From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 EF73EC04A6B for ; Wed, 8 May 2019 14:46:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9705216F4 for ; Wed, 8 May 2019 14:46:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728016AbfEHOq3 (ORCPT ); Wed, 8 May 2019 10:46:29 -0400 Received: from mga03.intel.com ([134.134.136.65]:59551 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728176AbfEHOo4 (ORCPT ); Wed, 8 May 2019 10:44:56 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 May 2019 07:44:53 -0700 X-ExtLoop1: 1 Received: from black.fi.intel.com ([10.237.72.28]) by FMSMGA003.fm.intel.com with ESMTP; 08 May 2019 07:44:49 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id AF33E11CE; Wed, 8 May 2019 17:44:31 +0300 (EEST) From: "Kirill A. Shutemov" To: Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , Peter Zijlstra , Andy Lutomirski , David Howells Cc: Kees Cook , Dave Hansen , Kai Huang , Jacob Pan , Alison Schofield , linux-mm@kvack.org, kvm@vger.kernel.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A . Shutemov" Subject: [PATCH, RFC 60/62] x86/mktme: Document the MKTME Key Service API Date: Wed, 8 May 2019 17:44:20 +0300 Message-Id: <20190508144422.13171-61-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190508144422.13171-1-kirill.shutemov@linux.intel.com> References: <20190508144422.13171-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alison Schofield Signed-off-by: Alison Schofield Signed-off-by: Kirill A. Shutemov --- Documentation/x86/mktme/index.rst | 1 + Documentation/x86/mktme/mktme_keys.rst | 96 ++++++++++++++++++++++++++ 2 files changed, 97 insertions(+) create mode 100644 Documentation/x86/mktme/mktme_keys.rst diff --git a/Documentation/x86/mktme/index.rst b/Documentation/x86/mktme/index.rst index 0f021cc4a2db..8cf2b7d62091 100644 --- a/Documentation/x86/mktme/index.rst +++ b/Documentation/x86/mktme/index.rst @@ -8,3 +8,4 @@ Multi-Key Total Memory Encryption (MKTME) mktme_overview mktme_mitigations mktme_configuration + mktme_keys diff --git a/Documentation/x86/mktme/mktme_keys.rst b/Documentation/x86/mktme/mktme_keys.rst new file mode 100644 index 000000000000..161871dee0dc --- /dev/null +++ b/Documentation/x86/mktme/mktme_keys.rst @@ -0,0 +1,96 @@ +MKTME Key Service API +===================== +MKTME is a new key service type added to the Linux Kernel Key Service. + +The MKTME Key Service type is available when CONFIG_X86_INTEL_MKTME is +turned on in Intel platforms that support the MKTME feature. + +The MKTME Key Service type manages the allocation of hardware encryption +keys. Users can request an MKTME type key and then use that key to +encrypt memory with the encrypt_mprotect() system call. + +Usage +----- + When using the Kernel Key Service to request an *mktme* key, + specify the *payload* as follows: + + type= + *user* User will supply the encryption key data. Use this + type to directly program a hardware encryption key. + + *cpu* User requests a CPU generated encryption key. + The CPU generates and assigns an ephemeral key. + + *no-encrypt* + User requests that hardware does not encrypt + memory when this key is in use. + + algorithm= + When type=user or type=cpu the algorithm field must be + *aes-xts-128* + + When type=clear or type=no-encrypt the algorithm field + must not be present in the payload. + + key= + When type=user the user must supply a 128 bit encryption + key as exactly 32 ASCII hexadecimal characters. + + When type=cpu the user may optionally supply 128 bits of + entropy for the CPU generated encryption key in this field. + It must be exactly 32 ASCII hexadecimal characters. + + When type=no-encrypt this key field must not be present + in the payload. + + tweak= + When type=user the user must supply a 128 bit tweak key + as exactly 32 ASCII hexadecimal characters. + + When type=cpu the user may optionally supply 128 bits of + entropy for the CPU generated tweak key in this field. + It must be exactly 32 ASCII hexadecimal characters. + + When type=no-encrypt the tweak field must not be present + in the payload. + +ERRORS +------ + In addition to the Errors returned from the Kernel Key Service, + add_key(2) or keyctl(1) commands, the MKTME Key Service type may + return the following errors: + + EINVAL for any payload specification that does not match the + MKTME type payload as defined above. + + EACCES for access denied. The MKTME key type uses capabilities + to restrict the allocation of keys to privileged users. + CAP_SYS_RESOURCE is required, but it will accept the + broader capability of CAP_SYS_ADMIN. See capabilities(7). + + ENOKEY if a hardware key cannot be allocated. Additional error + messages will describe the hardware programming errors. + +EXAMPLES +-------- + Add a 'user' type key:: + + char \*options_USER = "type=user + algorithm=aes-xts-128 + key=12345678912345671234567891234567 + tweak=12345678912345671234567891234567"; + + key = add_key("mktme", "name", options_USER, strlen(options_USER), + KEY_SPEC_THREAD_KEYRING); + + Add a 'cpu' type key:: + + char \*options_USER = "type=cpu algorithm=aes-xts-128"; + + key = add_key("mktme", "name", options_CPU, strlen(options_CPU), + KEY_SPEC_THREAD_KEYRING); + + Add a "no-encrypt' type key:: + + key = add_key("mktme", "name", "no-encrypt", strlen(options_CPU), + KEY_SPEC_THREAD_KEYRING); -- 2.20.1