1 files changed, 260 insertions, 0 deletions

diff --git a/scripts/sign-file.c b/scripts/sign-file.c
new file mode 100755
index 000000000000..058bba3103e2
--- /dev/null
+++ b/scripts/sign-file.c
@@ -0,0 +1,260 @@
+/* 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/cms.h>
+#include <openssl/err.h>
+#include <openssl/engine.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)
+
+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;
+}
+
+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_cms = false, replace_orig;
+        bool sign_only = false;
+        unsigned char buf[4096];
+        unsigned long module_size, cms_size;
+        unsigned int use_keyid = 0, use_signed_attrs = CMS_NOATTR;
+        const EVP_MD *digest_algo;
+        EVP_PKEY *private_key;
+        CMS_ContentInfo *cms;
+        X509 *x509;
+        BIO *b, *bd = NULL, *bm;
+        int opt, n;
+
+        OpenSSL_add_all_algorithms();
+        ERR_load_crypto_strings();
+        ERR_clear_error();
+
+        key_pass = getenv("KBUILD_SIGN_PIN");
+
+        do {
+                opt = getopt(argc, argv, "dpk");
+                switch (opt) {
+                case 'p': save_cms = true; break;
+                case 'd': sign_only = true; save_cms = true; break;
+                case 'k': use_keyid = CMS_USE_KEYID; 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.
+         */
+        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 {
+                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);
+        }
+
+        b = BIO_new_file(x509_name, "rb");
+        ERR(!b, "%s", x509_name);
+        x509 = d2i_X509_bio(b, NULL); /* Binary encoded X.509 */
+        if (!x509) {
+                ERR(BIO_reset(b) != 1, "%s", x509_name);
+                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.
+         */
+        if (!sign_only) {
+                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 CMS 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_sign_add_signer");
+        ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) < 0,
+            "CMS_final");
+
+        if (save_cms) {
+                char *cms_name;
+
+                ERR(asprintf(&cms_name, "%s.p7s", module_name) < 0, "asprintf");
+                b = BIO_new_file(cms_name, "wb");
+                ERR(!b, "%s", cms_name);
+                ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) < 0, "%s", cms_name);
+                BIO_free(b);
+        }
+
+        if (sign_only)
+                return 0;
+
+        /* 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_CMS_bio_stream(bd, cms, NULL, 0) < 0, "%s", dest_name);
+        cms_size = BIO_number_written(bd) - module_size;
+        sig_info.sig_len = htonl(cms_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;
+}