diff options
| -rw-r--r-- | crypto/asymmetric_keys/asymmetric_type.c | 120 | ||||
| -rw-r--r-- | include/keys/asymmetric-parser.h | 37 |
2 files changed, 156 insertions, 1 deletions
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index bfb0424..cf80765 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -11,6 +11,7 @@ * 2 of the Licence, or (at your option) any later version. */ #include <keys/asymmetric-subtype.h> +#include <keys/asymmetric-parser.h> #include <linux/seq_file.h> #include <linux/module.h> #include <linux/slab.h> @@ -18,6 +19,9 @@ MODULE_LICENSE("GPL"); +static LIST_HEAD(asymmetric_key_parsers); +static DECLARE_RWSEM(asymmetric_key_parsers_sem); + /* * Match asymmetric keys on (part of) their name * We have some shorthand methods for matching keys. We allow: @@ -107,12 +111,79 @@ static void asymmetric_key_describe(const struct key *key, struct seq_file *m) } /* + * Preparse a asymmetric payload to get format the contents appropriately for the + * internal payload to cut down on the number of scans of the data performed. + * + * We also generate a proposed description from the contents of the key that + * can be used to name the key if the user doesn't want to provide one. + */ +static int asymmetric_key_preparse(struct key_preparsed_payload *prep) +{ + struct asymmetric_key_parser *parser; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (prep->datalen == 0) + return -EINVAL; + + down_read(&asymmetric_key_parsers_sem); + + ret = -EBADMSG; + list_for_each_entry(parser, &asymmetric_key_parsers, link) { + pr_debug("Trying parser '%s'\n", parser->name); + + ret = parser->parse(prep); + if (ret != -EBADMSG) { + pr_debug("Parser recognised the format (ret %d)\n", + ret); + break; + } + } + + up_read(&asymmetric_key_parsers_sem); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +/* + * Clean up the preparse data + */ +static void asymmetric_key_free_preparse(struct key_preparsed_payload *prep) +{ + struct asymmetric_key_subtype *subtype = prep->type_data[0]; + + pr_devel("==>%s()\n", __func__); + + if (subtype) { + subtype->destroy(prep->payload); + module_put(subtype->owner); + } + kfree(prep->type_data[1]); + kfree(prep->description); +} + +/* * Instantiate a asymmetric_key defined key. The key was preparsed, so we just * have to transfer the data here. */ static int asymmetric_key_instantiate(struct key *key, struct key_preparsed_payload *prep) { - return -EOPNOTSUPP; + int ret; + + pr_devel("==>%s()\n", __func__); + + ret = key_payload_reserve(key, prep->quotalen); + if (ret == 0) { + key->type_data.p[0] = prep->type_data[0]; + key->type_data.p[1] = prep->type_data[1]; + key->payload.data = prep->payload; + prep->type_data[0] = NULL; + prep->type_data[1] = NULL; + prep->payload = NULL; + } + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; } /* @@ -132,6 +203,8 @@ static void asymmetric_key_destroy(struct key *key) struct key_type key_type_asymmetric = { .name = "asymmetric", + .preparse = asymmetric_key_preparse, + .free_preparse = asymmetric_key_free_preparse, .instantiate = asymmetric_key_instantiate, .match = asymmetric_key_match, .destroy = asymmetric_key_destroy, @@ -139,6 +212,51 @@ struct key_type key_type_asymmetric = { }; EXPORT_SYMBOL_GPL(key_type_asymmetric); +/** + * register_asymmetric_key_parser - Register a asymmetric key blob parser + * @parser: The parser to register + */ +int register_asymmetric_key_parser(struct asymmetric_key_parser *parser) +{ + struct asymmetric_key_parser *cursor; + int ret; + + down_write(&asymmetric_key_parsers_sem); + + list_for_each_entry(cursor, &asymmetric_key_parsers, link) { + if (strcmp(cursor->name, parser->name) == 0) { + pr_err("Asymmetric key parser '%s' already registered\n", + parser->name); + ret = -EEXIST; + goto out; + } + } + + list_add_tail(&parser->link, &asymmetric_key_parsers); + + pr_notice("Asymmetric key parser '%s' registered\n", parser->name); + ret = 0; + +out: + up_write(&asymmetric_key_parsers_sem); + return ret; +} +EXPORT_SYMBOL_GPL(register_asymmetric_key_parser); + +/** + * unregister_asymmetric_key_parser - Unregister a asymmetric key blob parser + * @parser: The parser to unregister + */ +void unregister_asymmetric_key_parser(struct asymmetric_key_parser *parser) +{ + down_write(&asymmetric_key_parsers_sem); + list_del(&parser->link); + up_write(&asymmetric_key_parsers_sem); + + pr_notice("Asymmetric key parser '%s' unregistered\n", parser->name); +} +EXPORT_SYMBOL_GPL(unregister_asymmetric_key_parser); + /* * Module stuff */ diff --git a/include/keys/asymmetric-parser.h b/include/keys/asymmetric-parser.h new file mode 100644 index 0000000..09b3b48 --- /dev/null +++ b/include/keys/asymmetric-parser.h @@ -0,0 +1,37 @@ +/* Asymmetric public-key cryptography data parser + * + * See Documentation/crypto/asymmetric-keys.txt + * + * Copyright (C) 2012 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. + */ + +#ifndef _KEYS_ASYMMETRIC_PARSER_H +#define _KEYS_ASYMMETRIC_PARSER_H + +/* + * Key data parser. Called during key instantiation. + */ +struct asymmetric_key_parser { + struct list_head link; + struct module *owner; + const char *name; + + /* Attempt to parse a key from the data blob passed to add_key() or + * keyctl_instantiate(). Should also generate a proposed description + * that the caller can optionally use for the key. + * + * Return EBADMSG if not recognised. + */ + int (*parse)(struct key_preparsed_payload *prep); +}; + +extern int register_asymmetric_key_parser(struct asymmetric_key_parser *); +extern void unregister_asymmetric_key_parser(struct asymmetric_key_parser *); + +#endif /* _KEYS_ASYMMETRIC_PARSER_H */ |