libwind from Assar. stringprep library supporting nameprep, saslprep and ldapprep

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@22551 ec53bebd-3082-4978-b11e-865c3cabbd6b

lib/wind/punycode.c

@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 2004 Kungliga Tekniska H<>gskolan
+ * (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 the Institute 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 THE INSTITUTE 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 INSTITUTE 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. 
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include "windlocl.h"
+
+RCSID("$Id$");
+
+static const unsigned base         = 36;
+static const unsigned t_min        = 1;
+static const unsigned t_max        = 26;
+static const unsigned skew         = 38;
+static const unsigned damp         = 700;
+static const unsigned initial_n    = 128;
+static const unsigned initial_bias = 72;
+
+static unsigned
+digit(unsigned n)
+{
+    return "abcdefghijklmnopqrstuvwxyz0123456789"[n];
+}
+
+static unsigned
+adapt(unsigned delta, unsigned numpoints, int first)
+{
+    unsigned k;
+
+    if (first)
+	delta = delta / damp;
+    else
+	delta /= 2;
+    delta += delta / numpoints;
+    k = 0;
+    while (delta > ((base - t_min) * t_max) / 2) {
+	delta /= base - t_min;
+	k += base;
+    }
+    return k + (((base - t_min + 1) * delta) / (delta + skew));
+}
+
+int
+wind_punycode_toascii(const uint32_t *in, size_t in_len,
+		      char *out, size_t *out_len)
+{
+    unsigned n     = initial_n;
+    unsigned delta = 0;
+    unsigned bias  = initial_bias;
+    unsigned h = 0;
+    unsigned b;
+    unsigned i;
+    unsigned o = 0;
+    unsigned m;
+    int ret = 0;
+
+    for (i = 0; i < in_len; ++i) {
+	if (in[i] < 0x80) {
+	    ++h;
+	    if (o >= *out_len)
+		return -1;
+	    out[o++] = in[i];
+	}
+    }
+    b = h;
+    if (b > 0) {
+	if (o >= *out_len)
+	    return -1;
+	out[o++] = 0x2D;
+    }
+    while (h < in_len) {
+	ret = 1;
+	m = (unsigned)-1;
+	for (i = 0; i < in_len; ++i)
+	    if(in[i] < m && in[i] >= n)
+		m = in[i];
+
+	delta += (m - n) * (h + 1);
+	n = m;
+	for (i = 0; i < in_len; ++i) {
+	    if (in[i] < n) {
+		++delta;
+	    } else if (in[i] == n) {
+		unsigned q = delta;
+		unsigned k;
+		for (k = base; ; k += base) {
+		    unsigned t;
+		    if (k <= bias)
+			t = t_min;
+		    else if (k >= bias + t_max)
+			t = t_max;
+		    else
+			t = k - bias;
+		    if (q < t)
+			break;
+		    if (o >= *out_len)
+			return -1;
+		    out[o++] = digit(t + ((q - t) % (base - t)));
+		    q = (q - t) / (base - t);
+		}
+		if (o >= *out_len)
+		    return -1;
+		out[o++] = digit(q);
+		/* output */
+		bias = adapt(delta, h + 1, h == b);
+		delta = 0;
+		++h;
+	    }
+	}
+	++delta;
+	++n;
+    }
+
+    *out_len = o;
+    return ret;
+}