[11/12] nvmet-auth: Diffie-Hellman key exchange support

Message ID	20211112125928.97318-12-hare@suse.de (mailing list archive)
State	Not Applicable
Delegated to:	Herbert Xu
Headers	show Return-Path: <linux-crypto-owner@kernel.org> From: Hannes Reinecke <hare@suse.de> To: Sagi Grimberg <sagi@grimberg.me> Cc: Christoph Hellwig <hch@lst.de>, Keith Busch <keith.busch@wdc.com>, linux-nvme@lists.infradead.org, Herbert Xu <herbert@gondor.apana.org.au>, David Miller <davem@davemloft.net>, linux-crypto@vger.kernel.org, Hannes Reinecke <hare@suse.de> Subject: [PATCH 11/12] nvmet-auth: Diffie-Hellman key exchange support Date: Fri, 12 Nov 2021 13:59:27 +0100 Message-Id: <20211112125928.97318-12-hare@suse.de> In-Reply-To: <20211112125928.97318-1-hare@suse.de> References: <20211112125928.97318-1-hare@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	nvme: In-band authentication support \| expand [PATCHv5,00/12] nvme: In-band authentication support [01/12] crypto: add crypto_has_shash() [02/12] crypto: add crypto_has_kpp() [03/12] crypto/ffdhe: Finite Field DH Ephemeral Parameters [04/12] lib/base64: RFC4648-compliant base64 encoding [05/12] nvme: add definitions for NVMe In-Band authentication [06/12] nvme-fabrics: decode 'authentication required' connect error [07/12] nvme: Implement In-Band authentication [08/12] nvme-auth: Diffie-Hellman key exchange support [09/12] nvmet: Parse fabrics commands on all queues [10/12] nvmet: Implement basic In-Band Authentication [11/12] nvmet-auth: Diffie-Hellman key exchange support [12/12] nvmet-auth: expire authentication sessions

diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig index 70f3c385fc9f..2e41d70fd881 100644 --- a/drivers/nvme/target/Kconfig +++ b/drivers/nvme/target/Kconfig @@ -90,6 +90,7 @@ config NVME_TARGET_AUTH select CRYPTO_HMAC select CRYPTO_SHA256 select CRYPTO_SHA512 + select CRYPTO_FFDHE help This enables support for NVMe over Fabrics In-band Authentication diff --git a/drivers/nvme/target/auth.c b/drivers/nvme/target/auth.c index e63d12a0f446..7486077ca33e 100644 --- a/drivers/nvme/target/auth.c +++ b/drivers/nvme/target/auth.c @@ -69,6 +69,71 @@ int nvmet_auth_set_ctrl_key(struct nvmet_host *host, const char *secret) return host->dhchap_ctrl_secret ? 0 : -ENOMEM; } +int nvmet_setup_dhgroup(struct nvmet_ctrl *ctrl, int dhgroup_id) +{ + const char *dhgroup_kpp; + int ret = 0; + + pr_debug("%s: ctrl %d selecting dhgroup %d\n", + __func__, ctrl->cntlid, dhgroup_id); + + if (ctrl->dh_tfm) { + if (ctrl->dh_gid == dhgroup_id) { + pr_debug("%s: ctrl %d reuse existing DH group %d\n", + __func__, ctrl->cntlid, dhgroup_id); + return 0; + } + crypto_free_kpp(ctrl->dh_tfm); + ctrl->dh_tfm = NULL; + ctrl->dh_gid = 0; + } + + if (dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_NULL) + return 0; + + dhgroup_kpp = nvme_auth_dhgroup_kpp(dhgroup_id); + if (!dhgroup_kpp) { + pr_debug("%s: ctrl %d invalid DH group %d\n", + __func__, ctrl->cntlid, dhgroup_id); + return -EINVAL; + } + ctrl->dh_tfm = crypto_alloc_kpp(dhgroup_kpp, 0, 0); + if (IS_ERR(ctrl->dh_tfm)) { + pr_debug("%s: ctrl %d failed to setup DH group %d, err %ld\n", + __func__, ctrl->cntlid, dhgroup_id, + PTR_ERR(ctrl->dh_tfm)); + ret = PTR_ERR(ctrl->dh_tfm); + ctrl->dh_tfm = NULL; + ctrl->dh_gid = 0; + } else { + ctrl->dh_gid = dhgroup_id; + ctrl->dh_keysize = nvme_auth_dhgroup_pubkey_size(dhgroup_id); + pr_debug("%s: ctrl %d setup DH group %d\n", + __func__, ctrl->cntlid, ctrl->dh_gid); + ret = nvme_auth_gen_privkey(ctrl->dh_tfm, ctrl->dh_gid); + if (ret < 0) + pr_debug("%s: ctrl %d failed to generate private key, err %d\n", + __func__, ctrl->cntlid, ret); + kfree_sensitive(ctrl->dh_key); + ctrl->dh_key = kzalloc(ctrl->dh_keysize, GFP_KERNEL); + if (!ctrl->dh_key) { + pr_warn("ctrl %d failed to allocate public key\n", + ctrl->cntlid); + return -ENOMEM; + } + ret = nvme_auth_gen_pubkey(ctrl->dh_tfm, ctrl->dh_key, + ctrl->dh_keysize); + if (ret < 0) { + pr_warn("ctrl %d failed to generate public key\n", + ctrl->cntlid); + kfree(ctrl->dh_key); + ctrl->dh_key = NULL; + } + } + + return ret; +} + int nvmet_setup_auth(struct nvmet_ctrl *ctrl) { int ret = 0; @@ -96,6 +161,10 @@ int nvmet_setup_auth(struct nvmet_ctrl *ctrl) goto out_unlock; } + ret = nvmet_setup_dhgroup(ctrl, host->dhchap_dhgroup_id); + if (ret < 0) + pr_warn("Failed to setup DH group"); + if (!host->dhchap_secret) { pr_debug("No authentication provided\n"); goto out_unlock; @@ -180,6 +249,13 @@ void nvmet_destroy_auth(struct nvmet_ctrl *ctrl) { ctrl->shash_id = 0; + if (ctrl->dh_tfm) { + crypto_free_kpp(ctrl->dh_tfm); + ctrl->dh_tfm = NULL; + ctrl->dh_gid = 0; + } + kfree_sensitive(ctrl->dh_key); + ctrl->dh_key = NULL; kfree_sensitive(ctrl->dhchap_key); ctrl->dhchap_key = NULL; kfree_sensitive(ctrl->dhchap_ctrl_key); @@ -239,8 +315,18 @@ int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response, goto out_free_response; 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_free_response; + } + 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_free_response; } pr_debug("ctrl %d qid %d host response seq %d transaction %d\n", @@ -343,8 +429,18 @@ int nvmet_auth_ctrl_hash(struct nvmet_req *req, u8 *response, goto out_free_response; 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_free_response; + } + 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_free_response; } shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(shash_tfm), @@ -397,3 +493,51 @@ int nvmet_auth_ctrl_hash(struct nvmet_req *req, u8 *response, crypto_free_shash(shash_tfm); 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 = 0; + + if (!ctrl->dh_key) { + pr_warn("ctrl %d no DH public key!\n", ctrl->cntlid); + return -ENOKEY; + } + if (buf_size != ctrl->dh_keysize) { + pr_debug("%s: ctrl %d public key buffer size mismatch, need %d is %d\n", + __func__, ctrl->cntlid, ctrl->dh_keysize, buf_size); + ret = -EINVAL; + } else { + memcpy(buf, ctrl->dh_key, buf_size); + pr_debug("%s: ctrl %d public key %*ph\n", __func__, + ctrl->cntlid, (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 38bafbc69714..1e272d0760ce 100644 --- a/drivers/nvme/target/configfs.c +++ b/drivers/nvme/target/configfs.c @@ -1784,10 +1784,41 @@ 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_ctrl_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 b5f46cdb97fe..51955fbc6c55 100644 --- a/drivers/nvme/target/fabrics-cmd-auth.c +++ b/drivers/nvme/target/fabrics-cmd-auth.c @@ -61,7 +61,7 @@ static u16 nvmet_auth_negotiate(struct nvmet_req *req, void *d) data->auth_protocol[0].dhchap.dhlen; i++) { int tmp_dhgid = data->auth_protocol[0].dhchap.idlist[i]; - if (tmp_dhgid == NVME_AUTH_DHCHAP_DHGROUP_NULL) { + if (tmp_dhgid != ctrl->dh_gid) { dhgid = tmp_dhgid; break; } @@ -71,7 +71,6 @@ static u16 nvmet_auth_negotiate(struct nvmet_req *req, void *d) __func__, ctrl->cntlid, req->sq->qid); return NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE; } - ctrl->dh_gid = dhgid; pr_debug("%s: ctrl %d qid %d: selected DH group %s (%d)\n", __func__, ctrl->cntlid, req->sq->qid, nvme_auth_dhgroup_name(ctrl->dh_gid), ctrl->dh_gid); @@ -90,7 +89,11 @@ static u16 nvmet_auth_reply(struct nvmet_req *req, void *d) data->hl, data->cvalid, dhvlen); if (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, + dhvlen) < 0) + return NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE; } response = kmalloc(data->hl, GFP_KERNEL); @@ -318,6 +321,8 @@ static int nvmet_auth_challenge(struct nvmet_req *req, void *d, int al) int hash_len = nvme_auth_hmac_hash_len(ctrl->shash_id); 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); @@ -336,9 +341,15 @@ 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 = cpu_to_le32(ctrl->dh_keysize); + ret = nvmet_auth_ctrl_exponential(req, data->cval + data->hl, + ctrl->dh_keysize); + } 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, 0); + req->sq->dhchap_tid, data->hl, ctrl->dh_keysize); return ret; } diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h index ef1e7f7649c7..e2864310a048 100644 --- a/drivers/nvme/target/nvmet.h +++ b/drivers/nvme/target/nvmet.h @@ -230,7 +230,10 @@ struct nvmet_ctrl { size_t dhchap_ctrl_key_len; u8 dhchap_ctrl_key_hash; u8 shash_id; + struct crypto_kpp *dh_tfm; u32 dh_gid; + u8 *dh_key; + u32 dh_keysize; #endif }; @@ -705,6 +708,7 @@ 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); @@ -714,6 +718,10 @@ static inline bool nvmet_has_auth(struct nvmet_ctrl *ctrl) { return ctrl->dhchap_key != 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) {

[11/12] nvmet-auth: Diffie-Hellman key exchange support

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