Thread (33 messages) 33 messages, 3 authors, 2021-11-16

Re: [PATCH 07/12] nvme: Implement In-Band authentication

From: Hannes Reinecke <hare@suse.de>
Date: 2021-11-16 10:40:44
Also in: linux-nvme

On 11/16/21 11:25 AM, Sagi Grimberg wrote:

On 11/12/21 2:59 PM, Hannes Reinecke wrote:
quoted
Implement NVMe-oF In-Band authentication according to NVMe TPAR 8006.
This patch adds two new fabric options 'dhchap_secret' to specify the
pre-shared key (in ASCII respresentation according to NVMe 2.0 section
8.13.5.8 'Secret representation') and 'dhchap_ctrl_secret' to specify
the pre-shared controller key for bi-directional authentication of both
the host and the controller.
Re-authentication can be triggered by writing the PSK into the new
controller sysfs attribute 'dhchap_secret' or 'dhchap_ctrl_secret'.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
  drivers/nvme/host/Kconfig   |   11 +
  drivers/nvme/host/Makefile  |    1 +
  drivers/nvme/host/auth.c    | 1164 +++++++++++++++++++++++++++++++++++
  drivers/nvme/host/auth.h    |   25 +
  drivers/nvme/host/core.c    |  133 +++-
  drivers/nvme/host/fabrics.c |   79 ++-
  drivers/nvme/host/fabrics.h |    7 +
  drivers/nvme/host/nvme.h    |   36 ++
  drivers/nvme/host/tcp.c     |    1 +
  drivers/nvme/host/trace.c   |   32 +
  10 files changed, 1482 insertions(+), 7 deletions(-)
  create mode 100644 drivers/nvme/host/auth.c
  create mode 100644 drivers/nvme/host/auth.h
diff --git a/drivers/nvme/host/Kconfig b/drivers/nvme/host/Kconfig
index dc0450ca23a3..49269c581ec4 100644
--- a/drivers/nvme/host/Kconfig
+++ b/drivers/nvme/host/Kconfig
@@ -83,3 +83,14 @@ config NVME_TCP
        from https://github.com/linux-nvme/nvme-cli.
          If unsure, say N.
+
+config NVME_AUTH
+    bool "NVM Express over Fabrics In-Band Authentication"
+    depends on NVME_CORE
+    select CRYPTO_HMAC
+    select CRYPTO_SHA256
+    select CRYPTO_SHA512
+    help
+      This provides support for NVMe over Fabrics In-Band
Authentication.
+
+      If unsure, say N.
diff --git a/drivers/nvme/host/Makefile b/drivers/nvme/host/Makefile
index dfaacd472e5d..4bae2a4a8d8c 100644
--- a/drivers/nvme/host/Makefile
+++ b/drivers/nvme/host/Makefile
@@ -15,6 +15,7 @@ nvme-core-$(CONFIG_NVME_MULTIPATH)    += multipath.o
  nvme-core-$(CONFIG_BLK_DEV_ZONED)    += zns.o
  nvme-core-$(CONFIG_FAULT_INJECTION_DEBUG_FS)    += fault_inject.o
  nvme-core-$(CONFIG_NVME_HWMON)        += hwmon.o
+nvme-core-$(CONFIG_NVME_AUTH)        += auth.o
    nvme-y                    += pci.o
  diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
new file mode 100644
index 000000000000..6ab95a178213
--- /dev/null
+++ b/drivers/nvme/host/auth.c
@@ -0,0 +1,1164 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Hannes Reinecke, SUSE Linux
+ */
+
+#include <linux/crc32.h>
+#include <linux/base64.h>
+#include <asm/unaligned.h>
+#include <crypto/hash.h>
+#include <crypto/dh.h>
+#include <crypto/ffdhe.h>
+#include "nvme.h"
+#include "fabrics.h"
+#include "auth.h"
+
+static atomic_t nvme_dhchap_seqnum = ATOMIC_INIT(0);
+
+struct nvme_dhchap_queue_context {
+    struct list_head entry;
+    struct work_struct auth_work;
+    struct nvme_ctrl *ctrl;
+    struct crypto_shash *shash_tfm;
+    void *buf;
+    size_t buf_size;
+    int qid;
+    int error;
+    u32 s1;
+    u32 s2;
+    u16 transaction;
+    u8 status;
+    u8 hash_id;
+    u8 hash_len;
+    u8 dhgroup_id;
+    u8 c1[64];
+    u8 c2[64];
+    u8 response[64];
+    u8 *host_response;
+};
+
+static 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);
+
+static struct nvme_dhchap_hash_map {
+    int id;
+    int len;
+    const char hmac[15];
+    const char digest[15];
+} hash_map[] = {
+    {.id = NVME_AUTH_DHCHAP_SHA256, .len = 32,
+     .hmac = "hmac(sha256)", .digest = "sha256" },
+    {.id = NVME_AUTH_DHCHAP_SHA384, .len = 48,
+     .hmac = "hmac(sha384)", .digest = "sha384" },
+    {.id = NVME_AUTH_DHCHAP_SHA512, .len = 64,
+     .hmac = "hmac(sha512)", .digest = "sha512" },
+};
+
+const char *nvme_auth_hmac_name(int hmac_id)
+{
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(hash_map); i++) {
+        if (hash_map[i].id == hmac_id)
+            return hash_map[i].hmac;
+    }
+    return NULL;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_hmac_name);
+
+const char *nvme_auth_digest_name(int hmac_id)
+{
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(hash_map); i++) {
+        if (hash_map[i].id == hmac_id)
+            return hash_map[i].digest;
+    }
+    return NULL;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_digest_name);
+
+int nvme_auth_hmac_id(const char *hmac_name)
+{
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(hash_map); i++) {
+        if (!strncmp(hash_map[i].hmac, hmac_name,
+                 strlen(hash_map[i].hmac)))
+            return hash_map[i].id;
+    }
+    return -1;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_hmac_id);
+
+int nvme_auth_hmac_hash_len(int hmac_id)
+{
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(hash_map); i++) {
+        if (hash_map[i].id == hmac_id)
+            return hash_map[i].len;
+    }
+    return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_hmac_hash_len);
+
+unsigned char *nvme_auth_extract_secret(unsigned char *secret, u8
key_hash,
+                    size_t *out_len)
+{
+    unsigned char *key, *p;
+    u32 crc;
+    int key_len;
+    size_t allocated_len = strlen(secret);
+
+    /* Secret might be affixed with a ':' */
+    p = strrchr(secret, ':');
+    if (p)
+        allocated_len = p - secret;
+    key = kzalloc(allocated_len, GFP_KERNEL);
+    if (!key)
+        return ERR_PTR(-ENOMEM);
+
+    key_len = base64_decode(secret, allocated_len, key);
+    if (key_len < 0) {
+        pr_debug("base64 key decoding error %d\n",
+             key_len);
+        return ERR_PTR(key_len);
+    }
+    if (key_len != 36 && key_len != 52 &&
+        key_len != 68) {
+        pr_debug("Invalid key len %d\n",
+             key_len);
pr_err?
Yeah; I've been running with debug enabled, so I would've seen it anyway.
quoted
+        kfree_sensitive(key);
+        return ERR_PTR(-EINVAL);
+    }
+    if (key_hash > 0 &&
+        (key_len - 4) != nvme_auth_hmac_hash_len(key_hash)) {
+        pr_debug("Invalid key len %d for %s\n", key_len,
+             nvme_auth_hmac_name(key_hash));
pr_err?
Same; will be fixing it.
quoted
+        kfree_sensitive(key);
+        return ERR_PTR(-EINVAL);
+    }
+
+    /* The last four bytes is the CRC in little-endian format */
+    key_len -= 4;
+    /*
+     * The linux implementation doesn't do pre- and post-increments,
+     * so we have to do it manually.
+     */
+    crc = ~crc32(~0, key, key_len);
+
+    if (get_unaligned_le32(key + key_len) != crc) {
+        pr_debug("DH-HMAC-CHAP key crc mismatch (key %08x, crc %08x)\n",
+               get_unaligned_le32(key + key_len), crc);
pr_err?
quoted
+        kfree_sensitive(key);
+        return ERR_PTR(-EKEYREJECTED);
+    }
+    *out_len = key_len;
+    return key;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_extract_secret);
+
+u8 *nvme_auth_transform_key(u8 *key, size_t key_len, u8 key_hash,
char *nqn)
+{
+    const char *hmac_name = nvme_auth_hmac_name(key_hash);
+    struct crypto_shash *key_tfm;
+    struct shash_desc *shash;
+    u8 *transformed_key;
+    int ret;
+
+    if (key_hash == 0) {
+        transformed_key = kmemdup(key, key_len, GFP_KERNEL);
+        return transformed_key ? transformed_key : ERR_PTR(-ENOMEM);
+    }
+
+    if (!key || !key_len) {
+        pr_warn("No key specified\n");
pr_err?
quoted
+        return ERR_PTR(-ENOKEY);
+    }
+    if (!hmac_name) {
+        pr_warn("Invalid key hash id %d\n", key_hash);
pr_err?
quoted
+        return ERR_PTR(-EINVAL);
+    }
+
+    key_tfm = crypto_alloc_shash(hmac_name, 0, 0);
+    if (IS_ERR(key_tfm))
+        return (u8 *)key_tfm;
+
+    shash = kmalloc(sizeof(struct shash_desc) +
+            crypto_shash_descsize(key_tfm),
+            GFP_KERNEL);
+    if (!shash) {
+        ret = -ENOMEM;
+        goto out_free_key;
+    }
+
+    transformed_key = kzalloc(crypto_shash_digestsize(key_tfm),
GFP_KERNEL);
+    if (!transformed_key) {
+        ret = -ENOMEM;
+        goto out_free_shash;
+    }
+
+    shash->tfm = key_tfm;
+    ret = crypto_shash_setkey(key_tfm, key, key_len);
+    if (ret < 0)
+        goto out_free_shash;
+    ret = crypto_shash_init(shash);
+    if (ret < 0)
+        goto out_free_shash;
+    ret = crypto_shash_update(shash, nqn, strlen(nqn));
+    if (ret < 0)
+        goto out_free_shash;
+    ret = crypto_shash_update(shash, "NVMe-over-Fabrics", 17);
+    if (ret < 0)
+        goto out_free_shash;
+    ret = crypto_shash_final(shash, transformed_key);
+out_free_shash:
+    kfree(shash);
+out_free_key:
+    crypto_free_shash(key_tfm);
+    if (ret < 0) {
+        kfree_sensitive(transformed_key);
+        return ERR_PTR(ret);
+    }
+    return transformed_key;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_transform_key);
+
+static int nvme_auth_send(struct nvme_ctrl *ctrl, int qid,
+        void *data, size_t tl)
+{
+    struct nvme_command cmd = {};
+    blk_mq_req_flags_t flags = qid == NVME_QID_ANY ?
+        0 : BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED;
+    struct request_queue *q = qid == NVME_QID_ANY ?
+        ctrl->fabrics_q : ctrl->connect_q;
+    int ret;
+
+    cmd.auth_send.opcode = nvme_fabrics_command;
+    cmd.auth_send.fctype = nvme_fabrics_type_auth_send;
+    cmd.auth_send.secp = NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER;
+    cmd.auth_send.spsp0 = 0x01;
+    cmd.auth_send.spsp1 = 0x01;
+    cmd.auth_send.tl = cpu_to_le32(tl);
+
+    ret = __nvme_submit_sync_cmd(q, &cmd, NULL, data, tl, 0, qid,
+                     0, flags);
+    if (ret > 0)
+        dev_dbg(ctrl->device,
+            "%s: qid %d nvme status %d\n", __func__, qid, ret);
dev_err? Also can we phrase "failed auth_send" instead of the __func__?
Yeah; the logging messages are inconsistent as it is.
I've tried to stick the __func__ argument to any debug messages, and
some human readable string for 'normal' errors.
Possibly not that consistent, though.
quoted
+    else if (ret < 0)
+        dev_dbg(ctrl->device,
+            "%s: qid %d error %d\n", __func__, qid, ret);
dev_err?
quoted
+    return ret;
+}
+
+static int nvme_auth_receive(struct nvme_ctrl *ctrl, int qid,
+        void *buf, size_t al)
+{
+    struct nvme_command cmd = {};
+    blk_mq_req_flags_t flags = qid == NVME_QID_ANY ?
+        0 : BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED;
+    struct request_queue *q = qid == NVME_QID_ANY ?
+        ctrl->fabrics_q : ctrl->connect_q;
+    int ret;
+
+    cmd.auth_receive.opcode = nvme_fabrics_command;
+    cmd.auth_receive.fctype = nvme_fabrics_type_auth_receive;
+    cmd.auth_receive.secp = NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER;
+    cmd.auth_receive.spsp0 = 0x01;
+    cmd.auth_receive.spsp1 = 0x01;
+    cmd.auth_receive.al = cpu_to_le32(al);
+
+    ret = __nvme_submit_sync_cmd(q, &cmd, NULL, buf, al, 0, qid,
+                     0, flags);
+    if (ret > 0) {
+        dev_dbg(ctrl->device, "%s: qid %d nvme status %x\n",
+            __func__, qid, ret);
dev_err? "failed auth_recv" instead of the __func__
quoted
+        ret = -EIO;
+    }
+    if (ret < 0) {
+        dev_dbg(ctrl->device, "%s: qid %d error %d\n",
+            __func__, qid, ret);
dev_err
quoted
+        return ret;
+    }
+
+    return 0;
+}
+
+static int nvme_auth_receive_validate(struct nvme_ctrl *ctrl, int qid,
+        struct nvmf_auth_dhchap_failure_data *data,
+        u16 transaction, u8 expected_msg)
+{
+    dev_dbg(ctrl->device, "%s: qid %d auth_type %d auth_id %x\n",
+        __func__, qid, data->auth_type, data->auth_id);
+
+    if (data->auth_type == NVME_AUTH_COMMON_MESSAGES &&
+        data->auth_id == NVME_AUTH_DHCHAP_MESSAGE_FAILURE1) {
+        return data->rescode_exp;
+    }
+    if (data->auth_type != NVME_AUTH_DHCHAP_MESSAGES ||
+        data->auth_id != expected_msg) {
+        dev_warn(ctrl->device,
+             "qid %d invalid message %02x/%02x\n",
+             qid, data->auth_type, data->auth_id);
+        return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_MESSAGE;
+    }
+    if (le16_to_cpu(data->t_id) != transaction) {
+        dev_warn(ctrl->device,
+             "qid %d invalid transaction ID %d\n",
+             qid, le16_to_cpu(data->t_id));
why not dev_err?
Because it's a protocol error, and we can invoke the protocol error
handling here.
Any dev_err() messages are inhibiting us to run the protocol at all.
Or, at least, that's how I tried to handle things.
quoted
+        return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_MESSAGE;
+    }
+    return 0;
+}
+
+static int nvme_auth_set_dhchap_negotiate_data(struct nvme_ctrl *ctrl,
+        struct nvme_dhchap_queue_context *chap)
+{
+    struct nvmf_auth_dhchap_negotiate_data *data = chap->buf;
+    size_t size = sizeof(*data) + sizeof(union nvmf_auth_protocol);
+
+    if (chap->buf_size < size) {
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+        return -EINVAL;
+    }
+    memset((u8 *)chap->buf, 0, size);
+    data->auth_type = NVME_AUTH_COMMON_MESSAGES;
+    data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_NEGOTIATE;
+    data->t_id = cpu_to_le16(chap->transaction);
+    data->sc_c = 0; /* No secure channel concatenation */
+    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.idlist[0] = NVME_AUTH_DHCHAP_SHA256;
+    data->auth_protocol[0].dhchap.idlist[1] = NVME_AUTH_DHCHAP_SHA384;
+    data->auth_protocol[0].dhchap.idlist[2] = NVME_AUTH_DHCHAP_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;
+}
+
+static int nvme_auth_process_dhchap_challenge(struct nvme_ctrl *ctrl,
+        struct nvme_dhchap_queue_context *chap)
+{
+    struct nvmf_auth_dhchap_challenge_data *data = chap->buf;
+    u16 dhvlen = le16_to_cpu(data->dhvlen);
+    size_t size = sizeof(*data) + data->hl + dhvlen;
+    const char *hmac_name, *kpp_name;
+
+    if (chap->buf_size < size) {
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+        return NVME_SC_INVALID_FIELD;
+    }
+
+    hmac_name = nvme_auth_hmac_name(data->hashid);
+    if (!hmac_name) {
+        dev_warn(ctrl->device,
+             "qid %d: invalid HASH ID %d\n",
+             chap->qid, data->hashid);
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
+        return NVME_SC_INVALID_FIELD;
+    }
+
+    if (chap->hash_id == data->hashid && chap->shash_tfm &&
+        !strcmp(crypto_shash_alg_name(chap->shash_tfm), hmac_name) &&
+        crypto_shash_digestsize(chap->shash_tfm) == data->hl) {
+        dev_dbg(ctrl->device,
+            "qid %d: reuse existing hash %s\n",
+            chap->qid, hmac_name);
+        goto select_kpp;
+    }
+
+    /* Reset if hash cannot be reused */
+    if (chap->shash_tfm) {
+        crypto_free_shash(chap->shash_tfm);
+        chap->hash_id = 0;
+        chap->hash_len = 0;
+    }
+    chap->shash_tfm = crypto_alloc_shash(hmac_name, 0,
+                         CRYPTO_ALG_ALLOCATES_MEMORY);
+    if (IS_ERR(chap->shash_tfm)) {
+        dev_warn(ctrl->device,
+             "qid %d: failed to allocate hash %s, error %ld\n",
+             chap->qid, hmac_name, PTR_ERR(chap->shash_tfm));
+        chap->shash_tfm = NULL;
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
+        return NVME_SC_AUTH_REQUIRED;
+    }
+
+    if (crypto_shash_digestsize(chap->shash_tfm) != data->hl) {
+        dev_warn(ctrl->device,
+             "qid %d: invalid hash length %d\n",
+             chap->qid, data->hl);
+        crypto_free_shash(chap->shash_tfm);
+        chap->shash_tfm = NULL;
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
+        return NVME_SC_AUTH_REQUIRED;
+    }
+
+    /* Reset host response if the hash had been changed */
+    if (chap->hash_id != data->hashid) {
+        kfree(chap->host_response);
+        chap->host_response = NULL;
+    }
+
+    chap->hash_id = data->hashid;
+    chap->hash_len = data->hl;
+    dev_dbg(ctrl->device, "qid %d: selected hash %s\n",
+        chap->qid, hmac_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);
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
+        return NVME_SC_AUTH_REQUIRED;
+    }
+
+    if (data->dhgid != NVME_AUTH_DHCHAP_DHGROUP_NULL) {
+        dev_warn(ctrl->device,
+             "qid %d: unsupported DH group %s\n",
+             chap->qid, kpp_name);
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
+        return NVME_SC_AUTH_REQUIRED;
+    } else if (dhvlen != 0) {
+        dev_warn(ctrl->device,
+             "qid %d: invalid DH value for NULL DH\n",
+             chap->qid);
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+        return NVME_SC_INVALID_FIELD;
+    }
+    chap->dhgroup_id = data->dhgid;
+
+    chap->s1 = le32_to_cpu(data->seqnum);
+    memcpy(chap->c1, data->cval, chap->hash_len);
+
+    return 0;
+}
+
+static int nvme_auth_set_dhchap_reply_data(struct nvme_ctrl *ctrl,
+        struct nvme_dhchap_queue_context *chap)
+{
+    struct nvmf_auth_dhchap_reply_data *data = chap->buf;
+    size_t size = sizeof(*data);
+
+    size += 2 * chap->hash_len;
+
+    if (chap->buf_size < size) {
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+        return -EINVAL;
+    }
+
+    memset(chap->buf, 0, size);
+    data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
+    data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_REPLY;
+    data->t_id = cpu_to_le16(chap->transaction);
+    data->hl = chap->hash_len;
+    data->dhvlen = 0;
+    memcpy(data->rval, chap->response, chap->hash_len);
+    if (ctrl->opts->dhchap_ctrl_secret) {
+        get_random_bytes(chap->c2, chap->hash_len);
+        data->cvalid = 1;
+        chap->s2 = atomic_inc_return(&nvme_dhchap_seqnum);
+        memcpy(data->rval + chap->hash_len, chap->c2,
+               chap->hash_len);
+        dev_dbg(ctrl->device, "%s: qid %d ctrl challenge %*ph\n",
+            __func__, chap->qid,
+            chap->hash_len, chap->c2);
+    } else {
+        memset(chap->c2, 0, chap->hash_len);
+        chap->s2 = 0;
+    }
+    data->seqnum = cpu_to_le32(chap->s2);
+    return size;
+}
+
+static int nvme_auth_process_dhchap_success1(struct nvme_ctrl *ctrl,
+        struct nvme_dhchap_queue_context *chap)
+{
+    struct nvmf_auth_dhchap_success1_data *data = chap->buf;
+    size_t size = sizeof(*data);
+
+    if (ctrl->opts->dhchap_ctrl_secret)
+        size += chap->hash_len;
+
+    if (chap->buf_size < size) {
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+        return NVME_SC_INVALID_FIELD;
+    }
+
+    if (data->hl != chap->hash_len) {
+        dev_warn(ctrl->device,
+             "qid %d: invalid hash length %d\n",
+             chap->qid, data->hl);
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
+        return NVME_SC_INVALID_FIELD;
+    }
+
+    /* Just print out information for the admin queue */
+    if (chap->qid == -1)
+        dev_info(ctrl->device,
+             "qid 0: authenticated with hash %s dhgroup %s\n",
+             nvme_auth_hmac_name(chap->hash_id),
+             nvme_auth_dhgroup_name(chap->dhgroup_id));
+
+    if (!data->rvalid)
+        return 0;
+
+    /* Validate controller response */
+    if (memcmp(chap->response, data->rval, data->hl)) {
+        dev_dbg(ctrl->device, "%s: qid %d ctrl response %*ph\n",
+            __func__, chap->qid, chap->hash_len, data->rval);
+        dev_dbg(ctrl->device, "%s: qid %d host response %*ph\n",
+            __func__, chap->qid, chap->hash_len, chap->response);
+        dev_warn(ctrl->device,
+             "qid %d: controller authentication failed\n",
+             chap->qid);
+        chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
+        return NVME_SC_AUTH_REQUIRED;
+    }
+
+    /* Just print out information for the admin queue */
+    if (chap->qid == -1)
+        dev_info(ctrl->device,
+             "qid 0: controller authenticated\n");
+    return 0;
+}
+
+static int nvme_auth_set_dhchap_success2_data(struct nvme_ctrl *ctrl,
+        struct nvme_dhchap_queue_context *chap)
+{
+    struct nvmf_auth_dhchap_success2_data *data = chap->buf;
+    size_t size = sizeof(*data);
+
+    memset(chap->buf, 0, size);
+    data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
+    data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2;
+    data->t_id = cpu_to_le16(chap->transaction);
+
+    return size;
+}
+
+static int nvme_auth_set_dhchap_failure2_data(struct nvme_ctrl *ctrl,
+        struct nvme_dhchap_queue_context *chap)
+{
+    struct nvmf_auth_dhchap_failure_data *data = chap->buf;
+    size_t size = sizeof(*data);
+
+    memset(chap->buf, 0, size);
+    data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
+    data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_FAILURE2;
+    data->t_id = cpu_to_le16(chap->transaction);
+    data->rescode = NVME_AUTH_DHCHAP_FAILURE_REASON_FAILED;
+    data->rescode_exp = chap->status;
+
+    return size;
+}
+
+static int nvme_auth_dhchap_host_response(struct nvme_ctrl *ctrl,
+        struct nvme_dhchap_queue_context *chap)
+{
+    SHASH_DESC_ON_STACK(shash, chap->shash_tfm);
+    u8 buf[4], *challenge = chap->c1;
+    int ret;
+
+    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,
+                    ctrl->dhchap_key_len,
+                    ctrl->dhchap_key_hash,
+                    ctrl->opts->host->nqn);
+        if (IS_ERR(chap->host_response)) {
+            ret = PTR_ERR(chap->host_response);
+            chap->host_response = NULL;
+            return ret;
+        }
+    } else {
+        dev_dbg(ctrl->device, "%s: qid %d re-using host response\n",
+            __func__, chap->qid);
+    }
+
+    ret = crypto_shash_setkey(chap->shash_tfm,
+            chap->host_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;
+    }
+
+    shash->tfm = chap->shash_tfm;
+    ret = crypto_shash_init(shash);
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, challenge, chap->hash_len);
+    if (ret)
+        goto out;
+    put_unaligned_le32(chap->s1, buf);
+    ret = crypto_shash_update(shash, buf, 4);
+    if (ret)
+        goto out;
+    put_unaligned_le16(chap->transaction, buf);
+    ret = crypto_shash_update(shash, buf, 2);
+    if (ret)
+        goto out;
+    memset(buf, 0, sizeof(buf));
+    ret = crypto_shash_update(shash, buf, 1);
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, "HostHost", 8);
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, ctrl->opts->host->nqn,
+                  strlen(ctrl->opts->host->nqn));
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, buf, 1);
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, ctrl->opts->subsysnqn,
+                strlen(ctrl->opts->subsysnqn));
+    if (ret)
+        goto out;
+    ret = crypto_shash_final(shash, chap->response);
+out:
+    if (challenge != chap->c1)
+        kfree(challenge);
+    return ret;
+}
+
+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_ctrl_key,
+                ctrl->dhchap_ctrl_key_len,
+                ctrl->dhchap_ctrl_key_hash,
+                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_ctrl_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: 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",
+        __func__, chap->qid, chap->hash_len, challenge);
+    dev_dbg(ctrl->device, "%s: qid %d subsysnqn %s\n",
+        __func__, chap->qid, ctrl->opts->subsysnqn);
+    dev_dbg(ctrl->device, "%s: qid %d hostnqn %s\n",
+        __func__, chap->qid, ctrl->opts->host->nqn);
+    shash->tfm = chap->shash_tfm;
+    ret = crypto_shash_init(shash);
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, challenge, chap->hash_len);
+    if (ret)
+        goto out;
+    put_unaligned_le32(chap->s2, buf);
+    ret = crypto_shash_update(shash, buf, 4);
+    if (ret)
+        goto out;
+    put_unaligned_le16(chap->transaction, buf);
+    ret = crypto_shash_update(shash, buf, 2);
+    if (ret)
+        goto out;
+    memset(buf, 0, 4);
+    ret = crypto_shash_update(shash, buf, 1);
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, "Controller", 10);
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, ctrl->opts->subsysnqn,
+                  strlen(ctrl->opts->subsysnqn));
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, buf, 1);
+    if (ret)
+        goto out;
+    ret = crypto_shash_update(shash, ctrl->opts->host->nqn,
+                  strlen(ctrl->opts->host->nqn));
+    if (ret)
+        goto out;
+    ret = crypto_shash_final(shash, chap->response);
+out:
+    if (challenge != chap->c2)
+        kfree(challenge);
+    return ret;
+}
+
+int nvme_auth_generate_key(struct nvme_ctrl *ctrl)
+{
+    u8 *secret = ctrl->opts->dhchap_secret;
+    u8 *key;
+    size_t key_len;
+    u8 key_hash;
+
+    if (!secret)
+        return 0;
+
+    if (sscanf(secret, "DHHC-1:%hhd:%*s:", &key_hash) != 1)
+        return -EINVAL;
+
+    /* Pass in the secret without the 'DHHC-1:XX:' prefix */
+    key = nvme_auth_extract_secret(secret + 10, key_hash,
+                       &key_len);
+    if (IS_ERR(key)) {
+        dev_dbg(ctrl->device, "failed to extract key, error %ld\n",
+            PTR_ERR(key));
+        return PTR_ERR(key);
+    }
+
+    ctrl->dhchap_key = key;
+    key = NULL;
+    ctrl->dhchap_key_len = key_len;
+    ctrl->dhchap_key_hash = key_hash;
+
+    return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_generate_key);
+
+int nvme_auth_generate_ctrl_key(struct nvme_ctrl *ctrl)
+{
+    u8 *secret = ctrl->opts->dhchap_ctrl_secret;
+    u8 *key;
+    size_t key_len;
+    u8 key_hash;
+
+    if (!secret)
+        return 0;
+
+    if (sscanf(secret, "DHHC-1:%hhd:%*s:", &key_hash) != 1)
+        return -EINVAL;
+
+    /* Pass in the secret without the 'DHHC-1:XX:' prefix */
+    key = nvme_auth_extract_secret(secret + 10, key_hash,
+                       &key_len);
+    if (IS_ERR(key))
+        return PTR_ERR(key);
+
+    ctrl->dhchap_ctrl_key = key;
+    key = NULL;
+    ctrl->dhchap_ctrl_key_len = key_len;
+    ctrl->dhchap_ctrl_key_hash = key_hash;
+    return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_generate_ctrl_key);
This and the other look identical just operate on
a different key, perhaps merge them into one?
Yeah; was too lazy here.
I could easily add a flag to differentiate between host and controller key.
Overall this looks sane to me.
Just nitpicking on the logging to use err when you
hit a errors.
Will be fixing stuff up and send out a new version.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		           Kernel Storage Architect
hare@suse.de			                  +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Felix Imendörffer
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