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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 *******************************************************************************
5 *   Copyright (C) 2010-2015, International Business Machines
6 *   Corporation and others.  All Rights Reserved.
7 *******************************************************************************
8 *   file name:  uts46.cpp
9 *   encoding:   UTF-8
10 *   tab size:   8 (not used)
11 *   indentation:4
12 *
13 *   created on: 2010mar09
14 *   created by: Markus W. Scherer
15 */
16 
17 #include "unicode/utypes.h"
18 
19 #if !UCONFIG_NO_IDNA
20 
21 #include "unicode/idna.h"
22 #include "unicode/normalizer2.h"
23 #include "unicode/uscript.h"
24 #include "unicode/ustring.h"
25 #include "unicode/utf16.h"
26 #include "cmemory.h"
27 #include "cstring.h"
28 #include "punycode.h"
29 #include "ubidi_props.h"
30 #include "ustr_imp.h"
31 
32 // Note about tests for UIDNA_ERROR_DOMAIN_NAME_TOO_LONG:
33 //
34 // The domain name length limit is 255 octets in an internal DNS representation
35 // where the last ("root") label is the empty label
36 // represented by length byte 0 alone.
37 // In a conventional string, this translates to 253 characters, or 254
38 // if there is a trailing dot for the root label.
39 
40 U_NAMESPACE_BEGIN
41 
42 // Severe errors which usually result in a U+FFFD replacement character in the result string.
43 const uint32_t severeErrors=
44     UIDNA_ERROR_LEADING_COMBINING_MARK|
45     UIDNA_ERROR_DISALLOWED|
46     UIDNA_ERROR_PUNYCODE|
47     UIDNA_ERROR_LABEL_HAS_DOT|
48     UIDNA_ERROR_INVALID_ACE_LABEL;
49 
50 static inline UBool
isASCIIString(const UnicodeString & dest)51 isASCIIString(const UnicodeString &dest) {
52     const UChar *s=dest.getBuffer();
53     const UChar *limit=s+dest.length();
54     while(s<limit) {
55         if(*s++>0x7f) {
56             return FALSE;
57         }
58     }
59     return TRUE;
60 }
61 
62 static UBool
63 isASCIIOkBiDi(const UChar *s, int32_t length);
64 
65 static UBool
66 isASCIIOkBiDi(const char *s, int32_t length);
67 
68 // IDNA class default implementations -------------------------------------- ***
69 
~IDNA()70 IDNA::~IDNA() {}
71 
72 void
labelToASCII_UTF8(StringPiece label,ByteSink & dest,IDNAInfo & info,UErrorCode & errorCode) const73 IDNA::labelToASCII_UTF8(StringPiece label, ByteSink &dest,
74                         IDNAInfo &info, UErrorCode &errorCode) const {
75     if(U_SUCCESS(errorCode)) {
76         UnicodeString destString;
77         labelToASCII(UnicodeString::fromUTF8(label), destString,
78                      info, errorCode).toUTF8(dest);
79     }
80 }
81 
82 void
labelToUnicodeUTF8(StringPiece label,ByteSink & dest,IDNAInfo & info,UErrorCode & errorCode) const83 IDNA::labelToUnicodeUTF8(StringPiece label, ByteSink &dest,
84                          IDNAInfo &info, UErrorCode &errorCode) const {
85     if(U_SUCCESS(errorCode)) {
86         UnicodeString destString;
87         labelToUnicode(UnicodeString::fromUTF8(label), destString,
88                        info, errorCode).toUTF8(dest);
89     }
90 }
91 
92 void
nameToASCII_UTF8(StringPiece name,ByteSink & dest,IDNAInfo & info,UErrorCode & errorCode) const93 IDNA::nameToASCII_UTF8(StringPiece name, ByteSink &dest,
94                        IDNAInfo &info, UErrorCode &errorCode) const {
95     if(U_SUCCESS(errorCode)) {
96         UnicodeString destString;
97         nameToASCII(UnicodeString::fromUTF8(name), destString,
98                     info, errorCode).toUTF8(dest);
99     }
100 }
101 
102 void
nameToUnicodeUTF8(StringPiece name,ByteSink & dest,IDNAInfo & info,UErrorCode & errorCode) const103 IDNA::nameToUnicodeUTF8(StringPiece name, ByteSink &dest,
104                         IDNAInfo &info, UErrorCode &errorCode) const {
105     if(U_SUCCESS(errorCode)) {
106         UnicodeString destString;
107         nameToUnicode(UnicodeString::fromUTF8(name), destString,
108                       info, errorCode).toUTF8(dest);
109     }
110 }
111 
112 // UTS46 class declaration ------------------------------------------------- ***
113 
114 class UTS46 : public IDNA {
115 public:
116     UTS46(uint32_t options, UErrorCode &errorCode);
117     virtual ~UTS46();
118 
119     virtual UnicodeString &
120     labelToASCII(const UnicodeString &label, UnicodeString &dest,
121                  IDNAInfo &info, UErrorCode &errorCode) const;
122 
123     virtual UnicodeString &
124     labelToUnicode(const UnicodeString &label, UnicodeString &dest,
125                    IDNAInfo &info, UErrorCode &errorCode) const;
126 
127     virtual UnicodeString &
128     nameToASCII(const UnicodeString &name, UnicodeString &dest,
129                 IDNAInfo &info, UErrorCode &errorCode) const;
130 
131     virtual UnicodeString &
132     nameToUnicode(const UnicodeString &name, UnicodeString &dest,
133                   IDNAInfo &info, UErrorCode &errorCode) const;
134 
135     virtual void
136     labelToASCII_UTF8(StringPiece label, ByteSink &dest,
137                       IDNAInfo &info, UErrorCode &errorCode) const;
138 
139     virtual void
140     labelToUnicodeUTF8(StringPiece label, ByteSink &dest,
141                        IDNAInfo &info, UErrorCode &errorCode) const;
142 
143     virtual void
144     nameToASCII_UTF8(StringPiece name, ByteSink &dest,
145                      IDNAInfo &info, UErrorCode &errorCode) const;
146 
147     virtual void
148     nameToUnicodeUTF8(StringPiece name, ByteSink &dest,
149                       IDNAInfo &info, UErrorCode &errorCode) const;
150 
151 private:
152     UnicodeString &
153     process(const UnicodeString &src,
154             UBool isLabel, UBool toASCII,
155             UnicodeString &dest,
156             IDNAInfo &info, UErrorCode &errorCode) const;
157 
158     void
159     processUTF8(StringPiece src,
160                 UBool isLabel, UBool toASCII,
161                 ByteSink &dest,
162                 IDNAInfo &info, UErrorCode &errorCode) const;
163 
164     UnicodeString &
165     processUnicode(const UnicodeString &src,
166                    int32_t labelStart, int32_t mappingStart,
167                    UBool isLabel, UBool toASCII,
168                    UnicodeString &dest,
169                    IDNAInfo &info, UErrorCode &errorCode) const;
170 
171     // returns the new dest.length()
172     int32_t
173     mapDevChars(UnicodeString &dest, int32_t labelStart, int32_t mappingStart,
174                 UErrorCode &errorCode) const;
175 
176     // returns the new label length
177     int32_t
178     processLabel(UnicodeString &dest,
179                  int32_t labelStart, int32_t labelLength,
180                  UBool toASCII,
181                  IDNAInfo &info, UErrorCode &errorCode) const;
182     int32_t
183     markBadACELabel(UnicodeString &dest,
184                     int32_t labelStart, int32_t labelLength,
185                     UBool toASCII, IDNAInfo &info, UErrorCode &errorCode) const;
186 
187     void
188     checkLabelBiDi(const UChar *label, int32_t labelLength, IDNAInfo &info) const;
189 
190     UBool
191     isLabelOkContextJ(const UChar *label, int32_t labelLength) const;
192 
193     void
194     checkLabelContextO(const UChar *label, int32_t labelLength, IDNAInfo &info) const;
195 
196     const Normalizer2 &uts46Norm2;  // uts46.nrm
197     uint32_t options;
198 };
199 
200 IDNA *
createUTS46Instance(uint32_t options,UErrorCode & errorCode)201 IDNA::createUTS46Instance(uint32_t options, UErrorCode &errorCode) {
202     if(U_SUCCESS(errorCode)) {
203         IDNA *idna=new UTS46(options, errorCode);
204         if(idna==NULL) {
205             errorCode=U_MEMORY_ALLOCATION_ERROR;
206         } else if(U_FAILURE(errorCode)) {
207             delete idna;
208             idna=NULL;
209         }
210         return idna;
211     } else {
212         return NULL;
213     }
214 }
215 
216 // UTS46 implementation ---------------------------------------------------- ***
217 
UTS46(uint32_t opt,UErrorCode & errorCode)218 UTS46::UTS46(uint32_t opt, UErrorCode &errorCode)
219         : uts46Norm2(*Normalizer2::getInstance(NULL, "uts46", UNORM2_COMPOSE, errorCode)),
220           options(opt) {}
221 
~UTS46()222 UTS46::~UTS46() {}
223 
224 UnicodeString &
labelToASCII(const UnicodeString & label,UnicodeString & dest,IDNAInfo & info,UErrorCode & errorCode) const225 UTS46::labelToASCII(const UnicodeString &label, UnicodeString &dest,
226                     IDNAInfo &info, UErrorCode &errorCode) const {
227     return process(label, TRUE, TRUE, dest, info, errorCode);
228 }
229 
230 UnicodeString &
labelToUnicode(const UnicodeString & label,UnicodeString & dest,IDNAInfo & info,UErrorCode & errorCode) const231 UTS46::labelToUnicode(const UnicodeString &label, UnicodeString &dest,
232                       IDNAInfo &info, UErrorCode &errorCode) const {
233     return process(label, TRUE, FALSE, dest, info, errorCode);
234 }
235 
236 UnicodeString &
nameToASCII(const UnicodeString & name,UnicodeString & dest,IDNAInfo & info,UErrorCode & errorCode) const237 UTS46::nameToASCII(const UnicodeString &name, UnicodeString &dest,
238                    IDNAInfo &info, UErrorCode &errorCode) const {
239     process(name, FALSE, TRUE, dest, info, errorCode);
240     if( dest.length()>=254 && (info.errors&UIDNA_ERROR_DOMAIN_NAME_TOO_LONG)==0 &&
241         isASCIIString(dest) &&
242         (dest.length()>254 || dest[253]!=0x2e)
243     ) {
244         info.errors|=UIDNA_ERROR_DOMAIN_NAME_TOO_LONG;
245     }
246     return dest;
247 }
248 
249 UnicodeString &
nameToUnicode(const UnicodeString & name,UnicodeString & dest,IDNAInfo & info,UErrorCode & errorCode) const250 UTS46::nameToUnicode(const UnicodeString &name, UnicodeString &dest,
251                      IDNAInfo &info, UErrorCode &errorCode) const {
252     return process(name, FALSE, FALSE, dest, info, errorCode);
253 }
254 
255 void
labelToASCII_UTF8(StringPiece label,ByteSink & dest,IDNAInfo & info,UErrorCode & errorCode) const256 UTS46::labelToASCII_UTF8(StringPiece label, ByteSink &dest,
257                          IDNAInfo &info, UErrorCode &errorCode) const {
258     processUTF8(label, TRUE, TRUE, dest, info, errorCode);
259 }
260 
261 void
labelToUnicodeUTF8(StringPiece label,ByteSink & dest,IDNAInfo & info,UErrorCode & errorCode) const262 UTS46::labelToUnicodeUTF8(StringPiece label, ByteSink &dest,
263                           IDNAInfo &info, UErrorCode &errorCode) const {
264     processUTF8(label, TRUE, FALSE, dest, info, errorCode);
265 }
266 
267 void
nameToASCII_UTF8(StringPiece name,ByteSink & dest,IDNAInfo & info,UErrorCode & errorCode) const268 UTS46::nameToASCII_UTF8(StringPiece name, ByteSink &dest,
269                         IDNAInfo &info, UErrorCode &errorCode) const {
270     processUTF8(name, FALSE, TRUE, dest, info, errorCode);
271 }
272 
273 void
nameToUnicodeUTF8(StringPiece name,ByteSink & dest,IDNAInfo & info,UErrorCode & errorCode) const274 UTS46::nameToUnicodeUTF8(StringPiece name, ByteSink &dest,
275                          IDNAInfo &info, UErrorCode &errorCode) const {
276     processUTF8(name, FALSE, FALSE, dest, info, errorCode);
277 }
278 
279 // UTS #46 data for ASCII characters.
280 // The normalizer (using uts46.nrm) maps uppercase ASCII letters to lowercase
281 // and passes through all other ASCII characters.
282 // If UIDNA_USE_STD3_RULES is set, then non-LDH characters are disallowed
283 // using this data.
284 // The ASCII fastpath also uses this data.
285 // Values: -1=disallowed  0==valid  1==mapped (lowercase)
286 static const int8_t asciiData[128]={
287     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
288     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
289     // 002D..002E; valid  #  HYPHEN-MINUS..FULL STOP
290     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  0,  0, -1,
291     // 0030..0039; valid  #  DIGIT ZERO..DIGIT NINE
292      0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -1, -1, -1, -1, -1, -1,
293     // 0041..005A; mapped  #  LATIN CAPITAL LETTER A..LATIN CAPITAL LETTER Z
294     -1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
295      1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1,
296     // 0061..007A; valid  #  LATIN SMALL LETTER A..LATIN SMALL LETTER Z
297     -1,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
298      0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, -1, -1, -1, -1, -1
299 };
300 
301 UnicodeString &
process(const UnicodeString & src,UBool isLabel,UBool toASCII,UnicodeString & dest,IDNAInfo & info,UErrorCode & errorCode) const302 UTS46::process(const UnicodeString &src,
303                UBool isLabel, UBool toASCII,
304                UnicodeString &dest,
305                IDNAInfo &info, UErrorCode &errorCode) const {
306     // uts46Norm2.normalize() would do all of this error checking and setup,
307     // but with the ASCII fastpath we do not always call it, and do not
308     // call it first.
309     if(U_FAILURE(errorCode)) {
310         dest.setToBogus();
311         return dest;
312     }
313     const UChar *srcArray=src.getBuffer();
314     if(&dest==&src || srcArray==NULL) {
315         errorCode=U_ILLEGAL_ARGUMENT_ERROR;
316         dest.setToBogus();
317         return dest;
318     }
319     // Arguments are fine, reset output values.
320     dest.remove();
321     info.reset();
322     int32_t srcLength=src.length();
323     if(srcLength==0) {
324         info.errors|=UIDNA_ERROR_EMPTY_LABEL;
325         return dest;
326     }
327     UChar *destArray=dest.getBuffer(srcLength);
328     if(destArray==NULL) {
329         errorCode=U_MEMORY_ALLOCATION_ERROR;
330         return dest;
331     }
332     // ASCII fastpath
333     UBool disallowNonLDHDot=(options&UIDNA_USE_STD3_RULES)!=0;
334     int32_t labelStart=0;
335     int32_t i;
336     for(i=0;; ++i) {
337         if(i==srcLength) {
338             if(toASCII) {
339                 if((i-labelStart)>63) {
340                     info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
341                 }
342                 // There is a trailing dot if labelStart==i.
343                 if(!isLabel && i>=254 && (i>254 || labelStart<i)) {
344                     info.errors|=UIDNA_ERROR_DOMAIN_NAME_TOO_LONG;
345                 }
346             }
347             info.errors|=info.labelErrors;
348             dest.releaseBuffer(i);
349             return dest;
350         }
351         UChar c=srcArray[i];
352         if(c>0x7f) {
353             break;
354         }
355         int cData=asciiData[c];
356         if(cData>0) {
357             destArray[i]=c+0x20;  // Lowercase an uppercase ASCII letter.
358         } else if(cData<0 && disallowNonLDHDot) {
359             break;  // Replacing with U+FFFD can be complicated for toASCII.
360         } else {
361             destArray[i]=c;
362             if(c==0x2d) {  // hyphen
363                 if(i==(labelStart+3) && srcArray[i-1]==0x2d) {
364                     // "??--..." is Punycode or forbidden.
365                     ++i;  // '-' was copied to dest already
366                     break;
367                 }
368                 if(i==labelStart) {
369                     // label starts with "-"
370                     info.labelErrors|=UIDNA_ERROR_LEADING_HYPHEN;
371                 }
372                 if((i+1)==srcLength || srcArray[i+1]==0x2e) {
373                     // label ends with "-"
374                     info.labelErrors|=UIDNA_ERROR_TRAILING_HYPHEN;
375                 }
376             } else if(c==0x2e) {  // dot
377                 if(isLabel) {
378                     // Replacing with U+FFFD can be complicated for toASCII.
379                     ++i;  // '.' was copied to dest already
380                     break;
381                 }
382                 if(i==labelStart) {
383                     info.labelErrors|=UIDNA_ERROR_EMPTY_LABEL;
384                 }
385                 if(toASCII && (i-labelStart)>63) {
386                     info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
387                 }
388                 info.errors|=info.labelErrors;
389                 info.labelErrors=0;
390                 labelStart=i+1;
391             }
392         }
393     }
394     info.errors|=info.labelErrors;
395     dest.releaseBuffer(i);
396     processUnicode(src, labelStart, i, isLabel, toASCII, dest, info, errorCode);
397     if( info.isBiDi && U_SUCCESS(errorCode) && (info.errors&severeErrors)==0 &&
398         (!info.isOkBiDi || (labelStart>0 && !isASCIIOkBiDi(dest.getBuffer(), labelStart)))
399     ) {
400         info.errors|=UIDNA_ERROR_BIDI;
401     }
402     return dest;
403 }
404 
405 void
processUTF8(StringPiece src,UBool isLabel,UBool toASCII,ByteSink & dest,IDNAInfo & info,UErrorCode & errorCode) const406 UTS46::processUTF8(StringPiece src,
407                    UBool isLabel, UBool toASCII,
408                    ByteSink &dest,
409                    IDNAInfo &info, UErrorCode &errorCode) const {
410     if(U_FAILURE(errorCode)) {
411         return;
412     }
413     const char *srcArray=src.data();
414     int32_t srcLength=src.length();
415     if(srcArray==NULL && srcLength!=0) {
416         errorCode=U_ILLEGAL_ARGUMENT_ERROR;
417         return;
418     }
419     // Arguments are fine, reset output values.
420     info.reset();
421     if(srcLength==0) {
422         info.errors|=UIDNA_ERROR_EMPTY_LABEL;
423         dest.Flush();
424         return;
425     }
426     UnicodeString destString;
427     int32_t labelStart=0;
428     if(srcLength<=256) {  // length of stackArray[]
429         // ASCII fastpath
430         char stackArray[256];
431         int32_t destCapacity;
432         char *destArray=dest.GetAppendBuffer(srcLength, srcLength+20,
433                                              stackArray, UPRV_LENGTHOF(stackArray), &destCapacity);
434         UBool disallowNonLDHDot=(options&UIDNA_USE_STD3_RULES)!=0;
435         int32_t i;
436         for(i=0;; ++i) {
437             if(i==srcLength) {
438                 if(toASCII) {
439                     if((i-labelStart)>63) {
440                         info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
441                     }
442                     // There is a trailing dot if labelStart==i.
443                     if(!isLabel && i>=254 && (i>254 || labelStart<i)) {
444                         info.errors|=UIDNA_ERROR_DOMAIN_NAME_TOO_LONG;
445                     }
446                 }
447                 info.errors|=info.labelErrors;
448                 dest.Append(destArray, i);
449                 dest.Flush();
450                 return;
451             }
452             char c=srcArray[i];
453             if((int8_t)c<0) {  // (uint8_t)c>0x7f
454                 break;
455             }
456             int cData=asciiData[(int)c];  // Cast: gcc warns about indexing with a char.
457             if(cData>0) {
458                 destArray[i]=c+0x20;  // Lowercase an uppercase ASCII letter.
459             } else if(cData<0 && disallowNonLDHDot) {
460                 break;  // Replacing with U+FFFD can be complicated for toASCII.
461             } else {
462                 destArray[i]=c;
463                 if(c==0x2d) {  // hyphen
464                     if(i==(labelStart+3) && srcArray[i-1]==0x2d) {
465                         // "??--..." is Punycode or forbidden.
466                         break;
467                     }
468                     if(i==labelStart) {
469                         // label starts with "-"
470                         info.labelErrors|=UIDNA_ERROR_LEADING_HYPHEN;
471                     }
472                     if((i+1)==srcLength || srcArray[i+1]==0x2e) {
473                         // label ends with "-"
474                         info.labelErrors|=UIDNA_ERROR_TRAILING_HYPHEN;
475                     }
476                 } else if(c==0x2e) {  // dot
477                     if(isLabel) {
478                         break;  // Replacing with U+FFFD can be complicated for toASCII.
479                     }
480                     if(i==labelStart) {
481                         info.labelErrors|=UIDNA_ERROR_EMPTY_LABEL;
482                     }
483                     if(toASCII && (i-labelStart)>63) {
484                         info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
485                     }
486                     info.errors|=info.labelErrors;
487                     info.labelErrors=0;
488                     labelStart=i+1;
489                 }
490             }
491         }
492         info.errors|=info.labelErrors;
493         // Convert the processed ASCII prefix of the current label to UTF-16.
494         int32_t mappingStart=i-labelStart;
495         destString=UnicodeString::fromUTF8(StringPiece(destArray+labelStart, mappingStart));
496         // Output the previous ASCII labels and process the rest of src in UTF-16.
497         dest.Append(destArray, labelStart);
498         processUnicode(UnicodeString::fromUTF8(StringPiece(src, labelStart)), 0, mappingStart,
499                        isLabel, toASCII,
500                        destString, info, errorCode);
501     } else {
502         // src is too long for the ASCII fastpath implementation.
503         processUnicode(UnicodeString::fromUTF8(src), 0, 0,
504                        isLabel, toASCII,
505                        destString, info, errorCode);
506     }
507     destString.toUTF8(dest);  // calls dest.Flush()
508     if(toASCII && !isLabel) {
509         // length==labelStart==254 means that there is a trailing dot (ok) and
510         // destString is empty (do not index at 253-labelStart).
511         int32_t length=labelStart+destString.length();
512         if( length>=254 && isASCIIString(destString) &&
513             (length>254 ||
514              (labelStart<254 && destString[253-labelStart]!=0x2e))
515         ) {
516             info.errors|=UIDNA_ERROR_DOMAIN_NAME_TOO_LONG;
517         }
518     }
519     if( info.isBiDi && U_SUCCESS(errorCode) && (info.errors&severeErrors)==0 &&
520         (!info.isOkBiDi || (labelStart>0 && !isASCIIOkBiDi(srcArray, labelStart)))
521     ) {
522         info.errors|=UIDNA_ERROR_BIDI;
523     }
524 }
525 
526 UnicodeString &
processUnicode(const UnicodeString & src,int32_t labelStart,int32_t mappingStart,UBool isLabel,UBool toASCII,UnicodeString & dest,IDNAInfo & info,UErrorCode & errorCode) const527 UTS46::processUnicode(const UnicodeString &src,
528                       int32_t labelStart, int32_t mappingStart,
529                       UBool isLabel, UBool toASCII,
530                       UnicodeString &dest,
531                       IDNAInfo &info, UErrorCode &errorCode) const {
532     if(mappingStart==0) {
533         uts46Norm2.normalize(src, dest, errorCode);
534     } else {
535         uts46Norm2.normalizeSecondAndAppend(dest, src.tempSubString(mappingStart), errorCode);
536     }
537     if(U_FAILURE(errorCode)) {
538         return dest;
539     }
540     UBool doMapDevChars=
541         toASCII ? (options&UIDNA_NONTRANSITIONAL_TO_ASCII)==0 :
542                   (options&UIDNA_NONTRANSITIONAL_TO_UNICODE)==0;
543     const UChar *destArray=dest.getBuffer();
544     int32_t destLength=dest.length();
545     int32_t labelLimit=labelStart;
546     while(labelLimit<destLength) {
547         UChar c=destArray[labelLimit];
548         if(c==0x2e && !isLabel) {
549             int32_t labelLength=labelLimit-labelStart;
550             int32_t newLength=processLabel(dest, labelStart, labelLength,
551                                             toASCII, info, errorCode);
552             info.errors|=info.labelErrors;
553             info.labelErrors=0;
554             if(U_FAILURE(errorCode)) {
555                 return dest;
556             }
557             destArray=dest.getBuffer();
558             destLength+=newLength-labelLength;
559             labelLimit=labelStart+=newLength+1;
560             continue;
561         } else if(c<0xdf) {
562             // pass
563         } else if(c<=0x200d && (c==0xdf || c==0x3c2 || c>=0x200c)) {
564             info.isTransDiff=TRUE;
565             if(doMapDevChars) {
566                 destLength=mapDevChars(dest, labelStart, labelLimit, errorCode);
567                 if(U_FAILURE(errorCode)) {
568                     return dest;
569                 }
570                 destArray=dest.getBuffer();
571                 // All deviation characters have been mapped, no need to check for them again.
572                 doMapDevChars=FALSE;
573                 // Do not increment labelLimit in case c was removed.
574                 continue;
575             }
576         } else if(U16_IS_SURROGATE(c)) {
577             if(U16_IS_SURROGATE_LEAD(c) ?
578                     (labelLimit+1)==destLength || !U16_IS_TRAIL(destArray[labelLimit+1]) :
579                     labelLimit==labelStart || !U16_IS_LEAD(destArray[labelLimit-1])) {
580                 // Map an unpaired surrogate to U+FFFD before normalization so that when
581                 // that removes characters we do not turn two unpaired ones into a pair.
582                 info.labelErrors|=UIDNA_ERROR_DISALLOWED;
583                 dest.setCharAt(labelLimit, 0xfffd);
584                 destArray=dest.getBuffer();
585             }
586         }
587         ++labelLimit;
588     }
589     // Permit an empty label at the end (0<labelStart==labelLimit==destLength is ok)
590     // but not an empty label elsewhere nor a completely empty domain name.
591     // processLabel() sets UIDNA_ERROR_EMPTY_LABEL when labelLength==0.
592     if(0==labelStart || labelStart<labelLimit) {
593         processLabel(dest, labelStart, labelLimit-labelStart,
594                       toASCII, info, errorCode);
595         info.errors|=info.labelErrors;
596     }
597     return dest;
598 }
599 
600 int32_t
mapDevChars(UnicodeString & dest,int32_t labelStart,int32_t mappingStart,UErrorCode & errorCode) const601 UTS46::mapDevChars(UnicodeString &dest, int32_t labelStart, int32_t mappingStart,
602                    UErrorCode &errorCode) const {
603     if(U_FAILURE(errorCode)) {
604         return 0;
605     }
606     int32_t length=dest.length();
607     UChar *s=dest.getBuffer(dest[mappingStart]==0xdf ? length+1 : length);
608     if(s==NULL) {
609         errorCode=U_MEMORY_ALLOCATION_ERROR;
610         return length;
611     }
612     int32_t capacity=dest.getCapacity();
613     UBool didMapDevChars=FALSE;
614     int32_t readIndex=mappingStart, writeIndex=mappingStart;
615     do {
616         UChar c=s[readIndex++];
617         switch(c) {
618         case 0xdf:
619             // Map sharp s to ss.
620             didMapDevChars=TRUE;
621             s[writeIndex++]=0x73;  // Replace sharp s with first s.
622             // Insert second s and account for possible buffer reallocation.
623             if(writeIndex==readIndex) {
624                 if(length==capacity) {
625                     dest.releaseBuffer(length);
626                     s=dest.getBuffer(length+1);
627                     if(s==NULL) {
628                         errorCode=U_MEMORY_ALLOCATION_ERROR;
629                         return length;
630                     }
631                     capacity=dest.getCapacity();
632                 }
633                 u_memmove(s+writeIndex+1, s+writeIndex, length-writeIndex);
634                 ++readIndex;
635             }
636             s[writeIndex++]=0x73;
637             ++length;
638             break;
639         case 0x3c2:  // Map final sigma to nonfinal sigma.
640             didMapDevChars=TRUE;
641             s[writeIndex++]=0x3c3;
642             break;
643         case 0x200c:  // Ignore/remove ZWNJ.
644         case 0x200d:  // Ignore/remove ZWJ.
645             didMapDevChars=TRUE;
646             --length;
647             break;
648         default:
649             // Only really necessary if writeIndex was different from readIndex.
650             s[writeIndex++]=c;
651             break;
652         }
653     } while(writeIndex<length);
654     dest.releaseBuffer(length);
655     if(didMapDevChars) {
656         // Mapping deviation characters might have resulted in an un-NFC string.
657         // We could use either the NFC or the UTS #46 normalizer.
658         // By using the UTS #46 normalizer again, we avoid having to load a second .nrm data file.
659         UnicodeString normalized;
660         uts46Norm2.normalize(dest.tempSubString(labelStart), normalized, errorCode);
661         if(U_SUCCESS(errorCode)) {
662             dest.replace(labelStart, 0x7fffffff, normalized);
663             if(dest.isBogus()) {
664                 errorCode=U_MEMORY_ALLOCATION_ERROR;
665             }
666             return dest.length();
667         }
668     }
669     return length;
670 }
671 
672 // Some non-ASCII characters are equivalent to sequences with
673 // non-LDH ASCII characters. To find them:
674 // grep disallowed_STD3_valid IdnaMappingTable.txt (or uts46.txt)
675 static inline UBool
isNonASCIIDisallowedSTD3Valid(UChar32 c)676 isNonASCIIDisallowedSTD3Valid(UChar32 c) {
677     return c==0x2260 || c==0x226E || c==0x226F;
678 }
679 
680 // Replace the label in dest with the label string, if the label was modified.
681 // If &label==&dest then the label was modified in-place and labelLength
682 // is the new label length, different from label.length().
683 // If &label!=&dest then labelLength==label.length().
684 // Returns labelLength (= the new label length).
685 static int32_t
replaceLabel(UnicodeString & dest,int32_t destLabelStart,int32_t destLabelLength,const UnicodeString & label,int32_t labelLength,UErrorCode & errorCode)686 replaceLabel(UnicodeString &dest, int32_t destLabelStart, int32_t destLabelLength,
687              const UnicodeString &label, int32_t labelLength, UErrorCode &errorCode) {
688     if(U_FAILURE(errorCode)) {
689         return 0;
690     }
691     if(&label!=&dest) {
692         dest.replace(destLabelStart, destLabelLength, label);
693         if(dest.isBogus()) {
694             errorCode=U_MEMORY_ALLOCATION_ERROR;
695             return 0;
696         }
697     }
698     return labelLength;
699 }
700 
701 int32_t
processLabel(UnicodeString & dest,int32_t labelStart,int32_t labelLength,UBool toASCII,IDNAInfo & info,UErrorCode & errorCode) const702 UTS46::processLabel(UnicodeString &dest,
703                     int32_t labelStart, int32_t labelLength,
704                     UBool toASCII,
705                     IDNAInfo &info, UErrorCode &errorCode) const {
706     if(U_FAILURE(errorCode)) {
707         return 0;
708     }
709     UnicodeString fromPunycode;
710     UnicodeString *labelString;
711     const UChar *label=dest.getBuffer()+labelStart;
712     int32_t destLabelStart=labelStart;
713     int32_t destLabelLength=labelLength;
714     UBool wasPunycode;
715     if(labelLength>=4 && label[0]==0x78 && label[1]==0x6e && label[2]==0x2d && label[3]==0x2d) {
716         // Label starts with "xn--", try to un-Punycode it.
717         // In IDNA2008, labels like "xn--" (decodes to an empty string) and
718         // "xn--ASCII-" (decodes to just "ASCII") fail the round-trip validation from
719         // comparing the ToUnicode input with the back-to-ToASCII output.
720         // They are alternate encodings of the respective ASCII labels.
721         // Ignore "xn---" here: It will fail Punycode.decode() which logically comes before
722         // the round-trip verification.
723         if(labelLength==4 || (labelLength>5 && label[labelLength-1]==u'-')) {
724             info.labelErrors|=UIDNA_ERROR_INVALID_ACE_LABEL;
725             return markBadACELabel(dest, labelStart, labelLength, toASCII, info, errorCode);
726         }
727         wasPunycode=TRUE;
728         UChar *unicodeBuffer=fromPunycode.getBuffer(-1);  // capacity==-1: most labels should fit
729         if(unicodeBuffer==NULL) {
730             // Should never occur if we used capacity==-1 which uses the internal buffer.
731             errorCode=U_MEMORY_ALLOCATION_ERROR;
732             return labelLength;
733         }
734         UErrorCode punycodeErrorCode=U_ZERO_ERROR;
735         int32_t unicodeLength=u_strFromPunycode(label+4, labelLength-4,
736                                                 unicodeBuffer, fromPunycode.getCapacity(),
737                                                 NULL, &punycodeErrorCode);
738         if(punycodeErrorCode==U_BUFFER_OVERFLOW_ERROR) {
739             fromPunycode.releaseBuffer(0);
740             unicodeBuffer=fromPunycode.getBuffer(unicodeLength);
741             if(unicodeBuffer==NULL) {
742                 errorCode=U_MEMORY_ALLOCATION_ERROR;
743                 return labelLength;
744             }
745             punycodeErrorCode=U_ZERO_ERROR;
746             unicodeLength=u_strFromPunycode(label+4, labelLength-4,
747                                             unicodeBuffer, fromPunycode.getCapacity(),
748                                             NULL, &punycodeErrorCode);
749         }
750         fromPunycode.releaseBuffer(unicodeLength);
751         if(U_FAILURE(punycodeErrorCode)) {
752             info.labelErrors|=UIDNA_ERROR_PUNYCODE;
753             return markBadACELabel(dest, labelStart, labelLength, toASCII, info, errorCode);
754         }
755         // Check for NFC, and for characters that are not
756         // valid or deviation characters according to the normalizer.
757         // If there is something wrong, then the string will change.
758         // Note that the normalizer passes through non-LDH ASCII and deviation characters.
759         // Deviation characters are ok in Punycode even in transitional processing.
760         // In the code further below, if we find non-LDH ASCII and we have UIDNA_USE_STD3_RULES
761         // then we will set UIDNA_ERROR_INVALID_ACE_LABEL there too.
762         UBool isValid=uts46Norm2.isNormalized(fromPunycode, errorCode);
763         if(U_FAILURE(errorCode)) {
764             return labelLength;
765         }
766         if(!isValid) {
767             info.labelErrors|=UIDNA_ERROR_INVALID_ACE_LABEL;
768             return markBadACELabel(dest, labelStart, labelLength, toASCII, info, errorCode);
769         }
770         labelString=&fromPunycode;
771         label=fromPunycode.getBuffer();
772         labelStart=0;
773         labelLength=fromPunycode.length();
774     } else {
775         wasPunycode=FALSE;
776         labelString=&dest;
777     }
778     // Validity check
779     if(labelLength==0) {
780         info.labelErrors|=UIDNA_ERROR_EMPTY_LABEL;
781         return replaceLabel(dest, destLabelStart, destLabelLength,
782                             *labelString, labelLength, errorCode);
783     }
784     // labelLength>0
785     if(labelLength>=4 && label[2]==0x2d && label[3]==0x2d) {
786         // label starts with "??--"
787         info.labelErrors|=UIDNA_ERROR_HYPHEN_3_4;
788     }
789     if(label[0]==0x2d) {
790         // label starts with "-"
791         info.labelErrors|=UIDNA_ERROR_LEADING_HYPHEN;
792     }
793     if(label[labelLength-1]==0x2d) {
794         // label ends with "-"
795         info.labelErrors|=UIDNA_ERROR_TRAILING_HYPHEN;
796     }
797     // If the label was not a Punycode label, then it was the result of
798     // mapping, normalization and label segmentation.
799     // If the label was in Punycode, then we mapped it again above
800     // and checked its validity.
801     // Now we handle the STD3 restriction to LDH characters (if set)
802     // and we look for U+FFFD which indicates disallowed characters
803     // in a non-Punycode label or U+FFFD itself in a Punycode label.
804     // We also check for dots which can come from the input to a single-label function.
805     // Ok to cast away const because we own the UnicodeString.
806     UChar *s=(UChar *)label;
807     const UChar *limit=label+labelLength;
808     UChar oredChars=0;
809     // If we enforce STD3 rules, then ASCII characters other than LDH and dot are disallowed.
810     UBool disallowNonLDHDot=(options&UIDNA_USE_STD3_RULES)!=0;
811     do {
812         UChar c=*s;
813         if(c<=0x7f) {
814             if(c==0x2e) {
815                 info.labelErrors|=UIDNA_ERROR_LABEL_HAS_DOT;
816                 *s=0xfffd;
817             } else if(disallowNonLDHDot && asciiData[c]<0) {
818                 info.labelErrors|=UIDNA_ERROR_DISALLOWED;
819                 *s=0xfffd;
820             }
821         } else {
822             oredChars|=c;
823             if(disallowNonLDHDot && isNonASCIIDisallowedSTD3Valid(c)) {
824                 info.labelErrors|=UIDNA_ERROR_DISALLOWED;
825                 *s=0xfffd;
826             } else if(c==0xfffd) {
827                 info.labelErrors|=UIDNA_ERROR_DISALLOWED;
828             }
829         }
830         ++s;
831     } while(s<limit);
832     // Check for a leading combining mark after other validity checks
833     // so that we don't report UIDNA_ERROR_DISALLOWED for the U+FFFD from here.
834     UChar32 c;
835     int32_t cpLength=0;
836     // "Unsafe" is ok because unpaired surrogates were mapped to U+FFFD.
837     U16_NEXT_UNSAFE(label, cpLength, c);
838     if((U_GET_GC_MASK(c)&U_GC_M_MASK)!=0) {
839         info.labelErrors|=UIDNA_ERROR_LEADING_COMBINING_MARK;
840         labelString->replace(labelStart, cpLength, (UChar)0xfffd);
841         label=labelString->getBuffer()+labelStart;
842         labelLength+=1-cpLength;
843         if(labelString==&dest) {
844             destLabelLength=labelLength;
845         }
846     }
847     if((info.labelErrors&severeErrors)==0) {
848         // Do contextual checks only if we do not have U+FFFD from a severe error
849         // because U+FFFD can make these checks fail.
850         if((options&UIDNA_CHECK_BIDI)!=0 && (!info.isBiDi || info.isOkBiDi)) {
851             checkLabelBiDi(label, labelLength, info);
852         }
853         if( (options&UIDNA_CHECK_CONTEXTJ)!=0 && (oredChars&0x200c)==0x200c &&
854             !isLabelOkContextJ(label, labelLength)
855         ) {
856             info.labelErrors|=UIDNA_ERROR_CONTEXTJ;
857         }
858         if((options&UIDNA_CHECK_CONTEXTO)!=0 && oredChars>=0xb7) {
859             checkLabelContextO(label, labelLength, info);
860         }
861         if(toASCII) {
862             if(wasPunycode) {
863                 // Leave a Punycode label unchanged if it has no severe errors.
864                 if(destLabelLength>63) {
865                     info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
866                 }
867                 return destLabelLength;
868             } else if(oredChars>=0x80) {
869                 // Contains non-ASCII characters.
870                 UnicodeString punycode;
871                 UChar *buffer=punycode.getBuffer(63);  // 63==maximum DNS label length
872                 if(buffer==NULL) {
873                     errorCode=U_MEMORY_ALLOCATION_ERROR;
874                     return destLabelLength;
875                 }
876                 buffer[0]=0x78;  // Write "xn--".
877                 buffer[1]=0x6e;
878                 buffer[2]=0x2d;
879                 buffer[3]=0x2d;
880                 int32_t punycodeLength=u_strToPunycode(label, labelLength,
881                                                       buffer+4, punycode.getCapacity()-4,
882                                                       NULL, &errorCode);
883                 if(errorCode==U_BUFFER_OVERFLOW_ERROR) {
884                     errorCode=U_ZERO_ERROR;
885                     punycode.releaseBuffer(4);
886                     buffer=punycode.getBuffer(4+punycodeLength);
887                     if(buffer==NULL) {
888                         errorCode=U_MEMORY_ALLOCATION_ERROR;
889                         return destLabelLength;
890                     }
891                     punycodeLength=u_strToPunycode(label, labelLength,
892                                                   buffer+4, punycode.getCapacity()-4,
893                                                   NULL, &errorCode);
894                 }
895                 punycodeLength+=4;
896                 punycode.releaseBuffer(punycodeLength);
897                 if(U_FAILURE(errorCode)) {
898                     return destLabelLength;
899                 }
900                 if(punycodeLength>63) {
901                     info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
902                 }
903                 return replaceLabel(dest, destLabelStart, destLabelLength,
904                                     punycode, punycodeLength, errorCode);
905             } else {
906                 // all-ASCII label
907                 if(labelLength>63) {
908                     info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
909                 }
910             }
911         }
912     } else {
913         // If a Punycode label has severe errors,
914         // then leave it but make sure it does not look valid.
915         if(wasPunycode) {
916             info.labelErrors|=UIDNA_ERROR_INVALID_ACE_LABEL;
917             return markBadACELabel(dest, destLabelStart, destLabelLength, toASCII, info, errorCode);
918         }
919     }
920     return replaceLabel(dest, destLabelStart, destLabelLength,
921                         *labelString, labelLength, errorCode);
922 }
923 
924 // Make sure an ACE label does not look valid.
925 // Append U+FFFD if the label has only LDH characters.
926 // If UIDNA_USE_STD3_RULES, also replace disallowed ASCII characters with U+FFFD.
927 int32_t
markBadACELabel(UnicodeString & dest,int32_t labelStart,int32_t labelLength,UBool toASCII,IDNAInfo & info,UErrorCode & errorCode) const928 UTS46::markBadACELabel(UnicodeString &dest,
929                        int32_t labelStart, int32_t labelLength,
930                        UBool toASCII, IDNAInfo &info, UErrorCode &errorCode) const {
931     if(U_FAILURE(errorCode)) {
932         return 0;
933     }
934     UBool disallowNonLDHDot=(options&UIDNA_USE_STD3_RULES)!=0;
935     UBool isASCII=TRUE;
936     UBool onlyLDH=TRUE;
937     const UChar *label=dest.getBuffer()+labelStart;
938     const UChar *limit=label+labelLength;
939     // Start after the initial "xn--".
940     // Ok to cast away const because we own the UnicodeString.
941     for(UChar *s=const_cast<UChar *>(label+4); s<limit; ++s) {
942         UChar c=*s;
943         if(c<=0x7f) {
944             if(c==0x2e) {
945                 info.labelErrors|=UIDNA_ERROR_LABEL_HAS_DOT;
946                 *s=0xfffd;
947                 isASCII=onlyLDH=FALSE;
948             } else if(asciiData[c]<0) {
949                 onlyLDH=FALSE;
950                 if(disallowNonLDHDot) {
951                     *s=0xfffd;
952                     isASCII=FALSE;
953                 }
954             }
955         } else {
956             isASCII=onlyLDH=FALSE;
957         }
958     }
959     if(onlyLDH) {
960         dest.insert(labelStart+labelLength, (UChar)0xfffd);
961         if(dest.isBogus()) {
962             errorCode=U_MEMORY_ALLOCATION_ERROR;
963             return 0;
964         }
965         ++labelLength;
966     } else {
967         if(toASCII && isASCII && labelLength>63) {
968             info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
969         }
970     }
971     return labelLength;
972 }
973 
974 const uint32_t L_MASK=U_MASK(U_LEFT_TO_RIGHT);
975 const uint32_t R_AL_MASK=U_MASK(U_RIGHT_TO_LEFT)|U_MASK(U_RIGHT_TO_LEFT_ARABIC);
976 const uint32_t L_R_AL_MASK=L_MASK|R_AL_MASK;
977 
978 const uint32_t R_AL_AN_MASK=R_AL_MASK|U_MASK(U_ARABIC_NUMBER);
979 
980 const uint32_t EN_AN_MASK=U_MASK(U_EUROPEAN_NUMBER)|U_MASK(U_ARABIC_NUMBER);
981 const uint32_t R_AL_EN_AN_MASK=R_AL_MASK|EN_AN_MASK;
982 const uint32_t L_EN_MASK=L_MASK|U_MASK(U_EUROPEAN_NUMBER);
983 
984 const uint32_t ES_CS_ET_ON_BN_NSM_MASK=
985     U_MASK(U_EUROPEAN_NUMBER_SEPARATOR)|
986     U_MASK(U_COMMON_NUMBER_SEPARATOR)|
987     U_MASK(U_EUROPEAN_NUMBER_TERMINATOR)|
988     U_MASK(U_OTHER_NEUTRAL)|
989     U_MASK(U_BOUNDARY_NEUTRAL)|
990     U_MASK(U_DIR_NON_SPACING_MARK);
991 const uint32_t L_EN_ES_CS_ET_ON_BN_NSM_MASK=L_EN_MASK|ES_CS_ET_ON_BN_NSM_MASK;
992 const uint32_t R_AL_AN_EN_ES_CS_ET_ON_BN_NSM_MASK=R_AL_MASK|EN_AN_MASK|ES_CS_ET_ON_BN_NSM_MASK;
993 
994 // We scan the whole label and check both for whether it contains RTL characters
995 // and whether it passes the BiDi Rule.
996 // In a BiDi domain name, all labels must pass the BiDi Rule, but we might find
997 // that a domain name is a BiDi domain name (has an RTL label) only after
998 // processing several earlier labels.
999 void
checkLabelBiDi(const UChar * label,int32_t labelLength,IDNAInfo & info) const1000 UTS46::checkLabelBiDi(const UChar *label, int32_t labelLength, IDNAInfo &info) const {
1001     // IDNA2008 BiDi rule
1002     // Get the directionality of the first character.
1003     UChar32 c;
1004     int32_t i=0;
1005     U16_NEXT_UNSAFE(label, i, c);
1006     uint32_t firstMask=U_MASK(u_charDirection(c));
1007     // 1. The first character must be a character with BIDI property L, R
1008     // or AL.  If it has the R or AL property, it is an RTL label; if it
1009     // has the L property, it is an LTR label.
1010     if((firstMask&~L_R_AL_MASK)!=0) {
1011         info.isOkBiDi=FALSE;
1012     }
1013     // Get the directionality of the last non-NSM character.
1014     uint32_t lastMask;
1015     for(;;) {
1016         if(i>=labelLength) {
1017             lastMask=firstMask;
1018             break;
1019         }
1020         U16_PREV_UNSAFE(label, labelLength, c);
1021         UCharDirection dir=u_charDirection(c);
1022         if(dir!=U_DIR_NON_SPACING_MARK) {
1023             lastMask=U_MASK(dir);
1024             break;
1025         }
1026     }
1027     // 3. In an RTL label, the end of the label must be a character with
1028     // BIDI property R, AL, EN or AN, followed by zero or more
1029     // characters with BIDI property NSM.
1030     // 6. In an LTR label, the end of the label must be a character with
1031     // BIDI property L or EN, followed by zero or more characters with
1032     // BIDI property NSM.
1033     if( (firstMask&L_MASK)!=0 ?
1034             (lastMask&~L_EN_MASK)!=0 :
1035             (lastMask&~R_AL_EN_AN_MASK)!=0
1036     ) {
1037         info.isOkBiDi=FALSE;
1038     }
1039     // Add the directionalities of the intervening characters.
1040     uint32_t mask=firstMask|lastMask;
1041     while(i<labelLength) {
1042         U16_NEXT_UNSAFE(label, i, c);
1043         mask|=U_MASK(u_charDirection(c));
1044     }
1045     if(firstMask&L_MASK) {
1046         // 5. In an LTR label, only characters with the BIDI properties L, EN,
1047         // ES, CS, ET, ON, BN and NSM are allowed.
1048         if((mask&~L_EN_ES_CS_ET_ON_BN_NSM_MASK)!=0) {
1049             info.isOkBiDi=FALSE;
1050         }
1051     } else {
1052         // 2. In an RTL label, only characters with the BIDI properties R, AL,
1053         // AN, EN, ES, CS, ET, ON, BN and NSM are allowed.
1054         if((mask&~R_AL_AN_EN_ES_CS_ET_ON_BN_NSM_MASK)!=0) {
1055             info.isOkBiDi=FALSE;
1056         }
1057         // 4. In an RTL label, if an EN is present, no AN may be present, and
1058         // vice versa.
1059         if((mask&EN_AN_MASK)==EN_AN_MASK) {
1060             info.isOkBiDi=FALSE;
1061         }
1062     }
1063     // An RTL label is a label that contains at least one character of type
1064     // R, AL or AN. [...]
1065     // A "BIDI domain name" is a domain name that contains at least one RTL
1066     // label. [...]
1067     // The following rule, consisting of six conditions, applies to labels
1068     // in BIDI domain names.
1069     if((mask&R_AL_AN_MASK)!=0) {
1070         info.isBiDi=TRUE;
1071     }
1072 }
1073 
1074 // Special code for the ASCII prefix of a BiDi domain name.
1075 // The ASCII prefix is all-LTR.
1076 
1077 // IDNA2008 BiDi rule, parts relevant to ASCII labels:
1078 // 1. The first character must be a character with BIDI property L [...]
1079 // 5. In an LTR label, only characters with the BIDI properties L, EN,
1080 // ES, CS, ET, ON, BN and NSM are allowed.
1081 // 6. In an LTR label, the end of the label must be a character with
1082 // BIDI property L or EN [...]
1083 
1084 // UTF-16 version, called for mapped ASCII prefix.
1085 // Cannot contain uppercase A-Z.
1086 // s[length-1] must be the trailing dot.
1087 static UBool
isASCIIOkBiDi(const UChar * s,int32_t length)1088 isASCIIOkBiDi(const UChar *s, int32_t length) {
1089     int32_t labelStart=0;
1090     for(int32_t i=0; i<length; ++i) {
1091         UChar c=s[i];
1092         if(c==0x2e) {  // dot
1093             if(i>labelStart) {
1094                 c=s[i-1];
1095                 if(!(0x61<=c && c<=0x7a) && !(0x30<=c && c<=0x39)) {
1096                     // Last character in the label is not an L or EN.
1097                     return FALSE;
1098                 }
1099             }
1100             labelStart=i+1;
1101         } else if(i==labelStart) {
1102             if(!(0x61<=c && c<=0x7a)) {
1103                 // First character in the label is not an L.
1104                 return FALSE;
1105             }
1106         } else {
1107             if(c<=0x20 && (c>=0x1c || (9<=c && c<=0xd))) {
1108                 // Intermediate character in the label is a B, S or WS.
1109                 return FALSE;
1110             }
1111         }
1112     }
1113     return TRUE;
1114 }
1115 
1116 // UTF-8 version, called for source ASCII prefix.
1117 // Can contain uppercase A-Z.
1118 // s[length-1] must be the trailing dot.
1119 static UBool
isASCIIOkBiDi(const char * s,int32_t length)1120 isASCIIOkBiDi(const char *s, int32_t length) {
1121     int32_t labelStart=0;
1122     for(int32_t i=0; i<length; ++i) {
1123         char c=s[i];
1124         if(c==0x2e) {  // dot
1125             if(i>labelStart) {
1126                 c=s[i-1];
1127                 if(!(0x61<=c && c<=0x7a) && !(0x41<=c && c<=0x5a) && !(0x30<=c && c<=0x39)) {
1128                     // Last character in the label is not an L or EN.
1129                     return FALSE;
1130                 }
1131             }
1132             labelStart=i+1;
1133         } else if(i==labelStart) {
1134             if(!(0x61<=c && c<=0x7a) && !(0x41<=c && c<=0x5a)) {
1135                 // First character in the label is not an L.
1136                 return FALSE;
1137             }
1138         } else {
1139             if(c<=0x20 && (c>=0x1c || (9<=c && c<=0xd))) {
1140                 // Intermediate character in the label is a B, S or WS.
1141                 return FALSE;
1142             }
1143         }
1144     }
1145     return TRUE;
1146 }
1147 
1148 UBool
isLabelOkContextJ(const UChar * label,int32_t labelLength) const1149 UTS46::isLabelOkContextJ(const UChar *label, int32_t labelLength) const {
1150     // [IDNA2008-Tables]
1151     // 200C..200D  ; CONTEXTJ    # ZERO WIDTH NON-JOINER..ZERO WIDTH JOINER
1152     for(int32_t i=0; i<labelLength; ++i) {
1153         if(label[i]==0x200c) {
1154             // Appendix A.1. ZERO WIDTH NON-JOINER
1155             // Rule Set:
1156             //  False;
1157             //  If Canonical_Combining_Class(Before(cp)) .eq.  Virama Then True;
1158             //  If RegExpMatch((Joining_Type:{L,D})(Joining_Type:T)*\u200C
1159             //     (Joining_Type:T)*(Joining_Type:{R,D})) Then True;
1160             if(i==0) {
1161                 return FALSE;
1162             }
1163             UChar32 c;
1164             int32_t j=i;
1165             U16_PREV_UNSAFE(label, j, c);
1166             if(uts46Norm2.getCombiningClass(c)==9) {
1167                 continue;
1168             }
1169             // check precontext (Joining_Type:{L,D})(Joining_Type:T)*
1170             for(;;) {
1171                 UJoiningType type=ubidi_getJoiningType(c);
1172                 if(type==U_JT_TRANSPARENT) {
1173                     if(j==0) {
1174                         return FALSE;
1175                     }
1176                     U16_PREV_UNSAFE(label, j, c);
1177                 } else if(type==U_JT_LEFT_JOINING || type==U_JT_DUAL_JOINING) {
1178                     break;  // precontext fulfilled
1179                 } else {
1180                     return FALSE;
1181                 }
1182             }
1183             // check postcontext (Joining_Type:T)*(Joining_Type:{R,D})
1184             for(j=i+1;;) {
1185                 if(j==labelLength) {
1186                     return FALSE;
1187                 }
1188                 U16_NEXT_UNSAFE(label, j, c);
1189                 UJoiningType type=ubidi_getJoiningType(c);
1190                 if(type==U_JT_TRANSPARENT) {
1191                     // just skip this character
1192                 } else if(type==U_JT_RIGHT_JOINING || type==U_JT_DUAL_JOINING) {
1193                     break;  // postcontext fulfilled
1194                 } else {
1195                     return FALSE;
1196                 }
1197             }
1198         } else if(label[i]==0x200d) {
1199             // Appendix A.2. ZERO WIDTH JOINER (U+200D)
1200             // Rule Set:
1201             //  False;
1202             //  If Canonical_Combining_Class(Before(cp)) .eq.  Virama Then True;
1203             if(i==0) {
1204                 return FALSE;
1205             }
1206             UChar32 c;
1207             int32_t j=i;
1208             U16_PREV_UNSAFE(label, j, c);
1209             if(uts46Norm2.getCombiningClass(c)!=9) {
1210                 return FALSE;
1211             }
1212         }
1213     }
1214     return TRUE;
1215 }
1216 
1217 void
checkLabelContextO(const UChar * label,int32_t labelLength,IDNAInfo & info) const1218 UTS46::checkLabelContextO(const UChar *label, int32_t labelLength, IDNAInfo &info) const {
1219     int32_t labelEnd=labelLength-1;  // inclusive
1220     int32_t arabicDigits=0;  // -1 for 066x, +1 for 06Fx
1221     for(int32_t i=0; i<=labelEnd; ++i) {
1222         UChar32 c=label[i];
1223         if(c<0xb7) {
1224             // ASCII fastpath
1225         } else if(c<=0x6f9) {
1226             if(c==0xb7) {
1227                 // Appendix A.3. MIDDLE DOT (U+00B7)
1228                 // Rule Set:
1229                 //  False;
1230                 //  If Before(cp) .eq.  U+006C And
1231                 //     After(cp) .eq.  U+006C Then True;
1232                 if(!(0<i && label[i-1]==0x6c &&
1233                      i<labelEnd && label[i+1]==0x6c)) {
1234                     info.labelErrors|=UIDNA_ERROR_CONTEXTO_PUNCTUATION;
1235                 }
1236             } else if(c==0x375) {
1237                 // Appendix A.4. GREEK LOWER NUMERAL SIGN (KERAIA) (U+0375)
1238                 // Rule Set:
1239                 //  False;
1240                 //  If Script(After(cp)) .eq.  Greek Then True;
1241                 UScriptCode script=USCRIPT_INVALID_CODE;
1242                 if(i<labelEnd) {
1243                     UErrorCode errorCode=U_ZERO_ERROR;
1244                     int32_t j=i+1;
1245                     U16_NEXT(label, j, labelLength, c);
1246                     script=uscript_getScript(c, &errorCode);
1247                 }
1248                 if(script!=USCRIPT_GREEK) {
1249                     info.labelErrors|=UIDNA_ERROR_CONTEXTO_PUNCTUATION;
1250                 }
1251             } else if(c==0x5f3 || c==0x5f4) {
1252                 // Appendix A.5. HEBREW PUNCTUATION GERESH (U+05F3)
1253                 // Rule Set:
1254                 //  False;
1255                 //  If Script(Before(cp)) .eq.  Hebrew Then True;
1256                 //
1257                 // Appendix A.6. HEBREW PUNCTUATION GERSHAYIM (U+05F4)
1258                 // Rule Set:
1259                 //  False;
1260                 //  If Script(Before(cp)) .eq.  Hebrew Then True;
1261                 UScriptCode script=USCRIPT_INVALID_CODE;
1262                 if(0<i) {
1263                     UErrorCode errorCode=U_ZERO_ERROR;
1264                     int32_t j=i;
1265                     U16_PREV(label, 0, j, c);
1266                     script=uscript_getScript(c, &errorCode);
1267                 }
1268                 if(script!=USCRIPT_HEBREW) {
1269                     info.labelErrors|=UIDNA_ERROR_CONTEXTO_PUNCTUATION;
1270                 }
1271             } else if(0x660<=c /* && c<=0x6f9 */) {
1272                 // Appendix A.8. ARABIC-INDIC DIGITS (0660..0669)
1273                 // Rule Set:
1274                 //  True;
1275                 //  For All Characters:
1276                 //    If cp .in. 06F0..06F9 Then False;
1277                 //  End For;
1278                 //
1279                 // Appendix A.9. EXTENDED ARABIC-INDIC DIGITS (06F0..06F9)
1280                 // Rule Set:
1281                 //  True;
1282                 //  For All Characters:
1283                 //    If cp .in. 0660..0669 Then False;
1284                 //  End For;
1285                 if(c<=0x669) {
1286                     if(arabicDigits>0) {
1287                         info.labelErrors|=UIDNA_ERROR_CONTEXTO_DIGITS;
1288                     }
1289                     arabicDigits=-1;
1290                 } else if(0x6f0<=c) {
1291                     if(arabicDigits<0) {
1292                         info.labelErrors|=UIDNA_ERROR_CONTEXTO_DIGITS;
1293                     }
1294                     arabicDigits=1;
1295                 }
1296             }
1297         } else if(c==0x30fb) {
1298             // Appendix A.7. KATAKANA MIDDLE DOT (U+30FB)
1299             // Rule Set:
1300             //  False;
1301             //  For All Characters:
1302             //    If Script(cp) .in. {Hiragana, Katakana, Han} Then True;
1303             //  End For;
1304             UErrorCode errorCode=U_ZERO_ERROR;
1305             for(int j=0;;) {
1306                 if(j>labelEnd) {
1307                     info.labelErrors|=UIDNA_ERROR_CONTEXTO_PUNCTUATION;
1308                     break;
1309                 }
1310                 U16_NEXT(label, j, labelLength, c);
1311                 UScriptCode script=uscript_getScript(c, &errorCode);
1312                 if(script==USCRIPT_HIRAGANA || script==USCRIPT_KATAKANA || script==USCRIPT_HAN) {
1313                     break;
1314                 }
1315             }
1316         }
1317     }
1318 }
1319 
1320 U_NAMESPACE_END
1321 
1322 // C API ------------------------------------------------------------------- ***
1323 
1324 U_NAMESPACE_USE
1325 
1326 U_CAPI UIDNA * U_EXPORT2
uidna_openUTS46(uint32_t options,UErrorCode * pErrorCode)1327 uidna_openUTS46(uint32_t options, UErrorCode *pErrorCode) {
1328     return reinterpret_cast<UIDNA *>(IDNA::createUTS46Instance(options, *pErrorCode));
1329 }
1330 
1331 U_CAPI void U_EXPORT2
uidna_close(UIDNA * idna)1332 uidna_close(UIDNA *idna) {
1333     delete reinterpret_cast<IDNA *>(idna);
1334 }
1335 
1336 static UBool
checkArgs(const void * label,int32_t length,void * dest,int32_t capacity,UIDNAInfo * pInfo,UErrorCode * pErrorCode)1337 checkArgs(const void *label, int32_t length,
1338           void *dest, int32_t capacity,
1339           UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1340     if(U_FAILURE(*pErrorCode)) {
1341         return FALSE;
1342     }
1343     // sizeof(UIDNAInfo)=16 in the first API version.
1344     if(pInfo==NULL || pInfo->size<16) {
1345         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
1346         return FALSE;
1347     }
1348     if( (label==NULL ? length!=0 : length<-1) ||
1349         (dest==NULL ? capacity!=0 : capacity<0) ||
1350         (dest==label && label!=NULL)
1351     ) {
1352         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
1353         return FALSE;
1354     }
1355     // Set all *pInfo bytes to 0 except for the size field itself.
1356     uprv_memset(&pInfo->size+1, 0, pInfo->size-sizeof(pInfo->size));
1357     return TRUE;
1358 }
1359 
1360 static void
idnaInfoToStruct(IDNAInfo & info,UIDNAInfo * pInfo)1361 idnaInfoToStruct(IDNAInfo &info, UIDNAInfo *pInfo) {
1362     pInfo->isTransitionalDifferent=info.isTransitionalDifferent();
1363     pInfo->errors=info.getErrors();
1364 }
1365 
1366 U_CAPI int32_t U_EXPORT2
uidna_labelToASCII(const UIDNA * idna,const UChar * label,int32_t length,UChar * dest,int32_t capacity,UIDNAInfo * pInfo,UErrorCode * pErrorCode)1367 uidna_labelToASCII(const UIDNA *idna,
1368                    const UChar *label, int32_t length,
1369                    UChar *dest, int32_t capacity,
1370                    UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1371     if(!checkArgs(label, length, dest, capacity, pInfo, pErrorCode)) {
1372         return 0;
1373     }
1374     UnicodeString src((UBool)(length<0), label, length);
1375     UnicodeString destString(dest, 0, capacity);
1376     IDNAInfo info;
1377     reinterpret_cast<const IDNA *>(idna)->labelToASCII(src, destString, info, *pErrorCode);
1378     idnaInfoToStruct(info, pInfo);
1379     return destString.extract(dest, capacity, *pErrorCode);
1380 }
1381 
1382 U_CAPI int32_t U_EXPORT2
uidna_labelToUnicode(const UIDNA * idna,const UChar * label,int32_t length,UChar * dest,int32_t capacity,UIDNAInfo * pInfo,UErrorCode * pErrorCode)1383 uidna_labelToUnicode(const UIDNA *idna,
1384                      const UChar *label, int32_t length,
1385                      UChar *dest, int32_t capacity,
1386                      UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1387     if(!checkArgs(label, length, dest, capacity, pInfo, pErrorCode)) {
1388         return 0;
1389     }
1390     UnicodeString src((UBool)(length<0), label, length);
1391     UnicodeString destString(dest, 0, capacity);
1392     IDNAInfo info;
1393     reinterpret_cast<const IDNA *>(idna)->labelToUnicode(src, destString, info, *pErrorCode);
1394     idnaInfoToStruct(info, pInfo);
1395     return destString.extract(dest, capacity, *pErrorCode);
1396 }
1397 
1398 U_CAPI int32_t U_EXPORT2
uidna_nameToASCII(const UIDNA * idna,const UChar * name,int32_t length,UChar * dest,int32_t capacity,UIDNAInfo * pInfo,UErrorCode * pErrorCode)1399 uidna_nameToASCII(const UIDNA *idna,
1400                   const UChar *name, int32_t length,
1401                   UChar *dest, int32_t capacity,
1402                   UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1403     if(!checkArgs(name, length, dest, capacity, pInfo, pErrorCode)) {
1404         return 0;
1405     }
1406     UnicodeString src((UBool)(length<0), name, length);
1407     UnicodeString destString(dest, 0, capacity);
1408     IDNAInfo info;
1409     reinterpret_cast<const IDNA *>(idna)->nameToASCII(src, destString, info, *pErrorCode);
1410     idnaInfoToStruct(info, pInfo);
1411     return destString.extract(dest, capacity, *pErrorCode);
1412 }
1413 
1414 U_CAPI int32_t U_EXPORT2
uidna_nameToUnicode(const UIDNA * idna,const UChar * name,int32_t length,UChar * dest,int32_t capacity,UIDNAInfo * pInfo,UErrorCode * pErrorCode)1415 uidna_nameToUnicode(const UIDNA *idna,
1416                     const UChar *name, int32_t length,
1417                     UChar *dest, int32_t capacity,
1418                     UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1419     if(!checkArgs(name, length, dest, capacity, pInfo, pErrorCode)) {
1420         return 0;
1421     }
1422     UnicodeString src((UBool)(length<0), name, length);
1423     UnicodeString destString(dest, 0, capacity);
1424     IDNAInfo info;
1425     reinterpret_cast<const IDNA *>(idna)->nameToUnicode(src, destString, info, *pErrorCode);
1426     idnaInfoToStruct(info, pInfo);
1427     return destString.extract(dest, capacity, *pErrorCode);
1428 }
1429 
1430 U_CAPI int32_t U_EXPORT2
uidna_labelToASCII_UTF8(const UIDNA * idna,const char * label,int32_t length,char * dest,int32_t capacity,UIDNAInfo * pInfo,UErrorCode * pErrorCode)1431 uidna_labelToASCII_UTF8(const UIDNA *idna,
1432                         const char *label, int32_t length,
1433                         char *dest, int32_t capacity,
1434                         UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1435     if(!checkArgs(label, length, dest, capacity, pInfo, pErrorCode)) {
1436         return 0;
1437     }
1438     StringPiece src(label, length<0 ? static_cast<int32_t>(uprv_strlen(label)) : length);
1439     CheckedArrayByteSink sink(dest, capacity);
1440     IDNAInfo info;
1441     reinterpret_cast<const IDNA *>(idna)->labelToASCII_UTF8(src, sink, info, *pErrorCode);
1442     idnaInfoToStruct(info, pInfo);
1443     return u_terminateChars(dest, capacity, sink.NumberOfBytesAppended(), pErrorCode);
1444 }
1445 
1446 U_CAPI int32_t U_EXPORT2
uidna_labelToUnicodeUTF8(const UIDNA * idna,const char * label,int32_t length,char * dest,int32_t capacity,UIDNAInfo * pInfo,UErrorCode * pErrorCode)1447 uidna_labelToUnicodeUTF8(const UIDNA *idna,
1448                          const char *label, int32_t length,
1449                          char *dest, int32_t capacity,
1450                          UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1451     if(!checkArgs(label, length, dest, capacity, pInfo, pErrorCode)) {
1452         return 0;
1453     }
1454     StringPiece src(label, length<0 ? static_cast<int32_t>(uprv_strlen(label)) : length);
1455     CheckedArrayByteSink sink(dest, capacity);
1456     IDNAInfo info;
1457     reinterpret_cast<const IDNA *>(idna)->labelToUnicodeUTF8(src, sink, info, *pErrorCode);
1458     idnaInfoToStruct(info, pInfo);
1459     return u_terminateChars(dest, capacity, sink.NumberOfBytesAppended(), pErrorCode);
1460 }
1461 
1462 U_CAPI int32_t U_EXPORT2
uidna_nameToASCII_UTF8(const UIDNA * idna,const char * name,int32_t length,char * dest,int32_t capacity,UIDNAInfo * pInfo,UErrorCode * pErrorCode)1463 uidna_nameToASCII_UTF8(const UIDNA *idna,
1464                        const char *name, int32_t length,
1465                        char *dest, int32_t capacity,
1466                        UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1467     if(!checkArgs(name, length, dest, capacity, pInfo, pErrorCode)) {
1468         return 0;
1469     }
1470     StringPiece src(name, length<0 ? static_cast<int32_t>(uprv_strlen(name)) : length);
1471     CheckedArrayByteSink sink(dest, capacity);
1472     IDNAInfo info;
1473     reinterpret_cast<const IDNA *>(idna)->nameToASCII_UTF8(src, sink, info, *pErrorCode);
1474     idnaInfoToStruct(info, pInfo);
1475     return u_terminateChars(dest, capacity, sink.NumberOfBytesAppended(), pErrorCode);
1476 }
1477 
1478 U_CAPI int32_t U_EXPORT2
uidna_nameToUnicodeUTF8(const UIDNA * idna,const char * name,int32_t length,char * dest,int32_t capacity,UIDNAInfo * pInfo,UErrorCode * pErrorCode)1479 uidna_nameToUnicodeUTF8(const UIDNA *idna,
1480                         const char *name, int32_t length,
1481                         char *dest, int32_t capacity,
1482                         UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1483     if(!checkArgs(name, length, dest, capacity, pInfo, pErrorCode)) {
1484         return 0;
1485     }
1486     StringPiece src(name, length<0 ? static_cast<int32_t>(uprv_strlen(name)) : length);
1487     CheckedArrayByteSink sink(dest, capacity);
1488     IDNAInfo info;
1489     reinterpret_cast<const IDNA *>(idna)->nameToUnicodeUTF8(src, sink, info, *pErrorCode);
1490     idnaInfoToStruct(info, pInfo);
1491     return u_terminateChars(dest, capacity, sink.NumberOfBytesAppended(), pErrorCode);
1492 }
1493 
1494 #endif  // UCONFIG_NO_IDNA
1495