Jan Zelený <jzel...@redhat.com> wrote:
> Jan Zelený <jzel...@redhat.com> wrote:
> > This functionality will be required in tickets #781 and #700.
> >
> > Jan
>
> This is corrected version - removes some compilation-time error messages.
>
> Jan
Another correction: the code mixup has been eliminated.
Jan
From f750219f1ee65217974b9ed192a745fb086b757b Mon Sep 17 00:00:00 2001
From: Jan Zeleny <jzel...@redhat.com>
Date: Tue, 29 Mar 2011 02:50:28 -0400
Subject: [PATCH] Extend and move function for finding principal in keytab
The function now supports finding principal in keytab not only based on
realm, but based on both realm and primary/instance parts. The function
also supports * wildcard at the beginning or at the end of primary
principal part. The function for finding principal has been moved to
util/sss_krb5.c, so it can be used in other parts of the code.
---
src/providers/krb5/krb5_child.c | 82 +--------------------
src/util/sss_krb5.c | 159 +++++++++++++++++++++++++++++++++++++++
src/util/sss_krb5.h | 6 ++
3 files changed, 167 insertions(+), 80 deletions(-)
diff --git a/src/providers/krb5/krb5_child.c b/src/providers/krb5/krb5_child.c
index 335da423c1752bf113ef1dae6a324cff1b964976..1ed63f6b2583c2fad267ad04ab0e32bd7f6d327b 100644
--- a/src/providers/krb5/krb5_child.c
+++ b/src/providers/krb5/krb5_child.c
@@ -30,6 +30,7 @@
#include <security/pam_modules.h>
#include "util/util.h"
+#include "util/sss_krb5.h"
#include "util/user_info_msg.h"
#include "providers/child_common.h"
#include "providers/dp_backend.h"
@@ -492,85 +493,6 @@ static errno_t add_ticket_times_to_response(struct krb5_req *kr)
return ret;
}
-static krb5_error_code find_principal_in_keytab(krb5_context ctx,
- krb5_keytab keytab,
- const char *realm,
- krb5_principal *princ)
-{
- krb5_error_code kerr;
- krb5_error_code kt_err;
- krb5_error_code kerr_d;
- krb5_kt_cursor cursor;
- krb5_keytab_entry entry;
- bool principal_found = false;
-
- memset(&cursor, 0, sizeof(cursor));
- kerr = krb5_kt_start_seq_get(ctx, keytab, &cursor);
- if (kerr != 0) {
- DEBUG(1, ("krb5_kt_start_seq_get failed.\n"));
- KRB5_DEBUG(1, kerr);
- return kerr;
- }
-
- /* We look for the first entry from our realm or take the last one */
- memset(&entry, 0, sizeof(entry));
- while ((kt_err = krb5_kt_next_entry(ctx, keytab, &entry, &cursor)) == 0) {
- if (krb5_princ_realm(ctx, entry.principal)->length == strlen(realm) &&
- strncmp(krb5_princ_realm(ctx, entry.principal)->data, realm,
- krb5_princ_realm(ctx, entry.principal)->length) == 0) {
- DEBUG(9, ("Found keytab entry with the realm of the credential.\n"));
- principal_found = true;
- break;
- }
-
- kerr = krb5_free_keytab_entry_contents(ctx, &entry);
- if (kerr != 0) {
- DEBUG(1, ("Failed to free keytab entry.\n"));
- }
- memset(&entry, 0, sizeof(entry));
- }
-
- /* Close the keytab here. Even though we're using cursors, the file
- * handle is stored in the krb5_keytab structure, and it gets
- * overwritten by other keytab calls, creating a leak. */
- kerr = krb5_kt_end_seq_get(ctx, keytab, &cursor);
- if (kerr != 0) {
- DEBUG(1, ("krb5_kt_end_seq_get failed.\n"));
- goto done;
- }
-
- if (!principal_found) {
- kerr = KRB5_KT_NOTFOUND;
- DEBUG(1, ("No principal from realm [%s] found in keytab.\n", realm));
- goto done;
- }
-
- /* check if we got any errors from krb5_kt_next_entry */
- if (kt_err != 0 && kt_err != KRB5_KT_END) {
- DEBUG(1, ("Error while reading keytab.\n"));
- KRB5_DEBUG(1, kerr);
- goto done;
- }
-
- kerr = krb5_copy_principal(ctx, entry.principal, princ);
- if (kerr != 0) {
- DEBUG(1, ("krb5_copy_principal failed.\n"));
- KRB5_DEBUG(1, kerr);
- goto done;
- }
-
- kerr = 0;
-
-done:
- kerr_d = krb5_free_keytab_entry_contents(ctx, &entry);
- if (kerr_d != 0) {
- DEBUG(1, ("Failed to free keytab entry.\n"));
- KRB5_DEBUG(1, kerr_d);
- }
-
- return kerr;
-}
-
static krb5_error_code validate_tgt(struct krb5_req *kr)
{
krb5_error_code kerr;
@@ -1338,7 +1260,7 @@ static krb5_error_code check_fast_ccache(krb5_context ctx, const char *realm,
goto done;
}
- kerr = find_principal_in_keytab(ctx, keytab, realm, &client_princ);
+ kerr = find_principal_in_keytab(ctx, keytab, NULL, realm, &client_princ);
if (kerr != 0) {
DEBUG(1, ("find_principal_in_keytab failed.\n"));
goto done;
diff --git a/src/util/sss_krb5.c b/src/util/sss_krb5.c
index 894dd443d02f4f0549f4e50d1aff87be3f1c74e8..4c78cc0911d9369e0dafb920cbd276c2b79a56ad 100644
--- a/src/util/sss_krb5.c
+++ b/src/util/sss_krb5.c
@@ -188,6 +188,165 @@ int sss_krb5_verify_keytab_ex(const char *principal, const char *keytab_name,
return EOK;
}
+
+enum matching_mode {MODE_NORMAL, MODE_PREFIX, MODE_POSTFIX};
+/**
+ * We only have primary and instances stored separately, we need to
+ * join them to one string and compare that string.
+ *
+ * @param ctx kerberos context
+ * @param principal principal we want to match
+ * @param pattern_primary primary part of the principal we want to
+ * perform matching against. It is possible to use * wildcard
+ * at the beginning or at the end of the string. If NULL, it
+ * will act as "*"
+ * @param pattern_realm realm part of the principal we want to perform
+ * the matching against. If NULL, it will act as "*"
+ */
+static bool match_principal(krb5_context ctx,
+ krb5_principal principal,
+ const char *pattern_primary,
+ const char *pattern_realm)
+{
+ krb5_data *realm_data;
+ char *primary = NULL;
+ char *primary_str = NULL;
+ int primary_str_len = 0;
+ int tmp_len;
+ int len_diff;
+
+ int mode = MODE_NORMAL;
+ TALLOC_CTX *tmp_ctx;
+ bool ret;
+ char *tmp_ptr;
+
+ realm_data = krb5_princ_realm(ctx, principal);
+
+ tmp_ctx = talloc_new(NULL);
+ if (!tmp_ctx) {
+ DEBUG(1, ("talloc_new failed\n"));
+ return false;
+ }
+
+ if (pattern_primary) {
+ tmp_len = strlen(pattern_primary);
+ if (pattern_primary[tmp_len] == '*') {
+ mode = MODE_PREFIX;
+ primary_str = talloc_strdup(tmp_ctx, pattern_primary);
+ primary_str[tmp_len] = '\0';
+ primary_str_len = tmp_len-1;
+ } else if (pattern_primary[0] == '*') {
+ mode = MODE_POSTFIX;
+ primary_str = talloc_strdup(tmp_ctx, pattern_primary+1);
+ primary_str_len = tmp_len-1;
+ }
+
+ krb5_unparse_name(ctx, principal, &primary);
+ tmp_ptr = strchr(primary, '@');
+ if (tmp_ptr) {
+ *tmp_ptr = '\0';
+ }
+
+ len_diff = strlen(primary)-primary_str_len;
+
+ if ((mode == MODE_NORMAL &&
+ strcmp(primary, pattern_primary) != 0) ||
+ (mode == MODE_PREFIX &&
+ strncmp(primary, primary_str, primary_str_len) != 0) ||
+ (mode == MODE_POSTFIX &&
+ strcmp(primary+len_diff, primary_str) != 0)) {
+ ret = false;
+ goto done;
+ }
+ }
+
+ if (!pattern_realm || (realm_data->length == strlen(pattern_realm) &&
+ strncmp(realm_data->data, pattern_realm, realm_data->length) == 0)) {
+ DEBUG(7, ("Principal matched to the sample (%s@%s).\n", pattern_primary,
+ pattern_realm));
+ ret = true;
+ }
+
+done:
+ free(primary);
+ talloc_free(tmp_ctx);
+ return ret;
+}
+
+krb5_error_code find_principal_in_keytab(krb5_context ctx,
+ krb5_keytab keytab,
+ const char *pattern_primary,
+ const char *pattern_realm,
+ krb5_principal *princ)
+{
+ krb5_error_code kerr;
+ krb5_error_code kt_err;
+ krb5_error_code kerr_d;
+ krb5_kt_cursor cursor;
+ krb5_keytab_entry entry;
+ bool principal_found = false;
+
+ memset(&cursor, 0, sizeof(cursor));
+ kerr = krb5_kt_start_seq_get(ctx, keytab, &cursor);
+ if (kerr != 0) {
+ DEBUG(1, ("krb5_kt_start_seq_get failed.\n"));
+ return kerr;
+ }
+
+ DEBUG(9, ("Trying to find principal %s@%s in keytab.\n", pattern_primary, pattern_realm));
+ memset(&entry, 0, sizeof(entry));
+ while ((kt_err = krb5_kt_next_entry(ctx, keytab, &entry, &cursor)) == 0) {
+ principal_found = match_principal(ctx, entry.principal, pattern_primary, pattern_realm);
+ if (principal_found) {
+ break;
+ }
+
+ kerr = krb5_free_keytab_entry_contents(ctx, &entry);
+ if (kerr != 0) {
+ DEBUG(1, ("Failed to free keytab entry.\n"));
+ }
+ memset(&entry, 0, sizeof(entry));
+ }
+
+ /* Close the keytab here. Even though we're using cursors, the file
+ * handle is stored in the krb5_keytab structure, and it gets
+ * overwritten by other keytab calls, creating a leak. */
+ kerr = krb5_kt_end_seq_get(ctx, keytab, &cursor);
+ if (kerr != 0) {
+ DEBUG(1, ("krb5_kt_end_seq_get failed.\n"));
+ goto done;
+ }
+
+ if (!principal_found) {
+ kerr = KRB5_KT_NOTFOUND;
+ DEBUG(1, ("No principal matching %s@%s found in keytab.\n",
+ pattern_primary, pattern_realm));
+ goto done;
+ }
+
+ /* check if we got any errors from krb5_kt_next_entry */
+ if (kt_err != 0 && kt_err != KRB5_KT_END) {
+ DEBUG(1, ("Error while reading keytab.\n"));
+ goto done;
+ }
+
+ kerr = krb5_copy_principal(ctx, entry.principal, princ);
+ if (kerr != 0) {
+ DEBUG(1, ("krb5_copy_principal failed.\n"));
+ goto done;
+ }
+
+ kerr = 0;
+
+done:
+ kerr_d = krb5_free_keytab_entry_contents(ctx, &entry);
+ if (kerr_d != 0) {
+ DEBUG(1, ("Failed to free keytab entry.\n"));
+ }
+
+ return kerr;
+}
+
const char *KRB5_CALLCONV sss_krb5_get_error_message(krb5_context ctx,
krb5_error_code ec)
{
diff --git a/src/util/sss_krb5.h b/src/util/sss_krb5.h
index 0a82315cca48b5712a9f0225efbb374185144ec7..f25f3285b2cac8b37fde73985775c276c6ea589d 100644
--- a/src/util/sss_krb5.h
+++ b/src/util/sss_krb5.h
@@ -58,6 +58,12 @@ int sss_krb5_verify_keytab(const char *principal,
int sss_krb5_verify_keytab_ex(const char *principal, const char *keytab_name,
krb5_context context, krb5_keytab keytab);
+krb5_error_code find_principal_in_keytab(krb5_context ctx,
+ krb5_keytab keytab,
+ const char *pattern_primary,
+ const char *pattern_realm,
+ krb5_principal *princ);
+
#ifndef HAVE_KRB5_GET_INIT_CREDS_OPT_SET_EXPIRE_CALLBACK
typedef void krb5_expire_callback_func(krb5_context context, void *data,
krb5_timestamp password_expiration,
--
1.7.4.1
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