[PATCH] ima-evm-utils: libimaevm: get key description out of verbose condition

[PATCH] ima-evm-utils: libimaevm: get key description out of verbose condition

[Bruno E. O. Meneguele]

Key description in keyring is being filled with memory garbage during import
process if the LOG_LEVEL is not satisfied (using '-vv').

Testing in kernels without trusted keyring support, and importing a v1 (RSA) key
pair, the kernel fails to find the key since it looks for the key description,
which is not found due to this issue:

    "digsig: key not found, id: DD0558FEB7DDBD26"

Looking at:
    # keyctl show
    Session Keyring
     635748007 --alswrv      0     0  keyring: _ses
     673181018 --alswrv      0 65534   \_ keyring: _uid.0
     360651479 --alswrv      0     0       \_ keyring: _ima
     499360916 --alswrv      0     0       |   \_ user: .N=
     266933436 --alswrv      0     0       |   \_ user: B641632DA94DEE26

Key id 499360916 and 266933436 are both the same key, but the first was added
without '-vv' in the command line, while the second one was using it.

Signed-off-by: Bruno E. O. Meneguele <bmeneg@redhat.com>
---
 src/libimaevm.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/libimaevm.c b/src/libimaevm.c
index 6fa0ed4..b6f9b9f 100644
--- a/src/libimaevm.c
+++ b/src/libimaevm.c
@@ -672,12 +672,11 @@ void calc_keyid_v1(uint8_t *keyid, char *str, const unsigned char *pkey, int len
 	memcpy(keyid, sha1 + 12, 8);
 	log_debug("keyid: ");
 	log_debug_dump(keyid, 8);
+	id = __be64_to_cpup((__be64 *) keyid);
+	sprintf(str, "%llX", (unsigned long long)id);
 
-	if (params.verbose > LOG_INFO) {
-		id = __be64_to_cpup((__be64 *) keyid);
-		sprintf(str, "%llX", (unsigned long long)id);
+	if (params.verbose > LOG_INFO)
 		log_info("keyid-v1: %s\n", str);
-	}
 }
 
 void calc_keyid_v2(uint32_t *keyid, char *str, RSA *key)
@@ -694,11 +693,10 @@ void calc_keyid_v2(uint32_t *keyid, char *str, RSA *key)
 	memcpy(keyid, sha1 + 16, 4);
 	log_debug("keyid: ");
 	log_debug_dump(keyid, 4);
+	sprintf(str, "%x", __be32_to_cpup(keyid));
 
-	if (params.verbose > LOG_INFO) {
-		sprintf(str, "%x", __be32_to_cpup(keyid));
+	if (params.verbose > LOG_INFO)
 		log_info("keyid: %s\n", str);
-	}
 
 	free(pkey);
 }
-- 
2.19.1

Re: [PATCH] ima-evm-utils: libimaevm: get key description out of verbose condition

[Mimi Zohar]

On Fri, 2018-11-30 at 18:05 -0200, Bruno E. O. Meneguele wrote:
> Key description in keyring is being filled with memory garbage during import
> process if the LOG_LEVEL is not satisfied (using '-vv').
> 
> Testing in kernels without trusted keyring support, and importing a v1 (RSA) key
> pair, the kernel fails to find the key since it looks for the key description,
> which is not found due to this issue:
> 
>     "digsig: key not found, id: DD0558FEB7DDBD26"
> 
> Looking at:
>     # keyctl show
>     Session Keyring
>      635748007 --alswrv      0     0  keyring: _ses
>      673181018 --alswrv      0 65534   \_ keyring: _uid.0
>      360651479 --alswrv      0     0       \_ keyring: _ima
>      499360916 --alswrv      0     0       |   \_ user: .N=
>      266933436 --alswrv      0     0       |   \_ user: B641632DA94DEE26
> 
> Key id 499360916 and 266933436 are both the same key, but the first was added
> without '-vv' in the command line, while the second one was using it.
> 
> Signed-off-by: Bruno E. O. Meneguele <bmeneg@redhat.com>

Thanks!

Mimi

> ---
>  src/libimaevm.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/src/libimaevm.c b/src/libimaevm.c
> index 6fa0ed4..b6f9b9f 100644
> --- a/src/libimaevm.c
> +++ b/src/libimaevm.c
> @@ -672,12 +672,11 @@ void calc_keyid_v1(uint8_t *keyid, char *str, const unsigned char *pkey, int len
>  	memcpy(keyid, sha1 + 12, 8);
>  	log_debug("keyid: ");
>  	log_debug_dump(keyid, 8);
> +	id = __be64_to_cpup((__be64 *) keyid);
> +	sprintf(str, "%llX", (unsigned long long)id);
> 
> -	if (params.verbose > LOG_INFO) {
> -		id = __be64_to_cpup((__be64 *) keyid);
> -		sprintf(str, "%llX", (unsigned long long)id);
> +	if (params.verbose > LOG_INFO)
>  		log_info("keyid-v1: %s\n", str);
> -	}
>  }
> 
>  void calc_keyid_v2(uint32_t *keyid, char *str, RSA *key)
> @@ -694,11 +693,10 @@ void calc_keyid_v2(uint32_t *keyid, char *str, RSA *key)
>  	memcpy(keyid, sha1 + 16, 4);
>  	log_debug("keyid: ");
>  	log_debug_dump(keyid, 4);
> +	sprintf(str, "%x", __be32_to_cpup(keyid));
> 
> -	if (params.verbose > LOG_INFO) {
> -		sprintf(str, "%x", __be32_to_cpup(keyid));
> +	if (params.verbose > LOG_INFO)
>  		log_info("keyid: %s\n", str);
> -	}
> 
>  	free(pkey);
>  }