integrity: IMA as an integrity service provider

IMA provides hardware (TPM) based measurement and attestation for
file measurements. As the Trusted Computing (TPM) model requires,
IMA measures all files before they are accessed in any way (on the
integrity_bprm_check, integrity_path_check and integrity_file_mmap
hooks), and commits the measurements to the TPM. Once added to the
TPM, measurements can not be removed.

In addition, IMA maintains a list of these file measurements, which
can be used to validate the aggregate value stored in the TPM.  The
TPM can sign these measurements, and thus the system can prove, to
itself and to a third party, the system's integrity in a way that
cannot be circumvented by malicious or compromised software.

- alloc ima_template_entry before calling ima_store_template()
- log ima_add_boot_aggregate() failure
- removed unused IMA_TEMPLATE_NAME_LEN
- replaced hard coded string length with #define name

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/ima.h b/include/linux/ima.h
index 4ed1e4d962e..dcc3664feee 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -12,6 +12,15 @@
 #ifndef _LINUX_IMA_H
 #define _LINUX_IMA_H
 
+#ifdef CONFIG_IMA
+extern int ima_bprm_check(struct linux_binprm *bprm);
+extern int ima_inode_alloc(struct inode *inode);
+extern void ima_inode_free(struct inode *inode);
+extern int ima_path_check(struct path *path, int mask);
+extern void ima_file_free(struct file *file);
+extern int ima_file_mmap(struct file *file, unsigned long prot);
+
+#else
 static inline int ima_bprm_check(struct linux_binprm *bprm)
 {
 	return 0;
@@ -41,4 +50,5 @@ static inline int ima_file_mmap(struct file *file, unsigned long prot)
 {
 	return 0;
 }
+#endif /* CONFIG_IMA_H */
 #endif /* _LINUX_IMA_H */