1 files changed, 75 insertions, 0 deletions
diff --git a/src/lib/krb5/krb/gen_subkey.c b/src/lib/krb5/krb/gen_subkey.c
new file mode 100644
index 0000000000000..45f7b18e7a7fc
--- /dev/null
+++ b/src/lib/krb5/krb/gen_subkey.c
@@ -0,0 +1,75 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/* lib/krb5/krb/gen_subkey.c - Generate a subsession key based on input key */
+/*
+ * Copyright 1991, 2002 by the Massachusetts Institute of Technology.
+ * All Rights Reserved.
+ *
+ * Export of this software from the United States of America may
+ *   require a specific license from the United States Government.
+ *   It is the responsibility of any person or organization contemplating
+ *   export to obtain such a license before exporting.
+ *
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of M.I.T. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  Furthermore if you modify this software you must label
+ * your software as modified software and not distribute it in such a
+ * fashion that it might be confused with the original M.I.T. software.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ */
+
+#include "k5-int.h"
+
+static inline krb5_data
+key2data (krb5_keyblock k)
+{
+    krb5_data d;
+    d.magic = KV5M_DATA;
+    d.length = k.length;
+    d.data = (char *) k.contents;
+    return d;
+}
+
+krb5_error_code
+krb5_generate_subkey_extended(krb5_context context,
+                              const krb5_keyblock *key,
+                              krb5_enctype enctype,
+                              krb5_keyblock **subkey)
+{
+    krb5_error_code retval;
+    krb5_data seed;
+    krb5_keyblock *keyblock;
+
+    *subkey = NULL;
+
+    seed = key2data(*key);
+    retval = krb5_c_random_add_entropy(context, KRB5_C_RANDSOURCE_TRUSTEDPARTY,
+                                       &seed);
+    if (retval)
+        return retval;
+
+    keyblock = malloc(sizeof(krb5_keyblock));
+    if (!keyblock)
+        return ENOMEM;
+
+    retval = krb5_c_make_random_key(context, enctype, keyblock);
+    if (retval) {
+        free(*subkey);
+        return retval;
+    }
+
+    *subkey = keyblock;
+    return 0;
+}
+
+krb5_error_code
+krb5_generate_subkey(krb5_context context, const krb5_keyblock *key, krb5_keyblock **subkey)
+{
+    return krb5_generate_subkey_extended(context, key, key->enctype, subkey);
+}