scripts/extract-cert.c

   1 /* Extract X.509 certificate in DER form from PKCS#11 or PEM.
   2  *
   3  * Copyright © 2014 Red Hat, Inc. All Rights Reserved.
   4  * Copyright © 2015 Intel Corporation.
   5  *
   6  * Authors: David Howells <dhowells@redhat.com>
   7  *          David Woodhouse <dwmw2@infradead.org>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public Licence
  11  * as published by the Free Software Foundation; either version
  12  * 2 of the Licence, or (at your option) any later version.
  13  */
  14 #define _GNU_SOURCE
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <stdint.h>
  18 #include <stdbool.h>
  19 #include <string.h>
  20 #include <getopt.h>
  21 #include <err.h>
  22 #include <arpa/inet.h>
  23 #include <openssl/bio.h>
  24 #include <openssl/evp.h>
  25 #include <openssl/pem.h>
  26 #include <openssl/pkcs7.h>
  27 #include <openssl/err.h>
  28 #include <openssl/engine.h>
  29
  30 #define PKEY_ID_PKCS7 2
  31
  32 static __attribute__((noreturn))
  33 void format(void)
  34 {
  35         fprintf(stderr,
  36                 "Usage: scripts/extract-cert <source> <dest>\n");
  37         exit(2);
  38 }
  39
  40 static void display_openssl_errors(int l)
  41 {
  42         const char *file;
  43         char buf[120];
  44         int e, line;
  45
  46         if (ERR_peek_error() == 0)
  47                 return;
  48         fprintf(stderr, "At main.c:%d:\n", l);
  49
  50         while ((e = ERR_get_error_line(&file, &line))) {
  51                 ERR_error_string(e, buf);
  52                 fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
  53         }
  54 }
  55
  56 static void drain_openssl_errors(void)
  57 {
  58         const char *file;
  59         int line;
  60
  61         if (ERR_peek_error() == 0)
  62                 return;
  63         while (ERR_get_error_line(&file, &line)) {}
  64 }
  65
  66 #define ERR(cond, fmt, ...)                             \
  67         do {                                            \
  68                 bool __cond = (cond);                   \
  69                 display_openssl_errors(__LINE__);       \
  70                 if (__cond) {                           \
  71                         err(1, fmt, ## __VA_ARGS__);    \
  72                 }                                       \
  73         } while(0)
  74
  75 static const char *key_pass;
  76
  77 int main(int argc, char **argv)
  78 {
  79         char *cert_src, *cert_dst;
  80         X509 *x509;
  81         BIO *b;
  82
  83         OpenSSL_add_all_algorithms();
  84         ERR_load_crypto_strings();
  85         ERR_clear_error();
  86
  87         key_pass = getenv("KBUILD_SIGN_PIN");
  88
  89         if (argc != 3)
  90                 format();
  91
  92         cert_src = argv[1];
  93         cert_dst = argv[2];
  94
  95         if (!strncmp(cert_src, "pkcs11:", 7)) {
  96                 ENGINE *e;
  97                 struct {
  98                         const char *cert_id;
  99                         X509 *cert;
 100                 } parms;
 101
 102                 parms.cert_id = cert_src;
 103                 parms.cert = NULL;
 104
 105                 ENGINE_load_builtin_engines();
 106                 drain_openssl_errors();
 107                 e = ENGINE_by_id("pkcs11");
 108                 ERR(!e, "Load PKCS#11 ENGINE");
 109                 if (ENGINE_init(e))
 110                         drain_openssl_errors();
 111                 else
 112                         ERR(1, "ENGINE_init");
 113                 if (key_pass)
 114                         ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN");
 115                 ENGINE_ctrl_cmd(e, "LOAD_CERT_CTRL", 0, &parms, NULL, 1);
 116                 ERR(!parms.cert, "Get X.509 from PKCS#11");
 117                 x509 = parms.cert;
 118         } else {
 119                 b = BIO_new_file(cert_src, "rb");
 120                 ERR(!b, "%s", cert_src);
 121                 x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
 122                 ERR(!x509, "%s", cert_src);
 123                 BIO_free(b);
 124         }
 125
 126         b = BIO_new_file(cert_dst, "wb");
 127         ERR(!b, "%s", cert_dst);
 128         ERR(!i2d_X509_bio(b, x509), cert_dst);
 129         BIO_free(b);
 130
 131         return 0;
 132 }