[PATCH 1/2] security/keys/secure_key: Adds the secure key support based on CAAM.
Udit Agarwal
udit.agarwal at nxp.com
Fri Jul 20 05:46:55 UTC 2018
Secure keys are derieved using CAAM crypto block.
Secure keys derieved are the random number symmetric keys from CAAM.
Blobs corresponding to the key are formed using CAAM. User space
will only be able to view the blob of the key.
Signed-off-by: Udit Agarwal <udit.agarwal at nxp.com>
Reviewed-by: Sahil Malhotra <sahil.malhotra at nxp.com>
---
Documentation/security/keys/secure-key.rst | 67 +++
MAINTAINERS | 11 +
include/keys/secure-type.h | 33 ++
security/keys/Kconfig | 11 +
security/keys/Makefile | 3 +
security/keys/secure_key.c | 339 ++++++++++++
security/keys/securekey_desc.c | 606 +++++++++++++++++++++
security/keys/securekey_desc.h | 141 +++++
8 files changed, 1211 insertions(+)
create mode 100644 Documentation/security/keys/secure-key.rst
create mode 100644 include/keys/secure-type.h
create mode 100644 security/keys/secure_key.c
create mode 100644 security/keys/securekey_desc.c
create mode 100644 security/keys/securekey_desc.h
diff --git a/Documentation/security/keys/secure-key.rst b/Documentation/security/keys/secure-key.rst
new file mode 100644
index 000000000000..0fc3367b00f8
--- /dev/null
+++ b/Documentation/security/keys/secure-key.rst
@@ -0,0 +1,67 @@
+==========
+Secure Key
+==========
+
+Secure key is the new type added to kernel key ring service.
+Secure key is a symmetric type key of minimum length 32 bytes
+and with maximum possible length to be 128 bytes. It is produced
+in kernel using the CAAM crypto engine. Userspace can only see
+the blob for the corresponding key. All the blobs are displayed
+or loaded in hex ascii.
+
+Secure key can only be created on platforms which supports CAAM
+hardware block. Secure key can also be used as a master key to
+create the encrypted keys along with the existing key types in
+kernel.
+
+Secure key uses CAAM hardware to generate the key and blobify its
+content for userspace. Generated blobs are tied up with the hardware
+secret key stored in CAAM, hence the same blob will not be able to
+de-blobify with the different secret key on another machine.
+
+Usage::
+
+ keyctl add secure <name> "new <keylen>" <ring>
+ keyctl load secure <name> "load <hex_blob>" <ring>
+ keyctl print <key_id>
+
+"keyctl add secure" option will create the random data of the
+specified key len using CAAM and store it as a key in kernel.
+Key contents will be displayed as blobs to the user in hex ascii.
+User can input key len from 32 bytes to 128 bytes.
+
+"keyctl load secure" option will load the blob contents. In kernel,
+key will be deirved using input blob and CAAM, along with the secret
+key stored in CAAM.
+
+"keyctl print" will return the hex string of the blob corresponding to
+key_id. Returned blob will be of key_len + 48 bytes. Extra 48 bytes are
+the header bytes added by the CAAM.
+
+Example of secure key usage::
+
+1. Create the secure key with name kmk-master of length 32 bytes::
+
+ $ keyctl add secure kmk-master "new 32" @u
+ 46001928
+
+ $keyctl show
+ Session Keyring
+ 1030783626 --alswrv 0 65534 keyring: _uid_ses.0
+ 695927745 --alswrv 0 65534 \_ keyring: _uid.0
+ 46001928 --als-rv 0 0 \_ secure: kmk-master
+
+2. Print the blob contents for the kmk-master key::
+
+ $ keyctl print 46001928
+ d9743445b640f3d59c1670dddc0bc9c2
+ 34fc9aab7dd05c965e6120025012f029b
+ 07faa4776c4f6ed02899e35a135531e9a
+ 6e5c2b51132f9d5aef28f68738e658296
+ 3fe583177cfe50d2542b659a13039
+
+ $ keyctl pipe 46001928 > secure_key.blob
+
+3. Load the blob in the user key ring::
+
+ $ keyctl load secure kmk-master "load 'cat secure_key.blob'" @u
diff --git a/MAINTAINERS b/MAINTAINERS
index 9fd5e8808208..654be2ee4b0a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7939,6 +7939,17 @@ F: include/keys/trusted-type.h
F: security/keys/trusted.c
F: security/keys/trusted.h
+KEYS-SECURE
+M: Udit Agarwal <udit.agarwal at nxp.com>
+R: Sahil Malhotra <sahil.malhotra at nxp.com>
+L: linux-security-module at vger.kernel.org
+L: keyrings at vger.kernel.org
+S: Supported
+F: include/keys/secure-type.h
+F: security/keys/secure_key.c
+F: security/keys/securekey_desc.c
+F: security/keys/securekey_desc.h
+
KEYS/KEYRINGS:
M: David Howells <dhowells at redhat.com>
L: keyrings at vger.kernel.org
diff --git a/include/keys/secure-type.h b/include/keys/secure-type.h
new file mode 100644
index 000000000000..5b7a5f144e41
--- /dev/null
+++ b/include/keys/secure-type.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 NXP.
+ *
+ */
+
+#ifndef _KEYS_SECURE_TYPE_H
+#define _KEYS_SECURE_TYPE_H
+
+#include <linux/key.h>
+#include <linux/rcupdate.h>
+
+/* Minimum key size to be used is 32 bytes and maximum key size fixed
+ * is 128 bytes.
+ * Blob size to be kept is Maximum key size + blob header added by CAAM.
+ */
+
+#define MIN_KEY_SIZE 32
+#define MAX_KEY_SIZE 128
+#define BLOB_HEADER_SIZE 48
+
+#define MAX_BLOB_SIZE (MAX_KEY_SIZE + BLOB_HEADER_SIZE)
+
+struct secure_key_payload {
+ struct rcu_head rcu;
+ unsigned int key_len;
+ unsigned int blob_len;
+ unsigned char key[MAX_KEY_SIZE + 1];
+ unsigned char blob[MAX_BLOB_SIZE];
+};
+
+extern struct key_type key_type_secure;
+#endif
diff --git a/security/keys/Kconfig b/security/keys/Kconfig
index 6462e6654ccf..7eb138b5a54f 100644
--- a/security/keys/Kconfig
+++ b/security/keys/Kconfig
@@ -71,6 +71,17 @@ config TRUSTED_KEYS
If you are unsure as to whether this is required, answer N.
+config SECURE_KEYS
+ tristate "SECURE_KEYS"
+ depends on KEYS && CRYPTO_DEV_FSL_CAAM && CRYPTO_DEV_FSL_CAAM_JR
+ help
+ This option provide support for creating secure-type key and blobs
+ in kernel. Secure keys are random number symmetric keys generated
+ from CAAM. The CAAM creates the blobs for the random key.
+ Userspace will only be able to see the blob.
+
+ If you are unsure as to whether this is required, answer N.
+
config ENCRYPTED_KEYS
tristate "ENCRYPTED KEYS"
depends on KEYS
diff --git a/security/keys/Makefile b/security/keys/Makefile
index ef1581b337a3..606ba4efb9e6 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -28,4 +28,7 @@ obj-$(CONFIG_KEY_DH_OPERATIONS) += dh.o
#
obj-$(CONFIG_BIG_KEYS) += big_key.o
obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
+ccflags-$(CONFIG_SECURE_KEYS) += -I$(obj)/../../drivers/crypto/caam/
+obj-$(CONFIG_SECURE_KEYS) += securekey_desc.o
+obj-$(CONFIG_SECURE_KEYS) += secure_key.o
obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/
diff --git a/security/keys/secure_key.c b/security/keys/secure_key.c
new file mode 100644
index 000000000000..ec8ad4394549
--- /dev/null
+++ b/security/keys/secure_key.c
@@ -0,0 +1,339 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2018 NXP
+ * Secure key is generated using NXP CAAM hardware block. CAAM generates the
+ * random number (used as a key) and creates its blob for the user.
+ */
+
+#include <linux/slab.h>
+#include <linux/parser.h>
+#include <linux/string.h>
+#include <linux/key-type.h>
+#include <linux/rcupdate.h>
+#include <keys/secure-type.h>
+#include <linux/completion.h>
+
+#include "securekey_desc.h"
+
+static const char hmac_alg[] = "hmac(sha1)";
+static const char hash_alg[] = "sha1";
+
+static struct crypto_shash *hashalg;
+static struct crypto_shash *hmacalg;
+
+enum {
+ error = -1,
+ new_key,
+ load_blob,
+};
+
+static const match_table_t key_tokens = {
+ {new_key, "new"},
+ {load_blob, "load"},
+ {error, NULL}
+};
+
+static struct secure_key_payload *secure_payload_alloc(struct key *key)
+{
+ struct secure_key_payload *sec_key = NULL;
+ int ret = 0;
+
+ ret = key_payload_reserve(key, sizeof(*sec_key));
+ if (ret < 0)
+ goto out;
+
+ sec_key = kzalloc(sizeof(*sec_key), GFP_KERNEL);
+ if (!sec_key)
+ goto out;
+
+out:
+ return sec_key;
+}
+
+/*
+ * parse_inputdata - parse the keyctl input data and fill in the
+ * payload structure for key or its blob.
+ * param[in]: data pointer to the data to be parsed for creating key.
+ * param[in]: p pointer to secure key payload structure to fill parsed data
+ * On success returns 0, otherwise -EINVAL.
+ */
+static int parse_inputdata(char *data, struct secure_key_payload *p)
+{
+ substring_t args[MAX_OPT_ARGS];
+ long keylen = 0;
+ int ret = -EINVAL;
+ int key_cmd = -EINVAL;
+ char *c = NULL;
+
+ c = strsep(&data, " \t");
+ if (!c) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Get the keyctl command i.e. new_key or load_blob etc */
+ key_cmd = match_token(c, key_tokens, args);
+
+ switch (key_cmd) {
+ case new_key:
+ /* first argument is key size */
+ c = strsep(&data, " \t");
+ if (!c) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = kstrtol(c, 10, &keylen);
+ if (ret < 0 || keylen < MIN_KEY_SIZE ||
+ keylen > MAX_KEY_SIZE) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ p->key_len = keylen;
+ ret = new_key;
+
+ break;
+ case load_blob:
+ /* first argument is blob data for CAAM*/
+ c = strsep(&data, " \t");
+ if (!c) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Blob_len = No of characters in blob/2 */
+ p->blob_len = strlen(c) / 2;
+ if (p->blob_len > MAX_BLOB_SIZE) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = hex2bin(p->blob, c, p->blob_len);
+ if (ret < 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = load_blob;
+
+ break;
+ case error:
+ ret = -EINVAL;
+ break;
+ }
+
+out:
+ return ret;
+}
+
+/*
+ * secure_instantiate - create a new secure type key.
+ * Supports the operation to generate a new key. A random number
+ * is generated from CAAM as key data and the corresponding red blob
+ * is formed and stored as key_blob.
+ * Also supports the operation to load the blob and key is derived using
+ * that blob from CAAM.
+ * On success, return 0. Otherwise return errno.
+ */
+static int secure_instantiate(struct key *key,
+ struct key_preparsed_payload *prep)
+{
+ struct secure_key_payload *payload = NULL;
+ size_t datalen = prep->datalen;
+ char *data = NULL;
+ int key_cmd = 0;
+ int ret = 0;
+ enum sk_req_type sk_op_type;
+ struct device *dev = NULL;
+
+ if (datalen <= 0 || datalen > 32767 || !prep->data) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ data = kmalloc(datalen + 1, GFP_KERNEL);
+ if (!data) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ memcpy(data, prep->data, datalen);
+ data[datalen] = '\0';
+
+ payload = secure_payload_alloc(key);
+ if (!payload) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* Allocate caam job ring for operation to be performed from CAAM */
+ dev = caam_jr_alloc();
+ if (!dev) {
+ pr_info("caam_jr_alloc failed\n");
+ ret = -ENODEV;
+ goto out;
+ }
+
+ key_cmd = parse_inputdata(data, payload);
+ if (key_cmd < 0) {
+ ret = key_cmd;
+ goto out;
+ }
+
+ switch (key_cmd) {
+ case load_blob:
+ /*
+ * Red blob decryption to be done for load operation
+ * to derive the key.
+ */
+ sk_op_type = sk_red_blob_dec;
+ ret = key_deblob(payload, sk_op_type, dev);
+ if (ret != 0) {
+ pr_info("secure_key: key_blob decap fail (%d)\n", ret);
+ goto out;
+ }
+ break;
+ case new_key:
+ /* Get Random number from caam of the specified length */
+ sk_op_type = sk_get_random;
+ ret = caam_get_random(payload, sk_op_type, dev);
+ if (ret != 0) {
+ pr_info("secure_key: get_random fail (%d)\n", ret);
+ goto out;
+ }
+
+ /* Generate red blob of key random bytes with CAAM */
+ sk_op_type = sk_red_blob_enc;
+ ret = key_blob(payload, sk_op_type, dev);
+ if (ret != 0) {
+ pr_info("secure_key: key_blob encap fail (%d)\n", ret);
+ goto out;
+ }
+ break;
+ default:
+ ret = -EINVAL;
+ goto out;
+ }
+out:
+ if (data)
+ kzfree(data);
+ if (dev)
+ caam_jr_free(dev);
+
+ if (!ret)
+ rcu_assign_keypointer(key, payload);
+ else
+ kzfree(payload);
+
+ return ret;
+}
+
+/*
+ * secure_read - copy the blob data to userspace in hex.
+ * param[in]: key pointer to key struct
+ * param[in]: buffer pointer to user data for creating key
+ * param[in]: buflen is the length of the buffer
+ * On success, return to userspace the secure key data size.
+ */
+static long secure_read(const struct key *key, char __user *buffer,
+ size_t buflen)
+{
+ const struct secure_key_payload *p = NULL;
+ char *ascii_buf;
+ char *bufp;
+ int i;
+
+ p = dereference_key_locked(key);
+ if (!p)
+ return -EINVAL;
+
+ if (buffer && buflen >= 2 * p->blob_len) {
+ ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
+ if (!ascii_buf)
+ return -ENOMEM;
+
+ bufp = ascii_buf;
+ for (i = 0; i < p->blob_len; i++)
+ bufp = hex_byte_pack(bufp, p->blob[i]);
+ if (copy_to_user(buffer, ascii_buf, 2 * p->blob_len) != 0) {
+ kzfree(ascii_buf);
+ return -EFAULT;
+ }
+ kzfree(ascii_buf);
+ }
+ return 2 * p->blob_len;
+}
+
+/*
+ * secure_destroy - clear and free the key's payload
+ */
+static void secure_destroy(struct key *key)
+{
+ kzfree(key->payload.data[0]);
+}
+
+struct key_type key_type_secure = {
+ .name = "secure",
+ .instantiate = secure_instantiate,
+ .destroy = secure_destroy,
+ .read = secure_read,
+};
+EXPORT_SYMBOL_GPL(key_type_secure);
+
+static void secure_shash_release(void)
+{
+ if (hashalg)
+ crypto_free_shash(hashalg);
+ if (hmacalg)
+ crypto_free_shash(hmacalg);
+}
+
+static int __init secure_shash_alloc(void)
+{
+ int ret;
+
+ hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(hmacalg)) {
+ pr_info("secure_key: could not allocate crypto %s\n",
+ hmac_alg);
+ return PTR_ERR(hmacalg);
+ }
+
+ hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(hashalg)) {
+ pr_info("secure_key: could not allocate crypto %s\n",
+ hash_alg);
+ ret = PTR_ERR(hashalg);
+ goto hashalg_fail;
+ }
+
+ return 0;
+
+hashalg_fail:
+ crypto_free_shash(hmacalg);
+ return ret;
+}
+
+static int __init init_secure_key(void)
+{
+ int ret;
+
+ ret = secure_shash_alloc();
+ if (ret < 0)
+ return ret;
+
+ ret = register_key_type(&key_type_secure);
+ if (ret < 0)
+ secure_shash_release();
+ return ret;
+}
+
+static void __exit cleanup_secure_key(void)
+{
+ secure_shash_release();
+ unregister_key_type(&key_type_secure);
+}
+
+late_initcall(init_secure_key);
+module_exit(cleanup_secure_key);
+
+MODULE_LICENSE("GPL");
diff --git a/security/keys/securekey_desc.c b/security/keys/securekey_desc.c
new file mode 100644
index 000000000000..a4fa811a5753
--- /dev/null
+++ b/security/keys/securekey_desc.c
@@ -0,0 +1,606 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 NXP
+ *
+ */
+
+#include <keys/secure-type.h>
+#include "securekey_desc.h"
+
+/* key modifier for blob encapsulation & decapsulation descriptor */
+u8 key_modifier[] = "SECURE_KEY";
+u32 key_modifier_len = 10;
+
+void caam_sk_rng_desc(struct sk_req *skreq, struct sk_desc *skdesc)
+{
+ struct sk_fetch_rnd_data *fetch_rnd_data = NULL;
+ struct random_desc *rnd_desc = NULL;
+ size_t len = 0;
+ u32 *desc = skreq->hwdesc;
+
+ init_job_desc(desc, 0);
+
+ fetch_rnd_data = &skreq->req_u.sk_fetch_rnd_data;
+ rnd_desc = &skdesc->dma_u.random_descp;
+ len = fetch_rnd_data->key_len;
+
+ /* command 0x82500000 */
+ append_cmd(desc, CMD_OPERATION | OP_TYPE_CLASS1_ALG |
+ OP_ALG_ALGSEL_RNG);
+ /* command 0x60340000 | len */
+ append_cmd(desc, CMD_FIFO_STORE | FIFOST_TYPE_RNGSTORE | len);
+ append_ptr(desc, rnd_desc->rnd_data);
+}
+
+void caam_sk_redblob_encap_desc(struct sk_req *skreq, struct sk_desc *skdesc)
+{
+ struct redblob_encap_desc *red_blob_desc =
+ &skdesc->dma_u.redblob_encapdesc;
+ struct sk_red_blob_encap *red_blob_req =
+ &skreq->req_u.sk_red_blob_encap;
+ u32 *desc = skreq->hwdesc;
+
+ init_job_desc(desc, 0);
+
+ /* Load class 2 key with key modifier. */
+ append_key_as_imm(desc, key_modifier, key_modifier_len,
+ key_modifier_len, CLASS_2 | KEY_DEST_CLASS_REG);
+
+ /* SEQ IN PTR Command. */
+ append_seq_in_ptr(desc, red_blob_desc->in_data, red_blob_req->data_sz,
+ 0);
+
+ /* SEQ OUT PTR Command. */
+ append_seq_out_ptr(desc, red_blob_desc->redblob,
+ red_blob_req->redblob_sz, 0);
+
+ /* RedBlob encapsulation PROTOCOL Command. */
+ append_operation(desc, OP_TYPE_ENCAP_PROTOCOL | OP_PCLID_BLOB);
+}
+
+/* void caam_sk_redblob_decap_desc(struct sk_req *skreq, struct sk_desc *skdesc)
+ * brief CAAM Descriptor creator from redblob to plaindata.
+ * param[in] skreq Pointer to secure key request structure
+ * param[in] skdesc Pointer to secure key descriptor structure
+ */
+void caam_sk_redblob_decap_desc(struct sk_req *skreq, struct sk_desc *skdesc)
+{
+ struct redblob_decap_desc *red_blob_desc =
+ &skdesc->dma_u.redblob_decapdesc;
+ struct sk_red_blob_decap *red_blob_req =
+ &skreq->req_u.sk_red_blob_decap;
+ u32 *desc = skreq->hwdesc;
+
+ init_job_desc(desc, 0);
+
+ /* Load class 2 key with key modifier. */
+ append_key_as_imm(desc, key_modifier, key_modifier_len,
+ key_modifier_len, CLASS_2 | KEY_DEST_CLASS_REG);
+
+ /* SEQ IN PTR Command. */
+ append_seq_in_ptr(desc, red_blob_desc->redblob,
+ red_blob_req->redblob_sz, 0);
+
+ /* SEQ OUT PTR Command. */
+ append_seq_out_ptr(desc, red_blob_desc->out_data,
+ red_blob_req->data_sz, 0);
+
+ /* RedBlob decapsulation PROTOCOL Command. */
+ append_operation(desc, OP_TYPE_DECAP_PROTOCOL | OP_PCLID_BLOB);
+}
+
+/* int caam_sk_get_random_map(struct device *dev, struct sk_req *req,
+ * struct sk_desc *skdesc)
+ * brief DMA map the buffer virtual pointers to physical address.
+ * param[in] dev Pointer to job ring device structure
+ * param[in] req Pointer to secure key request structure
+ * param[in] skdesc Pointer to secure key descriptor structure
+ * return 0 on success, error value otherwise.
+ */
+int caam_sk_get_random_map(struct device *dev, struct sk_req *req,
+ struct sk_desc *skdesc)
+{
+ struct sk_fetch_rnd_data *fetch_rnd_data;
+ struct random_desc *rnd_desc;
+
+ fetch_rnd_data = &req->req_u.sk_fetch_rnd_data;
+ rnd_desc = &skdesc->dma_u.random_descp;
+
+ rnd_desc->rnd_data = dma_map_single(dev, fetch_rnd_data->data,
+ fetch_rnd_data->key_len, DMA_FROM_DEVICE);
+
+ if (dma_mapping_error(dev, rnd_desc->rnd_data)) {
+ dev_err(dev, "Unable to map memory\n");
+ goto sk_random_map_fail;
+ }
+ return 0;
+
+sk_random_map_fail:
+ return -ENOMEM;
+}
+
+/* int caam_sk_redblob_encap_map(struct device *dev, struct sk_req *req,
+ * struct sk_desc *skdesc)
+ * brief DMA map the buffer virtual pointers to physical address.
+ * param[in] dev Pointer to job ring device structure
+ * param[in] req Pointer to secure key request structure
+ * param[in] skdesc Pointer to secure key descriptor structure
+ * return 0 on success, error value otherwise.
+ */
+int caam_sk_redblob_encap_map(struct device *dev, struct sk_req *req,
+ struct sk_desc *skdesc)
+{
+ struct sk_red_blob_encap *red_blob_encap;
+ struct redblob_encap_desc *red_blob_desc;
+
+ red_blob_encap = &req->req_u.sk_red_blob_encap;
+ red_blob_desc = &skdesc->dma_u.redblob_encapdesc;
+
+ red_blob_desc->in_data = dma_map_single(dev, red_blob_encap->data,
+ red_blob_encap->data_sz, DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, red_blob_desc->in_data)) {
+ dev_err(dev, "Unable to map memory\n");
+ goto sk_data_fail;
+ }
+
+ red_blob_desc->redblob = dma_map_single(dev, red_blob_encap->redblob,
+ red_blob_encap->redblob_sz, DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, red_blob_desc->redblob)) {
+ dev_err(dev, "Unable to map memory\n");
+ goto sk_redblob_fail;
+ }
+
+ return 0;
+
+sk_redblob_fail:
+ dma_unmap_single(dev, red_blob_desc->in_data, red_blob_encap->data_sz,
+ DMA_TO_DEVICE);
+sk_data_fail:
+ return -ENOMEM;
+}
+
+/* static int caam_sk_redblob_decap_map(struct device *dev,
+ * struct sk_req *req,
+ * struct sk_desc *skdesc)
+ * brief DMA map the buffer virtual pointers to physical address.
+ * param[in] dev Pointer to job ring device structure
+ * param[in] req Pointer to secure key request structure
+ * param[in] skdesc Pointer to secure key descriptor structure
+ * return 0 on success, error value otherwise.
+ */
+int caam_sk_redblob_decap_map(struct device *dev, struct sk_req *req,
+ struct sk_desc *skdesc)
+{
+ struct sk_red_blob_decap *red_blob_decap;
+ struct redblob_decap_desc *red_blob_desc;
+
+ red_blob_decap = &req->req_u.sk_red_blob_decap;
+ red_blob_desc = &skdesc->dma_u.redblob_decapdesc;
+
+ red_blob_desc->redblob = dma_map_single(dev, red_blob_decap->redblob,
+ red_blob_decap->redblob_sz, DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, red_blob_desc->redblob)) {
+ dev_err(dev, "Unable to map memory\n");
+ goto sk_redblob_fail;
+ }
+
+ red_blob_desc->out_data = dma_map_single(dev, red_blob_decap->data,
+ red_blob_decap->data_sz, DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, red_blob_desc->out_data)) {
+ dev_err(dev, "Unable to map memory\n");
+ goto sk_data_fail;
+ }
+
+ return 0;
+
+sk_data_fail:
+ dma_unmap_single(dev, red_blob_desc->redblob,
+ red_blob_decap->redblob_sz, DMA_TO_DEVICE);
+sk_redblob_fail:
+ return -ENOMEM;
+}
+
+/* @fn void securekey_unmap(struct device *dev,
+ * struct sk_desc *skdesc, struct sk_req *req)
+ * @brief DMA unmap the buffer pointers.
+ * @param[in] dev Pointer to job ring device structure
+ * @param[in] skdesc Pointer to secure key descriptor structure
+ * @param[in] req Pointer to secure key request structure
+ */
+void securekey_unmap(struct device *dev,
+ struct sk_desc *skdesc, struct sk_req *req)
+{
+
+ switch (req->type) {
+ case sk_get_random:
+ {
+ struct sk_fetch_rnd_data *fetch_rnd_data;
+ struct random_desc *rnd_desc;
+
+ fetch_rnd_data = &req->req_u.sk_fetch_rnd_data;
+ rnd_desc = &skdesc->dma_u.random_descp;
+
+ /* Unmap Descriptor buffer pointers. */
+ dma_unmap_single(dev, rnd_desc->rnd_data,
+ fetch_rnd_data->key_len,
+ DMA_FROM_DEVICE);
+ break;
+ }
+ case sk_red_blob_enc:
+ {
+ struct sk_red_blob_encap *red_blob_encap;
+ struct redblob_encap_desc *red_blob_desc;
+
+ red_blob_encap = &req->req_u.sk_red_blob_encap;
+ red_blob_desc = &skdesc->dma_u.redblob_encapdesc;
+
+ /* Unmap Descriptor buffer pointers. */
+ dma_unmap_single(dev, red_blob_desc->in_data,
+ red_blob_encap->data_sz,
+ DMA_TO_DEVICE);
+
+ dma_unmap_single(dev, red_blob_desc->redblob,
+ red_blob_encap->redblob_sz,
+ DMA_FROM_DEVICE);
+
+ break;
+ }
+ case sk_red_blob_dec:
+ {
+ struct sk_red_blob_decap *red_blob_decap;
+ struct redblob_decap_desc *red_blob_desc;
+
+ red_blob_decap = &req->req_u.sk_red_blob_decap;
+ red_blob_desc = &skdesc->dma_u.redblob_decapdesc;
+
+ /* Unmap Descriptor buffer pointers. */
+ dma_unmap_single(dev, red_blob_desc->redblob,
+ red_blob_decap->redblob_sz,
+ DMA_TO_DEVICE);
+
+ dma_unmap_single(dev, red_blob_desc->out_data,
+ red_blob_decap->data_sz,
+ DMA_FROM_DEVICE);
+
+ break;
+ }
+ default:
+ dev_err(dev, "Unable to find request type\n");
+ break;
+ }
+ kfree(skdesc);
+}
+
+/* int caam_securekey_desc_init(struct device *dev, struct sk_req *req)
+ * brief CAAM Descriptor creator for secure key operations.
+ * param[in] dev Pointer to job ring device structure
+ * param[in] req Pointer to secure key request structure
+ * return 0 on success, error value otherwise.
+ */
+int caam_securekey_desc_init(struct device *dev, struct sk_req *req)
+{
+ struct sk_desc *skdesc = NULL;
+ int ret = 0;
+
+ switch (req->type) {
+ case sk_get_random:
+ {
+ skdesc = kmalloc(sizeof(*skdesc), GFP_DMA);
+ if (!skdesc) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ skdesc->req_type = req->type;
+
+ if (caam_sk_get_random_map(dev, req, skdesc)) {
+ dev_err(dev, "caam get_random map fail\n");
+ ret = -ENOMEM;
+ goto out;
+ }
+ caam_sk_rng_desc(req, skdesc);
+ break;
+ }
+ case sk_red_blob_enc:
+ {
+ skdesc = kmalloc(sizeof(*skdesc), GFP_DMA);
+ if (!skdesc) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ skdesc->req_type = req->type;
+
+ if (caam_sk_redblob_encap_map(dev, req, skdesc)) {
+ dev_err(dev, "caam redblob_encap map fail\n");
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* Descriptor function to create redblob from data. */
+ caam_sk_redblob_encap_desc(req, skdesc);
+ break;
+ }
+
+ case sk_red_blob_dec:
+ {
+ skdesc = kmalloc(sizeof(*skdesc), GFP_DMA);
+ if (!skdesc) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ skdesc->req_type = req->type;
+
+ if (caam_sk_redblob_decap_map(dev, req, skdesc)) {
+ dev_err(dev, "caam redblob_decap map fail\n");
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* Descriptor function to decap data from redblob. */
+ caam_sk_redblob_decap_desc(req, skdesc);
+ break;
+ }
+ default:
+ pr_debug("Unknown request type\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ req->desc_pointer = (void *)skdesc;
+
+out:
+ return ret;
+}
+
+/* static void caam_op_done (struct device *dev, u32 *desc, u32 ret,
+ * void *context)
+ * brief callback function to be called when descriptor executed.
+ * param[in] dev Pointer to device structure
+ * param[in] desc descriptor pointer
+ * param[in] ret return status of Job submitted
+ * param[in] context void pointer
+ */
+static void caam_op_done(struct device *dev, u32 *desc, u32 ret,
+ void *context)
+{
+ struct sk_req *req = context;
+
+ if (ret) {
+ dev_err(dev, "caam op done err: %x\n", ret);
+ /* print the error source name. */
+ caam_jr_strstatus(dev, ret);
+ }
+ /* Call securekey_unmap function for unmapping the buffer pointers. */
+ securekey_unmap(dev, req->desc_pointer, req);
+
+ req->ret = ret;
+ complete(&req->comp);
+}
+
+
+/* static int sk_job_submit(struct device *jrdev, struct sk_req *req)
+ * brief Enqueue a Job descriptor to Job ring and wait until SEC returns.
+ * param[in] jrdev Pointer to job ring device structure
+ * param[in] req Pointer to secure key request structure
+ * return 0 on success, error value otherwise.
+ */
+static int sk_job_submit(struct device *jrdev, struct sk_req *req)
+{
+ int ret;
+
+ init_completion(&req->comp);
+
+ /* caam_jr_enqueue function for Enqueue a job descriptor */
+ ret = caam_jr_enqueue(jrdev, req->hwdesc, caam_op_done, req);
+ if (!ret)
+ wait_for_completion_interruptible(&req->comp);
+
+ ret = req->ret;
+ return ret;
+}
+
+/* caam_get_random(struct secure_key_payload *p, enum sk_req_type fetch_rnd,
+ * struct device *dev)
+ * Create the random number of the specified length using CAAM block
+ * param[in]: out pointer to place the random bytes
+ * param[in]: length for the random data bytes.
+ * param[in]: dev Pointer to job ring device structure
+ * If operation is successful return 0, otherwise error.
+ */
+int caam_get_random(struct secure_key_payload *p, enum sk_req_type fetch_rnd,
+ struct device *dev)
+{
+ struct sk_fetch_rnd_data *fetch_rnd_data = NULL;
+ struct sk_req *req = NULL;
+ int ret = 0;
+ void *temp = NULL;
+
+ req = kmalloc(sizeof(struct sk_req), GFP_DMA);
+ if (!req) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ req->type = fetch_rnd;
+ fetch_rnd_data = &(req->req_u.sk_fetch_rnd_data);
+
+ /* initialise with key length */
+ fetch_rnd_data->key_len = p->key_len;
+
+ temp = kmalloc(fetch_rnd_data->key_len, GFP_DMA);
+ if (!temp) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ fetch_rnd_data->data = temp;
+
+ ret = caam_securekey_desc_init(dev, req);
+
+ if (ret) {
+ pr_info("caam_securekey_desc_init failed\n");
+ goto out;
+ }
+
+ ret = sk_job_submit(dev, req);
+ if (!ret) {
+ /*Copy output to key buffer. */
+ memcpy(p->key, fetch_rnd_data->data, p->key_len);
+ } else {
+ ret = -EINVAL;
+ }
+
+out:
+ if (req)
+ kfree(req);
+
+ if (temp)
+ kfree(temp);
+
+ return ret;
+}
+
+/* key_deblob(struct secure_key_payload *p, enum sk_req_type decap_type
+ * struct device *dev)
+ * Deblobify the blob to get the key data and fill in secure key payload struct
+ * param[in] p pointer to the secure key payload
+ * param[in] decap_type operation to be done.
+ * param[in] dev dev Pointer to job ring device structure
+ * If operation is successful return 0, otherwise error.
+ */
+int key_deblob(struct secure_key_payload *p, enum sk_req_type decap_type,
+ struct device *dev)
+{
+ unsigned int blob_len;
+ struct sk_red_blob_decap *d_blob;
+ struct sk_req *req = NULL;
+ int total_sz = 0, *temp = NULL, ret = 0;
+
+ req = kmalloc(sizeof(struct sk_req), GFP_DMA);
+ if (!req) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ d_blob = &(req->req_u.sk_red_blob_decap);
+ blob_len = p->blob_len;
+ req->type = decap_type;
+
+ /*
+ * Red blob size is the blob_len filled in payload struct
+ * Data_sz i.e. key is the blob_len - blob header size
+ */
+
+ d_blob->redblob_sz = blob_len;
+ d_blob->data_sz = blob_len - (SK_BLOB_KEY_SZ + SK_BLOB_MAC_SZ);
+ total_sz = d_blob->data_sz + d_blob->redblob_sz;
+
+ temp = kmalloc(total_sz, GFP_DMA);
+ if (!temp) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ req->mem_pointer = temp;
+ d_blob->redblob = temp;
+ d_blob->data = d_blob->redblob + d_blob->redblob_sz;
+ memcpy(d_blob->redblob, p->blob, blob_len);
+
+ ret = caam_securekey_desc_init(dev, req);
+
+ if (ret) {
+ pr_info("caam_securekey_desc_init: Failed\n");
+ goto out;
+ }
+
+ ret = sk_job_submit(dev, req);
+ if (!ret) {
+ /*Copy output to key buffer. */
+ p->key_len = d_blob->data_sz;
+ memcpy(p->key, d_blob->data, p->key_len);
+ } else {
+ ret = -EINVAL;
+ }
+
+out:
+ if (temp)
+ kfree(temp);
+ if (req)
+ kfree(req);
+ return ret;
+}
+
+/* key_blob(struct secure_key_payload *p, enum sk_req_type encap_type,
+ * struct device *dev)
+ * To blobify the key data to get the blob. This blob can only be seen by
+ * userspace.
+ * param[in] p pointer to the secure key payload
+ * param[in] decap_type operation to be done.
+ * param[in] dev dev Pointer to job ring device structure
+ * If operation is successful return 0, otherwise error.
+ */
+int key_blob(struct secure_key_payload *p, enum sk_req_type encap_type,
+ struct device *dev)
+{
+ unsigned int key_len;
+ struct sk_red_blob_encap *k_blob;
+ struct sk_req *req = NULL;
+ int total_sz = 0, *temp = NULL, ret = 0;
+
+ req = kmalloc(sizeof(struct sk_req), GFP_DMA);
+ if (!req) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ key_len = p->key_len;
+
+ req->type = encap_type;
+ k_blob = &(req->req_u.sk_red_blob_encap);
+
+ /*
+ * Data_sz i.e. key len and the corresponding blob_len is
+ * key_len + BLOB header size.
+ */
+
+ k_blob->data_sz = key_len;
+ k_blob->redblob_sz = key_len + SK_BLOB_KEY_SZ + SK_BLOB_MAC_SZ;
+ total_sz = k_blob->data_sz + k_blob->redblob_sz;
+
+ temp = kmalloc(total_sz, GFP_DMA);
+ if (!temp) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ req->mem_pointer = temp;
+ k_blob->data = temp;
+
+ k_blob->redblob = k_blob->data + k_blob->data_sz;
+ memcpy(k_blob->data, p->key, key_len);
+
+ ret = caam_securekey_desc_init(dev, req);
+
+ if (ret) {
+ pr_info("caam_securekey_desc_init failed\n");
+ goto out;
+ }
+
+ ret = sk_job_submit(dev, req);
+ if (!ret) {
+ /*Copy output to key buffer. */
+ p->blob_len = k_blob->redblob_sz;
+ memcpy(p->blob, k_blob->redblob, p->blob_len);
+ } else {
+ ret = -EINVAL;
+ }
+
+out:
+ if (temp)
+ kfree(req->mem_pointer);
+ if (req)
+ kfree(req);
+ return ret;
+
+}
+
diff --git a/security/keys/securekey_desc.h b/security/keys/securekey_desc.h
new file mode 100644
index 000000000000..0ee26e95b205
--- /dev/null
+++ b/security/keys/securekey_desc.h
@@ -0,0 +1,141 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2018 NXP
+ *
+ */
+#ifndef _SECUREKEY_DESC_H_
+#define _SECUREKEY_DESC_H_
+
+#include "compat.h"
+#include "regs.h"
+#include "intern.h"
+#include "desc.h"
+#include "desc_constr.h"
+#include "jr.h"
+#include "error.h"
+#include "pdb.h"
+
+#define SK_BLOB_KEY_SZ 32 /* Blob key size. */
+#define SK_BLOB_MAC_SZ 16 /* Blob MAC size. */
+
+/*
+ * brief defines different kinds of operations supported by this module.
+ */
+enum sk_req_type {
+ sk_get_random,
+ sk_red_blob_enc,
+ sk_red_blob_dec,
+};
+
+
+/*
+ * struct random_des
+ * param[out] rnd_data output buffer for random data.
+ */
+struct random_desc {
+ dma_addr_t rnd_data;
+};
+
+/* struct redblob_encap_desc
+ * details Structure containing dma address for redblob encapsulation.
+ * param[in] in_data input data to redblob encap descriptor.
+ * param[out] redblob output buffer for redblob.
+ */
+struct redblob_encap_desc {
+ dma_addr_t in_data;
+ dma_addr_t redblob;
+};
+
+/* struct redblob_decap_desc
+ * details Structure containing dma address for redblob decapsulation.
+ * param[in] redblob input buffer to redblob decap descriptor.
+ * param[out] out_data output data from redblob decap descriptor.
+ */
+struct redblob_decap_desc {
+ dma_addr_t redblob;
+ dma_addr_t out_data;
+};
+
+/* struct sk_desc
+ * details Structure for securekey descriptor creation.
+ * param[in] req_type operation supported.
+ * param[in] dma_u union of struct for supported operation.
+ */
+struct sk_desc {
+ u32 req_type;
+ union {
+ struct redblob_encap_desc redblob_encapdesc;
+ struct redblob_decap_desc redblob_decapdesc;
+ struct random_desc random_descp;
+ } dma_u;
+};
+
+/* struct sk_fetch_rnd_data
+ * decriptor structure containing key length.
+ */
+struct sk_fetch_rnd_data {
+ void *data;
+ size_t key_len;
+};
+
+/* struct sk_red_blob_encap
+ * details Structure containing buffer pointers for redblob encapsulation.
+ * param[in] data Input data.
+ * param[in] data_sz size of Input data.
+ * param[out] redblob output buffer for redblob.
+ * param[in] redblob_sz size of redblob.
+ */
+struct sk_red_blob_encap {
+ void *data;
+ uint32_t data_sz;
+ void *redblob;
+ uint32_t redblob_sz;
+};
+
+/* struct sk_red_blob_decap
+ * details Structure containing buffer pointers for redblob decapsulation.
+ * param[in] redblob Input redblob.
+ * param[in] redblob_sz size of redblob.
+ * param[out] data output buffer for data.
+ * param[in] data_sz size of output data.
+ */
+struct sk_red_blob_decap {
+ void *redblob;
+ uint32_t redblob_sz;
+ void *data;
+ uint32_t data_sz;
+};
+
+/* struct sk_req
+ * details Structure for securekey request creation.
+ * param[in] type operation supported.
+ * param[in] req_u union of struct for supported operation.
+ * param[out] ret return status of CAAM operation.
+ * param[in] mem_pointer memory pointer for allocated kernel memory.
+ * param[in] desc_pointer Pointer to securekey descriptor creation structure.
+ * param[in] comp struct completion object.
+ * param[in] hwdesc contains descriptor instructions.
+ */
+struct sk_req {
+ enum sk_req_type type;
+ void *arg;
+ union {
+ struct sk_red_blob_encap sk_red_blob_encap;
+ struct sk_red_blob_decap sk_red_blob_decap;
+ struct sk_fetch_rnd_data sk_fetch_rnd_data;
+ } req_u;
+ int ret;
+ void *mem_pointer;
+ void *desc_pointer;
+ struct completion comp;
+ u32 hwdesc[MAX_CAAM_DESCSIZE];
+};
+
+int caam_get_random(struct secure_key_payload *p, enum sk_req_type fetch_rnd,
+ struct device *dev);
+int key_blob(struct secure_key_payload *p, enum sk_req_type encap_type,
+ struct device *dev);
+int key_deblob(struct secure_key_payload *p, enum sk_req_type decap_type,
+ struct device *dev);
+
+#endif /*_SECUREKEY_DESC_H_*/
--
2.17.1
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
More information about the Linux-security-module-archive
mailing list