1e595e65bSEdward Tomasz Napierala /*- 2e595e65bSEdward Tomasz Napierala * Copyright (c) 2014 The FreeBSD Foundation 3e595e65bSEdward Tomasz Napierala * All rights reserved. 4e595e65bSEdward Tomasz Napierala * 5e595e65bSEdward Tomasz Napierala * This software was developed by Edward Tomasz Napierala under sponsorship 6e595e65bSEdward Tomasz Napierala * from the FreeBSD Foundation. 7e595e65bSEdward Tomasz Napierala * 8e595e65bSEdward Tomasz Napierala * Redistribution and use in source and binary forms, with or without 9e595e65bSEdward Tomasz Napierala * modification, are permitted provided that the following conditions 10e595e65bSEdward Tomasz Napierala * are met: 11e595e65bSEdward Tomasz Napierala * 1. Redistributions of source code must retain the above copyright 12e595e65bSEdward Tomasz Napierala * notice, this list of conditions and the following disclaimer. 13e595e65bSEdward Tomasz Napierala * 2. Redistributions in binary form must reproduce the above copyright 14e595e65bSEdward Tomasz Napierala * notice, this list of conditions and the following disclaimer in the 15e595e65bSEdward Tomasz Napierala * documentation and/or other materials provided with the distribution. 16e595e65bSEdward Tomasz Napierala * 17e595e65bSEdward Tomasz Napierala * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18e595e65bSEdward Tomasz Napierala * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19e595e65bSEdward Tomasz Napierala * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20e595e65bSEdward Tomasz Napierala * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21e595e65bSEdward Tomasz Napierala * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22e595e65bSEdward Tomasz Napierala * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23e595e65bSEdward Tomasz Napierala * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24e595e65bSEdward Tomasz Napierala * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25e595e65bSEdward Tomasz Napierala * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26e595e65bSEdward Tomasz Napierala * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27e595e65bSEdward Tomasz Napierala * SUCH DAMAGE. 28e595e65bSEdward Tomasz Napierala * 29e595e65bSEdward Tomasz Napierala */ 30e595e65bSEdward Tomasz Napierala 31e595e65bSEdward Tomasz Napierala /* 32e595e65bSEdward Tomasz Napierala * PE format reference: 33e595e65bSEdward Tomasz Napierala * http://www.microsoft.com/whdc/system/platform/firmware/PECOFF.mspx 34e595e65bSEdward Tomasz Napierala */ 35e595e65bSEdward Tomasz Napierala 36e595e65bSEdward Tomasz Napierala #include <sys/cdefs.h> 37e595e65bSEdward Tomasz Napierala __FBSDID("$FreeBSD$"); 38e595e65bSEdward Tomasz Napierala 39e595e65bSEdward Tomasz Napierala #include <assert.h> 40e595e65bSEdward Tomasz Napierala #include <err.h> 41e595e65bSEdward Tomasz Napierala #include <errno.h> 42e595e65bSEdward Tomasz Napierala #include <stddef.h> 43e595e65bSEdward Tomasz Napierala #include <stdio.h> 44e595e65bSEdward Tomasz Napierala #include <stdint.h> 45e595e65bSEdward Tomasz Napierala #include <stdlib.h> 46e595e65bSEdward Tomasz Napierala #include <string.h> 47e595e65bSEdward Tomasz Napierala #include <unistd.h> 48e595e65bSEdward Tomasz Napierala 49e595e65bSEdward Tomasz Napierala #include "uefisign.h" 50e595e65bSEdward Tomasz Napierala 51e595e65bSEdward Tomasz Napierala #ifndef CTASSERT 52e595e65bSEdward Tomasz Napierala #define CTASSERT(x) _CTASSERT(x, __LINE__) 53e595e65bSEdward Tomasz Napierala #define _CTASSERT(x, y) __CTASSERT(x, y) 54e595e65bSEdward Tomasz Napierala #define __CTASSERT(x, y) typedef char __assert_ ## y [(x) ? 1 : -1] 55e595e65bSEdward Tomasz Napierala #endif 56e595e65bSEdward Tomasz Napierala 57e595e65bSEdward Tomasz Napierala struct mz_header { 58e595e65bSEdward Tomasz Napierala uint8_t mz_signature[2]; 59e595e65bSEdward Tomasz Napierala uint8_t mz_dont_care[58]; 60e595e65bSEdward Tomasz Napierala uint16_t mz_lfanew; 61e595e65bSEdward Tomasz Napierala } __attribute__((packed)); 62e595e65bSEdward Tomasz Napierala 63e595e65bSEdward Tomasz Napierala struct coff_header { 64e595e65bSEdward Tomasz Napierala uint8_t coff_dont_care[2]; 65e595e65bSEdward Tomasz Napierala uint16_t coff_number_of_sections; 66e595e65bSEdward Tomasz Napierala uint8_t coff_dont_care_either[16]; 67e595e65bSEdward Tomasz Napierala } __attribute__((packed)); 68e595e65bSEdward Tomasz Napierala 69e595e65bSEdward Tomasz Napierala #define PE_SIGNATURE 0x00004550 70e595e65bSEdward Tomasz Napierala 71e595e65bSEdward Tomasz Napierala struct pe_header { 72e595e65bSEdward Tomasz Napierala uint32_t pe_signature; 73e595e65bSEdward Tomasz Napierala struct coff_header pe_coff; 74e595e65bSEdward Tomasz Napierala } __attribute__((packed)); 75e595e65bSEdward Tomasz Napierala 76e595e65bSEdward Tomasz Napierala #define PE_OPTIONAL_MAGIC_32 0x010B 77e595e65bSEdward Tomasz Napierala #define PE_OPTIONAL_MAGIC_32_PLUS 0x020B 78e595e65bSEdward Tomasz Napierala 79e595e65bSEdward Tomasz Napierala #define PE_OPTIONAL_SUBSYSTEM_EFI_APPLICATION 10 80e595e65bSEdward Tomasz Napierala #define PE_OPTIONAL_SUBSYSTEM_EFI_BOOT 11 81e595e65bSEdward Tomasz Napierala #define PE_OPTIONAL_SUBSYSTEM_EFI_RUNTIME 12 82e595e65bSEdward Tomasz Napierala 83e595e65bSEdward Tomasz Napierala struct pe_optional_header_32 { 84e595e65bSEdward Tomasz Napierala uint16_t po_magic; 85e595e65bSEdward Tomasz Napierala uint8_t po_dont_care[58]; 86e595e65bSEdward Tomasz Napierala uint32_t po_size_of_headers; 87e595e65bSEdward Tomasz Napierala uint32_t po_checksum; 88e595e65bSEdward Tomasz Napierala uint16_t po_subsystem; 89e595e65bSEdward Tomasz Napierala uint8_t po_dont_care_either[22]; 90e595e65bSEdward Tomasz Napierala uint32_t po_number_of_rva_and_sizes; 91e595e65bSEdward Tomasz Napierala } __attribute__((packed)); 92e595e65bSEdward Tomasz Napierala 93e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_optional_header_32, po_size_of_headers) == 60); 94e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_optional_header_32, po_checksum) == 64); 95e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_optional_header_32, po_subsystem) == 68); 96e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_optional_header_32, po_number_of_rva_and_sizes) == 92); 97e595e65bSEdward Tomasz Napierala 98e595e65bSEdward Tomasz Napierala struct pe_optional_header_32_plus { 99e595e65bSEdward Tomasz Napierala uint16_t po_magic; 100e595e65bSEdward Tomasz Napierala uint8_t po_dont_care[58]; 101e595e65bSEdward Tomasz Napierala uint32_t po_size_of_headers; 102e595e65bSEdward Tomasz Napierala uint32_t po_checksum; 103e595e65bSEdward Tomasz Napierala uint16_t po_subsystem; 104e595e65bSEdward Tomasz Napierala uint8_t po_dont_care_either[38]; 105e595e65bSEdward Tomasz Napierala uint32_t po_number_of_rva_and_sizes; 106e595e65bSEdward Tomasz Napierala } __attribute__((packed)); 107e595e65bSEdward Tomasz Napierala 108e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_optional_header_32_plus, po_size_of_headers) == 60); 109e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_optional_header_32_plus, po_checksum) == 64); 110e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_optional_header_32_plus, po_subsystem) == 68); 111e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_optional_header_32_plus, po_number_of_rva_and_sizes) == 108); 112e595e65bSEdward Tomasz Napierala 113e595e65bSEdward Tomasz Napierala #define PE_DIRECTORY_ENTRY_CERTIFICATE 4 114e595e65bSEdward Tomasz Napierala 115e595e65bSEdward Tomasz Napierala struct pe_directory_entry { 116e595e65bSEdward Tomasz Napierala uint32_t pde_rva; 117e595e65bSEdward Tomasz Napierala uint32_t pde_size; 118e595e65bSEdward Tomasz Napierala } __attribute__((packed)); 119e595e65bSEdward Tomasz Napierala 120e595e65bSEdward Tomasz Napierala struct pe_section_header { 121e595e65bSEdward Tomasz Napierala uint8_t psh_dont_care[16]; 122e595e65bSEdward Tomasz Napierala uint32_t psh_size_of_raw_data; 123e595e65bSEdward Tomasz Napierala uint32_t psh_pointer_to_raw_data; 124e595e65bSEdward Tomasz Napierala uint8_t psh_dont_care_either[16]; 125e595e65bSEdward Tomasz Napierala } __attribute__((packed)); 126e595e65bSEdward Tomasz Napierala 127e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_section_header, psh_size_of_raw_data) == 16); 128e595e65bSEdward Tomasz Napierala CTASSERT(offsetof(struct pe_section_header, psh_pointer_to_raw_data) == 20); 129e595e65bSEdward Tomasz Napierala 130e595e65bSEdward Tomasz Napierala #define PE_CERTIFICATE_REVISION 0x0200 131e595e65bSEdward Tomasz Napierala #define PE_CERTIFICATE_TYPE 0x0002 132e595e65bSEdward Tomasz Napierala 133e595e65bSEdward Tomasz Napierala struct pe_certificate { 134e595e65bSEdward Tomasz Napierala uint32_t pc_len; 135e595e65bSEdward Tomasz Napierala uint16_t pc_revision; 136e595e65bSEdward Tomasz Napierala uint16_t pc_type; 137e595e65bSEdward Tomasz Napierala char pc_signature[0]; 138e595e65bSEdward Tomasz Napierala } __attribute__((packed)); 139e595e65bSEdward Tomasz Napierala 140e595e65bSEdward Tomasz Napierala void 141e595e65bSEdward Tomasz Napierala range_check(const struct executable *x, off_t off, size_t len, 142e595e65bSEdward Tomasz Napierala const char *name) 143e595e65bSEdward Tomasz Napierala { 144e595e65bSEdward Tomasz Napierala 145e595e65bSEdward Tomasz Napierala if (off < 0) { 146e595e65bSEdward Tomasz Napierala errx(1, "%s starts at negative offset %jd", 147e595e65bSEdward Tomasz Napierala name, (intmax_t)off); 148e595e65bSEdward Tomasz Napierala } 149e595e65bSEdward Tomasz Napierala if (off >= (off_t)x->x_len) { 150e595e65bSEdward Tomasz Napierala errx(1, "%s starts at %jd, past the end of executable at %zd", 151e595e65bSEdward Tomasz Napierala name, (intmax_t)off, x->x_len); 152e595e65bSEdward Tomasz Napierala } 153e595e65bSEdward Tomasz Napierala if (len >= x->x_len) { 154e595e65bSEdward Tomasz Napierala errx(1, "%s size %zd is larger than the executable size %zd", 155e595e65bSEdward Tomasz Napierala name, len, x->x_len); 156e595e65bSEdward Tomasz Napierala } 157e595e65bSEdward Tomasz Napierala if (off + len > x->x_len) { 158e595e65bSEdward Tomasz Napierala errx(1, "%s extends to %jd, past the end of executable at %zd", 159e595e65bSEdward Tomasz Napierala name, (intmax_t)(off + len), x->x_len); 160e595e65bSEdward Tomasz Napierala } 161e595e65bSEdward Tomasz Napierala } 162e595e65bSEdward Tomasz Napierala 163e595e65bSEdward Tomasz Napierala size_t 164e595e65bSEdward Tomasz Napierala signature_size(const struct executable *x) 165e595e65bSEdward Tomasz Napierala { 166e595e65bSEdward Tomasz Napierala const struct pe_directory_entry *pde; 167e595e65bSEdward Tomasz Napierala 168e595e65bSEdward Tomasz Napierala range_check(x, x->x_certificate_entry_off, 169e595e65bSEdward Tomasz Napierala x->x_certificate_entry_len, "Certificate Directory"); 170e595e65bSEdward Tomasz Napierala 171e595e65bSEdward Tomasz Napierala pde = (struct pe_directory_entry *) 172e595e65bSEdward Tomasz Napierala (x->x_buf + x->x_certificate_entry_off); 173e595e65bSEdward Tomasz Napierala 174e595e65bSEdward Tomasz Napierala if (pde->pde_rva != 0 && pde->pde_size == 0) 175e595e65bSEdward Tomasz Napierala warnx("signature size is 0, but its RVA is %d", pde->pde_rva); 176e595e65bSEdward Tomasz Napierala if (pde->pde_rva == 0 && pde->pde_size != 0) 177e595e65bSEdward Tomasz Napierala warnx("signature RVA is 0, but its size is %d", pde->pde_size); 178e595e65bSEdward Tomasz Napierala 179e595e65bSEdward Tomasz Napierala return (pde->pde_size); 180e595e65bSEdward Tomasz Napierala } 181e595e65bSEdward Tomasz Napierala 182e595e65bSEdward Tomasz Napierala void 183e595e65bSEdward Tomasz Napierala show_certificate(const struct executable *x) 184e595e65bSEdward Tomasz Napierala { 185e595e65bSEdward Tomasz Napierala struct pe_certificate *pc; 186e595e65bSEdward Tomasz Napierala const struct pe_directory_entry *pde; 187e595e65bSEdward Tomasz Napierala 188e595e65bSEdward Tomasz Napierala range_check(x, x->x_certificate_entry_off, 189e595e65bSEdward Tomasz Napierala x->x_certificate_entry_len, "Certificate Directory"); 190e595e65bSEdward Tomasz Napierala 191e595e65bSEdward Tomasz Napierala pde = (struct pe_directory_entry *) 192e595e65bSEdward Tomasz Napierala (x->x_buf + x->x_certificate_entry_off); 193e595e65bSEdward Tomasz Napierala 194e595e65bSEdward Tomasz Napierala if (signature_size(x) == 0) { 195e595e65bSEdward Tomasz Napierala printf("file not signed\n"); 196e595e65bSEdward Tomasz Napierala return; 197e595e65bSEdward Tomasz Napierala } 198e595e65bSEdward Tomasz Napierala 199e595e65bSEdward Tomasz Napierala #if 0 200e595e65bSEdward Tomasz Napierala printf("certificate chunk at offset %zd, size %zd\n", 201e595e65bSEdward Tomasz Napierala pde->pde_rva, pde->pde_size); 202e595e65bSEdward Tomasz Napierala #endif 203e595e65bSEdward Tomasz Napierala 204e595e65bSEdward Tomasz Napierala range_check(x, pde->pde_rva, pde->pde_size, "Certificate chunk"); 205e595e65bSEdward Tomasz Napierala 206e595e65bSEdward Tomasz Napierala pc = (struct pe_certificate *)(x->x_buf + pde->pde_rva); 207e595e65bSEdward Tomasz Napierala if (pc->pc_revision != PE_CERTIFICATE_REVISION) { 208e595e65bSEdward Tomasz Napierala errx(1, "wrong certificate chunk revision, is %d, should be %d", 209e595e65bSEdward Tomasz Napierala pc->pc_revision, PE_CERTIFICATE_REVISION); 210e595e65bSEdward Tomasz Napierala } 211e595e65bSEdward Tomasz Napierala if (pc->pc_type != PE_CERTIFICATE_TYPE) { 212e595e65bSEdward Tomasz Napierala errx(1, "wrong certificate chunk type, is %d, should be %d", 213e595e65bSEdward Tomasz Napierala pc->pc_type, PE_CERTIFICATE_TYPE); 214e595e65bSEdward Tomasz Napierala } 215e595e65bSEdward Tomasz Napierala printf("to dump PKCS7:\n " 216e595e65bSEdward Tomasz Napierala "dd if='%s' bs=1 skip=%zd | openssl pkcs7 -inform DER -print\n", 217e595e65bSEdward Tomasz Napierala x->x_path, pde->pde_rva + offsetof(struct pe_certificate, pc_signature)); 218e595e65bSEdward Tomasz Napierala printf("to dump raw ASN.1:\n " 219e595e65bSEdward Tomasz Napierala "openssl asn1parse -i -inform DER -offset %zd -in '%s'\n", 220e595e65bSEdward Tomasz Napierala pde->pde_rva + offsetof(struct pe_certificate, pc_signature), x->x_path); 221e595e65bSEdward Tomasz Napierala } 222e595e65bSEdward Tomasz Napierala 223e595e65bSEdward Tomasz Napierala static void 224e595e65bSEdward Tomasz Napierala parse_section_table(struct executable *x, off_t off, int number_of_sections) 225e595e65bSEdward Tomasz Napierala { 226e595e65bSEdward Tomasz Napierala const struct pe_section_header *psh; 227e595e65bSEdward Tomasz Napierala int i; 228e595e65bSEdward Tomasz Napierala 229e595e65bSEdward Tomasz Napierala range_check(x, off, sizeof(*psh) * number_of_sections, 230e595e65bSEdward Tomasz Napierala "section table"); 231e595e65bSEdward Tomasz Napierala 232e595e65bSEdward Tomasz Napierala if (x->x_headers_len <= off + sizeof(*psh) * number_of_sections) 233e595e65bSEdward Tomasz Napierala errx(1, "section table outside of headers"); 234e595e65bSEdward Tomasz Napierala 235e595e65bSEdward Tomasz Napierala psh = (const struct pe_section_header *)(x->x_buf + off); 236e595e65bSEdward Tomasz Napierala 237e595e65bSEdward Tomasz Napierala if (number_of_sections >= MAX_SECTIONS) { 238e595e65bSEdward Tomasz Napierala errx(1, "too many sections: got %d, should be %d", 239e595e65bSEdward Tomasz Napierala number_of_sections, MAX_SECTIONS); 240e595e65bSEdward Tomasz Napierala } 241e595e65bSEdward Tomasz Napierala x->x_nsections = number_of_sections; 242e595e65bSEdward Tomasz Napierala 243e595e65bSEdward Tomasz Napierala for (i = 0; i < number_of_sections; i++) { 244e595e65bSEdward Tomasz Napierala if (psh->psh_pointer_to_raw_data < x->x_headers_len) 245e595e65bSEdward Tomasz Napierala errx(1, "section points inside the headers"); 246e595e65bSEdward Tomasz Napierala 247e595e65bSEdward Tomasz Napierala range_check(x, psh->psh_pointer_to_raw_data, 248e595e65bSEdward Tomasz Napierala psh->psh_size_of_raw_data, "section"); 249e595e65bSEdward Tomasz Napierala #if 0 250e595e65bSEdward Tomasz Napierala printf("section %d: start %d, size %d\n", 251e595e65bSEdward Tomasz Napierala i, psh->psh_pointer_to_raw_data, psh->psh_size_of_raw_data); 252e595e65bSEdward Tomasz Napierala #endif 253e595e65bSEdward Tomasz Napierala x->x_section_off[i] = psh->psh_pointer_to_raw_data; 254e595e65bSEdward Tomasz Napierala x->x_section_len[i] = psh->psh_size_of_raw_data; 255e595e65bSEdward Tomasz Napierala psh++; 256e595e65bSEdward Tomasz Napierala } 257e595e65bSEdward Tomasz Napierala } 258e595e65bSEdward Tomasz Napierala 259e595e65bSEdward Tomasz Napierala static void 260e595e65bSEdward Tomasz Napierala parse_directory(struct executable *x, off_t off, 261e595e65bSEdward Tomasz Napierala int number_of_rva_and_sizes, int number_of_sections) 262e595e65bSEdward Tomasz Napierala { 263e595e65bSEdward Tomasz Napierala //int i; 264e595e65bSEdward Tomasz Napierala const struct pe_directory_entry *pde; 265e595e65bSEdward Tomasz Napierala 266e595e65bSEdward Tomasz Napierala //printf("Data Directory at offset %zd\n", off); 267e595e65bSEdward Tomasz Napierala 268e595e65bSEdward Tomasz Napierala if (number_of_rva_and_sizes <= PE_DIRECTORY_ENTRY_CERTIFICATE) { 269e595e65bSEdward Tomasz Napierala errx(1, "wrong NumberOfRvaAndSizes %d; should be at least %d", 270e595e65bSEdward Tomasz Napierala number_of_rva_and_sizes, PE_DIRECTORY_ENTRY_CERTIFICATE); 271e595e65bSEdward Tomasz Napierala } 272e595e65bSEdward Tomasz Napierala 273e595e65bSEdward Tomasz Napierala range_check(x, off, sizeof(*pde) * number_of_rva_and_sizes, 274e595e65bSEdward Tomasz Napierala "PE Data Directory"); 275e595e65bSEdward Tomasz Napierala if (x->x_headers_len <= off + sizeof(*pde) * number_of_rva_and_sizes) 276e595e65bSEdward Tomasz Napierala errx(1, "PE Data Directory outside of headers"); 277e595e65bSEdward Tomasz Napierala 278e595e65bSEdward Tomasz Napierala x->x_certificate_entry_off = 279e595e65bSEdward Tomasz Napierala off + sizeof(*pde) * PE_DIRECTORY_ENTRY_CERTIFICATE; 280e595e65bSEdward Tomasz Napierala x->x_certificate_entry_len = sizeof(*pde); 281e595e65bSEdward Tomasz Napierala #if 0 282e595e65bSEdward Tomasz Napierala printf("certificate directory entry at offset %zd, len %zd\n", 283e595e65bSEdward Tomasz Napierala x->x_certificate_entry_off, x->x_certificate_entry_len); 284e595e65bSEdward Tomasz Napierala 285e595e65bSEdward Tomasz Napierala pde = (struct pe_directory_entry *)(x->x_buf + off); 286e595e65bSEdward Tomasz Napierala for (i = 0; i < number_of_rva_and_sizes; i++) { 287e595e65bSEdward Tomasz Napierala printf("rva %zd, size %zd\n", pde->pde_rva, pde->pde_size); 288e595e65bSEdward Tomasz Napierala pde++; 289e595e65bSEdward Tomasz Napierala } 290e595e65bSEdward Tomasz Napierala #endif 291e595e65bSEdward Tomasz Napierala 292e595e65bSEdward Tomasz Napierala return (parse_section_table(x, 293e595e65bSEdward Tomasz Napierala off + sizeof(*pde) * number_of_rva_and_sizes, number_of_sections)); 294e595e65bSEdward Tomasz Napierala } 295e595e65bSEdward Tomasz Napierala 296e595e65bSEdward Tomasz Napierala /* 297e595e65bSEdward Tomasz Napierala * The PE checksum algorithm is undocumented; this code is mostly based on 298e595e65bSEdward Tomasz Napierala * http://forum.sysinternals.com/optional-header-checksum-calculation_topic24214.html 299e595e65bSEdward Tomasz Napierala * 300e595e65bSEdward Tomasz Napierala * "Sum the entire image file, excluding the CheckSum field in the optional 301e595e65bSEdward Tomasz Napierala * header, as an array of USHORTs, allowing any carry above 16 bits to be added 302e595e65bSEdward Tomasz Napierala * back onto the low 16 bits. Then add the file size to get a 32-bit value." 303e595e65bSEdward Tomasz Napierala * 304e595e65bSEdward Tomasz Napierala * Note that most software does not care about the checksum at all; perhaps 305e595e65bSEdward Tomasz Napierala * we could just set it to 0 instead. 306e595e65bSEdward Tomasz Napierala * 307e595e65bSEdward Tomasz Napierala * XXX: Endianess? 308e595e65bSEdward Tomasz Napierala */ 309e595e65bSEdward Tomasz Napierala static uint32_t 310e595e65bSEdward Tomasz Napierala compute_checksum(const struct executable *x) 311e595e65bSEdward Tomasz Napierala { 312e595e65bSEdward Tomasz Napierala uint32_t cksum = 0; 313e595e65bSEdward Tomasz Napierala uint16_t tmp; 314e595e65bSEdward Tomasz Napierala int i; 315e595e65bSEdward Tomasz Napierala 316e595e65bSEdward Tomasz Napierala range_check(x, x->x_checksum_off, x->x_checksum_len, "PE checksum"); 317e595e65bSEdward Tomasz Napierala 318e595e65bSEdward Tomasz Napierala assert(x->x_checksum_off % 2 == 0); 319e595e65bSEdward Tomasz Napierala 320e595e65bSEdward Tomasz Napierala for (i = 0; i + sizeof(tmp) < x->x_len; i += 2) { 321e595e65bSEdward Tomasz Napierala /* 322e595e65bSEdward Tomasz Napierala * Don't checksum the checksum. The +2 is because the checksum 323e595e65bSEdward Tomasz Napierala * is 4 bytes, and here we're iterating over 2 byte chunks. 324e595e65bSEdward Tomasz Napierala */ 325e595e65bSEdward Tomasz Napierala if (i == x->x_checksum_off || i == x->x_checksum_off + 2) { 326e595e65bSEdward Tomasz Napierala tmp = 0; 327e595e65bSEdward Tomasz Napierala } else { 328e595e65bSEdward Tomasz Napierala assert(i + sizeof(tmp) <= x->x_len); 329e595e65bSEdward Tomasz Napierala memcpy(&tmp, x->x_buf + i, sizeof(tmp)); 330e595e65bSEdward Tomasz Napierala } 331e595e65bSEdward Tomasz Napierala 332e595e65bSEdward Tomasz Napierala cksum += tmp; 333e595e65bSEdward Tomasz Napierala cksum += cksum >> 16; 334e595e65bSEdward Tomasz Napierala cksum &= 0xffff; 335e595e65bSEdward Tomasz Napierala } 336e595e65bSEdward Tomasz Napierala 337e595e65bSEdward Tomasz Napierala cksum += cksum >> 16; 338e595e65bSEdward Tomasz Napierala cksum &= 0xffff; 339e595e65bSEdward Tomasz Napierala 340e595e65bSEdward Tomasz Napierala cksum += x->x_len; 341e595e65bSEdward Tomasz Napierala 342e595e65bSEdward Tomasz Napierala return (cksum); 343e595e65bSEdward Tomasz Napierala } 344e595e65bSEdward Tomasz Napierala 345e595e65bSEdward Tomasz Napierala static void 346e595e65bSEdward Tomasz Napierala parse_optional_32_plus(struct executable *x, off_t off, 347e595e65bSEdward Tomasz Napierala int number_of_sections) 348e595e65bSEdward Tomasz Napierala { 349*8dca98d7SEdward Tomasz Napierala #if 0 350e595e65bSEdward Tomasz Napierala uint32_t computed_checksum; 351*8dca98d7SEdward Tomasz Napierala #endif 352e595e65bSEdward Tomasz Napierala const struct pe_optional_header_32_plus *po; 353e595e65bSEdward Tomasz Napierala 354e595e65bSEdward Tomasz Napierala range_check(x, off, sizeof(*po), "PE Optional Header"); 355e595e65bSEdward Tomasz Napierala 356e595e65bSEdward Tomasz Napierala po = (struct pe_optional_header_32_plus *)(x->x_buf + off); 357e595e65bSEdward Tomasz Napierala switch (po->po_subsystem) { 358e595e65bSEdward Tomasz Napierala case PE_OPTIONAL_SUBSYSTEM_EFI_APPLICATION: 359e595e65bSEdward Tomasz Napierala case PE_OPTIONAL_SUBSYSTEM_EFI_BOOT: 360e595e65bSEdward Tomasz Napierala case PE_OPTIONAL_SUBSYSTEM_EFI_RUNTIME: 361e595e65bSEdward Tomasz Napierala break; 362e595e65bSEdward Tomasz Napierala default: 363e595e65bSEdward Tomasz Napierala errx(1, "wrong PE Optional Header subsystem 0x%x", 364e595e65bSEdward Tomasz Napierala po->po_subsystem); 365e595e65bSEdward Tomasz Napierala } 366e595e65bSEdward Tomasz Napierala 367e595e65bSEdward Tomasz Napierala #if 0 368e595e65bSEdward Tomasz Napierala printf("subsystem %d, checksum 0x%x, %d data directories\n", 369e595e65bSEdward Tomasz Napierala po->po_subsystem, po->po_checksum, po->po_number_of_rva_and_sizes); 370e595e65bSEdward Tomasz Napierala #endif 371e595e65bSEdward Tomasz Napierala 372e595e65bSEdward Tomasz Napierala x->x_checksum_off = off + 373e595e65bSEdward Tomasz Napierala offsetof(struct pe_optional_header_32_plus, po_checksum); 374e595e65bSEdward Tomasz Napierala x->x_checksum_len = sizeof(po->po_checksum); 375e595e65bSEdward Tomasz Napierala #if 0 376e595e65bSEdward Tomasz Napierala printf("checksum 0x%x at offset %zd, len %zd\n", 377e595e65bSEdward Tomasz Napierala po->po_checksum, x->x_checksum_off, x->x_checksum_len); 378e595e65bSEdward Tomasz Napierala 379e595e65bSEdward Tomasz Napierala computed_checksum = compute_checksum(x); 380e595e65bSEdward Tomasz Napierala if (computed_checksum != po->po_checksum) { 381e595e65bSEdward Tomasz Napierala warnx("invalid PE+ checksum; is 0x%x, should be 0x%x", 382e595e65bSEdward Tomasz Napierala po->po_checksum, computed_checksum); 383e595e65bSEdward Tomasz Napierala } 384*8dca98d7SEdward Tomasz Napierala #endif 385e595e65bSEdward Tomasz Napierala 386e595e65bSEdward Tomasz Napierala if (x->x_len < x->x_headers_len) 387e595e65bSEdward Tomasz Napierala errx(1, "invalid SizeOfHeaders %d", po->po_size_of_headers); 388e595e65bSEdward Tomasz Napierala x->x_headers_len = po->po_size_of_headers; 389e595e65bSEdward Tomasz Napierala //printf("Size of Headers: %d\n", po->po_size_of_headers); 390e595e65bSEdward Tomasz Napierala 391e595e65bSEdward Tomasz Napierala return (parse_directory(x, off + sizeof(*po), 392e595e65bSEdward Tomasz Napierala po->po_number_of_rva_and_sizes, number_of_sections)); 393e595e65bSEdward Tomasz Napierala } 394e595e65bSEdward Tomasz Napierala 395e595e65bSEdward Tomasz Napierala static void 396e595e65bSEdward Tomasz Napierala parse_optional_32(struct executable *x, off_t off, int number_of_sections) 397e595e65bSEdward Tomasz Napierala { 398*8dca98d7SEdward Tomasz Napierala #if 0 399e595e65bSEdward Tomasz Napierala uint32_t computed_checksum; 400*8dca98d7SEdward Tomasz Napierala #endif 401e595e65bSEdward Tomasz Napierala const struct pe_optional_header_32 *po; 402e595e65bSEdward Tomasz Napierala 403e595e65bSEdward Tomasz Napierala range_check(x, off, sizeof(*po), "PE Optional Header"); 404e595e65bSEdward Tomasz Napierala 405e595e65bSEdward Tomasz Napierala po = (struct pe_optional_header_32 *)(x->x_buf + off); 406e595e65bSEdward Tomasz Napierala switch (po->po_subsystem) { 407e595e65bSEdward Tomasz Napierala case PE_OPTIONAL_SUBSYSTEM_EFI_APPLICATION: 408e595e65bSEdward Tomasz Napierala case PE_OPTIONAL_SUBSYSTEM_EFI_BOOT: 409e595e65bSEdward Tomasz Napierala case PE_OPTIONAL_SUBSYSTEM_EFI_RUNTIME: 410e595e65bSEdward Tomasz Napierala break; 411e595e65bSEdward Tomasz Napierala default: 412e595e65bSEdward Tomasz Napierala errx(1, "wrong PE Optional Header subsystem 0x%x", 413e595e65bSEdward Tomasz Napierala po->po_subsystem); 414e595e65bSEdward Tomasz Napierala } 415e595e65bSEdward Tomasz Napierala 416e595e65bSEdward Tomasz Napierala #if 0 417e595e65bSEdward Tomasz Napierala printf("subsystem %d, checksum 0x%x, %d data directories\n", 418e595e65bSEdward Tomasz Napierala po->po_subsystem, po->po_checksum, po->po_number_of_rva_and_sizes); 419e595e65bSEdward Tomasz Napierala #endif 420e595e65bSEdward Tomasz Napierala 421e595e65bSEdward Tomasz Napierala x->x_checksum_off = off + 422e595e65bSEdward Tomasz Napierala offsetof(struct pe_optional_header_32, po_checksum); 423e595e65bSEdward Tomasz Napierala x->x_checksum_len = sizeof(po->po_checksum); 424e595e65bSEdward Tomasz Napierala #if 0 425e595e65bSEdward Tomasz Napierala printf("checksum at offset %zd, len %zd\n", 426e595e65bSEdward Tomasz Napierala x->x_checksum_off, x->x_checksum_len); 427e595e65bSEdward Tomasz Napierala 428e595e65bSEdward Tomasz Napierala computed_checksum = compute_checksum(x); 429e595e65bSEdward Tomasz Napierala if (computed_checksum != po->po_checksum) { 430e595e65bSEdward Tomasz Napierala warnx("invalid PE checksum; is 0x%x, should be 0x%x", 431e595e65bSEdward Tomasz Napierala po->po_checksum, computed_checksum); 432e595e65bSEdward Tomasz Napierala } 433*8dca98d7SEdward Tomasz Napierala #endif 434e595e65bSEdward Tomasz Napierala 435e595e65bSEdward Tomasz Napierala if (x->x_len < x->x_headers_len) 436e595e65bSEdward Tomasz Napierala errx(1, "invalid SizeOfHeaders %d", po->po_size_of_headers); 437e595e65bSEdward Tomasz Napierala x->x_headers_len = po->po_size_of_headers; 438e595e65bSEdward Tomasz Napierala //printf("Size of Headers: %d\n", po->po_size_of_headers); 439e595e65bSEdward Tomasz Napierala 440e595e65bSEdward Tomasz Napierala return (parse_directory(x, off + sizeof(*po), 441e595e65bSEdward Tomasz Napierala po->po_number_of_rva_and_sizes, number_of_sections)); 442e595e65bSEdward Tomasz Napierala } 443e595e65bSEdward Tomasz Napierala 444e595e65bSEdward Tomasz Napierala static void 445e595e65bSEdward Tomasz Napierala parse_optional(struct executable *x, off_t off, int number_of_sections) 446e595e65bSEdward Tomasz Napierala { 447e595e65bSEdward Tomasz Napierala const struct pe_optional_header_32 *po; 448e595e65bSEdward Tomasz Napierala 449e595e65bSEdward Tomasz Napierala //printf("Optional header offset %zd\n", off); 450e595e65bSEdward Tomasz Napierala 451e595e65bSEdward Tomasz Napierala range_check(x, off, sizeof(*po), "PE Optional Header"); 452e595e65bSEdward Tomasz Napierala 453e595e65bSEdward Tomasz Napierala po = (struct pe_optional_header_32 *)(x->x_buf + off); 454e595e65bSEdward Tomasz Napierala 455e595e65bSEdward Tomasz Napierala switch (po->po_magic) { 456e595e65bSEdward Tomasz Napierala case PE_OPTIONAL_MAGIC_32: 457e595e65bSEdward Tomasz Napierala return (parse_optional_32(x, off, number_of_sections)); 458e595e65bSEdward Tomasz Napierala case PE_OPTIONAL_MAGIC_32_PLUS: 459e595e65bSEdward Tomasz Napierala return (parse_optional_32_plus(x, off, number_of_sections)); 460e595e65bSEdward Tomasz Napierala default: 461e595e65bSEdward Tomasz Napierala errx(1, "wrong PE Optional Header magic 0x%x", po->po_magic); 462e595e65bSEdward Tomasz Napierala } 463e595e65bSEdward Tomasz Napierala } 464e595e65bSEdward Tomasz Napierala 465e595e65bSEdward Tomasz Napierala static void 466e595e65bSEdward Tomasz Napierala parse_pe(struct executable *x, off_t off) 467e595e65bSEdward Tomasz Napierala { 468e595e65bSEdward Tomasz Napierala const struct pe_header *pe; 469e595e65bSEdward Tomasz Napierala 470e595e65bSEdward Tomasz Napierala //printf("PE offset %zd, PE size %zd\n", off, sizeof(*pe)); 471e595e65bSEdward Tomasz Napierala 472e595e65bSEdward Tomasz Napierala range_check(x, off, sizeof(*pe), "PE header"); 473e595e65bSEdward Tomasz Napierala 474e595e65bSEdward Tomasz Napierala pe = (struct pe_header *)(x->x_buf + off); 475e595e65bSEdward Tomasz Napierala if (pe->pe_signature != PE_SIGNATURE) 476e595e65bSEdward Tomasz Napierala errx(1, "wrong PE signature 0x%x", pe->pe_signature); 477e595e65bSEdward Tomasz Napierala 478e595e65bSEdward Tomasz Napierala //printf("Number of sections: %d\n", pe->pe_coff.coff_number_of_sections); 479e595e65bSEdward Tomasz Napierala 480e595e65bSEdward Tomasz Napierala parse_optional(x, off + sizeof(*pe), 481e595e65bSEdward Tomasz Napierala pe->pe_coff.coff_number_of_sections); 482e595e65bSEdward Tomasz Napierala } 483e595e65bSEdward Tomasz Napierala 484e595e65bSEdward Tomasz Napierala void 485e595e65bSEdward Tomasz Napierala parse(struct executable *x) 486e595e65bSEdward Tomasz Napierala { 487e595e65bSEdward Tomasz Napierala const struct mz_header *mz; 488e595e65bSEdward Tomasz Napierala 489e595e65bSEdward Tomasz Napierala range_check(x, 0, sizeof(*mz), "MZ header"); 490e595e65bSEdward Tomasz Napierala 491e595e65bSEdward Tomasz Napierala mz = (struct mz_header *)x->x_buf; 492e595e65bSEdward Tomasz Napierala if (mz->mz_signature[0] != 'M' || mz->mz_signature[1] != 'Z') 493e595e65bSEdward Tomasz Napierala errx(1, "MZ header not found"); 494e595e65bSEdward Tomasz Napierala 495e595e65bSEdward Tomasz Napierala return (parse_pe(x, mz->mz_lfanew)); 496e595e65bSEdward Tomasz Napierala } 497e595e65bSEdward Tomasz Napierala 498e595e65bSEdward Tomasz Napierala static off_t 499e595e65bSEdward Tomasz Napierala append(struct executable *x, void *ptr, size_t len) 500e595e65bSEdward Tomasz Napierala { 501e595e65bSEdward Tomasz Napierala off_t off; 502e595e65bSEdward Tomasz Napierala 503e595e65bSEdward Tomasz Napierala /* 504e595e65bSEdward Tomasz Napierala * XXX: Alignment. 505e595e65bSEdward Tomasz Napierala */ 506e595e65bSEdward Tomasz Napierala off = x->x_len; 507e595e65bSEdward Tomasz Napierala x->x_buf = realloc(x->x_buf, x->x_len + len); 508e595e65bSEdward Tomasz Napierala if (x->x_buf == NULL) 509e595e65bSEdward Tomasz Napierala err(1, "realloc"); 510e595e65bSEdward Tomasz Napierala memcpy(x->x_buf + x->x_len, ptr, len); 511e595e65bSEdward Tomasz Napierala x->x_len += len; 512e595e65bSEdward Tomasz Napierala 513e595e65bSEdward Tomasz Napierala return (off); 514e595e65bSEdward Tomasz Napierala } 515e595e65bSEdward Tomasz Napierala 516e595e65bSEdward Tomasz Napierala void 517e595e65bSEdward Tomasz Napierala update(struct executable *x) 518e595e65bSEdward Tomasz Napierala { 519e595e65bSEdward Tomasz Napierala uint32_t checksum; 520e595e65bSEdward Tomasz Napierala struct pe_certificate *pc; 521e595e65bSEdward Tomasz Napierala struct pe_directory_entry pde; 522e595e65bSEdward Tomasz Napierala size_t pc_len; 523e595e65bSEdward Tomasz Napierala off_t pc_off; 524e595e65bSEdward Tomasz Napierala 525e595e65bSEdward Tomasz Napierala pc_len = sizeof(*pc) + x->x_signature_len; 526e595e65bSEdward Tomasz Napierala pc = calloc(1, pc_len); 527e595e65bSEdward Tomasz Napierala if (pc == NULL) 528e595e65bSEdward Tomasz Napierala err(1, "calloc"); 529e595e65bSEdward Tomasz Napierala 530e595e65bSEdward Tomasz Napierala #if 0 531e595e65bSEdward Tomasz Napierala /* 532e595e65bSEdward Tomasz Napierala * Note that pc_len is the length of pc_certificate, 533e595e65bSEdward Tomasz Napierala * not the whole structure. 534e595e65bSEdward Tomasz Napierala * 535e595e65bSEdward Tomasz Napierala * XXX: That's what the spec says - but it breaks at least 536e595e65bSEdward Tomasz Napierala * sbverify and "pesign -S", so the spec is probably wrong. 537e595e65bSEdward Tomasz Napierala */ 538e595e65bSEdward Tomasz Napierala pc->pc_len = x->x_signature_len; 539e595e65bSEdward Tomasz Napierala #else 540e595e65bSEdward Tomasz Napierala pc->pc_len = pc_len; 541e595e65bSEdward Tomasz Napierala #endif 542e595e65bSEdward Tomasz Napierala pc->pc_revision = PE_CERTIFICATE_REVISION; 543e595e65bSEdward Tomasz Napierala pc->pc_type = PE_CERTIFICATE_TYPE; 544e595e65bSEdward Tomasz Napierala memcpy(&pc->pc_signature, x->x_signature, x->x_signature_len); 545e595e65bSEdward Tomasz Napierala 546e595e65bSEdward Tomasz Napierala pc_off = append(x, pc, pc_len); 547e595e65bSEdward Tomasz Napierala #if 0 548e595e65bSEdward Tomasz Napierala printf("added signature chunk at offset %zd, len %zd\n", 549e595e65bSEdward Tomasz Napierala pc_off, pc_len); 550e595e65bSEdward Tomasz Napierala #endif 551e595e65bSEdward Tomasz Napierala 552e595e65bSEdward Tomasz Napierala free(pc); 553e595e65bSEdward Tomasz Napierala 554e595e65bSEdward Tomasz Napierala pde.pde_rva = pc_off; 555e595e65bSEdward Tomasz Napierala pde.pde_size = pc_len; 556e595e65bSEdward Tomasz Napierala memcpy(x->x_buf + x->x_certificate_entry_off, &pde, sizeof(pde)); 557e595e65bSEdward Tomasz Napierala 558e595e65bSEdward Tomasz Napierala checksum = compute_checksum(x); 559e595e65bSEdward Tomasz Napierala assert(sizeof(checksum) == x->x_checksum_len); 560e595e65bSEdward Tomasz Napierala memcpy(x->x_buf + x->x_checksum_off, &checksum, sizeof(checksum)); 561e595e65bSEdward Tomasz Napierala #if 0 562e595e65bSEdward Tomasz Napierala printf("new checksum 0x%x\n", checksum); 563e595e65bSEdward Tomasz Napierala #endif 564e595e65bSEdward Tomasz Napierala } 565