From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932233AbaE1PKK (ORCPT ); Wed, 28 May 2014 11:10:10 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:46036 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753588AbaE1PKG (ORCPT ); Wed, 28 May 2014 11:10:06 -0400 From: Mimi Zohar To: linux-security-module Cc: Mimi Zohar , Dmitry Kasatkin , David Howells , Josh Boyer , keyrings , linux-kernel Subject: [RFC PATCH v4 3/4] ima: define '.ima' as a builtin 'trusted' keyring Date: Wed, 28 May 2014 11:09:43 -0400 Message-Id: <1401289784-31340-4-git-send-email-zohar@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1401289784-31340-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1401289784-31340-1-git-send-email-zohar@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14052815-1542-0000-0000-000002265D67 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Require all keys added to the IMA keyring be signed by an existing trusted key on the system trusted keyring. Changelog v1: - don't link IMA trusted keyring to user keyring Changelog: - define stub integrity_init_keyring() function (reported-by Fengguang Wu) - differentiate between regular and trusted keyring names. - replace printk with pr_info (D. Kasatkin) - only make the IMA keyring a trusted keyring (reported-by D. Kastatkin) - define stub integrity_init_keyring() definition based on CONFIG_INTEGRITY_SIGNATURE, not CONFIG_INTEGRITY_ASYMMETRIC_KEYS. (reported-by Jim Davis) Signed-off-by: Mimi Zohar --- security/integrity/digsig.c | 26 +++++++++++++++++++++++++- security/integrity/ima/Kconfig | 8 ++++++++ security/integrity/ima/ima_appraise.c | 11 +++++++++++ security/integrity/integrity.h | 5 +++++ 4 files changed, 49 insertions(+), 1 deletion(-) diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index b4af4eb..7da5f9c 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -13,7 +13,9 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include +#include #include #include @@ -24,7 +26,11 @@ static struct key *keyring[INTEGRITY_KEYRING_MAX]; static const char *keyring_name[INTEGRITY_KEYRING_MAX] = { "_evm", "_module", +#ifndef CONFIG_IMA_TRUSTED_KEYRING "_ima", +#else + ".ima", +#endif }; int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, @@ -35,7 +41,7 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, if (!keyring[id]) { keyring[id] = - request_key(&key_type_keyring, keyring_name[id], NULL); + request_key(&key_type_keyring, keyring_name[id], NULL); if (IS_ERR(keyring[id])) { int err = PTR_ERR(keyring[id]); pr_err("no %s keyring: %d\n", keyring_name[id], err); @@ -56,3 +62,21 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, return -EOPNOTSUPP; } + +int integrity_init_keyring(const unsigned int id) +{ + const struct cred *cred = current_cred(); + + keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0), + KGIDT_INIT(0), cred, + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ | + KEY_USR_WRITE | KEY_USR_SEARCH), + KEY_ALLOC_NOT_IN_QUOTA, NULL); + if (!IS_ERR(keyring[id])) + set_bit(KEY_FLAG_TRUSTED_ONLY, &keyring[id]->flags); + else + pr_info("Can't allocate %s keyring (%ld)\n", + keyring_name[id], PTR_ERR(keyring[id])); + return 0; +} diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 81a2797..dad8d4c 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -123,3 +123,11 @@ config IMA_APPRAISE For more information on integrity appraisal refer to: If unsure, say N. + +config IMA_TRUSTED_KEYRING + bool "Require all keys on the _ima keyring be signed" + depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING + default y + help + This option requires that all keys added to the _ima + keyring be signed by a key on the system trusted keyring. diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index d3113d4..003ff46 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -385,3 +385,14 @@ int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name) } return result; } + +#ifdef CONFIG_IMA_TRUSTED_KEYRING +static int __init init_ima_keyring(void) +{ + int ret; + + ret = integrity_init_keyring(INTEGRITY_KEYRING_IMA); + return 0; +} +late_initcall(init_ima_keyring); +#endif diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 33c0a70..09c440d 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -124,6 +124,7 @@ struct integrity_iint_cache *integrity_iint_find(struct inode *inode); int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, const char *digest, int digestlen); +int integrity_init_keyring(const unsigned int id); #else static inline int integrity_digsig_verify(const unsigned int id, @@ -133,6 +134,10 @@ static inline int integrity_digsig_verify(const unsigned int id, return -EOPNOTSUPP; } +static inline int integrity_init_keyring(const unsigned int id) +{ + return 0; +} #endif /* CONFIG_INTEGRITY_SIGNATURE */ #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS -- 1.8.1.4