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authorLinus Torvalds <torvalds@linux-foundation.org>2016-03-17 11:33:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-17 11:33:45 -0700
commitbb7aeae3d680c2c777f54274b0270ced0599f33d (patch)
tree4801a103c2b157b5019cf38a19dc67d54bf38453 /scripts/insert-sys-cert.c
parent70477371dc350746d10431d74f0f213a8d59924c (diff)
parent88a1b564a20e371e6be41b39b85673e9c1959491 (diff)
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Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security layer updates from James Morris: "There are a bunch of fixes to the TPM, IMA, and Keys code, with minor fixes scattered across the subsystem. IMA now requires signed policy, and that policy is also now measured and appraised" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (67 commits) X.509: Make algo identifiers text instead of enum akcipher: Move the RSA DER encoding check to the crypto layer crypto: Add hash param to pkcs1pad sign-file: fix build with CMS support disabled MAINTAINERS: update tpmdd urls MODSIGN: linux/string.h should be #included to get memcpy() certs: Fix misaligned data in extra certificate list X.509: Handle midnight alternative notation in GeneralizedTime X.509: Support leap seconds Handle ISO 8601 leap seconds and encodings of midnight in mktime64() X.509: Fix leap year handling again PKCS#7: fix unitialized boolean 'want' firmware: change kernel read fail to dev_dbg() KEYS: Use the symbol value for list size, updated by scripts/insert-sys-cert KEYS: Reserve an extra certificate symbol for inserting without recompiling modsign: hide openssl output in silent builds tpm_tis: fix build warning with tpm_tis_resume ima: require signed IMA policy ima: measure and appraise the IMA policy itself ima: load policy using path ...
Diffstat (limited to 'scripts/insert-sys-cert.c')
-rw-r--r--scripts/insert-sys-cert.c410
1 files changed, 410 insertions, 0 deletions
diff --git a/scripts/insert-sys-cert.c b/scripts/insert-sys-cert.c
new file mode 100644
index 000000000000..8902836c2342
--- /dev/null
+++ b/scripts/insert-sys-cert.c
@@ -0,0 +1,410 @@
+/* Write the contents of the <certfile> into kernel symbol system_extra_cert
+ *
+ * Copyright (C) IBM Corporation, 2015
+ *
+ * Author: Mehmet Kayaalp <mkayaalp@linux.vnet.ibm.com>
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ * Usage: insert-sys-cert [-s <System.map> -b <vmlinux> -c <certfile>
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <elf.h>
+
+#define CERT_SYM "system_extra_cert"
+#define USED_SYM "system_extra_cert_used"
+#define LSIZE_SYM "system_certificate_list_size"
+
+#define info(format, args...) fprintf(stderr, "INFO: " format, ## args)
+#define warn(format, args...) fprintf(stdout, "WARNING: " format, ## args)
+#define err(format, args...) fprintf(stderr, "ERROR: " format, ## args)
+
+#if UINTPTR_MAX == 0xffffffff
+#define CURRENT_ELFCLASS ELFCLASS32
+#define Elf_Ehdr Elf32_Ehdr
+#define Elf_Shdr Elf32_Shdr
+#define Elf_Sym Elf32_Sym
+#else
+#define CURRENT_ELFCLASS ELFCLASS64
+#define Elf_Ehdr Elf64_Ehdr
+#define Elf_Shdr Elf64_Shdr
+#define Elf_Sym Elf64_Sym
+#endif
+
+static unsigned char endianness(void)
+{
+ uint16_t two_byte = 0x00FF;
+ uint8_t low_address = *((uint8_t *)&two_byte);
+
+ if (low_address == 0)
+ return ELFDATA2MSB;
+ else
+ return ELFDATA2LSB;
+}
+
+struct sym {
+ char *name;
+ unsigned long address;
+ unsigned long offset;
+ void *content;
+ int size;
+};
+
+static unsigned long get_offset_from_address(Elf_Ehdr *hdr, unsigned long addr)
+{
+ Elf_Shdr *x;
+ unsigned int i, num_sections;
+
+ x = (void *)hdr + hdr->e_shoff;
+ if (hdr->e_shnum == SHN_UNDEF)
+ num_sections = x[0].sh_size;
+ else
+ num_sections = hdr->e_shnum;
+
+ for (i = 1; i < num_sections; i++) {
+ unsigned long start = x[i].sh_addr;
+ unsigned long end = start + x[i].sh_size;
+ unsigned long offset = x[i].sh_offset;
+
+ if (addr >= start && addr <= end)
+ return addr - start + offset;
+ }
+ return 0;
+}
+
+
+#define LINE_SIZE 100
+
+static void get_symbol_from_map(Elf_Ehdr *hdr, FILE *f, char *name,
+ struct sym *s)
+{
+ char l[LINE_SIZE];
+ char *w, *p, *n;
+
+ s->size = 0;
+ s->address = 0;
+ s->offset = 0;
+ if (fseek(f, 0, SEEK_SET) != 0) {
+ perror("File seek failed");
+ exit(EXIT_FAILURE);
+ }
+ while (fgets(l, LINE_SIZE, f)) {
+ p = strchr(l, '\n');
+ if (!p) {
+ err("Missing line ending.\n");
+ return;
+ }
+ n = strstr(l, name);
+ if (n)
+ break;
+ }
+ if (!n) {
+ err("Unable to find symbol: %s\n", name);
+ return;
+ }
+ w = strchr(l, ' ');
+ if (!w)
+ return;
+
+ *w = '\0';
+ s->address = strtoul(l, NULL, 16);
+ if (s->address == 0)
+ return;
+ s->offset = get_offset_from_address(hdr, s->address);
+ s->name = name;
+ s->content = (void *)hdr + s->offset;
+}
+
+static Elf_Sym *find_elf_symbol(Elf_Ehdr *hdr, Elf_Shdr *symtab, char *name)
+{
+ Elf_Sym *sym, *symtab_start;
+ char *strtab, *symname;
+ unsigned int link;
+ Elf_Shdr *x;
+ int i, n;
+
+ x = (void *)hdr + hdr->e_shoff;
+ link = symtab->sh_link;
+ symtab_start = (void *)hdr + symtab->sh_offset;
+ n = symtab->sh_size / symtab->sh_entsize;
+ strtab = (void *)hdr + x[link].sh_offset;
+
+ for (i = 0; i < n; i++) {
+ sym = &symtab_start[i];
+ symname = strtab + sym->st_name;
+ if (strcmp(symname, name) == 0)
+ return sym;
+ }
+ err("Unable to find symbol: %s\n", name);
+ return NULL;
+}
+
+static void get_symbol_from_table(Elf_Ehdr *hdr, Elf_Shdr *symtab,
+ char *name, struct sym *s)
+{
+ Elf_Shdr *sec;
+ int secndx;
+ Elf_Sym *elf_sym;
+ Elf_Shdr *x;
+
+ x = (void *)hdr + hdr->e_shoff;
+ s->size = 0;
+ s->address = 0;
+ s->offset = 0;
+ elf_sym = find_elf_symbol(hdr, symtab, name);
+ if (!elf_sym)
+ return;
+ secndx = elf_sym->st_shndx;
+ if (!secndx)
+ return;
+ sec = &x[secndx];
+ s->size = elf_sym->st_size;
+ s->address = elf_sym->st_value;
+ s->offset = s->address - sec->sh_addr
+ + sec->sh_offset;
+ s->name = name;
+ s->content = (void *)hdr + s->offset;
+}
+
+static Elf_Shdr *get_symbol_table(Elf_Ehdr *hdr)
+{
+ Elf_Shdr *x;
+ unsigned int i, num_sections;
+
+ x = (void *)hdr + hdr->e_shoff;
+ if (hdr->e_shnum == SHN_UNDEF)
+ num_sections = x[0].sh_size;
+ else
+ num_sections = hdr->e_shnum;
+
+ for (i = 1; i < num_sections; i++)
+ if (x[i].sh_type == SHT_SYMTAB)
+ return &x[i];
+ return NULL;
+}
+
+static void *map_file(char *file_name, int *size)
+{
+ struct stat st;
+ void *map;
+ int fd;
+
+ fd = open(file_name, O_RDWR);
+ if (fd < 0) {
+ perror(file_name);
+ return NULL;
+ }
+ if (fstat(fd, &st)) {
+ perror("Could not determine file size");
+ close(fd);
+ return NULL;
+ }
+ *size = st.st_size;
+ map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+ if (map == MAP_FAILED) {
+ perror("Mapping to memory failed");
+ close(fd);
+ return NULL;
+ }
+ close(fd);
+ return map;
+}
+
+static char *read_file(char *file_name, int *size)
+{
+ struct stat st;
+ char *buf;
+ int fd;
+
+ fd = open(file_name, O_RDONLY);
+ if (fd < 0) {
+ perror(file_name);
+ return NULL;
+ }
+ if (fstat(fd, &st)) {
+ perror("Could not determine file size");
+ close(fd);
+ return NULL;
+ }
+ *size = st.st_size;
+ buf = malloc(*size);
+ if (!buf) {
+ perror("Allocating memory failed");
+ close(fd);
+ return NULL;
+ }
+ if (read(fd, buf, *size) != *size) {
+ perror("File read failed");
+ close(fd);
+ return NULL;
+ }
+ close(fd);
+ return buf;
+}
+
+static void print_sym(Elf_Ehdr *hdr, struct sym *s)
+{
+ info("sym: %s\n", s->name);
+ info("addr: 0x%lx\n", s->address);
+ info("size: %d\n", s->size);
+ info("offset: 0x%lx\n", (unsigned long)s->offset);
+}
+
+static void print_usage(char *e)
+{
+ printf("Usage %s [-s <System.map>] -b <vmlinux> -c <certfile>\n", e);
+}
+
+int main(int argc, char **argv)
+{
+ char *system_map_file = NULL;
+ char *vmlinux_file = NULL;
+ char *cert_file = NULL;
+ int vmlinux_size;
+ int cert_size;
+ Elf_Ehdr *hdr;
+ char *cert;
+ FILE *system_map;
+ unsigned long *lsize;
+ int *used;
+ int opt;
+ Elf_Shdr *symtab = NULL;
+ struct sym cert_sym, lsize_sym, used_sym;
+
+ while ((opt = getopt(argc, argv, "b:c:s:")) != -1) {
+ switch (opt) {
+ case 's':
+ system_map_file = optarg;
+ break;
+ case 'b':
+ vmlinux_file = optarg;
+ break;
+ case 'c':
+ cert_file = optarg;
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (!vmlinux_file || !cert_file) {
+ print_usage(argv[0]);
+ exit(EXIT_FAILURE);
+ }
+
+ cert = read_file(cert_file, &cert_size);
+ if (!cert)
+ exit(EXIT_FAILURE);
+
+ hdr = map_file(vmlinux_file, &vmlinux_size);
+ if (!hdr)
+ exit(EXIT_FAILURE);
+
+ if (vmlinux_size < sizeof(*hdr)) {
+ err("Invalid ELF file.\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
+ (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
+ (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
+ (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
+ err("Invalid ELF magic.\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if (hdr->e_ident[EI_CLASS] != CURRENT_ELFCLASS) {
+ err("ELF class mismatch.\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if (hdr->e_ident[EI_DATA] != endianness()) {
+ err("ELF endian mismatch.\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if (hdr->e_shoff > vmlinux_size) {
+ err("Could not find section header.\n");
+ exit(EXIT_FAILURE);
+ }
+
+ symtab = get_symbol_table(hdr);
+ if (!symtab) {
+ warn("Could not find the symbol table.\n");
+ if (!system_map_file) {
+ err("Please provide a System.map file.\n");
+ print_usage(argv[0]);
+ exit(EXIT_FAILURE);
+ }
+
+ system_map = fopen(system_map_file, "r");
+ if (!system_map) {
+ perror(system_map_file);
+ exit(EXIT_FAILURE);
+ }
+ get_symbol_from_map(hdr, system_map, CERT_SYM, &cert_sym);
+ get_symbol_from_map(hdr, system_map, USED_SYM, &used_sym);
+ get_symbol_from_map(hdr, system_map, LSIZE_SYM, &lsize_sym);
+ cert_sym.size = used_sym.address - cert_sym.address;
+ } else {
+ info("Symbol table found.\n");
+ if (system_map_file)
+ warn("System.map is ignored.\n");
+ get_symbol_from_table(hdr, symtab, CERT_SYM, &cert_sym);
+ get_symbol_from_table(hdr, symtab, USED_SYM, &used_sym);
+ get_symbol_from_table(hdr, symtab, LSIZE_SYM, &lsize_sym);
+ }
+
+ if (!cert_sym.offset || !lsize_sym.offset || !used_sym.offset)
+ exit(EXIT_FAILURE);
+
+ print_sym(hdr, &cert_sym);
+ print_sym(hdr, &used_sym);
+ print_sym(hdr, &lsize_sym);
+
+ lsize = (unsigned long *)lsize_sym.content;
+ used = (int *)used_sym.content;
+
+ if (cert_sym.size < cert_size) {
+ err("Certificate is larger than the reserved area!\n");
+ exit(EXIT_FAILURE);
+ }
+
+ /* If the existing cert is the same, don't overwrite */
+ if (cert_size == *used &&
+ strncmp(cert_sym.content, cert, cert_size) == 0) {
+ warn("Certificate was already inserted.\n");
+ exit(EXIT_SUCCESS);
+ }
+
+ if (*used > 0)
+ warn("Replacing previously inserted certificate.\n");
+
+ memcpy(cert_sym.content, cert, cert_size);
+ if (cert_size < cert_sym.size)
+ memset(cert_sym.content + cert_size,
+ 0, cert_sym.size - cert_size);
+
+ *lsize = *lsize + cert_size - *used;
+ *used = cert_size;
+ info("Inserted the contents of %s into %lx.\n", cert_file,
+ cert_sym.address);
+ info("Used %d bytes out of %d bytes reserved.\n", *used,
+ cert_sym.size);
+ exit(EXIT_SUCCESS);
+}