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authorMimi Zohar <zohar@linux.vnet.ibm.com>2013-06-07 12:16:37 +0200
committerMimi Zohar <zohar@linux.vnet.ibm.com>2013-10-26 21:32:55 -0400
commite7a2ad7eb6f48ad80c70a22dd8167fb34b409466 (patch)
treed1b7e58d2029a273a347b9b9a08f35c50b244d27 /security/integrity
parent9b9d4ce592d283fc4c01da746c02a840c499bb7e (diff)
downloadlinux-stericsson-e7a2ad7eb6f48ad80c70a22dd8167fb34b409466.tar.gz
ima: enable support for larger default filedata hash algorithms
The IMA measurement list contains two hashes - a template data hash and a filedata hash. The template data hash is committed to the TPM, which is limited, by the TPM v1.2 specification, to 20 bytes. The filedata hash is defined as 20 bytes as well. Now that support for variable length measurement list templates was added, the filedata hash is not limited to 20 bytes. This patch adds Kconfig support for defining larger default filedata hash algorithms and replacing the builtin default with one specified on the kernel command line. <uapi/linux/hash_info.h> contains a list of hash algorithms. The Kconfig default hash algorithm is a subset of this list, but any hash algorithm included in the list can be specified at boot, using the 'ima_hash=' kernel command line option. Changelog v2: - update Kconfig Changelog: - support hashes that are configured - use generic HASH_ALGO_ definitions - add Kconfig support - hash_setup must be called only once (Dmitry) - removed trailing whitespaces (Roberto Sassu) Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Diffstat (limited to 'security/integrity')
-rw-r--r--security/integrity/ima/Kconfig35
-rw-r--r--security/integrity/ima/ima_main.c26
2 files changed, 59 insertions, 2 deletions
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index de26cc873ae6..351a58ed56ab 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -71,6 +71,41 @@ config IMA_DEFAULT_TEMPLATE
default "ima" if IMA_TEMPLATE
default "ima-ng" if IMA_NG_TEMPLATE
+choice
+ prompt "Default integrity hash algorithm"
+ default IMA_DEFAULT_HASH_SHA1
+ depends on IMA
+ help
+ Select the default hash algorithm used for the measurement
+ list, integrity appraisal and audit log. The compiled default
+ hash algorithm can be overwritten using the kernel command
+ line 'ima_hash=' option.
+
+ config IMA_DEFAULT_HASH_SHA1
+ bool "SHA1 (default)"
+ depends on CRYPTO_SHA1
+
+ config IMA_DEFAULT_HASH_SHA256
+ bool "SHA256"
+ depends on CRYPTO_SHA256 && !IMA_TEMPLATE
+
+ config IMA_DEFAULT_HASH_SHA512
+ bool "SHA512"
+ depends on CRYPTO_SHA512 && !IMA_TEMPLATE
+
+ config IMA_DEFAULT_HASH_WP512
+ bool "WP512"
+ depends on CRYPTO_WP512 && !IMA_TEMPLATE
+endchoice
+
+config IMA_DEFAULT_HASH
+ string
+ depends on IMA
+ default "sha1" if IMA_DEFAULT_HASH_SHA1
+ default "sha256" if IMA_DEFAULT_HASH_SHA256
+ default "sha512" if IMA_DEFAULT_HASH_SHA512
+ default "wp512" if IMA_DEFAULT_HASH_WP512
+
config IMA_APPRAISE
bool "Appraise integrity measurements"
depends on IMA
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 0b11bb49ac4f..14d4cb557894 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -37,11 +37,32 @@ int ima_appraise;
#endif
int ima_hash_algo = HASH_ALGO_SHA1;
+static int hash_setup_done;
static int __init hash_setup(char *str)
{
- if (strncmp(str, "md5", 3) == 0)
- ima_hash_algo = HASH_ALGO_MD5;
+ struct ima_template_desc *template_desc = ima_template_desc_current();
+ int i;
+
+ if (hash_setup_done)
+ return 1;
+
+ 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)
+ ima_hash_algo = HASH_ALGO_MD5;
+ goto out;
+ }
+
+ for (i = 0; i < HASH_ALGO__LAST; i++) {
+ if (strcmp(str, hash_algo_name[i]) == 0) {
+ ima_hash_algo = i;
+ break;
+ }
+ }
+out:
+ hash_setup_done = 1;
return 1;
}
__setup("ima_hash=", hash_setup);
@@ -306,6 +327,7 @@ static int __init init_ima(void)
{
int error;
+ hash_setup(CONFIG_IMA_DEFAULT_HASH);
error = ima_init();
if (!error)
ima_initialized = 1;