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-rw-r--r--include/linux/ima.h6
-rw-r--r--security/integrity/ima/ima_main.c49
2 files changed, 55 insertions, 0 deletions
diff --git a/include/linux/ima.h b/include/linux/ima.h
index f4644c54f648..1659217e9b60 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -23,6 +23,7 @@ extern int ima_read_file(struct file *file, enum kernel_read_file_id id);
extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id);
extern void ima_post_path_mknod(struct dentry *dentry);
+extern int ima_file_hash(struct file *file, char *buf, size_t buf_size);
extern void ima_kexec_cmdline(const void *buf, int size);
#ifdef CONFIG_IMA_KEXEC
@@ -91,6 +92,11 @@ static inline void ima_post_path_mknod(struct dentry *dentry)
return;
}
+static inline int ima_file_hash(struct file *file, char *buf, size_t buf_size)
+{
+ return -EOPNOTSUPP;
+}
+
static inline void ima_kexec_cmdline(const void *buf, int size) {}
#endif /* CONFIG_IMA */
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 2272c3255c7d..9fe949c6a530 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -446,6 +446,55 @@ int ima_file_check(struct file *file, int mask)
EXPORT_SYMBOL_GPL(ima_file_check);
/**
+ * ima_file_hash - return the stored measurement if a file has been hashed and
+ * is in the iint cache.
+ * @file: pointer to the file
+ * @buf: buffer in which to store the hash
+ * @buf_size: length of the buffer
+ *
+ * On success, return the hash algorithm (as defined in the enum hash_algo).
+ * If buf is not NULL, this function also outputs the hash into buf.
+ * If the hash is larger than buf_size, then only buf_size bytes will be copied.
+ * It generally just makes sense to pass a buffer capable of holding the largest
+ * possible hash: IMA_MAX_DIGEST_SIZE.
+ * The file hash returned is based on the entire file, including the appended
+ * signature.
+ *
+ * If IMA is disabled or if no measurement is available, return -EOPNOTSUPP.
+ * If the parameters are incorrect, return -EINVAL.
+ */
+int ima_file_hash(struct file *file, char *buf, size_t buf_size)
+{
+ struct inode *inode;
+ struct integrity_iint_cache *iint;
+ int hash_algo;
+
+ if (!file)
+ return -EINVAL;
+
+ if (!ima_policy_flag)
+ return -EOPNOTSUPP;
+
+ inode = file_inode(file);
+ iint = integrity_iint_find(inode);
+ if (!iint)
+ return -EOPNOTSUPP;
+
+ mutex_lock(&iint->mutex);
+ if (buf) {
+ size_t copied_size;
+
+ copied_size = min_t(size_t, iint->ima_hash->length, buf_size);
+ memcpy(buf, iint->ima_hash->digest, copied_size);
+ }
+ hash_algo = iint->ima_hash->algo;
+ mutex_unlock(&iint->mutex);
+
+ return hash_algo;
+}
+EXPORT_SYMBOL_GPL(ima_file_hash);
+
+/**
* ima_post_create_tmpfile - mark newly created tmpfile as new
* @file : newly created tmpfile
*