diff options
Diffstat (limited to 'scripts/sign-file.c')
| -rwxr-xr-x | scripts/sign-file.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/scripts/sign-file.c b/scripts/sign-file.c new file mode 100755 index 000000000000..5b8a6dda3235 --- /dev/null +++ b/scripts/sign-file.c @@ -0,0 +1,205 @@ +/* Sign a module file using the given key. + * + * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#define _GNU_SOURCE +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <stdbool.h> +#include <string.h> +#include <getopt.h> +#include <err.h> +#include <arpa/inet.h> +#include <openssl/bio.h> +#include <openssl/evp.h> +#include <openssl/pem.h> +#include <openssl/pkcs7.h> +#include <openssl/err.h> + +struct module_signature { + uint8_t algo; /* Public-key crypto algorithm [0] */ + uint8_t hash; /* Digest algorithm [0] */ + uint8_t id_type; /* Key identifier type [PKEY_ID_PKCS7] */ + uint8_t signer_len; /* Length of signer's name [0] */ + uint8_t key_id_len; /* Length of key identifier [0] */ + uint8_t __pad[3]; + uint32_t sig_len; /* Length of signature data */ +}; + +#define PKEY_ID_PKCS7 2 + +static char magic_number[] = "~Module signature appended~\n"; + +static __attribute__((noreturn)) +void format(void) +{ + fprintf(stderr, + "Usage: scripts/sign-file [-dp] <hash algo> <key> <x509> <module> [<dest>]\n"); + exit(2); +} + +static void display_openssl_errors(int l) +{ + const char *file; + char buf[120]; + int e, line; + + if (ERR_peek_error() == 0) + return; + fprintf(stderr, "At main.c:%d:\n", l); + + while ((e = ERR_get_error_line(&file, &line))) { + ERR_error_string(e, buf); + fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line); + } +} + +static void drain_openssl_errors(void) +{ + const char *file; + int line; + + if (ERR_peek_error() == 0) + return; + while (ERR_get_error_line(&file, &line)) {} +} + +#define ERR(cond, fmt, ...) \ + do { \ + bool __cond = (cond); \ + display_openssl_errors(__LINE__); \ + if (__cond) { \ + err(1, fmt, ## __VA_ARGS__); \ + } \ + } while(0) + +int main(int argc, char **argv) +{ + struct module_signature sig_info = { .id_type = PKEY_ID_PKCS7 }; + char *hash_algo = NULL; + char *private_key_name, *x509_name, *module_name, *dest_name; + bool save_pkcs7 = false, replace_orig; + unsigned char buf[4096]; + unsigned long module_size, pkcs7_size; + const EVP_MD *digest_algo; + EVP_PKEY *private_key; + PKCS7 *pkcs7; + X509 *x509; + BIO *b, *bd, *bm; + int opt, n; + + ERR_load_crypto_strings(); + ERR_clear_error(); + + do { + opt = getopt(argc, argv, "dp"); + switch (opt) { + case 'p': save_pkcs7 = true; break; + case -1: break; + default: format(); + } + } while (opt != -1); + + argc -= optind; + argv += optind; + if (argc < 4 || argc > 5) + format(); + + hash_algo = argv[0]; + private_key_name = argv[1]; + x509_name = argv[2]; + module_name = argv[3]; + if (argc == 5) { + dest_name = argv[4]; + replace_orig = false; + } else { + ERR(asprintf(&dest_name, "%s.~signed~", module_name) < 0, + "asprintf"); + replace_orig = true; + } + + /* Read the private key and the X.509 cert the PKCS#7 message + * will point to. + */ + b = BIO_new_file(private_key_name, "rb"); + ERR(!b, "%s", private_key_name); + private_key = PEM_read_bio_PrivateKey(b, NULL, NULL, NULL); + BIO_free(b); + + b = BIO_new_file(x509_name, "rb"); + ERR(!b, "%s", x509_name); + x509 = d2i_X509_bio(b, NULL); /* Binary encoded X.509 */ + if (!x509) { + BIO_reset(b); + x509 = PEM_read_bio_X509(b, NULL, NULL, NULL); /* PEM encoded X.509 */ + if (x509) + drain_openssl_errors(); + } + BIO_free(b); + ERR(!x509, "%s", x509_name); + + /* Open the destination file now so that we can shovel the module data + * across as we read it. + */ + bd = BIO_new_file(dest_name, "wb"); + ERR(!bd, "%s", dest_name); + + /* Digest the module data. */ + OpenSSL_add_all_digests(); + display_openssl_errors(__LINE__); + digest_algo = EVP_get_digestbyname(hash_algo); + ERR(!digest_algo, "EVP_get_digestbyname"); + + bm = BIO_new_file(module_name, "rb"); + ERR(!bm, "%s", module_name); + + /* Load the PKCS#7 message from the digest buffer. */ + pkcs7 = PKCS7_sign(NULL, NULL, NULL, NULL, + PKCS7_NOCERTS | PKCS7_PARTIAL | PKCS7_BINARY | PKCS7_DETACHED | PKCS7_STREAM); + ERR(!pkcs7, "PKCS7_sign"); + + ERR(!PKCS7_sign_add_signer(pkcs7, x509, private_key, digest_algo, PKCS7_NOCERTS | PKCS7_BINARY), + "PKCS7_sign_add_signer"); + ERR(PKCS7_final(pkcs7, bm, PKCS7_NOCERTS | PKCS7_BINARY) < 0, + "PKCS7_final"); + + if (save_pkcs7) { + char *pkcs7_name; + + ERR(asprintf(&pkcs7_name, "%s.pkcs7", module_name) < 0, "asprintf"); + b = BIO_new_file(pkcs7_name, "wb"); + ERR(!b, "%s", pkcs7_name); + ERR(i2d_PKCS7_bio_stream(b, pkcs7, NULL, 0) < 0, "%s", pkcs7_name); + BIO_free(b); + } + + /* Append the marker and the PKCS#7 message to the destination file */ + ERR(BIO_reset(bm) < 0, "%s", module_name); + while ((n = BIO_read(bm, buf, sizeof(buf))), + n > 0) { + ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name); + } + ERR(n < 0, "%s", module_name); + module_size = BIO_number_written(bd); + + ERR(i2d_PKCS7_bio_stream(bd, pkcs7, NULL, 0) < 0, "%s", dest_name); + pkcs7_size = BIO_number_written(bd) - module_size; + sig_info.sig_len = htonl(pkcs7_size); + ERR(BIO_write(bd, &sig_info, sizeof(sig_info)) < 0, "%s", dest_name); + ERR(BIO_write(bd, magic_number, sizeof(magic_number) - 1) < 0, "%s", dest_name); + + ERR(BIO_free(bd) < 0, "%s", dest_name); + + /* Finally, if we're signing in place, replace the original. */ + if (replace_orig) + ERR(rename(dest_name, module_name) < 0, "%s", dest_name); + + return 0; +} |