[08/13] nvme-auth: Diffie-Hellman key exchange support

Message ID	20210810124230.12161-9-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: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me>, Keith Busch <keith.busch@wdc.com>, Herbert Xu <herbert@gondor.apana.org.au>, "David S . Miller" <davem@davemloft.net>, linux-nvme@lists.infradead.org, linux-crypto@vger.kernel.org, Hannes Reinecke <hare@suse.de> Subject: [PATCH 08/13] nvme-auth: Diffie-Hellman key exchange support Date: Tue, 10 Aug 2021 14:42:25 +0200 Message-Id: <20210810124230.12161-9-hare@suse.de> In-Reply-To: <20210810124230.12161-1-hare@suse.de> References: <20210810124230.12161-1-hare@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	nvme: In-band authentication support \| expand [PATCHv2,00/13] nvme: In-band authentication support [01/13] crypto: add crypto_has_shash() [02/13] crypto: add crypto_has_kpp() [03/13] crypto/ffdhe: Finite Field DH Ephemeral Parameters [04/13] lib/base64: RFC4648-compliant base64 encoding [05/13] nvme: add definitions for NVMe In-Band authentication [06/13] nvme-fabrics: decode 'authentication required' connect error [07/13] nvme: Implement In-Band authentication [08/13] nvme-auth: Diffie-Hellman key exchange support [09/13] nvmet: Parse fabrics commands on all queues [10/13] nvmet: Implement basic In-Band Authentication [11/13] nvmet-auth: Diffie-Hellman key exchange support [12/13] nvmet-auth: expire authentication sessions [13/13] nvme: add non-standard ECDH and curve25517 algorithms

diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c index 8916755b6247..e73b5be4a4b0 100644 --- a/drivers/nvme/host/auth.c +++ b/drivers/nvme/host/auth.c @@ -36,6 +36,12 @@ struct nvme_dhchap_queue_context { u8 c2[64]; u8 response[64]; u8 *host_response; + u8 *ctrl_key; + int ctrl_key_len; + u8 *host_key; + int host_key_len; + u8 *sess_key; + int sess_key_len; }; static struct nvme_auth_dhgroup_map { @@ -611,6 +617,7 @@ static int nvme_auth_process_dhchap_challenge(struct nvme_ctrl *ctrl, struct nvmf_auth_dhchap_challenge_data *data = chap->buf; size_t size = sizeof(*data) + data->hl + data->dhvlen; const char *hmac_name; + const char *kpp_name; if (chap->buf_size < size) { chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD; @@ -665,9 +672,9 @@ static int nvme_auth_process_dhchap_challenge(struct nvme_ctrl *ctrl, chap->hash_len = data->hl; dev_dbg(ctrl->device, "qid %d: selected hash %s\n", chap->qid, hmac_name); - - gid_name = nvme_auth_dhgroup_kpp(data->dhgid); - if (!gid_name) { +select_kpp: + kpp_name = nvme_auth_dhgroup_kpp(data->dhgid); + if (!kpp_name) { dev_warn(ctrl->device, "qid %d: invalid DH group id %d\n", chap->qid, data->dhgid); @@ -676,6 +683,8 @@ static int nvme_auth_process_dhchap_challenge(struct nvme_ctrl *ctrl, } if (data->dhgid != NVME_AUTH_DHCHAP_DHGROUP_NULL) { + const char *gid_name = nvme_auth_dhgroup_name(data->dhgid); + if (data->dhvlen == 0) { dev_warn(ctrl->device, "qid %d: empty DH value\n", @@ -683,31 +692,55 @@ static int nvme_auth_process_dhchap_challenge(struct nvme_ctrl *ctrl, chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE; return -EPROTO; } - chap->dh_tfm = crypto_alloc_kpp(gid_name, 0, 0); + if (chap->dh_tfm && chap->dhgroup_id == data->dhgid) { + dev_dbg(ctrl->device, + "qid %d: reuse existing DH group %s\n", + chap->qid, gid_name); + goto skip_kpp; + } + chap->dh_tfm = crypto_alloc_kpp(kpp_name, 0, 0); if (IS_ERR(chap->dh_tfm)) { int ret = PTR_ERR(chap->dh_tfm); dev_warn(ctrl->device, - "qid %d: failed to initialize %s\n", + "qid %d: failed to initialize DH group %s\n", chap->qid, gid_name); chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE; chap->dh_tfm = NULL; return ret; } - chap->dhgroup_id = data->dhgid; - } else if (data->dhvlen != 0) { - dev_warn(ctrl->device, - "qid %d: invalid DH value for NULL DH\n", - chap->qid); - chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE; - return -EPROTO; + /* Clear host key to avoid accidental reuse */ + kfree_sensitive(chap->host_key); + chap->host_key_len = 0; + dev_dbg(ctrl->device, "qid %d: selected DH group %s\n", + chap->qid, gid_name); + } else { + if (data->dhvlen != 0) { + dev_warn(ctrl->device, + "qid %d: invalid DH value for NULL DH\n", + chap->qid); + chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE; + return -EPROTO; + } + if (chap->dh_tfm) { + crypto_free_kpp(chap->dh_tfm); + chap->dh_tfm = NULL; + } } - dev_dbg(ctrl->device, "qid %d: selected DH group %s\n", - chap->qid, gid_name); - -select_kpp: + chap->dhgroup_id = data->dhgid; +skip_kpp: chap->s1 = le32_to_cpu(data->seqnum); memcpy(chap->c1, data->cval, chap->hash_len); + if (data->dhvlen) { + chap->ctrl_key = kmalloc(data->dhvlen, GFP_KERNEL); + if (!chap->ctrl_key) + return -ENOMEM; + chap->ctrl_key_len = data->dhvlen; + memcpy(chap->ctrl_key, data->cval + chap->hash_len, + data->dhvlen); + dev_dbg(ctrl->device, "ctrl public key %*ph\n", + (int)chap->ctrl_key_len, chap->ctrl_key); + } return 0; } @@ -725,6 +758,8 @@ static int nvme_auth_set_dhchap_reply_data(struct nvme_ctrl *ctrl, } else memset(chap->c2, 0, chap->hash_len); + if (chap->host_key_len) + size += chap->host_key_len; if (chap->buf_size < size) { chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD; @@ -735,7 +770,7 @@ static int nvme_auth_set_dhchap_reply_data(struct nvme_ctrl *ctrl, data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_REPLY; data->t_id = cpu_to_le16(chap->transaction); data->hl = chap->hash_len; - data->dhvlen = 0; + data->dhvlen = chap->host_key_len; data->seqnum = cpu_to_le32(chap->s2); memcpy(data->rval, chap->response, chap->hash_len); if (ctrl->opts->dhchap_bidi) { @@ -746,6 +781,13 @@ static int nvme_auth_set_dhchap_reply_data(struct nvme_ctrl *ctrl, memcpy(data->rval + chap->hash_len, chap->c2, chap->hash_len); } + if (chap->host_key_len) { + dev_dbg(ctrl->device, "%s: qid %d host public key %*ph\n", + __func__, chap->qid, + chap->host_key_len, chap->host_key); + memcpy(data->rval + 2 * chap->hash_len, chap->host_key, + chap->host_key_len); + } return size; } @@ -832,6 +874,27 @@ static int nvme_auth_dhchap_host_response(struct nvme_ctrl *ctrl, dev_dbg(ctrl->device, "%s: qid %d host response seq %d transaction %d\n", __func__, chap->qid, chap->s1, chap->transaction); + + if (!chap->host_response) { + chap->host_response = nvme_auth_transform_key(ctrl->dhchap_key, + chap->hash_len, chap->hash_id, + ctrl->opts->host->nqn); + if (IS_ERR(chap->host_response)) { + ret = PTR_ERR(chap->host_response); + chap->host_response = NULL; + return ret; + } + } + ret = crypto_shash_setkey(chap->shash_tfm, + chap->host_response, chap->hash_len); + if (ret) { + dev_warn(ctrl->device, "qid %d: failed to set key, error %d\n", + chap->qid, ret); + goto out; + } + dev_dbg(ctrl->device, + "%s: using key %*ph\n", __func__, + (int)chap->hash_len, chap->host_response); if (chap->dh_tfm) { challenge = kmalloc(chap->hash_len, GFP_KERNEL); if (!challenge) { @@ -890,9 +953,28 @@ static int nvme_auth_dhchap_ctrl_response(struct nvme_ctrl *ctrl, struct nvme_dhchap_queue_context *chap) { SHASH_DESC_ON_STACK(shash, chap->shash_tfm); + u8 *ctrl_response; u8 buf[4], *challenge = chap->c2; int ret; + ctrl_response = nvme_auth_transform_key(ctrl->dhchap_key, + chap->hash_len, chap->hash_id, + ctrl->opts->subsysnqn); + if (IS_ERR(ctrl_response)) { + ret = PTR_ERR(ctrl_response); + return ret; + } + ret = crypto_shash_setkey(chap->shash_tfm, + ctrl_response, ctrl->dhchap_key_len); + if (ret) { + dev_warn(ctrl->device, "qid %d: failed to set key, error %d\n", + chap->qid, ret); + goto out; + } + dev_dbg(ctrl->device, + "%s: using key %*ph\n", __func__, + (int)ctrl->dhchap_key_len, ctrl_response); + if (chap->dh_tfm) { challenge = kmalloc(chap->hash_len, GFP_KERNEL); if (!challenge) { @@ -980,8 +1062,77 @@ int nvme_auth_generate_key(struct nvme_ctrl *ctrl) } EXPORT_SYMBOL_GPL(nvme_auth_generate_key); +static int nvme_auth_dhchap_exponential(struct nvme_ctrl *ctrl, + struct nvme_dhchap_queue_context *chap) +{ + int ret; + + if (chap->host_key && chap->host_key_len) { + dev_dbg(ctrl->device, + "qid %d: reusing host key\n", chap->qid); + goto gen_sesskey; + } + ret = nvme_auth_gen_privkey(chap->dh_tfm, chap->dhgroup_id); + if (ret < 0) { + chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD; + return ret; + } + + chap->host_key_len = + nvme_auth_dhgroup_pubkey_size(chap->dhgroup_id); + + chap->host_key = kzalloc(chap->host_key_len, GFP_KERNEL); + if (!chap->host_key) { + chap->host_key_len = 0; + chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED; + return -ENOMEM; + } + ret = nvme_auth_gen_pubkey(chap->dh_tfm, + chap->host_key, chap->host_key_len); + if (ret) { + dev_dbg(ctrl->device, + "failed to generate public key, error %d\n", ret); + kfree(chap->host_key); + chap->host_key = NULL; + chap->host_key_len = 0; + chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD; + return ret; + } + +gen_sesskey: + chap->sess_key_len = chap->host_key_len; + chap->sess_key = kmalloc(chap->sess_key_len, GFP_KERNEL); + if (!chap->sess_key) { + chap->sess_key_len = 0; + chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED; + return -ENOMEM; + } + + ret = nvme_auth_gen_shared_secret(chap->dh_tfm, + chap->ctrl_key, chap->ctrl_key_len, + chap->sess_key, chap->sess_key_len); + if (ret) { + dev_dbg(ctrl->device, + "failed to generate shared secret, error %d\n", ret); + kfree_sensitive(chap->sess_key); + chap->sess_key = NULL; + chap->sess_key_len = 0; + chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD; + return ret; + } + dev_dbg(ctrl->device, "shared secret %*ph\n", + (int)chap->sess_key_len, chap->sess_key); + return 0; +} + static void nvme_auth_reset(struct nvme_dhchap_queue_context *chap) { + kfree_sensitive(chap->ctrl_key); + chap->ctrl_key = NULL; + chap->ctrl_key_len = 0; + kfree_sensitive(chap->sess_key); + chap->sess_key = NULL; + chap->sess_key_len = 0; chap->status = 0; chap->error = 0; chap->s1 = 0; @@ -995,6 +1146,11 @@ static void __nvme_auth_free(struct nvme_dhchap_queue_context *chap) { if (chap->shash_tfm) crypto_free_shash(chap->shash_tfm); + if (chap->dh_tfm) + crypto_free_kpp(chap->dh_tfm); + kfree_sensitive(chap->ctrl_key); + kfree_sensitive(chap->host_key); + kfree_sensitive(chap->sess_key); kfree_sensitive(chap->host_response); kfree(chap->buf); kfree(chap); diff --git a/drivers/nvme/host/auth.h b/drivers/nvme/host/auth.h index cf1255f9db6d..aec954e9de1e 100644 --- a/drivers/nvme/host/auth.h +++ b/drivers/nvme/host/auth.h @@ -21,5 +21,13 @@ int nvme_auth_hmac_id(const char *hmac_name); unsigned char *nvme_auth_extract_secret(unsigned char *dhchap_secret, size_t *dhchap_key_len); u8 *nvme_auth_transform_key(u8 *key, size_t key_len, u8 key_hash, char *nqn); +int nvme_auth_augmented_challenge(u8 hmac_id, u8 *skey, size_t skey_len, + u8 *challenge, u8 *aug, size_t hlen); +int nvme_auth_gen_privkey(struct crypto_kpp *dh_tfm, int dh_gid); +int nvme_auth_gen_pubkey(struct crypto_kpp *dh_tfm, + u8 *host_key, size_t host_key_len); +int nvme_auth_gen_shared_secret(struct crypto_kpp *dh_tfm, + u8 *ctrl_key, size_t ctrl_key_len, + u8 *sess_key, size_t sess_key_len); #endif /* _NVME_AUTH_H */

[08/13] nvme-auth: Diffie-Hellman key exchange support

Commit Message

Patch