From patchwork Thu Jan 3 14:32:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chun-Yi Lee X-Patchwork-Id: 10747453 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F200991E for ; Thu, 3 Jan 2019 14:33:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E25B7212E8 for ; Thu, 3 Jan 2019 14:33:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D61D8285DB; Thu, 3 Jan 2019 14:33:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 05787212E8 for ; Thu, 3 Jan 2019 14:33:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729649AbfACOdZ (ORCPT ); Thu, 3 Jan 2019 09:33:25 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:35735 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727436AbfACOdZ (ORCPT ); Thu, 3 Jan 2019 09:33:25 -0500 Received: by mail-pg1-f194.google.com with SMTP id s198so16087661pgs.2; Thu, 03 Jan 2019 06:33:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=akAh1HQffuLJ3sc/ovPWRTcFl4jaDX0Beb5XW/vb6Kw=; b=POoRBGjdD/evWXS3xe43k96zmlu/46ZiCrHiUlfF6DptnJYa9G0M23PiblbZ8WszIk dAVK4fGu0/EsE9mjC7vEbQ7s7VZn64HbvXOTtCJXJrcVQXaYPw/QZ6PEzsPZJuE2Zf11 DNypDNyPpUiFXgyYqsEbYsUbKrXlp42rbEVt2Q2MzUU0PSa2qyPVlVV6XpWz0nu0NsPU uF71pWN7olxpuqEC3itz4ChmtaxsQj78LbrzBfoPBJ0WAFgVPvDe41jLZZStEEvr07Ws JF4HhUogZsad98fO57CEG51QrrAIGNGccBt066hHTm8wdkghZPll8YmOMKdZUVpY6vVn 61lg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=akAh1HQffuLJ3sc/ovPWRTcFl4jaDX0Beb5XW/vb6Kw=; b=XikgV9q6ly8qzYUSaDs7XH7IRd5aLdsdNbQATn1jpUdpynqESqnZnl/pV7UKvLl2/W nzaNOtIaNxlkrSWBEyaMllQUJXN55oGeb5Gj0IKDNLE/yow3MFcmi2X1WlLU4wHqREzH q71k5Yih9/34hAw4bg28yrWAJPobbYN7HRvohYb4Xm3olaq+BnQtjs2FFikFDol34EPn La+mhGkV9M8VDiAie4oXZRbS2x6TYIjGeZCjhDKA1v+IGC+eK9Tci0/7l4Ymj/nPmuWz NgyR0AAFOfT8V9HaQXmVL4YzLM+ZmRhGiWYRdaB314Ws4EH1iFNYsunusnZ/lX2F4UWp UjBw== X-Gm-Message-State: AJcUukfNaKCcHWabX6OGymkecS9YhMVCh07YKfZ/6OKFkfj/YzTsG6LJ KaynlZViu3LEarUhmUnBTVM= X-Google-Smtp-Source: ALg8bN48PozTjMsgdPqPr7ml5mwCn9CPqJ8TC64v2EMd5P1SYcEzsXHevbsl6UqfCKS0RuB3Y/Qk1A== X-Received: by 2002:a63:f047:: with SMTP id s7mr17196057pgj.441.1546526004274; Thu, 03 Jan 2019 06:33:24 -0800 (PST) Received: from linux-l9pv.suse ([124.11.22.254]) by smtp.gmail.com with ESMTPSA id x3sm184403100pgt.45.2019.01.03.06.33.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 03 Jan 2019 06:33:23 -0800 (PST) From: "Lee, Chun-Yi" X-Google-Original-From: "Lee, Chun-Yi" To: "Rafael J . Wysocki" , Pavel Machek Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, keyrings@vger.kernel.org, "Lee, Chun-Yi" , "Rafael J. Wysocki" , Chen Yu , Oliver Neukum , Ryan Chen , David Howells , Giovanni Gherdovich , Randy Dunlap , Jann Horn , Andy Lutomirski Subject: [PATCH 3/5] PM / hibernate: Encrypt snapshot image Date: Thu, 3 Jan 2019 22:32:25 +0800 Message-Id: <20190103143227.9138-4-jlee@suse.com> X-Mailer: git-send-email 2.12.3 In-Reply-To: <20190103143227.9138-1-jlee@suse.com> References: <20190103143227.9138-1-jlee@suse.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP To protect the secret in memory snapshot image, this patch adds the logic to encrypt snapshot pages by AES-CTR. Using AES-CTR is because it's simple, fast and parallelizable. But this patch didn't implement parallel encryption. The encrypt key is derived from the snapshot key. And the initialization vector will be kept in snapshot header for resuming. Cc: "Rafael J. Wysocki" Cc: Pavel Machek Cc: Chen Yu Cc: Oliver Neukum Cc: Ryan Chen Cc: David Howells Cc: Giovanni Gherdovich Cc: Randy Dunlap Cc: Jann Horn Cc: Andy Lutomirski Signed-off-by: "Lee, Chun-Yi" --- kernel/power/hibernate.c | 8 ++- kernel/power/power.h | 6 ++ kernel/power/snapshot.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 164 insertions(+), 4 deletions(-) diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 0dda6a9f0af1..5ac2ab6f4a0e 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -275,10 +275,14 @@ static int create_image(int platform_mode) if (error) return error; + error = snapshot_prepare_crypto(false, true); + if (error) + goto finish_hash; + error = dpm_suspend_end(PMSG_FREEZE); if (error) { pr_err("Some devices failed to power down, aborting hibernation\n"); - goto finish_hash; + goto finish_crypto; } error = platform_pre_snapshot(platform_mode); @@ -335,6 +339,8 @@ static int create_image(int platform_mode) dpm_resume_start(in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); + finish_crypto: + snapshot_finish_crypto(); finish_hash: snapshot_finish_hash(); diff --git a/kernel/power/power.h b/kernel/power/power.h index c614b0a294e3..41263fdd3a54 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -5,6 +5,7 @@ #include #include #include +#include /* The max size of encrypted key blob */ #define KEY_BLOB_BUFF_LEN 512 @@ -24,6 +25,7 @@ struct swsusp_info { unsigned long pages; unsigned long size; unsigned long trampoline_pfn; + u8 iv[AES_BLOCK_SIZE]; u8 signature[SNAPSHOT_DIGEST_SIZE]; } __aligned(PAGE_SIZE); @@ -44,6 +46,8 @@ extern void __init hibernate_image_size_init(void); #ifdef CONFIG_HIBERNATION_ENC_AUTH /* kernel/power/snapshot.c */ extern int snapshot_image_verify_decrypt(void); +extern int snapshot_prepare_crypto(bool may_sleep, bool create_iv); +extern void snapshot_finish_crypto(void); extern int snapshot_prepare_hash(bool may_sleep); extern void snapshot_finish_hash(void); /* kernel/power/snapshot_key.c */ @@ -53,6 +57,8 @@ extern int snapshot_get_auth_key(u8 *auth_key, bool may_sleep); extern int snapshot_get_enc_key(u8 *enc_key, bool may_sleep); #else static inline int snapshot_image_verify_decrypt(void) { return 0; } +static inline int snapshot_prepare_crypto(bool may_sleep, bool create_iv) { return 0; } +static inline void snapshot_finish_crypto(void) {} static inline int snapshot_prepare_hash(bool may_sleep) { return 0; } static inline void snapshot_finish_hash(void) {} static inline int snapshot_key_init(void) { return 0; } diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index e817c035f378..cd10ab5e4850 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -41,7 +41,11 @@ #include #include #ifdef CONFIG_HIBERNATION_ENC_AUTH +#include +#include +#include #include +#include #endif #include "power.h" @@ -1413,6 +1417,127 @@ static unsigned int nr_copy_pages; static void **h_buf; #ifdef CONFIG_HIBERNATION_ENC_AUTH +static struct skcipher_request *sk_req; +static u8 iv[AES_BLOCK_SIZE]; +static void *c_buffer; + +static void init_iv(struct swsusp_info *info) +{ + memcpy(info->iv, iv, AES_BLOCK_SIZE); +} + +static void load_iv(struct swsusp_info *info) +{ + memcpy(iv, info->iv, AES_BLOCK_SIZE); +} + +int snapshot_prepare_crypto(bool may_sleep, bool create_iv) +{ + char enc_key[DERIVED_KEY_SIZE]; + struct crypto_skcipher *tfm; + int ret = 0; + + ret = snapshot_get_enc_key(enc_key, may_sleep); + if (ret) { + pr_warn_once("enc key is invalid\n"); + return -EINVAL; + } + + c_buffer = (void *)get_zeroed_page(GFP_KERNEL); + if (!c_buffer) { + pr_err("Allocate crypto buffer page failed\n"); + return -ENOMEM; + } + + tfm = crypto_alloc_skcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) { + ret = PTR_ERR(tfm); + pr_err("failed to allocate skcipher (%d)\n", ret); + goto alloc_fail; + } + + ret = crypto_skcipher_setkey(tfm, enc_key, AES_MAX_KEY_SIZE); + if (ret) { + pr_err("failed to setkey (%d)\n", ret); + goto set_fail; + } + + sk_req = skcipher_request_alloc(tfm, GFP_KERNEL); + if (!sk_req) { + pr_err("failed to allocate request\n"); + ret = -ENOMEM; + goto set_fail; + } + if (may_sleep) + skcipher_request_set_callback(sk_req, CRYPTO_TFM_REQ_MAY_SLEEP, + NULL, NULL); + if (create_iv) + get_random_bytes(iv, AES_BLOCK_SIZE); + + return 0; + +set_fail: + crypto_free_skcipher(tfm); +alloc_fail: + __free_page(c_buffer); + + return ret; +} + +void snapshot_finish_crypto(void) +{ + struct crypto_skcipher *tfm; + + if (!sk_req) + return; + + tfm = crypto_skcipher_reqtfm(sk_req); + skcipher_request_zero(sk_req); + skcipher_request_free(sk_req); + crypto_free_skcipher(tfm); + __free_page(c_buffer); + sk_req = NULL; +} + +static int encrypt_data_page(void *hash_buffer) +{ + struct scatterlist src[1], dst[1]; + u8 iv_tmp[AES_BLOCK_SIZE]; + int ret = 0; + + if (!sk_req) + return 0; + + memcpy(iv_tmp, iv, sizeof(iv)); + sg_init_one(src, hash_buffer, PAGE_SIZE); + sg_init_one(dst, c_buffer, PAGE_SIZE); + skcipher_request_set_crypt(sk_req, src, dst, PAGE_SIZE, iv_tmp); + ret = crypto_skcipher_encrypt(sk_req); + + copy_page(hash_buffer, c_buffer); + memset(c_buffer, 0, PAGE_SIZE); + + return ret; +} + +static int decrypt_data_page(void *encrypted_page) +{ + struct scatterlist src[1], dst[1]; + u8 iv_tmp[AES_BLOCK_SIZE]; + int ret = 0; + + memcpy(iv_tmp, iv, sizeof(iv)); + sg_init_one(src, encrypted_page, PAGE_SIZE); + sg_init_one(dst, c_buffer, PAGE_SIZE); + skcipher_request_set_crypt(sk_req, src, dst, PAGE_SIZE, iv_tmp); + ret = crypto_skcipher_decrypt(sk_req); + + copy_page(encrypted_page, c_buffer); + memset(c_buffer, 0, PAGE_SIZE); + + return ret; +} + /* * Signature of snapshot image */ @@ -1508,22 +1633,30 @@ int snapshot_image_verify_decrypt(void) if (ret || !s4_verify_desc) goto error_prep; + ret = snapshot_prepare_crypto(true, false); + if (ret) + goto error_prep; + for (i = 0; i < nr_copy_pages; i++) { ret = crypto_shash_update(s4_verify_desc, *(h_buf + i), PAGE_SIZE); if (ret) - goto error_shash; + goto error_shash_crypto; + ret = decrypt_data_page(*(h_buf + i)); + if (ret) + goto error_shash_crypto; } ret = crypto_shash_final(s4_verify_desc, s4_verify_digest); if (ret) - goto error_shash; + goto error_shash_crypto; pr_debug("Signature %*phN\n", SNAPSHOT_DIGEST_SIZE, signature); pr_debug("Digest %*phN\n", SNAPSHOT_DIGEST_SIZE, s4_verify_digest); if (memcmp(signature, s4_verify_digest, SNAPSHOT_DIGEST_SIZE)) ret = -EKEYREJECTED; - error_shash: + error_shash_crypto: + snapshot_finish_crypto(); snapshot_finish_hash(); error_prep: @@ -1564,6 +1697,17 @@ __copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) crypto_buffer = page_address(d_page); } + /* Encrypt hashed page */ + encrypt_data_page(crypto_buffer); + + /* Copy encrypted buffer to destination page in high memory */ + if (PageHighMem(d_page)) { + void *kaddr = kmap_atomic(d_page); + + copy_page(kaddr, crypto_buffer); + kunmap_atomic(kaddr); + } + /* Generate digest */ if (!s4_verify_desc) continue; @@ -1638,6 +1782,8 @@ __copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) } static inline void alloc_h_buf(void) {} +static inline void init_iv(struct swsusp_info *info) {} +static inline void load_iv(struct swsusp_info *info) {} static inline void init_signature(struct swsusp_info *info) {} static inline void load_signature(struct swsusp_info *info) {} static inline void init_sig_verify(struct trampoline *t) {} @@ -2286,6 +2432,7 @@ static int init_header(struct swsusp_info *info) info->size = info->pages; info->size <<= PAGE_SHIFT; info->trampoline_pfn = page_to_pfn(virt_to_page(trampoline_virt)); + init_iv(info); init_signature(info); return init_header_complete(info); } @@ -2524,6 +2671,7 @@ static int load_header(struct swsusp_info *info) nr_copy_pages = info->image_pages; nr_meta_pages = info->pages - info->image_pages - 1; trampoline_pfn = info->trampoline_pfn; + load_iv(info); load_signature(info); } return error;