krb5: add copy_keytab_into_memory()

2 files changed, 153 insertions, 0 deletions

diff --git a/src/providers/krb5/krb5_common.h b/src/providers/krb5/krb5_common.h
index a5cee6497..5936bd437 100644
--- a/src/providers/krb5/krb5_common.h
+++ b/src/providers/krb5/krb5_common.h
@@ -189,4 +189,8 @@ int sssm_krb5_auth_init(struct be_ctx *bectx,
                         struct bet_ops **ops,
                         void **pvt_auth_data);
 
+/* from krb5_keytab.c */
+krb5_error_code copy_keytab_into_memory(TALLOC_CTX *mem_ctx, krb5_context kctx,
+                                        const char *keytab_file,
+                                        char **_mem_name);
 #endif /* __KRB5_COMMON_H__ */
diff --git a/src/providers/krb5/krb5_keytab.c b/src/providers/krb5/krb5_keytab.c
new file mode 100644
index 000000000..79a9db184
--- /dev/null
+++ b/src/providers/krb5/krb5_keytab.c
@@ -0,0 +1,149 @@
+/*
+    SSSD
+
+    Kerberos 5 Backend Module -- keytab related utilities
+
+    Authors:
+        Sumit Bose <sbose@redhat.com>
+
+    Copyright (C) 2014 Red Hat
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "util/util.h"
+#include "util/sss_krb5.h"
+
+krb5_error_code copy_keytab_into_memory(TALLOC_CTX *mem_ctx, krb5_context kctx,
+                                        const char *keytab_file,
+                                        char **_mem_name)
+{
+    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;
+    char keytab_name[MAX_KEYTAB_NAME_LEN];
+    char *sep;
+    char *mem_name = NULL;
+
+    kerr = krb5_kt_resolve(kctx, keytab_file, &keytab);
+    if (kerr != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "error resolving keytab [%s].\n",
+                                    keytab_file);
+        return kerr;
+    }
+
+    kerr = krb5_kt_have_content(kctx, keytab);
+    if (kerr != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "keytab [%s] has not entries.\n",
+                                    keytab_file);
+        goto done;
+    }
+
+    kerr = krb5_kt_get_name(kctx, keytab, keytab_name, sizeof(keytab_name));
+    if (kerr != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Failed to read name for keytab [%s].\n",
+                                    keytab_file);
+        goto done;
+    }
+
+    sep = strchr(keytab_name, ':');
+    if (sep == NULL || sep[1] == '\0') {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Keytab name [%s] does not have delimiter[:] .\n", keytab_name);
+        kerr = KRB5KRB_ERR_GENERIC;
+        goto done;
+    }
+
+    if (strncmp(keytab_name, "MEMORY:", sizeof("MEMORY:") -1) == 0) {
+        DEBUG(SSSDBG_TRACE_FUNC, "Keytab [%s] is already memory keytab.\n",
+                                 keytab_name);
+        *_mem_name = talloc_strdup(mem_ctx, keytab_name);
+        if(*_mem_name == NULL) {
+            DEBUG(SSSDBG_OP_FAILURE, "talloc_strdup failed.\n");
+            kerr = KRB5KRB_ERR_GENERIC;
+            goto done;
+        }
+        kerr = 0;
+        goto done;
+    }
+
+    mem_name = talloc_asprintf(mem_ctx, "MEMORY:%s", sep + 1);
+    if (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",
+                                    mem_name);
+        goto done;
+    }
+
+    memset(&cursor, 0, sizeof(cursor));
+    kerr = krb5_kt_start_seq_get(kctx, keytab, &cursor);
+    if (kerr != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "error reading keytab [%s].\n", keytab_file);
+        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);
+    if (kerr != 0) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "krb5_kt_end_seq_get failed.\n");
+        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;
+        goto done;
+    }
+
+    *_mem_name = mem_name;
+    kerr = 0;
+done:
+
+    if (kerr != 0) {
+        talloc_free(mem_name);
+    }
+
+//    if (mem_keytab != NULL && krb5_kt_close(kctx, mem_keytab) != 0) {
+//            DEBUG(SSSDBG_MINOR_FAILURE, "krb5_kt_close failed");
+//    }
+    if (keytab != NULL && krb5_kt_close(kctx, keytab) != 0) {
+            DEBUG(SSSDBG_MINOR_FAILURE, "krb5_kt_close failed");
+    }
+
+    return kerr;
+}