#include <common.h>
#include <cpu_func.h>
#include <efi_loader.h>
+#include <malloc.h>
#include <pe.h>
+#include <sort.h>
+#include "../lib/crypto/pkcs7_parser.h"
const efi_guid_t efi_global_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
const efi_guid_t efi_guid_device_path = EFI_DEVICE_PATH_PROTOCOL_GUID;
}
}
+#ifdef CONFIG_EFI_SECURE_BOOT
+/**
+ * cmp_pe_section - compare two sections
+ * @arg1: Pointer to pointer to first section
+ * @arg2: Pointer to pointer to second section
+ *
+ * Compare two sections in PE image.
+ *
+ * Return: -1, 0, 1 respectively if arg1 < arg2, arg1 == arg2 or
+ * arg1 > arg2
+ */
+static int cmp_pe_section(const void *arg1, const void *arg2)
+{
+ const IMAGE_SECTION_HEADER *section1, *section2;
+
+ section1 = *((const IMAGE_SECTION_HEADER **)arg1);
+ section2 = *((const IMAGE_SECTION_HEADER **)arg2);
+
+ if (section1->VirtualAddress < section2->VirtualAddress)
+ return -1;
+ else if (section1->VirtualAddress == section2->VirtualAddress)
+ return 0;
+ else
+ return 1;
+}
+
+/**
+ * efi_image_parse - parse a PE image
+ * @efi: Pointer to image
+ * @len: Size of @efi
+ * @regp: Pointer to a list of regions
+ * @auth: Pointer to a pointer to authentication data in PE
+ * @auth_len: Size of @auth
+ *
+ * Parse image binary in PE32(+) format, assuming that sanity of PE image
+ * has been checked by a caller.
+ * On success, an address of authentication data in @efi and its size will
+ * be returned in @auth and @auth_len, respectively.
+ *
+ * Return: true on success, false on error
+ */
+bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp,
+ WIN_CERTIFICATE **auth, size_t *auth_len)
+{
+ struct efi_image_regions *regs;
+ IMAGE_DOS_HEADER *dos;
+ IMAGE_NT_HEADERS32 *nt;
+ IMAGE_SECTION_HEADER *sections, **sorted;
+ int num_regions, num_sections, i;
+ int ctidx = IMAGE_DIRECTORY_ENTRY_SECURITY;
+ u32 align, size, authsz, authoff;
+ size_t bytes_hashed;
+
+ dos = (void *)efi;
+ nt = (void *)(efi + dos->e_lfanew);
+
+ /*
+ * Count maximum number of regions to be digested.
+ * We don't have to have an exact number here.
+ * See efi_image_region_add()'s in parsing below.
+ */
+ num_regions = 3; /* for header */
+ num_regions += nt->FileHeader.NumberOfSections;
+ num_regions++; /* for extra */
+
+ regs = calloc(sizeof(*regs) + sizeof(struct image_region) * num_regions,
+ 1);
+ if (!regs)
+ goto err;
+ regs->max = num_regions;
+
+ /*
+ * Collect data regions for hash calculation
+ * 1. File headers
+ */
+ if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
+ IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
+ IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
+
+ /* Skip CheckSum */
+ efi_image_region_add(regs, efi, &opt->CheckSum, 0);
+ if (nt64->OptionalHeader.NumberOfRvaAndSizes <= ctidx) {
+ efi_image_region_add(regs,
+ &opt->CheckSum + 1,
+ efi + opt->SizeOfHeaders, 0);
+ } else {
+ /* Skip Certificates Table */
+ efi_image_region_add(regs,
+ &opt->CheckSum + 1,
+ &opt->DataDirectory[ctidx], 0);
+ efi_image_region_add(regs,
+ &opt->DataDirectory[ctidx] + 1,
+ efi + opt->SizeOfHeaders, 0);
+ }
+
+ bytes_hashed = opt->SizeOfHeaders;
+ align = opt->FileAlignment;
+ authoff = opt->DataDirectory[ctidx].VirtualAddress;
+ authsz = opt->DataDirectory[ctidx].Size;
+ } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
+ IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
+
+ efi_image_region_add(regs, efi, &opt->CheckSum, 0);
+ efi_image_region_add(regs, &opt->CheckSum + 1,
+ &opt->DataDirectory[ctidx], 0);
+ efi_image_region_add(regs, &opt->DataDirectory[ctidx] + 1,
+ efi + opt->SizeOfHeaders, 0);
+
+ bytes_hashed = opt->SizeOfHeaders;
+ align = opt->FileAlignment;
+ authoff = opt->DataDirectory[ctidx].VirtualAddress;
+ authsz = opt->DataDirectory[ctidx].Size;
+ } else {
+ debug("%s: Invalid optional header magic %x\n", __func__,
+ nt->OptionalHeader.Magic);
+ goto err;
+ }
+
+ /* 2. Sections */
+ num_sections = nt->FileHeader.NumberOfSections;
+ sections = (void *)((uint8_t *)&nt->OptionalHeader +
+ nt->FileHeader.SizeOfOptionalHeader);
+ sorted = calloc(sizeof(IMAGE_SECTION_HEADER *), num_sections);
+ if (!sorted) {
+ debug("%s: Out of memory\n", __func__);
+ goto err;
+ }
+
+ /*
+ * Make sure the section list is in ascending order.
+ */
+ for (i = 0; i < num_sections; i++)
+ sorted[i] = §ions[i];
+ qsort(sorted, num_sections, sizeof(sorted[0]), cmp_pe_section);
+
+ for (i = 0; i < num_sections; i++) {
+ if (!sorted[i]->SizeOfRawData)
+ continue;
+
+ size = (sorted[i]->SizeOfRawData + align - 1) & ~(align - 1);
+ efi_image_region_add(regs, efi + sorted[i]->PointerToRawData,
+ efi + sorted[i]->PointerToRawData + size,
+ 0);
+ debug("section[%d](%s): raw: 0x%x-0x%x, virt: %x-%x\n",
+ i, sorted[i]->Name,
+ sorted[i]->PointerToRawData,
+ sorted[i]->PointerToRawData + size,
+ sorted[i]->VirtualAddress,
+ sorted[i]->VirtualAddress
+ + sorted[i]->Misc.VirtualSize);
+
+ bytes_hashed += size;
+ }
+ free(sorted);
+
+ /* 3. Extra data excluding Certificates Table */
+ if (bytes_hashed + authsz < len) {
+ debug("extra data for hash: %lu\n",
+ len - (bytes_hashed + authsz));
+ efi_image_region_add(regs, efi + bytes_hashed,
+ efi + len - authsz, 0);
+ }
+
+ /* Return Certificates Table */
+ if (authsz) {
+ if (len < authoff + authsz) {
+ debug("%s: Size for auth too large: %u >= %zu\n",
+ __func__, authsz, len - authoff);
+ goto err;
+ }
+ if (authsz < sizeof(*auth)) {
+ debug("%s: Size for auth too small: %u < %zu\n",
+ __func__, authsz, sizeof(*auth));
+ goto err;
+ }
+ *auth = efi + authoff;
+ *auth_len = authsz;
+ debug("WIN_CERTIFICATE: 0x%x, size: 0x%x\n", authoff, authsz);
+ } else {
+ *auth = NULL;
+ *auth_len = 0;
+ }
+
+ *regp = regs;
+
+ return true;
+
+err:
+ free(regs);
+
+ return false;
+}
+
+/**
+ * efi_image_unsigned_authenticate - authenticate unsigned image with
+ * SHA256 hash
+ * @regs: List of regions to be verified
+ *
+ * If an image is not signed, it doesn't have a signature. In this case,
+ * its message digest is calculated and it will be compared with one of
+ * hash values stored in signature databases.
+ *
+ * Return: true if authenticated, false if not
+ */
+static bool efi_image_unsigned_authenticate(struct efi_image_regions *regs)
+{
+ struct efi_signature_store *db = NULL, *dbx = NULL;
+ bool ret = false;
+
+ dbx = efi_sigstore_parse_sigdb(L"dbx");
+ if (!dbx) {
+ debug("Getting signature database(dbx) failed\n");
+ goto out;
+ }
+
+ db = efi_sigstore_parse_sigdb(L"db");
+ if (!db) {
+ debug("Getting signature database(db) failed\n");
+ goto out;
+ }
+
+ /* try black-list first */
+ if (efi_signature_verify_with_sigdb(regs, NULL, dbx, NULL)) {
+ debug("Image is not signed and rejected by \"dbx\"\n");
+ goto out;
+ }
+
+ /* try white-list */
+ if (efi_signature_verify_with_sigdb(regs, NULL, db, NULL))
+ ret = true;
+ else
+ debug("Image is not signed and not found in \"db\" or \"dbx\"\n");
+
+out:
+ efi_sigstore_free(db);
+ efi_sigstore_free(dbx);
+
+ return ret;
+}
+
+/**
+ * efi_image_authenticate - verify a signature of signed image
+ * @efi: Pointer to image
+ * @efi_size: Size of @efi
+ *
+ * A signed image should have its signature stored in a table of its PE header.
+ * So if an image is signed and only if if its signature is verified using
+ * signature databases, an image is authenticated.
+ * If an image is not signed, its validity is checked by using
+ * efi_image_unsigned_authenticated().
+ * TODO:
+ * When AuditMode==0, if the image's signature is not found in
+ * the authorized database, or is found in the forbidden database,
+ * the image will not be started and instead, information about it
+ * will be placed in this table.
+ * When AuditMode==1, an EFI_IMAGE_EXECUTION_INFO element is created
+ * in the EFI_IMAGE_EXECUTION_INFO_TABLE for every certificate found
+ * in the certificate table of every image that is validated.
+ *
+ * Return: true if authenticated, false if not
+ */
+static bool efi_image_authenticate(void *efi, size_t efi_size)
+{
+ struct efi_image_regions *regs = NULL;
+ WIN_CERTIFICATE *wincerts = NULL, *wincert;
+ size_t wincerts_len;
+ struct pkcs7_message *msg = NULL;
+ struct efi_signature_store *db = NULL, *dbx = NULL;
+ struct x509_certificate *cert = NULL;
+ void *new_efi = NULL;
+ size_t new_efi_size;
+ bool ret = false;
+
+ if (!efi_secure_boot_enabled())
+ return true;
+
+ /*
+ * Size must be 8-byte aligned and the trailing bytes must be
+ * zero'ed. Otherwise hash value may be incorrect.
+ */
+ if (efi_size & 0x7) {
+ new_efi_size = (efi_size + 0x7) & ~0x7ULL;
+ new_efi = calloc(new_efi_size, 1);
+ if (!new_efi)
+ return false;
+ memcpy(new_efi, efi, efi_size);
+ efi = new_efi;
+ efi_size = new_efi_size;
+ }
+
+ if (!efi_image_parse(efi, efi_size, ®s, &wincerts,
+ &wincerts_len)) {
+ debug("Parsing PE executable image failed\n");
+ goto err;
+ }
+
+ if (!wincerts) {
+ /* The image is not signed */
+ ret = efi_image_unsigned_authenticate(regs);
+
+ goto err;
+ }
+
+ /*
+ * verify signature using db and dbx
+ */
+ db = efi_sigstore_parse_sigdb(L"db");
+ if (!db) {
+ debug("Getting signature database(db) failed\n");
+ goto err;
+ }
+
+ dbx = efi_sigstore_parse_sigdb(L"dbx");
+ if (!dbx) {
+ debug("Getting signature database(dbx) failed\n");
+ goto err;
+ }
+
+ /* go through WIN_CERTIFICATE list */
+ for (wincert = wincerts;
+ (void *)wincert < (void *)wincerts + wincerts_len;
+ wincert = (void *)wincert + ALIGN(wincert->dwLength, 8)) {
+ if (wincert->dwLength < sizeof(*wincert)) {
+ debug("%s: dwLength too small: %u < %zu\n",
+ __func__, wincert->dwLength, sizeof(*wincert));
+ goto err;
+ }
+ msg = pkcs7_parse_message((void *)wincert + sizeof(*wincert),
+ wincert->dwLength - sizeof(*wincert));
+ if (!msg) {
+ debug("Parsing image's signature failed\n");
+ goto err;
+ }
+
+ /* try black-list first */
+ if (efi_signature_verify_with_sigdb(regs, msg, dbx, NULL)) {
+ debug("Signature was rejected by \"dbx\"\n");
+ goto err;
+ }
+
+ if (!efi_signature_verify_signers(msg, dbx)) {
+ debug("Signer was rejected by \"dbx\"\n");
+ goto err;
+ } else {
+ ret = true;
+ }
+
+ /* try white-list */
+ if (!efi_signature_verify_with_sigdb(regs, msg, db, &cert)) {
+ debug("Verifying signature with \"db\" failed\n");
+ goto err;
+ } else {
+ ret = true;
+ }
+
+ if (!efi_signature_verify_cert(cert, dbx)) {
+ debug("Certificate was rejected by \"dbx\"\n");
+ goto err;
+ } else {
+ ret = true;
+ }
+ }
+
+err:
+ x509_free_certificate(cert);
+ efi_sigstore_free(db);
+ efi_sigstore_free(dbx);
+ pkcs7_free_message(msg);
+ free(regs);
+ free(new_efi);
+
+ return ret;
+}
+#else
+static bool efi_image_authenticate(void *efi, size_t efi_size)
+{
+ return true;
+}
+#endif /* CONFIG_EFI_SECURE_BOOT */
+
/**
* efi_load_pe() - relocate EFI binary
*
*
* @handle: loaded image handle
* @efi: pointer to the EFI binary
+ * @efi_size: size of @efi binary
* @loaded_image_info: loaded image protocol
* Return: status code
*/
-efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
+efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
+ void *efi, size_t efi_size,
struct efi_loaded_image *loaded_image_info)
{
IMAGE_NT_HEADERS32 *nt;
uint64_t image_base;
unsigned long virt_size = 0;
int supported = 0;
+ efi_status_t ret;
+
+ /* Sanity check for a file header */
+ if (efi_size < sizeof(*dos)) {
+ printf("%s: Truncated DOS Header\n", __func__);
+ ret = EFI_LOAD_ERROR;
+ goto err;
+ }
dos = efi;
if (dos->e_magic != IMAGE_DOS_SIGNATURE) {
printf("%s: Invalid DOS Signature\n", __func__);
- return EFI_LOAD_ERROR;
+ ret = EFI_LOAD_ERROR;
+ goto err;
+ }
+
+ /* assume sizeof(IMAGE_NT_HEADERS32) <= sizeof(IMAGE_NT_HEADERS64) */
+ if (efi_size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS32)) {
+ printf("%s: Invalid offset for Extended Header\n", __func__);
+ ret = EFI_LOAD_ERROR;
+ goto err;
}
nt = (void *) ((char *)efi + dos->e_lfanew);
+ if ((nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) &&
+ (efi_size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS64))) {
+ printf("%s: Invalid offset for Extended Header\n", __func__);
+ ret = EFI_LOAD_ERROR;
+ goto err;
+ }
+
if (nt->Signature != IMAGE_NT_SIGNATURE) {
printf("%s: Invalid NT Signature\n", __func__);
- return EFI_LOAD_ERROR;
+ ret = EFI_LOAD_ERROR;
+ goto err;
}
for (i = 0; machines[i]; i++)
if (!supported) {
printf("%s: Machine type 0x%04x is not supported\n",
__func__, nt->FileHeader.Machine);
- return EFI_LOAD_ERROR;
+ ret = EFI_LOAD_ERROR;
+ goto err;
}
- /* Calculate upper virtual address boundary */
num_sections = nt->FileHeader.NumberOfSections;
sections = (void *)&nt->OptionalHeader +
nt->FileHeader.SizeOfOptionalHeader;
+ if (efi_size < ((void *)sections + sizeof(sections[0]) * num_sections
+ - efi)) {
+ printf("%s: Invalid number of sections: %d\n",
+ __func__, num_sections);
+ ret = EFI_LOAD_ERROR;
+ goto err;
+ }
+
+ /* Authenticate an image */
+ if (efi_image_authenticate(efi, efi_size))
+ handle->auth_status = EFI_IMAGE_AUTH_PASSED;
+ else
+ handle->auth_status = EFI_IMAGE_AUTH_FAILED;
+
+ /* Calculate upper virtual address boundary */
for (i = num_sections - 1; i >= 0; i--) {
IMAGE_SECTION_HEADER *sec = §ions[i];
virt_size = max_t(unsigned long, virt_size,
if (!efi_reloc) {
printf("%s: Could not allocate %lu bytes\n",
__func__, virt_size);
- return EFI_OUT_OF_RESOURCES;
+ ret = EFI_OUT_OF_RESOURCES;
+ goto err;
}
handle->entry = efi_reloc + opt->AddressOfEntryPoint;
rel_size = opt->DataDirectory[rel_idx].Size;
if (!efi_reloc) {
printf("%s: Could not allocate %lu bytes\n",
__func__, virt_size);
- return EFI_OUT_OF_RESOURCES;
+ ret = EFI_OUT_OF_RESOURCES;
+ goto err;
}
handle->entry = efi_reloc + opt->AddressOfEntryPoint;
rel_size = opt->DataDirectory[rel_idx].Size;
} else {
printf("%s: Invalid optional header magic %x\n", __func__,
nt->OptionalHeader.Magic);
- return EFI_LOAD_ERROR;
+ ret = EFI_LOAD_ERROR;
+ goto err;
}
/* Copy PE headers */
- memcpy(efi_reloc, efi, sizeof(*dos) + sizeof(*nt)
- + nt->FileHeader.SizeOfOptionalHeader
- + num_sections * sizeof(IMAGE_SECTION_HEADER));
+ memcpy(efi_reloc, efi,
+ sizeof(*dos)
+ + sizeof(*nt)
+ + nt->FileHeader.SizeOfOptionalHeader
+ + num_sections * sizeof(IMAGE_SECTION_HEADER));
/* Load sections into RAM */
for (i = num_sections - 1; i >= 0; i--) {
(unsigned long)image_base) != EFI_SUCCESS) {
efi_free_pages((uintptr_t) efi_reloc,
(virt_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT);
- return EFI_LOAD_ERROR;
+ ret = EFI_LOAD_ERROR;
+ goto err;
}
/* Flush cache */
loaded_image_info->image_base = efi_reloc;
loaded_image_info->image_size = virt_size;
- return EFI_SUCCESS;
+ if (handle->auth_status == EFI_IMAGE_AUTH_PASSED)
+ return EFI_SUCCESS;
+ else
+ return EFI_SECURITY_VIOLATION;
+
+err:
+ return ret;
}
projects / oweals / u-boot.git / commitdiff