[PATCH v5 01/10] IMA: Added KEYRING_CHECK func in IMA policy to measure keys

Mimi Zohar zohar at linux.ibm.com
Tue Nov 12 17:04:56 UTC 2019


On Mon, 2019-11-11 at 11:32 -0800, Lakshmi Ramasubramanian wrote:
> IMA policy needs to support a func to enable measurement of
> asymmetric keys.
> 
> This patch defines a new IMA policy func namely KEYRING_CHECK to
> measure asymmetric keys.

This new feature measures "keys" based on policy, not "keyrings".
 Please change the name to KEY_CHECK.

> 
> Signed-off-by: Lakshmi Ramasubramanian <nramas at linux.microsoft.com>
> ---
>  Documentation/ABI/testing/ima_policy | 6 ++++++
>  security/integrity/ima/ima.h         | 1 +
>  security/integrity/ima/ima_policy.c  | 4 +++-
>  3 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
> index 29aaedf33246..341df49b5ad1 100644
> --- a/Documentation/ABI/testing/ima_policy
> +++ b/Documentation/ABI/testing/ima_policy
> @@ -30,6 +30,7 @@ Description:
>  				[FIRMWARE_CHECK]
>  				[KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
>  				[KEXEC_CMDLINE]
> +				[KEYRING_CHECK]
>  			mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
>  			       [[^]MAY_EXEC]
>  			fsmagic:= hex value
> @@ -113,3 +114,8 @@ Description:
>  		Example of appraise rule allowing modsig appended signatures:
>  
>  			appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig
> +
> +		Example of measure rule using KEYRING_CHECK to measure
> +		all keys:
> +
> +			measure func=KEYRING_CHECK
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index df4ca482fb53..7f23405b2718 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -193,6 +193,7 @@ static inline unsigned long ima_hash_key(u8 *digest)
>  	hook(KEXEC_INITRAMFS_CHECK)	\
>  	hook(POLICY_CHECK)		\
>  	hook(KEXEC_CMDLINE)		\
> +	hook(KEYRING_CHECK)		\
>  	hook(MAX_CHECK)
>  #define __ima_hook_enumify(ENUM)	ENUM,
>  
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index f19a895ad7cd..9ca32ffaaa9d 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -373,7 +373,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  {
>  	int i;
>  
> -	if (func == KEXEC_CMDLINE) {
> +	if ((func == KEXEC_CMDLINE) || (func == KEYRING_CHECK)) {
>  		if ((rule->flags & IMA_FUNC) && (rule->func == func))
>  			return true;
>  		return false;
> @@ -997,6 +997,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
>  				entry->func = POLICY_CHECK;
>  			else if (strcmp(args[0].from, "KEXEC_CMDLINE") == 0)
>  				entry->func = KEXEC_CMDLINE;
> +			else if (strcmp(args[0].from, "KEYRING_CHECK") == 0)
> +				entry->func = KEYRING_CHECK;
>  			else
>  				result = -EINVAL;
>  			if (!result)






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