[PATCH v4 08/16] efi_loader: image_loader: support image authentication
Heinrich Schuchardt
xypron.glpk at gmx.de
Tue Jan 21 08:15:06 CET 2020
On 1/21/20 7:12 AM, AKASHI Takahiro wrote:
> On Fri, Jan 17, 2020 at 06:51:50AM +0100, Heinrich Schuchardt wrote:
>> On 1/17/20 6:11 AM, AKASHI Takahiro wrote:
>>> On Thu, Jan 09, 2020 at 12:55:17AM +0100, Heinrich Schuchardt wrote:
>>>> On 12/18/19 1:45 AM, AKASHI Takahiro wrote:
>>>>> With this commit, image validation can be enforced, as UEFI specification
>>>>> section 32.5 describes, if CONFIG_EFI_SECURE_BOOT is enabled.
>>>>>
>>>>> Currently we support
>>>>> * authentication based on db and dbx,
>>>>> so dbx-validated image will always be rejected.
>>>>> * following signature types:
>>>>> EFI_CERT_SHA256_GUID (SHA256 digest for unsigned images)
>>>>> EFI_CERT_X509_GUID (x509 certificate for signed images)
>>>>> Timestamp-based certificate revocation is not supported here.
>>>>>
>>>>> Internally, authentication data is stored in one of certificates tables
>>>>> of PE image (See efi_image_parse()) and will be verified by
>>>>> efi_image_authenticate() before loading a given image.
>>>>>
>>>>> It seems that UEFI specification defines the verification process
>>>>> in a bit ambiguous way. I tried to implement it as closely to as
>>>>> EDK2 does.
>>>>>
>>>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
>>>>> ---
>>>>> include/efi_loader.h | 7 +-
>>>>> lib/efi_loader/efi_boottime.c | 2 +-
>>>>> lib/efi_loader/efi_image_loader.c | 454 +++++++++++++++++++++++++++++-
>>>>> 3 files changed, 449 insertions(+), 14 deletions(-)
>>>>>
>>>>> diff --git a/include/efi_loader.h b/include/efi_loader.h
>>>>> index 1f88caf86709..e12b49098fb0 100644
>>>>> --- a/include/efi_loader.h
>>>>> +++ b/include/efi_loader.h
>>>>> @@ -11,6 +11,7 @@
>>>>> #include <common.h>
>>>>> #include <part_efi.h>
>>>>> #include <efi_api.h>
>>>>> +#include <pe.h>
>>>>>
>>>>> static inline int guidcmp(const void *g1, const void *g2)
>>>>> {
>>>>> @@ -398,7 +399,8 @@ efi_status_t efi_set_watchdog(unsigned long timeout);
>>>>> /* Called from places to check whether a timer expired */
>>>>> void efi_timer_check(void);
>>>>> /* PE loader implementation */
>>>>> -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);
>>>>> /* Called once to store the pristine gd pointer */
>>>>> void efi_save_gd(void);
>>>>> @@ -726,6 +728,9 @@ void efi_sigstore_free(struct efi_signature_store *sigstore);
>>>>> struct efi_signature_store *efi_sigstore_parse_sigdb(u16 *name);
>>>>>
>>>>> bool efi_secure_boot_enabled(void);
>>>>> +
>>>>> +bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp,
>>>>> + WIN_CERTIFICATE **auth, size_t *auth_len);
>>>>> #endif /* CONFIG_EFI_SECURE_BOOT */
>>>>>
>>>>> #else /* CONFIG_IS_ENABLED(EFI_LOADER) */
>>>>> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
>>>>> index 493d906c641d..311681764034 100644
>>>>> --- a/lib/efi_loader/efi_boottime.c
>>>>> +++ b/lib/efi_loader/efi_boottime.c
>>>>> @@ -1879,7 +1879,7 @@ efi_status_t EFIAPI efi_load_image(bool boot_policy,
>>>>> efi_dp_split_file_path(file_path, &dp, &fp);
>>>>> ret = efi_setup_loaded_image(dp, fp, image_obj, &info);
>>>>> if (ret == EFI_SUCCESS)
>>>>> - ret = efi_load_pe(*image_obj, dest_buffer, info);
>>>>> + ret = efi_load_pe(*image_obj, dest_buffer, source_size, info);
>>>>> if (!source_buffer)
>>>>> /* Release buffer to which file was loaded */
>>>>> efi_free_pages((uintptr_t)dest_buffer,
>>>>> diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
>>>>> index 13541cfa7a28..939758e61e3c 100644
>>>>> --- a/lib/efi_loader/efi_image_loader.c
>>>>> +++ b/lib/efi_loader/efi_image_loader.c
>>>>> @@ -9,7 +9,9 @@
>>>>>
>>>>> #include <common.h>
>>>>> #include <efi_loader.h>
>>>>> +#include <malloc.h>
>>>>> #include <pe.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;
>>>>> @@ -205,6 +207,367 @@ static void efi_set_code_and_data_type(
>>>>> }
>>>>> }
>>>>>
>>>>> +#ifdef CONFIG_EFI_SECURE_BOOT
>>>>> +/**
>>>>> + * efi_image_parse - parse a PE image
>>>>> + * @efi: Pointer to image
>>>>> + * @len: Size of @efi
>>>>> + * @regs: 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)
>>>>
>>>>
>>>> This function is way too long (> 100 lines). Please, cut it into logical
>>>> units.
>>>>
>>>>
>>>>
>>>>> +{
>>>>> + struct efi_image_regions *regs;
>>>>> + IMAGE_DOS_HEADER *dos;
>>>>> + IMAGE_NT_HEADERS32 *nt;
>>>>> + IMAGE_SECTION_HEADER *sections, **sorted;
>>>>> + int num_regions, num_sections, i, j;
>>>>> + 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.
>>>>> + * As we can assume that it is already ordered in most cases,
>>>>> + * the following code is optimized for this.
>>>>> + */
>>>>> + for (sorted[0] = §ions[0], i = 1; i < num_sections; i++) {
>>>>
>>>> If sections[0] is not the lowest entry this function fails.
>>>>
>>>> Please, use qsort() supplied in lib/qsort.c.
>>>
>>> I'd rather fix my code as it is much simpler than qsort.
>>
>> Using qsort will result in a smaller code size. With qsort your code
>> will also be much easier to read.
>>
>>>
>>>>> + if (sorted[i - 1]->VirtualAddress
>>>>> + <= sections[i].VirtualAddress) {
>>>>> + sorted[i] = §ions[i];
>>>>> + } else {
>>>>> + if (i == 1) {
>>>>> + sorted[1] = sorted[0];
>>>>> + sorted[0] = §ions[1];
>>>>> + continue;
>>>>> + }
>>>>> +
>>>>> + sorted[i] = sorted[i - 1];
>>>>> + for (j = i - 2; j >= 0; j--) {
>>>>> + if (!j || sorted[j]->VirtualAddress
>>>>> + <= sections[i].VirtualAddress) {
>>>>> + sorted[j + 1] = §ions[i];
>>>>> + continue;
>>>>> + } else {
>>>>> + sorted[j + 1] = sorted[j];
>>>>> + }
>>>>> + }
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + 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
>>>>> + * @len: 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 len)
>>>>> +{
>>>>> + 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;
>>>>> + bool ret = false;
>>>>> +
>>>>> + if (!efi_secure_boot_enabled())
>>>>> + return true;
>>>>> +
>>>>> + if (!efi_image_parse(efi, len, ®s, &wincerts,
>>>>> + &wincerts_len)) {
>>>>> + debug("Parsing PE executable image failed\n");
>>>>> + return false;
>>>>> + }
>>>>> +
>>>>> + if (!wincerts) {
>>>>> + /* The image is not signed */
>>>>> + ret = efi_image_unsigned_authenticate(regs);
>>>>> + free(regs);
>>>>> +
>>>>> + return ret;
>>>>> + }
>>>>> +
>>>>> + /*
>>>>> + * 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);
>>>>> +
>>>>> + return ret;
>>>>> +}
>>>>> +#else
>>>>> +static bool efi_image_authenticate(void *efi, size_t len)
>>>>> +{
>>>>> + return true;
>>>>> +}
>>>>> +#endif /* CONFIG_EFI_SECURE_BOOT */
>>>>> +
>>>>> /**
>>>>> * efi_load_pe() - relocate EFI binary
>>>>> *
>>>>> @@ -216,7 +579,8 @@ static void efi_set_code_and_data_type(
>>>>> * @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;
>>>>> @@ -231,17 +595,57 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
>>>>> uint64_t image_base;
>>>>> unsigned long virt_size = 0;
>>>>> int supported = 0;
>>>>> + void *new_efi = NULL;
>>>>> + size_t new_efi_size;
>>>>> + efi_status_t ret;
>>>>> +
>>>>> + /*
>>>>> + * 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 EFI_OUT_OF_RESOURCES;
>>>>> + memcpy(new_efi, efi, efi_size);
>>>>> + efi = new_efi;
>>>>> + efi_size = new_efi_size;
>>>>> + }
>>>>> +
>>>>> + /* 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++)
>>>>> @@ -253,14 +657,29 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
>>>>> 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)) {
>>>>> + ret = EFI_ACCESS_DENIED;
>>>>
>>>> According to the UEFI specification LoadImage() should return
>>>> EFI_SECURITY_VIOLATION in this case.
>>>
>>> Will check.
>>>
>>>> Further behaviour should depend on variables AuditMode and DeployedMode.
>>>>
>>>> If authentication fails, you must update the configuration table
>>>> identified by EFI_IMAGE_SECURITY_DATABASE_GUID containing the Image
>>>> Execution Information. If the authentication succeeds you may enter a
>>>> record.
>>>>
>>>> It seems to me that in your patch series you are not creating the
>>>> configuration table at all.
>>>
>>> >From the very beginning of my submissions, I have clearly said
>>> that this feature was *beyond the scope* in my current series.
>>> ===8<===
>>> Unsupported features: (marked as TODO in most cases in the source code,
>>> and won't be included in this series)
>>> (snip)
>>> * recording rejected images in EFI_IMAGE_EXECUTION_INFO_TABLE
>>> ===>8===
>>>
>>>> The content of the Image Execution Information Table should be used to
>>>> decide if StartImage() may start an image. This is still missing in the
>>>> patch series.
>>>
>>> No.
>>> Whether such information be in configuration table or not,
>>> non-authenticated image won't be started if secure boot is in force.
>>
>> I cannot find any such check in efi_start_image().
>
> Because my current code *rejects* any unauthenticated images being loaded
> and return no valid pointer to image handle.
> If an error code in this case is changed and efi_load_image() still returns
> a valid handle, we will also have to modify efi_start_image().
>
>> Please, provide an implementation that complies with the UEFI specification:
>>
>> "The information is used to create the Image Execution Information
>> Table, which is added to the EFI System Configuration Table and assigned
>> the GUID EFI_IMAGE_SECURITY_DATABASE_GUID."
>
> Regarding "Image Execution Information Table", Heavily disagree.
> The current UEFI code, not only mine but yours, has bunch of unimplemented
> features.
What is the point of this patch if efi_start_image() does not provide
any check?
Best regards
Heinrich
>
> -Takahiro Akashi
>
>
>> Best regards
>>
>> Heinrich
>>
>>>
>>> Thanks,
>>> -Takahiro Akashi
>>>
>>>>
>>>> Best regards
>>>>
>>>> Heinrich
>>>>
>>>>> + goto err;
>>>>> + }
>>>>> +
>>>>> + /* 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,
>>>>> @@ -279,7 +698,8 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
>>>>> 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;
>>>>> @@ -295,7 +715,8 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
>>>>> 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;
>>>>> @@ -304,13 +725,16 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
>>>>> } 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--) {
>>>>> @@ -327,7 +751,8 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
>>>>> (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 */
>>>>> @@ -340,4 +765,9 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
>>>>> loaded_image_info->image_size = virt_size;
>>>>>
>>>>> return EFI_SUCCESS;
>>>>> +
>>>>> +err:
>>>>> + free(new_efi);
>>>>> +
>>>>> + return ret;
>>>>> }
>>>>>
>>>>
>>>
>>
>
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