From patchwork Thu Jul 22 09:17:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 12393515 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C4FDC63798 for ; Thu, 22 Jul 2021 09:18:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 288E26101B for ; Thu, 22 Jul 2021 09:18:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230504AbhGVIiF (ORCPT ); Thu, 22 Jul 2021 04:38:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231387AbhGVIh6 (ORCPT ); Thu, 22 Jul 2021 04:37:58 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A27DC061575 for ; Thu, 22 Jul 2021 02:18:34 -0700 (PDT) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1m6UqE-0001NL-VW; Thu, 22 Jul 2021 11:18:06 +0200 Received: from afa by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1m6UqC-0001Cm-EB; Thu, 22 Jul 2021 11:18:04 +0200 From: Ahmad Fatoum To: David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Song Liu , Richard Weinberger Cc: kernel@pengutronix.de, Ahmad Fatoum , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org Subject: [RFC PATCH v1 1/4] keys: introduce key_extract_material helper Date: Thu, 22 Jul 2021 11:17:59 +0200 Message-Id: X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: afa@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org Precedence: bulk List-ID: While keys of differing type have a common struct key definition, there is no common scheme to the payload and key material extraction differs. For kernel functionality that supports different key types, this means duplicated code for key material extraction and because key type is discriminated by a pointer to a global, users need to replicate reachability checks as well, so builtin code doesn't depend on a key type symbol offered by a module. Make this easier by adding a common helper with initial support for user, logon, encrypted and trusted keys. The code is taken from dm-crypt, which is migrated to use the helper in a later commit. The implementation must be partially in a header to support configurations where the key type symbol is defined in a module, but key support in general is built-in. Signed-off-by: Ahmad Fatoum --- I am not sure whether the chosen header and source file are the best places for this. This could be made header-only too if that's preferred. To: David Howells To: Jarkko Sakkinen To: James Morris To: "Serge E. Hallyn" To: Alasdair Kergon To: Mike Snitzer To: dm-devel@redhat.com To: Song Liu To: Richard Weinberger Cc: linux-kernel@vger.kernel.org Cc: linux-raid@vger.kernel.org Cc: keyrings@vger.kernel.org Cc: linux-mtd@lists.infradead.org Cc: linux-security-module@vger.kernel.org Cc: linux-integrity@vger.kernel.org --- include/linux/key.h | 45 +++++++++++++++++++++++++++++++++++++++++++++ security/keys/key.c | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 85 insertions(+) diff --git a/include/linux/key.h b/include/linux/key.h index 7febc4881363..916612f5b313 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -20,6 +20,8 @@ #include #include #include +#include +#include #ifdef __KERNEL__ #include @@ -487,6 +489,48 @@ extern void key_fsuid_changed(struct cred *new_cred); extern void key_fsgid_changed(struct cred *new_cred); extern void key_init(void); +/* + * internal use, so key core code need not link against + * all supported key types + * */ +enum __key_type { + KEY_TYPE_UNKNOWN, KEY_TYPE_USER, KEY_TYPE_ENCRYPTED, KEY_TYPE_TRUSTED +}; + +const void *__key_extract_material(const struct key *key, enum __key_type type, + unsigned int *len); + +/** + * key_extract_material - Extract decrypted data out of a key + * @key: a logon, user, encrypted or trusted key + * @len: pointer to variable to store key size into + * + * Extract decrypted data out of supported key types + * + * Returns a pointer to the key material if successfull or an error + * pointer if key type is not compiled in, the buffer is too + * small or the key was revoked. + */ +static inline const void *key_extract_material(const struct key *key, + unsigned int *len) +{ + extern struct key_type key_type_user; + extern struct key_type key_type_logon; + extern struct key_type key_type_encrypted; + extern struct key_type key_type_trusted; + enum __key_type type = KEY_TYPE_UNKNOWN; + const struct key_type *t = key->type; + + if (t == &key_type_logon || t == &key_type_user) + type = KEY_TYPE_USER; + else if (IS_REACHABLE(CONFIG_ENCRYPTED_KEYS) && t == &key_type_encrypted) + type = KEY_TYPE_ENCRYPTED; + else if (IS_REACHABLE(CONFIG_TRUSTED_KEYS) && t == &key_type_trusted) + type = KEY_TYPE_TRUSTED; + + return __key_extract_material(key, type, len); +} + #else /* CONFIG_KEYS */ #define key_validate(k) 0 @@ -504,6 +548,7 @@ extern void key_init(void); #define key_init() do { } while(0) #define key_free_user_ns(ns) do { } while(0) #define key_remove_domain(d) do { } while(0) +#define key_extract_material(k, l) ERR_PTR(-EINVAL) #endif /* CONFIG_KEYS */ #endif /* __KERNEL__ */ diff --git a/security/keys/key.c b/security/keys/key.c index c45afdd1dfbb..69cd1cb8c413 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -15,6 +15,9 @@ #include #include #include +#include +#include +#include #include "internal.h" struct kmem_cache *key_jar; @@ -1140,6 +1143,43 @@ int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep) } EXPORT_SYMBOL(generic_key_instantiate); +const void *__key_extract_material(const struct key *key, + enum __key_type type, unsigned int *len) +{ + const struct encrypted_key_payload *ekp; + const struct trusted_key_payload *tkp; + const struct user_key_payload *ukp; + + switch (type) { + case KEY_TYPE_USER: + ukp = user_key_payload_locked(key); + if (!ukp) + break; + + *len = ukp->datalen; + return ukp->data; + case KEY_TYPE_ENCRYPTED: + ekp = key->payload.data[0]; + if (!ekp) + break; + + *len = ekp->decrypted_datalen; + return ekp->decrypted_data; + case KEY_TYPE_TRUSTED: + tkp = key->payload.data[0]; + if (!tkp) + break; + + *len = tkp->key_len; + return tkp->key; + default: + return ERR_PTR(-EINVAL); + } + + return ERR_PTR(-EKEYREVOKED); +} +EXPORT_SYMBOL(__key_extract_material); + /** * register_key_type - Register a type of key. * @ktype: The new key type. From patchwork Thu Jul 22 09:18:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 12393517 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4054C6377D for ; Thu, 22 Jul 2021 09:19:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A52C76101B for ; Thu, 22 Jul 2021 09:19:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231442AbhGVIik (ORCPT ); Thu, 22 Jul 2021 04:38:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231452AbhGVIiG (ORCPT ); Thu, 22 Jul 2021 04:38:06 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1C44C0613D3 for ; Thu, 22 Jul 2021 02:18:41 -0700 (PDT) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1m6UqE-0001NM-VX; Thu, 22 Jul 2021 11:18:06 +0200 Received: from afa by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1m6UqC-0001Cr-FA; Thu, 22 Jul 2021 11:18:04 +0200 From: Ahmad Fatoum To: David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Song Liu , Richard Weinberger Cc: kernel@pengutronix.de, Ahmad Fatoum , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org Subject: [RFC PATCH v1 2/4] dm: crypt: use new key_extract_material helper Date: Thu, 22 Jul 2021 11:18:00 +0200 Message-Id: <7ac4a9ae0a3c2dfdf41611f3fe78fe63a6e57b94.1626945419.git-series.a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: afa@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org Precedence: bulk List-ID: There is a common function now to extract key material out of a few different key types, which includes all types currently supported by dm-crypt. Make use of it. Signed-off-by: Ahmad Fatoum --- To: David Howells To: Jarkko Sakkinen To: James Morris To: "Serge E. Hallyn" To: Alasdair Kergon To: Mike Snitzer To: dm-devel@redhat.com To: Song Liu To: Richard Weinberger Cc: linux-kernel@vger.kernel.org Cc: linux-raid@vger.kernel.org Cc: keyrings@vger.kernel.org Cc: linux-mtd@lists.infradead.org Cc: linux-security-module@vger.kernel.org Cc: linux-integrity@vger.kernel.org --- drivers/md/dm-crypt.c | 65 ++++++-------------------------------------- 1 file changed, 9 insertions(+), 56 deletions(-) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 50f4cbd600d5..576d6b7ce231 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -2421,61 +2421,14 @@ static bool contains_whitespace(const char *str) return false; } -static int set_key_user(struct crypt_config *cc, struct key *key) -{ - const struct user_key_payload *ukp; - - ukp = user_key_payload_locked(key); - if (!ukp) - return -EKEYREVOKED; - - if (cc->key_size != ukp->datalen) - return -EINVAL; - - memcpy(cc->key, ukp->data, cc->key_size); - - return 0; -} - -static int set_key_encrypted(struct crypt_config *cc, struct key *key) -{ - const struct encrypted_key_payload *ekp; - - ekp = key->payload.data[0]; - if (!ekp) - return -EKEYREVOKED; - - if (cc->key_size != ekp->decrypted_datalen) - return -EINVAL; - - memcpy(cc->key, ekp->decrypted_data, cc->key_size); - - return 0; -} - -static int set_key_trusted(struct crypt_config *cc, struct key *key) -{ - const struct trusted_key_payload *tkp; - - tkp = key->payload.data[0]; - if (!tkp) - return -EKEYREVOKED; - - if (cc->key_size != tkp->key_len) - return -EINVAL; - - memcpy(cc->key, tkp->key, cc->key_size); - - return 0; -} - static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) { char *new_key_string, *key_desc; int ret; + unsigned int len; struct key_type *type; struct key *key; - int (*set_key)(struct crypt_config *cc, struct key *key); + const void *key_material; /* * Reject key_string with whitespace. dm core currently lacks code for @@ -2493,18 +2446,14 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) { type = &key_type_logon; - set_key = set_key_user; } else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) { type = &key_type_user; - set_key = set_key_user; } else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) && !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) { type = &key_type_encrypted; - set_key = set_key_encrypted; } else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) && !strncmp(key_string, "trusted:", key_desc - key_string + 1)) { type = &key_type_trusted; - set_key = set_key_trusted; } else { return -EINVAL; } @@ -2521,14 +2470,18 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string down_read(&key->sem); - ret = set_key(cc, key); - if (ret < 0) { + key_material = key_extract_material(key, &len); + if (!IS_ERR(key_material) && len != cc->key_size) + key_material = ERR_PTR(-EINVAL); + if (IS_ERR(key_material)) { up_read(&key->sem); key_put(key); kfree_sensitive(new_key_string); - return ret; + return PTR_ERR(key_material); } + memcpy(cc->key, key_material, len); + up_read(&key->sem); key_put(key); From patchwork Thu Jul 22 09:18:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 12393509 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42AB5C63797 for ; Thu, 22 Jul 2021 09:18:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 301776101B for ; Thu, 22 Jul 2021 09:18:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231408AbhGVIiB (ORCPT ); Thu, 22 Jul 2021 04:38:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231351AbhGVIhz (ORCPT ); Thu, 22 Jul 2021 04:37:55 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 733FBC0613C1 for ; Thu, 22 Jul 2021 02:18:30 -0700 (PDT) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1m6UqE-0001NN-VX; Thu, 22 Jul 2021 11:18:06 +0200 Received: from afa by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1m6UqC-0001Cw-GC; Thu, 22 Jul 2021 11:18:04 +0200 From: Ahmad Fatoum To: David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Song Liu , Richard Weinberger Cc: kernel@pengutronix.de, Ahmad Fatoum , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org Subject: [RFC PATCH v1 3/4] ubifs: auth: remove never hit key type error check Date: Thu, 22 Jul 2021 11:18:01 +0200 Message-Id: X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: afa@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org Precedence: bulk List-ID: key_request accepts a key type as its first argument. If it returns a valid pointer, it should always have this same requested key type. Indeed other request_key users surveyed such as dm-crypt, ecryptfs and fscrypt v1 also don't check the key type. Therefore drop the apparently unneeded check. Signed-off-by: Ahmad Fatoum --- To: David Howells To: Jarkko Sakkinen To: James Morris To: "Serge E. Hallyn" To: Alasdair Kergon To: Mike Snitzer To: dm-devel@redhat.com To: Song Liu To: Richard Weinberger Cc: linux-kernel@vger.kernel.org Cc: linux-raid@vger.kernel.org Cc: keyrings@vger.kernel.org Cc: linux-mtd@lists.infradead.org Cc: linux-security-module@vger.kernel.org Cc: linux-integrity@vger.kernel.org --- fs/ubifs/auth.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/fs/ubifs/auth.c b/fs/ubifs/auth.c index e564d5ff8781..6a0b8d858d81 100644 --- a/fs/ubifs/auth.c +++ b/fs/ubifs/auth.c @@ -286,12 +286,6 @@ int ubifs_init_authentication(struct ubifs_info *c) down_read(&keyring_key->sem); - if (keyring_key->type != &key_type_logon) { - ubifs_err(c, "key type must be logon"); - err = -ENOKEY; - goto out; - } - ukp = user_key_payload_locked(keyring_key); if (!ukp) { /* key was revoked before we acquired its semaphore */ From patchwork Thu Jul 22 09:18:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 12393513 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C2C2C6377D for ; Thu, 22 Jul 2021 09:18:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 755026124B for ; Thu, 22 Jul 2021 09:18:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231272AbhGVIiE (ORCPT ); Thu, 22 Jul 2021 04:38:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231378AbhGVIh6 (ORCPT ); Thu, 22 Jul 2021 04:37:58 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D219C061757 for ; Thu, 22 Jul 2021 02:18:33 -0700 (PDT) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1m6UqF-0001NO-DL; Thu, 22 Jul 2021 11:18:07 +0200 Received: from afa by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1m6UqC-0001D1-HE; Thu, 22 Jul 2021 11:18:04 +0200 From: Ahmad Fatoum To: David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Song Liu , Richard Weinberger , Jonathan Corbet Cc: kernel@pengutronix.de, Ahmad Fatoum , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-raid@vger.kernel.org, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org Subject: [RFC PATCH v1 4/4] ubifs: auth: consult encrypted and trusted keys if no logon key was found Date: Thu, 22 Jul 2021 11:18:02 +0200 Message-Id: X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: afa@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org Precedence: bulk List-ID: Currently, UBIFS auth_key can only be a logon key: This is a user key that's provided to the kernel in plaintext and that then remains within the kernel. Linux also supports trusted and encrypted keys, which have stronger guarantees: They are only exposed to userspace in encrypted form and, in the case of trusted keys, can be directly rooted to a trust source like a TPM chip. Add support for auth_key to be either a logon, encrypted or trusted key. At mount time, the keyring will be searched for a key with the supplied name in that order. Signed-off-by: Ahmad Fatoum --- To: David Howells To: Jarkko Sakkinen To: James Morris To: "Serge E. Hallyn" To: Alasdair Kergon To: Mike Snitzer To: dm-devel@redhat.com To: Song Liu To: Richard Weinberger To: Jonathan Corbet Cc: linux-kernel@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-raid@vger.kernel.org Cc: keyrings@vger.kernel.org Cc: linux-mtd@lists.infradead.org Cc: linux-security-module@vger.kernel.org Cc: linux-integrity@vger.kernel.org --- Documentation/filesystems/ubifs.rst | 2 +- fs/ubifs/auth.c | 19 ++++++++++++------- 2 files changed, 13 insertions(+), 8 deletions(-) diff --git a/Documentation/filesystems/ubifs.rst b/Documentation/filesystems/ubifs.rst index e6ee99762534..12d08458b3d7 100644 --- a/Documentation/filesystems/ubifs.rst +++ b/Documentation/filesystems/ubifs.rst @@ -101,7 +101,7 @@ compr=zlib override default compressor and set it to "zlib" auth_key= specify the key used for authenticating the filesystem. Passing this option makes authentication mandatory. The passed key must be present in the kernel keyring - and must be of type 'logon' + and must be of type 'logon', 'encrypted' or 'trusted'. auth_hash_name= The hash algorithm used for authentication. Used for both hashing and for creating HMACs. Typical values include "sha256" or "sha512" diff --git a/fs/ubifs/auth.c b/fs/ubifs/auth.c index 6a0b8d858d81..af8e9eb58a60 100644 --- a/fs/ubifs/auth.c +++ b/fs/ubifs/auth.c @@ -14,6 +14,8 @@ #include #include #include +#include +#include #include #include "ubifs.h" @@ -256,9 +258,10 @@ out_destroy: int ubifs_init_authentication(struct ubifs_info *c) { struct key *keyring_key; - const struct user_key_payload *ukp; int err; + unsigned int len; char hmac_name[CRYPTO_MAX_ALG_NAME]; + const void *key_material; if (!c->auth_hash_name) { ubifs_err(c, "authentication hash name needed with authentication"); @@ -277,6 +280,10 @@ int ubifs_init_authentication(struct ubifs_info *c) c->auth_hash_name); keyring_key = request_key(&key_type_logon, c->auth_key_name, NULL); + if (IS_ERR(keyring_key) && IS_REACHABLE(CONFIG_ENCRYPTED_KEYS)) + keyring_key = request_key(&key_type_encrypted, c->auth_key_name, NULL); + if (IS_ERR(keyring_key) && IS_REACHABLE(CONFIG_TRUSTED_KEYS)) + keyring_key = request_key(&key_type_trusted, c->auth_key_name, NULL); if (IS_ERR(keyring_key)) { ubifs_err(c, "Failed to request key: %ld", @@ -286,12 +293,10 @@ int ubifs_init_authentication(struct ubifs_info *c) down_read(&keyring_key->sem); - ukp = user_key_payload_locked(keyring_key); - if (!ukp) { - /* key was revoked before we acquired its semaphore */ - err = -EKEYREVOKED; + key_material = key_extract_material(keyring_key, &len); + err = PTR_ERR_OR_ZERO(key_material); + if (err < 0) goto out; - } c->hash_tfm = crypto_alloc_shash(c->auth_hash_name, 0, 0); if (IS_ERR(c->hash_tfm)) { @@ -324,7 +329,7 @@ int ubifs_init_authentication(struct ubifs_info *c) goto out_free_hmac; } - err = crypto_shash_setkey(c->hmac_tfm, ukp->data, ukp->datalen); + err = crypto_shash_setkey(c->hmac_tfm, key_material, len); if (err) goto out_free_hmac;