ima: do not send field length to userspace for digest of ima template

This patch defines a new value for the 'ima_show_type' enumerator
(IMA_SHOW_BINARY_NO_FIELD_LEN) to prevent that the field length
is transmitted through the 'binary_runtime_measurements' interface
for the digest field of the 'ima' template.

Fixes commit: 3ce1217 ima: define template fields library and new helpers

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This commit is contained in:
Roberto Sassu 2013-11-08 19:21:40 +01:00 коммит произвёл Mimi Zohar
Родитель b6f8f16f41
Коммит 3e8e5503a3
3 изменённых файлов: 18 добавлений и 5 удалений

Просмотреть файл

@ -26,7 +26,8 @@
#include "../integrity.h"
enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII };
enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
IMA_SHOW_ASCII };
enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
/* digest size for IMA, fits SHA1 or MD5 */

Просмотреть файл

@ -120,6 +120,7 @@ static int ima_measurements_show(struct seq_file *m, void *v)
struct ima_template_entry *e;
int namelen;
u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
bool is_ima_template = false;
int i;
/* get entry */
@ -145,14 +146,21 @@ static int ima_measurements_show(struct seq_file *m, void *v)
ima_putc(m, e->template_desc->name, namelen);
/* 5th: template length (except for 'ima' template) */
if (strcmp(e->template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
if (strcmp(e->template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0)
is_ima_template = true;
if (!is_ima_template)
ima_putc(m, &e->template_data_len,
sizeof(e->template_data_len));
/* 6th: template specific data */
for (i = 0; i < e->template_desc->num_fields; i++) {
e->template_desc->fields[i]->field_show(m, IMA_SHOW_BINARY,
&e->template_data[i]);
enum ima_show_type show = IMA_SHOW_BINARY;
struct ima_template_field *field = e->template_desc->fields[i];
if (is_ima_template && strcmp(field->field_id, "d") == 0)
show = IMA_SHOW_BINARY_NO_FIELD_LEN;
field->field_show(m, show, &e->template_data[i]);
}
return 0;
}

Просмотреть файл

@ -109,9 +109,12 @@ static void ima_show_template_data_binary(struct seq_file *m,
enum data_formats datafmt,
struct ima_field_data *field_data)
{
ima_putc(m, &field_data->len, sizeof(u32));
if (show != IMA_SHOW_BINARY_NO_FIELD_LEN)
ima_putc(m, &field_data->len, sizeof(u32));
if (!field_data->len)
return;
ima_putc(m, field_data->data, field_data->len);
}
@ -125,6 +128,7 @@ static void ima_show_template_field_data(struct seq_file *m,
ima_show_template_data_ascii(m, show, datafmt, field_data);
break;
case IMA_SHOW_BINARY:
case IMA_SHOW_BINARY_NO_FIELD_LEN:
ima_show_template_data_binary(m, show, datafmt, field_data);
break;
default: