/* Sign a module file using the given key. * * Copyright © 2014-2016 Red Hat, Inc. All Rights Reserved. * Copyright © 2015      Intel Corporation. * Copyright © 2016      Hewlett Packard Enterprise Development LP * * Authors: David Howells <dhowells@redhat.com> *          David Woodhouse <dwmw2@infradead.org> *          Juerg Haefliger <juerg.haefliger@hpe.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 2.1 * 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/opensslv.h>#include <openssl/bio.h>#include <openssl/evp.h>#include <openssl/pem.h>#include <openssl/err.h>#include <openssl/engine.h> /* * Use CMS if we have openssl-1.0.0 or newer available - otherwise we have to * assume that it's not available and its header file is missing and that we * should use PKCS#7 instead.  Switching to the older PKCS#7 format restricts * the options we have on specifying the X.509 certificate we want. * * Further, older versions of OpenSSL don't support manually adding signers to * the PKCS#7 message so have to accept that we get a certificate included in * the signature message.  Nor do such older versions of OpenSSL support * signing with anything other than SHA1 - so we're stuck with that if such is * the case. */#if defined(LIBRESSL_VERSION_NUMBER) || \	OPENSSL_VERSION_NUMBER < 0x10000000L || \	defined(OPENSSL_NO_CMS)#define USE_PKCS7#endif#ifndef USE_PKCS7#include <openssl/cms.h>#else#include <openssl/pkcs7.h>#endif 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");	fprintf(stderr,		"       scripts/sign-file -s <raw sig> <hash algo> <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) static const char *key_pass; static int pem_pw_cb(char *buf, int len, int w, void *v){	int pwlen; 	if (!key_pass)		return -1; 	pwlen = strlen(key_pass);	if (pwlen >= len)		return -1; 	strcpy(buf, key_pass); 	/* If it's wrong, don't keep trying it. */	key_pass = NULL; 	return pwlen;} static EVP_PKEY *read_private_key(const char *private_key_name){	EVP_PKEY *private_key; 	if (!strncmp(private_key_name, "pkcs11:", 7)) {		ENGINE *e; 		ENGINE_load_builtin_engines();		drain_openssl_errors();		e = ENGINE_by_id("pkcs11");		ERR(!e, "Load PKCS#11 ENGINE");		if (ENGINE_init(e))			drain_openssl_errors();		else			ERR(1, "ENGINE_init");		if (key_pass)			ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0),			    "Set PKCS#11 PIN");		private_key = ENGINE_load_private_key(e, private_key_name,						      NULL, NULL);		ERR(!private_key, "%s", private_key_name);	} else {		BIO *b; 		b = BIO_new_file(private_key_name, "rb");		ERR(!b, "%s", private_key_name);		private_key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb,						      NULL);		ERR(!private_key, "%s", private_key_name);		BIO_free(b);	} 	return private_key;} static X509 *read_x509(const char *x509_name){	unsigned char buf[2];	X509 *x509;	BIO *b;	int n; 	b = BIO_new_file(x509_name, "rb");	ERR(!b, "%s", x509_name); 	/* Look at the first two bytes of the file to determine the encoding */	n = BIO_read(b, buf, 2);	if (n != 2) {		if (BIO_should_retry(b)) {			fprintf(stderr, "%s: Read wanted retry\n", x509_name);			exit(1);		}		if (n >= 0) {			fprintf(stderr, "%s: Short read\n", x509_name);			exit(1);		}		ERR(1, "%s", x509_name);	} 	ERR(BIO_reset(b) != 0, "%s", x509_name); 	if (buf[0] == 0x30 && buf[1] >= 0x81 && buf[1] <= 0x84)		/* Assume raw DER encoded X.509 */		x509 = d2i_X509_bio(b, NULL);	else		/* Assume PEM encoded X.509 */		x509 = PEM_read_bio_X509(b, NULL, NULL, NULL); 	BIO_free(b);	ERR(!x509, "%s", x509_name); 	return x509;} int main(int argc, char **argv){	struct module_signature sig_info = { .id_type = PKEY_ID_PKCS7 };	char *hash_algo = NULL;	char *private_key_name = NULL, *raw_sig_name = NULL;	char *x509_name, *module_name, *dest_name;	bool save_sig = false, replace_orig;	bool sign_only = false;	bool raw_sig = false;	unsigned char buf[4096];	unsigned long module_size, sig_size;	unsigned int use_signed_attrs;	const EVP_MD *digest_algo;	EVP_PKEY *private_key;#ifndef USE_PKCS7	CMS_ContentInfo *cms = NULL;	unsigned int use_keyid = 0;#else	PKCS7 *pkcs7 = NULL;#endif	X509 *x509;	BIO *bd, *bm;	int opt, n;	OpenSSL_add_all_algorithms();	ERR_load_crypto_strings();	ERR_clear_error(); 	key_pass = getenv("KBUILD_SIGN_PIN"); #ifndef USE_PKCS7	use_signed_attrs = CMS_NOATTR;#else	use_signed_attrs = PKCS7_NOATTR;#endif 	do {		opt = getopt(argc, argv, "sdpk");		switch (opt) {		case 's': raw_sig = true; break;		case 'p': save_sig = true; break;		case 'd': sign_only = true; save_sig = true; break;#ifndef USE_PKCS7		case 'k': use_keyid = CMS_USE_KEYID; break;#endif		case -1: break;		default: format();		}	} while (opt != -1); 	argc -= optind;	argv += optind;	if (argc < 4 || argc > 5)		format(); 	if (raw_sig) {		raw_sig_name = argv[0];		hash_algo = argv[1];	} else {		hash_algo = argv[0];		private_key_name = argv[1];	}	x509_name = argv[2];	module_name = argv[3];	if (argc == 5 && strcmp(argv[3], argv[4]) != 0) {		dest_name = argv[4];		replace_orig = false;	} else {		ERR(asprintf(&dest_name, "%s.~signed~", module_name) < 0,		    "asprintf");		replace_orig = true;	} #ifdef USE_PKCS7	if (strcmp(hash_algo, "sha1") != 0) {		fprintf(stderr, "sign-file: %s only supports SHA1 signing\n",			OPENSSL_VERSION_TEXT);		exit(3);	}#endif 	/* Open the module file */	bm = BIO_new_file(module_name, "rb");	ERR(!bm, "%s", module_name); 	if (!raw_sig) {		/* Read the private key and the X.509 cert the PKCS#7 message		 * will point to.		 */		private_key = read_private_key(private_key_name);		x509 = read_x509(x509_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"); #ifndef USE_PKCS7		/* Load the signature message from the digest buffer. */		cms = CMS_sign(NULL, NULL, NULL, NULL,			       CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY |			       CMS_DETACHED | CMS_STREAM);		ERR(!cms, "CMS_sign"); 		ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo,				     CMS_NOCERTS | CMS_BINARY |				     CMS_NOSMIMECAP | use_keyid |				     use_signed_attrs),		    "CMS_add1_signer");		ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) < 0,		    "CMS_final"); #else		pkcs7 = PKCS7_sign(x509, private_key, NULL, bm,				   PKCS7_NOCERTS | PKCS7_BINARY |				   PKCS7_DETACHED | use_signed_attrs);		ERR(!pkcs7, "PKCS7_sign");#endif 		if (save_sig) {			char *sig_file_name;			BIO *b; 			ERR(asprintf(&sig_file_name, "%s.p7s", module_name) < 0,			    "asprintf");			b = BIO_new_file(sig_file_name, "wb");			ERR(!b, "%s", sig_file_name);#ifndef USE_PKCS7			ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) < 0,			    "%s", sig_file_name);#else			ERR(i2d_PKCS7_bio(b, pkcs7) < 0,			    "%s", sig_file_name);#endif			BIO_free(b);		} 		if (sign_only) {			BIO_free(bm);			return 0;		}	} 	/* 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); 	/* 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);	}	BIO_free(bm);	ERR(n < 0, "%s", module_name);	module_size = BIO_number_written(bd); 	if (!raw_sig) {#ifndef USE_PKCS7		ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) < 0, "%s", dest_name);#else		ERR(i2d_PKCS7_bio(bd, pkcs7) < 0, "%s", dest_name);#endif	} else {		BIO *b; 		/* Read the raw signature file and write the data to the		 * destination file		 */		b = BIO_new_file(raw_sig_name, "rb");		ERR(!b, "%s", raw_sig_name);		while ((n = BIO_read(b, buf, sizeof(buf))), n > 0)			ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name);		BIO_free(b);	} 	sig_size = BIO_number_written(bd) - module_size;	sig_info.sig_len = htonl(sig_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;}