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git.ipfire.org Git - thirdparty/openssl.git/blob - crypto/punycode.c
2 * Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
12 #include <openssl/e_os2.h>
13 #include "crypto/punycode.h"
14 #include "internal/common.h" /* for HAS_PREFIX */
15 #include "internal/packet.h" /* for WPACKET */
17 static const unsigned int base
= 36;
18 static const unsigned int tmin
= 1;
19 static const unsigned int tmax
= 26;
20 static const unsigned int skew
= 38;
21 static const unsigned int damp
= 700;
22 static const unsigned int initial_bias
= 72;
23 static const unsigned int initial_n
= 0x80;
24 static const unsigned int maxint
= 0xFFFFFFFF;
25 static const char delimiter
= '-';
27 #define LABEL_BUF_SIZE 512
32 * function adapt(delta,numpoints,firsttime):
33 * if firsttime then let delta = delta div damp
34 * else let delta = delta div 2
35 * let delta = delta + (delta div numpoints)
37 * while delta > ((base - tmin) * tmax) div 2 do begin
38 * let delta = delta div (base - tmin)
41 * return k + (((base - tmin + 1) * delta) div (delta + skew))
44 static int adapt(unsigned int delta
, unsigned int numpoints
,
45 unsigned int firsttime
)
49 delta
= (firsttime
) ? delta
/ damp
: delta
/ 2;
50 delta
= delta
+ delta
/ numpoints
;
52 while (delta
> ((base
- tmin
) * tmax
) / 2) {
53 delta
= delta
/ (base
- tmin
);
57 return k
+ (((base
- tmin
+ 1) * delta
) / (delta
+ skew
));
60 static ossl_inline
int is_basic(unsigned int a
)
62 return (a
< 0x80) ? 1 : 0;
66 * code points digit-values
67 * ------------ ----------------------
68 * 41..5A (A-Z) = 0 to 25, respectively
69 * 61..7A (a-z) = 0 to 25, respectively
70 * 30..39 (0-9) = 26 to 35, respectively
72 static ossl_inline
int digit_decoded(const unsigned char a
)
74 if (a
>= 0x41 && a
<= 0x5A)
77 if (a
>= 0x61 && a
<= 0x7A)
80 if (a
>= 0x30 && a
<= 0x39)
89 * function ossl_punycode_decode
92 * let bias = initial_bias
93 * let output = an empty string indexed from 0
94 * consume all code points before the last delimiter (if there is one)
95 * and copy them to output, fail on any non-basic code point
96 * if more than zero code points were consumed then consume one more
97 * (which will be the last delimiter)
98 * while the input is not exhausted do begin
101 * for k = base to infinity in steps of base do begin
102 * consume a code point, or fail if there was none to consume
103 * let digit = the code point's digit-value, fail if it has none
104 * let i = i + digit * w, fail on overflow
105 * let t = tmin if k <= bias {+ tmin}, or
106 * tmax if k >= bias + tmax, or k - bias otherwise
107 * if digit < t then break
108 * let w = w * (base - t), fail on overflow
110 * let bias = adapt(i - oldi, length(output) + 1, test oldi is 0?)
111 * let n = n + i div (length(output) + 1), fail on overflow
112 * let i = i mod (length(output) + 1)
113 * {if n is a basic code point then fail}
114 * insert n into output at position i
119 int ossl_punycode_decode(const char *pEncoded
, const size_t enc_len
,
120 unsigned int *pDecoded
, unsigned int *pout_length
)
122 unsigned int n
= initial_n
;
124 unsigned int bias
= initial_bias
;
125 size_t processed_in
= 0, written_out
= 0;
126 unsigned int max_out
= *pout_length
;
127 unsigned int basic_count
= 0;
130 for (loop
= 0; loop
< enc_len
; loop
++) {
131 if (pEncoded
[loop
] == delimiter
)
135 if (basic_count
> 0) {
136 if (basic_count
> max_out
)
139 for (loop
= 0; loop
< basic_count
; loop
++) {
140 if (is_basic(pEncoded
[loop
]) == 0)
143 pDecoded
[loop
] = pEncoded
[loop
];
146 processed_in
= basic_count
+ 1;
149 for (loop
= processed_in
; loop
< enc_len
;) {
150 unsigned int oldi
= i
;
155 for (k
= base
;; k
+= base
) {
159 digit
= digit_decoded(pEncoded
[loop
]);
164 if ((unsigned int)digit
> (maxint
- i
) / w
)
168 t
= (k
<= bias
) ? tmin
: (k
>= bias
+ tmax
) ? tmax
: k
- bias
;
170 if ((unsigned int)digit
< t
)
173 if (w
> maxint
/ (base
- t
))
178 bias
= adapt(i
- oldi
, written_out
+ 1, (oldi
== 0));
179 if (i
/ (written_out
+ 1) > maxint
- n
)
181 n
= n
+ i
/ (written_out
+ 1);
182 i
%= (written_out
+ 1);
184 if (written_out
>= max_out
)
187 memmove(pDecoded
+ i
+ 1, pDecoded
+ i
,
188 (written_out
- i
) * sizeof(*pDecoded
));
194 *pout_length
= written_out
;
199 * Encode a code point using UTF-8
200 * return number of bytes on success, 0 on failure
201 * (also produces U+FFFD, which uses 3 bytes on failure)
203 static int codepoint2utf8(unsigned char *out
, unsigned long utf
)
207 out
[0] = (unsigned char)utf
;
210 } else if (utf
<= 0x07FF) {
212 out
[0] = (unsigned char)(((utf
>> 6) & 0x1F) | 0xC0);
213 out
[1] = (unsigned char)(((utf
>> 0) & 0x3F) | 0x80);
216 } else if (utf
<= 0xFFFF) {
218 out
[0] = (unsigned char)(((utf
>> 12) & 0x0F) | 0xE0);
219 out
[1] = (unsigned char)(((utf
>> 6) & 0x3F) | 0x80);
220 out
[2] = (unsigned char)(((utf
>> 0) & 0x3F) | 0x80);
223 } else if (utf
<= 0x10FFFF) {
225 out
[0] = (unsigned char)(((utf
>> 18) & 0x07) | 0xF0);
226 out
[1] = (unsigned char)(((utf
>> 12) & 0x3F) | 0x80);
227 out
[2] = (unsigned char)(((utf
>> 6) & 0x3F) | 0x80);
228 out
[3] = (unsigned char)(((utf
>> 0) & 0x3F) | 0x80);
232 /* error - use replacement character */
233 out
[0] = (unsigned char)0xEF;
234 out
[1] = (unsigned char)0xBF;
235 out
[2] = (unsigned char)0xBD;
244 * 0 - ok but buf was too short
245 * -1 - bad string passed or other error
248 int ossl_a2ulabel(const char *in
, char *out
, size_t outlen
)
251 * Domain name has some parts consisting of ASCII chars joined with dot.
252 * If a part is shorter than 5 chars, it becomes U-label as is.
253 * If it does not start with xn--, it becomes U-label as is.
254 * Otherwise we try to decode it.
256 const char *inptr
= in
;
259 unsigned int buf
[LABEL_BUF_SIZE
]; /* It's a hostname */
262 /* Internal API, so should not fail */
263 if (!ossl_assert(out
!= NULL
))
266 if (!WPACKET_init_static_len(&pkt
, (unsigned char *)out
, outlen
, 0))
270 char *tmpptr
= strchr(inptr
, '.');
271 size_t delta
= tmpptr
!= NULL
? (size_t)(tmpptr
- inptr
) : strlen(inptr
);
273 if (!HAS_PREFIX(inptr
, "xn--")) {
274 if (!WPACKET_memcpy(&pkt
, inptr
, delta
))
277 unsigned int bufsize
= LABEL_BUF_SIZE
;
279 if (ossl_punycode_decode(inptr
+ 4, delta
- 4, buf
, &bufsize
) <= 0) {
284 for (i
= 0; i
< bufsize
; i
++) {
285 unsigned char seed
[6];
286 size_t utfsize
= codepoint2utf8(seed
, buf
[i
]);
293 if (!WPACKET_memcpy(&pkt
, seed
, utfsize
))
301 if (!WPACKET_put_bytes_u8(&pkt
, '.'))
307 if (!WPACKET_put_bytes_u8(&pkt
, '\0'))
310 WPACKET_cleanup(&pkt
);