From patchwork Tue Aug 10 12:42:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 12428839 X-Patchwork-Delegate: herbert@gondor.apana.org.au 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 947CEC4338F for ; Tue, 10 Aug 2021 12:43:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78589604DC for ; Tue, 10 Aug 2021 12:43:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240723AbhHJMnX (ORCPT ); Tue, 10 Aug 2021 08:43:23 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:43704 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240733AbhHJMnQ (ORCPT ); Tue, 10 Aug 2021 08:43:16 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 356B1200B2; Tue, 10 Aug 2021 12:42:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1628599372; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jxVPhhmIEkG2QvaM+OJw+sU5fagj/1FaG8k8qmB+yhk=; b=PKDrajiHNK7ptsfVcnHMnWfbAmM/OdNxCsZ9Oghz60kXy42PLLdJXV5MFDzqeFQFvHcUxP fAorrLUXFfT0QPcpdHdinxQ3DcFBaoiEwlV6Fkaru/FF0ArePHCtvuygZO2z/RQ7eMZzjq GmaoIC5wllJEW7C/NVg0Xt192z0fevM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1628599372; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jxVPhhmIEkG2QvaM+OJw+sU5fagj/1FaG8k8qmB+yhk=; b=KWDew8DXXBDu1RO3QrVpLiy1DpqrQbOPWnFA4a4Yy+GAyhnKuqTzygXxGlKjXz3tuqsLIx LUDChVLgdtBIDhCQ== Received: from adalid.arch.suse.de (adalid.arch.suse.de [10.161.8.13]) by relay2.suse.de (Postfix) with ESMTP id 2045DA3B94; Tue, 10 Aug 2021 12:42:52 +0000 (UTC) Received: by adalid.arch.suse.de (Postfix, from userid 16045) id 885D2518C556; Tue, 10 Aug 2021 14:42:50 +0200 (CEST) From: Hannes Reinecke To: Christoph Hellwig Cc: Sagi Grimberg , Keith Busch , Herbert Xu , "David S . Miller" , linux-nvme@lists.infradead.org, linux-crypto@vger.kernel.org, Hannes Reinecke Subject: [PATCH 11/13] nvmet-auth: Diffie-Hellman key exchange support Date: Tue, 10 Aug 2021 14:42:28 +0200 Message-Id: <20210810124230.12161-12-hare@suse.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210810124230.12161-1-hare@suse.de> References: <20210810124230.12161-1-hare@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Implement Diffie-Hellman key exchange using FFDHE groups for NVMe In-Band Authentication. This patch adds a new host configfs attribute 'dhchap_dhgroup' to select the FFDHE group to use. Signed-off-by: Hannes Reinecke --- drivers/nvme/target/auth.c | 148 ++++++++++++++++++++++++- drivers/nvme/target/configfs.c | 31 ++++++ drivers/nvme/target/fabrics-cmd-auth.c | 30 ++++- drivers/nvme/target/nvmet.h | 6 + 4 files changed, 208 insertions(+), 7 deletions(-) diff --git a/drivers/nvme/target/auth.c b/drivers/nvme/target/auth.c index 5b5f3cd4f914..fe44593a37f8 100644 --- a/drivers/nvme/target/auth.c +++ b/drivers/nvme/target/auth.c @@ -53,6 +53,71 @@ int nvmet_auth_set_host_key(struct nvmet_host *host, const char *secret) return 0; } +int nvmet_setup_dhgroup(struct nvmet_ctrl *ctrl, int dhgroup_id) +{ + struct nvmet_host_link *p; + struct nvmet_host *host = NULL; + const char *dhgroup_kpp; + int ret = -ENOTSUPP; + + if (dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_NULL) + return 0; + + down_read(&nvmet_config_sem); + if (ctrl->subsys->type == NVME_NQN_DISC) + goto out_unlock; + + list_for_each_entry(p, &ctrl->subsys->hosts, entry) { + if (strcmp(nvmet_host_name(p->host), ctrl->hostnqn)) + continue; + host = p->host; + break; + } + if (!host) { + pr_debug("host %s not found\n", ctrl->hostnqn); + ret = -ENXIO; + goto out_unlock; + } + + if (host->dhchap_dhgroup_id != dhgroup_id) { + ret = -EINVAL; + goto out_unlock; + } + if (ctrl->dh_tfm) { + if (ctrl->dh_gid == dhgroup_id) { + pr_debug("reuse existing DH group %d\n", dhgroup_id); + ret = 0; + } else { + pr_debug("DH group mismatch (selected %d, requested %d)\n", + ctrl->dh_gid, dhgroup_id); + ret = -EINVAL; + } + goto out_unlock; + } + + dhgroup_kpp = nvme_auth_dhgroup_kpp(dhgroup_id); + if (!dhgroup_kpp) { + ret = -EINVAL; + goto out_unlock; + } + ctrl->dh_tfm = crypto_alloc_kpp(dhgroup_kpp, 0, 0); + if (IS_ERR(ctrl->dh_tfm)) { + pr_debug("failed to setup DH group %d, err %ld\n", + dhgroup_id, PTR_ERR(ctrl->dh_tfm)); + ret = PTR_ERR(ctrl->dh_tfm); + ctrl->dh_tfm = NULL; + } else { + ctrl->dh_gid = dhgroup_id; + ctrl->dh_keysize = nvme_auth_dhgroup_pubkey_size(dhgroup_id); + ret = 0; + } + +out_unlock: + up_read(&nvmet_config_sem); + + return ret; +} + int nvmet_setup_auth(struct nvmet_ctrl *ctrl) { int ret = 0; @@ -147,6 +212,11 @@ void nvmet_destroy_auth(struct nvmet_ctrl *ctrl) ctrl->shash_tfm = NULL; ctrl->shash_id = 0; } + if (ctrl->dh_tfm) { + crypto_free_kpp(ctrl->dh_tfm); + ctrl->dh_tfm = NULL; + ctrl->dh_gid = 0; + } if (ctrl->dhchap_key) { kfree(ctrl->dhchap_key); ctrl->dhchap_key = NULL; @@ -182,8 +252,18 @@ int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response, return ret; } if (ctrl->dh_gid != NVME_AUTH_DHCHAP_DHGROUP_NULL) { - ret = -ENOTSUPP; - goto out; + challenge = kmalloc(shash_len, GFP_KERNEL); + if (!challenge) { + ret = -ENOMEM; + goto out; + } + ret = nvme_auth_augmented_challenge(ctrl->shash_id, + req->sq->dhchap_skey, + req->sq->dhchap_skey_len, + req->sq->dhchap_c1, + challenge, shash_len); + if (ret) + goto out; } shash->tfm = ctrl->shash_tfm; @@ -256,8 +336,18 @@ int nvmet_auth_ctrl_hash(struct nvmet_req *req, u8 *response, return ret; } if (ctrl->dh_gid != NVME_AUTH_DHCHAP_DHGROUP_NULL) { - ret = -ENOTSUPP; - goto out; + challenge = kmalloc(shash_len, GFP_KERNEL); + if (!challenge) { + ret = -ENOMEM; + goto out; + } + ret = nvme_auth_augmented_challenge(ctrl->shash_id, + req->sq->dhchap_skey, + req->sq->dhchap_skey_len, + req->sq->dhchap_c2, + challenge, shash_len); + if (ret) + goto out; } shash->tfm = ctrl->shash_tfm; @@ -299,3 +389,53 @@ int nvmet_auth_ctrl_hash(struct nvmet_req *req, u8 *response, kfree_sensitive(ctrl_response); return 0; } + +int nvmet_auth_ctrl_exponential(struct nvmet_req *req, + u8 *buf, int buf_size) +{ + struct nvmet_ctrl *ctrl = req->sq->ctrl; + int ret; + + if (!ctrl->dh_tfm) { + pr_warn("No DH algorithm!\n"); + return -ENOKEY; + } + ret = nvme_auth_gen_pubkey(ctrl->dh_tfm, buf, buf_size); + if (ret == -EOVERFLOW) { + pr_debug("public key buffer too small, need %d is %d\n", + crypto_kpp_maxsize(ctrl->dh_tfm), buf_size); + ret = -ENOKEY; + } else if (ret) { + pr_debug("failed to generate public key, err %d\n", ret); + ret = -ENOKEY; + } else + pr_debug("%s: ctrl public key %*ph\n", __func__, + (int)buf_size, buf); + + return ret; +} + +int nvmet_auth_ctrl_sesskey(struct nvmet_req *req, + u8 *pkey, int pkey_size) +{ + struct nvmet_ctrl *ctrl = req->sq->ctrl; + int ret; + + req->sq->dhchap_skey_len = + nvme_auth_dhgroup_privkey_size(ctrl->dh_gid); + req->sq->dhchap_skey = kzalloc(req->sq->dhchap_skey_len, GFP_KERNEL); + if (!req->sq->dhchap_skey) + return -ENOMEM; + ret = nvme_auth_gen_shared_secret(ctrl->dh_tfm, + pkey, pkey_size, + req->sq->dhchap_skey, + req->sq->dhchap_skey_len); + if (ret) + pr_debug("failed to compute shared secred, err %d\n", ret); + else + pr_debug("%s: shared secret %*ph\n", __func__, + (int)req->sq->dhchap_skey_len, + req->sq->dhchap_skey); + + return ret; +} diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c index e0760911a761..e9b8884a83b0 100644 --- a/drivers/nvme/target/configfs.c +++ b/drivers/nvme/target/configfs.c @@ -1712,9 +1712,40 @@ static ssize_t nvmet_host_dhchap_hash_store(struct config_item *item, CONFIGFS_ATTR(nvmet_host_, dhchap_hash); +static ssize_t nvmet_host_dhchap_dhgroup_show(struct config_item *item, + char *page) +{ + struct nvmet_host *host = to_host(item); + const char *dhgroup = nvme_auth_dhgroup_name(host->dhchap_dhgroup_id); + + return sprintf(page, "%s\n", dhgroup ? dhgroup : "none"); +} + +static ssize_t nvmet_host_dhchap_dhgroup_store(struct config_item *item, + const char *page, size_t count) +{ + struct nvmet_host *host = to_host(item); + int dhgroup_id; + + dhgroup_id = nvme_auth_dhgroup_id(page); + if (dhgroup_id < 0) + return -EINVAL; + if (dhgroup_id != NVME_AUTH_DHCHAP_DHGROUP_NULL) { + const char *kpp = nvme_auth_dhgroup_kpp(dhgroup_id); + + if (!crypto_has_kpp(kpp, 0, 0)) + return -EINVAL; + } + host->dhchap_dhgroup_id = dhgroup_id; + return count; +} + +CONFIGFS_ATTR(nvmet_host_, dhchap_dhgroup); + static struct configfs_attribute *nvmet_host_attrs[] = { &nvmet_host_attr_dhchap_key, &nvmet_host_attr_dhchap_hash, + &nvmet_host_attr_dhchap_dhgroup, NULL, }; #endif /* CONFIG_NVME_TARGET_AUTH */ diff --git a/drivers/nvme/target/fabrics-cmd-auth.c b/drivers/nvme/target/fabrics-cmd-auth.c index ab9dfc06bac0..2f1b95098917 100644 --- a/drivers/nvme/target/fabrics-cmd-auth.c +++ b/drivers/nvme/target/fabrics-cmd-auth.c @@ -64,13 +64,24 @@ static u16 nvmet_auth_negotiate(struct nvmet_req *req, void *d) null_dh = dhgid; continue; } + if (ctrl->dh_tfm && ctrl->dh_gid == dhgid) { + pr_debug("%s: ctrl %d qid %d: reusing existing DH group %d\n", + __func__, ctrl->cntlid, req->sq->qid, dhgid); + break; + } + if (nvmet_setup_dhgroup(ctrl, dhgid) < 0) + continue; + if (nvme_auth_gen_privkey(ctrl->dh_tfm, dhgid) == 0) + break; + crypto_free_kpp(ctrl->dh_tfm); + ctrl->dh_tfm = NULL; + ctrl->dh_gid = 0; } - if (null_dh < 0) { + if (!ctrl->dh_tfm && null_dh < 0) { pr_debug("%s: ctrl %d qid %d: no DH group selected\n", __func__, ctrl->cntlid, req->sq->qid); return NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE; } - ctrl->dh_gid = null_dh; pr_debug("%s: ctrl %d qid %d: DH group %s (%d)\n", __func__, ctrl->cntlid, req->sq->qid, nvme_auth_dhgroup_name(ctrl->dh_gid), ctrl->dh_gid); @@ -91,7 +102,11 @@ static u16 nvmet_auth_reply(struct nvmet_req *req, void *d) return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD; if (data->dhvlen) { - return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD; + if (!ctrl->dh_tfm) + return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD; + if (nvmet_auth_ctrl_sesskey(req, data->rval + 2 * data->hl, + data->dhvlen) < 0) + return NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE; } response = kmalloc(data->hl, GFP_KERNEL); @@ -232,6 +247,7 @@ void nvmet_execute_auth_send(struct nvmet_req *req) NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD; goto done_kfree; } + switch (data->auth_id) { case NVME_AUTH_DHCHAP_MESSAGE_REPLY: status = nvmet_auth_reply(req, d); @@ -303,6 +319,8 @@ static int nvmet_auth_challenge(struct nvmet_req *req, void *d, int al) int hash_len = crypto_shash_digestsize(ctrl->shash_tfm); int data_size = sizeof(*d) + hash_len; + if (ctrl->dh_tfm) + data_size += ctrl->dh_keysize; if (al < data_size) { pr_debug("%s: buffer too small (al %d need %d)\n", __func__, al, data_size); @@ -321,6 +339,12 @@ static int nvmet_auth_challenge(struct nvmet_req *req, void *d, int al) return -ENOMEM; get_random_bytes(req->sq->dhchap_c1, data->hl); memcpy(data->cval, req->sq->dhchap_c1, data->hl); + if (ctrl->dh_tfm) { + data->dhgid = ctrl->dh_gid; + data->dhvlen = ctrl->dh_keysize; + ret = nvmet_auth_ctrl_exponential(req, data->cval + data->hl, + data->dhvlen); + } pr_debug("%s: ctrl %d qid %d seq %d transaction %d hl %d dhvlen %d\n", __func__, ctrl->cntlid, req->sq->qid, req->sq->dhchap_s1, req->sq->dhchap_tid, data->hl, data->dhvlen); diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h index adcbe2523710..e9d18ca6ebbf 100644 --- a/drivers/nvme/target/nvmet.h +++ b/drivers/nvme/target/nvmet.h @@ -227,6 +227,7 @@ struct nvmet_ctrl { size_t dhchap_key_len; struct crypto_shash *shash_tfm; u8 shash_id; + struct crypto_kpp *dh_tfm; u32 dh_gid; u32 dh_keysize; #endif @@ -693,6 +694,7 @@ int nvmet_setup_auth(struct nvmet_ctrl *ctrl); void nvmet_init_auth(struct nvmet_ctrl *ctrl, struct nvmet_req *req); void nvmet_destroy_auth(struct nvmet_ctrl *ctrl); void nvmet_auth_sq_free(struct nvmet_sq *sq); +int nvmet_setup_dhgroup(struct nvmet_ctrl *ctrl, int dhgroup_id); bool nvmet_check_auth_status(struct nvmet_req *req); int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response, unsigned int hash_len); @@ -702,6 +704,10 @@ static inline bool nvmet_has_auth(struct nvmet_ctrl *ctrl) { return ctrl->shash_tfm != NULL; } +int nvmet_auth_ctrl_exponential(struct nvmet_req *req, + u8 *buf, int buf_size); +int nvmet_auth_ctrl_sesskey(struct nvmet_req *req, + u8 *buf, int buf_size); #else static inline int nvmet_setup_auth(struct nvmet_ctrl *ctrl) {