From c019e307ad82a8ee652b8ccbacf69ae94263b07b Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Mon, 3 Feb 2014 13:56:04 +0100 Subject: [PATCH] ima: restore the original behavior for sending data with ima template With the new template mechanism introduced in IMA since kernel 3.13, the format of data sent through the binary_runtime_measurements interface is slightly changed. Now, for a generic measurement, the format of template data (after the template name) is: template_len | field1_len | field1 | ... | fieldN_len | fieldN In addition, fields containing a string now include the '\0' termination character. Instead, the format for the 'ima' template should be: SHA1 digest | event name length | event name It must be noted that while in the IMA 3.13 code 'event name length' is 'IMA_EVENT_NAME_LEN_MAX + 1' (256 bytes), so that the template digest is calculated correctly, and 'event name' contains '\0', in the pre 3.13 code 'event name length' is exactly the string length and 'event name' does not contain the termination character. The patch restores the behavior of the IMA code pre 3.13 for the 'ima' template so that legacy userspace tools obtain a consistent behavior when receiving data from the binary_runtime_measurements interface regardless of which kernel version is used. Signed-off-by: Roberto Sassu Cc: # 3.3.13: 3ce1217 ima: define template fields library Signed-off-by: Mimi Zohar --- security/integrity/ima/ima.h | 2 +- security/integrity/ima/ima_fs.c | 2 ++ security/integrity/ima/ima_template_lib.c | 10 +++++++--- 3 files changed, 10 insertions(+), 4 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 0356e1d..f79fa8b 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -27,7 +27,7 @@ #include "../integrity.h" enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN, - IMA_SHOW_ASCII }; + IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII }; enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 }; /* digest size for IMA, fits SHA1 or MD5 */ diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index db01125..468a3ba 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -160,6 +160,8 @@ static int ima_measurements_show(struct seq_file *m, void *v) if (is_ima_template && strcmp(field->field_id, "d") == 0) show = IMA_SHOW_BINARY_NO_FIELD_LEN; + if (is_ima_template && strcmp(field->field_id, "n") == 0) + show = IMA_SHOW_BINARY_OLD_STRING_FMT; field->field_show(m, show, &e->template_data[i]); } return 0; diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index 1683bbf..e8592e7 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -109,13 +109,16 @@ static void ima_show_template_data_binary(struct seq_file *m, enum data_formats datafmt, struct ima_field_data *field_data) { + u32 len = (show == IMA_SHOW_BINARY_OLD_STRING_FMT) ? + strlen(field_data->data) : field_data->len; + if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) - ima_putc(m, &field_data->len, sizeof(u32)); + ima_putc(m, &len, sizeof(len)); - if (!field_data->len) + if (!len) return; - ima_putc(m, field_data->data, field_data->len); + ima_putc(m, field_data->data, len); } static void ima_show_template_field_data(struct seq_file *m, @@ -129,6 +132,7 @@ static void ima_show_template_field_data(struct seq_file *m, break; case IMA_SHOW_BINARY: case IMA_SHOW_BINARY_NO_FIELD_LEN: + case IMA_SHOW_BINARY_OLD_STRING_FMT: ima_show_template_data_binary(m, show, datafmt, field_data); break; default: -- 1.9.1