[PATCH v4 9/9] ima: platform-independent hash value
From: Mimi Zohar <hidden>
Date: 2016-09-15 11:27:02
Also in:
kexec, lkml
Subsystem:
extended verification module (evm), integrity measurement architecture (ima), security subsystem, the rest · Maintainers:
Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
From: Andreas Steffen <redacted> For remote attestion it is important for the ima measurement values to be platform-independent. Therefore integer fields to be hashed must be converted to canonical format. Changelog: - Define canonical format as little endian (Mimi) Signed-off-by: Andreas Steffen <redacted> Signed-off-by: Mimi Zohar <redacted> --- security/integrity/ima/ima_crypto.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 38f2ed8..802d5d2 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c@@ -477,11 +477,13 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data, u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 }; u8 *data_to_hash = field_data[i].data; u32 datalen = field_data[i].len; + u32 datalen_to_hash = + !ima_canonical_fmt ? datalen : cpu_to_le32(datalen); if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) { rc = crypto_shash_update(shash, - (const u8 *) &field_data[i].len, - sizeof(field_data[i].len)); + (const u8 *) &datalen_to_hash, + sizeof(datalen_to_hash)); if (rc) break; } else if (strcmp(td->fields[i]->field_id, "n") == 0) {
--
2.1.0