On 7/16/21 4:04 AM, Hannes Reinecke wrote:
Implement support for augmented challenge using FFDHE groups.
Please some more info for the change log...
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/nvme/host/auth.c | 403 +++++++++++++++++++++++++++++++++++----
1 file changed, 371 insertions(+), 32 deletions(-)
diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
index 448a3adebea6..754343aced19 100644
--- a/drivers/nvme/host/auth.c
+++ b/drivers/nvme/host/auth.c
@@ -8,6 +8,8 @@
#include <asm/unaligned.h>
#include <crypto/hash.h>
#include <crypto/kpp.h>
+#include <crypto/dh.h>
+#include <crypto/ffdhe.h>
#include "nvme.h"
#include "fabrics.h"
#include "auth.h"
@@ -16,6 +18,8 @@ static u32 nvme_dhchap_seqnum;
struct nvme_dhchap_context {
struct crypto_shash *shash_tfm;
+ struct crypto_shash *digest_tfm;
+ struct crypto_kpp *dh_tfm;
unsigned char *key;
size_t key_len;
int qid;
@@ -25,6 +29,8 @@ struct nvme_dhchap_context {
u8 status;
u8 hash_id;
u8 hash_len;
+ u8 dhgroup_id;
+ u16 dhgroup_size;
u8 c1[64];
u8 c2[64];
u8 response[64];
@@ -36,6 +42,94 @@ struct nvme_dhchap_context {
int sess_key_len;
};
+struct nvme_auth_dhgroup_map {
+ int id;
+ const char name[16];
+ const char kpp[16];
+ int privkey_size;
+ int pubkey_size;
+} dhgroup_map[] = {
+ { .id = NVME_AUTH_DHCHAP_DHGROUP_NULL,
+ .name = "NULL", .kpp = "NULL",
+ .privkey_size = 0, .pubkey_size = 0 },
+ { .id = NVME_AUTH_DHCHAP_DHGROUP_2048,
+ .name = "ffdhe2048", .kpp = "dh",
+ .privkey_size = 256, .pubkey_size = 256 },
+ { .id = NVME_AUTH_DHCHAP_DHGROUP_3072,
+ .name = "ffdhe3072", .kpp = "dh",
+ .privkey_size = 384, .pubkey_size = 384 },
+ { .id = NVME_AUTH_DHCHAP_DHGROUP_4096,
+ .name = "ffdhe4096", .kpp = "dh",
+ .privkey_size = 512, .pubkey_size = 512 },
+ { .id = NVME_AUTH_DHCHAP_DHGROUP_6144,
+ .name = "ffdhe6144", .kpp = "dh",
+ .privkey_size = 768, .pubkey_size = 768 },
+ { .id = NVME_AUTH_DHCHAP_DHGROUP_8192,
+ .name = "ffdhe8192", .kpp = "dh",
+ .privkey_size = 1024, .pubkey_size = 1024 },
+};
+
+const char *nvme_auth_dhgroup_name(int dhgroup_id)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
+ if (dhgroup_map[i].id == dhgroup_id)
+ return dhgroup_map[i].name;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_name);
+
+int nvme_auth_dhgroup_pubkey_size(int dhgroup_id)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
+ if (dhgroup_map[i].id == dhgroup_id)
+ return dhgroup_map[i].pubkey_size;
+ }
+ return -1;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_pubkey_size);
+
+int nvme_auth_dhgroup_privkey_size(int dhgroup_id)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
+ if (dhgroup_map[i].id == dhgroup_id)
+ return dhgroup_map[i].privkey_size;
+ }
+ return -1;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_privkey_size);
+
+const char *nvme_auth_dhgroup_kpp(int dhgroup_id)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
+ if (dhgroup_map[i].id == dhgroup_id)
+ return dhgroup_map[i].kpp;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_kpp);
+
+int nvme_auth_dhgroup_id(const char *dhgroup_name)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
+ if (!strncmp(dhgroup_map[i].name, dhgroup_name,
+ strlen(dhgroup_map[i].name)))
+ return dhgroup_map[i].id;
+ }
+ return -1;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_id);
+
struct nvmet_dhchap_hash_map {
int id;
int hash_len;
@@ -243,11 +337,16 @@ static int nvme_auth_dhchap_negotiate(struct nvme_ctrl *ctrl,
data->napd = 1;
data->auth_protocol[0].dhchap.authid = NVME_AUTH_DHCHAP_AUTH_ID;
data->auth_protocol[0].dhchap.halen = 3;
- data->auth_protocol[0].dhchap.dhlen = 1;
+ data->auth_protocol[0].dhchap.dhlen = 6;
data->auth_protocol[0].dhchap.idlist[0] = NVME_AUTH_DHCHAP_HASH_SHA256;
data->auth_protocol[0].dhchap.idlist[1] = NVME_AUTH_DHCHAP_HASH_SHA384;
data->auth_protocol[0].dhchap.idlist[2] = NVME_AUTH_DHCHAP_HASH_SHA512;
data->auth_protocol[0].dhchap.idlist[3] = NVME_AUTH_DHCHAP_DHGROUP_NULL;
+ data->auth_protocol[0].dhchap.idlist[4] = NVME_AUTH_DHCHAP_DHGROUP_2048;
+ data->auth_protocol[0].dhchap.idlist[5] = NVME_AUTH_DHCHAP_DHGROUP_3072;
+ data->auth_protocol[0].dhchap.idlist[6] = NVME_AUTH_DHCHAP_DHGROUP_4096;
+ data->auth_protocol[0].dhchap.idlist[7] = NVME_AUTH_DHCHAP_DHGROUP_6144;
+ data->auth_protocol[0].dhchap.idlist[8] = NVME_AUTH_DHCHAP_DHGROUP_8192;
return size;
}
@@ -274,14 +373,7 @@ static int nvme_auth_dhchap_challenge(struct nvme_ctrl *ctrl,
chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
return -EPROTO;
}
- switch (data->dhgid) {
- case NVME_AUTH_DHCHAP_DHGROUP_NULL:
- gid_name = "null";
- break;
- default:
- gid_name = NULL;
- break;
- }
+ gid_name = nvme_auth_dhgroup_kpp(data->dhgid);
if (!gid_name) {
dev_warn(ctrl->device,
"qid %d: DH-HMAC-CHAP: invalid DH group id %d\n",
@@ -290,10 +382,24 @@ static int nvme_auth_dhchap_challenge(struct nvme_ctrl *ctrl,
return -EPROTO;
}
if (data->dhgid != NVME_AUTH_DHCHAP_DHGROUP_NULL) {
- chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
- return -EPROTO;
- }
- if (data->dhgid == NVME_AUTH_DHCHAP_DHGROUP_NULL && data->dhvlen != 0) {
+ if (data->dhvlen == 0) {
+ dev_warn(ctrl->device,
+ "qid %d: DH-HMAC-CHAP: empty DH value\n",
+ chap->qid);
+ chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
+ return -EPROTO;
+ }
+ chap->dh_tfm = crypto_alloc_kpp(gid_name, 0, 0);
+ if (IS_ERR(chap->dh_tfm)) {
+ dev_warn(ctrl->device,
+ "qid %d: DH-HMAC-CHAP: failed to initialize %s\n",
+ chap->qid, gid_name);
+ chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
+ chap->dh_tfm = NULL;
+ return -EPROTO;
Why not propogate the error?
+ }
+ chap->dhgroup_id = data->dhgid;
+ } else if (data->dhvlen != 0) {
dev_warn(ctrl->device,
"qid %d: DH-HMAC-CHAP: invalid DH value for NULL DH\n",
chap->qid);
@@ -313,6 +419,16 @@ static int nvme_auth_dhchap_challenge(struct nvme_ctrl *ctrl,
chap->hash_len = data->hl;
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;
}
@@ -353,10 +469,13 @@ static int nvme_auth_dhchap_reply(struct nvme_ctrl *ctrl,
memcpy(data->rval + chap->hash_len, chap->c2,
chap->hash_len);
}
- if (chap->host_key_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);
-
+ }
Is this change only adding the debug print?
return size;
}
@@ -440,23 +559,10 @@ static int nvme_auth_dhchap_failure2(struct nvme_ctrl *ctrl,
int nvme_auth_select_hash(struct nvme_ctrl *ctrl,
struct nvme_dhchap_context *chap)
{
- char *hash_name;
+ const char *hash_name, *digest_name;
int ret;
- switch (chap->hash_id) {
- case NVME_AUTH_DHCHAP_HASH_SHA256:
- hash_name = "hmac(sha256)";
- break;
- case NVME_AUTH_DHCHAP_HASH_SHA384:
- hash_name = "hmac(sha384)";
- break;
- case NVME_AUTH_DHCHAP_HASH_SHA512:
- hash_name = "hmac(sha512)";
- break;
- default:
- hash_name = NULL;
- break;
- }
+ hash_name = nvme_auth_hmac_name(chap->hash_id);
if (!hash_name) {
chap->status = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
return -EPROTO;
@@ -468,26 +574,100 @@ int nvme_auth_select_hash(struct nvme_ctrl *ctrl,
chap->shash_tfm = NULL;
return -EPROTO;
}
+ digest_name = nvme_auth_digest_name(chap->hash_id);
+ if (!digest_name) {
+ crypto_free_shash(chap->shash_tfm);
+ chap->shash_tfm = NULL;
+ return -EPROTO;
+ }
+ chap->digest_tfm = crypto_alloc_shash(digest_name, 0, 0);
+ if (IS_ERR(chap->digest_tfm)) {
+ chap->status = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
+ crypto_free_shash(chap->shash_tfm);
+ chap->shash_tfm = NULL;
+ chap->digest_tfm = NULL;
+ return -EPROTO;
+ }
if (!chap->key) {
dev_warn(ctrl->device, "qid %d: cannot select hash, no key\n",
chap->qid);
chap->status = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
+ crypto_free_shash(chap->digest_tfm);
crypto_free_shash(chap->shash_tfm);
chap->shash_tfm = NULL;
+ chap->digest_tfm = NULL;
return -EINVAL;
Please have a structured goto targets in reverse order, this repeated
cleanup is a mess...
}
ret = crypto_shash_setkey(chap->shash_tfm, chap->key, chap->key_len);
if (ret) {
chap->status = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
+ crypto_free_shash(chap->digest_tfm);
crypto_free_shash(chap->shash_tfm);
chap->shash_tfm = NULL;
+ chap->digest_tfm = NULL;
return ret;
}
- dev_info(ctrl->device, "qid %d: DH-HMAC_CHAP: selected hash %s\n",
- chap->qid, hash_name);
+ dev_dbg(ctrl->device, "qid %d: DH-HMAC_CHAP: selected hash %s\n",
+ chap->qid, hash_name);
return 0;
}
+static int nvme_auth_augmented_challenge(struct nvme_dhchap_context *chap,
+ u8 *challenge, u8 *aug)
+{
+ struct crypto_shash *tfm;
+ struct shash_desc *desc;
+ u8 *hashed_key;
+ const char *hash_name;
+ int ret;
+
+ hashed_key = kmalloc(chap->hash_len, GFP_KERNEL);
+ if (!hashed_key)
+ return -ENOMEM;
+
+ ret = crypto_shash_tfm_digest(chap->digest_tfm, chap->sess_key,
+ chap->sess_key_len, hashed_key);
+ if (ret < 0) {
+ pr_debug("failed to hash session key, err %d\n", ret);
+ kfree(hashed_key);
Same here...
+ return ret;
+ }
Spaces between if conditions please?
+ hash_name = crypto_shash_alg_name(chap->shash_tfm);
+ if (!hash_name) {
+ pr_debug("Invalid hash algoritm\n");
+ return -EINVAL;
+ }
+ tfm = crypto_alloc_shash(hash_name, 0, 0);
+ if (IS_ERR(tfm)) {
+ ret = PTR_ERR(tfm);
+ goto out_free_key;
+ }
+ desc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm),
+ GFP_KERNEL);
+ if (!desc) {
+ ret = -ENOMEM;
+ goto out_free_hash;
+ }
+ desc->tfm = tfm;
+
+ ret = crypto_shash_setkey(tfm, hashed_key, chap->hash_len);
+ if (ret)
+ goto out_free_desc;
+ ret = crypto_shash_init(desc);
+ if (ret)
+ goto out_free_desc;
+ crypto_shash_update(desc, challenge, chap->hash_len);
+ crypto_shash_final(desc, aug);
+
+out_free_desc:
+ kfree_sensitive(desc);
+out_free_hash:
+ crypto_free_shash(tfm);
+out_free_key:
+ kfree(hashed_key);
+ return ret;
+}
+
static int nvme_auth_dhchap_host_response(struct nvme_ctrl *ctrl,
struct nvme_dhchap_context *chap)
{
@@ -497,6 +677,16 @@ 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->dh_tfm) {
+ challenge = kmalloc(chap->hash_len, GFP_KERNEL);
+ if (!challenge) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = nvme_auth_augmented_challenge(chap, chap->c1, challenge);
+ if (ret)
+ goto out;
+ }
shash->tfm = chap->shash_tfm;
ret = crypto_shash_init(shash);
if (ret)
@@ -532,6 +722,8 @@ static int nvme_auth_dhchap_host_response(struct nvme_ctrl *ctrl,
goto out;
ret = crypto_shash_final(shash, chap->response);
out:
+ if (challenge != chap->c1)
+ kfree(challenge);
return ret;
}
@@ -542,6 +734,17 @@ static int nvme_auth_dhchap_ctrl_response(struct nvme_ctrl *ctrl,
u8 buf[4], *challenge = chap->c2;
int ret;
+ if (chap->dh_tfm) {
+ challenge = kmalloc(chap->hash_len, GFP_KERNEL);
+ if (!challenge) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = nvme_auth_augmented_challenge(chap, chap->c2,
+ challenge);
+ if (ret)
+ goto out;
+ }
dev_dbg(ctrl->device, "%s: qid %d host response seq %d transaction %d\n",
__func__, chap->qid, chap->s2, chap->transaction);
dev_dbg(ctrl->device, "%s: qid %d challenge %*ph\n",
@@ -585,6 +788,8 @@ static int nvme_auth_dhchap_ctrl_response(struct nvme_ctrl *ctrl,
goto out;
ret = crypto_shash_final(shash, chap->response);
out:
+ if (challenge != chap->c2)
+ kfree(challenge);
Just free ?! what about failing?
return ret;
}
@@ -644,10 +849,134 @@ int nvme_auth_generate_key(struct nvme_ctrl *ctrl,
return 0;
}
+static int nvme_auth_dhchap_exponential(struct nvme_ctrl *ctrl,
+ struct nvme_dhchap_context *chap)
+{
+ struct kpp_request *req;
+ struct crypto_wait wait;
+ struct scatterlist src, dst;
+ u8 *pkey;
+ int ret, pkey_len;
+
+ if (chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_2048 ||
+ chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_3072 ||
+ chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_4096 ||
+ chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_6144 ||
+ chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_8192) {
+ struct dh p = {0};
+ int pubkey_size = nvme_auth_dhgroup_pubkey_size(chap->dhgroup_id);
+
+ ret = crypto_ffdhe_params(&p, pubkey_size << 3);
+ if (ret) {
+ dev_dbg(ctrl->device,
+ "failed to generate ffdhe params, error %d\n",
+ ret);
+ return ret;
+ }
+ p.key = chap->key;
+ p.key_size = chap->key_len;
+
+ pkey_len = crypto_dh_key_len(&p);
+ pkey = kzalloc(pkey_len, GFP_KERNEL);
+
+ get_random_bytes(pkey, pkey_len);
+ ret = crypto_dh_encode_key(pkey, pkey_len, &p);
+ if (ret) {
+ dev_dbg(ctrl->device,
+ "failed to encode pkey, error %d\n", ret);
+ kfree(pkey);
+ return ret;
+ }
+ chap->host_key_len = pubkey_size;
+ chap->sess_key_len = pubkey_size;
+ } else {
+ dev_warn(ctrl->device, "Invalid DH group id %d\n",
+ chap->dhgroup_id);
+ chap->status = NVME_AUTH_DHCHAP_FAILURE_INVALID_PAYLOAD;
+ return -EINVAL;
+ }
+
+ ret = crypto_kpp_set_secret(chap->dh_tfm, pkey, pkey_len);
+ if (ret) {
+ dev_dbg(ctrl->dev, "failed to set secret, error %d\n", ret);
+ kfree(pkey);
+ return ret;
+ }
+ req = kpp_request_alloc(chap->dh_tfm, GFP_KERNEL);
+ if (!req) {
+ ret = -ENOMEM;
+ goto out_free_exp;
+ }
+
+ chap->host_key = kzalloc(chap->host_key_len, GFP_KERNEL);
+ if (!chap->host_key) {
+ ret = -ENOMEM;
+ goto out_free_req;
+ }
+ crypto_init_wait(&wait);
+ kpp_request_set_input(req, NULL, 0);
+ sg_init_one(&dst, chap->host_key, chap->host_key_len);
+ kpp_request_set_output(req, &dst, chap->host_key_len);
+ kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ crypto_req_done, &wait);
+
+ ret = crypto_wait_req(crypto_kpp_generate_public_key(req), &wait);
+ if (ret == -EOVERFLOW) {
+ dev_dbg(ctrl->dev,
+ "public key buffer too small, wants %d is %d\n",
+ crypto_kpp_maxsize(chap->dh_tfm), chap->host_key_len);
+ goto out_free_host;
Is this a specific retcode of intereset? Why did you specifically add
special casing here?
+ } else if (ret) {
+ dev_dbg(ctrl->dev,
+ "failed to generate public key, error %d\n", ret);
+ goto out_free_host;
+ }
+
+ chap->sess_key = kmalloc(chap->sess_key_len, GFP_KERNEL);
+ if (!chap->sess_key)
+ goto out_free_host;
+
+ crypto_init_wait(&wait);
+ sg_init_one(&src, chap->ctrl_key, chap->ctrl_key_len);
+ kpp_request_set_input(req, &src, chap->ctrl_key_len);
+ sg_init_one(&dst, chap->sess_key, chap->sess_key_len);
+ kpp_request_set_output(req, &dst, chap->sess_key_len);
+ kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ crypto_req_done, &wait);
+
+ ret = crypto_wait_req(crypto_kpp_compute_shared_secret(req), &wait);
+ if (ret) {
+ dev_dbg(ctrl->dev,
+ "failed to generate shared secret, error %d\n", ret);
+ kfree_sensitive(chap->sess_key);
+ chap->sess_key = NULL;
+ chap->sess_key_len = 0;
+ } else
+ dev_dbg(ctrl->dev, "shared secret %*ph\n",
+ (int)chap->sess_key_len, chap->sess_key);
+out_free_host:
+ if (ret) {
+ kfree(chap->host_key);
+ chap->host_key = NULL;
+ chap->host_key_len = 0;
+ }
+out_free_req:
+ kpp_request_free(req);
+out_free_exp:
+ kfree_sensitive(pkey);
+ if (ret)
+ chap->status = NVME_AUTH_DHCHAP_FAILURE_INVALID_PAYLOAD;
+ return ret;
+}
+
void nvme_auth_free(struct nvme_dhchap_context *chap)
{
if (chap->shash_tfm)
crypto_free_shash(chap->shash_tfm);
+ if (chap->digest_tfm)
+ crypto_free_shash(chap->digest_tfm);
+ if (chap->dh_tfm)
+ crypto_free_kpp(chap->dh_tfm);
if (chap->key)
kfree(chap->key);
if (chap->ctrl_key)
@@ -732,6 +1061,15 @@ int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
if (ret)
goto fail2;
+ if (chap->ctrl_key_len) {
+ dev_dbg(ctrl->device,
+ "%s: qid %d DH-HMAC-DHAP DH exponential\n",
+ __func__, qid);
+ ret = nvme_auth_dhchap_exponential(ctrl, chap);
+ if (ret)
+ goto fail2;
+ }
+
dev_dbg(ctrl->device, "%s: qid %d DH-HMAC-CHAP host response\n",
__func__, qid);
ret = nvme_auth_dhchap_host_response(ctrl, chap);
@@ -806,6 +1144,7 @@ int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
ret = -EPROTO;
if (!ret) {
ctrl->dhchap_hash = chap->hash_id;
+ ctrl->dhchap_dhgroup = chap->dhgroup_id;
}
kfree(buf);
nvme_auth_free(chap);
