1 files changed, 108 insertions, 0 deletions
diff --git a/portable/krb5-extra.c b/portable/krb5-extra.c
new file mode 100644
index 0000000..09a717b
--- /dev/null
+++ b/portable/krb5-extra.c
@@ -0,0 +1,108 @@
+/*
+ * Portability glue functions for Kerberos.
+ *
+ * This file provides definitions of the interfaces that portable/krb5.h
+ * ensures exist if the function wasn't available in the Kerberos libraries.
+ * Everything in this file will be protected by #ifndef.  If the native
+ * Kerberos libraries are fully capable, this file will be skipped.
+ *
+ * Written by Russ Allbery <rra@stanford.edu>
+ * This work is hereby placed in the public domain by its author.
+ */
+
+#include <config.h>
+#include <portable/krb5.h>
+#include <portable/system.h>
+
+#include <errno.h>
+
+/* Figure out what header files to include for error reporting. */
+#if !defined(HAVE_KRB5_GET_ERROR_MESSAGE) && !defined(HAVE_KRB5_GET_ERR_TEXT)
+# if !defined(HAVE_KRB5_GET_ERROR_STRING)
+#  if defined(HAVE_IBM_SVC_KRB5_SVC_H)
+#   include <ibm_svc/krb5_svc.h>
+#  elif defined(HAVE_ET_COM_ERR_H)
+#   include <et/com_err.h>
+#  else
+#   include <com_err.h>
+#  endif
+# endif
+#endif
+
+/* Used for unused parameters to silence gcc warnings. */
+#define UNUSED __attribute__((__unused__))
+
+/*
+ * This string is returned for unknown error messages.  We use a static
+ * variable so that we can be sure not to free it.
+ */
+static const char error_unknown[] = "unknown error";
+
+
+#ifndef HAVE_KRB5_GET_ERROR_MESSAGE
+/*
+ * Given a Kerberos error code, return the corresponding error.  Prefer the
+ * Kerberos interface if available since it will provide context-specific
+ * error information, whereas the error_message() call will only provide a
+ * fixed message.
+ */
+const char *
+krb5_get_error_message(krb5_context ctx UNUSED, krb5_error_code code UNUSED)
+{
+    const char *msg = NULL;
+
+# if defined(HAVE_KRB5_GET_ERROR_STRING)
+    msg = krb5_get_error_string(ctx);
+# elif defined(HAVE_KRB5_GET_ERR_TEXT)
+    msg = krb5_get_err_text(ctx, code);
+# elif defined(HAVE_KRB5_SVC_GET_MSG)
+    krb5_svc_get_msg(code, (char **) &msg);
+# else
+    msg = error_message(code);
+# endif
+    if (msg == NULL)
+        return error_unknown;
+    else
+        return msg;
+}
+#endif /* !HAVE_KRB5_GET_ERROR_MESSAGE */
+
+
+#ifndef HAVE_KRB5_FREE_ERROR_MESSAGE
+/*
+ * Free an error string if necessary.  If we returned a static string, make
+ * sure we don't free it.
+ *
+ * This code assumes that the set of implementations that have
+ * krb5_free_error_message is a subset of those with krb5_get_error_message.
+ * If this assumption ever breaks, we may call the wrong free function.
+ */
+static void
+krb5_free_error_message(krb5_context ctx UNUSED, const char *msg)
+{
+    if (msg == error_unknown)
+        return;
+# if defined(HAVE_KRB5_GET_ERROR_STRING)
+    krb5_free_error_string(ctx, (char *) msg);
+# elif defined(HAVE_KRB5_SVC_GET_MSG)
+    krb5_free_string(ctx, (char *) msg);
+# endif
+}
+#endif /* !HAVE_KRB5_FREE_ERROR_MESSAGE */
+
+
+#ifndef HAVE_KRB5_GET_INIT_CREDS_OPT_ALLOC
+/*
+ * Allocate and initialize a krb5_get_init_creds_opt struct.  This code
+ * assumes that an all-zero bit pattern will create a NULL pointer.
+ */
+krb5_error_code
+krb5_get_init_creds_opt_alloc(krb5_context ctx, krb5_get_init_creds_opt **opts)
+{
+    *opts = calloc(1, sizeof(krb5_get_init_creds_opt));
+    if (*opts == NULL)
+        return errno;
+    krb5_get_init_creds_opt_init(*opts);
+    return 0;
+}
+#endif /* !HAVE_KRB5_GET_INIT_CREDS_OPT_ALLOC */