| /* Testing module to load key from trusted PKCS#7 message |
| * |
| * 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 pr_fmt(fmt) "PKCS7key: "fmt |
| #include <linux/key.h> |
| #include <linux/err.h> |
| #include <linux/module.h> |
| #include <linux/key-type.h> |
| #include <keys/asymmetric-type.h> |
| #include <crypto/pkcs7.h> |
| #include <keys/user-type.h> |
| #include <keys/system_keyring.h> |
| #include "pkcs7_parser.h" |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("PKCS#7 testing key type"); |
| |
| static unsigned pkcs7_usage; |
| module_param_named(usage, pkcs7_usage, uint, S_IWUSR | S_IRUGO); |
| MODULE_PARM_DESC(pkcs7_usage, |
| "Usage to specify when verifying the PKCS#7 message"); |
| |
| /* |
| * Preparse a PKCS#7 wrapped and validated data blob. |
| */ |
| static int pkcs7_preparse(struct key_preparsed_payload *prep) |
| { |
| enum key_being_used_for usage = pkcs7_usage; |
| struct pkcs7_message *pkcs7; |
| const void *data, *saved_prep_data; |
| size_t datalen, saved_prep_datalen; |
| bool trusted; |
| int ret; |
| |
| kenter(""); |
| |
| if (usage >= NR__KEY_BEING_USED_FOR) { |
| pr_err("Invalid usage type %d\n", usage); |
| return -EINVAL; |
| } |
| |
| saved_prep_data = prep->data; |
| saved_prep_datalen = prep->datalen; |
| pkcs7 = pkcs7_parse_message(saved_prep_data, saved_prep_datalen); |
| if (IS_ERR(pkcs7)) { |
| ret = PTR_ERR(pkcs7); |
| goto error; |
| } |
| |
| ret = pkcs7_verify(pkcs7, usage); |
| if (ret < 0) |
| goto error_free; |
| |
| ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted); |
| if (ret < 0) |
| goto error_free; |
| if (!trusted) |
| pr_warn("PKCS#7 message doesn't chain back to a trusted key\n"); |
| |
| ret = pkcs7_get_content_data(pkcs7, &data, &datalen, false); |
| if (ret < 0) |
| goto error_free; |
| |
| prep->data = data; |
| prep->datalen = datalen; |
| ret = user_preparse(prep); |
| prep->data = saved_prep_data; |
| prep->datalen = saved_prep_datalen; |
| |
| error_free: |
| pkcs7_free_message(pkcs7); |
| error: |
| kleave(" = %d", ret); |
| return ret; |
| } |
| |
| /* |
| * user defined keys take an arbitrary string as the description and an |
| * arbitrary blob of data as the payload |
| */ |
| static struct key_type key_type_pkcs7 = { |
| .name = "pkcs7_test", |
| .preparse = pkcs7_preparse, |
| .free_preparse = user_free_preparse, |
| .instantiate = generic_key_instantiate, |
| .revoke = user_revoke, |
| .destroy = user_destroy, |
| .describe = user_describe, |
| .read = user_read, |
| }; |
| |
| /* |
| * Module stuff |
| */ |
| static int __init pkcs7_key_init(void) |
| { |
| return register_key_type(&key_type_pkcs7); |
| } |
| |
| static void __exit pkcs7_key_cleanup(void) |
| { |
| unregister_key_type(&key_type_pkcs7); |
| } |
| |
| module_init(pkcs7_key_init); |
| module_exit(pkcs7_key_cleanup); |