Message-Id: <1565682784-10234-6-git-send-email-sumit.garg@linaro.org>
Date:   Tue, 13 Aug 2019 13:23:04 +0530
From:   Sumit Garg <sumit.garg@...aro.org>
To:     keyrings@...r.kernel.org, linux-integrity@...r.kernel.org,
        linux-crypto@...r.kernel.org, linux-security-module@...r.kernel.org
Cc:     dhowells@...hat.com, herbert@...dor.apana.org.au,
        davem@...emloft.net, peterhuewe@....de, jgg@...pe.ca,
        jejb@...ux.ibm.com, jarkko.sakkinen@...ux.intel.com, arnd@...db.de,
        gregkh@...uxfoundation.org, zohar@...ux.ibm.com, jmorris@...ei.org,
        serge@...lyn.com, casey@...aufler-ca.com,
        ard.biesheuvel@...aro.org, daniel.thompson@...aro.org,
        linux-kernel@...r.kernel.org, tee-dev@...ts.linaro.org,
        Sumit Garg <sumit.garg@...aro.org>
Subject: [RFC/RFT v4 5/5] KEYS: trusted: Add generic trusted keys framework

Current trusted keys framework is tightly coupled to use TPM device as
an underlying implementation which makes it difficult for implementations
like Trusted Execution Environment (TEE) etc. to provide trusked keys
support in case platform doesn't posses a TPM device.

So this patch tries to add generic trusted keys framework where underlying
implemtations like TPM, TEE etc. could be easily plugged-in.

Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
Signed-off-by: Sumit Garg <sumit.garg@...aro.org>
---
 include/keys/trusted-type.h                 |  45 ++++
 include/keys/trusted_tpm.h                  |  15 --
 security/keys/trusted-keys/Makefile         |   1 +
 security/keys/trusted-keys/trusted-common.c | 343 +++++++++++++++++++++++++++
 security/keys/trusted-keys/trusted-tpm.c    | 345 +++++-----------------------
 5 files changed, 447 insertions(+), 302 deletions(-)
 create mode 100644 security/keys/trusted-keys/trusted-common.c

diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
index a94c03a..5559010 100644
--- a/include/keys/trusted-type.h
+++ b/include/keys/trusted-type.h
@@ -40,6 +40,51 @@ struct trusted_key_options {
 	uint32_t policyhandle;
 };
 
+struct trusted_key_ops {
+	/*
+	 * flag to indicate if trusted key implementation supports migration
+	 * or not.
+	 */
+	unsigned char migratable;
+
+	/* trusted key init */
+	int (*init)(void);
+
+	/* seal a trusted key */
+	int (*seal)(struct trusted_key_payload *p, char *datablob);
+
+	/* unseal a trusted key */
+	int (*unseal)(struct trusted_key_payload *p, char *datablob);
+
+	/* get random trusted key */
+	int (*get_random)(unsigned char *key, size_t key_len);
+
+	/* trusted key cleanup */
+	void (*cleanup)(void);
+};
+
 extern struct key_type key_type_trusted;
+#if defined(CONFIG_TCG_TPM)
+extern struct trusted_key_ops tpm_trusted_key_ops;
+#endif
+
+#define TRUSTED_DEBUG 0
+
+#if TRUSTED_DEBUG
+static inline void dump_payload(struct trusted_key_payload *p)
+{
+	pr_info("trusted_key: key_len %d\n", p->key_len);
+	print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,
+		       16, 1, p->key, p->key_len, 0);
+	pr_info("trusted_key: bloblen %d\n", p->blob_len);
+	print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,
+		       16, 1, p->blob, p->blob_len, 0);
+	pr_info("trusted_key: migratable %d\n", p->migratable);
+}
+#else
+static inline void dump_payload(struct trusted_key_payload *p)
+{
+}
+#endif
 
 #endif /* _KEYS_TRUSTED_TYPE_H */
diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h
index 0d72106..7b59344 100644
--- a/include/keys/trusted_tpm.h
+++ b/include/keys/trusted_tpm.h
@@ -57,17 +57,6 @@ static inline void dump_options(struct trusted_key_options *o)
 		       16, 1, o->pcrinfo, o->pcrinfo_len, 0);
 }
 
-static inline void dump_payload(struct trusted_key_payload *p)
-{
-	pr_info("trusted_key: key_len %d\n", p->key_len);
-	print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE,
-		       16, 1, p->key, p->key_len, 0);
-	pr_info("trusted_key: bloblen %d\n", p->blob_len);
-	print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE,
-		       16, 1, p->blob, p->blob_len, 0);
-	pr_info("trusted_key: migratable %d\n", p->migratable);
-}
-
 static inline void dump_sess(struct osapsess *s)
 {
 	print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE,
@@ -93,10 +82,6 @@ static inline void dump_options(struct trusted_key_options *o)
 {
 }
 
-static inline void dump_payload(struct trusted_key_payload *p)
-{
-}
-
 static inline void dump_sess(struct osapsess *s)
 {
 }
diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile
index fb42e94..9a4f721 100644
--- a/security/keys/trusted-keys/Makefile
+++ b/security/keys/trusted-keys/Makefile
@@ -4,5 +4,6 @@
 #
 
 obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
+trusted-y += trusted-common.o
 trusted-y += trusted-tpm.o
 trusted-y += trusted-tpm2.o
diff --git a/security/keys/trusted-keys/trusted-common.c b/security/keys/trusted-keys/trusted-common.c
new file mode 100644
index 0000000..8f00fde
--- /dev/null
+++ b/security/keys/trusted-keys/trusted-common.c
@@ -0,0 +1,343 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2010 IBM Corporation
+ * Copyright (c) 2019, Linaro Limited
+ *
+ * Author:
+ * David Safford <safford@...ibm.com>
+ * Added generic trusted key framework: Sumit Garg <sumit.garg@...aro.org>
+ *
+ * See Documentation/security/keys/trusted-encrypted.rst
+ */
+
+#include <keys/user-type.h>
+#include <keys/trusted-type.h>
+#include <linux/capability.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/key-type.h>
+#include <linux/module.h>
+#include <linux/parser.h>
+#include <linux/rcupdate.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+
+static struct trusted_key_ops *available_tk_ops[] = {
+#if defined(CONFIG_TCG_TPM)
+	&tpm_trusted_key_ops,
+#endif
+};
+static struct trusted_key_ops *tk_ops;
+
+enum {
+	Opt_err,
+	Opt_new, Opt_load, Opt_update,
+};
+
+static const match_table_t key_tokens = {
+	{Opt_new, "new"},
+	{Opt_load, "load"},
+	{Opt_update, "update"},
+	{Opt_err, NULL}
+};
+
+/*
+ * datablob_parse - parse the keyctl data and fill in the
+ *                  payload structure
+ *
+ * On success returns 0, otherwise -EINVAL.
+ */
+static int datablob_parse(char *datablob, struct trusted_key_payload *p)
+{
+	substring_t args[MAX_OPT_ARGS];
+	long keylen;
+	int ret = -EINVAL;
+	int key_cmd;
+	char *c;
+
+	/* main command */
+	c = strsep(&datablob, " \t");
+	if (!c)
+		return -EINVAL;
+	key_cmd = match_token(c, key_tokens, args);
+	switch (key_cmd) {
+	case Opt_new:
+		/* first argument is key size */
+		c = strsep(&datablob, " \t");
+		if (!c)
+			return -EINVAL;
+		ret = kstrtol(c, 10, &keylen);
+		if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
+			return -EINVAL;
+		p->key_len = keylen;
+		ret = Opt_new;
+		break;
+	case Opt_load:
+		/* first argument is sealed blob */
+		c = strsep(&datablob, " \t");
+		if (!c)
+			return -EINVAL;
+		p->blob_len = strlen(c) / 2;
+		if (p->blob_len > MAX_BLOB_SIZE)
+			return -EINVAL;
+		ret = hex2bin(p->blob, c, p->blob_len);
+		if (ret < 0)
+			return -EINVAL;
+		ret = Opt_load;
+		break;
+	case Opt_update:
+		ret = Opt_update;
+		break;
+	case Opt_err:
+		return -EINVAL;
+	}
+	return ret;
+}
+
+static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
+{
+	struct trusted_key_payload *p = NULL;
+	int ret;
+
+	ret = key_payload_reserve(key, sizeof(*p));
+	if (ret < 0)
+		return p;
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+
+	p->migratable = tk_ops->migratable;
+
+	return p;
+}
+
+/*
+ * trusted_instantiate - create a new trusted key
+ *
+ * Unseal an existing trusted blob or, for a new key, get a
+ * random key, then seal and create a trusted key-type key,
+ * adding it to the specified keyring.
+ *
+ * On success, return 0. Otherwise return errno.
+ */
+static int trusted_instantiate(struct key *key,
+			       struct key_preparsed_payload *prep)
+{
+	struct trusted_key_payload *payload = NULL;
+	size_t datalen = prep->datalen;
+	char *datablob;
+	int ret = 0;
+	int key_cmd;
+	size_t key_len;
+
+	if (datalen <= 0 || datalen > 32767 || !prep->data)
+		return -EINVAL;
+
+	datablob = kmalloc(datalen + 1, GFP_KERNEL);
+	if (!datablob)
+		return -ENOMEM;
+	memcpy(datablob, prep->data, datalen);
+	datablob[datalen] = '\0';
+
+	payload = trusted_payload_alloc(key);
+	if (!payload) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	key_cmd = datablob_parse(datablob, payload);
+	if (key_cmd < 0) {
+		ret = key_cmd;
+		goto out;
+	}
+
+	dump_payload(payload);
+
+	switch (key_cmd) {
+	case Opt_load:
+		ret = tk_ops->unseal(payload, datablob);
+		dump_payload(payload);
+		if (ret < 0)
+			pr_info("trusted_key: key_unseal failed (%d)\n", ret);
+		break;
+	case Opt_new:
+		key_len = payload->key_len;
+		ret = tk_ops->get_random(payload->key, key_len);
+		if (ret != key_len) {
+			pr_info("trusted_key: key_create failed (%d)\n", ret);
+			goto out;
+		}
+
+		ret = tk_ops->seal(payload, datablob);
+		if (ret < 0)
+			pr_info("trusted_key: key_seal failed (%d)\n", ret);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+out:
+	kzfree(datablob);
+	if (!ret)
+		rcu_assign_keypointer(key, payload);
+	else
+		kzfree(payload);
+	return ret;
+}
+
+static void trusted_rcu_free(struct rcu_head *rcu)
+{
+	struct trusted_key_payload *p;
+
+	p = container_of(rcu, struct trusted_key_payload, rcu);
+	kzfree(p);
+}
+
+/*
+ * trusted_update - reseal an existing key with new PCR values
+ */
+static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
+{
+	struct trusted_key_payload *p;
+	struct trusted_key_payload *new_p;
+	size_t datalen = prep->datalen;
+	char *datablob;
+	int ret = 0;
+
+	if (key_is_negative(key))
+		return -ENOKEY;
+	p = key->payload.data[0];
+	if (!p->migratable)
+		return -EPERM;
+	if (datalen <= 0 || datalen > 32767 || !prep->data)
+		return -EINVAL;
+
+	datablob = kmalloc(datalen + 1, GFP_KERNEL);
+	if (!datablob)
+		return -ENOMEM;
+
+	new_p = trusted_payload_alloc(key);
+	if (!new_p) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	memcpy(datablob, prep->data, datalen);
+	datablob[datalen] = '\0';
+	ret = datablob_parse(datablob, new_p);
+	if (ret != Opt_update) {
+		ret = -EINVAL;
+		kzfree(new_p);
+		goto out;
+	}
+
+	/* copy old key values, and reseal with new pcrs */
+	new_p->migratable = p->migratable;
+	new_p->key_len = p->key_len;
+	memcpy(new_p->key, p->key, p->key_len);
+	dump_payload(p);
+	dump_payload(new_p);
+
+	ret = tk_ops->seal(new_p, datablob);
+	if (ret < 0) {
+		pr_info("trusted_key: key_seal failed (%d)\n", ret);
+		kzfree(new_p);
+		goto out;
+	}
+
+	rcu_assign_keypointer(key, new_p);
+	call_rcu(&p->rcu, trusted_rcu_free);
+out:
+	kzfree(datablob);
+	return ret;
+}
+
+/*
+ * trusted_read - copy the sealed blob data to userspace in hex.
+ * On success, return to userspace the trusted key datablob size.
+ */
+static long trusted_read(const struct key *key, char __user *buffer,
+			 size_t buflen)
+{
+	const struct trusted_key_payload *p;
+	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_array(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;
+}
+
+/*
+ * trusted_destroy - clear and free the key's payload
+ */
+static void trusted_destroy(struct key *key)
+{
+	kzfree(key->payload.data[0]);
+}
+
+struct key_type key_type_trusted = {
+	.name = "trusted",
+	.instantiate = trusted_instantiate,
+	.update = trusted_update,
+	.destroy = trusted_destroy,
+	.describe = user_describe,
+	.read = trusted_read,
+};
+EXPORT_SYMBOL_GPL(key_type_trusted);
+
+static int __init init_trusted(void)
+{
+	int i, ret = 0;
+
+	for (i = 0; i < sizeof(available_tk_ops); i++) {
+		tk_ops = available_tk_ops[i];
+
+		if (!(tk_ops && tk_ops->init && tk_ops->seal &&
+		      tk_ops->unseal && tk_ops->get_random))
+			continue;
+
+		ret = tk_ops->init();
+		if (ret) {
+			if (tk_ops->cleanup)
+				tk_ops->cleanup();
+		} else {
+			break;
+		}
+	}
+
+	/*
+	 * encrypted_keys.ko depends on successful load of this module even if
+	 * trusted key implementation is not found.
+	 */
+	if (ret == -ENODEV)
+		return 0;
+
+	return ret;
+}
+
+static void __exit cleanup_trusted(void)
+{
+	if (tk_ops->cleanup)
+		tk_ops->cleanup();
+}
+
+late_initcall(init_trusted);
+module_exit(cleanup_trusted);
+
+MODULE_LICENSE("GPL");
diff --git a/security/keys/trusted-keys/trusted-tpm.c b/security/keys/trusted-keys/trusted-tpm.c
index 66687e7..dab7c32 100644
--- a/security/keys/trusted-keys/trusted-tpm.c
+++ b/security/keys/trusted-keys/trusted-tpm.c
@@ -1,29 +1,26 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2010 IBM Corporation
+ * Copyright (c) 2019, Linaro Limited
  *
  * Author:
  * David Safford <safford@...ibm.com>
+ * Switch to generic trusted key framework: Sumit Garg <sumit.garg@...aro.org>
  *
  * See Documentation/security/keys/trusted-encrypted.rst
  */
 
 #include <crypto/hash_info.h>
-#include <linux/uaccess.h>
-#include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/parser.h>
 #include <linux/string.h>
 #include <linux/err.h>
-#include <keys/user-type.h>
 #include <keys/trusted-type.h>
 #include <linux/key-type.h>
-#include <linux/rcupdate.h>
 #include <linux/crypto.h>
 #include <crypto/hash.h>
 #include <crypto/sha.h>
-#include <linux/capability.h>
 #include <linux/tpm.h>
 #include <linux/tpm_command.h>
 
@@ -705,7 +702,6 @@ static int key_unseal(struct trusted_key_payload *p,
 
 enum {
 	Opt_err,
-	Opt_new, Opt_load, Opt_update,
 	Opt_keyhandle, Opt_keyauth, Opt_blobauth,
 	Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
 	Opt_hash,
@@ -714,9 +710,6 @@ enum {
 };
 
 static const match_table_t key_tokens = {
-	{Opt_new, "new"},
-	{Opt_load, "load"},
-	{Opt_update, "update"},
 	{Opt_keyhandle, "keyhandle=%s"},
 	{Opt_keyauth, "keyauth=%s"},
 	{Opt_blobauth, "blobauth=%s"},
@@ -843,71 +836,6 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
 	return 0;
 }
 
-/*
- * datablob_parse - parse the keyctl data and fill in the
- * 		    payload and options structures
- *
- * On success returns 0, otherwise -EINVAL.
- */
-static int datablob_parse(char *datablob, struct trusted_key_payload *p,
-			  struct trusted_key_options *o)
-{
-	substring_t args[MAX_OPT_ARGS];
-	long keylen;
-	int ret = -EINVAL;
-	int key_cmd;
-	char *c;
-
-	/* main command */
-	c = strsep(&datablob, " \t");
-	if (!c)
-		return -EINVAL;
-	key_cmd = match_token(c, key_tokens, args);
-	switch (key_cmd) {
-	case Opt_new:
-		/* first argument is key size */
-		c = strsep(&datablob, " \t");
-		if (!c)
-			return -EINVAL;
-		ret = kstrtol(c, 10, &keylen);
-		if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
-			return -EINVAL;
-		p->key_len = keylen;
-		ret = getoptions(datablob, p, o);
-		if (ret < 0)
-			return ret;
-		ret = Opt_new;
-		break;
-	case Opt_load:
-		/* first argument is sealed blob */
-		c = strsep(&datablob, " \t");
-		if (!c)
-			return -EINVAL;
-		p->blob_len = strlen(c) / 2;
-		if (p->blob_len > MAX_BLOB_SIZE)
-			return -EINVAL;
-		ret = hex2bin(p->blob, c, p->blob_len);
-		if (ret < 0)
-			return -EINVAL;
-		ret = getoptions(datablob, p, o);
-		if (ret < 0)
-			return ret;
-		ret = Opt_load;
-		break;
-	case Opt_update:
-		/* all arguments are options */
-		ret = getoptions(datablob, p, o);
-		if (ret < 0)
-			return ret;
-		ret = Opt_update;
-		break;
-	case Opt_err:
-		return -EINVAL;
-		break;
-	}
-	return ret;
-}
-
 static struct trusted_key_options *trusted_options_alloc(void)
 {
 	struct trusted_key_options *options;
@@ -928,258 +856,99 @@ static struct trusted_key_options *trusted_options_alloc(void)
 	return options;
 }
 
-static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
+static int tpm_tk_seal(struct trusted_key_payload *p, char *datablob)
 {
-	struct trusted_key_payload *p = NULL;
-	int ret;
-
-	ret = key_payload_reserve(key, sizeof *p);
-	if (ret < 0)
-		return p;
-	p = kzalloc(sizeof *p, GFP_KERNEL);
-	if (p)
-		p->migratable = 1; /* migratable by default */
-	return p;
-}
-
-/*
- * trusted_instantiate - create a new trusted key
- *
- * Unseal an existing trusted blob or, for a new key, get a
- * random key, then seal and create a trusted key-type key,
- * adding it to the specified keyring.
- *
- * On success, return 0. Otherwise return errno.
- */
-static int trusted_instantiate(struct key *key,
-			       struct key_preparsed_payload *prep)
-{
-	struct trusted_key_payload *payload = NULL;
 	struct trusted_key_options *options = NULL;
-	size_t datalen = prep->datalen;
-	char *datablob;
 	int ret = 0;
-	int key_cmd;
-	size_t key_len;
 	int tpm2;
 
 	tpm2 = tpm_is_tpm2(chip);
 	if (tpm2 < 0)
 		return tpm2;
 
-	if (datalen <= 0 || datalen > 32767 || !prep->data)
-		return -EINVAL;
-
-	datablob = kmalloc(datalen + 1, GFP_KERNEL);
-	if (!datablob)
-		return -ENOMEM;
-	memcpy(datablob, prep->data, datalen);
-	datablob[datalen] = '\0';
-
 	options = trusted_options_alloc();
-	if (!options) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	payload = trusted_payload_alloc(key);
-	if (!payload) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (!options)
+		return -ENOMEM;
 
-	key_cmd = datablob_parse(datablob, payload, options);
-	if (key_cmd < 0) {
-		ret = key_cmd;
+	ret = getoptions(datablob, p, options);
+	if (ret < 0)
 		goto out;
-	}
+	dump_options(options);
 
 	if (!options->keyhandle) {
 		ret = -EINVAL;
 		goto out;
 	}
 
-	dump_payload(payload);
-	dump_options(options);
+	if (tpm2)
+		ret = tpm_seal_trusted(chip, p, options);
+	else
+		ret = key_seal(p, options);
+	if (ret < 0) {
+		pr_info("tpm_trusted_key: key_seal failed (%d)\n", ret);
+		goto out;
+	}
 
-	switch (key_cmd) {
-	case Opt_load:
-		if (tpm2)
-			ret = tpm_unseal_trusted(chip, payload, options);
-		else
-			ret = key_unseal(payload, options);
-		dump_payload(payload);
-		dump_options(options);
-		if (ret < 0)
-			pr_info("trusted_key: key_unseal failed (%d)\n", ret);
-		break;
-	case Opt_new:
-		key_len = payload->key_len;
-		ret = tpm_get_random(chip, payload->key, key_len);
-		if (ret != key_len) {
-			pr_info("trusted_key: key_create failed (%d)\n", ret);
+	if (options->pcrlock) {
+		ret = pcrlock(options->pcrlock);
+		if (ret < 0) {
+			pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret);
 			goto out;
 		}
-		if (tpm2)
-			ret = tpm_seal_trusted(chip, payload, options);
-		else
-			ret = key_seal(payload, options);
-		if (ret < 0)
-			pr_info("trusted_key: key_seal failed (%d)\n", ret);
-		break;
-	default:
-		ret = -EINVAL;
-		goto out;
 	}
-	if (!ret && options->pcrlock)
-		ret = pcrlock(options->pcrlock);
 out:
-	kzfree(datablob);
 	kzfree(options);
-	if (!ret)
-		rcu_assign_keypointer(key, payload);
-	else
-		kzfree(payload);
 	return ret;
 }
 
-static void trusted_rcu_free(struct rcu_head *rcu)
-{
-	struct trusted_key_payload *p;
-
-	p = container_of(rcu, struct trusted_key_payload, rcu);
-	kzfree(p);
-}
-
-/*
- * trusted_update - reseal an existing key with new PCR values
- */
-static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
+static int tpm_tk_unseal(struct trusted_key_payload *p, char *datablob)
 {
-	struct trusted_key_payload *p;
-	struct trusted_key_payload *new_p;
-	struct trusted_key_options *new_o;
-	size_t datalen = prep->datalen;
-	char *datablob;
+	struct trusted_key_options *options = NULL;
 	int ret = 0;
+	int tpm2;
 
-	if (key_is_negative(key))
-		return -ENOKEY;
-	p = key->payload.data[0];
-	if (!p->migratable)
-		return -EPERM;
-	if (datalen <= 0 || datalen > 32767 || !prep->data)
-		return -EINVAL;
+	tpm2 = tpm_is_tpm2(chip);
+	if (tpm2 < 0)
+		return tpm2;
 
-	datablob = kmalloc(datalen + 1, GFP_KERNEL);
-	if (!datablob)
+	options = trusted_options_alloc();
+	if (!options)
 		return -ENOMEM;
-	new_o = trusted_options_alloc();
-	if (!new_o) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	new_p = trusted_payload_alloc(key);
-	if (!new_p) {
-		ret = -ENOMEM;
-		goto out;
-	}
 
-	memcpy(datablob, prep->data, datalen);
-	datablob[datalen] = '\0';
-	ret = datablob_parse(datablob, new_p, new_o);
-	if (ret != Opt_update) {
-		ret = -EINVAL;
-		kzfree(new_p);
+	ret = getoptions(datablob, p, options);
+	if (ret < 0)
 		goto out;
-	}
+	dump_options(options);
 
-	if (!new_o->keyhandle) {
+	if (!options->keyhandle) {
 		ret = -EINVAL;
-		kzfree(new_p);
 		goto out;
 	}
 
-	/* copy old key values, and reseal with new pcrs */
-	new_p->migratable = p->migratable;
-	new_p->key_len = p->key_len;
-	memcpy(new_p->key, p->key, p->key_len);
-	dump_payload(p);
-	dump_payload(new_p);
+	if (tpm2)
+		ret = tpm_unseal_trusted(chip, p, options);
+	else
+		ret = key_unseal(p, options);
+	if (ret < 0)
+		pr_info("tpm_trusted_key: key_unseal failed (%d)\n", ret);
 
-	ret = key_seal(new_p, new_o);
-	if (ret < 0) {
-		pr_info("trusted_key: key_seal failed (%d)\n", ret);
-		kzfree(new_p);
-		goto out;
-	}
-	if (new_o->pcrlock) {
-		ret = pcrlock(new_o->pcrlock);
+	if (options->pcrlock) {
+		ret = pcrlock(options->pcrlock);
 		if (ret < 0) {
-			pr_info("trusted_key: pcrlock failed (%d)\n", ret);
-			kzfree(new_p);
+			pr_info("tpm_trusted_key: pcrlock failed (%d)\n", ret);
 			goto out;
 		}
 	}
-	rcu_assign_keypointer(key, new_p);
-	call_rcu(&p->rcu, trusted_rcu_free);
 out:
-	kzfree(datablob);
-	kzfree(new_o);
+	kzfree(options);
 	return ret;
 }
 
-/*
- * trusted_read - copy the sealed blob data to userspace in hex.
- * On success, return to userspace the trusted key datablob size.
- */
-static long trusted_read(const struct key *key, char __user *buffer,
-			 size_t buflen)
-{
-	const struct trusted_key_payload *p;
-	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_array(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;
-}
-
-/*
- * trusted_destroy - clear and free the key's payload
- */
-static void trusted_destroy(struct key *key)
+int tpm_tk_get_random(unsigned char *key, size_t key_len)
 {
-	kzfree(key->payload.data[0]);
+	return tpm_get_random(chip, key, key_len);
 }
 
-struct key_type key_type_trusted = {
-	.name = "trusted",
-	.instantiate = trusted_instantiate,
-	.update = trusted_update,
-	.destroy = trusted_destroy,
-	.describe = user_describe,
-	.read = trusted_read,
-};
-
-EXPORT_SYMBOL_GPL(key_type_trusted);
-
 static void trusted_shash_release(void)
 {
 	if (hashalg)
@@ -1194,14 +963,14 @@ static int __init trusted_shash_alloc(void)
 
 	hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
 	if (IS_ERR(hmacalg)) {
-		pr_info("trusted_key: could not allocate crypto %s\n",
+		pr_info("tpm_trusted_key: could not allocate crypto %s\n",
 			hmac_alg);
 		return PTR_ERR(hmacalg);
 	}
 
 	hashalg = crypto_alloc_shash(hash_alg, 0, 0);
 	if (IS_ERR(hashalg)) {
-		pr_info("trusted_key: could not allocate crypto %s\n",
+		pr_info("tpm_trusted_key: could not allocate crypto %s\n",
 			hash_alg);
 		ret = PTR_ERR(hashalg);
 		goto hashalg_fail;
@@ -1237,16 +1006,13 @@ static int __init init_digests(void)
 	return 0;
 }
 
-static int __init init_trusted(void)
+static int __init init_tpm_trusted(void)
 {
 	int ret;
 
-	/* encrypted_keys.ko depends on successful load of this module even if
-	 * TPM is not used.
-	 */
 	chip = tpm_default_chip();
 	if (!chip)
-		return 0;
+		return -ENODEV;
 
 	ret = init_digests();
 	if (ret < 0)
@@ -1267,7 +1033,7 @@ static int __init init_trusted(void)
 	return ret;
 }
 
-static void __exit cleanup_trusted(void)
+static void __exit cleanup_tpm_trusted(void)
 {
 	if (chip) {
 		put_device(&chip->dev);
@@ -1277,7 +1043,12 @@ static void __exit cleanup_trusted(void)
 	}
 }
 
-late_initcall(init_trusted);
-module_exit(cleanup_trusted);
-
-MODULE_LICENSE("GPL");
+struct trusted_key_ops tpm_trusted_key_ops = {
+	.migratable = 1, /* migratable by default */
+	.init = init_tpm_trusted,
+	.seal = tpm_tk_seal,
+	.unseal = tpm_tk_unseal,
+	.get_random = tpm_tk_get_random,
+	.cleanup = cleanup_tpm_trusted,
+};
+EXPORT_SYMBOL_GPL(tpm_trusted_key_ops);
-- 
2.7.4

Powered by blists - more mailing lists