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/*
* Copyright (c) 2004 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 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 <string.h>
#include "windlocl.h"
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));
}
/**
* Convert an UCS4 string to a puny-coded DNS label string suitable
* when combined with delimiters and other labels for DNS lookup.
*
* @param in an UCS4 string to convert
* @param in_len the length of in.
* @param out the resulting puny-coded string. The string is not NUL
* terminatied.
* @param out_len before processing out_len should be the length of
* the out variable, after processing it will be the length of the out
* string.
*
* @return returns 0 on success, an wind error code otherwise
* @ingroup wind
*/
int
wind_punycode_label_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;
for (i = 0; i < in_len; ++i) {
if (in[i] < 0x80) {
++h;
if (o >= *out_len)
return WIND_ERR_OVERRUN;
out[o++] = in[i];
}
}
b = h;
if (b > 0) {
if (o >= *out_len)
return WIND_ERR_OVERRUN;
out[o++] = 0x2D;
}
/* is this string punycoded */
if (h < in_len) {
if (o + 4 >= *out_len)
return WIND_ERR_OVERRUN;
memmove(out + 4, out, o);
memcpy(out, "xn--", 4);
o += 4;
}
while (h < in_len) {
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 WIND_ERR_OVERRUN;
out[o++] = digit(t + ((q - t) % (base - t)));
q = (q - t) / (base - t);
}
if (o >= *out_len)
return WIND_ERR_OVERRUN;
out[o++] = digit(q);
/* output */
bias = adapt(delta, h + 1, h == b);
delta = 0;
++h;
}
}
++delta;
++n;
}
*out_len = o;
return 0;
}
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