From 954c01728e0c7485b72c9a5d5737e5f6bd0cf0b9 Mon Sep 17 00:00:00 2001
From: Heimdal Import User <samba-bugs@samba.org>
Date: Mon, 11 Jul 2005 01:16:55 +0000
Subject: r8302: import mini HEIMDAL into the tree (This used to be commit
 118be28a7aef233799956615a99d1a2a74dac175)

---
 source4/heimdal/lib/krb5/n-fold.c | 126 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 126 insertions(+)
 create mode 100644 source4/heimdal/lib/krb5/n-fold.c

(limited to 'source4/heimdal/lib/krb5/n-fold.c')

diff --git a/source4/heimdal/lib/krb5/n-fold.c b/source4/heimdal/lib/krb5/n-fold.c
new file mode 100644
index 0000000000..691e95eb86
--- /dev/null
+++ b/source4/heimdal/lib/krb5/n-fold.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 1999 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden). 
+ * All rights reserved. 
+ *
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions 
+ * are met: 
+ *
+ * 1. Redistributions of source code must retain the above copyright 
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. 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. 
+ *
+ * 3. Neither the name of KTH nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software without
+ *    specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY KTH AND ITS 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 KTH OR ITS 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 "krb5_locl.h"
+
+RCSID("$Id: n-fold.c,v 1.7 2004/05/25 21:35:31 lha Exp $");
+
+static void
+rr13(unsigned char *buf, size_t len)
+{
+    unsigned char *tmp;
+    int bytes = (len + 7) / 8;
+    int i;
+    if(len == 0)
+	return;
+    {
+	const int bits = 13 % len;
+	const int lbit = len % 8;
+    
+	tmp = malloc(bytes);
+	memcpy(tmp, buf, bytes);
+	if(lbit) {
+	    /* pad final byte with inital bits */
+	    tmp[bytes - 1] &= 0xff << (8 - lbit);
+	    for(i = lbit; i < 8; i += len)
+		tmp[bytes - 1] |= buf[0] >> i;
+	}
+	for(i = 0; i < bytes; i++) {
+	    int bb;
+	    int b1, s1, b2, s2;
+	    /* calculate first bit position of this byte */
+	    bb = 8 * i - bits;
+	    while(bb < 0)
+		bb += len;
+	    /* byte offset and shift count */
+	    b1 = bb / 8;
+	    s1 = bb % 8;
+	
+	    if(bb + 8 > bytes * 8) 
+		/* watch for wraparound */
+		s2 = (len + 8 - s1) % 8;
+	    else 
+		s2 = 8 - s1;
+	    b2 = (b1 + 1) % bytes;
+	    buf[i] = (tmp[b1] << s1) | (tmp[b2] >> s2);
+	}
+	free(tmp);
+    }
+}
+
+/* Add `b' to `a', both beeing one's complement numbers. */
+static void
+add1(unsigned char *a, unsigned char *b, size_t len)
+{
+    int i;
+    int carry = 0;
+    for(i = len - 1; i >= 0; i--){
+	int x = a[i] + b[i] + carry;
+	carry = x > 0xff;
+	a[i] = x & 0xff;
+    }
+    for(i = len - 1; carry && i >= 0; i--){
+	int x = a[i] + carry;
+	carry = x > 0xff;
+	a[i] = x & 0xff;
+    }
+}
+
+void KRB5_LIB_FUNCTION
+_krb5_n_fold(const void *str, size_t len, void *key, size_t size)
+{
+    /* if len < size we need at most N * len bytes, ie < 2 * size;
+       if len > size we need at most 2 * len */
+    size_t maxlen = 2 * max(size, len);
+    size_t l = 0;
+    unsigned char *tmp = malloc(maxlen);
+    unsigned char *buf = malloc(len);
+    
+    memcpy(buf, str, len);
+    memset(key, 0, size);
+    do {
+	memcpy(tmp + l, buf, len);
+	l += len;
+	rr13(buf, len * 8);
+	while(l >= size) {
+	    add1(key, tmp, size);
+	    l -= size;
+	    if(l == 0)
+		break;
+	    memmove(tmp, tmp + size, l);
+	}
+    } while(l != 0);
+    memset(buf, 0, len);
+    free(buf);
+    memset(tmp, 0, maxlen);
+    free(tmp);
+}
-- 
cgit