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-rw-r--r--security/integrity/Kconfig14
-rw-r--r--security/integrity/Makefile1
-rw-r--r--security/integrity/digsig.c48
-rw-r--r--security/integrity/evm/evm.h12
-rw-r--r--security/integrity/evm/evm_crypto.c76
-rw-r--r--security/integrity/evm/evm_main.c94
-rw-r--r--security/integrity/ima/ima_api.c4
-rw-r--r--security/integrity/ima/ima_queue.c17
-rw-r--r--security/integrity/integrity.h21
9 files changed, 244 insertions, 43 deletions
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 4bf00acf7937..d384ea921482 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -3,5 +3,19 @@ config INTEGRITY
def_bool y
depends on IMA || EVM
+config INTEGRITY_DIGSIG
+ boolean "Digital signature verification using multiple keyrings"
+ depends on INTEGRITY && KEYS
+ default n
+ select DIGSIG
+ help
+ This option enables digital signature verification support
+ using multiple keyrings. It defines separate keyrings for each
+ of the different use cases - evm, ima, and modules.
+ Different keyrings improves search performance, but also allow
+ to "lock" certain keyring to prevent adding new keys.
+ This is useful for evm and module keyrings, when keys are
+ usually only added from initramfs.
+
source security/integrity/ima/Kconfig
source security/integrity/evm/Kconfig
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
index 0ae44aea6516..bece0563ee5e 100644
--- a/security/integrity/Makefile
+++ b/security/integrity/Makefile
@@ -3,6 +3,7 @@
#
obj-$(CONFIG_INTEGRITY) += integrity.o
+obj-$(CONFIG_INTEGRITY_DIGSIG) += digsig.o
integrity-y := iint.o
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
new file mode 100644
index 000000000000..2dc167d7cde9
--- /dev/null
+++ b/security/integrity/digsig.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2011 Intel Corporation
+ *
+ * Author:
+ * Dmitry Kasatkin <dmitry.kasatkin@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/rbtree.h>
+#include <linux/key-type.h>
+#include <linux/digsig.h>
+
+#include "integrity.h"
+
+static struct key *keyring[INTEGRITY_KEYRING_MAX];
+
+static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
+ "_evm",
+ "_module",
+ "_ima",
+};
+
+int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
+ const char *digest, int digestlen)
+{
+ if (id >= INTEGRITY_KEYRING_MAX)
+ return -EINVAL;
+
+ if (!keyring[id]) {
+ keyring[id] =
+ request_key(&key_type_keyring, keyring_name[id], NULL);
+ if (IS_ERR(keyring[id])) {
+ int err = PTR_ERR(keyring[id]);
+ pr_err("no %s keyring: %d\n", keyring_name[id], err);
+ keyring[id] = NULL;
+ return err;
+ }
+ }
+
+ return digsig_verify(keyring[id], sig, siglen, digest, digestlen);
+}
diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h
index d320f5197437..c885247ebcf7 100644
--- a/security/integrity/evm/evm.h
+++ b/security/integrity/evm/evm.h
@@ -12,14 +12,21 @@
* File: evm.h
*
*/
+
+#ifndef __INTEGRITY_EVM_H
+#define __INTEGRITY_EVM_H
+
#include <linux/xattr.h>
#include <linux/security.h>
+
#include "../integrity.h"
extern int evm_initialized;
extern char *evm_hmac;
+extern char *evm_hash;
extern struct crypto_shash *hmac_tfm;
+extern struct crypto_shash *hash_tfm;
/* List of EVM protected security xattrs */
extern char *evm_config_xattrnames[];
@@ -32,7 +39,12 @@ extern int evm_update_evmxattr(struct dentry *dentry,
extern int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value,
size_t req_xattr_value_len, char *digest);
+extern int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
+ const char *req_xattr_value,
+ size_t req_xattr_value_len, char *digest);
extern int evm_init_hmac(struct inode *inode, const struct xattr *xattr,
char *hmac_val);
extern int evm_init_secfs(void);
extern void evm_cleanup_secfs(void);
+
+#endif
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index 8738deff26fa..49a464f5595b 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -26,44 +26,56 @@ static unsigned char evmkey[MAX_KEY_SIZE];
static int evmkey_len = MAX_KEY_SIZE;
struct crypto_shash *hmac_tfm;
+struct crypto_shash *hash_tfm;
static DEFINE_MUTEX(mutex);
-static struct shash_desc *init_desc(void)
+static struct shash_desc *init_desc(char type)
{
- int rc;
+ long rc;
+ char *algo;
+ struct crypto_shash **tfm;
struct shash_desc *desc;
- if (hmac_tfm == NULL) {
+ if (type == EVM_XATTR_HMAC) {
+ tfm = &hmac_tfm;
+ algo = evm_hmac;
+ } else {
+ tfm = &hash_tfm;
+ algo = evm_hash;
+ }
+
+ if (*tfm == NULL) {
mutex_lock(&mutex);
- if (hmac_tfm)
+ if (*tfm)
goto out;
- hmac_tfm = crypto_alloc_shash(evm_hmac, 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(hmac_tfm)) {
- pr_err("Can not allocate %s (reason: %ld)\n",
- evm_hmac, PTR_ERR(hmac_tfm));
- rc = PTR_ERR(hmac_tfm);
- hmac_tfm = NULL;
+ *tfm = crypto_alloc_shash(algo, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(*tfm)) {
+ rc = PTR_ERR(*tfm);
+ pr_err("Can not allocate %s (reason: %ld)\n", algo, rc);
+ *tfm = NULL;
mutex_unlock(&mutex);
return ERR_PTR(rc);
}
- rc = crypto_shash_setkey(hmac_tfm, evmkey, evmkey_len);
- if (rc) {
- crypto_free_shash(hmac_tfm);
- hmac_tfm = NULL;
- mutex_unlock(&mutex);
- return ERR_PTR(rc);
+ if (type == EVM_XATTR_HMAC) {
+ rc = crypto_shash_setkey(*tfm, evmkey, evmkey_len);
+ if (rc) {
+ crypto_free_shash(*tfm);
+ *tfm = NULL;
+ mutex_unlock(&mutex);
+ return ERR_PTR(rc);
+ }
}
out:
mutex_unlock(&mutex);
}
- desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac_tfm),
+ desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(*tfm),
GFP_KERNEL);
if (!desc)
return ERR_PTR(-ENOMEM);
- desc->tfm = hmac_tfm;
+ desc->tfm = *tfm;
desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
rc = crypto_shash_init(desc);
@@ -108,9 +120,11 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
* the hmac using the requested xattr value. Don't alloc/free memory for
* each xattr, but attempt to re-use the previously allocated memory.
*/
-int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
- const char *req_xattr_value, size_t req_xattr_value_len,
- char *digest)
+static int evm_calc_hmac_or_hash(struct dentry *dentry,
+ const char *req_xattr_name,
+ const char *req_xattr_value,
+ size_t req_xattr_value_len,
+ char type, char *digest)
{
struct inode *inode = dentry->d_inode;
struct shash_desc *desc;
@@ -122,7 +136,7 @@ int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
if (!inode->i_op || !inode->i_op->getxattr)
return -EOPNOTSUPP;
- desc = init_desc();
+ desc = init_desc(type);
if (IS_ERR(desc))
return PTR_ERR(desc);
@@ -156,6 +170,22 @@ out:
return error;
}
+int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
+ const char *req_xattr_value, size_t req_xattr_value_len,
+ char *digest)
+{
+ return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
+ req_xattr_value_len, EVM_XATTR_HMAC, digest);
+}
+
+int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
+ const char *req_xattr_value, size_t req_xattr_value_len,
+ char *digest)
+{
+ return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
+ req_xattr_value_len, IMA_XATTR_DIGEST, digest);
+}
+
/*
* Calculate the hmac and update security.evm xattr
*
@@ -186,7 +216,7 @@ int evm_init_hmac(struct inode *inode, const struct xattr *lsm_xattr,
{
struct shash_desc *desc;
- desc = init_desc();
+ desc = init_desc(EVM_XATTR_HMAC);
if (IS_ERR(desc)) {
printk(KERN_INFO "init_desc failed\n");
return PTR_ERR(desc);
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 92d3d99a9f7b..8901501425f4 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -25,6 +25,7 @@
int evm_initialized;
char *evm_hmac = "hmac(sha1)";
+char *evm_hash = "sha1";
char *evm_config_xattrnames[] = {
#ifdef CONFIG_SECURITY_SELINUX
@@ -46,6 +47,29 @@ static int __init evm_set_fixmode(char *str)
}
__setup("evm=", evm_set_fixmode);
+static int evm_find_protected_xattrs(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ char **xattr;
+ int error;
+ int count = 0;
+
+ if (!inode->i_op || !inode->i_op->getxattr)
+ return -EOPNOTSUPP;
+
+ for (xattr = evm_config_xattrnames; *xattr != NULL; xattr++) {
+ error = inode->i_op->getxattr(dentry, *xattr, NULL, 0);
+ if (error < 0) {
+ if (error == -ENODATA)
+ continue;
+ return error;
+ }
+ count++;
+ }
+
+ return count;
+}
+
/*
* evm_verify_hmac - calculate and compare the HMAC with the EVM xattr
*
@@ -65,32 +89,72 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
size_t xattr_value_len,
struct integrity_iint_cache *iint)
{
- struct evm_ima_xattr_data xattr_data;
+ struct evm_ima_xattr_data *xattr_data = NULL;
+ struct evm_ima_xattr_data calc;
enum integrity_status evm_status = INTEGRITY_PASS;
- int rc;
+ int rc, xattr_len;
if (iint && iint->evm_status == INTEGRITY_PASS)
return iint->evm_status;
/* if status is not PASS, try to check again - against -ENOMEM */
- rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
- xattr_value_len, xattr_data.digest);
- if (rc < 0) {
- evm_status = (rc == -ENODATA)
- ? INTEGRITY_NOXATTRS : INTEGRITY_FAIL;
+ /* first need to know the sig type */
+ rc = vfs_getxattr_alloc(dentry, XATTR_NAME_EVM, (char **)&xattr_data, 0,
+ GFP_NOFS);
+ if (rc <= 0) {
+ if (rc == 0)
+ evm_status = INTEGRITY_FAIL; /* empty */
+ else if (rc == -ENODATA) {
+ rc = evm_find_protected_xattrs(dentry);
+ if (rc > 0)
+ evm_status = INTEGRITY_NOLABEL;
+ else if (rc == 0)
+ evm_status = INTEGRITY_NOXATTRS; /* new file */
+ }
goto out;
}
- xattr_data.type = EVM_XATTR_HMAC;
- rc = vfs_xattr_cmp(dentry, XATTR_NAME_EVM, (u8 *)&xattr_data,
- sizeof xattr_data, GFP_NOFS);
- if (rc < 0)
- evm_status = (rc == -ENODATA)
- ? INTEGRITY_NOLABEL : INTEGRITY_FAIL;
+ xattr_len = rc - 1;
+
+ /* check value type */
+ switch (xattr_data->type) {
+ case EVM_XATTR_HMAC:
+ rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
+ xattr_value_len, calc.digest);
+ if (rc)
+ break;
+ rc = memcmp(xattr_data->digest, calc.digest,
+ sizeof(calc.digest));
+ if (rc)
+ rc = -EINVAL;
+ break;
+ case EVM_IMA_XATTR_DIGSIG:
+ rc = evm_calc_hash(dentry, xattr_name, xattr_value,
+ xattr_value_len, calc.digest);
+ if (rc)
+ break;
+ rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM,
+ xattr_data->digest, xattr_len,
+ calc.digest, sizeof(calc.digest));
+ if (!rc) {
+ /* we probably want to replace rsa with hmac here */
+ evm_update_evmxattr(dentry, xattr_name, xattr_value,
+ xattr_value_len);
+ }
+ break;
+ default:
+ rc = -EINVAL;
+ break;
+ }
+
+ if (rc)
+ evm_status = (rc == -ENODATA) ?
+ INTEGRITY_NOXATTRS : INTEGRITY_FAIL;
out:
if (iint)
iint->evm_status = evm_status;
+ kfree(xattr_data);
return evm_status;
}
@@ -354,6 +418,8 @@ static int __init init_evm(void)
printk(KERN_INFO "EVM: Error registering secfs\n");
goto err;
}
+
+ return 0;
err:
return error;
}
@@ -363,6 +429,8 @@ static void __exit cleanup_evm(void)
evm_cleanup_secfs();
if (hmac_tfm)
crypto_free_shash(hmac_tfm);
+ if (hash_tfm)
+ crypto_free_shash(hash_tfm);
}
/*
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 0d50df04ccc4..88a2788b981d 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -178,8 +178,8 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
strncpy(entry->template.file_name, filename, IMA_EVENT_NAME_LEN_MAX);
result = ima_store_template(entry, violation, inode);
- if (!result)
+ if (!result || result == -EEXIST)
iint->flags |= IMA_MEASURED;
- else
+ if (result < 0)
kfree(entry);
}
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index 8e28f04a5e2e..55a6271bce7a 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -23,6 +23,8 @@
#include <linux/slab.h>
#include "ima.h"
+#define AUDIT_CAUSE_LEN_MAX 32
+
LIST_HEAD(ima_measurements); /* list of all measurements */
/* key: inode (before secure-hashing a file) */
@@ -94,7 +96,8 @@ static int ima_pcr_extend(const u8 *hash)
result = tpm_pcr_extend(TPM_ANY_NUM, CONFIG_IMA_MEASURE_PCR_IDX, hash);
if (result != 0)
- pr_err("IMA: Error Communicating to TPM chip\n");
+ pr_err("IMA: Error Communicating to TPM chip, result: %d\n",
+ result);
return result;
}
@@ -106,14 +109,16 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,
{
u8 digest[IMA_DIGEST_SIZE];
const char *audit_cause = "hash_added";
+ char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX];
int audit_info = 1;
- int result = 0;
+ int result = 0, tpmresult = 0;
mutex_lock(&ima_extend_list_mutex);
if (!violation) {
memcpy(digest, entry->digest, sizeof digest);
if (ima_lookup_digest_entry(digest)) {
audit_cause = "hash_exists";
+ result = -EEXIST;
goto out;
}
}
@@ -128,9 +133,11 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,
if (violation) /* invalidate pcr */
memset(digest, 0xff, sizeof digest);
- result = ima_pcr_extend(digest);
- if (result != 0) {
- audit_cause = "TPM error";
+ tpmresult = ima_pcr_extend(digest);
+ if (tpmresult != 0) {
+ snprintf(tpm_audit_cause, AUDIT_CAUSE_LEN_MAX, "TPM_error(%d)",
+ tpmresult);
+ audit_cause = tpm_audit_cause;
audit_info = 0;
}
out:
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 3143a3c39868..4da6ba81d153 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -46,5 +46,26 @@ struct integrity_iint_cache {
struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
+#define INTEGRITY_KEYRING_EVM 0
+#define INTEGRITY_KEYRING_MODULE 1
+#define INTEGRITY_KEYRING_IMA 2
+#define INTEGRITY_KEYRING_MAX 3
+
+#ifdef CONFIG_INTEGRITY_DIGSIG
+
+int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
+ const char *digest, int digestlen);
+
+#else
+
+static inline int integrity_digsig_verify(const unsigned int id,
+ const char *sig, int siglen,
+ const char *digest, int digestlen)
+{
+ return -EOPNOTSUPP;
+}
+
+#endif /* CONFIG_INTEGRITY_DIGSIG */
+
/* set during initialization */
extern int iint_initialized;