From patchwork Tue Sep 1 16:51:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Snowberg X-Patchwork-Id: 11749269 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C2554618 for ; Tue, 1 Sep 2020 16:52:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F4292078B for ; Tue, 1 Sep 2020 16:52:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="cFY7bYQx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730163AbgIAQwb (ORCPT ); Tue, 1 Sep 2020 12:52:31 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:46642 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730101AbgIAQw2 (ORCPT ); Tue, 1 Sep 2020 12:52:28 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 081GnlJc130927; Tue, 1 Sep 2020 16:51:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id; s=corp-2020-01-29; bh=7ImOCtuv9amf35LQt91qM2sCyLRaBVRabZfd2OBAOA4=; b=cFY7bYQx1B1U6JCthfC3F3KeaWeR9qh4FypjRJG3sRqBOCs2QQEy/YPT/FtzRuF9/u88 ApQYQUsxfCjYNDyKvARmTOgqm5cIFwcOXwgeVllVVGDrVKiYEHntRY1RVjPtGgNr63FR T+P+fKozETQT4o7gDDSxU39GHzDxy+sYKsTuV+1TPCOgfESJ4VPGYkxzSCe/4u8HaMxQ 5LoHnLx/OjqAo5+dfb8nzhPxDNaMqvXoCu487EaxlGmcJhJ4jaWYxJb3yGnxrU02q2v7 K4o9TWGItMsI6PkINV/Ldp+P0D2+5C9vCF39rLVnPSVEnf3TLIuRswtq8StjUuDd/7Np Qw== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 339dmmv467-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 01 Sep 2020 16:51:58 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 081Gngnv186705; Tue, 1 Sep 2020 16:51:57 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 3380xwsk3h-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 01 Sep 2020 16:51:57 +0000 Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 081GprF5017755; Tue, 1 Sep 2020 16:51:55 GMT Received: from localhost.us.oracle.com (/10.147.27.2) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 01 Sep 2020 09:51:52 -0700 From: Eric Snowberg To: dhowells@redhat.com, dwmw2@infradead.org Cc: jarkko.sakkinen@linux.intel.com, jmorris@namei.org, serge@hallyn.com, zohar@linux.ibm.com, erichte@linux.ibm.com, nayna@linux.ibm.com, mpe@ellerman.id.au, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, eric.snowberg@oracle.com Subject: [RFC PATCH] certs: Add EFI_CERT_X509_GUID support for dbx entries Date: Tue, 1 Sep 2020 12:51:43 -0400 Message-Id: <20200901165143.10295-1-eric.snowberg@oracle.com> X-Mailer: git-send-email 2.18.1 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9731 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 adultscore=0 phishscore=0 malwarescore=0 bulkscore=0 mlxscore=0 mlxlogscore=999 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009010140 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9731 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 phishscore=0 mlxlogscore=999 adultscore=0 impostorscore=0 mlxscore=0 suspectscore=0 spamscore=0 clxscore=1011 malwarescore=0 lowpriorityscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009010140 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: The Secure Boot Forbidden Signature Database, dbx, contains a list of now revoked signatures and keys previously approved to boot with UEFI Secure Boot enabled. The dbx is capable of containing any number of EFI_CERT_X509_SHA256_GUID, EFI_CERT_SHA256_GUID, and EFI_CERT_X509_GUID entries. Currently when EFI_CERT_X509_GUID are contained in the dbx, the entries are skipped. This change adds support for EFI_CERT_X509_GUID dbx entries. When a EFI_CERT_X509_GUID is found, it is added as an asymmetrical key to the .blacklist keyring. Anytime the .platform keyring is used, the keys in the .blacklist keyring are referenced, if a matching key is found, the key will be rejected. Signed-off-by: Eric Snowberg --- certs/blacklist.c | 36 +++++++++++++++++++ certs/system_keyring.c | 6 ++++ include/keys/system_keyring.h | 11 ++++++ .../platform_certs/keyring_handler.c | 11 ++++++ 4 files changed, 64 insertions(+) diff --git a/certs/blacklist.c b/certs/blacklist.c index 6514f9ebc943..17ebf50cf0ae 100644 --- a/certs/blacklist.c +++ b/certs/blacklist.c @@ -15,6 +15,7 @@ #include #include #include +#include #include "blacklist.h" static struct key *blacklist_keyring; @@ -100,6 +101,41 @@ int mark_hash_blacklisted(const char *hash) return 0; } +int mark_key_revocationlisted(const char *data, size_t size) +{ + key_ref_t key; + + key = key_create_or_update(make_key_ref(blacklist_keyring, true), + "asymmetric", + NULL, + data, + size, + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW), + KEY_ALLOC_NOT_IN_QUOTA | + KEY_ALLOC_BUILT_IN); + + if (IS_ERR(key)) { + pr_err("Problem with revocation key (%ld)\n", PTR_ERR(key)); + return PTR_ERR(key); + } + + return 0; +} + +int is_key_revocationlisted(struct pkcs7_message *pkcs7) +{ + int ret; + + ret = pkcs7_validate_trust(pkcs7, blacklist_keyring); + + if (ret == 0) + return -EKEYREJECTED; + + return -ENOKEY; +} +EXPORT_SYMBOL_GPL(is_key_revocationlisted); + /** * is_hash_blacklisted - Determine if a hash is blacklisted * @hash: The hash to be checked as a binary blob diff --git a/certs/system_keyring.c b/certs/system_keyring.c index 798291177186..f8ea96219155 100644 --- a/certs/system_keyring.c +++ b/certs/system_keyring.c @@ -241,6 +241,12 @@ int verify_pkcs7_message_sig(const void *data, size_t len, pr_devel("PKCS#7 platform keyring is not available\n"); goto error; } + + ret = is_key_revocationlisted(pkcs7); + if (ret != -ENOKEY) { + pr_devel("PKCS#7 platform key revocationlisted\n"); + goto error; + } } ret = pkcs7_validate_trust(pkcs7, trusted_keys); if (ret < 0) { diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h index fb8b07daa9d1..b6991cfe1b6d 100644 --- a/include/keys/system_keyring.h +++ b/include/keys/system_keyring.h @@ -31,11 +31,14 @@ extern int restrict_link_by_builtin_and_secondary_trusted( #define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted #endif +extern struct pkcs7_message *pkcs7; #ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING extern int mark_hash_blacklisted(const char *hash); +extern int mark_key_revocationlisted(const char *data, size_t size); extern int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type); extern int is_binary_blacklisted(const u8 *hash, size_t hash_len); +extern int is_key_revocationlisted(struct pkcs7_message *pkcs7); #else static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type) @@ -47,6 +50,14 @@ static inline int is_binary_blacklisted(const u8 *hash, size_t hash_len) { return 0; } +static inline int mark_key_revocationlisted(const char *data, size_t size) +{ + return 0; +} +static inline int is_key_revocationlisted(struct pkcs7_message *pkcs7) +{ + return -ENOKEY; +} #endif #ifdef CONFIG_IMA_BLACKLIST_KEYRING diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c index c5ba695c10e3..cc5a43804bc4 100644 --- a/security/integrity/platform_certs/keyring_handler.c +++ b/security/integrity/platform_certs/keyring_handler.c @@ -55,6 +55,15 @@ static __init void uefi_blacklist_binary(const char *source, uefi_blacklist_hash(source, data, len, "bin:", 4); } +/* + * Revocationlist the X509 cert + */ +static __init void uefi_revocationlist_x509(const char *source, + const void *data, size_t len) +{ + mark_key_revocationlisted(data, len); +} + /* * Return the appropriate handler for particular signature list types found in * the UEFI db and MokListRT tables. @@ -76,5 +85,7 @@ __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type) return uefi_blacklist_x509_tbs; if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0) return uefi_blacklist_binary; + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) + return uefi_revocationlist_x509; return 0; }