diff options
| -rw-r--r-- | SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c | 333 |
1 files changed, 56 insertions, 277 deletions
diff --git a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c index f83e530c5c..402540eb1b 100644 --- a/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c +++ b/SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.c @@ -783,60 +783,6 @@ AddImageExeInfo ( }
/**
- Discover if the UEFI image is authorized by user's policy setting.
-
- @param[in] Policy Specify platform's policy setting.
-
- @retval EFI_ACCESS_DENIED Image is not allowed to run.
- @retval EFI_SECURITY_VIOLATION Image is deferred.
- @retval EFI_SUCCESS Image is authorized to run.
-
-**/
-EFI_STATUS
-ImageAuthorization (
- IN UINT32 Policy
- )
-{
- EFI_STATUS Status;
- EFI_INPUT_KEY Key;
-
- Status = EFI_ACCESS_DENIED;
-
- switch (Policy) {
-
- case QUERY_USER_ON_SECURITY_VIOLATION:
- do {
- CreatePopUp (EFI_LIGHTGRAY | EFI_BACKGROUND_BLUE, &Key, mNotifyString1, mNotifyString2, NULL);
- if (Key.UnicodeChar == L'Y' || Key.UnicodeChar == L'y') {
- Status = EFI_SUCCESS;
- break;
- } else if (Key.UnicodeChar == L'N' || Key.UnicodeChar == L'n') {
- Status = EFI_ACCESS_DENIED;
- break;
- } else if (Key.UnicodeChar == L'D' || Key.UnicodeChar == L'd') {
- Status = EFI_SECURITY_VIOLATION;
- break;
- }
- } while (TRUE);
- break;
-
- case ALLOW_EXECUTE_ON_SECURITY_VIOLATION:
- Status = EFI_SUCCESS;
- break;
-
- case DEFER_EXECUTE_ON_SECURITY_VIOLATION:
- Status = EFI_SECURITY_VIOLATION;
- break;
-
- case DENY_EXECUTE_ON_SECURITY_VIOLATION:
- Status = EFI_ACCESS_DENIED;
- break;
- }
-
- return Status;
-}
-
-/**
Check whether signature is in specified database.
@param[in] VariableName Name of database variable that is searched in.
@@ -1040,14 +986,7 @@ VerifyCertPkcsSignedData ( }
//
- // 2: Find certificate from KEK database and try to verify authenticode struct.
- //
- if (IsPkcsSignedDataVerifiedBySignatureList (EFI_KEY_EXCHANGE_KEY_NAME, &gEfiGlobalVariableGuid)) {
- return EFI_SUCCESS;
- }
-
- //
- // 3: Find certificate from DB database and try to verify authenticode struct.
+ // 2: Find certificate from DB database and try to verify authenticode struct.
//
if (IsPkcsSignedDataVerifiedBySignatureList (EFI_IMAGE_SECURITY_DATABASE, &gEfiImageSecurityDatabaseGuid)) {
return EFI_SUCCESS;
@@ -1057,139 +996,6 @@ VerifyCertPkcsSignedData ( }
/**
- Verify certificate in WIN_CERTIFICATE_UEFI_GUID format.
-
- @retval EFI_SUCCESS Image pass verification.
- @retval EFI_SECURITY_VIOLATION Image fail verification.
- @retval other error value
-
-**/
-EFI_STATUS
-VerifyCertUefiGuid (
- VOID
- )
-{
- BOOLEAN Status;
- WIN_CERTIFICATE_UEFI_GUID *EfiCert;
- EFI_SIGNATURE_LIST *KekList;
- EFI_SIGNATURE_DATA *KekItem;
- EFI_CERT_BLOCK_RSA_2048_SHA256 *CertBlock;
- VOID *Rsa;
- UINTN KekCount;
- UINTN Index;
- UINTN KekDataSize;
- BOOLEAN IsFound;
- EFI_STATUS Result;
-
- EfiCert = NULL;
- KekList = NULL;
- KekItem = NULL;
- CertBlock = NULL;
- Rsa = NULL;
- Status = FALSE;
- IsFound = FALSE;
- KekDataSize = 0;
-
- EfiCert = (WIN_CERTIFICATE_UEFI_GUID *) (mImageBase + mSecDataDir->VirtualAddress);
- CertBlock = (EFI_CERT_BLOCK_RSA_2048_SHA256 *) EfiCert->CertData;
- if (!CompareGuid (&EfiCert->CertType, &gEfiCertTypeRsa2048Sha256Guid)) {
- //
- // Invalid Certificate Data Type.
- //
- return EFI_SECURITY_VIOLATION;
- }
-
- //
- // Get KEK database variable data size
- //
- Result = gRT->GetVariable (EFI_KEY_EXCHANGE_KEY_NAME, &gEfiGlobalVariableGuid, NULL, &KekDataSize, NULL);
- if (Result != EFI_BUFFER_TOO_SMALL) {
- return EFI_SECURITY_VIOLATION;
- }
-
- //
- // Get KEK database variable.
- //
- GetEfiGlobalVariable2 (EFI_KEY_EXCHANGE_KEY_NAME, (VOID**)&KekList, NULL);
- if (KekList == NULL) {
- return EFI_SECURITY_VIOLATION;
- }
-
- //
- // Enumerate all Kek items in this list to verify the variable certificate data.
- // If anyone is authenticated successfully, it means the variable is correct!
- //
- while ((KekDataSize > 0) && (KekDataSize >= KekList->SignatureListSize)) {
- if (CompareGuid (&KekList->SignatureType, &gEfiCertRsa2048Guid)) {
- KekItem = (EFI_SIGNATURE_DATA *) ((UINT8 *) KekList + sizeof (EFI_SIGNATURE_LIST) + KekList->SignatureHeaderSize);
- KekCount = (KekList->SignatureListSize - sizeof (EFI_SIGNATURE_LIST) - KekList->SignatureHeaderSize) / KekList->SignatureSize;
- for (Index = 0; Index < KekCount; Index++) {
- if (CompareMem (KekItem->SignatureData, CertBlock->PublicKey, EFI_CERT_TYPE_RSA2048_SIZE) == 0) {
- IsFound = TRUE;
- break;
- }
- KekItem = (EFI_SIGNATURE_DATA *) ((UINT8 *) KekItem + KekList->SignatureSize);
- }
- }
- KekDataSize -= KekList->SignatureListSize;
- KekList = (EFI_SIGNATURE_LIST *) ((UINT8 *) KekList + KekList->SignatureListSize);
- }
-
- if (!IsFound) {
- //
- // Signed key is not a trust one.
- //
- goto Done;
- }
-
- //
- // Now, we found the corresponding security policy.
- // Verify the data payload.
- //
- Rsa = RsaNew ();
- if (Rsa == NULL) {
- Status = FALSE;
- goto Done;
- }
-
- //
- // 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, CertBlock->PublicKey, 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,
- mImageDigest,
- mImageDigestSize,
- CertBlock->Signature,
- EFI_CERT_TYPE_RSA2048_SHA256_SIZE
- );
-
-Done:
- if (KekList != NULL) {
- FreePool (KekList);
- }
- if (Rsa != NULL ) {
- RsaFree (Rsa);
- }
- if (Status) {
- return EFI_SUCCESS;
- } else {
- return EFI_SECURITY_VIOLATION;
- }
-}
-
-/**
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
MSFT Authenticode type signatures are supported.
@@ -1198,22 +1004,24 @@ Done: Executables from FV is bypass, so pass in AuthenticationStatus is ignored.
The image verification process is:
- Is the Image signed?
- If yes,
- Does the image verify against a certificate (root or intermediate) in the allowed db?
- Run it
- Image verification fail
- Is the Image's Hash not in forbidden database and the Image's Hash in allowed db?
- Run it
- If no,
- Is the Image's Hash in the forbidden database (DBX)?
- if yes,
- Error out
- Is the Image's Hash in the allowed database (DB)?
- If yes,
- Run it
- If no,
- Error out
+ If the image is signed,
+ If the image's certificate verifies against a certificate (root or intermediate) in the allowed
+ database (DB) and not in the forbidden database (DBX), the certificate verification is passed.
+ If the image's hash digest is in DBX,
+ deny execution.
+ If not,
+ run it.
+ If the Image's certificate verification failed.
+ If the Image's Hash is in DB and not in DBX,
+ run it.
+ Otherwise,
+ deny execution.
+ Otherwise, the image is not signed,
+ Is the Image's Hash in DBX?
+ If yes, deny execution.
+ If not, is the Image's Hash in DB?
+ If yes, run it.
+ If not, deny execution.
Caution: This function may receive untrusted input.
PE/COFF image is external input, so this function will validate its data structure
@@ -1445,25 +1253,7 @@ DxeImageVerificationHandler ( goto Done;
}
- switch (WinCertificate->wCertificateType) {
-
- case WIN_CERT_TYPE_EFI_GUID:
- CertSize = sizeof (WIN_CERTIFICATE_UEFI_GUID) + sizeof (EFI_CERT_BLOCK_RSA_2048_SHA256) - sizeof (UINT8);
- if (WinCertificate->dwLength < CertSize) {
- goto Done;
- }
-
- //
- // Verify UEFI GUID type.
- //
- if (!HashPeImage (HASHALG_SHA256)) {
- goto Done;
- }
-
- VerifyStatus = VerifyCertUefiGuid ();
- break;
-
- case WIN_CERT_TYPE_PKCS_SIGNED_DATA:
+ if (WinCertificate->wCertificateType == WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
//
// Verify Pkcs signed data type.
//
@@ -1471,42 +1261,31 @@ DxeImageVerificationHandler ( if (EFI_ERROR (Status)) {
goto Done;
}
-
+
VerifyStatus = VerifyCertPkcsSignedData ();
+ } else {
+ goto Done;
+ }
+ if (!EFI_ERROR (VerifyStatus)) {
//
- // For image verification against enrolled certificate(root or intermediate),
- // no need to check image's hash in the allowed database.
+ // Verification is passed.
+ // Continue to check the image digest in signature database.
//
- if (!EFI_ERROR (VerifyStatus)) {
- if (!IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
- return EFI_SUCCESS;
- }
+ if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, mImageDigest, &mCertType, mImageDigestSize)) {
+ //
+ // Executable signature verification passes, but is found in forbidden signature database.
+ //
+ Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND;
+ Status = EFI_ACCESS_DENIED;
+ } else {
+ //
+ // For image verification against enrolled X.509 certificate(root or intermediate),
+ // no need to check image's hash in the allowed database.
+ //
+ return EFI_SUCCESS;
}
- break;
-
- default:
- goto Done;
- }
- //
- // Get image hash value as executable's signature.
- //
- SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize;
- SignatureList = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize);
- if (SignatureList == NULL) {
- Status = EFI_OUT_OF_RESOURCES;
- goto Done;
- }
- SignatureList->SignatureHeaderSize = 0;
- SignatureList->SignatureListSize = (UINT32) SignatureListSize;
- SignatureList->SignatureSize = (UINT32) mImageDigestSize;
- CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID));
- Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST));
- CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize);
- //
- // Signature database check after verification.
- //
- if (EFI_ERROR (VerifyStatus)) {
+ } else {
//
// Verification failure.
//
@@ -1521,24 +1300,24 @@ DxeImageVerificationHandler ( Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FAILED;
Status = EFI_ACCESS_DENIED;
}
- } else if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE1, Signature->SignatureData, &mCertType, mImageDigestSize)) {
- //
- // Executable signature verification passes, but is found in forbidden signature database.
- //
- Action = EFI_IMAGE_EXECUTION_AUTH_SIG_FOUND;
- Status = EFI_ACCESS_DENIED;
- } else if (IsSignatureFoundInDatabase (EFI_IMAGE_SECURITY_DATABASE, Signature->SignatureData, &mCertType, mImageDigestSize)) {
- //
- // Executable signature is found in authorized signature database.
- //
- Status = EFI_SUCCESS;
- } else {
+ }
+
+ if (EFI_ERROR (Status)) {
//
- // Executable signature verification passes, but cannot be found in authorized signature database.
- // Get platform policy to determine the action.
+ // Get image hash value as executable's signature.
//
- Action = EFI_IMAGE_EXECUTION_AUTH_SIG_PASSED;
- Status = ImageAuthorization (Policy);
+ SignatureListSize = sizeof (EFI_SIGNATURE_LIST) + sizeof (EFI_SIGNATURE_DATA) - 1 + mImageDigestSize;
+ SignatureList = (EFI_SIGNATURE_LIST *) AllocateZeroPool (SignatureListSize);
+ if (SignatureList == NULL) {
+ Status = EFI_OUT_OF_RESOURCES;
+ goto Done;
+ }
+ SignatureList->SignatureHeaderSize = 0;
+ SignatureList->SignatureListSize = (UINT32) SignatureListSize;
+ SignatureList->SignatureSize = (UINT32) mImageDigestSize;
+ CopyMem (&SignatureList->SignatureType, &mCertType, sizeof (EFI_GUID));
+ Signature = (EFI_SIGNATURE_DATA *) ((UINT8 *) SignatureList + sizeof (EFI_SIGNATURE_LIST));
+ CopyMem (Signature->SignatureData, mImageDigest, mImageDigestSize);
}
Done:
|