encrypted-keys: added additional debug messages

Some debug messages have been added in the function datablob_parse() in
order to better identify errors returned when dealing with 'encrypted'
keys.

Changelog from version v4:
- made the debug messages more understandable 

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Acked-by: Gianluca Ramunno <ramunno@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

1 files changed, 34 insertions, 11 deletions

diff --git a/security/keys/encrypted.c b/security/keys/encrypted.c
index 3ff2f72dad94..f36a105de791 100644
--- a/security/keys/encrypted.c
+++ b/security/keys/encrypted.c
@@ -133,46 +133,69 @@ static int datablob_parse(char *datablob, char **master_desc,
         substring_t args[MAX_OPT_ARGS];
         int ret = -EINVAL;
         int key_cmd;
-        char *p;
+        char *keyword;
 
-        p = strsep(&datablob, " \t");
-        if (!p)
+        keyword = strsep(&datablob, " \t");
+        if (!keyword) {
+                pr_info("encrypted_key: insufficient parameters specified\n");
                 return ret;
-        key_cmd = match_token(p, key_tokens, args);
+        }
+        key_cmd = match_token(keyword, key_tokens, args);
 
         *master_desc = strsep(&datablob, " \t");
-        if (!*master_desc)
+        if (!*master_desc) {
+                pr_info("encrypted_key: master key parameter is missing\n");
                 goto out;
+        }
 
-        if (valid_master_desc(*master_desc, NULL) < 0)
+        if (valid_master_desc(*master_desc, NULL) < 0) {
+                pr_info("encrypted_key: master key parameter \'%s\' "
+                        "is invalid\n", *master_desc);
                 goto out;
+        }
 
         if (decrypted_datalen) {
                 *decrypted_datalen = strsep(&datablob, " \t");
-                if (!*decrypted_datalen)
+                if (!*decrypted_datalen) {
+                        pr_info("encrypted_key: keylen parameter is missing\n");
                         goto out;
+                }
         }
 
         switch (key_cmd) {
         case Opt_new:
-                if (!decrypted_datalen)
+                if (!decrypted_datalen) {
+                        pr_info("encrypted_key: keyword \'%s\' not allowed "
+                                "when called from .update method\n", keyword);
                         break;
+                }
                 ret = 0;
                 break;
         case Opt_load:
-                if (!decrypted_datalen)
+                if (!decrypted_datalen) {
+                        pr_info("encrypted_key: keyword \'%s\' not allowed "
+                                "when called from .update method\n", keyword);
                         break;
+                }
                 *hex_encoded_iv = strsep(&datablob, " \t");
-                if (!*hex_encoded_iv)
+                if (!*hex_encoded_iv) {
+                        pr_info("encrypted_key: hex blob is missing\n");
                         break;
+                }
                 ret = 0;
                 break;
         case Opt_update:
-                if (decrypted_datalen)
+                if (decrypted_datalen) {
+                        pr_info("encrypted_key: keyword \'%s\' not allowed "
+                                "when called from .instantiate method\n",
+                                keyword);
                         break;
+                }
                 ret = 0;
                 break;
         case Opt_err:
+                pr_info("encrypted_key: keyword \'%s\' not recognized\n",
+                        keyword);
                 break;
         }
 out: