[PATCH v2 15/23] ima: define template fields library and new helpers
From: Mimi Zohar
Date: Mon Oct 21 2013 - 18:49:06 EST
From: Roberto Sassu <roberto.sassu@xxxxxxxxx>
This patch defines a library containing two initial template fields,
inode digest (d) and file name (n), the 'ima' template descriptor,
whose format is 'd|n', and two helper functions,
ima_write_template_field_data() and ima_show_template_field_data().
Changelog:
- replace ima_eventname_init() parameter NULL checking with BUG_ON.
(suggested by Mimi)
- include "new template fields for inode digest (d) and file name (n)"
definitions to fix a compiler warning. - Mimi
- unnecessary to prefix static function names with 'ima_'. remove
prefix to resolve Lindent formatting changes. - Mimi
- abbreviated/removed inline comments - Mimi
- always send the template field length - Mimi
Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxx>
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
---
security/integrity/ima/Makefile | 2 +-
security/integrity/ima/ima.h | 5 +
security/integrity/ima/ima_fs.c | 4 +-
security/integrity/ima/ima_template.c | 15 ++-
security/integrity/ima/ima_template_lib.c | 193 ++++++++++++++++++++++++++++++
security/integrity/ima/ima_template_lib.h | 31 +++++
6 files changed, 242 insertions(+), 8 deletions(-)
create mode 100644 security/integrity/ima/ima_template_lib.c
create mode 100644 security/integrity/ima/ima_template_lib.h
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index 7fe4ae3..d79263d 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -6,5 +6,5 @@
obj-$(CONFIG_IMA) += ima.o
ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
- ima_policy.o ima_template.o
+ ima_policy.o ima_template.o ima_template_lib.o
ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index c85718f..e1f081d 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -39,6 +39,9 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
#define IMA_TEMPLATE_FIELD_ID_MAX_LEN 16
#define IMA_TEMPLATE_NUM_FIELDS_MAX 15
+#define IMA_TEMPLATE_IMA_NAME "ima"
+#define IMA_TEMPLATE_IMA_FMT "d|n"
+
/* set during initialization */
extern int ima_initialized;
extern int ima_used_chip;
@@ -105,6 +108,8 @@ int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
void ima_add_violation(struct file *file, const unsigned char *filename,
const char *op, const char *cause);
int ima_init_crypto(void);
+void ima_putc(struct seq_file *m, void *data, int datalen);
+void ima_print_digest(struct seq_file *m, u8 *digest, int size);
int ima_init_template(void);
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index c35cfb5..414862e 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -99,7 +99,7 @@ static void ima_measurements_stop(struct seq_file *m, void *v)
{
}
-static void ima_putc(struct seq_file *m, void *data, int datalen)
+void ima_putc(struct seq_file *m, void *data, int datalen)
{
while (datalen--)
seq_putc(m, *(char *)data++);
@@ -167,7 +167,7 @@ static const struct file_operations ima_measurements_ops = {
.release = seq_release,
};
-static void ima_print_digest(struct seq_file *m, u8 *digest, int size)
+void ima_print_digest(struct seq_file *m, u8 *digest, int size)
{
int i;
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index 7e86783..8100422 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -13,15 +13,20 @@
* Helpers to manage template descriptors.
*/
#include "ima.h"
+#include "ima_template_lib.h"
static struct ima_template_desc defined_templates[] = {
+ {.name = IMA_TEMPLATE_IMA_NAME,.fmt = IMA_TEMPLATE_IMA_FMT},
};
static struct ima_template_field supported_fields[] = {
+ {.field_id = "d",.field_init = ima_eventdigest_init,
+ .field_show = ima_show_template_digest},
+ {.field_id = "n",.field_init = ima_eventname_init,
+ .field_show = ima_show_template_string},
};
-static struct ima_template_field *ima_lookup_template_field(
- const char *field_id)
+static struct ima_template_field *lookup_template_field(const char *field_id)
{
int i;
@@ -32,7 +37,7 @@ static struct ima_template_field *ima_lookup_template_field(
return NULL;
}
-static int ima_template_fmt_size(char *template_fmt)
+static int template_fmt_size(char *template_fmt)
{
char c;
int template_fmt_len = strlen(template_fmt);
@@ -53,7 +58,7 @@ static int template_desc_init_fields(char *template_fmt,
int *num_fields)
{
char *c, *template_fmt_ptr = template_fmt;
- int template_num_fields = ima_template_fmt_size(template_fmt);
+ int template_num_fields = template_fmt_size(template_fmt);
int i, result = 0;
if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX)
@@ -66,7 +71,7 @@ static int template_desc_init_fields(char *template_fmt,
}
for (i = 0; (c = strsep(&template_fmt_ptr, "|")) != NULL &&
i < template_num_fields; i++) {
- struct ima_template_field *f = ima_lookup_template_field(c);
+ struct ima_template_field *f = lookup_template_field(c);
if (!f) {
result = -ENOENT;
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
new file mode 100644
index 0000000..e13fc7c
--- /dev/null
+++ b/security/integrity/ima/ima_template_lib.c
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2013 Politecnico di Torino, Italy
+ * TORSEC group -- http://security.polito.it
+ *
+ * Author: Roberto Sassu <roberto.sassu@xxxxxxxxx>
+ *
+ * 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.
+ *
+ * File: ima_template_lib.c
+ * Library of supported template fields.
+ */
+#include "ima_template_lib.h"
+
+enum data_formats { DATA_FMT_DIGEST = 0, DATA_FMT_EVENT_NAME, DATA_FMT_STRING };
+static int ima_write_template_field_data(const void *data, const u32 datalen,
+ enum data_formats datafmt,
+ struct ima_field_data *field_data)
+{
+ u8 *buf, *buf_ptr;
+ u32 buflen;
+
+ switch (datafmt) {
+ case DATA_FMT_EVENT_NAME:
+ buflen = IMA_EVENT_NAME_LEN_MAX + 1;
+ break;
+ case DATA_FMT_STRING:
+ buflen = datalen + 1;
+ break;
+ default:
+ buflen = datalen;
+ }
+
+ buf = kzalloc(buflen, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ memcpy(buf, data, datalen);
+
+ /*
+ * Replace all space characters with underscore for event names and
+ * strings. This avoid that, during the parsing of a measurements list,
+ * filenames with spaces or that end with the suffix ' (deleted)' are
+ * split into multiple template fields (the space is the delimitator
+ * character for measurements lists in ASCII format).
+ */
+ if (datafmt == DATA_FMT_EVENT_NAME || datafmt == DATA_FMT_STRING) {
+ for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++)
+ if (*buf_ptr == ' ')
+ *buf_ptr = '_';
+ }
+
+ field_data->data = buf;
+ field_data->len = buflen;
+ return 0;
+}
+
+static void ima_show_template_data_ascii(struct seq_file *m,
+ enum ima_show_type show,
+ enum data_formats datafmt,
+ struct ima_field_data *field_data)
+{
+ switch (datafmt) {
+ case DATA_FMT_DIGEST:
+ ima_print_digest(m, field_data->data, field_data->len);
+ break;
+ case DATA_FMT_STRING:
+ seq_printf(m, "%s", field_data->data);
+ break;
+ default:
+ break;
+ }
+}
+
+static void ima_show_template_data_binary(struct seq_file *m,
+ enum ima_show_type show,
+ enum data_formats datafmt,
+ struct ima_field_data *field_data)
+{
+ ima_putc(m, &field_data->len, sizeof(u32));
+ if (!field_data->len)
+ return;
+ ima_putc(m, field_data->data, field_data->len);
+}
+
+static void ima_show_template_field_data(struct seq_file *m,
+ enum ima_show_type show,
+ enum data_formats datafmt,
+ struct ima_field_data *field_data)
+{
+ switch (show) {
+ case IMA_SHOW_ASCII:
+ ima_show_template_data_ascii(m, show, datafmt, field_data);
+ break;
+ case IMA_SHOW_BINARY:
+ ima_show_template_data_binary(m, show, datafmt, field_data);
+ break;
+ default:
+ break;
+ }
+}
+
+void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
+ struct ima_field_data *field_data)
+{
+ ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data);
+}
+
+void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
+ struct ima_field_data *field_data)
+{
+ ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data);
+}
+
+/*
+ * This function writes the digest of an event.
+ */
+int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file,
+ const unsigned char *filename,
+ struct ima_field_data *field_data)
+{
+ struct {
+ struct ima_digest_data hdr;
+ char digest[IMA_MAX_DIGEST_SIZE];
+ } hash;
+ u8 *cur_digest = hash.hdr.digest;
+ u32 cur_digestsize = IMA_DIGEST_SIZE;
+ struct inode *inode;
+ int result;
+
+ memset(&hash, 0, sizeof(hash));
+
+ if (!iint) /* recording a violation. */
+ goto out;
+
+ if (iint->ima_hash->algo == ima_hash_algo) {
+ cur_digest = iint->ima_hash->digest;
+ cur_digestsize = iint->ima_hash->length;
+ goto out;
+ }
+
+ if (!file) /* missing info to re-calculate the digest */
+ return -EINVAL;
+
+ inode = file_inode(file);
+ hash.hdr.algo = ima_hash_algo;
+ result = ima_calc_file_hash(file, &hash.hdr);
+ if (result) {
+ integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
+ filename, "collect_data",
+ "failed", result, 0);
+ return result;
+ }
+out:
+ return ima_write_template_field_data(cur_digest, cur_digestsize,
+ DATA_FMT_DIGEST, field_data);
+}
+
+/*
+ * This function writes the name of an event.
+ */
+int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file,
+ const unsigned char *filename,
+ struct ima_field_data *field_data)
+{
+ const char *cur_filename = NULL;
+ u32 cur_filename_len = 0;
+
+ BUG_ON(filename == NULL && file == NULL);
+
+ if (filename) {
+ cur_filename = filename;
+ cur_filename_len = strlen(filename);
+
+ if (cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)
+ goto out;
+ }
+
+ if (file) {
+ cur_filename = file->f_dentry->d_name.name;
+ cur_filename_len = strlen(cur_filename);
+ } else
+ /*
+ * Truncate filename if the latter is too long and
+ * the file descriptor is not available.
+ */
+ cur_filename_len = IMA_EVENT_NAME_LEN_MAX;
+out:
+ return ima_write_template_field_data(cur_filename, cur_filename_len,
+ DATA_FMT_EVENT_NAME, field_data);
+}
diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h
new file mode 100644
index 0000000..2cecc83
--- /dev/null
+++ b/security/integrity/ima/ima_template_lib.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2013 Politecnico di Torino, Italy
+ * TORSEC group -- http://security.polito.it
+ *
+ * Author: Roberto Sassu <roberto.sassu@xxxxxxxxx>
+ *
+ * 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.
+ *
+ * File: ima_template_lib.h
+ * Header for the library of supported template fields.
+ */
+#ifndef __LINUX_IMA_TEMPLATE_LIB_H
+#define __LINUX_IMA_TEMPLATE_LIB_H
+
+#include <linux/seq_file.h>
+#include "ima.h"
+
+void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
+ struct ima_field_data *field_data);
+void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
+ struct ima_field_data *field_data);
+int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file,
+ const unsigned char *filename,
+ struct ima_field_data *field_data);
+int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file,
+ const unsigned char *filename,
+ struct ima_field_data *field_data);
+#endif /* __LINUX_IMA_TEMPLATE_LIB_H */
--
1.8.1.4
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