From 7c20e30182e3b5f7f8ebcd8174bded4dcc2f89a8 Mon Sep 17 00:00:00 2001
From: Sumit Bose <sbose@redhat.com>
Date: Thu, 15 Jan 2015 10:38:33 +0100
Subject: [PATCH 169/169] krb5: fix entry order in MEMORY keytab
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Since krb5_kt_add_entry() adds new entries at the beginning of a MEMORY
type keytab and not at the end a simple copy into a MEMORY type keytab
will revert the order of the keytab entries. Since e.g. the sssd_krb5
man page give hints about where to add entries into keytab files to help
SSSD to find a right entry we have to keep the order when coping a
keytab into a MEMORY type keytab. This patch fixes this by doing a
second copy to retain the original order.
Resolves https://fedorahosted.org/sssd/ticket/2557
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
(cherry picked from commit 24df1487413d13248dcc70d2548a763930da4c65)
---
src/providers/krb5/krb5_keytab.c | 118 +++++++++++++++++++++++++++++----------
1 file changed, 90 insertions(+), 28 deletions(-)
diff --git a/src/providers/krb5/krb5_keytab.c b/src/providers/krb5/krb5_keytab.c
index 855f69419611b863a7aea79e2788272f819b0736..ec8d6502d89c0d7f75c28b151523d235b6bc131d 100644
--- a/src/providers/krb5/krb5_keytab.c
+++ b/src/providers/krb5/krb5_keytab.c
@@ -25,20 +25,78 @@
#include "util/util.h"
#include "util/sss_krb5.h"
+static krb5_error_code do_keytab_copy(krb5_context kctx, krb5_keytab s_keytab,
+ krb5_keytab d_keytab)
+{
+ krb5_error_code kerr;
+ krb5_error_code kt_err;
+ krb5_kt_cursor cursor;
+ krb5_keytab_entry entry;
+
+ memset(&cursor, 0, sizeof(cursor));
+ kerr = krb5_kt_start_seq_get(kctx, s_keytab, &cursor);
+ if (kerr != 0) {
+ DEBUG(SSSDBG_CRIT_FAILURE, "error reading keytab.\n");
+ return kerr;
+ }
+
+ memset(&entry, 0, sizeof(entry));
+ while ((kt_err = krb5_kt_next_entry(kctx, s_keytab, &entry,
+ &cursor)) == 0) {
+ kerr = krb5_kt_add_entry(kctx, d_keytab, &entry);
+ if (kerr != 0) {
+ DEBUG(SSSDBG_OP_FAILURE, "krb5_kt_add_entry failed.\n");
+ kt_err = krb5_kt_end_seq_get(kctx, s_keytab, &cursor);
+ if (kt_err != 0) {
+ DEBUG(SSSDBG_TRACE_ALL,
+ "krb5_kt_end_seq_get failed with [%d], ignored.\n",
+ kt_err);
+ }
+ return kerr;
+ }
+
+ kerr = sss_krb5_free_keytab_entry_contents(kctx, &entry);
+ if (kerr != 0) {
+ DEBUG(SSSDBG_MINOR_FAILURE, "Failed to free keytab entry.\n");
+ kt_err = krb5_kt_end_seq_get(kctx, s_keytab, &cursor);
+ if (kt_err != 0) {
+ DEBUG(SSSDBG_TRACE_ALL,
+ "krb5_kt_end_seq_get failed with [%d], ignored.\n",
+ kt_err);
+ }
+ return kerr;
+ }
+ memset(&entry, 0, sizeof(entry));
+ }
+
+ kerr = krb5_kt_end_seq_get(kctx, s_keytab, &cursor);
+ if (kerr != 0) {
+ DEBUG(SSSDBG_CRIT_FAILURE, "krb5_kt_end_seq_get failed.\n");
+ return kerr;
+ }
+
+ /* check if we got any errors from krb5_kt_next_entry */
+ if (kt_err != 0 && kt_err != KRB5_KT_END) {
+ DEBUG(SSSDBG_CRIT_FAILURE, "error reading keytab.\n");
+ return kt_err;
+ }
+
+ return 0;
+}
+
krb5_error_code copy_keytab_into_memory(TALLOC_CTX *mem_ctx, krb5_context kctx,
char *inp_keytab_file,
char **_mem_name,
krb5_keytab *_mem_keytab)
{
krb5_error_code kerr;
- krb5_error_code kt_err;
krb5_keytab keytab = NULL;
krb5_keytab mem_keytab = NULL;
- krb5_kt_cursor cursor;
- krb5_keytab_entry entry;
+ krb5_keytab tmp_mem_keytab = NULL;
char keytab_name[MAX_KEYTAB_NAME_LEN];
char *sep;
char *mem_name = NULL;
+ char *tmp_mem_name = NULL;
char *keytab_file;
char default_keytab_name[MAX_KEYTAB_NAME_LEN];
@@ -103,6 +161,13 @@ krb5_error_code copy_keytab_into_memory(TALLOC_CTX *mem_ctx, krb5_context kctx,
goto done;
}
+ tmp_mem_name = talloc_asprintf(mem_ctx, "MEMORY:%s.tmp", sep + 1);
+ if (tmp_mem_name == NULL) {
+ DEBUG(SSSDBG_OP_FAILURE, "talloc_asprintf failed.\n");
+ kerr = KRB5KRB_ERR_GENERIC;
+ goto done;
+ }
+
kerr = krb5_kt_resolve(kctx, mem_name, &mem_keytab);
if (kerr != 0) {
DEBUG(SSSDBG_CRIT_FAILURE, "error resolving keytab [%s].\n",
@@ -110,38 +175,29 @@ krb5_error_code copy_keytab_into_memory(TALLOC_CTX *mem_ctx, krb5_context kctx,
goto done;
}
- memset(&cursor, 0, sizeof(cursor));
- kerr = krb5_kt_start_seq_get(kctx, keytab, &cursor);
+ kerr = krb5_kt_resolve(kctx, tmp_mem_name, &tmp_mem_keytab);
if (kerr != 0) {
- DEBUG(SSSDBG_CRIT_FAILURE, "error reading keytab [%s].\n", keytab_file);
+ DEBUG(SSSDBG_CRIT_FAILURE, "error resolving keytab [%s].\n",
+ tmp_mem_name);
goto done;
}
- memset(&entry, 0, sizeof(entry));
- while ((kt_err = krb5_kt_next_entry(kctx, keytab, &entry, &cursor)) == 0) {
- kerr = krb5_kt_add_entry(kctx, mem_keytab, &entry);
- if (kerr != 0) {
- DEBUG(SSSDBG_OP_FAILURE, "krb5_kt_add_entry failed.\n");
- goto done;
- }
-
- kerr = sss_krb5_free_keytab_entry_contents(kctx, &entry);
- if (kerr != 0) {
- DEBUG(SSSDBG_MINOR_FAILURE, "Failed to free keytab entry.\n");
- }
- memset(&entry, 0, sizeof(entry));
- }
-
- kerr = krb5_kt_end_seq_get(kctx, keytab, &cursor);
+ kerr = do_keytab_copy(kctx, keytab, tmp_mem_keytab);
if (kerr != 0) {
- DEBUG(SSSDBG_CRIT_FAILURE, "krb5_kt_end_seq_get failed.\n");
+ DEBUG(SSSDBG_CRIT_FAILURE, "Failed to copy keytab [%s] into [%s].\n",
+ keytab_file, tmp_mem_name);
goto done;
}
- /* check if we got any errors from krb5_kt_next_entry */
- if (kt_err != 0 && kt_err != KRB5_KT_END) {
- DEBUG(SSSDBG_CRIT_FAILURE, "error reading keytab [%s].\n", keytab_file);
- kerr = KRB5KRB_ERR_GENERIC;
+ /* krb5_kt_add_entry() adds new entries into MEMORY keytabs at the
+ * beginning and not at the end as for FILE keytabs. Since we want to keep
+ * the processing order we have to copy the MEMORY keytab again to retain
+ * the order from the FILE keytab. */
+
+ kerr = do_keytab_copy(kctx, tmp_mem_keytab, mem_keytab);
+ if (kerr != 0) {
+ DEBUG(SSSDBG_CRIT_FAILURE, "Failed to copy keytab [%s] into [%s].\n",
+ tmp_mem_name, mem_name);
goto done;
}
@@ -153,12 +209,18 @@ krb5_error_code copy_keytab_into_memory(TALLOC_CTX *mem_ctx, krb5_context kctx,
kerr = 0;
done:
+ talloc_free(tmp_mem_name);
+
if (kerr != 0) {
talloc_free(mem_name);
}
+ if (tmp_mem_keytab != NULL && krb5_kt_close(kctx, tmp_mem_keytab) != 0) {
+ DEBUG(SSSDBG_MINOR_FAILURE, "krb5_kt_close failed.\n");
+ }
+
if (keytab != NULL && krb5_kt_close(kctx, keytab) != 0) {
- DEBUG(SSSDBG_MINOR_FAILURE, "krb5_kt_close failed");
+ DEBUG(SSSDBG_MINOR_FAILURE, "krb5_kt_close failed.\n");
}
return kerr;
--
2.1.0