diff options
Diffstat (limited to 'contrib/librdns/punycode.c')
-rw-r--r-- | contrib/librdns/punycode.c | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/contrib/librdns/punycode.c b/contrib/librdns/punycode.c new file mode 100644 index 0000000..61091b2 --- /dev/null +++ b/contrib/librdns/punycode.c @@ -0,0 +1,303 @@ +/* + * Copyright (c) 2014, Vsevolod Stakhov + * Copyright (c) 2004, 2006, 2007, 2008 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. + */ + +#include "dns_private.h" +static const unsigned event_loop = 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; +/* Punycode utility */ +static unsigned int +digit (unsigned n) +{ + static const char ascii[] = "abcdefghijklmnopqrstuvwxyz0123456789"; + return ascii[n]; +} + +static unsigned int +adapt (unsigned int delta, unsigned int numpoints, int first) +{ + unsigned int k; + + if (first) { + delta = delta / damp; + } + else { + delta /= 2; + } + delta += delta / numpoints; + k = 0; + while (delta > ((event_loop - t_min) * t_max) / 2) { + delta /= event_loop - t_min; + k += event_loop; + } + return k + (((event_loop - 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 NULL + * terminated. + * @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 + */ + +bool +rdns_punycode_label_toascii (const uint32_t *in, size_t in_len, char *out, + size_t *out_len) +{ + unsigned int n = initial_n; + unsigned int delta = 0; + unsigned int bias = initial_bias; + unsigned int h = 0; + unsigned int b; + unsigned int i; + unsigned int o = 0; + unsigned int m; + + for (i = 0; i < in_len; ++i) { + if (in[i] < 0x80) { + ++h; + if (o >= *out_len) { + return false; + } + out[o++] = in[i]; + } + } + b = h; + if (b > 0) { + if (o >= *out_len) { + return false; + } + out[o++] = 0x2D; + } + /* is this string punycoded */ + if (h < in_len) { + if (o + 4 >= *out_len) { + return false; + } + memmove (out + 4, out, o); + memcpy (out, "xn--", 4); + o += 4; + } + + while (h < in_len) { + m = (unsigned int) -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 int q = delta; + unsigned int k; + for (k = event_loop;; k += event_loop) { + unsigned int 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) % (event_loop - t))); + q = (q - t) / (event_loop - 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 true; +} + +static int +utf8toutf32 (const unsigned char **pp, uint32_t *out, size_t *remain) +{ + const unsigned char *p = *pp; + unsigned c = *p; + size_t reduce; + + if (c & 0x80) { + if ((c & 0xE0) == 0xC0 && *remain >= 2) { + const unsigned c2 = *++p; + reduce = 2; + if ((c2 & 0xC0) == 0x80) { + *out = ((c & 0x1F) << 6) | (c2 & 0x3F); + } + else { + return -1; + } + } + else if ((c & 0xF0) == 0xE0 && *remain >= 3) { + const unsigned c2 = *++p; + if ((c2 & 0xC0) == 0x80) { + const unsigned c3 = *++p; + reduce = 3; + if ((c3 & 0xC0) == 0x80) { + *out = ((c & 0x0F) << 12) | ((c2 & 0x3F) << 6) + | (c3 & 0x3F); + } + else { + return -1; + } + } + else { + return -1; + } + } + else if ((c & 0xF8) == 0xF0 && *remain >= 4) { + const unsigned c2 = *++p; + if ((c2 & 0xC0) == 0x80) { + const unsigned c3 = *++p; + if ((c3 & 0xC0) == 0x80) { + const unsigned c4 = *++p; + reduce = 4; + if ((c4 & 0xC0) == 0x80) { + *out = ((c & 0x07) << 18) | ((c2 & 0x3F) << 12) + | ((c3 & 0x3F) << 6) | (c4 & 0x3F); + } + else { + return -1; + } + } + else { + return -1; + } + } + else { + return -1; + } + } + else { + return -1; + } + } + else { + *out = c; + reduce = 1; + } + + *pp = ++p; + *remain -= reduce; + + return 0; +} + +/** + * Convert an UTF-8 string to an UCS4 string. + * + * @param in an UTF-8 string to convert. + * @param out the resulting UCS4 string + * @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 -1 otherwise + * @ingroup wind + */ + +int +rdns_utf8_to_ucs4 (const char *in, size_t in_len, uint32_t **out, size_t *out_len) +{ + const unsigned char *p; + size_t remain = in_len, olen = 0; + int ret; + uint32_t *res; + + p = (const unsigned char *)in; + while (remain > 0) { + uint32_t u; + + ret = utf8toutf32 (&p, &u, &remain); + if (ret != 0) { + return ret; + } + + olen ++; + } + res = malloc (olen * sizeof (uint32_t)); + if (res == NULL) { + return -1; + } + + p = (const unsigned char *)in; + remain = in_len; + olen = 0; + while (remain > 0) { + uint32_t u; + + (void)utf8toutf32 (&p, &u, &remain); + res[olen++] = u; + } + + *out_len = olen; + *out = res; + return 0; +} |