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SecurityPkg: Remove Counter Based AuthVariable support

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Remove counter based auth variable support. also modify several function
descriptors to accommodate the change

Cc: Long Qin <qin.long@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chao Zhang <chao.b.zhang@intel.com>
Reviewed-by: Long Qin <qin.long@intel.com>
This commit is contained in:
Zhang, Chao B
2017-10-24 14:52:10 +08:00
parent b5cbef4eff
commit 0130fddeb3
6 changed files with 37 additions and 628 deletions
Download Patch File Download Diff File Expand all files Collapse all files

501
SecurityPkg/Library/AuthVariableLib/AuthService.c
View File

@@ -136,50 +136,6 @@ AuthServiceInternalUpdateVariable (
);
}
/**
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] KeyIndex Index of associated public key.
@param[in] MonotonicCount Value of associated monotonic count.
@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
AuthServiceInternalUpdateVariableWithMonotonicCount (
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid,
IN VOID *Data,
IN UINTN DataSize,
IN UINT32 Attributes,
IN UINT32 KeyIndex,
IN UINT64 MonotonicCount
)
{
AUTH_VARIABLE_INFO AuthVariableInfo;
ZeroMem (&AuthVariableInfo, sizeof (AuthVariableInfo));
AuthVariableInfo.VariableName = VariableName;
AuthVariableInfo.VendorGuid = VendorGuid;
AuthVariableInfo.Data = Data;
AuthVariableInfo.DataSize = DataSize;
AuthVariableInfo.Attributes = Attributes;
AuthVariableInfo.PubKeyIndex = KeyIndex;
AuthVariableInfo.MonotonicCount = MonotonicCount;
return mAuthVarLibContextIn->UpdateVariable (
&AuthVariableInfo
);
}
/**
Update the variable region with Variable information.
@@ -299,306 +255,6 @@ InCustomMode (
return FALSE;
}
/**
Get available public key index.
@param[in] PubKey Pointer to Public Key data.
@return Public key index, 0 if no any public key index available.
**/
UINT32
GetAvailableKeyIndex (
IN UINT8 *PubKey
)
{
EFI_STATUS Status;
UINT8 *Data;
UINTN DataSize;
UINT8 *Ptr;
UINT32 Index;
BOOLEAN IsFound;
EFI_GUID VendorGuid;
CHAR16 Name[1];
AUTH_VARIABLE_INFO AuthVariableInfo;
UINT32 KeyIndex;
Status = AuthServiceInternalFindVariable (
AUTHVAR_KEYDB_NAME,
&gEfiAuthenticatedVariableGuid,
(VOID **) &Data,
&DataSize
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "Get public key database variable failure, Status = %r\n", Status));
return 0;
}
if (mPubKeyNumber == mMaxKeyNumber) {
Name[0] = 0;
AuthVariableInfo.VariableName = Name;
ZeroMem (&VendorGuid, sizeof (VendorGuid));
AuthVariableInfo.VendorGuid = &VendorGuid;
mPubKeyNumber = 0;
//
// Collect valid key data.
//
do {
Status = mAuthVarLibContextIn->FindNextVariable (AuthVariableInfo.VariableName, AuthVariableInfo.VendorGuid, &AuthVariableInfo);
if (!EFI_ERROR (Status)) {
if (AuthVariableInfo.PubKeyIndex != 0) {
for (Ptr = Data; Ptr < (Data + DataSize); Ptr += sizeof (AUTHVAR_KEY_DB_DATA)) {
if (ReadUnaligned32 (&(((AUTHVAR_KEY_DB_DATA *) Ptr)->KeyIndex)) == AuthVariableInfo.PubKeyIndex) {
//
// Check if the key data has been collected.
//
for (Index = 0; Index < mPubKeyNumber; Index++) {
if (ReadUnaligned32 (&(((AUTHVAR_KEY_DB_DATA *) mPubKeyStore + Index)->KeyIndex)) == AuthVariableInfo.PubKeyIndex) {
break;
}
}
if (Index == mPubKeyNumber) {
//
// New key data.
//
CopyMem ((AUTHVAR_KEY_DB_DATA *) mPubKeyStore + mPubKeyNumber, Ptr, sizeof (AUTHVAR_KEY_DB_DATA));
mPubKeyNumber++;
}
break;
}
}
}
}
} while (Status != EFI_NOT_FOUND);
//
// No available space to add new public key.
//
if (mPubKeyNumber == mMaxKeyNumber) {
return 0;
}
}
//
// Find available public key index.
//
for (KeyIndex = 1; KeyIndex <= mMaxKeyNumber; KeyIndex++) {
IsFound = FALSE;
for (Ptr = mPubKeyStore; Ptr < (mPubKeyStore + mPubKeyNumber * sizeof (AUTHVAR_KEY_DB_DATA)); Ptr += sizeof (AUTHVAR_KEY_DB_DATA)) {
if (ReadUnaligned32 (&(((AUTHVAR_KEY_DB_DATA *) Ptr)->KeyIndex)) == KeyIndex) {
IsFound = TRUE;
break;
}
}
if (!IsFound) {
break;
}
}
return KeyIndex;
}
/**
Add public key in store and return its index.
@param[in] PubKey Input pointer to Public Key data.
@param[in] VariableDataEntry The variable data entry.
@return Index of new added public key.
**/
UINT32
AddPubKeyInStore (
IN UINT8 *PubKey,
IN VARIABLE_ENTRY_CONSISTENCY *VariableDataEntry
)
{
EFI_STATUS Status;
UINT32 Index;
VARIABLE_ENTRY_CONSISTENCY PublicKeyEntry;
UINT32 Attributes;
UINT32 KeyIndex;
if (PubKey == NULL) {
return 0;
}
//
// Check whether the public key entry does exist.
//
for (Index = 0; Index < mPubKeyNumber; Index++) {
if (CompareMem (((AUTHVAR_KEY_DB_DATA *) mPubKeyStore + Index)->KeyData, PubKey, EFI_CERT_TYPE_RSA2048_SIZE) == 0) {
return ReadUnaligned32 (&(((AUTHVAR_KEY_DB_DATA *) mPubKeyStore + Index)->KeyIndex));
}
}
KeyIndex = GetAvailableKeyIndex (PubKey);
if (KeyIndex == 0) {
return 0;
}
//
// Check the variable space for both public key and variable data.
//
PublicKeyEntry.VariableSize = (mPubKeyNumber + 1) * sizeof (AUTHVAR_KEY_DB_DATA);
PublicKeyEntry.Guid = &gEfiAuthenticatedVariableGuid;
PublicKeyEntry.Name = AUTHVAR_KEYDB_NAME;
Attributes = VARIABLE_ATTRIBUTE_NV_BS_RT | EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS;
if (!mAuthVarLibContextIn->CheckRemainingSpaceForConsistency (Attributes, &PublicKeyEntry, VariableDataEntry, NULL)) {
//
// No enough variable space.
//
return 0;
}
WriteUnaligned32 (&(((AUTHVAR_KEY_DB_DATA *) mPubKeyStore + mPubKeyNumber)->KeyIndex), KeyIndex);
CopyMem (((AUTHVAR_KEY_DB_DATA *) mPubKeyStore + mPubKeyNumber)->KeyData, PubKey, EFI_CERT_TYPE_RSA2048_SIZE);
mPubKeyNumber++;
//
// Update public key database variable.
//
Status = AuthServiceInternalUpdateVariable (
AUTHVAR_KEYDB_NAME,
&gEfiAuthenticatedVariableGuid,
mPubKeyStore,
mPubKeyNumber * sizeof (AUTHVAR_KEY_DB_DATA),
Attributes
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "Update public key database variable failure, Status = %r\n", Status));
return 0;
}
return KeyIndex;
}
/**
Verify data payload with AuthInfo in EFI_CERT_TYPE_RSA2048_SHA256_GUID type.
Follow the steps in UEFI2.2.
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] Data Pointer to data with AuthInfo.
@param[in] DataSize Size of Data.
@param[in] PubKey Public key used for verification.
@retval EFI_INVALID_PARAMETER Invalid parameter.
@retval EFI_SECURITY_VIOLATION If authentication failed.
@retval EFI_SUCCESS Authentication successful.
**/
EFI_STATUS
VerifyCounterBasedPayload (
IN UINT8 *Data,
IN UINTN DataSize,
IN UINT8 *PubKey
)
{
BOOLEAN Status;
EFI_VARIABLE_AUTHENTICATION *CertData;
EFI_CERT_BLOCK_RSA_2048_SHA256 *CertBlock;
UINT8 Digest[SHA256_DIGEST_SIZE];
VOID *Rsa;
UINTN PayloadSize;
PayloadSize = DataSize - AUTHINFO_SIZE;
Rsa = NULL;
CertData = NULL;
CertBlock = NULL;
if (Data == NULL || PubKey == NULL) {
return EFI_INVALID_PARAMETER;
}
CertData = (EFI_VARIABLE_AUTHENTICATION *) Data;
CertBlock = (EFI_CERT_BLOCK_RSA_2048_SHA256 *) (CertData->AuthInfo.CertData);
//
// wCertificateType should be WIN_CERT_TYPE_EFI_GUID.
// Cert type should be EFI_CERT_TYPE_RSA2048_SHA256_GUID.
//
if ((CertData->AuthInfo.Hdr.wCertificateType != WIN_CERT_TYPE_EFI_GUID) ||
!CompareGuid (&CertData->AuthInfo.CertType, &gEfiCertTypeRsa2048Sha256Guid)) {
//
// Invalid AuthInfo type, return EFI_SECURITY_VIOLATION.
//
return EFI_SECURITY_VIOLATION;
}
//
// Hash data payload with SHA256.
//
ZeroMem (Digest, SHA256_DIGEST_SIZE);
Status = Sha256Init (mHashCtx);
if (!Status) {
goto Done;
}
Status = Sha256Update (mHashCtx, Data + AUTHINFO_SIZE, PayloadSize);
if (!Status) {
goto Done;
}
//
// Hash Size.
//
Status = Sha256Update (mHashCtx, &PayloadSize, sizeof (UINTN));
if (!Status) {
goto Done;
}
//
// Hash Monotonic Count.
//
Status = Sha256Update (mHashCtx, &CertData->MonotonicCount, sizeof (UINT64));
if (!Status) {
goto Done;
}
Status = Sha256Final (mHashCtx, Digest);
if (!Status) {
goto Done;
}
//
// Generate & Initialize RSA Context.
//
Rsa = RsaNew ();
ASSERT (Rsa != NULL);
//
// Set RSA Key Components.
// NOTE: Only N and E are needed to be set as RSA public key for signature verification.
//
Status = RsaSetKey (Rsa, RsaKeyN, PubKey, EFI_CERT_TYPE_RSA2048_SIZE);
if (!Status) {
goto Done;
}
Status = RsaSetKey (Rsa, RsaKeyE, mRsaE, sizeof (mRsaE));
if (!Status) {
goto Done;
}
//
// Verify the signature.
//
Status = RsaPkcs1Verify (
Rsa,
Digest,
SHA256_DIGEST_SIZE,
CertBlock->Signature,
EFI_CERT_TYPE_RSA2048_SHA256_SIZE
);
Done:
if (Rsa != NULL) {
RsaFree (Rsa);
}
if (Status) {
return EFI_SUCCESS;
} else {
return EFI_SECURITY_VIOLATION;
}
}
/**
Update platform mode.
@@ -1146,7 +802,7 @@ IsDeleteAuthVariable (
}
/**
Process variable with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS/EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS set
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.
@@ -1163,9 +819,9 @@ IsDeleteAuthVariable (
@return EFI_INVALID_PARAMETER Invalid parameter.
@return EFI_WRITE_PROTECTED Variable is write-protected and needs authentication with
EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS set.
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_AUTHENTICATED_WRITE_ACCESS
@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.
@@ -1181,22 +837,8 @@ ProcessVariable (
)
{
EFI_STATUS Status;
BOOLEAN IsDeletion;
BOOLEAN IsFirstTime;
UINT8 *PubKey;
EFI_VARIABLE_AUTHENTICATION *CertData;
EFI_CERT_BLOCK_RSA_2048_SHA256 *CertBlock;
UINT32 KeyIndex;
UINT64 MonotonicCount;
VARIABLE_ENTRY_CONSISTENCY VariableDataEntry;
UINT32 Index;
AUTH_VARIABLE_INFO OrgVariableInfo;
KeyIndex = 0;
CertData = NULL;
CertBlock = NULL;
PubKey = NULL;
IsDeletion = FALSE;
Status = EFI_SUCCESS;
ZeroMem (&OrgVariableInfo, sizeof (OrgVariableInfo));
@@ -1208,7 +850,7 @@ ProcessVariable (
if ((!EFI_ERROR (Status)) && IsDeleteAuthVariable (OrgVariableInfo.Attributes, Data, DataSize, Attributes) && UserPhysicalPresent()) {
//
// Allow the delete operation of common authenticated variable at user physical presence.
// Allow the delete operation of common authenticated variable(AT or AW) at user physical presence.
//
Status = AuthServiceInternalUpdateVariable (
VariableName,
@@ -1232,25 +874,15 @@ ProcessVariable (
}
//
// A time-based authenticated variable and a count-based authenticated variable
// can't be updated by each other.
//
if (OrgVariableInfo.Data != NULL) {
if (((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0) &&
((OrgVariableInfo.Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0)) {
return EFI_SECURITY_VIOLATION;
}
if (((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) &&
((OrgVariableInfo.Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0)) {
return EFI_SECURITY_VIOLATION;
}
}
//
// Process Time-based Authenticated variable.
//
if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
if ((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0) {
//
// Reject Counter Based Auth Variable processing request.
//
return EFI_UNSUPPORTED;
} else if ((Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) != 0) {
//
// Process Time-based Authenticated variable.
//
return VerifyTimeBasedPayloadAndUpdate (
VariableName,
VendorGuid,
@@ -1262,117 +894,20 @@ ProcessVariable (
);
}
//
// Determine if first time SetVariable with the EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS.
//
if ((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0) {
//
// Determine current operation type.
//
if (DataSize == AUTHINFO_SIZE) {
IsDeletion = TRUE;
}
//
// Determine whether this is the first time with EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS set.
//
if (OrgVariableInfo.Data == NULL) {
IsFirstTime = TRUE;
} else if ((OrgVariableInfo.Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) == 0) {
IsFirstTime = TRUE;
} else {
KeyIndex = OrgVariableInfo.PubKeyIndex;
IsFirstTime = FALSE;
}
} else if ((OrgVariableInfo.Data != NULL) &&
((OrgVariableInfo.Attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)) != 0)
) {
if ((OrgVariableInfo.Data != NULL) &&
((OrgVariableInfo.Attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)) != 0)) {
//
// If the variable is already write-protected, it always needs authentication before update.
//
return EFI_WRITE_PROTECTED;
} else {
//
// If without EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS, set and attributes collision.
// That means it is not authenticated variable, just update variable as usual.
//
Status = AuthServiceInternalUpdateVariable (VariableName, VendorGuid, Data, DataSize, Attributes);
return Status;
}
//
// Get PubKey and check Monotonic Count value corresponding to the variable.
// Not authenticated variable, just update variable as usual.
//
CertData = (EFI_VARIABLE_AUTHENTICATION *) Data;
CertBlock = (EFI_CERT_BLOCK_RSA_2048_SHA256 *) (CertData->AuthInfo.CertData);
PubKey = CertBlock->PublicKey;
Status = AuthServiceInternalUpdateVariable (VariableName, VendorGuid, Data, DataSize, Attributes);
return Status;
//
// Update Monotonic Count value.
//
MonotonicCount = CertData->MonotonicCount;
if (!IsFirstTime) {
//
// 2 cases need to check here
// 1. Internal PubKey variable. PubKeyIndex is always 0
// 2. Other counter-based AuthVariable. Check input PubKey.
//
if (KeyIndex == 0) {
return EFI_SECURITY_VIOLATION;
}
for (Index = 0; Index < mPubKeyNumber; Index++) {
if (ReadUnaligned32 (&(((AUTHVAR_KEY_DB_DATA *) mPubKeyStore + Index)->KeyIndex)) == KeyIndex) {
if (CompareMem (((AUTHVAR_KEY_DB_DATA *) mPubKeyStore + Index)->KeyData, PubKey, EFI_CERT_TYPE_RSA2048_SIZE) == 0) {
break;
} else {
return EFI_SECURITY_VIOLATION;
}
}
}
if (Index == mPubKeyNumber) {
return EFI_SECURITY_VIOLATION;
}
//
// Compare the current monotonic count and ensure that it is greater than the last SetVariable
// operation with the EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS attribute set.
//
if (MonotonicCount <= OrgVariableInfo.MonotonicCount) {
//
// Monotonic count check fail, suspicious replay attack, return EFI_SECURITY_VIOLATION.
//
return EFI_SECURITY_VIOLATION;
}
}
//
// Verify the certificate in Data payload.
//
Status = VerifyCounterBasedPayload (Data, DataSize, PubKey);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Now, the signature has been verified!
//
if (IsFirstTime && !IsDeletion) {
VariableDataEntry.VariableSize = DataSize - AUTHINFO_SIZE;
VariableDataEntry.Guid = VendorGuid;
VariableDataEntry.Name = VariableName;
//
// Update public key database variable if need.
//
KeyIndex = AddPubKeyInStore (PubKey, &VariableDataEntry);
if (KeyIndex == 0) {
return EFI_OUT_OF_RESOURCES;
}
}
//
// Verification pass.
//
return AuthServiceInternalUpdateVariableWithMonotonicCount (VariableName, VendorGuid, (UINT8*)Data + AUTHINFO_SIZE, DataSize - AUTHINFO_SIZE, Attributes, KeyIndex, MonotonicCount);
}
/**