
}
if ((UnchainCertLength != 0) && (UnchainCert != NULL)) {
RecordCertListToImageExeuctionTable(
UnchainCert,
UnchainCertLength,
EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED,
ImageName,
ImageDevicePath
);
}
}
}
if (Data != NULL) {
FreePool (Data);
}
@ -1489,9 +1711,369 @@ Done:
FreePool (DbxData);
}
Pkcs7FreeSigners (SignerCert);
Pkcs7FreeSigners (UnchainCert);
return VerifyStatus;
}
/**
Provide verification service for signed images in AuditMode, which include both signature validation
and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and
MSFT Authenticode type signatures are supported.
In this implementation, only verify external executables when in AuditMode.
Executables from FV is bypass, so pass in AuthenticationStatus is ignored. Other authentication status
are record into IMAGE_EXECUTION_TABLE.
The image verification policy is:
If the image is signed,
At least one valid signature or at least one hash value of the image must match a record
in the security database "db", and no valid signature nor any hash value of the image may
be reflected in the security database "dbx".
Otherwise, the image is not signed,
The SHA256 hash value of the image must match a record in the security database "db", and
not be reflected in the security data base "dbx".
Caution: This function may receive untrusted input.
PE/COFF image is external input, so this function will validate its data structure
within this image buffer before use.
@param[in] AuthenticationStatus
This is the authentication status returned from the security
measurement services for the input file.
@param[in] File This is a pointer to the device path of the file that is
being dispatched. This will optionally be used for logging.
@param[in] FileBuffer File buffer matches the input file device path.
@param[in] FileSize Size of File buffer matches the input file device path.
@param[in] BootPolicy A boot policy that was used to call LoadImage() UEFI service.
@retval EFI_SUCCESS The authenticate info is sucessfully stored for the file
specified by DevicePath and non-NULL FileBuffer
@retval EFI_ACCESS_DENIED The file specified by File and FileBuffer did not
authenticate, and the platform policy dictates that the DXE
Foundation many not use File.
**/
EFI_STATUS
EFIAPI
ImageVerificationInAuditMode (
IN UINT32 AuthenticationStatus,
IN CONST EFI_DEVICE_PATH_PROTOCOL *File,
IN VOID *FileBuffer,
IN UINTN FileSize,
IN BOOLEAN BootPolicy
)
{
EFI_STATUS Status;
UINT16 Magic;
EFI_IMAGE_DOS_HEADER *DosHdr;
EFI_SIGNATURE_LIST *SignatureList;
EFI_IMAGE_EXECUTION_ACTION Action;
WIN_CERTIFICATE *WinCertificate;
UINT32 Policy;
PE_COFF_LOADER_IMAGE_CONTEXT ImageContext;
UINT32 NumberOfRvaAndSizes;
WIN_CERTIFICATE_EFI_PKCS *PkcsCertData;
WIN_CERTIFICATE_UEFI_GUID *WinCertUefiGuid;
UINT8 *AuthData;
UINTN AuthDataSize;
EFI_IMAGE_DATA_DIRECTORY *SecDataDir;
UINT32 OffSet;
CHAR16 *FilePathStr;
UINTN SignatureListSize;
SignatureList = NULL;
WinCertificate = NULL;
SecDataDir = NULL;
PkcsCertData = NULL;
FilePathStr = NULL;
Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED;
Status = EFI_ACCESS_DENIED;
//
// Check the image type and get policy setting.
//
switch (GetImageType (File)) {
case IMAGE_FROM_FV:
Policy = ALWAYS_EXECUTE;
break;
case IMAGE_FROM_OPTION_ROM:
Policy = PcdGet32 (PcdOptionRomImageVerificationPolicy);
break;
case IMAGE_FROM_REMOVABLE_MEDIA:
Policy = PcdGet32 (PcdRemovableMediaImageVerificationPolicy);
break;
case IMAGE_FROM_FIXED_MEDIA:
Policy = PcdGet32 (PcdFixedMediaImageVerificationPolicy);
break;
default:
Policy = DENY_EXECUTE_ON_SECURITY_VIOLATION;
break;
}
//
// If policy is always/never execute, return directly.
//
if (Policy == ALWAYS_EXECUTE) {
return EFI_SUCCESS;
}
//
// Get Image Device Path Str
//
FilePathStr = ConvertDevicePathToText (File, FALSE, TRUE);
//
// Authentication failed because of (unspecified) firmware security policy
//
if (Policy == NEVER_EXECUTE) {
//
// No signature, record FilePath/FilePathStr only
//
AddImageExeInfo (EFI_IMAGE_EXECUTION_POLICY_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED, FilePathStr, File, NULL, 0);
goto END;
}
//
// The policy QUERY_USER_ON_SECURITY_VIOLATION and ALLOW_EXECUTE_ON_SECURITY_VIOLATION
// violates the UEFI spec and has been removed.
//
ASSERT (Policy != QUERY_USER_ON_SECURITY_VIOLATION && Policy != ALLOW_EXECUTE_ON_SECURITY_VIOLATION);
if (Policy == QUERY_USER_ON_SECURITY_VIOLATION || Policy == ALLOW_EXECUTE_ON_SECURITY_VIOLATION) {
CpuDeadLoop ();
}
//
// Read the Dos header.
//
if (FileBuffer == NULL) {
Status = EFI_INVALID_PARAMETER;
goto END;
}
mImageBase = (UINT8 *) FileBuffer;
mImageSize = FileSize;
ZeroMem (&ImageContext, sizeof (ImageContext));
ImageContext.Handle = (VOID *) FileBuffer;
ImageContext.ImageRead = (PE_COFF_LOADER_READ_FILE) DxeImageVerificationLibImageRead;
//
// Get information about the image being loaded
//
Status = PeCoffLoaderGetImageInfo (&ImageContext);
if (EFI_ERROR (Status)) {
//
// The information can't be got from the invalid PeImage
//
goto END;
}
DosHdr = (EFI_IMAGE_DOS_HEADER *) mImageBase;
if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
//
// DOS image header is present,
// so read the PE header after the DOS image header.
//
mPeCoffHeaderOffset = DosHdr->e_lfanew;
} else {
mPeCoffHeaderOffset = 0;
}
//
// Check PE/COFF image.
//
mNtHeader.Pe32 = (EFI_IMAGE_NT_HEADERS32 *) (mImageBase + mPeCoffHeaderOffset);
if (mNtHeader.Pe32->Signature != EFI_IMAGE_NT_SIGNATURE) {
//
// It is not a valid Pe/Coff file.
//
Status = EFI_ACCESS_DENIED;
goto END;
}
if (mNtHeader.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && mNtHeader.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
//
// NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value
// in the PE/COFF Header. If the MachineType is Itanium(IA64) and the
// Magic value in the OptionalHeader is EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
// then override the magic value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC
//
Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
} else {
//
// Get the magic value from the PE/COFF Optional Header
//
Magic = mNtHeader.Pe32->OptionalHeader.Magic;
}
if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
//
// Use PE32 offset.
//
NumberOfRvaAndSizes = mNtHeader.Pe32->OptionalHeader.NumberOfRvaAndSizes;
if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
}
} else {
//
// Use PE32+ offset.
//
NumberOfRvaAndSizes = mNtHeader.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;
if (NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_SECURITY) {
SecDataDir = (EFI_IMAGE_DATA_DIRECTORY *) &mNtHeader.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
}
}
//
// Start Image Validation.
//
if (SecDataDir == NULL || SecDataDir->Size == 0) {
//
// This image is not signed. The SHA256 hash value of the image must match a record in the security database "db",
// and not be reflected in the security data base "dbx".
//
if (!HashPeImage (HASHALG_SHA256)) {
Status = EFI_ACCESS_DENIED;
goto END;
}
//
// Image Hash is in forbidden database (DBX).
//
if (!IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
//
// Image Hash is in allowed database (DB).
//
if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
Action = EFI_IMAGE_EXECUTION_AUTH_SIG_PASSED | EFI_IMAGE_EXECUTION_INITIALIZED;
}
}
//
// Add HASH digest for image without signature
//
Status = CreateSignatureList(mImageDigest, mImageDigestSize, &mCertType, &SignatureList, &SignatureListSize);
if (!EFI_ERROR(Status)) {
AddImageExeInfo (Action, FilePathStr, File, SignatureList, SignatureListSize);
FreePool (SignatureList);
}
goto END;
}
//
// Verify the signature of the image, multiple signatures are allowed as per PE/COFF Section 4.7
// "Attribute Certificate Table".
// The first certificate starts at offset (SecDataDir->VirtualAddress) from the start of the file.
//
for (OffSet = SecDataDir->VirtualAddress;
OffSet < (SecDataDir->VirtualAddress + SecDataDir->Size);
OffSet += (WinCertificate->dwLength + ALIGN_SIZE (WinCertificate->dwLength))) {
WinCertificate = (WIN_CERTIFICATE *) (mImageBase + OffSet);
if ((SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) <= sizeof (WIN_CERTIFICATE) ||
(SecDataDir->VirtualAddress + SecDataDir->Size - OffSet) < WinCertificate->dwLength) {
break;
}
//
// Verify the image's Authenticode signature, only DER-encoded PKCS#7 signed data is supported.
//
if (WinCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
//
// The certificate is formatted as WIN_CERTIFICATE_EFI_PKCS which is described in the
// Authenticode specification.
//
PkcsCertData = (WIN_CERTIFICATE_EFI_PKCS *) WinCertificate;
if (PkcsCertData->Hdr.dwLength <= sizeof (PkcsCertData->Hdr)) {
break;
}
AuthData = PkcsCertData->CertData;
AuthDataSize = PkcsCertData->Hdr.dwLength - sizeof(PkcsCertData->Hdr);
} else if (WinCertificate->wCertificateType == WIN_CERT_TYPE_EFI_GUID) {
//
// The certificate is formatted as WIN_CERTIFICATE_UEFI_GUID which is described in UEFI Spec.
//
WinCertUefiGuid = (WIN_CERTIFICATE_UEFI_GUID *) WinCertificate;
if (WinCertUefiGuid->Hdr.dwLength <= OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData)) {
break;
}
if (!CompareGuid (&WinCertUefiGuid->CertType, &gEfiCertPkcs7Guid)) {
continue;
}
AuthData = WinCertUefiGuid->CertData;
AuthDataSize = WinCertUefiGuid->Hdr.dwLength - OFFSET_OF(WIN_CERTIFICATE_UEFI_GUID, CertData);
} else {
if (WinCertificate->dwLength < sizeof (WIN_CERTIFICATE)) {
break;
}
continue;
}
Status = HashPeImageByType (AuthData, AuthDataSize);
if (EFI_ERROR (Status)) {
continue;
}
Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED | EFI_IMAGE_EXECUTION_INITIALIZED;
//
// Check the digital signature against the revoked certificate in forbidden database (dbx).
// Check the digital signature against the valid certificate in allowed database (db).
//
if (!IsForbiddenByDbx (AuthData, AuthDataSize, TRUE, FilePathStr, File)) {
IsAllowedByDb (AuthData, AuthDataSize, TRUE, FilePathStr, File);
}
//
// Check the image's hash value.
//
if (!IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, mImageDigest, &mCertType, mImageDigestSize)) {
Action = EFI_IMAGE_EXECUTION_AUTH_SIG_PASSED | EFI_IMAGE_EXECUTION_INITIALIZED;
}
}
//
// Add HASH digest for image with signature
//
Status = CreateSignatureList(mImageDigest, mImageDigestSize, &mCertType, &SignatureList, &SignatureListSize);
if (!EFI_ERROR(Status)) {
AddImageExeInfo (Action, FilePathStr, File, SignatureList, SignatureListSize);
FreePool (SignatureList);
} else {
goto END;
}
}
if (OffSet != (SecDataDir->VirtualAddress + SecDataDir->Size)) {
//
// The Size in Certificate Table or the attribute certicate table is corrupted.
//
Status = EFI_ACCESS_DENIED;
} else {
Status = EFI_SUCCESS;
}
END:
if (FilePathStr != NULL) {
FreePool(FilePathStr);
FilePathStr = NULL;
}
return Status;
}
/**
Provide verification service for signed images, which include both signature validation
and platform policy control. For signature types, both UEFI WIN_CERTIFICATE_UEFI_GUID and
@ -1559,7 +2141,9 @@ DxeImageVerificationHandler (
EFI_IMAGE_EXECUTION_ACTION Action;
WIN_CERTIFICATE *WinCertificate;
UINT32 Policy;
UINT8 *SecureBoot;
UINT8 *VarData;
UINT8 SecureBoot;
UINT8 AuditMode;
PE_COFF_LOADER_IMAGE_CONTEXT ImageContext;
UINT32 NumberOfRvaAndSizes;
WIN_CERTIFICATE_EFI_PKCS *PkcsCertData;
@ -1579,6 +2163,20 @@ DxeImageVerificationHandler (
Status = EFI_ACCESS_DENIED;
VerifyStatus = EFI_ACCESS_DENIED;
GetEfiGlobalVariable2 (EFI_AUDIT_MODE_NAME, (VOID**)&VarData, NULL);
//
// Skip verification if AuditMode variable doesn't exist. AuditMode should always exist
//
if (VarData == NULL) {
return EFI_SUCCESS;
}
AuditMode = *VarData;
FreePool(VarData);
if (AuditMode == AUDIT_MODE_ENABLE) {
return ImageVerificationInAuditMode(AuthenticationStatus, File, FileBuffer, FileSize, BootPolicy);
}
//
// Check the image type and get policy setting.
//
@ -1622,22 +2220,22 @@ DxeImageVerificationHandler (
CpuDeadLoop ();
}
GetEfiGlobalVariable2 (EFI_SECURE_BOOT_MODE_NAME, (VOID**)&SecureBoot, NULL);
GetEfiGlobalVariable2 (EFI_SECURE_BOOT_MODE_NAME, (VOID**)&VarData, NULL);
//
// Skip verification if SecureBoot variable doesn't exist.
//
if (SecureBoot == NULL) {
if (VarData == NULL) {
return EFI_SUCCESS;
}
SecureBoot = *VarData;
FreePool(VarData);
//
// Skip verification if SecureBoot is disabled.
// Skip verification if SecureBoot is disabled but not AuditMode
//
if (*SecureBoot == SECURE_BOOT_MODE_DISABLE) {
FreePool (SecureBoot);
if (SecureBoot == SECURE_BOOT_MODE_DISABLE) {
return EFI_SUCCESS;
}
FreePool (SecureBoot);
//
// Read the Dos header.
@ -1808,7 +2406,7 @@ DxeImageVerificationHandler (
//
// Check the digital signature against the revoked certificate in forbidden database (dbx).
//
if (IsForbiddenByDbx (AuthData, AuthDataSize)) {
if (IsForbiddenByDbx (AuthData, AuthDataSize, FALSE, NULL, NULL)) {
Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED;
VerifyStatus = EFI_ACCESS_DENIED;
break;
@ -1818,7 +2416,7 @@ DxeImageVerificationHandler (
// Check the digital signature against the valid certificate in allowed database (db).
//
if (EFI_ERROR (VerifyStatus)) {
if (IsAllowedByDb (AuthData, AuthDataSize)) {
if (IsAllowedByDb (AuthData, AuthDataSize, FALSE, NULL, NULL)) {
VerifyStatus = EFI_SUCCESS;
}
}