[PATCH v6 1/5] IMA: remove the dependency on CRYPTO_MD5

THOBY Simon
2021-08-04T09:20:24Z

MD5 is a weak digest algorithm that shouldn't be used for cryptographic
operation. It hinders the efficiency of a patch set that aims to limit
the digests allowed for the extended file attribute namely security.ima.
MD5 is no longer a requirement for IMA, nor should it be used there.

Remove the CRYPTO_MD5 dependency for IMA.

Signed-off-by: Simon Thoby <simon.thoby@viveris.fr>
---
security/integrity/ima/Kconfig | 1 -
security/integrity/ima/ima_main.c | 3 ++-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index d0ceada99243..f3a9cc201c8c 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -6,7 +6,6 @@ config IMA
select SECURITYFS
select CRYPTO
select CRYPTO_HMAC
- select CRYPTO_MD5
select CRYPTO_SHA1
select CRYPTO_HASH_INFO
select TCG_TPM if HAS_IOMEM && !UML
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 1cba6beb5a60..b70ee0125168 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -53,7 +53,8 @@ static int __init hash_setup(char *str)
if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) {
if (strncmp(str, "sha1", 4) == 0) {
ima_hash_algo = HASH_ALGO_SHA1;
- } else if (strncmp(str, "md5", 3) == 0) {
+ } else if (IS_ENABLED(CONFIG_CRYPTO_MD5)
+ && strncmp(str, "md5", 3) == 0) {
ima_hash_algo = HASH_ALGO_MD5;
} else {
pr_err("invalid hash algorithm \"%s\" for template \"%s\"",
--
2.31.1