evm: provide a function to set the EVM key from the kernel

A crypto HW kernel module can possibly initialize the EVM key from the
kernel __init code to enable EVM before calling the 'init' process.
This patch provides a function evm_set_key() to set the EVM key
directly without using the KEY subsystem.

Changes in v4:
* kernel-doc style for evm_set_key

Changes in v3:
* error reporting moved to evm_set_key
* EVM_INIT_HMAC moved to evm_set_key
* added bitop to prevent key setting race

Changes in v2:
* use size_t for key size instead of signed int
* provide EVM_MAX_KEY_SIZE macro in <linux/evm.h>
* provide EVM_MIN_KEY_SIZE macro in <linux/evm.h>

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This commit is contained in:
Dmitry Kasatkin
2015-10-22 21:26:32 +03:00
committed by Mimi Zohar
parent 26ddabfe96
commit 7626676320
3 changed files with 53 additions and 14 deletions

View File

@@ -14,6 +14,7 @@
struct integrity_iint_cache;
#ifdef CONFIG_EVM
extern int evm_set_key(void *key, size_t keylen);
extern enum integrity_status evm_verifyxattr(struct dentry *dentry,
const char *xattr_name,
void *xattr_value,
@@ -42,6 +43,12 @@ static inline int posix_xattr_acl(const char *xattrname)
}
#endif
#else
static inline int evm_set_key(void *key, size_t keylen)
{
return -EOPNOTSUPP;
}
#ifdef CONFIG_INTEGRITY
static inline enum integrity_status evm_verifyxattr(struct dentry *dentry,
const char *xattr_name,