[PATCH 11/11] nvme: add non-standard ECDH and curve25517 algorithms

[Hannes Reinecke <hare@suse.de>]

TLS 1.3 specifies ECDH and curve25517 in addition to the FFDHE
groups, and these are already implemented in the kernel.
So add support for these non-standard groups for NVMe in-band
authentication to validate the augmented challenge implementation.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/nvme/host/auth.c   | 38 +++++++++++++++++++++++++++++++++++++-
 drivers/nvme/target/auth.c | 23 +++++++++++++++++++++++
 include/linux/nvme.h       |  2 ++
 3 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
index 754343aced19..d0dd63b455ef 100644
--- a/drivers/nvme/host/auth.c
+++ b/drivers/nvme/host/auth.c
@@ -10,6 +10,8 @@
 #include <crypto/kpp.h>
 #include <crypto/dh.h>
 #include <crypto/ffdhe.h>
+#include <crypto/ecdh.h>
+#include <crypto/curve25519.h>
 #include "nvme.h"
 #include "fabrics.h"
 #include "auth.h"
@@ -67,6 +69,13 @@ struct nvme_auth_dhgroup_map {
 	{ .id = NVME_AUTH_DHCHAP_DHGROUP_8192,
 	  .name = "ffdhe8192", .kpp = "dh",
 	  .privkey_size = 1024, .pubkey_size = 1024 },
+	{ .id = NVME_AUTH_DHCHAP_DHGROUP_ECDH,
+	  .name = "ecdh", .kpp = "ecdh-nist-p256",
+	  .privkey_size = 32, .pubkey_size = 64 },
+	{ .id = NVME_AUTH_DHCHAP_DHGROUP_25519,
+	  .name = "curve25519", .kpp = "curve25519",
+	  .privkey_size = CURVE25519_KEY_SIZE,
+	  .pubkey_size = CURVE25519_KEY_SIZE },
 };
 
 const char *nvme_auth_dhgroup_name(int dhgroup_id)
@@ -337,7 +346,7 @@ 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 = 6;
+	data->auth_protocol[0].dhchap.dhlen = 8;
 	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;
@@ -347,6 +356,8 @@ static int nvme_auth_dhchap_negotiate(struct nvme_ctrl *ctrl,
 	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;
+	data->auth_protocol[0].dhchap.idlist[9] = NVME_AUTH_DHCHAP_DHGROUP_ECDH;
+	data->auth_protocol[0].dhchap.idlist[10] = NVME_AUTH_DHCHAP_DHGROUP_25519;
 
 	return size;
 }
@@ -889,6 +900,31 @@ static int nvme_auth_dhchap_exponential(struct nvme_ctrl *ctrl,
 		}
 		chap->host_key_len = pubkey_size;
 		chap->sess_key_len = pubkey_size;
+	} else if (chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_ECDH) {
+		struct ecdh p = {0};
+
+		pkey_len = crypto_ecdh_key_len(&p);
+		pkey = kzalloc(pkey_len, GFP_KERNEL);
+		if (!pkey)
+			return -ENOMEM;
+
+		get_random_bytes(pkey, pkey_len);
+		ret = crypto_ecdh_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 = 64;
+		chap->sess_key_len = 32;
+	} else if (chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_25519) {
+		pkey_len = CURVE25519_KEY_SIZE;
+		pkey = kzalloc(pkey_len, GFP_KERNEL);
+		if (!pkey)
+			return -ENOMEM;
+		get_random_bytes(pkey, pkey_len);
+		chap->host_key_len = chap->sess_key_len = CURVE25519_KEY_SIZE;
 	} else {
 		dev_warn(ctrl->device, "Invalid DH group id %d\n",
 			 chap->dhgroup_id);
diff --git a/drivers/nvme/target/auth.c b/drivers/nvme/target/auth.c
index cc7f12a7c8bf..7e3b613cb08b 100644
--- a/drivers/nvme/target/auth.c
+++ b/drivers/nvme/target/auth.c
@@ -13,6 +13,8 @@
 #include <crypto/kpp.h>
 #include <crypto/dh.h>
 #include <crypto/ffdhe.h>
+#include <crypto/ecdh.h>
+#include <crypto/curve25519.h>
 #include <linux/crc32.h>
 #include <linux/base64.h>
 #include <linux/ctype.h>
@@ -498,6 +500,27 @@ int nvmet_auth_ctrl_exponential(struct nvmet_req *req,
 				 ret);
 			goto out;
 		}
+	} else if (ctrl->dh_gid == NVME_AUTH_DHCHAP_DHGROUP_ECDH) {
+		struct ecdh p = {0};
+
+		pkey_len = crypto_ecdh_key_len(&p);
+		pkey = kmalloc(pkey_len, GFP_KERNEL);
+		if (!pkey)
+			return -ENOMEM;
+
+		get_random_bytes(pkey, pkey_len);
+		ret = crypto_ecdh_encode_key(pkey, pkey_len, &p);
+		if (ret) {
+			pr_debug("failed to encode private key, error %d\n",
+				 ret);
+			goto out;
+		}
+	} else if (ctrl->dh_gid == NVME_AUTH_DHCHAP_DHGROUP_25519) {
+		pkey_len = CURVE25519_KEY_SIZE;
+		pkey = kmalloc(pkey_len, GFP_KERNEL);
+		if (!pkey)
+			return -ENOMEM;
+		get_random_bytes(pkey, pkey_len);
 	} else {
 		pr_warn("invalid dh group %d\n", ctrl->dh_gid);
 		return -EINVAL;
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 7b94abacfd08..75b638adbca1 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -1476,6 +1476,8 @@ enum {
 	NVME_AUTH_DHCHAP_DHGROUP_4096	= 0x03,
 	NVME_AUTH_DHCHAP_DHGROUP_6144	= 0x04,
 	NVME_AUTH_DHCHAP_DHGROUP_8192	= 0x05,
+	NVME_AUTH_DHCHAP_DHGROUP_ECDH   = 0x0e,
+	NVME_AUTH_DHCHAP_DHGROUP_25519  = 0x0f,
 };
 
 union nvmf_auth_protocol {
-- 
2.29.2