Factor out krb5int_random_string() routine

Make krb5int_random_string() function available outside ccache code.
Move it into a separate file under lib/krb5/krb hierarchy.

1 files changed, 68 insertions, 0 deletions

diff --git a/src/lib/krb5/krb/random_str.c b/src/lib/krb5/krb/random_str.c
new file mode 100644
index 0000000000..e31430ccac
--- /dev/null
+++ b/src/lib/krb5/krb/random_str.c
@@ -0,0 +1,68 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/* lib/krb5/krb/random_str.c - Definition of krb5int_random_string() */
+/*
+ * Copyright (C) 2013 by the Massachusetts Institute of Technology.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in
+ *   the documentation and/or other materials provided with the
+ *   distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "k5-int.h"
+
+/* Utility routine: Creates a readable random string in a fixed size buffer. */
+krb5_error_code
+krb5int_random_string(krb5_context context, char *string, unsigned int length)
+{
+    static const unsigned char charlist[] =
+        "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    krb5_error_code err = 0;
+    unsigned char *bytes = NULL;
+    unsigned int bytecount = length - 1;
+
+    if (!err) {
+        bytes = malloc (bytecount);
+        if (bytes == NULL) { err = ENOMEM; }
+    }
+
+    if (!err) {
+        krb5_data data;
+        data.length = bytecount;
+        data.data = (char *) bytes;
+        err = krb5_c_random_make_octets (context, &data);
+    }
+
+    if (!err) {
+        unsigned int i;
+        for (i = 0; i < bytecount; i++) {
+            string [i] = charlist[bytes[i] % (sizeof (charlist) - 1)];
+        }
+        string[length - 1] = '\0';
+    }
+
+    if (bytes != NULL) { free (bytes); }
+
+    return err;
+}