#ifndef lint
static char *rcsid = "$Id: punycode.c,v 1.1 2003/06/04 00:26:06 marka Exp $";
#endif
/*
* Copyright (c) 2001,2002 Japan Network Information Center.
* All rights reserved.
*
* By using this file, you agree to the terms and conditions set forth bellow.
*
* LICENSE TERMS AND CONDITIONS
*
* The following License Terms and Conditions apply, unless a different
* license is obtained from Japan Network Information Center ("JPNIC"),
* a Japanese association, Kokusai-Kougyou-Kanda Bldg 6F, 2-3-4 Uchi-Kanda,
* Chiyoda-ku, Tokyo 101-0047, Japan.
*
* 1. Use, Modification and Redistribution (including distribution of any
* modified or derived work) in source and/or binary forms is permitted
* under this License Terms and Conditions.
*
* 2. Redistribution of source code must retain the copyright notices as they
* appear in each source code file, this License Terms and Conditions.
*
* 3. Redistribution in binary form must reproduce the Copyright Notice,
* this License Terms and Conditions, in the documentation and/or other
* materials provided with the distribution. For the purposes of binary
* distribution the "Copyright Notice" refers to the following language:
* "Copyright (c) 2000-2002 Japan Network Information Center. All rights reserved."
*
* 4. The name of JPNIC may not be used to endorse or promote products
* derived from this Software without specific prior written approval of
* JPNIC.
*
* 5. Disclaimer/Limitation of Liability: THIS SOFTWARE IS PROVIDED BY JPNIC
* "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 JPNIC 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 DAMAGES.
*/
#include <config.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <idn/result.h>
#include <idn/assert.h>
#include <idn/logmacro.h>
#include <idn/converter.h>
#include <idn/ucs4.h>
#include <idn/debug.h>
#include <idn/punycode.h>
#include <idn/util.h>
/*
* Although draft-ietf-idn-punycode-00.txt doesn't specify the ACE
* signature, we have to choose one. In order to prevent the converted
* name from beginning with a hyphen, we should choose a prefix rather
* than a suffix.
*/
#ifndef IDN_PUNYCODE_PREFIX
#define IDN_PUNYCODE_PREFIX "xn--"
#endif
#define INVALID_UCS 0x80000000
#define MAX_UCS 0x10FFFF
/*
* As the draft states, it is possible that `delta' may overflow during
* the encoding. The upper bound of 'delta' is:
* <# of chars. of input string> + <max. difference in code point> *
* <# of chars. of input string + 1>
* For this value not to be greater than 0xffffffff (since the calculation
* is done using unsigned long, which is at least 32bit long), the maxmum
* input string size is about 3850 characters, which is long enough for
* a domain label...
*/
#define PUNYCODE_MAXINPUT 3800
/*
* Parameters.
*/
#define PUNYCODE_BASE 36
#define PUNYCODE_TMIN 1
#define PUNYCODE_TMAX 26
#define PUNYCODE_SKEW 38
#define PUNYCODE_DAMP 700
#define PUNYCODE_INITIAL_BIAS 72
#define PUNYCODE_INITIAL_N 0x80
static int punycode_getwc(const char *s, size_t len,
int bias, unsigned long *vp);
static int punycode_putwc(char *s, size_t len,
unsigned long delta, int bias);
static int punycode_update_bias(unsigned long delta,
size_t npoints, int first);
idn_result_t
idn__punycode_decode(idn_converter_t ctx, void *privdata,
const char *from, unsigned long *to, size_t tolen) {
unsigned long *to_org = to;
unsigned long c, idx;
size_t prefixlen = strlen(IDN_PUNYCODE_PREFIX);
size_t fromlen;
size_t uidx, fidx, ucslen;
int first, bias;
idn_result_t r;
assert(ctx != NULL);
TRACE(("idn__punycode_decode(from=\"%s\", tolen=%d)\n",
idn__debug_xstring(from, 50), (int)tolen));
if (!idn__util_asciihaveaceprefix(from, IDN_PUNYCODE_PREFIX)) {
if (*from == '\0') {
r = idn_ucs4_utf8toucs4(from, to, tolen);
goto ret;
}
r = idn_invalid_encoding;
goto ret;
}
from += prefixlen;
fromlen = strlen(from);
/*
* Find the last delimiter, and copy the characters
* before it verbatim.
*/
ucslen = 0;
for (fidx = fromlen; fidx > 0; fidx--) {
if (from[fidx - 1] == '-') {
if (tolen < fidx) {
r = idn_buffer_overflow;
goto ret;
}
for (uidx = 0; uidx < fidx - 1; uidx++) {
to[uidx] = from[uidx];
}
ucslen = uidx;
break;
}
}
first = 1;
bias = PUNYCODE_INITIAL_BIAS;
c = PUNYCODE_INITIAL_N;
idx = 0;
while (fidx < fromlen) {
int len;
unsigned long delta;
int i;
len = punycode_getwc(from + fidx, fromlen - fidx, bias, &delta);
if (len == 0) {
r = idn_invalid_encoding;
goto ret;
}
fidx += len;
bias = punycode_update_bias(delta, ucslen + 1, first);
first = 0;
idx += delta;
c += idx / (ucslen + 1);
uidx = idx % (ucslen + 1);
/* Insert 'c' at uidx. */
if (tolen-- <= 0) {
r = idn_buffer_overflow;
goto ret;
}
for (i = ucslen; i > uidx; i--)
to[i] = to[i - 1];
to[uidx] = c;
ucslen++;
idx = uidx + 1;
}
/* Terminate with NUL. */
if (tolen <= 0) {
r = idn_buffer_overflow;
goto ret;
}
to[ucslen] = '\0';
r = idn_success;
ret:
if (r == idn_success) {
TRACE(("idn__punycode_decode(): succcess (to=\"%s\")\n",
idn__debug_ucs4xstring(to_org, 50)));
} else {
TRACE(("idn__punycode_decode(): %s\n", idn_result_tostring(r)));
}
return (r);
}
idn_result_t
idn__punycode_encode(idn_converter_t ctx, void *privdata,
const unsigned long *from, char *to, size_t tolen) {
char *to_org = to;
unsigned long cur_code, next_code, delta;
size_t prefixlen = strlen(IDN_PUNYCODE_PREFIX);
size_t fromlen;
size_t ucsdone;
size_t toidx;
int uidx, bias, first;
idn_result_t r;
assert(ctx != NULL);
TRACE(("idn__punycode_encode(from=\"%s\", tolen=%d)\n",
idn__debug_ucs4xstring(from, 50), (int)tolen));
if (*from == '\0') {
r = idn_ucs4_ucs4toutf8(from, to, tolen);
goto ret;
} else if (idn__util_ucs4haveaceprefix(from, IDN_PUNYCODE_PREFIX)) {
r = idn_prohibited;
goto ret;
}
if (tolen < prefixlen) {
r = idn_buffer_overflow;
goto ret;
}
memcpy(to, IDN_PUNYCODE_PREFIX, prefixlen);
to += prefixlen;
tolen -= prefixlen;
fromlen = idn_ucs4_strlen(from);
/*
* If the input string is too long (actually too long to be sane),
* return failure in order to prevent possible overflow.
*/
if (fromlen > PUNYCODE_MAXINPUT) {
ERROR(("idn__punycode_encode(): "
"the input string is too long to convert Punycode\n",
idn__debug_ucs4xstring(from, 50)));
r = idn_failure;
goto ret;
}
ucsdone = 0; /* number of characters processed */
toidx = 0;
/*
* First, pick up basic code points and copy them to 'to'.
*/
for (uidx = 0; uidx < fromlen; uidx++) {
if (from[uidx] < 0x80) {
if (toidx >= tolen) {
r = idn_buffer_overflow;
goto ret;
}
to[toidx++] = from[uidx];
ucsdone++;
}
}
/*
* If there are any basic code points, output a delimiter
* (hyphen-minus).
*/
if (toidx > 0) {
if (toidx >= tolen) {
r = idn_buffer_overflow;
goto ret;
}
to[toidx++] = '-';
to += toidx;
tolen -= toidx;
}
/*
* Then encode non-basic characters.
*/
first = 1;
cur_code = PUNYCODE_INITIAL_N;
bias = PUNYCODE_INITIAL_BIAS;
delta = 0;
while (ucsdone < fromlen) {
int limit = -1, rest;
/*
* Find the smallest code point equal to or greater
* than 'cur_code'. Also remember the index of the
* last occurence of the code point.
*/
for (next_code = MAX_UCS, uidx = fromlen - 1;
uidx >= 0; uidx--) {
if (from[uidx] >= cur_code && from[uidx] < next_code) {
next_code = from[uidx];
limit = uidx;
}
}
/* There must be such code point. */
assert(limit >= 0);
delta += (next_code - cur_code) * (ucsdone + 1);
cur_code = next_code;
/*
* Scan the input string again, and encode characters
* whose code point is 'cur_code'. Use 'limit' to avoid
* unnecessary scan.
*/
for (uidx = 0, rest = ucsdone; uidx <= limit; uidx++) {
if (from[uidx] < cur_code) {
delta++;
rest--;
} else if (from[uidx] == cur_code) {
int sz = punycode_putwc(to, tolen, delta, bias);
if (sz == 0) {
r = idn_buffer_overflow;
goto ret;
}
to += sz;
tolen -= sz;
ucsdone++;
bias = punycode_update_bias(delta, ucsdone,
first);
delta = 0;
first = 0;
}
}
delta += rest + 1;
cur_code++;
}
/*
* Terminate with NUL.
*/
if (tolen <= 0) {
r = idn_buffer_overflow;
goto ret;
}
*to = '\0';
r = idn_success;
ret:
if (r == idn_success) {
TRACE(("idn__punycode_encode(): succcess (to=\"%s\")\n",
idn__debug_xstring(to_org, 50)));
} else {
TRACE(("idn__punycode_encode(): %s\n", idn_result_tostring(r)));
}
return (r);
}
static int
punycode_getwc(const char *s, size_t len, int bias, unsigned long *vp) {
size_t orglen = len;
unsigned long v = 0, w = 1;
int k;
for (k = PUNYCODE_BASE - bias; len > 0; k += PUNYCODE_BASE) {
int c = *s++;
int t = (k < PUNYCODE_TMIN) ? PUNYCODE_TMIN :
(k > PUNYCODE_TMAX) ? PUNYCODE_TMAX : k;
len--;
if ('a' <= c && c <= 'z')
c = c - 'a';
else if ('A' <= c && c <= 'Z')
c = c - 'A';
else if ('0' <= c && c <= '9')
c = c - '0' + 26;
else
c = -1;
if (c < 0)
return (0); /* invalid character */
v += c * w;
if (c < t) {
*vp = v;
return (orglen - len);
}
w *= (PUNYCODE_BASE - t);
}
return (0); /* final character missing */
}
static int
punycode_putwc(char *s, size_t len, unsigned long delta, int bias) {
const char *punycode_base36 = "abcdefghijklmnopqrstuvwxyz0123456789";
int k;
char *sorg = s;
for (k = PUNYCODE_BASE - bias; 1; k += PUNYCODE_BASE) {
int t = (k < PUNYCODE_TMIN) ? PUNYCODE_TMIN :
(k > PUNYCODE_TMAX) ? PUNYCODE_TMAX : k;
if (delta < t)
break;
if (len < 1)
return (0);
*s++ = punycode_base36[t + ((delta - t) % (PUNYCODE_BASE - t))];
len--;
delta = (delta - t) / (PUNYCODE_BASE - t);
}
if (len < 1)
return (0);
*s++ = punycode_base36[delta];
return (s - sorg);
}
static int
punycode_update_bias(unsigned long delta, size_t npoints, int first) {
int k = 0;
delta /= first ? PUNYCODE_DAMP : 2;
delta += delta / npoints;
while (delta > ((PUNYCODE_BASE - PUNYCODE_TMIN) * PUNYCODE_TMAX) / 2) {
delta /= PUNYCODE_BASE - PUNYCODE_TMIN;
k++;
}
return (PUNYCODE_BASE * k +
(((PUNYCODE_BASE - PUNYCODE_TMIN + 1) * delta) /
(delta + PUNYCODE_SKEW)));
}