* Add krb5_c_init_state and krb5_c_free_state functions

* Add init_state and free_state to enc_providers as operations that need to be filled in
* Implement generic free_state and des-specific init_state
* Implement arcfour-specific init_state
* Add functions to find enctype state functions and call them
* Add tests for above

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@13948 dc483132-0cff-0310-8789-dd5450dbe970

1 files changed, 63 insertions, 0 deletions

diff --git a/src/lib/crypto/default_state.c b/src/lib/crypto/default_state.c
new file mode 100644
index 000000000..33a189f26
--- /dev/null
+++ b/src/lib/crypto/default_state.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2001 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.
+ * 
+ * Section 6 (Encryption) of the Kerberos revisions document defines
+ * cipher states to be used to chain encryptions and decryptions
+ * together.  Examples of cipher states include initialization vectors
+ * for CBC encription.  Most Kerberos encryption systems can share
+ * code for initializing and freeing cipher states.  This file
+ * contains that default code.
+ */
+
+#include "k5-int.h"
+
+krb5_error_code krb5int_des_init_state
+(const krb5_keyblock *key, krb5_keyusage usage, krb5_data *new_state )
+{
+  new_state->length = 8;
+  new_state->data = (void *) malloc(8);
+  if (new_state->data) {
+    memset (new_state->data, 0, new_state->length);
+    /* We need to copy in the key for des-cbc-cr--ick, but that's how it works*/
+    if (key->enctype == ENCTYPE_DES_CBC_CRC) {
+      memcpy (new_state->data, key->contents, new_state->length);
+  }
+  } else {
+    return ENOMEM;
+  }
+  return 0;
+}
+
+krb5_error_code krb5int_default_free_state
+(krb5_data *state)
+{
+  if (state->data) {
+    free (state->data);
+    state-> data = NULL;
+    state->length = 0;
+  }
+  return 0;
+}
+
+    
+