[2663] in Kerberos-V5-bugs
krb5-libs/371: keytab library should cache most-recently-used keytab entry
daemon@ATHENA.MIT.EDU (Jonathan I. Kamens)
Wed Feb 12 12:22:18 1997
Resent-From: gnats@rt-11.MIT.EDU (GNATS Management)
Resent-To: krb5-unassigned@RT-11.MIT.EDU
Resent-Reply-To: krb5-bugs@MIT.EDU, jik@kamens.brookline.ma.us
Date: Wed, 12 Feb 1997 12:20:21 -0500
From: "Jonathan I. Kamens" <jik@kamens.brookline.ma.us>
Reply-To: jik@kamens.brookline.ma.us
To: krb5-bugs@MIT.EDU
>Number: 371
>Category: krb5-libs
>Synopsis: keytab library should cache most-recently-used keytab entry
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: krb5-unassigned
>State: open
>Class: sw-bug
>Submitter-Id: unknown
>Arrival-Date: Wed Feb 12 12:17:01 EST 1997
>Last-Modified:
>Originator: Jonathan I. Kamens
>Organization:
OpenVision Technologies, Inc.
>Release: 1.0
>Environment:
N/A
>Description:
The speed of krb5_kt_get_entry() for persistent applications
can be greatly improved by making it cache the keytab entry most
recently returned to a caller, so that if a subsequent request is for
the same keytab entry, it can be returned without needing to open and
scan the keytab file again.
This doesn't provide a significant performance improvement on
systems which cache files in memory and whose disks aren't very busy,
but it will improve performance on systems which don't cache files
and/or which are busy enough that the keytab file isn't kept in the
cache all the time.
>How-To-Repeat:
>Fix:
--- krb5-1.0/src/lib/krb5/keytab/file/ktf_close.c Thu Apr 13 20:53:11 1995
+++ krb5-1.0/src/lib/krb5/keytab/file/ktf_close.c Wed Feb 12 09:30:54 1997
@@ -41,6 +41,8 @@
*/
{
krb5_xfree(KTFILENAME(id));
+ if (KTCACHE(id).magic)
+ krb5_kt_free_entry(context, &KTCACHE(id));
krb5_xfree(id->data);
id->ops = 0;
krb5_xfree(id);
--- krb5-1.0/src/lib/krb5/keytab/file/ktf_g_ent.c Tue Nov 19 17:07:30 1996
+++ krb5-1.0/src/lib/krb5/keytab/file/ktf_g_ent.c Wed Feb 12 09:17:08 1997
@@ -41,6 +41,42 @@
krb5_keytab_entry cur_entry, new_entry;
krb5_error_code kerror = 0;
int found_wrong_kvno = 0;
+ krb5_enctype entry_type;
+
+ switch (enctype) {
+ case ENCTYPE_DES_CBC_CRC:
+ case ENCTYPE_DES_CBC_MD5:
+ case ENCTYPE_DES_CBC_MD4:
+ case ENCTYPE_DES_CBC_RAW:
+ enctype = ENCTYPE_DES_CBC_CRC;
+ break;
+ }
+
+ if (KTCACHE(id).magic) {
+ new_entry = KTCACHE(id);
+
+ entry_type = new_entry.key.enctype;
+ switch(entry_type) {
+ case ENCTYPE_DES_CBC_CRC:
+ case ENCTYPE_DES_CBC_MD5:
+ case ENCTYPE_DES_CBC_MD4:
+ case ENCTYPE_DES_CBC_RAW:
+ entry_type = ENCTYPE_DES_CBC_CRC;
+ break;
+ }
+
+ if (((enctype == IGNORE_ENCTYPE) || (enctype == entry_type)) &&
+ krb5_principal_compare(context, principal, new_entry.principal) &&
+ ((kvno == IGNORE_VNO) || (kvno == new_entry.vno))) {
+ if ((kerror = krb5_ktfileint_copy_entry(context, &new_entry, entry)))
+ return(kerror);
+ return 0;
+ }
+ else {
+ krb5_kt_free_entry(context, &new_entry);
+ KTCACHE(id).magic = 0;
+ }
+ }
/* Open the keyfile for reading */
if ((kerror = krb5_ktfileint_openr(context, id)))
@@ -54,20 +90,9 @@
cur_entry.vno = 0;
cur_entry.key.contents = 0;
while (TRUE) {
- krb5_enctype entry_type;
-
if ((kerror = krb5_ktfileint_read_entry(context, id, &new_entry)))
break;
- switch (enctype) {
- case ENCTYPE_DES_CBC_CRC:
- case ENCTYPE_DES_CBC_MD5:
- case ENCTYPE_DES_CBC_MD4:
- case ENCTYPE_DES_CBC_RAW:
- enctype = ENCTYPE_DES_CBC_CRC;
- break;
- }
-
entry_type = new_entry.key.enctype;
switch(entry_type) {
case ENCTYPE_DES_CBC_CRC:
@@ -118,5 +143,6 @@
return kerror;
}
*entry = cur_entry;
+ (void) krb5_ktfileint_copy_entry(context, &cur_entry, &KTCACHE(id));
return 0;
}
--- krb5-1.0/src/lib/krb5/keytab/file/ktf_resolv.c Tue Aug 29 14:34:32 1995
+++ krb5-1.0/src/lib/krb5/keytab/file/ktf_resolv.c Wed Feb 12 09:17:33 1997
@@ -53,6 +53,7 @@
(void) strcpy(data->name, name);
data->openf = 0;
+ memset(&data->cache, 0, sizeof(data->cache));
(*id)->data = (krb5_pointer)data;
(*id)->magic = KV5M_KEYTAB;
--- krb5-1.0/src/lib/krb5/keytab/file/ktf_util.c Mon Sep 11 21:25:09 1995
+++ krb5-1.0/src/lib/krb5/keytab/file/ktf_util.c Wed Feb 12 09:24:54 1997
@@ -771,3 +771,31 @@
return 0;
}
+/*
+ * Copy a keytab entry's data from an old structure into a new
+ * (already allocated) structure.
+ */
+
+krb5_error_code
+krb5_ktfileint_copy_entry(context, old_entry, new_entry)
+ krb5_context context;
+ krb5_keytab_entry *old_entry, *new_entry;
+{
+ krb5_error_code code;
+ krb5_keytab_entry tmp_entry;
+
+ tmp_entry = *old_entry;
+
+ if ((code = krb5_copy_principal(context, old_entry->principal,
+ &tmp_entry.principal)))
+ return code;
+
+ if ((code = krb5_copy_keyblock_contents(context, &old_entry->key,
+ &tmp_entry.key))) {
+ (void) krb5_free_principal(context, tmp_entry.principal);
+ return code;
+ }
+
+ *new_entry = tmp_entry;
+ return 0;
+}
--- krb5-1.0/src/lib/krb5/keytab/file/ktf_wreslv.c Tue Aug 29 14:34:35 1995
+++ krb5-1.0/src/lib/krb5/keytab/file/ktf_wreslv.c Wed Feb 12 09:18:15 1997
@@ -53,6 +53,7 @@
(void) strcpy(data->name, name);
data->openf = 0;
+ memset(&data->cache, 0, sizeof(data->cache));
(*id)->data = (krb5_pointer)data;
(*id)->magic = KV5M_KEYTAB;
--- krb5-1.0/src/lib/krb5/keytab/file/ktfile.h Fri Jan 26 00:20:17 1996
+++ krb5-1.0/src/lib/krb5/keytab/file/ktfile.h Wed Feb 12 09:16:18 1997
@@ -49,6 +49,7 @@
char *name; /* Name of the file */
FILE *openf; /* open file, if any. */
int version; /* Version number of keytab */
+ krb5_keytab_entry cache; /* Cached last keytab entry returned by get_entry */
} krb5_ktfile_data;
/*
@@ -58,6 +59,7 @@
#define KTFILENAME(id) (((krb5_ktfile_data *)(id)->data)->name)
#define KTFILEP(id) (((krb5_ktfile_data *)(id)->data)->openf)
#define KTVERSION(id) (((krb5_ktfile_data *)(id)->data)->version)
+#define KTCACHE(id) (((krb5_ktfile_data *)(id)->data)->cache)
extern struct _krb5_kt_ops krb5_ktf_ops;
extern struct _krb5_kt_ops krb5_ktf_writable_ops;
@@ -160,6 +162,11 @@
krb5_keytab,
krb5_int32 *,
krb5_int32 *));
+
+krb5_error_code krb5_ktfileint_copy_entry
+ PROTOTYPE((krb5_context,
+ krb5_keytab_entry *,
+ krb5_keytab_entry *));
#endif /* KRB5_KTFILE__ */
>Audit-Trail:
>Unformatted:
