diff options
Diffstat (limited to 'shim.c')
| -rw-r--r-- | shim.c | 86 |
1 files changed, 61 insertions, 25 deletions
@@ -51,6 +51,8 @@ static EFI_STATUS (EFIAPI *entry_point) (EFI_HANDLE image_handle, EFI_SYSTEM_TAB */ extern UINT8 vendor_cert[]; extern UINT32 vendor_cert_size; +extern EFI_SIGNATURE_LIST *vendor_dbx; +extern UINT32 vendor_dbx_size; #define EFI_IMAGE_SECURITY_DATABASE_GUID { 0xd719b2cb, 0x3d3a, 0x4596, { 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f }} @@ -209,26 +211,16 @@ static EFI_STATUS relocate_coff (PE_COFF_LOADER_IMAGE_CONTEXT *context, return EFI_SUCCESS; } -static CHECK_STATUS check_db_cert(CHAR16 *dbname, EFI_GUID guid, - WIN_CERTIFICATE_EFI_PKCS *data, UINT8 *hash) +static CHECK_STATUS check_db_cert_in_ram(EFI_SIGNATURE_LIST *CertList, + UINTN dbsize, + WIN_CERTIFICATE_EFI_PKCS *data, + UINT8 *hash) { - EFI_STATUS efi_status; - EFI_SIGNATURE_LIST *CertList; EFI_SIGNATURE_DATA *Cert; - UINTN dbsize = 0; UINTN CertCount, Index; - UINT32 attributes; BOOLEAN IsFound = FALSE; - void *db; EFI_GUID CertType = EfiCertX509Guid; - efi_status = get_variable(dbname, guid, &attributes, &dbsize, &db); - - if (efi_status != EFI_SUCCESS) - return VAR_NOT_FOUND; - - CertList = db; - while ((dbsize > 0) && (dbsize >= CertList->SignatureListSize)) { if (CompareGuid (&CertList->SignatureType, &CertType) == 0) { CertCount = (CertList->SignatureListSize - CertList->SignatureHeaderSize) / CertList->SignatureSize; @@ -250,34 +242,44 @@ static CHECK_STATUS check_db_cert(CHAR16 *dbname, EFI_GUID guid, CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); } - FreePool(db); - if (IsFound) return DATA_FOUND; return DATA_NOT_FOUND; } -static CHECK_STATUS check_db_hash(CHAR16 *dbname, EFI_GUID guid, UINT8 *data, - int SignatureSize, EFI_GUID CertType) +static CHECK_STATUS check_db_cert(CHAR16 *dbname, EFI_GUID guid, + WIN_CERTIFICATE_EFI_PKCS *data, UINT8 *hash) { + CHECK_STATUS rc; EFI_STATUS efi_status; EFI_SIGNATURE_LIST *CertList; - EFI_SIGNATURE_DATA *Cert; UINTN dbsize = 0; - UINTN CertCount, Index; UINT32 attributes; - BOOLEAN IsFound = FALSE; void *db; efi_status = get_variable(dbname, guid, &attributes, &dbsize, &db); - if (efi_status != EFI_SUCCESS) { + if (efi_status != EFI_SUCCESS) return VAR_NOT_FOUND; - } CertList = db; + rc = check_db_cert_in_ram(CertList, dbsize, data, hash); + + FreePool(db); + + return rc; +} + +static CHECK_STATUS check_db_hash_in_ram(EFI_SIGNATURE_LIST *CertList, + UINTN dbsize, UINT8 *data, + int SignatureSize, EFI_GUID CertType) +{ + EFI_SIGNATURE_DATA *Cert; + UINTN CertCount, Index; + BOOLEAN IsFound = FALSE; + while ((dbsize > 0) && (dbsize >= CertList->SignatureListSize)) { CertCount = (CertList->SignatureListSize - CertList->SignatureHeaderSize) / CertList->SignatureSize; Cert = (EFI_SIGNATURE_DATA *) ((UINT8 *) CertList + sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize); @@ -302,19 +304,53 @@ static CHECK_STATUS check_db_hash(CHAR16 *dbname, EFI_GUID guid, UINT8 *data, CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList + CertList->SignatureListSize); } - FreePool(db); - if (IsFound) return DATA_FOUND; return DATA_NOT_FOUND; } +static CHECK_STATUS check_db_hash(CHAR16 *dbname, EFI_GUID guid, UINT8 *data, + int SignatureSize, EFI_GUID CertType) +{ + EFI_STATUS efi_status; + EFI_SIGNATURE_LIST *CertList; + UINT32 attributes; + UINTN dbsize = 0; + void *db; + + efi_status = get_variable(dbname, guid, &attributes, &dbsize, &db); + + if (efi_status != EFI_SUCCESS) { + return VAR_NOT_FOUND; + } + + CertList = db; + + CHECK_STATUS rc = check_db_hash_in_ram(CertList, dbsize, data, + SignatureSize, CertType); + FreePool(db); + return rc; + +} + static EFI_STATUS check_blacklist (WIN_CERTIFICATE_EFI_PKCS *cert, UINT8 *sha256hash, UINT8 *sha1hash) { EFI_GUID secure_var = EFI_IMAGE_SECURITY_DATABASE_GUID; + if (check_db_hash_in_ram(vendor_dbx, vendor_dbx_size, sha256hash, + SHA256_DIGEST_SIZE, EfiHashSha256Guid) == + DATA_NOT_FOUND) + return EFI_ACCESS_DENIED; + if (check_db_hash_in_ram(vendor_dbx, vendor_dbx_size, sha1hash, + SHA1_DIGEST_SIZE, EfiHashSha1Guid) == + DATA_NOT_FOUND) + return EFI_ACCESS_DENIED; + if (check_db_cert_in_ram(vendor_dbx, vendor_dbx_size, cert, + sha256hash) == DATA_NOT_FOUND) + return EFI_ACCESS_DENIED; + if (check_db_hash(L"dbx", secure_var, sha256hash, SHA256_DIGEST_SIZE, EfiHashSha256Guid) == DATA_FOUND) return EFI_ACCESS_DENIED; |