mirror of
https://git.proxmox.com/git/efi-boot-shim
synced 2025-11-03 02:21:03 +00:00
Some cleanups
This commit is contained in:
Matthew Garrett
parent
7f0553356c
commit
f898777d22
861
shim.c
861
shim.c
@ -1,13 +1,477 @@
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/*
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* shim - trivial UEFI first-stage bootloader
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*
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* Copyright 2012 Red Hat, Inc <mjg@redhat.com>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* Significant portions of this code are derived from Tianocore
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* (http://tianocore.sf.net) and are Copyright 2009-2012 Intel
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* Corporation.
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*/
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#include <efi.h>
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#include <efilib.h>
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#include <Library/BaseCryptLib.h>
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#include "PeImage.h"
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#define SECOND_STAGE L"grub.efi"
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static EFI_SYSTEM_TABLE *systab;
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static EFI_STATUS (EFIAPI *entry_point) (EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table);
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/*
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* The vendor certificate used for validating the second stage loader
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*/
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#include "cert.h"
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/*
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* Perform basic bounds checking of the intra-image pointers
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*/
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static void *ImageAddress (void *image, int size, unsigned int address)
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{
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if (address > size)
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return NULL;
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return image + address;
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}
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/*
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* Perform the actual relocation
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*/
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static EFI_STATUS relocate_grub (PE_COFF_LOADER_IMAGE_CONTEXT *context,
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void *grubdata)
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{
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EFI_IMAGE_BASE_RELOCATION *RelocBase, *RelocBaseEnd;
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UINT64 Adjust;
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UINT16 *Reloc, *RelocEnd;
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char *Fixup, *FixupBase, *FixupData = NULL;
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UINT16 *Fixup16;
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UINT32 *Fixup32;
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UINT64 *Fixup64;
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int size = context->ImageSize;
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void *ImageEnd = (char *)grubdata + size;
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context->PEHdr->Pe32Plus.OptionalHeader.ImageBase = (UINT64)grubdata;
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if (context->NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_BASERELOC) {
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Print(L"Image has no relocation entry\n");
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return EFI_UNSUPPORTED;
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}
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RelocBase = ImageAddress(grubdata, size, context->RelocDir->VirtualAddress);
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RelocBaseEnd = ImageAddress(grubdata, size, context->RelocDir->VirtualAddress + context->RelocDir->Size - 1);
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if (!RelocBase || !RelocBaseEnd) {
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Print(L"Reloc table overflows binary\n");
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return EFI_UNSUPPORTED;
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}
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Adjust = (UINT64)grubdata - context->ImageAddress;
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while (RelocBase < RelocBaseEnd) {
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Reloc = (UINT16 *) ((char *) RelocBase + sizeof (EFI_IMAGE_BASE_RELOCATION));
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RelocEnd = (UINT16 *) ((char *) RelocBase + RelocBase->SizeOfBlock);
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if ((void *)RelocEnd < grubdata || (void *)RelocEnd > ImageEnd) {
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Print(L"Reloc entry overflows binary\n");
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return EFI_UNSUPPORTED;
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}
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FixupBase = ImageAddress(grubdata, size, RelocBase->VirtualAddress);
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if (!FixupBase) {
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Print(L"Invalid fixupbase\n");
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return EFI_UNSUPPORTED;
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}
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while (Reloc < RelocEnd) {
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Fixup = FixupBase + (*Reloc & 0xFFF);
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switch ((*Reloc) >> 12) {
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case EFI_IMAGE_REL_BASED_ABSOLUTE:
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break;
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case EFI_IMAGE_REL_BASED_HIGH:
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Fixup16 = (UINT16 *) Fixup;
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*Fixup16 = (UINT16) (*Fixup16 + ((UINT16) ((UINT32) Adjust >> 16)));
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if (FixupData != NULL) {
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*(UINT16 *) FixupData = *Fixup16;
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FixupData = FixupData + sizeof (UINT16);
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}
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break;
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case EFI_IMAGE_REL_BASED_LOW:
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Fixup16 = (UINT16 *) Fixup;
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*Fixup16 = (UINT16) (*Fixup16 + (UINT16) Adjust);
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if (FixupData != NULL) {
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*(UINT16 *) FixupData = *Fixup16;
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FixupData = FixupData + sizeof (UINT16);
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}
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break;
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case EFI_IMAGE_REL_BASED_HIGHLOW:
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Fixup32 = (UINT32 *) Fixup;
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*Fixup32 = *Fixup32 + (UINT32) Adjust;
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if (FixupData != NULL) {
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FixupData = ALIGN_POINTER (FixupData, sizeof (UINT32));
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*(UINT32 *)FixupData = *Fixup32;
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FixupData = FixupData + sizeof (UINT32);
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}
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break;
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case EFI_IMAGE_REL_BASED_DIR64:
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Fixup64 = (UINT64 *) Fixup;
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*Fixup64 = *Fixup64 + (UINT64) Adjust;
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if (FixupData != NULL) {
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FixupData = ALIGN_POINTER (FixupData, sizeof(UINT64));
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*(UINT64 *)(FixupData) = *Fixup64;
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FixupData = FixupData + sizeof(UINT64);
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}
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break;
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default:
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Print(L"Unknown relocation\n");
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return EFI_UNSUPPORTED;
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}
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Reloc += 1;
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}
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RelocBase = (EFI_IMAGE_BASE_RELOCATION *) RelocEnd;
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}
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return EFI_SUCCESS;
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}
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/*
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* Check that the signature is valid and matches the binary
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*/
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static EFI_STATUS verify_grub (PE_COFF_LOADER_IMAGE_CONTEXT *context,
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char *grubdata, int grubsize)
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{
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unsigned int size = grubsize;
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unsigned int ctxsize;
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void *ctx;
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UINT8 hash[SHA256_DIGEST_SIZE];
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EFI_STATUS status = EFI_ACCESS_DENIED;
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char *hashbase;
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unsigned int hashsize;
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WIN_CERTIFICATE_EFI_PKCS *cert;
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unsigned int SumOfBytesHashed, SumOfSectionBytes;
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unsigned int index, pos;
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EFI_IMAGE_SECTION_HEADER *Section;
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EFI_IMAGE_SECTION_HEADER *SectionHeader;
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EFI_IMAGE_SECTION_HEADER *SectionCache;
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cert = ImageAddress (grubdata, size, context->SecDir->VirtualAddress);
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if (!cert) {
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Print(L"Certificate located outside the image\n");
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return EFI_INVALID_PARAMETER;
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}
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if (cert->Hdr.wCertificateType != WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
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Print(L"Unsupported certificate type %x\n",
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cert->Hdr.wCertificateType);
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return EFI_UNSUPPORTED;
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}
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/* FIXME: Check which kind of hash */
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ctxsize = Sha256GetContextSize();
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ctx = AllocatePool(ctxsize);
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if (!ctx) {
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Print(L"Unable to allocate memory for hash context\n");
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return EFI_OUT_OF_RESOURCES;
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}
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if (!Sha256Init(ctx)) {
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Print(L"Unable to initialise hash\n");
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status = EFI_OUT_OF_RESOURCES;
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goto done;
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}
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/* Hash start to checksum */
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hashbase = grubdata;
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hashsize = (char *)&context->PEHdr->Pe32.OptionalHeader.CheckSum -
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hashbase;
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if (!(Sha256Update(ctx, hashbase, hashsize))) {
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Print(L"Unable to generate hash\n");
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status = EFI_OUT_OF_RESOURCES;
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goto done;
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}
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/* Hash post-checksum to start of certificate table */
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hashbase = (char *)&context->PEHdr->Pe32.OptionalHeader.CheckSum +
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sizeof (int);
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hashsize = (char *)context->SecDir - hashbase;
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if (!(Sha256Update(ctx, hashbase, hashsize))) {
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Print(L"Unable to generate hash\n");
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status = EFI_OUT_OF_RESOURCES;
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goto done;
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}
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/* Hash end of certificate table to end of image header */
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hashbase = (char *) &context->PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1];
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hashsize = context->PEHdr->Pe32Plus.OptionalHeader.SizeOfHeaders -
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(int) ((char *) (&context->PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1]) - grubdata);
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if (!(Sha256Update(ctx, hashbase, hashsize))) {
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Print(L"Unable to generate hash\n");
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status = EFI_OUT_OF_RESOURCES;
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goto done;
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}
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/* Sort sections */
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SumOfBytesHashed = context->PEHdr->Pe32Plus.OptionalHeader.SizeOfHeaders;
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Section = (EFI_IMAGE_SECTION_HEADER *) (
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(char *)context->PEHdr + sizeof (UINT32) +
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sizeof (EFI_IMAGE_FILE_HEADER) +
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context->PEHdr->Pe32.FileHeader.SizeOfOptionalHeader
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);
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SectionCache = Section;
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for (index = 0, SumOfSectionBytes = 0; index < context->PEHdr->Pe32.FileHeader.NumberOfSections; index++, SectionCache++) {
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SumOfSectionBytes += SectionCache->SizeOfRawData;
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}
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if (SumOfSectionBytes >= grubsize) {
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Print(L"Malformed binary: %x %x\n", SumOfSectionBytes, size);
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status = EFI_INVALID_PARAMETER;
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goto done;
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}
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SectionHeader = (EFI_IMAGE_SECTION_HEADER *) AllocateZeroPool (sizeof (EFI_IMAGE_SECTION_HEADER) * context->PEHdr->Pe32.FileHeader.NumberOfSections);
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if (SectionHeader == NULL) {
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Print(L"Unable to allocate section header\n");
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status = EFI_OUT_OF_RESOURCES;
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goto done;
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}
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/* Sort the section headers */
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for (index = 0; index < context->PEHdr->Pe32.FileHeader.NumberOfSections; index++) {
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pos = index;
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while ((pos > 0) && (Section->PointerToRawData < SectionHeader[pos - 1].PointerToRawData)) {
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CopyMem (&SectionHeader[pos], &SectionHeader[pos - 1], sizeof (EFI_IMAGE_SECTION_HEADER));
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pos--;
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}
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CopyMem (&SectionHeader[pos], Section, sizeof (EFI_IMAGE_SECTION_HEADER));
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Section += 1;
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}
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/* Hash the sections */
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for (index = 0; index < context->PEHdr->Pe32.FileHeader.NumberOfSections; index++) {
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Section = &SectionHeader[index];
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if (Section->SizeOfRawData == 0) {
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continue;
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}
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hashbase = ImageAddress(grubdata, size, Section->PointerToRawData);
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hashsize = (unsigned int) Section->SizeOfRawData;
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if (!hashbase) {
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Print(L"Malformed section header\n");
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return EFI_INVALID_PARAMETER;
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}
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if (!(Sha256Update(ctx, hashbase, hashsize))) {
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Print(L"Unable to generate hash\n");
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status = EFI_OUT_OF_RESOURCES;
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goto done;
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}
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SumOfBytesHashed += Section->SizeOfRawData;
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}
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/* Hash all remaining data */
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if (size > SumOfBytesHashed) {
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hashbase = grubdata + SumOfBytesHashed;
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hashsize = (unsigned int)(
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size -
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context->PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size -
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SumOfBytesHashed);
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if (!(Sha256Update(ctx, hashbase, hashsize))) {
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Print(L"Unable to generate hash\n");
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status = EFI_OUT_OF_RESOURCES;
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goto done;
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}
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}
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if (!(Sha256Final(ctx, hash))) {
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Print(L"Unable to finalise hash\n");
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status = EFI_OUT_OF_RESOURCES;
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goto done;
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}
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if (!AuthenticodeVerify(cert->CertData,
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context->SecDir->Size - sizeof(cert->Hdr),
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vendor_cert, sizeof(cert), hash,
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SHA256_DIGEST_SIZE)) {
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Print(L"Invalid signature\n");
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status = EFI_ACCESS_DENIED;
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} else {
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status = EFI_SUCCESS;
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}
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done:
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if (ctx)
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FreePool(ctx);
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return status;
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}
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/*
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* Read the binary header and grab appropriate information from it
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*/
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static EFI_STATUS read_header(void *grubdata,
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PE_COFF_LOADER_IMAGE_CONTEXT *context)
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{
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EFI_IMAGE_DOS_HEADER *DosHdr = grubdata;
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EFI_IMAGE_OPTIONAL_HEADER_UNION *PEHdr = grubdata;
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if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE)
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PEHdr = (EFI_IMAGE_OPTIONAL_HEADER_UNION *)((char *)grubdata + DosHdr->e_lfanew);
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if (PEHdr->Te.Signature != EFI_IMAGE_NT_SIGNATURE) {
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Print(L"Unsupported image type\n");
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return EFI_UNSUPPORTED;
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}
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if (PEHdr->Pe32.FileHeader.Characteristics & EFI_IMAGE_FILE_RELOCS_STRIPPED) {
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Print(L"Unsupported image - Relocations have been stripped\n");
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return EFI_UNSUPPORTED;
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}
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if (PEHdr->Pe32.OptionalHeader.Magic != EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
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Print(L"Only 64-bit images supported\n");
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return EFI_UNSUPPORTED;
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}
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context->PEHdr = PEHdr;
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context->ImageAddress = PEHdr->Pe32Plus.OptionalHeader.ImageBase;
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context->ImageSize = (UINT64)PEHdr->Pe32Plus.OptionalHeader.SizeOfImage;
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context->SizeOfHeaders = PEHdr->Pe32Plus.OptionalHeader.SizeOfHeaders;
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context->EntryPoint = PEHdr->Pe32Plus.OptionalHeader.AddressOfEntryPoint;
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context->RelocDir = &PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_BASERELOC];
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context->NumberOfRvaAndSizes = PEHdr->Pe32Plus.OptionalHeader.NumberOfRvaAndSizes;
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context->NumberOfSections = PEHdr->Pe32.FileHeader.NumberOfSections;
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context->FirstSection = (EFI_IMAGE_SECTION_HEADER *)((char *)PEHdr + PEHdr->Pe32.FileHeader.SizeOfOptionalHeader + sizeof(UINT32) + sizeof(EFI_IMAGE_FILE_HEADER));
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context->SecDir = (EFI_IMAGE_DATA_DIRECTORY *) &PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
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if (context->SecDir->VirtualAddress >= context->ImageSize) {
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Print(L"Malformed security header\n");
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return EFI_INVALID_PARAMETER;
|
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}
|
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|
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if (context->SecDir->Size == 0) {
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Print(L"Empty security header\n");
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return EFI_INVALID_PARAMETER;
|
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}
|
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|
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return EFI_SUCCESS;
|
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}
|
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|
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/*
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* Once the image has been loaded it needs to be validated and relocated
|
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*/
|
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static EFI_STATUS handle_grub (void *grubdata, int grubsize)
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{
|
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EFI_STATUS efi_status;
|
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char *buffer;
|
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int i, size;
|
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EFI_IMAGE_SECTION_HEADER *Section;
|
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char *base, *end;
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PE_COFF_LOADER_IMAGE_CONTEXT context;
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efi_status = read_header(grubdata, &context);
|
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if (efi_status != EFI_SUCCESS) {
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Print(L"Failed to read header\n");
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return efi_status;
|
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}
|
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|
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efi_status = verify_grub(&context, grubdata, grubsize);
|
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|
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if (efi_status != EFI_SUCCESS) {
|
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Print(L"Verification failed\n");
|
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return efi_status;
|
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}
|
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|
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buffer = AllocatePool(context.ImageSize);
|
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|
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if (!buffer) {
|
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Print(L"Failed to allocate image buffer\n");
|
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return EFI_OUT_OF_RESOURCES;
|
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}
|
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|
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CopyMem(buffer, grubdata, context.SizeOfHeaders);
|
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|
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Section = context.FirstSection;
|
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for (i = 0; i < context.NumberOfSections; i++) {
|
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size = Section->Misc.VirtualSize;
|
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|
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if (size > Section->SizeOfRawData)
|
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size = Section->SizeOfRawData;
|
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|
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base = ImageAddress (buffer, context.ImageSize, Section->VirtualAddress);
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end = ImageAddress (buffer, context.ImageSize, Section->VirtualAddress + size - 1);
|
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|
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if (!base || !end) {
|
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Print(L"Invalid section size\n");
|
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return EFI_UNSUPPORTED;
|
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}
|
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|
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if (Section->SizeOfRawData > 0)
|
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CopyMem(base, grubdata + Section->PointerToRawData, size);
|
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|
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if (size < Section->Misc.VirtualSize)
|
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ZeroMem (base + size, Section->Misc.VirtualSize - size);
|
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|
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Section += 1;
|
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}
|
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|
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efi_status = relocate_grub(&context, buffer);
|
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|
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if (efi_status != EFI_SUCCESS) {
|
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Print(L"Relocation failed\n");
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||||
return efi_status;
|
||||
}
|
||||
|
||||
entry_point = ImageAddress(buffer, context.ImageSize, context.EntryPoint);
|
||||
if (!entry_point) {
|
||||
Print(L"Invalid entry point\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
return EFI_SUCCESS;
|
||||
}
|
||||
|
||||
/*
|
||||
* Locate the second stage bootloader and read it into a buffer
|
||||
*/
|
||||
static EFI_STATUS load_grub (EFI_HANDLE image_handle, void **grubdata,
|
||||
int *grubsize)
|
||||
{
|
||||
@ -111,14 +575,14 @@ static EFI_STATUS load_grub (EFI_HANDLE image_handle, void **grubdata,
|
||||
}
|
||||
}
|
||||
|
||||
PathName = AllocatePool(StrLen(Dir) + StrLen(L"grub.efi"));
|
||||
PathName = AllocatePool(StrLen(Dir) + StrLen(SECOND_STAGE));
|
||||
|
||||
if (!PathName)
|
||||
return EFI_LOAD_ERROR;
|
||||
|
||||
StrCpy(PathName, Dir);
|
||||
|
||||
StrCat(PathName, L"grub.efi");
|
||||
StrCat(PathName, SECOND_STAGE);
|
||||
|
||||
efi_status = uefi_call_wrapper(root->Open, 5, root, &grub, PathName,
|
||||
EFI_FILE_MODE_READ, 0);
|
||||
@ -173,399 +637,6 @@ static EFI_STATUS load_grub (EFI_HANDLE image_handle, void **grubdata,
|
||||
return EFI_SUCCESS;
|
||||
}
|
||||
|
||||
static EFI_STATUS read_header(void *grubdata, PE_COFF_LOADER_IMAGE_CONTEXT *context)
|
||||
{
|
||||
EFI_IMAGE_DOS_HEADER *DosHdr = grubdata;
|
||||
EFI_IMAGE_OPTIONAL_HEADER_UNION *PEHdr = grubdata;
|
||||
|
||||
if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE)
|
||||
PEHdr = (EFI_IMAGE_OPTIONAL_HEADER_UNION *)((char *)grubdata + DosHdr->e_lfanew);
|
||||
|
||||
if (PEHdr->Te.Signature != EFI_IMAGE_NT_SIGNATURE) {
|
||||
Print(L"Unsupported image type\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
if (PEHdr->Pe32.FileHeader.Characteristics & EFI_IMAGE_FILE_RELOCS_STRIPPED) {
|
||||
Print(L"Unsupported image - Relocations have been stripped\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
if (PEHdr->Pe32.OptionalHeader.Magic != EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
|
||||
Print(L"Only 64-bit images supported\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
context->PEHdr = PEHdr;
|
||||
context->ImageAddress = PEHdr->Pe32Plus.OptionalHeader.ImageBase;
|
||||
context->ImageSize = (UINT64)PEHdr->Pe32Plus.OptionalHeader.SizeOfImage;
|
||||
context->SizeOfHeaders = PEHdr->Pe32Plus.OptionalHeader.SizeOfHeaders;
|
||||
context->EntryPoint = PEHdr->Pe32Plus.OptionalHeader.AddressOfEntryPoint;
|
||||
context->RelocDir = &PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_BASERELOC];
|
||||
context->NumberOfRvaAndSizes = PEHdr->Pe32Plus.OptionalHeader.NumberOfRvaAndSizes;
|
||||
context->NumberOfSections = PEHdr->Pe32.FileHeader.NumberOfSections;
|
||||
context->FirstSection = (EFI_IMAGE_SECTION_HEADER *)((char *)PEHdr + PEHdr->Pe32.FileHeader.SizeOfOptionalHeader + sizeof(UINT32) + sizeof(EFI_IMAGE_FILE_HEADER));
|
||||
context->SecDir = (EFI_IMAGE_DATA_DIRECTORY *) &PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY];
|
||||
|
||||
if (context->SecDir->VirtualAddress >= context->ImageSize) {
|
||||
Print(L"Malformed security header\n");
|
||||
return EFI_INVALID_PARAMETER;
|
||||
}
|
||||
|
||||
if (context->SecDir->Size == 0) {
|
||||
Print(L"Empty security header\n");
|
||||
return EFI_INVALID_PARAMETER;
|
||||
}
|
||||
|
||||
return EFI_SUCCESS;
|
||||
}
|
||||
|
||||
static void *ImageAddress (void *image, int size, unsigned int address)
|
||||
{
|
||||
if (address > size)
|
||||
return NULL;
|
||||
|
||||
return image + address;
|
||||
}
|
||||
|
||||
static EFI_STATUS verify_grub (PE_COFF_LOADER_IMAGE_CONTEXT *context, char *grubdata, int grubsize)
|
||||
{
|
||||
unsigned int size = grubsize;
|
||||
unsigned int ctxsize;
|
||||
void *ctx;
|
||||
UINT8 hash[SHA256_DIGEST_SIZE];
|
||||
EFI_STATUS status = EFI_ACCESS_DENIED;
|
||||
char *hashbase;
|
||||
unsigned int hashsize;
|
||||
WIN_CERTIFICATE_EFI_PKCS *cer;
|
||||
unsigned int SumOfBytesHashed, SumOfSectionBytes;
|
||||
unsigned int index, pos;
|
||||
EFI_IMAGE_SECTION_HEADER *Section;
|
||||
EFI_IMAGE_SECTION_HEADER *SectionHeader;
|
||||
EFI_IMAGE_SECTION_HEADER *SectionCache;
|
||||
|
||||
cert = ImageAddress (grubdata, size, context->SecDir->VirtualAddress);
|
||||
|
||||
if (cer->Hdr.wCertificateType != WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
|
||||
Print(L"Unsupported certificate type %x\n",
|
||||
cert->Hdr.wCertificateType);
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
/* Check which kind of hash */
|
||||
|
||||
ctxsize = Sha256GetContextSize();
|
||||
ctx = AllocatePool(ctxsize);
|
||||
|
||||
if (!ctx) {
|
||||
Print(L"Unable to allocate memory for hash context\n");
|
||||
return EFI_OUT_OF_RESOURCES;
|
||||
}
|
||||
|
||||
if (!Sha256Init(ctx)) {
|
||||
Print(L"Unable to initialise hash\n");
|
||||
status = EFI_OUT_OF_RESOURCES;
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* Hash start to checksum */
|
||||
hashbase = grubdata;
|
||||
hashsize = (char *)&context->PEHdr->Pe32.OptionalHeader.CheckSum -
|
||||
hashbase;
|
||||
|
||||
if (!(Sha256Update(ctx, hashbase, hashsize))) {
|
||||
Print(L"Unable to generate hash\n");
|
||||
status = EFI_OUT_OF_RESOURCES;
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* Hash post-checksum to start of certificate table */
|
||||
hashbase = (char *)&context->PEHdr->Pe32.OptionalHeader.CheckSum +
|
||||
sizeof (int);
|
||||
hashsize = (char *)context->SecDir - hashbase;
|
||||
|
||||
if (!(Sha256Update(ctx, hashbase, hashsize))) {
|
||||
Print(L"Unable to generate hash\n");
|
||||
status = EFI_OUT_OF_RESOURCES;
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* Hash end of certificate table to end of image header */
|
||||
hashbase = (char *) &context->PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1];
|
||||
hashsize = context->PEHdr->Pe32Plus.OptionalHeader.SizeOfHeaders -
|
||||
(int) ((char *) (&context->PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY + 1]) - grubdata);
|
||||
if (!(Sha256Update(ctx, hashbase, hashsize))) {
|
||||
Print(L"Unable to generate hash\n");
|
||||
status = EFI_OUT_OF_RESOURCES;
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* Sort sections and hash SizeOfRawData of each section */
|
||||
SumOfBytesHashed = context->PEHdr->Pe32Plus.OptionalHeader.SizeOfHeaders;
|
||||
|
||||
Section = (EFI_IMAGE_SECTION_HEADER *) (
|
||||
(char *)context->PEHdr + sizeof (UINT32) +
|
||||
sizeof (EFI_IMAGE_FILE_HEADER) +
|
||||
context->PEHdr->Pe32.FileHeader.SizeOfOptionalHeader
|
||||
);
|
||||
|
||||
SectionCache = Section;
|
||||
|
||||
for (index = 0, SumOfSectionBytes = 0; index < context->PEHdr->Pe32.FileHeader.NumberOfSections; index++, SectionCache++) {
|
||||
SumOfSectionBytes += SectionCache->SizeOfRawData;
|
||||
}
|
||||
|
||||
if (SumOfSectionBytes >= grubsize) {
|
||||
Print(L"Malformed binary: %x %x\n", SumOfSectionBytes, size);
|
||||
status = EFI_INVALID_PARAMETER;
|
||||
goto done;
|
||||
}
|
||||
|
||||
SectionHeader = (EFI_IMAGE_SECTION_HEADER *) AllocateZeroPool (sizeof (EFI_IMAGE_SECTION_HEADER) * context->PEHdr->Pe32.FileHeader.NumberOfSections);
|
||||
if (SectionHeader == NULL) {
|
||||
Print(L"Unable to allocate section header\n");
|
||||
status = EFI_OUT_OF_RESOURCES;
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* Sort the section headers */
|
||||
for (index = 0; index < context->PEHdr->Pe32.FileHeader.NumberOfSections; index++) {
|
||||
pos = index;
|
||||
while ((pos > 0) && (Section->PointerToRawData < SectionHeader[pos - 1].PointerToRawData)) {
|
||||
CopyMem (&SectionHeader[pos], &SectionHeader[pos - 1], sizeof (EFI_IMAGE_SECTION_HEADER));
|
||||
pos--;
|
||||
}
|
||||
CopyMem (&SectionHeader[pos], Section, sizeof (EFI_IMAGE_SECTION_HEADER));
|
||||
Section += 1;
|
||||
}
|
||||
|
||||
/* Hash the sections */
|
||||
for (index = 0; index < context->PEHdr->Pe32.FileHeader.NumberOfSections; index++) {
|
||||
Section = &SectionHeader[index];
|
||||
if (Section->SizeOfRawData == 0) {
|
||||
continue;
|
||||
}
|
||||
hashbase = ImageAddress(grubdata, size, Section->PointerToRawData);
|
||||
hashsize = (unsigned int) Section->SizeOfRawData;
|
||||
|
||||
if (!(Sha256Update(ctx, hashbase, hashsize))) {
|
||||
Print(L"Unable to generate hash\n");
|
||||
status = EFI_OUT_OF_RESOURCES;
|
||||
goto done;
|
||||
}
|
||||
SumOfBytesHashed += Section->SizeOfRawData;
|
||||
}
|
||||
|
||||
/* Hash all remaining data */
|
||||
if (size > SumOfBytesHashed) {
|
||||
hashbase = grubdata + SumOfBytesHashed;
|
||||
hashsize = (unsigned int)(
|
||||
size -
|
||||
context->PEHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_SECURITY].Size -
|
||||
SumOfBytesHashed);
|
||||
|
||||
if (!(Sha256Update(ctx, hashbase, hashsize))) {
|
||||
Print(L"Unable to generate hash\n");
|
||||
status = EFI_OUT_OF_RESOURCES;
|
||||
goto done;
|
||||
}
|
||||
}
|
||||
|
||||
if (!(Sha256Final(ctx, hash))) {
|
||||
Print(L"Unable to finalise hash\n");
|
||||
status = EFI_OUT_OF_RESOURCES;
|
||||
goto done;
|
||||
}
|
||||
|
||||
if (!AuthenticodeVerify(WinCertificate->CertData,
|
||||
context->SecDir->Size - sizeof(WinCertificate->Hdr),
|
||||
cert, sizeof(cert), hash,
|
||||
SHA256_DIGEST_SIZE)) {
|
||||
Print(L"Invalid signature\n");
|
||||
status = EFI_ACCESS_DENIED;
|
||||
} else {
|
||||
status = EFI_SUCCESS;
|
||||
}
|
||||
|
||||
done:
|
||||
if (ctx)
|
||||
FreePool(ctx);
|
||||
|
||||
return status;
|
||||
}
|
||||
|
||||
static EFI_STATUS relocate_grub (PE_COFF_LOADER_IMAGE_CONTEXT *context, void *grubdata)
|
||||
{
|
||||
EFI_IMAGE_BASE_RELOCATION *RelocBase, *RelocBaseEnd;
|
||||
UINT64 Adjust;
|
||||
UINT16 *Reloc, *RelocEnd;
|
||||
char *Fixup, *FixupBase, *FixupData = NULL;
|
||||
UINT16 *Fixup16;
|
||||
UINT32 *Fixup32;
|
||||
UINT64 *Fixup64;
|
||||
int size = context->ImageSize;
|
||||
void *ImageEnd = (char *)grubdata + size;
|
||||
|
||||
context->PEHdr->Pe32Plus.OptionalHeader.ImageBase = (UINT64)grubdata;
|
||||
|
||||
if (context->NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_BASERELOC) {
|
||||
Print(L"Image has no relocation entry\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
RelocBase = ImageAddress(grubdata, size, context->RelocDir->VirtualAddress);
|
||||
RelocBaseEnd = ImageAddress(grubdata, size, context->RelocDir->VirtualAddress + context->RelocDir->Size - 1);
|
||||
|
||||
if (!RelocBase || !RelocBaseEnd) {
|
||||
Print(L"Reloc table overflows binary\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
Adjust = (UINT64)grubdata - context->ImageAddress;
|
||||
|
||||
while (RelocBase < RelocBaseEnd) {
|
||||
Reloc = (UINT16 *) ((char *) RelocBase + sizeof (EFI_IMAGE_BASE_RELOCATION));
|
||||
RelocEnd = (UINT16 *) ((char *) RelocBase + RelocBase->SizeOfBlock);
|
||||
|
||||
if ((void *)RelocEnd < grubdata || (void *)RelocEnd > ImageEnd) {
|
||||
Print(L"Reloc entry overflows binary\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
FixupBase = ImageAddress(grubdata, size, RelocBase->VirtualAddress);
|
||||
if (!FixupBase) {
|
||||
Print(L"Invalid fixupbase\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
while (Reloc < RelocEnd) {
|
||||
Fixup = FixupBase + (*Reloc & 0xFFF);
|
||||
switch ((*Reloc) >> 12) {
|
||||
case EFI_IMAGE_REL_BASED_ABSOLUTE:
|
||||
break;
|
||||
|
||||
case EFI_IMAGE_REL_BASED_HIGH:
|
||||
Fixup16 = (UINT16 *) Fixup;
|
||||
*Fixup16 = (UINT16) (*Fixup16 + ((UINT16) ((UINT32) Adjust >> 16)));
|
||||
if (FixupData != NULL) {
|
||||
*(UINT16 *) FixupData = *Fixup16;
|
||||
FixupData = FixupData + sizeof (UINT16);
|
||||
}
|
||||
break;
|
||||
|
||||
case EFI_IMAGE_REL_BASED_LOW:
|
||||
Fixup16 = (UINT16 *) Fixup;
|
||||
*Fixup16 = (UINT16) (*Fixup16 + (UINT16) Adjust);
|
||||
if (FixupData != NULL) {
|
||||
*(UINT16 *) FixupData = *Fixup16;
|
||||
FixupData = FixupData + sizeof (UINT16);
|
||||
}
|
||||
break;
|
||||
|
||||
case EFI_IMAGE_REL_BASED_HIGHLOW:
|
||||
Fixup32 = (UINT32 *) Fixup;
|
||||
*Fixup32 = *Fixup32 + (UINT32) Adjust;
|
||||
if (FixupData != NULL) {
|
||||
FixupData = ALIGN_POINTER (FixupData, sizeof (UINT32));
|
||||
*(UINT32 *)FixupData = *Fixup32;
|
||||
FixupData = FixupData + sizeof (UINT32);
|
||||
}
|
||||
break;
|
||||
|
||||
case EFI_IMAGE_REL_BASED_DIR64:
|
||||
Fixup64 = (UINT64 *) Fixup;
|
||||
*Fixup64 = *Fixup64 + (UINT64) Adjust;
|
||||
if (FixupData != NULL) {
|
||||
FixupData = ALIGN_POINTER (FixupData, sizeof(UINT64));
|
||||
*(UINT64 *)(FixupData) = *Fixup64;
|
||||
FixupData = FixupData + sizeof(UINT64);
|
||||
}
|
||||
break;
|
||||
|
||||
default:
|
||||
Print(L"Unknown relocation\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
Reloc += 1;
|
||||
}
|
||||
RelocBase = (EFI_IMAGE_BASE_RELOCATION *) RelocEnd;
|
||||
}
|
||||
|
||||
return EFI_SUCCESS;
|
||||
|
||||
}
|
||||
|
||||
static EFI_STATUS handle_grub (void *grubdata, int grubsize)
|
||||
{
|
||||
EFI_STATUS efi_status;
|
||||
char *buffer;
|
||||
int i, size;
|
||||
EFI_IMAGE_SECTION_HEADER *Section;
|
||||
char *base, *end;
|
||||
PE_COFF_LOADER_IMAGE_CONTEXT context;
|
||||
|
||||
efi_status = read_header(grubdata, &context);
|
||||
if (efi_status != EFI_SUCCESS) {
|
||||
Print(L"Failed to read header\n");
|
||||
return efi_status;
|
||||
}
|
||||
|
||||
efi_status = verify_grub(&context, grubdata, grubsize);
|
||||
|
||||
if (efi_status != EFI_SUCCESS) {
|
||||
Print(L"Verification failed\n");
|
||||
return efi_status;
|
||||
}
|
||||
|
||||
buffer = AllocatePool(context.ImageSize);
|
||||
|
||||
if (!buffer) {
|
||||
Print(L"Failed to allocate image buffer\n");
|
||||
return EFI_OUT_OF_RESOURCES;
|
||||
}
|
||||
|
||||
CopyMem(buffer, grubdata, context.SizeOfHeaders);
|
||||
|
||||
Section = context.FirstSection;
|
||||
for (i = 0; i < context.NumberOfSections; i++) {
|
||||
size = Section->Misc.VirtualSize;
|
||||
|
||||
if (size > Section->SizeOfRawData)
|
||||
size = Section->SizeOfRawData;
|
||||
|
||||
base = ImageAddress (buffer, context.ImageSize, Section->VirtualAddress);
|
||||
end = ImageAddress (buffer, context.ImageSize, Section->VirtualAddress + size - 1);
|
||||
|
||||
if (!base || !end) {
|
||||
Print(L"Invalid section size\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
if (Section->SizeOfRawData > 0)
|
||||
CopyMem(base, grubdata + Section->PointerToRawData, size);
|
||||
|
||||
if (size < Section->Misc.VirtualSize)
|
||||
ZeroMem (base + size, Section->Misc.VirtualSize - size);
|
||||
|
||||
Section += 1;
|
||||
}
|
||||
|
||||
efi_status = relocate_grub(&context, buffer);
|
||||
|
||||
if (efi_status != EFI_SUCCESS) {
|
||||
Print(L"Relocation failed\n");
|
||||
return efi_status;
|
||||
}
|
||||
|
||||
entry_point = ImageAddress(buffer, context.ImageSize, context.EntryPoint);
|
||||
if (!entry_point) {
|
||||
Print(L"Invalid entry point\n");
|
||||
return EFI_UNSUPPORTED;
|
||||
}
|
||||
|
||||
return EFI_SUCCESS;
|
||||
}
|
||||
|
||||
EFI_STATUS efi_main (EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *passed_systab)
|
||||
{
|
||||
EFI_STATUS efi_status;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user