clikrb5: Move pure krb wrapper functions from libads to clikrb5.

Signed-off-by: Andreas Schneider <asn@samba.org>

1 files changed, 142 insertions, 0 deletions

diff --git a/source3/libsmb/clikrb5.c b/source3/libsmb/clikrb5.c
index 9e03b30c35..792400b3ce 100644
--- a/source3/libsmb/clikrb5.c
+++ b/source3/libsmb/clikrb5.c
@@ -1439,6 +1439,148 @@ char *smb_krb5_principal_get_realm(krb5_context context,
 #endif
 }
 
+/************************************************************************
+ Routine to get the default realm from the kerberos credentials cache.
+ Caller must free if the return value is not NULL.
+************************************************************************/
+
+static char *smb_krb5_get_default_realm_from_ccache(TALLOC_CTX *mem_ctx)
+{
+	char *realm = NULL;
+	krb5_context ctx = NULL;
+	krb5_ccache cc = NULL;
+	krb5_principal princ = NULL;
+
+	initialize_krb5_error_table();
+	if (krb5_init_context(&ctx)) {
+		return NULL;
+	}
+
+	DEBUG(5,("kerberos_get_default_realm_from_ccache: "
+		"Trying to read krb5 cache: %s\n",
+		krb5_cc_default_name(ctx)));
+	if (krb5_cc_default(ctx, &cc)) {
+		DEBUG(0,("kerberos_get_default_realm_from_ccache: "
+			"failed to read default cache\n"));
+		goto out;
+	}
+	if (krb5_cc_get_principal(ctx, cc, &princ)) {
+		DEBUG(0,("kerberos_get_default_realm_from_ccache: "
+			"failed to get default principal\n"));
+		goto out;
+	}
+
+#if defined(HAVE_KRB5_PRINCIPAL_GET_REALM)
+	realm = talloc_strdup(mem_ctx, krb5_principal_get_realm(ctx, princ));
+#elif defined(HAVE_KRB5_PRINC_REALM)
+	{
+		krb5_data *realm_data = krb5_princ_realm(ctx, princ);
+		realm = talloc_strndup(mem_ctx, realm_data->data, realm_data->length);
+	}
+#endif
+
+  out:
+
+	if (ctx) {
+		if (princ) {
+			krb5_free_principal(ctx, princ);
+		}
+		if (cc) {
+			krb5_cc_close(ctx, cc);
+		}
+		krb5_free_context(ctx);
+	}
+
+	return realm;
+}
+
+/************************************************************************
+ Routine to get the realm from a given DNS name.
+************************************************************************/
+
+static char *smb_krb5_get_realm_from_hostname(TALLOC_CTX *mem_ctx,
+						const char *hostname)
+{
+#if defined(HAVE_KRB5_REALM_TYPE)
+	/* Heimdal. */
+	krb5_realm *realm_list = NULL;
+#else
+	/* MIT */
+	char **realm_list = NULL;
+#endif
+	char *realm = NULL;
+	krb5_error_code kerr;
+	krb5_context ctx = NULL;
+
+	initialize_krb5_error_table();
+	if (krb5_init_context(&ctx)) {
+		return NULL;
+	}
+
+	kerr = krb5_get_host_realm(ctx, hostname, &realm_list);
+	if (kerr != 0) {
+		DEBUG(3,("kerberos_get_realm_from_hostname %s: "
+			"failed %s\n",
+			hostname ? hostname : "(NULL)",
+			error_message(kerr) ));
+		goto out;
+	}
+
+	if (realm_list && realm_list[0]) {
+		realm = talloc_strdup(mem_ctx, realm_list[0]);
+	}
+
+  out:
+
+	if (ctx) {
+		if (realm_list) {
+			krb5_free_host_realm(ctx, realm_list);
+			realm_list = NULL;
+		}
+		krb5_free_context(ctx);
+		ctx = NULL;
+	}
+	return realm;
+}
+
+char *kerberos_get_principal_from_service_hostname(TALLOC_CTX *mem_ctx,
+						   const char *service,
+						   const char *remote_name)
+{
+	char *realm = NULL;
+	char *host = NULL;
+	char *principal;
+	host = strchr_m(remote_name, '.');
+	if (host) {
+		/* DNS name. */
+		realm = smb_krb5_get_realm_from_hostname(talloc_tos(),
+							 remote_name);
+	} else {
+		/* NetBIOS name - use our realm. */
+		realm = smb_krb5_get_default_realm_from_ccache(talloc_tos());
+	}
+
+	if (realm == NULL || *realm == '\0') {
+		realm = talloc_strdup(talloc_tos(), lp_realm());
+		if (!realm) {
+			return NULL;
+		}
+		DEBUG(3,("kerberos_get_principal_from_service_hostname: "
+			 "cannot get realm from, "
+			 "desthost %s or default ccache. Using default "
+			 "smb.conf realm %s\n",
+			 remote_name,
+			 realm));
+	}
+
+	principal = talloc_asprintf(mem_ctx,
+				    "%s/%s@%s",
+				    service, remote_name,
+				    realm);
+	TALLOC_FREE(realm);
+	return principal;
+}
+
 #else /* HAVE_KRB5 */
  /* this saves a few linking headaches */
  int cli_krb5_get_ticket(TALLOC_CTX *mem_ctx,