19020191358

Committed 02 Nov 2025 05:04PM UTC coverage: 72.222% (-0.02%) from 72.241%

Build # 19020191358

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Enhance docs for ukify and direct kernel boots (#39516)

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80.0

/src/shared/pe-binary.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <sys/stat.h>
#include <unistd.h>

#include "alloc-util.h"
#include "hexdecoct.h"
#include "log.h"
#include "pe-binary.h"
#include "sort-util.h"
#include "stat-util.h"
#include "string-table.h"
#include "string-util.h"

bool pe_header_is_64bit(const PeHeader *h) {
        assert(h);

        if (le16toh(h->optional.Magic) == UINT16_C(0x010B)) /* PE32 */
                return false;

        if (le16toh(h->optional.Magic) == UINT16_C(0x020B)) /* PE32+ */
                return true;

        assert_not_reached();
}

static size_t pe_header_size(const PeHeader *pe_header) {
        assert(pe_header);

        return offsetof(PeHeader, optional) + le16toh(pe_header->pe.SizeOfOptionalHeader);
}

const IMAGE_DATA_DIRECTORY* pe_header_get_data_directory(
                const PeHeader *h,
                size_t i) {

        assert(h);

        if (i >= le32toh(PE_HEADER_OPTIONAL_FIELD(h, NumberOfRvaAndSizes)))
                return NULL;

        return PE_HEADER_OPTIONAL_FIELD(h, DataDirectory) + i;
}

const IMAGE_SECTION_HEADER* pe_section_table_find(
                const IMAGE_SECTION_HEADER *sections,
                size_t n_sections,
                const char *name) {

        size_t n;

        assert(name);
        assert(sections || n_sections == 0);

        n = strlen(name);
        if (n > sizeof(sections[0].Name)) /* Too long? */
                return NULL;

        FOREACH_ARRAY(section, sections, n_sections)
                if (memcmp(section->Name, name, n) == 0 &&
                    (n == sizeof(sections[0].Name) || memeqzero(section->Name + n, sizeof(section->Name) - n)))
                        return section;

        return NULL;
}

const IMAGE_SECTION_HEADER* pe_header_find_section(
                const PeHeader *pe_header,
                const IMAGE_SECTION_HEADER *sections,
                const char *name) {

        assert(pe_header);

        return pe_section_table_find(sections, le16toh(pe_header->pe.NumberOfSections), name);
}

int pe_load_headers(
                int fd,
                IMAGE_DOS_HEADER **ret_dos_header,
                PeHeader **ret_pe_header) {

        _cleanup_free_ IMAGE_DOS_HEADER *dos_header = NULL;
        _cleanup_free_ PeHeader *pe_header = NULL;
        ssize_t n;

        assert(fd >= 0);

        dos_header = new(IMAGE_DOS_HEADER, 1);
        if (!dos_header)
                return log_oom_debug();

        n = pread(fd,
                  dos_header,
                  sizeof(IMAGE_DOS_HEADER),
                  0);
        if (n < 0)
                return log_debug_errno(errno, "Failed to read DOS header: %m");
        if ((size_t) n != sizeof(IMAGE_DOS_HEADER))
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while reading MZ executable header.");

        if (le16toh(dos_header->e_magic) != UINT16_C(0x5A4D))
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "File lacks MZ executable header.");

        pe_header = new(PeHeader, 1);
        if (!pe_header)
                return log_oom_debug();

        n = pread(fd,
                  pe_header,
                  offsetof(PeHeader, optional),
                  le32toh(dos_header->e_lfanew));
        if (n < 0)
                return log_debug_errno(errno, "Failed to read PE executable header: %m");
        if ((size_t) n != offsetof(PeHeader, optional))
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while reading PE executable header.");

        if (le32toh(pe_header->signature) != UINT32_C(0x00004550))
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "File lacks PE executable header.");

        if (le16toh(pe_header->pe.SizeOfOptionalHeader) < sizeof_field(PeHeader, optional.Magic))
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Optional header size too short for magic.");

        PeHeader *pe_header_tmp = realloc(pe_header, MAX(sizeof(PeHeader), pe_header_size(pe_header)));
        if (!pe_header_tmp)
                return log_oom_debug();
        pe_header = pe_header_tmp;

        n = pread(fd,
                  &pe_header->optional,
                  le16toh(pe_header->pe.SizeOfOptionalHeader),
                  le32toh(dos_header->e_lfanew) + offsetof(PeHeader, optional));
        if (n < 0)
                return log_debug_errno(errno, "Failed to read PE executable optional header: %m");
        if ((size_t) n != le16toh(pe_header->pe.SizeOfOptionalHeader))
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while reading PE executable optional header.");

        if (!IN_SET(le16toh(pe_header->optional.Magic), UINT16_C(0x010B), UINT16_C(0x020B)))
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Optional header magic invalid.");

        if (pe_header_size(pe_header) !=
            PE_HEADER_OPTIONAL_FIELD_OFFSET(pe_header, DataDirectory) +
            sizeof(IMAGE_DATA_DIRECTORY) * (uint64_t) le32toh(PE_HEADER_OPTIONAL_FIELD(pe_header, NumberOfRvaAndSizes)))
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Optional header size mismatch.");

        if (ret_dos_header)
                *ret_dos_header = TAKE_PTR(dos_header);
        if (ret_pe_header)
                *ret_pe_header = TAKE_PTR(pe_header);

        return 0;
}

int pe_load_sections(
                int fd,
                const IMAGE_DOS_HEADER *dos_header,
                const PeHeader *pe_header,
                IMAGE_SECTION_HEADER **ret_sections) {

        _cleanup_free_ IMAGE_SECTION_HEADER *sections = NULL;
        size_t nos;
        ssize_t n;

        assert(fd >= 0);
        assert(dos_header);
        assert(pe_header);

        nos = le16toh(pe_header->pe.NumberOfSections);

        sections = new(IMAGE_SECTION_HEADER, nos);
        if (!sections)
                return log_oom_debug();

        n = pread(fd,
                  sections,
                  sizeof(IMAGE_SECTION_HEADER) * nos,
                  le32toh(dos_header->e_lfanew) + pe_header_size(pe_header));
        if (n < 0)
                return log_debug_errno(errno, "Failed to read section table: %m");
        if ((size_t) n != sizeof(IMAGE_SECTION_HEADER) * nos)
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while reading section table.");

        if (ret_sections)
                *ret_sections = TAKE_PTR(sections);

        return 0;
}

int pe_read_section_data(
                int fd,
                const IMAGE_SECTION_HEADER *section,
                size_t max_size,
                void **ret,
                size_t *ret_size) {

        assert(fd >= 0);
        assert(section);

        size_t n = le32toh(section->VirtualSize);
        if (n > MIN(max_size, (size_t) SSIZE_MAX))
                return -E2BIG;

        _cleanup_free_ void *data = malloc(n+1);
        if (!data)
                return -ENOMEM;

        ssize_t ss = pread(fd, data, n, le32toh(section->PointerToRawData));
        if (ss < 0)
                return -errno;
        if ((size_t) ss != n)
                return -EIO;

        if (ret_size)
                *ret_size = n;
        else {
                /* Check that there are no embedded NUL bytes if the caller doesn't want to know the size
                 * (i.e. treats the blob as a string) */
                const char *nul;

                nul = memchr(data, 0, n);
                if (nul && !memeqzero(nul, n - (nul - (const char*) data))) /* If there's a NUL it must only be NULs from there on */
                        return -EBADMSG;
        }
        if (ret) {
                ((uint8_t*) data)[n] = 0; /* NUL terminate, no matter what */
                *ret = TAKE_PTR(data);
        }

        return 0;
}

int pe_read_section_data_by_name(
                int fd,
                const PeHeader *pe_header,
                const IMAGE_SECTION_HEADER *sections,
                const char *name,
                size_t max_size,
                void **ret,
                size_t *ret_size) {

        const IMAGE_SECTION_HEADER *section;

        assert(fd >= 0);
        assert(pe_header);
        assert(sections || pe_header->pe.NumberOfSections == 0);
        assert(name);

        section = pe_header_find_section(pe_header, sections, name);
        if (!section)
                return -ENXIO;

        return pe_read_section_data(fd, section, max_size, ret, ret_size);
}

bool pe_is_uki(const PeHeader *pe_header, const IMAGE_SECTION_HEADER *sections) {
        assert(pe_header);
        assert(sections || le16toh(pe_header->pe.NumberOfSections) == 0);

        if (le16toh(pe_header->optional.Subsystem) != IMAGE_SUBSYSTEM_EFI_APPLICATION)
                return false;

        /* Note that the UKI spec only requires .linux, but we are stricter here, and require .osrel too,
         * since for sd-boot it just doesn't make sense to not have that. */
        return
                pe_header_find_section(pe_header, sections, ".osrel") &&
                pe_header_find_section(pe_header, sections, ".linux");
}

bool pe_is_addon(const PeHeader *pe_header, const IMAGE_SECTION_HEADER *sections) {
        assert(pe_header);
        assert(sections || le16toh(pe_header->pe.NumberOfSections) == 0);

        if (le16toh(pe_header->optional.Subsystem) != IMAGE_SUBSYSTEM_EFI_APPLICATION)
                return false;

        /* Add-ons do not have a Linux kernel, but do have one of .cmdline, .dtb, .initrd or .ucode (currently) */
        return !pe_header_find_section(pe_header, sections, ".linux") &&
                (pe_header_find_section(pe_header, sections, ".cmdline") ||
                 pe_header_find_section(pe_header, sections, ".dtb") ||
                 pe_header_find_section(pe_header, sections, ".initrd") ||
                 pe_header_find_section(pe_header, sections, ".ucode"));
}

bool pe_is_native(const PeHeader *pe_header) {
        assert(pe_header);

#ifdef _IMAGE_FILE_MACHINE_NATIVE
        return le16toh(pe_header->pe.Machine) == _IMAGE_FILE_MACHINE_NATIVE;
#else
        return false;
#endif
}

int pe_is_native_fd(int fd) {
        _cleanup_free_ PeHeader *pe_header = NULL;
        int r;

        r = pe_load_headers(fd, /* ret_dos_header= */ NULL, &pe_header);
        if (r < 0)
                return r;

        return pe_is_native(pe_header);
}

/* Implements:
 *
 * https://download.microsoft.com/download/9/c/5/9c5b2167-8017-4bae-9fde-d599bac8184a/authenticode_pe.docx
 * → Section "Calculating the PE Image Hash"
 */

#if HAVE_OPENSSL
static int hash_file(int fd, EVP_MD_CTX *md_ctx, uint64_t offset, uint64_t size) {
        uint8_t buffer[64*1024];

        log_debug("Hashing %" PRIu64 " @ %" PRIu64 " → %" PRIu64, size, offset, offset + size);

        while (size > 0) {
                size_t m = MIN(size, sizeof(buffer));
                ssize_t n;

                n = pread(fd, buffer, m, offset);
                if (n < 0)
                        return log_debug_errno(errno, "Failed to read file for hashing: %m");
                if ((size_t) n != m)
                        return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while hashing.");

                if (EVP_DigestUpdate(md_ctx, buffer, m) != 1)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Unable to hash data.");

                offset += m;
                size -= m;
        }

        return 0;
}

static int section_offset_cmp(const IMAGE_SECTION_HEADER *a, const IMAGE_SECTION_HEADER *b) {
        return CMP(ASSERT_PTR(a)->PointerToRawData, ASSERT_PTR(b)->PointerToRawData);
}

int pe_hash(int fd,
            const EVP_MD *md,
            void **ret_hash,
            size_t *ret_hash_size) {

        _cleanup_(EVP_MD_CTX_freep) EVP_MD_CTX *mdctx = NULL;
        _cleanup_free_ IMAGE_SECTION_HEADER *sections = NULL;
        _cleanup_free_ IMAGE_DOS_HEADER *dos_header = NULL;
        _cleanup_free_ PeHeader *pe_header = NULL;
        const IMAGE_DATA_DIRECTORY *certificate_table;
        struct stat st;
        uint64_t p, q;
        int r;

        assert(fd >= 0);
        assert(md);
        assert(ret_hash_size);
        assert(ret_hash);

        if (fstat(fd, &st) < 0)
                return log_debug_errno(errno, "Failed to stat file: %m");
        r = stat_verify_regular(&st);
        if (r < 0)
                return log_debug_errno(r, "Not a regular file: %m");

        r = pe_load_headers(fd, &dos_header, &pe_header);
        if (r < 0)
                return r;

        r = pe_load_sections(fd, dos_header, pe_header, &sections);
        if (r < 0)
                return r;

        certificate_table = pe_header_get_data_directory(pe_header, IMAGE_DATA_DIRECTORY_INDEX_CERTIFICATION_TABLE);
        if (!certificate_table)
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "File lacks certificate table.");

        mdctx = EVP_MD_CTX_new();
        if (!mdctx)
                return log_oom_debug();

        if (EVP_DigestInit_ex(mdctx, md, NULL) != 1)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to allocate message digest.");

        /* Everything from beginning of file to CheckSum field in PE header */
        p = (uint64_t) dos_header->e_lfanew +
                offsetof(PeHeader, optional.CheckSum);
        r = hash_file(fd, mdctx, 0, p);
        if (r < 0)
                return r;
        p += sizeof(le32_t);

        /* Everything between the CheckSum field and the Image Data Directory Entry for the Certification Table */
        q = (uint64_t) dos_header->e_lfanew +
                PE_HEADER_OPTIONAL_FIELD_OFFSET(pe_header, DataDirectory[IMAGE_DATA_DIRECTORY_INDEX_CERTIFICATION_TABLE]);
        r = hash_file(fd, mdctx, p, q - p);
        if (r < 0)
                return r;
        q += sizeof(IMAGE_DATA_DIRECTORY);

        /* The rest of the header + the section table */
        p = pe_header->optional.SizeOfHeaders;
        if (p < q)
                return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "SizeOfHeaders too short.");
        r = hash_file(fd, mdctx, q, p - q);
        if (r < 0)
                return r;

        /* Sort by location in file */
        typesafe_qsort(sections, pe_header->pe.NumberOfSections, section_offset_cmp);

        FOREACH_ARRAY(section, sections, pe_header->pe.NumberOfSections) {
                r = hash_file(fd, mdctx, section->PointerToRawData, section->SizeOfRawData);
                if (r < 0)
                        return r;

                p += section->SizeOfRawData;
        }

        if ((uint64_t) st.st_size > p) {

                if (st.st_size - p < certificate_table->Size)
                        return log_debug_errno(errno, "No space for certificate table, refusing.");

                r = hash_file(fd, mdctx, p, st.st_size - p - certificate_table->Size);
                if (r < 0)
                        return r;

                /* If the file size is not a multiple of 8 bytes, pad the hash with zero bytes. */
                if (st.st_size % 8 != 0 && EVP_DigestUpdate(mdctx, (const uint8_t[8]) {}, 8 - (st.st_size % 8)) != 1)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Unable to hash data.");
        }

        int hsz = EVP_MD_CTX_size(mdctx);
        if (hsz < 0)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to get hash size.");

        unsigned hash_size = (unsigned) hsz;
        _cleanup_free_ void *hash = malloc(hsz);
        if (!hash)
                return log_oom_debug();

        if (EVP_DigestFinal_ex(mdctx, hash, &hash_size) != 1)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to finalize hash function.");

        assert(hash_size == (unsigned) hsz);

        *ret_hash = TAKE_PTR(hash);
        *ret_hash_size = hash_size;

        return 0;
}

int pe_checksum(int fd, uint32_t *ret) {
        _cleanup_free_ IMAGE_DOS_HEADER *dos_header = NULL;
        _cleanup_free_ PeHeader *pe_header = NULL;
        struct stat st;
        int r;

        assert(fd >= 0);
        assert(ret);

        if (fstat(fd, &st) < 0)
                return log_debug_errno(errno, "Failed to stat file: %m");

        r = pe_load_headers(fd, &dos_header, &pe_header);
        if (r < 0)
                return r;

        uint32_t checksum = 0, checksum_offset = le32toh(dos_header->e_lfanew) + offsetof(PeHeader, optional.CheckSum);
        size_t off = 0;
        for (;;) {
                uint16_t buf[32*1024];

                ssize_t n = pread(fd, buf, sizeof(buf), off);
                if (n == 0)
                        break;
                if (n < 0)
                        return log_debug_errno(errno, "Failed to read from PE file: %m");
                if (n % sizeof(uint16_t) != 0)
                        return log_debug_errno(SYNTHETIC_ERRNO(EIO), "Short read from PE file");

                for (size_t i = 0; i < (size_t) n / 2; i++) {
                        if (off + i >= checksum_offset && off + i < checksum_offset + sizeof(pe_header->optional.CheckSum))
                                continue;

                        uint16_t val = le16toh(buf[i]);

                        checksum += val;
                        checksum = (checksum >> 16) + (checksum & 0xffff);
                }

                off += n;
        }

        checksum = (checksum >> 16) + (checksum & 0xffff);
        checksum += off;

        *ret = checksum;
        return 0;
}

typedef void* SectionHashArray[_UNIFIED_SECTION_MAX];

static void section_hash_array_done(SectionHashArray *array) {
        assert(array);

        for (size_t i = 0; i < _UNIFIED_SECTION_MAX; i++)
                free((*array)[i]);
}

int uki_hash(int fd,
             const EVP_MD *md,
             void* ret_hashes[static _UNIFIED_SECTION_MAX],
             size_t *ret_hash_size) {

        _cleanup_(section_hash_array_done) SectionHashArray hashes = {};
        _cleanup_free_ IMAGE_SECTION_HEADER *sections = NULL;
        _cleanup_free_ IMAGE_DOS_HEADER *dos_header = NULL;
        _cleanup_free_ PeHeader *pe_header = NULL;
        int r;

        assert(fd >= 0);
        assert(ret_hashes);
        assert(ret_hash_size);

        r = pe_load_headers(fd, &dos_header, &pe_header);
        if (r < 0)
                return r;

        r = pe_load_sections(fd, dos_header, pe_header, &sections);
        if (r < 0)
                return r;

        int hsz = EVP_MD_size(md);
        if (hsz < 0)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to get hash size.");

        FOREACH_ARRAY(section, sections, pe_header->pe.NumberOfSections) {
                _cleanup_(EVP_MD_CTX_freep) EVP_MD_CTX *mdctx = NULL;
                _cleanup_free_ char *n = NULL;
                ssize_t i;

                n = memdup_suffix0(section->Name, sizeof(section->Name));
                if (!n)
                        return log_oom_debug();

                i = string_table_lookup_from_string(unified_sections, _UNIFIED_SECTION_MAX, n);
                if (i < 0)
                        continue;

                if (hashes[i])
                        return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Duplicate section");

                mdctx = EVP_MD_CTX_new();
                if (!mdctx)
                        return log_oom_debug();

                if (EVP_DigestInit_ex(mdctx, md, NULL) != 1)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to allocate message digest.");

                r = hash_file(fd, mdctx, section->PointerToRawData, MIN(section->VirtualSize, section->SizeOfRawData));
                if (r < 0)
                        return r;

                if (section->SizeOfRawData < section->VirtualSize) {
                        uint8_t zeroes[1024] = {};
                        size_t remaining = section->VirtualSize - section->SizeOfRawData;

                        while (remaining > 0) {
                                size_t sz = MIN(sizeof(zeroes), remaining);

                                if (EVP_DigestUpdate(mdctx, zeroes, sz) != 1)
                                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Unable to hash data.");

                                remaining -= sz;
                        }
                }

                hashes[i] = malloc(hsz);
                if (!hashes[i])
                        return log_oom_debug();

                unsigned hash_size = (unsigned) hsz;
                if (EVP_DigestFinal_ex(mdctx, hashes[i], &hash_size) != 1)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to finalize hash function.");

                assert(hash_size == (unsigned) hsz);

                if (DEBUG_LOGGING) {
                        _cleanup_free_ char *hs = NULL;

                        hs = hexmem(hashes[i], hsz);
                        log_debug("Section %s with %s is %s.", n, EVP_MD_name(md), strna(hs));
                }
        }

        memcpy(ret_hashes, hashes, sizeof(hashes));
        zero(hashes);
        *ret_hash_size = (unsigned) hsz;

        return 0;
}
#endif

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <sys/stat.h>
4	#include <unistd.h>
5
6	#include "alloc-util.h"
7	#include "hexdecoct.h"
8	#include "log.h"
9	#include "pe-binary.h"
10	#include "sort-util.h"
11	#include "stat-util.h"
12	#include "string-table.h"
13	#include "string-util.h"
14
15	bool pe_header_is_64bit(const PeHeader *h) {	605✔
16	assert(h);	605✔
17
18	if (le16toh(h->optional.Magic) == UINT16_C(0x010B)) /* PE32 */	605✔
19	return false;
20
21	if (le16toh(h->optional.Magic) == UINT16_C(0x020B)) /* PE32+ */	333✔
22	return true;
23
24	assert_not_reached();	×
25	}
26
27	static size_t pe_header_size(const PeHeader *pe_header) {	649✔
28	assert(pe_header);	649✔
29
30	return offsetof(PeHeader, optional) + le16toh(pe_header->pe.SizeOfOptionalHeader);	649✔
31	}
32
33	const IMAGE_DATA_DIRECTORY* pe_header_get_data_directory(	23✔
34	const PeHeader *h,
35	size_t i) {
36
37	assert(h);	23✔
38
39	if (i >= le32toh(PE_HEADER_OPTIONAL_FIELD(h, NumberOfRvaAndSizes)))	23✔
40	return NULL;
41
42	return PE_HEADER_OPTIONAL_FIELD(h, DataDirectory) + i;	23✔
43	}
44
45	const IMAGE_SECTION_HEADER* pe_section_table_find(	680✔
46	const IMAGE_SECTION_HEADER *sections,
47	size_t n_sections,
48	const char *name) {
49
50	size_t n;	680✔
51
52	assert(name);	680✔
53	assert(sections \|\| n_sections == 0);	680✔
54
55	n = strlen(name);	680✔
56	if (n > sizeof(sections[0].Name)) /* Too long? */	680✔
57	return NULL;
58
59	FOREACH_ARRAY(section, sections, n_sections)	4,199✔
60	if (memcmp(section->Name, name, n) == 0 &&	4,080✔
61	(n == sizeof(sections[0].Name) \|\| memeqzero(section->Name + n, sizeof(section->Name) - n)))	187✔
62	return section;	561✔
63
64	return NULL;
65	}
66
67	const IMAGE_SECTION_HEADER* pe_header_find_section(	170✔
68	const PeHeader *pe_header,
69	const IMAGE_SECTION_HEADER *sections,
70	const char *name) {
71
72	assert(pe_header);	170✔
73
74	return pe_section_table_find(sections, le16toh(pe_header->pe.NumberOfSections), name);	170✔
75	}
76
77	int pe_load_headers(	270✔
78	int fd,
79	IMAGE_DOS_HEADER **ret_dos_header,
80	PeHeader **ret_pe_header) {
81
82	_cleanup_free_ IMAGE_DOS_HEADER *dos_header = NULL;	540✔
83	_cleanup_free_ PeHeader *pe_header = NULL;	270✔
84	ssize_t n;	270✔
85
86	assert(fd >= 0);	270✔
87
88	dos_header = new(IMAGE_DOS_HEADER, 1);	270✔
89	if (!dos_header)	270✔
90	return log_oom_debug();	×
91
92	n = pread(fd,	270✔
93	dos_header,
94	sizeof(IMAGE_DOS_HEADER),
95	0);
96	if (n < 0)	270✔
97	return log_debug_errno(errno, "Failed to read DOS header: %m");	×
98	if ((size_t) n != sizeof(IMAGE_DOS_HEADER))	270✔
99	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while reading MZ executable header.");	×
100
101	if (le16toh(dos_header->e_magic) != UINT16_C(0x5A4D))	270✔
102	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "File lacks MZ executable header.");	2✔
103
104	pe_header = new(PeHeader, 1);	268✔
105	if (!pe_header)	268✔
106	return log_oom_debug();	×
107
108	n = pread(fd,	536✔
109	pe_header,
110	offsetof(PeHeader, optional),
111	le32toh(dos_header->e_lfanew));	268✔
112	if (n < 0)	268✔
113	return log_debug_errno(errno, "Failed to read PE executable header: %m");	×
114	if ((size_t) n != offsetof(PeHeader, optional))	268✔
115	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while reading PE executable header.");	×
116
117	if (le32toh(pe_header->signature) != UINT32_C(0x00004550))	268✔
118	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "File lacks PE executable header.");	×
119
120	if (le16toh(pe_header->pe.SizeOfOptionalHeader) < sizeof_field(PeHeader, optional.Magic))	268✔
121	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Optional header size too short for magic.");	×
122
123	PeHeader *pe_header_tmp = realloc(pe_header, MAX(sizeof(PeHeader), pe_header_size(pe_header)));	268✔
124	if (!pe_header_tmp)	268✔
125	return log_oom_debug();	×
126	pe_header = pe_header_tmp;	268✔
127
128	n = pread(fd,	536✔
129	&pe_header->optional,	268✔
130	le16toh(pe_header->pe.SizeOfOptionalHeader),	268✔
131	le32toh(dos_header->e_lfanew) + offsetof(PeHeader, optional));	268✔
132	if (n < 0)	268✔
133	return log_debug_errno(errno, "Failed to read PE executable optional header: %m");	×
134	if ((size_t) n != le16toh(pe_header->pe.SizeOfOptionalHeader))	268✔
135	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while reading PE executable optional header.");	×
136
137	if (!IN_SET(le16toh(pe_header->optional.Magic), UINT16_C(0x010B), UINT16_C(0x020B)))	268✔
138	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Optional header magic invalid.");	×
139
140	if (pe_header_size(pe_header) !=	268✔
141	PE_HEADER_OPTIONAL_FIELD_OFFSET(pe_header, DataDirectory) +	268✔
142	sizeof(IMAGE_DATA_DIRECTORY) * (uint64_t) le32toh(PE_HEADER_OPTIONAL_FIELD(pe_header, NumberOfRvaAndSizes)))	268✔
143	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Optional header size mismatch.");	×
144
145	if (ret_dos_header)	268✔
146	*ret_dos_header = TAKE_PTR(dos_header);	119✔
147	if (ret_pe_header)	268✔
148	*ret_pe_header = TAKE_PTR(pe_header);	268✔
149
150	return 0;
151	}
152
153	int pe_load_sections(	113✔
154	int fd,
155	const IMAGE_DOS_HEADER *dos_header,
156	const PeHeader *pe_header,
157	IMAGE_SECTION_HEADER **ret_sections) {
158
159	_cleanup_free_ IMAGE_SECTION_HEADER *sections = NULL;	113✔
160	size_t nos;	113✔
161	ssize_t n;	113✔
162
163	assert(fd >= 0);	113✔
164	assert(dos_header);	113✔
165	assert(pe_header);	113✔
166
167	nos = le16toh(pe_header->pe.NumberOfSections);	113✔
168
169	sections = new(IMAGE_SECTION_HEADER, nos);	113✔
170	if (!sections)	113✔
171	return log_oom_debug();	×
172
173	n = pread(fd,	339✔
174	sections,
175	sizeof(IMAGE_SECTION_HEADER) * nos,	113✔
176	le32toh(dos_header->e_lfanew) + pe_header_size(pe_header));	113✔
177	if (n < 0)	113✔
178	return log_debug_errno(errno, "Failed to read section table: %m");	×
179	if ((size_t) n != sizeof(IMAGE_SECTION_HEADER) * nos)	113✔
180	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while reading section table.");	×
181
182	if (ret_sections)	113✔
183	*ret_sections = TAKE_PTR(sections);	113✔
184
185	return 0;
186	}
187
188	int pe_read_section_data(	170✔
189	int fd,
190	const IMAGE_SECTION_HEADER *section,
191	size_t max_size,
192	void **ret,
193	size_t *ret_size) {
194
195	assert(fd >= 0);	170✔
196	assert(section);	170✔
197
198	size_t n = le32toh(section->VirtualSize);	170✔
199	if (n > MIN(max_size, (size_t) SSIZE_MAX))	170✔
200	return -E2BIG;	170✔
201
202	_cleanup_free_ void *data = malloc(n+1);	170✔
203	if (!data)	170✔
204	return -ENOMEM;
205
206	ssize_t ss = pread(fd, data, n, le32toh(section->PointerToRawData));	170✔
207	if (ss < 0)	170✔
208	return -errno;	×
209	if ((size_t) ss != n)	170✔
210	return -EIO;
211
212	if (ret_size)	170✔
213	*ret_size = n;	×
214	else {
215	/* Check that there are no embedded NUL bytes if the caller doesn't want to know the size
216	* (i.e. treats the blob as a string) */
217	const char *nul;	170✔
218
219	nul = memchr(data, 0, n);	170✔
220	if (nul && !memeqzero(nul, n - (nul - (const char) data))) / If there's a NUL it must only be NULs from there on */	170✔
221	return -EBADMSG;
222	}
223	if (ret) {	170✔
224	((uint8_t) data)[n] = 0; / NUL terminate, no matter what */	170✔
225	*ret = TAKE_PTR(data);	170✔
226	}
227
228	return 0;
229	}
230
231	int pe_read_section_data_by_name(	×
232	int fd,
233	const PeHeader *pe_header,
234	const IMAGE_SECTION_HEADER *sections,
235	const char *name,
236	size_t max_size,
237	void **ret,
238	size_t *ret_size) {
239
240	const IMAGE_SECTION_HEADER *section;	×
241
242	assert(fd >= 0);	×
243	assert(pe_header);	×
244	assert(sections \|\| pe_header->pe.NumberOfSections == 0);	×
245	assert(name);	×
246
247	section = pe_header_find_section(pe_header, sections, name);	×
248	if (!section)	×
249	return -ENXIO;
250
251	return pe_read_section_data(fd, section, max_size, ret, ret_size);	×
252	}
253
254	bool pe_is_uki(const PeHeader pe_header, const IMAGE_SECTION_HEADER sections) {	68✔
255	assert(pe_header);	68✔
256	assert(sections \|\| le16toh(pe_header->pe.NumberOfSections) == 0);	68✔
257
258	if (le16toh(pe_header->optional.Subsystem) != IMAGE_SUBSYSTEM_EFI_APPLICATION)	68✔
259	return false;
260
261	/* Note that the UKI spec only requires .linux, but we are stricter here, and require .osrel too,
262	* since for sd-boot it just doesn't make sense to not have that. */
263	return	68✔
264	pe_header_find_section(pe_header, sections, ".osrel") &&	136✔
265	pe_header_find_section(pe_header, sections, ".linux");	68✔
266	}
267
268	bool pe_is_addon(const PeHeader pe_header, const IMAGE_SECTION_HEADER sections) {	17✔
269	assert(pe_header);	17✔
270	assert(sections \|\| le16toh(pe_header->pe.NumberOfSections) == 0);	17✔
271
272	if (le16toh(pe_header->optional.Subsystem) != IMAGE_SUBSYSTEM_EFI_APPLICATION)	17✔
273	return false;
274
275	/* Add-ons do not have a Linux kernel, but do have one of .cmdline, .dtb, .initrd or .ucode (currently) */
276	return !pe_header_find_section(pe_header, sections, ".linux") &&	34✔
277	(pe_header_find_section(pe_header, sections, ".cmdline") \|\|	17✔
278	pe_header_find_section(pe_header, sections, ".dtb") \|\|	×
279	pe_header_find_section(pe_header, sections, ".initrd") \|\|	×
280	pe_header_find_section(pe_header, sections, ".ucode"));	×
281	}
282
283	bool pe_is_native(const PeHeader *pe_header) {	234✔
284	assert(pe_header);	234✔
285
286	#ifdef _IMAGE_FILE_MACHINE_NATIVE
287	return le16toh(pe_header->pe.Machine) == _IMAGE_FILE_MACHINE_NATIVE;	234✔
288	#else
289	return false;
290	#endif
291	}
292
293	int pe_is_native_fd(int fd) {	149✔
294	_cleanup_free_ PeHeader *pe_header = NULL;	149✔
295	int r;	149✔
296
297	r = pe_load_headers(fd, /* ret_dos_header= */ NULL, &pe_header);	149✔
298	if (r < 0)	149✔
299	return r;
300
301	return pe_is_native(pe_header);	149✔
302	}
303
304	/* Implements:
305	*
306	* https://download.microsoft.com/download/9/c/5/9c5b2167-8017-4bae-9fde-d599bac8184a/authenticode_pe.docx
307	* → Section "Calculating the PE Image Hash"
308	*/
309
310	#if HAVE_OPENSSL
311	static int hash_file(int fd, EVP_MD_CTX *md_ctx, uint64_t offset, uint64_t size) {	217✔
312	uint8_t buffer[64*1024];	217✔
313
314	log_debug("Hashing %" PRIu64 " @ %" PRIu64 " → %" PRIu64, size, offset, offset + size);	217✔
315
316	while (size > 0) {	453✔
317	size_t m = MIN(size, sizeof(buffer));	236✔
318	ssize_t n;	236✔
319
320	n = pread(fd, buffer, m, offset);	236✔
321	if (n < 0)	236✔
322	return log_debug_errno(errno, "Failed to read file for hashing: %m");	×
323	if ((size_t) n != m)	236✔
324	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Short read while hashing.");	×
325
326	if (EVP_DigestUpdate(md_ctx, buffer, m) != 1)	236✔
327	return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Unable to hash data.");	×
328
329	offset += m;	236✔
330	size -= m;	236✔
331	}
332
333	return 0;
334	}
335
336	static int section_offset_cmp(const IMAGE_SECTION_HEADER a, const IMAGE_SECTION_HEADER b) {	180✔
337	return CMP(ASSERT_PTR(a)->PointerToRawData, ASSERT_PTR(b)->PointerToRawData);	180✔
338	}
339
340	int pe_hash(int fd,	24✔
341	const EVP_MD *md,
342	void **ret_hash,
343	size_t *ret_hash_size) {
344
345	_cleanup_(EVP_MD_CTX_freep) EVP_MD_CTX *mdctx = NULL;	24✔
346	_cleanup_free_ IMAGE_SECTION_HEADER *sections = NULL;	×
347	_cleanup_free_ IMAGE_DOS_HEADER *dos_header = NULL;	×
348	_cleanup_free_ PeHeader *pe_header = NULL;	24✔
349	const IMAGE_DATA_DIRECTORY *certificate_table;	24✔
350	struct stat st;	24✔
351	uint64_t p, q;	24✔
352	int r;	24✔
353
354	assert(fd >= 0);	24✔
355	assert(md);	24✔
356	assert(ret_hash_size);	24✔
357	assert(ret_hash);	24✔
358
359	if (fstat(fd, &st) < 0)	24✔
360	return log_debug_errno(errno, "Failed to stat file: %m");	×
361	r = stat_verify_regular(&st);	24✔
362	if (r < 0)	24✔
363	return log_debug_errno(r, "Not a regular file: %m");	2✔
364
365	r = pe_load_headers(fd, &dos_header, &pe_header);	22✔
366	if (r < 0)	22✔
367	return r;
368
369	r = pe_load_sections(fd, dos_header, pe_header, &sections);	20✔
370	if (r < 0)	20✔
371	return r;
372
373	certificate_table = pe_header_get_data_directory(pe_header, IMAGE_DATA_DIRECTORY_INDEX_CERTIFICATION_TABLE);	20✔
374	if (!certificate_table)	20✔
375	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "File lacks certificate table.");	×
376
377	mdctx = EVP_MD_CTX_new();	20✔
378	if (!mdctx)	20✔
379	return log_oom_debug();	×
380
381	if (EVP_DigestInit_ex(mdctx, md, NULL) != 1)	20✔
382	return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to allocate message digest.");	×
383
384	/* Everything from beginning of file to CheckSum field in PE header */
385	p = (uint64_t) dos_header->e_lfanew +	20✔
386	offsetof(PeHeader, optional.CheckSum);
387	r = hash_file(fd, mdctx, 0, p);	20✔
388	if (r < 0)	20✔
389	return r;
390	p += sizeof(le32_t);	20✔
391
392	/* Everything between the CheckSum field and the Image Data Directory Entry for the Certification Table */
393	q = (uint64_t) dos_header->e_lfanew +	40✔
394	PE_HEADER_OPTIONAL_FIELD_OFFSET(pe_header, DataDirectory[IMAGE_DATA_DIRECTORY_INDEX_CERTIFICATION_TABLE]);	20✔
395	r = hash_file(fd, mdctx, p, q - p);	20✔
396	if (r < 0)	20✔
397	return r;
398	q += sizeof(IMAGE_DATA_DIRECTORY);	20✔
399
400	/* The rest of the header + the section table */
401	p = pe_header->optional.SizeOfHeaders;	20✔
402	if (p < q)	20✔
403	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "SizeOfHeaders too short.");	×
404	r = hash_file(fd, mdctx, q, p - q);	20✔
405	if (r < 0)	20✔
406	return r;
407
408	/* Sort by location in file */
409	typesafe_qsort(sections, pe_header->pe.NumberOfSections, section_offset_cmp);	20✔
410
411	FOREACH_ARRAY(section, sections, pe_header->pe.NumberOfSections) {	160✔
412	r = hash_file(fd, mdctx, section->PointerToRawData, section->SizeOfRawData);	140✔
413	if (r < 0)	140✔
414	return r;
415
416	p += section->SizeOfRawData;	140✔
417	}
418
419	if ((uint64_t) st.st_size > p) {	20✔
420
421	if (st.st_size - p < certificate_table->Size)	1✔
422	return log_debug_errno(errno, "No space for certificate table, refusing.");	×
423
424	r = hash_file(fd, mdctx, p, st.st_size - p - certificate_table->Size);	1✔
425	if (r < 0)	1✔
426	return r;
427
428	/* If the file size is not a multiple of 8 bytes, pad the hash with zero bytes. */
429	if (st.st_size % 8 != 0 && EVP_DigestUpdate(mdctx, (const uint8_t[8]) {}, 8 - (st.st_size % 8)) != 1)	1✔
430	return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Unable to hash data.");	×
431	}
432
433	int hsz = EVP_MD_CTX_size(mdctx);	20✔
434	if (hsz < 0)	20✔
435	return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to get hash size.");	×
436
437	unsigned hash_size = (unsigned) hsz;	20✔
438	_cleanup_free_ void *hash = malloc(hsz);	20✔
439	if (!hash)	20✔
440	return log_oom_debug();	×
441
442	if (EVP_DigestFinal_ex(mdctx, hash, &hash_size) != 1)	20✔
443	return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to finalize hash function.");	×
444
445	assert(hash_size == (unsigned) hsz);	20✔
446
447	*ret_hash = TAKE_PTR(hash);	20✔
448	*ret_hash_size = hash_size;	20✔
449
450	return 0;	20✔
451	}
452
453	int pe_checksum(int fd, uint32_t *ret) {	3✔
454	_cleanup_free_ IMAGE_DOS_HEADER *dos_header = NULL;	6✔
455	_cleanup_free_ PeHeader *pe_header = NULL;	3✔
456	struct stat st;	3✔
457	int r;	3✔
458
459	assert(fd >= 0);	3✔
460	assert(ret);	3✔
461
462	if (fstat(fd, &st) < 0)	3✔
463	return log_debug_errno(errno, "Failed to stat file: %m");	×
464
465	r = pe_load_headers(fd, &dos_header, &pe_header);	3✔
466	if (r < 0)	3✔
467	return r;
468
469	uint32_t checksum = 0, checksum_offset = le32toh(dos_header->e_lfanew) + offsetof(PeHeader, optional.CheckSum);	3✔
470	size_t off = 0;	3✔
471	for (;;) {	21✔
472	uint16_t buf[32*1024];	12✔
473
474	ssize_t n = pread(fd, buf, sizeof(buf), off);	12✔
475	if (n == 0)	12✔
476	break;
477	if (n < 0)	9✔
478	return log_debug_errno(errno, "Failed to read from PE file: %m");	×
479	if (n % sizeof(uint16_t) != 0)	9✔
480	return log_debug_errno(SYNTHETIC_ERRNO(EIO), "Short read from PE file");	×
481
482	for (size_t i = 0; i < (size_t) n / 2; i++) {	223,161✔
483	if (off + i >= checksum_offset && off + i < checksum_offset + sizeof(pe_header->optional.CheckSum))	223,152✔
484	continue;	12✔
485
486	uint16_t val = le16toh(buf[i]);	223,140✔
487
488	checksum += val;	223,140✔
489	checksum = (checksum >> 16) + (checksum & 0xffff);	223,140✔
490	}
491
492	off += n;	9✔
493	}
494
495	checksum = (checksum >> 16) + (checksum & 0xffff);	3✔
496	checksum += off;	3✔
497
498	*ret = checksum;	3✔
499	return 0;	3✔
500	}
501
502	typedef void* SectionHashArray[_UNIFIED_SECTION_MAX];
503
504	static void section_hash_array_done(SectionHashArray *array) {	8✔
505	assert(array);	8✔
506
507	for (size_t i = 0; i < _UNIFIED_SECTION_MAX; i++)	128✔
508	free((*array)[i]);	120✔
509	}	8✔
510
511	int uki_hash(int fd,	8✔
512	const EVP_MD *md,
513	void* ret_hashes[static _UNIFIED_SECTION_MAX],
514	size_t *ret_hash_size) {
515
516	_cleanup_(section_hash_array_done) SectionHashArray hashes = {};	×
517	_cleanup_free_ IMAGE_SECTION_HEADER *sections = NULL;	×
518	_cleanup_free_ IMAGE_DOS_HEADER *dos_header = NULL;	×
519	_cleanup_free_ PeHeader *pe_header = NULL;	8✔
520	int r;	8✔
521
522	assert(fd >= 0);	8✔
523	assert(ret_hashes);	8✔
524	assert(ret_hash_size);	8✔
525
526	r = pe_load_headers(fd, &dos_header, &pe_header);	8✔
527	if (r < 0)	8✔
528	return r;
529
530	r = pe_load_sections(fd, dos_header, pe_header, &sections);	8✔
531	if (r < 0)	8✔
532	return r;
533
534	int hsz = EVP_MD_size(md);	8✔
535	if (hsz < 0)	8✔
536	return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to get hash size.");	×
537
538	FOREACH_ARRAY(section, sections, pe_header->pe.NumberOfSections) {	64✔
539	_cleanup_(EVP_MD_CTX_freep) EVP_MD_CTX *mdctx = NULL;	16✔
540	_cleanup_free_ char *n = NULL;	56✔
541	ssize_t i;	56✔
542
543	n = memdup_suffix0(section->Name, sizeof(section->Name));	56✔
544	if (!n)	56✔
545	return log_oom_debug();	×
546
547	i = string_table_lookup_from_string(unified_sections, _UNIFIED_SECTION_MAX, n);	56✔
548	if (i < 0)	56✔
549	continue;	40✔
550
551	if (hashes[i])	16✔
552	return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "Duplicate section");	×
553
554	mdctx = EVP_MD_CTX_new();	16✔
555	if (!mdctx)	16✔
556	return log_oom_debug();	×
557
558	if (EVP_DigestInit_ex(mdctx, md, NULL) != 1)	16✔
559	return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to allocate message digest.");	×
560
561	r = hash_file(fd, mdctx, section->PointerToRawData, MIN(section->VirtualSize, section->SizeOfRawData));	16✔
562	if (r < 0)	16✔
563	return r;
564
565	if (section->SizeOfRawData < section->VirtualSize) {	16✔
566	uint8_t zeroes[1024] = {};	×
567	size_t remaining = section->VirtualSize - section->SizeOfRawData;	×
568
569	while (remaining > 0) {	×
570	size_t sz = MIN(sizeof(zeroes), remaining);	×
571
572	if (EVP_DigestUpdate(mdctx, zeroes, sz) != 1)	×
573	return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Unable to hash data.");	×
574
575	remaining -= sz;	×
576	}
577	}
578
579	hashes[i] = malloc(hsz);	16✔
580	if (!hashes[i])	16✔
581	return log_oom_debug();	×
582
583	unsigned hash_size = (unsigned) hsz;	16✔
584	if (EVP_DigestFinal_ex(mdctx, hashes[i], &hash_size) != 1)	16✔
585	return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to finalize hash function.");	×
586
587	assert(hash_size == (unsigned) hsz);	16✔
588
589	if (DEBUG_LOGGING) {	16✔
590	_cleanup_free_ char *hs = NULL;	16✔
591
592	hs = hexmem(hashes[i], hsz);	16✔
593	log_debug("Section %s with %s is %s.", n, EVP_MD_name(md), strna(hs));	16✔
594	}
595	}
596
597	memcpy(ret_hashes, hashes, sizeof(hashes));	8✔
598	zero(hashes);	8✔
599	*ret_hash_size = (unsigned) hsz;	8✔
600
601	return 0;	8✔
602	}
603	#endif

systemd / systemd / 19020191358

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