1/*
2*******************************************************************************
3*   Copyright (C) 2010-2014, International Business Machines
4*   Corporation and others.  All Rights Reserved.
5*******************************************************************************
6*   file name:  uts46.cpp
7*   encoding:   US-ASCII
8*   tab size:   8 (not used)
9*   indentation:4
10*
11*   created on: 2010mar09
12*   created by: Markus W. Scherer
13*/
14
15#include "unicode/utypes.h"
16
17#if !UCONFIG_NO_IDNA
18
19#include "unicode/idna.h"
20#include "unicode/normalizer2.h"
21#include "unicode/uscript.h"
22#include "unicode/ustring.h"
23#include "unicode/utf16.h"
24#include "cmemory.h"
25#include "cstring.h"
26#include "punycode.h"
27#include "ubidi_props.h"
28#include "ustr_imp.h"
29
30#define LENGTHOF(array) (int32_t)(sizeof(array)/sizeof((array)[0]))
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
40U_NAMESPACE_BEGIN
41
42// Severe errors which usually result in a U+FFFD replacement character in the result string.
43const 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
50static inline UBool
51isASCIIString(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
62static UBool
63isASCIIOkBiDi(const UChar *s, int32_t length);
64
65static UBool
66isASCIIOkBiDi(const char *s, int32_t length);
67
68// IDNA class default implementations -------------------------------------- ***
69
70IDNA::~IDNA() {}
71
72void
73IDNA::labelToASCII_UTF8(const 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
82void
83IDNA::labelToUnicodeUTF8(const 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
92void
93IDNA::nameToASCII_UTF8(const 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
102void
103IDNA::nameToUnicodeUTF8(const 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
114class UTS46 : public IDNA {
115public:
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(const StringPiece &label, ByteSink &dest,
137                      IDNAInfo &info, UErrorCode &errorCode) const;
138
139    virtual void
140    labelToUnicodeUTF8(const StringPiece &label, ByteSink &dest,
141                       IDNAInfo &info, UErrorCode &errorCode) const;
142
143    virtual void
144    nameToASCII_UTF8(const StringPiece &name, ByteSink &dest,
145                     IDNAInfo &info, UErrorCode &errorCode) const;
146
147    virtual void
148    nameToUnicodeUTF8(const StringPiece &name, ByteSink &dest,
149                      IDNAInfo &info, UErrorCode &errorCode) const;
150
151private:
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(const 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) 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
200IDNA *
201IDNA::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
218UTS46::UTS46(uint32_t opt, UErrorCode &errorCode)
219        : uts46Norm2(*Normalizer2::getInstance(NULL, "uts46", UNORM2_COMPOSE, errorCode)),
220          options(opt) {}
221
222UTS46::~UTS46() {}
223
224UnicodeString &
225UTS46::labelToASCII(const UnicodeString &label, UnicodeString &dest,
226                    IDNAInfo &info, UErrorCode &errorCode) const {
227    return process(label, TRUE, TRUE, dest, info, errorCode);
228}
229
230UnicodeString &
231UTS46::labelToUnicode(const UnicodeString &label, UnicodeString &dest,
232                      IDNAInfo &info, UErrorCode &errorCode) const {
233    return process(label, TRUE, FALSE, dest, info, errorCode);
234}
235
236UnicodeString &
237UTS46::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
249UnicodeString &
250UTS46::nameToUnicode(const UnicodeString &name, UnicodeString &dest,
251                     IDNAInfo &info, UErrorCode &errorCode) const {
252    return process(name, FALSE, FALSE, dest, info, errorCode);
253}
254
255void
256UTS46::labelToASCII_UTF8(const StringPiece &label, ByteSink &dest,
257                         IDNAInfo &info, UErrorCode &errorCode) const {
258    processUTF8(label, TRUE, TRUE, dest, info, errorCode);
259}
260
261void
262UTS46::labelToUnicodeUTF8(const StringPiece &label, ByteSink &dest,
263                          IDNAInfo &info, UErrorCode &errorCode) const {
264    processUTF8(label, TRUE, FALSE, dest, info, errorCode);
265}
266
267void
268UTS46::nameToASCII_UTF8(const StringPiece &name, ByteSink &dest,
269                        IDNAInfo &info, UErrorCode &errorCode) const {
270    processUTF8(name, FALSE, TRUE, dest, info, errorCode);
271}
272
273void
274UTS46::nameToUnicodeUTF8(const 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)
286static 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
301UnicodeString &
302UTS46::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        if(toASCII) {
325            info.errors|=UIDNA_ERROR_EMPTY_LABEL;
326        }
327        return dest;
328    }
329    UChar *destArray=dest.getBuffer(srcLength);
330    if(destArray==NULL) {
331        errorCode=U_MEMORY_ALLOCATION_ERROR;
332        return dest;
333    }
334    // ASCII fastpath
335    UBool disallowNonLDHDot=(options&UIDNA_USE_STD3_RULES)!=0;
336    int32_t labelStart=0;
337    int32_t i;
338    for(i=0;; ++i) {
339        if(i==srcLength) {
340            if(toASCII) {
341                if((i-labelStart)>63) {
342                    info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
343                }
344                // There is a trailing dot if labelStart==i.
345                if(!isLabel && i>=254 && (i>254 || labelStart<i)) {
346                    info.errors|=UIDNA_ERROR_DOMAIN_NAME_TOO_LONG;
347                }
348            }
349            info.errors|=info.labelErrors;
350            dest.releaseBuffer(i);
351            return dest;
352        }
353        UChar c=srcArray[i];
354        if(c>0x7f) {
355            break;
356        }
357        int cData=asciiData[c];
358        if(cData>0) {
359            destArray[i]=c+0x20;  // Lowercase an uppercase ASCII letter.
360        } else if(cData<0 && disallowNonLDHDot) {
361            break;  // Replacing with U+FFFD can be complicated for toASCII.
362        } else {
363            destArray[i]=c;
364            if(c==0x2d) {  // hyphen
365                if(i==(labelStart+3) && srcArray[i-1]==0x2d) {
366                    // "??--..." is Punycode or forbidden.
367                    ++i;  // '-' was copied to dest already
368                    break;
369                }
370                if(i==labelStart) {
371                    // label starts with "-"
372                    info.labelErrors|=UIDNA_ERROR_LEADING_HYPHEN;
373                }
374                if((i+1)==srcLength || srcArray[i+1]==0x2e) {
375                    // label ends with "-"
376                    info.labelErrors|=UIDNA_ERROR_TRAILING_HYPHEN;
377                }
378            } else if(c==0x2e) {  // dot
379                if(isLabel) {
380                    // Replacing with U+FFFD can be complicated for toASCII.
381                    ++i;  // '.' was copied to dest already
382                    break;
383                }
384                if(toASCII) {
385                    if(i==labelStart) {
386                        info.labelErrors|=UIDNA_ERROR_EMPTY_LABEL;
387                    } else if((i-labelStart)>63) {
388                        info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
389                    }
390                }
391                info.errors|=info.labelErrors;
392                info.labelErrors=0;
393                labelStart=i+1;
394            }
395        }
396    }
397    info.errors|=info.labelErrors;
398    dest.releaseBuffer(i);
399    processUnicode(src, labelStart, i, isLabel, toASCII, dest, info, errorCode);
400    if( info.isBiDi && U_SUCCESS(errorCode) && (info.errors&severeErrors)==0 &&
401        (!info.isOkBiDi || (labelStart>0 && !isASCIIOkBiDi(dest.getBuffer(), labelStart)))
402    ) {
403        info.errors|=UIDNA_ERROR_BIDI;
404    }
405    return dest;
406}
407
408void
409UTS46::processUTF8(const StringPiece &src,
410                   UBool isLabel, UBool toASCII,
411                   ByteSink &dest,
412                   IDNAInfo &info, UErrorCode &errorCode) const {
413    if(U_FAILURE(errorCode)) {
414        return;
415    }
416    const char *srcArray=src.data();
417    int32_t srcLength=src.length();
418    if(srcArray==NULL && srcLength!=0) {
419        errorCode=U_ILLEGAL_ARGUMENT_ERROR;
420        return;
421    }
422    // Arguments are fine, reset output values.
423    info.reset();
424    if(srcLength==0) {
425        if(toASCII) {
426            info.errors|=UIDNA_ERROR_EMPTY_LABEL;
427        }
428        dest.Flush();
429        return;
430    }
431    UnicodeString destString;
432    int32_t labelStart=0;
433    if(srcLength<=256) {  // length of stackArray[]
434        // ASCII fastpath
435        char stackArray[256];
436        int32_t destCapacity;
437        char *destArray=dest.GetAppendBuffer(srcLength, srcLength+20,
438                                             stackArray, LENGTHOF(stackArray), &destCapacity);
439        UBool disallowNonLDHDot=(options&UIDNA_USE_STD3_RULES)!=0;
440        int32_t i;
441        for(i=0;; ++i) {
442            if(i==srcLength) {
443                if(toASCII) {
444                    if((i-labelStart)>63) {
445                        info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
446                    }
447                    // There is a trailing dot if labelStart==i.
448                    if(!isLabel && i>=254 && (i>254 || labelStart<i)) {
449                        info.errors|=UIDNA_ERROR_DOMAIN_NAME_TOO_LONG;
450                    }
451                }
452                info.errors|=info.labelErrors;
453                dest.Append(destArray, i);
454                dest.Flush();
455                return;
456            }
457            char c=srcArray[i];
458            if((int8_t)c<0) {  // (uint8_t)c>0x7f
459                break;
460            }
461            int cData=asciiData[(int)c];  // Cast: gcc warns about indexing with a char.
462            if(cData>0) {
463                destArray[i]=c+0x20;  // Lowercase an uppercase ASCII letter.
464            } else if(cData<0 && disallowNonLDHDot) {
465                break;  // Replacing with U+FFFD can be complicated for toASCII.
466            } else {
467                destArray[i]=c;
468                if(c==0x2d) {  // hyphen
469                    if(i==(labelStart+3) && srcArray[i-1]==0x2d) {
470                        // "??--..." is Punycode or forbidden.
471                        break;
472                    }
473                    if(i==labelStart) {
474                        // label starts with "-"
475                        info.labelErrors|=UIDNA_ERROR_LEADING_HYPHEN;
476                    }
477                    if((i+1)==srcLength || srcArray[i+1]==0x2e) {
478                        // label ends with "-"
479                        info.labelErrors|=UIDNA_ERROR_TRAILING_HYPHEN;
480                    }
481                } else if(c==0x2e) {  // dot
482                    if(isLabel) {
483                        break;  // Replacing with U+FFFD can be complicated for toASCII.
484                    }
485                    if(toASCII) {
486                        if(i==labelStart) {
487                            info.labelErrors|=UIDNA_ERROR_EMPTY_LABEL;
488                        } else if((i-labelStart)>63) {
489                            info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
490                        }
491                    }
492                    info.errors|=info.labelErrors;
493                    info.labelErrors=0;
494                    labelStart=i+1;
495                }
496            }
497        }
498        info.errors|=info.labelErrors;
499        // Convert the processed ASCII prefix of the current label to UTF-16.
500        int32_t mappingStart=i-labelStart;
501        destString=UnicodeString::fromUTF8(StringPiece(destArray+labelStart, mappingStart));
502        // Output the previous ASCII labels and process the rest of src in UTF-16.
503        dest.Append(destArray, labelStart);
504        processUnicode(UnicodeString::fromUTF8(StringPiece(src, labelStart)), 0, mappingStart,
505                       isLabel, toASCII,
506                       destString, info, errorCode);
507    } else {
508        // src is too long for the ASCII fastpath implementation.
509        processUnicode(UnicodeString::fromUTF8(src), 0, 0,
510                       isLabel, toASCII,
511                       destString, info, errorCode);
512    }
513    destString.toUTF8(dest);  // calls dest.Flush()
514    if(toASCII && !isLabel) {
515        // length==labelStart==254 means that there is a trailing dot (ok) and
516        // destString is empty (do not index at 253-labelStart).
517        int32_t length=labelStart+destString.length();
518        if( length>=254 && isASCIIString(destString) &&
519            (length>254 ||
520             (labelStart<254 && destString[253-labelStart]!=0x2e))
521        ) {
522            info.errors|=UIDNA_ERROR_DOMAIN_NAME_TOO_LONG;
523        }
524    }
525    if( info.isBiDi && U_SUCCESS(errorCode) && (info.errors&severeErrors)==0 &&
526        (!info.isOkBiDi || (labelStart>0 && !isASCIIOkBiDi(srcArray, labelStart)))
527    ) {
528        info.errors|=UIDNA_ERROR_BIDI;
529    }
530}
531
532UnicodeString &
533UTS46::processUnicode(const UnicodeString &src,
534                      int32_t labelStart, int32_t mappingStart,
535                      UBool isLabel, UBool toASCII,
536                      UnicodeString &dest,
537                      IDNAInfo &info, UErrorCode &errorCode) const {
538    if(mappingStart==0) {
539        uts46Norm2.normalize(src, dest, errorCode);
540    } else {
541        uts46Norm2.normalizeSecondAndAppend(dest, src.tempSubString(mappingStart), errorCode);
542    }
543    if(U_FAILURE(errorCode)) {
544        return dest;
545    }
546    UBool doMapDevChars=
547        toASCII ? (options&UIDNA_NONTRANSITIONAL_TO_ASCII)==0 :
548                  (options&UIDNA_NONTRANSITIONAL_TO_UNICODE)==0;
549    const UChar *destArray=dest.getBuffer();
550    int32_t destLength=dest.length();
551    int32_t labelLimit=labelStart;
552    while(labelLimit<destLength) {
553        UChar c=destArray[labelLimit];
554        if(c==0x2e && !isLabel) {
555            int32_t labelLength=labelLimit-labelStart;
556            int32_t newLength=processLabel(dest, labelStart, labelLength,
557                                            toASCII, info, errorCode);
558            info.errors|=info.labelErrors;
559            info.labelErrors=0;
560            if(U_FAILURE(errorCode)) {
561                return dest;
562            }
563            destArray=dest.getBuffer();
564            destLength+=newLength-labelLength;
565            labelLimit=labelStart+=newLength+1;
566        } else if(0xdf<=c && c<=0x200d && (c==0xdf || c==0x3c2 || c>=0x200c)) {
567            info.isTransDiff=TRUE;
568            if(doMapDevChars) {
569                destLength=mapDevChars(dest, labelStart, labelLimit, errorCode);
570                if(U_FAILURE(errorCode)) {
571                    return dest;
572                }
573                destArray=dest.getBuffer();
574                // Do not increment labelLimit in case c was removed.
575                // All deviation characters have been mapped, no need to check for them again.
576                doMapDevChars=FALSE;
577            } else {
578                ++labelLimit;
579            }
580        } else {
581            ++labelLimit;
582        }
583    }
584    // Permit an empty label at the end (0<labelStart==labelLimit==destLength is ok)
585    // but not an empty label elsewhere nor a completely empty domain name.
586    // processLabel() sets UIDNA_ERROR_EMPTY_LABEL when labelLength==0.
587    if(0==labelStart || labelStart<labelLimit) {
588        processLabel(dest, labelStart, labelLimit-labelStart,
589                      toASCII, info, errorCode);
590        info.errors|=info.labelErrors;
591    }
592    return dest;
593}
594
595int32_t
596UTS46::mapDevChars(UnicodeString &dest, int32_t labelStart, int32_t mappingStart,
597                   UErrorCode &errorCode) const {
598    int32_t length=dest.length();
599    UChar *s=dest.getBuffer(dest[mappingStart]==0xdf ? length+1 : length);
600    if(s==NULL) {
601        errorCode=U_MEMORY_ALLOCATION_ERROR;
602        return length;
603    }
604    int32_t capacity=dest.getCapacity();
605    UBool didMapDevChars=FALSE;
606    int32_t readIndex=mappingStart, writeIndex=mappingStart;
607    do {
608        UChar c=s[readIndex++];
609        switch(c) {
610        case 0xdf:
611            // Map sharp s to ss.
612            didMapDevChars=TRUE;
613            s[writeIndex++]=0x73;  // Replace sharp s with first s.
614            // Insert second s and account for possible buffer reallocation.
615            if(writeIndex==readIndex) {
616                if(length==capacity) {
617                    dest.releaseBuffer(length);
618                    s=dest.getBuffer(length+1);
619                    if(s==NULL) {
620                        errorCode=U_MEMORY_ALLOCATION_ERROR;
621                        return length;
622                    }
623                    capacity=dest.getCapacity();
624                }
625                u_memmove(s+writeIndex+1, s+writeIndex, length-writeIndex);
626                ++readIndex;
627            }
628            s[writeIndex++]=0x73;
629            ++length;
630            break;
631        case 0x3c2:  // Map final sigma to nonfinal sigma.
632            didMapDevChars=TRUE;
633            s[writeIndex++]=0x3c3;
634            break;
635        case 0x200c:  // Ignore/remove ZWNJ.
636        case 0x200d:  // Ignore/remove ZWJ.
637            didMapDevChars=TRUE;
638            --length;
639            break;
640        default:
641            // Only really necessary if writeIndex was different from readIndex.
642            s[writeIndex++]=c;
643            break;
644        }
645    } while(writeIndex<length);
646    dest.releaseBuffer(length);
647    if(didMapDevChars) {
648        // Mapping deviation characters might have resulted in an un-NFC string.
649        // We could use either the NFC or the UTS #46 normalizer.
650        // By using the UTS #46 normalizer again, we avoid having to load a second .nrm data file.
651        UnicodeString normalized;
652        uts46Norm2.normalize(dest.tempSubString(labelStart), normalized, errorCode);
653        if(U_SUCCESS(errorCode)) {
654            dest.replace(labelStart, 0x7fffffff, normalized);
655            return dest.length();
656        }
657    }
658    return length;
659}
660
661// Some non-ASCII characters are equivalent to sequences with
662// non-LDH ASCII characters. To find them:
663// grep disallowed_STD3_valid IdnaMappingTable.txt (or uts46.txt)
664static inline UBool
665isNonASCIIDisallowedSTD3Valid(UChar32 c) {
666    return c==0x2260 || c==0x226E || c==0x226F;
667}
668
669// Replace the label in dest with the label string, if the label was modified.
670// If &label==&dest then the label was modified in-place and labelLength
671// is the new label length, different from label.length().
672// If &label!=&dest then labelLength==label.length().
673// Returns labelLength (= the new label length).
674static int32_t
675replaceLabel(UnicodeString &dest, int32_t destLabelStart, int32_t destLabelLength,
676             const UnicodeString &label, int32_t labelLength) {
677    if(&label!=&dest) {
678        dest.replace(destLabelStart, destLabelLength, label);
679    }
680    return labelLength;
681}
682
683int32_t
684UTS46::processLabel(UnicodeString &dest,
685                    int32_t labelStart, int32_t labelLength,
686                    UBool toASCII,
687                    IDNAInfo &info, UErrorCode &errorCode) const {
688    UnicodeString fromPunycode;
689    UnicodeString *labelString;
690    const UChar *label=dest.getBuffer()+labelStart;
691    int32_t destLabelStart=labelStart;
692    int32_t destLabelLength=labelLength;
693    UBool wasPunycode;
694    if(labelLength>=4 && label[0]==0x78 && label[1]==0x6e && label[2]==0x2d && label[3]==0x2d) {
695        // Label starts with "xn--", try to un-Punycode it.
696        wasPunycode=TRUE;
697        UChar *unicodeBuffer=fromPunycode.getBuffer(-1);  // capacity==-1: most labels should fit
698        if(unicodeBuffer==NULL) {
699            // Should never occur if we used capacity==-1 which uses the internal buffer.
700            errorCode=U_MEMORY_ALLOCATION_ERROR;
701            return labelLength;
702        }
703        UErrorCode punycodeErrorCode=U_ZERO_ERROR;
704        int32_t unicodeLength=u_strFromPunycode(label+4, labelLength-4,
705                                                unicodeBuffer, fromPunycode.getCapacity(),
706                                                NULL, &punycodeErrorCode);
707        if(punycodeErrorCode==U_BUFFER_OVERFLOW_ERROR) {
708            fromPunycode.releaseBuffer(0);
709            unicodeBuffer=fromPunycode.getBuffer(unicodeLength);
710            if(unicodeBuffer==NULL) {
711                errorCode=U_MEMORY_ALLOCATION_ERROR;
712                return labelLength;
713            }
714            punycodeErrorCode=U_ZERO_ERROR;
715            unicodeLength=u_strFromPunycode(label+4, labelLength-4,
716                                            unicodeBuffer, fromPunycode.getCapacity(),
717                                            NULL, &punycodeErrorCode);
718        }
719        fromPunycode.releaseBuffer(unicodeLength);
720        if(U_FAILURE(punycodeErrorCode)) {
721            info.labelErrors|=UIDNA_ERROR_PUNYCODE;
722            return markBadACELabel(dest, labelStart, labelLength, toASCII, info);
723        }
724        // Check for NFC, and for characters that are not
725        // valid or deviation characters according to the normalizer.
726        // If there is something wrong, then the string will change.
727        // Note that the normalizer passes through non-LDH ASCII and deviation characters.
728        // Deviation characters are ok in Punycode even in transitional processing.
729        // In the code further below, if we find non-LDH ASCII and we have UIDNA_USE_STD3_RULES
730        // then we will set UIDNA_ERROR_INVALID_ACE_LABEL there too.
731        UBool isValid=uts46Norm2.isNormalized(fromPunycode, errorCode);
732        if(U_FAILURE(errorCode)) {
733            return labelLength;
734        }
735        if(!isValid) {
736            info.labelErrors|=UIDNA_ERROR_INVALID_ACE_LABEL;
737            return markBadACELabel(dest, labelStart, labelLength, toASCII, info);
738        }
739        labelString=&fromPunycode;
740        label=fromPunycode.getBuffer();
741        labelStart=0;
742        labelLength=fromPunycode.length();
743    } else {
744        wasPunycode=FALSE;
745        labelString=&dest;
746    }
747    // Validity check
748    if(labelLength==0) {
749        if(toASCII) {
750            info.labelErrors|=UIDNA_ERROR_EMPTY_LABEL;
751        }
752        return replaceLabel(dest, destLabelStart, destLabelLength, *labelString, labelLength);
753    }
754    // labelLength>0
755    if(labelLength>=4 && label[2]==0x2d && label[3]==0x2d) {
756        // label starts with "??--"
757        info.labelErrors|=UIDNA_ERROR_HYPHEN_3_4;
758    }
759    if(label[0]==0x2d) {
760        // label starts with "-"
761        info.labelErrors|=UIDNA_ERROR_LEADING_HYPHEN;
762    }
763    if(label[labelLength-1]==0x2d) {
764        // label ends with "-"
765        info.labelErrors|=UIDNA_ERROR_TRAILING_HYPHEN;
766    }
767    // If the label was not a Punycode label, then it was the result of
768    // mapping, normalization and label segmentation.
769    // If the label was in Punycode, then we mapped it again above
770    // and checked its validity.
771    // Now we handle the STD3 restriction to LDH characters (if set)
772    // and we look for U+FFFD which indicates disallowed characters
773    // in a non-Punycode label or U+FFFD itself in a Punycode label.
774    // We also check for dots which can come from the input to a single-label function.
775    // Ok to cast away const because we own the UnicodeString.
776    UChar *s=(UChar *)label;
777    const UChar *limit=label+labelLength;
778    UChar oredChars=0;
779    // If we enforce STD3 rules, then ASCII characters other than LDH and dot are disallowed.
780    UBool disallowNonLDHDot=(options&UIDNA_USE_STD3_RULES)!=0;
781    do {
782        UChar c=*s;
783        if(c<=0x7f) {
784            if(c==0x2e) {
785                info.labelErrors|=UIDNA_ERROR_LABEL_HAS_DOT;
786                *s=0xfffd;
787            } else if(disallowNonLDHDot && asciiData[c]<0) {
788                info.labelErrors|=UIDNA_ERROR_DISALLOWED;
789                *s=0xfffd;
790            }
791        } else {
792            oredChars|=c;
793            if(disallowNonLDHDot && isNonASCIIDisallowedSTD3Valid(c)) {
794                info.labelErrors|=UIDNA_ERROR_DISALLOWED;
795                *s=0xfffd;
796            } else if(c==0xfffd) {
797                info.labelErrors|=UIDNA_ERROR_DISALLOWED;
798            }
799        }
800        ++s;
801    } while(s<limit);
802    // Check for a leading combining mark after other validity checks
803    // so that we don't report UIDNA_ERROR_DISALLOWED for the U+FFFD from here.
804    UChar32 c;
805    int32_t cpLength=0;
806    // "Unsafe" is ok because unpaired surrogates were mapped to U+FFFD.
807    U16_NEXT_UNSAFE(label, cpLength, c);
808    if((U_GET_GC_MASK(c)&U_GC_M_MASK)!=0) {
809        info.labelErrors|=UIDNA_ERROR_LEADING_COMBINING_MARK;
810        labelString->replace(labelStart, cpLength, (UChar)0xfffd);
811        label=labelString->getBuffer()+labelStart;
812        labelLength+=1-cpLength;
813        if(labelString==&dest) {
814            destLabelLength=labelLength;
815        }
816    }
817    if((info.labelErrors&severeErrors)==0) {
818        // Do contextual checks only if we do not have U+FFFD from a severe error
819        // because U+FFFD can make these checks fail.
820        if((options&UIDNA_CHECK_BIDI)!=0 && (!info.isBiDi || info.isOkBiDi)) {
821            checkLabelBiDi(label, labelLength, info);
822        }
823        if( (options&UIDNA_CHECK_CONTEXTJ)!=0 && (oredChars&0x200c)==0x200c &&
824            !isLabelOkContextJ(label, labelLength)
825        ) {
826            info.labelErrors|=UIDNA_ERROR_CONTEXTJ;
827        }
828        if((options&UIDNA_CHECK_CONTEXTO)!=0 && oredChars>=0xb7) {
829            checkLabelContextO(label, labelLength, info);
830        }
831        if(toASCII) {
832            if(wasPunycode) {
833                // Leave a Punycode label unchanged if it has no severe errors.
834                if(destLabelLength>63) {
835                    info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
836                }
837                return destLabelLength;
838            } else if(oredChars>=0x80) {
839                // Contains non-ASCII characters.
840                UnicodeString punycode;
841                UChar *buffer=punycode.getBuffer(63);  // 63==maximum DNS label length
842                if(buffer==NULL) {
843                    errorCode=U_MEMORY_ALLOCATION_ERROR;
844                    return destLabelLength;
845                }
846                buffer[0]=0x78;  // Write "xn--".
847                buffer[1]=0x6e;
848                buffer[2]=0x2d;
849                buffer[3]=0x2d;
850                int32_t punycodeLength=u_strToPunycode(label, labelLength,
851                                                      buffer+4, punycode.getCapacity()-4,
852                                                      NULL, &errorCode);
853                if(errorCode==U_BUFFER_OVERFLOW_ERROR) {
854                    errorCode=U_ZERO_ERROR;
855                    punycode.releaseBuffer(4);
856                    buffer=punycode.getBuffer(4+punycodeLength);
857                    if(buffer==NULL) {
858                        errorCode=U_MEMORY_ALLOCATION_ERROR;
859                        return destLabelLength;
860                    }
861                    punycodeLength=u_strToPunycode(label, labelLength,
862                                                  buffer+4, punycode.getCapacity()-4,
863                                                  NULL, &errorCode);
864                }
865                punycodeLength+=4;
866                punycode.releaseBuffer(punycodeLength);
867                if(U_FAILURE(errorCode)) {
868                    return destLabelLength;
869                }
870                if(punycodeLength>63) {
871                    info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
872                }
873                return replaceLabel(dest, destLabelStart, destLabelLength,
874                                    punycode, punycodeLength);
875            } else {
876                // all-ASCII label
877                if(labelLength>63) {
878                    info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
879                }
880            }
881        }
882    } else {
883        // If a Punycode label has severe errors,
884        // then leave it but make sure it does not look valid.
885        if(wasPunycode) {
886            info.labelErrors|=UIDNA_ERROR_INVALID_ACE_LABEL;
887            return markBadACELabel(dest, destLabelStart, destLabelLength, toASCII, info);
888        }
889    }
890    return replaceLabel(dest, destLabelStart, destLabelLength, *labelString, labelLength);
891}
892
893// Make sure an ACE label does not look valid.
894// Append U+FFFD if the label has only LDH characters.
895// If UIDNA_USE_STD3_RULES, also replace disallowed ASCII characters with U+FFFD.
896int32_t
897UTS46::markBadACELabel(UnicodeString &dest,
898                       int32_t labelStart, int32_t labelLength,
899                       UBool toASCII, IDNAInfo &info) const {
900    UBool disallowNonLDHDot=(options&UIDNA_USE_STD3_RULES)!=0;
901    UBool isASCII=TRUE;
902    UBool onlyLDH=TRUE;
903    const UChar *label=dest.getBuffer()+labelStart;
904    // Ok to cast away const because we own the UnicodeString.
905    UChar *s=(UChar *)label+4;  // After the initial "xn--".
906    const UChar *limit=label+labelLength;
907    do {
908        UChar c=*s;
909        if(c<=0x7f) {
910            if(c==0x2e) {
911                info.labelErrors|=UIDNA_ERROR_LABEL_HAS_DOT;
912                *s=0xfffd;
913                isASCII=onlyLDH=FALSE;
914            } else if(asciiData[c]<0) {
915                onlyLDH=FALSE;
916                if(disallowNonLDHDot) {
917                    *s=0xfffd;
918                    isASCII=FALSE;
919                }
920            }
921        } else {
922            isASCII=onlyLDH=FALSE;
923        }
924    } while(++s<limit);
925    if(onlyLDH) {
926        dest.insert(labelStart+labelLength, (UChar)0xfffd);
927        ++labelLength;
928    } else {
929        if(toASCII && isASCII && labelLength>63) {
930            info.labelErrors|=UIDNA_ERROR_LABEL_TOO_LONG;
931        }
932    }
933    return labelLength;
934}
935
936const uint32_t L_MASK=U_MASK(U_LEFT_TO_RIGHT);
937const uint32_t R_AL_MASK=U_MASK(U_RIGHT_TO_LEFT)|U_MASK(U_RIGHT_TO_LEFT_ARABIC);
938const uint32_t L_R_AL_MASK=L_MASK|R_AL_MASK;
939
940const uint32_t R_AL_AN_MASK=R_AL_MASK|U_MASK(U_ARABIC_NUMBER);
941
942const uint32_t EN_AN_MASK=U_MASK(U_EUROPEAN_NUMBER)|U_MASK(U_ARABIC_NUMBER);
943const uint32_t R_AL_EN_AN_MASK=R_AL_MASK|EN_AN_MASK;
944const uint32_t L_EN_MASK=L_MASK|U_MASK(U_EUROPEAN_NUMBER);
945
946const uint32_t ES_CS_ET_ON_BN_NSM_MASK=
947    U_MASK(U_EUROPEAN_NUMBER_SEPARATOR)|
948    U_MASK(U_COMMON_NUMBER_SEPARATOR)|
949    U_MASK(U_EUROPEAN_NUMBER_TERMINATOR)|
950    U_MASK(U_OTHER_NEUTRAL)|
951    U_MASK(U_BOUNDARY_NEUTRAL)|
952    U_MASK(U_DIR_NON_SPACING_MARK);
953const uint32_t L_EN_ES_CS_ET_ON_BN_NSM_MASK=L_EN_MASK|ES_CS_ET_ON_BN_NSM_MASK;
954const 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;
955
956// We scan the whole label and check both for whether it contains RTL characters
957// and whether it passes the BiDi Rule.
958// In a BiDi domain name, all labels must pass the BiDi Rule, but we might find
959// that a domain name is a BiDi domain name (has an RTL label) only after
960// processing several earlier labels.
961void
962UTS46::checkLabelBiDi(const UChar *label, int32_t labelLength, IDNAInfo &info) const {
963    // IDNA2008 BiDi rule
964    // Get the directionality of the first character.
965    UChar32 c;
966    int32_t i=0;
967    U16_NEXT_UNSAFE(label, i, c);
968    uint32_t firstMask=U_MASK(u_charDirection(c));
969    // 1. The first character must be a character with BIDI property L, R
970    // or AL.  If it has the R or AL property, it is an RTL label; if it
971    // has the L property, it is an LTR label.
972    if((firstMask&~L_R_AL_MASK)!=0) {
973        info.isOkBiDi=FALSE;
974    }
975    // Get the directionality of the last non-NSM character.
976    uint32_t lastMask;
977    for(;;) {
978        if(i>=labelLength) {
979            lastMask=firstMask;
980            break;
981        }
982        U16_PREV_UNSAFE(label, labelLength, c);
983        UCharDirection dir=u_charDirection(c);
984        if(dir!=U_DIR_NON_SPACING_MARK) {
985            lastMask=U_MASK(dir);
986            break;
987        }
988    }
989    // 3. In an RTL label, the end of the label must be a character with
990    // BIDI property R, AL, EN or AN, followed by zero or more
991    // characters with BIDI property NSM.
992    // 6. In an LTR label, the end of the label must be a character with
993    // BIDI property L or EN, followed by zero or more characters with
994    // BIDI property NSM.
995    if( (firstMask&L_MASK)!=0 ?
996            (lastMask&~L_EN_MASK)!=0 :
997            (lastMask&~R_AL_EN_AN_MASK)!=0
998    ) {
999        info.isOkBiDi=FALSE;
1000    }
1001    // Get the directionalities of the intervening characters.
1002    uint32_t mask=0;
1003    while(i<labelLength) {
1004        U16_NEXT_UNSAFE(label, i, c);
1005        mask|=U_MASK(u_charDirection(c));
1006    }
1007    if(firstMask&L_MASK) {
1008        // 5. In an LTR label, only characters with the BIDI properties L, EN,
1009        // ES, CS, ET, ON, BN and NSM are allowed.
1010        if((mask&~L_EN_ES_CS_ET_ON_BN_NSM_MASK)!=0) {
1011            info.isOkBiDi=FALSE;
1012        }
1013    } else {
1014        // 2. In an RTL label, only characters with the BIDI properties R, AL,
1015        // AN, EN, ES, CS, ET, ON, BN and NSM are allowed.
1016        if((mask&~R_AL_AN_EN_ES_CS_ET_ON_BN_NSM_MASK)!=0) {
1017            info.isOkBiDi=FALSE;
1018        }
1019        // 4. In an RTL label, if an EN is present, no AN may be present, and
1020        // vice versa.
1021        if((mask&EN_AN_MASK)==EN_AN_MASK) {
1022            info.isOkBiDi=FALSE;
1023        }
1024    }
1025    // An RTL label is a label that contains at least one character of type
1026    // R, AL or AN. [...]
1027    // A "BIDI domain name" is a domain name that contains at least one RTL
1028    // label. [...]
1029    // The following rule, consisting of six conditions, applies to labels
1030    // in BIDI domain names.
1031    if(((firstMask|mask|lastMask)&R_AL_AN_MASK)!=0) {
1032        info.isBiDi=TRUE;
1033    }
1034}
1035
1036// Special code for the ASCII prefix of a BiDi domain name.
1037// The ASCII prefix is all-LTR.
1038
1039// IDNA2008 BiDi rule, parts relevant to ASCII labels:
1040// 1. The first character must be a character with BIDI property L [...]
1041// 5. In an LTR label, only characters with the BIDI properties L, EN,
1042// ES, CS, ET, ON, BN and NSM are allowed.
1043// 6. In an LTR label, the end of the label must be a character with
1044// BIDI property L or EN [...]
1045
1046// UTF-16 version, called for mapped ASCII prefix.
1047// Cannot contain uppercase A-Z.
1048// s[length-1] must be the trailing dot.
1049static UBool
1050isASCIIOkBiDi(const UChar *s, int32_t length) {
1051    int32_t labelStart=0;
1052    for(int32_t i=0; i<length; ++i) {
1053        UChar c=s[i];
1054        if(c==0x2e) {  // dot
1055            if(i>labelStart) {
1056                c=s[i-1];
1057                if(!(0x61<=c && c<=0x7a) && !(0x30<=c && c<=0x39)) {
1058                    // Last character in the label is not an L or EN.
1059                    return FALSE;
1060                }
1061            }
1062            labelStart=i+1;
1063        } else if(i==labelStart) {
1064            if(!(0x61<=c && c<=0x7a)) {
1065                // First character in the label is not an L.
1066                return FALSE;
1067            }
1068        } else {
1069            if(c<=0x20 && (c>=0x1c || (9<=c && c<=0xd))) {
1070                // Intermediate character in the label is a B, S or WS.
1071                return FALSE;
1072            }
1073        }
1074    }
1075    return TRUE;
1076}
1077
1078// UTF-8 version, called for source ASCII prefix.
1079// Can contain uppercase A-Z.
1080// s[length-1] must be the trailing dot.
1081static UBool
1082isASCIIOkBiDi(const char *s, int32_t length) {
1083    int32_t labelStart=0;
1084    for(int32_t i=0; i<length; ++i) {
1085        char c=s[i];
1086        if(c==0x2e) {  // dot
1087            if(i>labelStart) {
1088                c=s[i-1];
1089                if(!(0x61<=c && c<=0x7a) && !(0x41<=c && c<=0x5a) && !(0x30<=c && c<=0x39)) {
1090                    // Last character in the label is not an L or EN.
1091                    return FALSE;
1092                }
1093            }
1094            labelStart=i+1;
1095        } else if(i==labelStart) {
1096            if(!(0x61<=c && c<=0x7a) && !(0x41<=c && c<=0x5a)) {
1097                // First character in the label is not an L.
1098                return FALSE;
1099            }
1100        } else {
1101            if(c<=0x20 && (c>=0x1c || (9<=c && c<=0xd))) {
1102                // Intermediate character in the label is a B, S or WS.
1103                return FALSE;
1104            }
1105        }
1106    }
1107    return TRUE;
1108}
1109
1110UBool
1111UTS46::isLabelOkContextJ(const UChar *label, int32_t labelLength) const {
1112    const UBiDiProps *bdp=ubidi_getSingleton();
1113    // [IDNA2008-Tables]
1114    // 200C..200D  ; CONTEXTJ    # ZERO WIDTH NON-JOINER..ZERO WIDTH JOINER
1115    for(int32_t i=0; i<labelLength; ++i) {
1116        if(label[i]==0x200c) {
1117            // Appendix A.1. ZERO WIDTH NON-JOINER
1118            // Rule Set:
1119            //  False;
1120            //  If Canonical_Combining_Class(Before(cp)) .eq.  Virama Then True;
1121            //  If RegExpMatch((Joining_Type:{L,D})(Joining_Type:T)*\u200C
1122            //     (Joining_Type:T)*(Joining_Type:{R,D})) Then True;
1123            if(i==0) {
1124                return FALSE;
1125            }
1126            UChar32 c;
1127            int32_t j=i;
1128            U16_PREV_UNSAFE(label, j, c);
1129            if(uts46Norm2.getCombiningClass(c)==9) {
1130                continue;
1131            }
1132            // check precontext (Joining_Type:{L,D})(Joining_Type:T)*
1133            for(;;) {
1134                UJoiningType type=ubidi_getJoiningType(bdp, c);
1135                if(type==U_JT_TRANSPARENT) {
1136                    if(j==0) {
1137                        return FALSE;
1138                    }
1139                    U16_PREV_UNSAFE(label, j, c);
1140                } else if(type==U_JT_LEFT_JOINING || type==U_JT_DUAL_JOINING) {
1141                    break;  // precontext fulfilled
1142                } else {
1143                    return FALSE;
1144                }
1145            }
1146            // check postcontext (Joining_Type:T)*(Joining_Type:{R,D})
1147            for(j=i+1;;) {
1148                if(j==labelLength) {
1149                    return FALSE;
1150                }
1151                U16_NEXT_UNSAFE(label, j, c);
1152                UJoiningType type=ubidi_getJoiningType(bdp, c);
1153                if(type==U_JT_TRANSPARENT) {
1154                    // just skip this character
1155                } else if(type==U_JT_RIGHT_JOINING || type==U_JT_DUAL_JOINING) {
1156                    break;  // postcontext fulfilled
1157                } else {
1158                    return FALSE;
1159                }
1160            }
1161        } else if(label[i]==0x200d) {
1162            // Appendix A.2. ZERO WIDTH JOINER (U+200D)
1163            // Rule Set:
1164            //  False;
1165            //  If Canonical_Combining_Class(Before(cp)) .eq.  Virama Then True;
1166            if(i==0) {
1167                return FALSE;
1168            }
1169            UChar32 c;
1170            int32_t j=i;
1171            U16_PREV_UNSAFE(label, j, c);
1172            if(uts46Norm2.getCombiningClass(c)!=9) {
1173                return FALSE;
1174            }
1175        }
1176    }
1177    return TRUE;
1178}
1179
1180void
1181UTS46::checkLabelContextO(const UChar *label, int32_t labelLength, IDNAInfo &info) const {
1182    int32_t labelEnd=labelLength-1;  // inclusive
1183    int32_t arabicDigits=0;  // -1 for 066x, +1 for 06Fx
1184    for(int32_t i=0; i<=labelEnd; ++i) {
1185        UChar32 c=label[i];
1186        if(c<0xb7) {
1187            // ASCII fastpath
1188        } else if(c<=0x6f9) {
1189            if(c==0xb7) {
1190                // Appendix A.3. MIDDLE DOT (U+00B7)
1191                // Rule Set:
1192                //  False;
1193                //  If Before(cp) .eq.  U+006C And
1194                //     After(cp) .eq.  U+006C Then True;
1195                if(!(0<i && label[i-1]==0x6c &&
1196                     i<labelEnd && label[i+1]==0x6c)) {
1197                    info.labelErrors|=UIDNA_ERROR_CONTEXTO_PUNCTUATION;
1198                }
1199            } else if(c==0x375) {
1200                // Appendix A.4. GREEK LOWER NUMERAL SIGN (KERAIA) (U+0375)
1201                // Rule Set:
1202                //  False;
1203                //  If Script(After(cp)) .eq.  Greek Then True;
1204                UScriptCode script=USCRIPT_INVALID_CODE;
1205                if(i<labelEnd) {
1206                    UErrorCode errorCode=U_ZERO_ERROR;
1207                    int32_t j=i+1;
1208                    U16_NEXT(label, j, labelLength, c);
1209                    script=uscript_getScript(c, &errorCode);
1210                }
1211                if(script!=USCRIPT_GREEK) {
1212                    info.labelErrors|=UIDNA_ERROR_CONTEXTO_PUNCTUATION;
1213                }
1214            } else if(c==0x5f3 || c==0x5f4) {
1215                // Appendix A.5. HEBREW PUNCTUATION GERESH (U+05F3)
1216                // Rule Set:
1217                //  False;
1218                //  If Script(Before(cp)) .eq.  Hebrew Then True;
1219                //
1220                // Appendix A.6. HEBREW PUNCTUATION GERSHAYIM (U+05F4)
1221                // Rule Set:
1222                //  False;
1223                //  If Script(Before(cp)) .eq.  Hebrew Then True;
1224                UScriptCode script=USCRIPT_INVALID_CODE;
1225                if(0<i) {
1226                    UErrorCode errorCode=U_ZERO_ERROR;
1227                    int32_t j=i;
1228                    U16_PREV(label, 0, j, c);
1229                    script=uscript_getScript(c, &errorCode);
1230                }
1231                if(script!=USCRIPT_HEBREW) {
1232                    info.labelErrors|=UIDNA_ERROR_CONTEXTO_PUNCTUATION;
1233                }
1234            } else if(0x660<=c /* && c<=0x6f9 */) {
1235                // Appendix A.8. ARABIC-INDIC DIGITS (0660..0669)
1236                // Rule Set:
1237                //  True;
1238                //  For All Characters:
1239                //    If cp .in. 06F0..06F9 Then False;
1240                //  End For;
1241                //
1242                // Appendix A.9. EXTENDED ARABIC-INDIC DIGITS (06F0..06F9)
1243                // Rule Set:
1244                //  True;
1245                //  For All Characters:
1246                //    If cp .in. 0660..0669 Then False;
1247                //  End For;
1248                if(c<=0x669) {
1249                    if(arabicDigits>0) {
1250                        info.labelErrors|=UIDNA_ERROR_CONTEXTO_DIGITS;
1251                    }
1252                    arabicDigits=-1;
1253                } else if(0x6f0<=c) {
1254                    if(arabicDigits<0) {
1255                        info.labelErrors|=UIDNA_ERROR_CONTEXTO_DIGITS;
1256                    }
1257                    arabicDigits=1;
1258                }
1259            }
1260        } else if(c==0x30fb) {
1261            // Appendix A.7. KATAKANA MIDDLE DOT (U+30FB)
1262            // Rule Set:
1263            //  False;
1264            //  For All Characters:
1265            //    If Script(cp) .in. {Hiragana, Katakana, Han} Then True;
1266            //  End For;
1267            UErrorCode errorCode=U_ZERO_ERROR;
1268            for(int j=0;;) {
1269                if(j>labelEnd) {
1270                    info.labelErrors|=UIDNA_ERROR_CONTEXTO_PUNCTUATION;
1271                    break;
1272                }
1273                U16_NEXT(label, j, labelLength, c);
1274                UScriptCode script=uscript_getScript(c, &errorCode);
1275                if(script==USCRIPT_HIRAGANA || script==USCRIPT_KATAKANA || script==USCRIPT_HAN) {
1276                    break;
1277                }
1278            }
1279        }
1280    }
1281}
1282
1283U_NAMESPACE_END
1284
1285// C API ------------------------------------------------------------------- ***
1286
1287U_NAMESPACE_USE
1288
1289U_CAPI UIDNA * U_EXPORT2
1290uidna_openUTS46(uint32_t options, UErrorCode *pErrorCode) {
1291    return reinterpret_cast<UIDNA *>(IDNA::createUTS46Instance(options, *pErrorCode));
1292}
1293
1294U_CAPI void U_EXPORT2
1295uidna_close(UIDNA *idna) {
1296    delete reinterpret_cast<IDNA *>(idna);
1297}
1298
1299static UBool
1300checkArgs(const void *label, int32_t length,
1301          void *dest, int32_t capacity,
1302          UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1303    if(U_FAILURE(*pErrorCode)) {
1304        return FALSE;
1305    }
1306    // sizeof(UIDNAInfo)=16 in the first API version.
1307    if(pInfo==NULL || pInfo->size<16) {
1308        *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
1309        return FALSE;
1310    }
1311    if( (label==NULL ? length!=0 : length<-1) ||
1312        (dest==NULL ? capacity!=0 : capacity<0) ||
1313        (dest==label && label!=NULL)
1314    ) {
1315        *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
1316        return FALSE;
1317    }
1318    // Set all *pInfo bytes to 0 except for the size field itself.
1319    uprv_memset(&pInfo->size+1, 0, pInfo->size-sizeof(pInfo->size));
1320    return TRUE;
1321}
1322
1323static void
1324idnaInfoToStruct(IDNAInfo &info, UIDNAInfo *pInfo) {
1325    pInfo->isTransitionalDifferent=info.isTransitionalDifferent();
1326    pInfo->errors=info.getErrors();
1327}
1328
1329U_CAPI int32_t U_EXPORT2
1330uidna_labelToASCII(const UIDNA *idna,
1331                   const UChar *label, int32_t length,
1332                   UChar *dest, int32_t capacity,
1333                   UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1334    if(!checkArgs(label, length, dest, capacity, pInfo, pErrorCode)) {
1335        return 0;
1336    }
1337    UnicodeString src((UBool)(length<0), label, length);
1338    UnicodeString destString(dest, 0, capacity);
1339    IDNAInfo info;
1340    reinterpret_cast<const IDNA *>(idna)->labelToASCII(src, destString, info, *pErrorCode);
1341    idnaInfoToStruct(info, pInfo);
1342    return destString.extract(dest, capacity, *pErrorCode);
1343}
1344
1345U_CAPI int32_t U_EXPORT2
1346uidna_labelToUnicode(const UIDNA *idna,
1347                     const UChar *label, int32_t length,
1348                     UChar *dest, int32_t capacity,
1349                     UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1350    if(!checkArgs(label, length, dest, capacity, pInfo, pErrorCode)) {
1351        return 0;
1352    }
1353    UnicodeString src((UBool)(length<0), label, length);
1354    UnicodeString destString(dest, 0, capacity);
1355    IDNAInfo info;
1356    reinterpret_cast<const IDNA *>(idna)->labelToUnicode(src, destString, info, *pErrorCode);
1357    idnaInfoToStruct(info, pInfo);
1358    return destString.extract(dest, capacity, *pErrorCode);
1359}
1360
1361U_CAPI int32_t U_EXPORT2
1362uidna_nameToASCII(const UIDNA *idna,
1363                  const UChar *name, int32_t length,
1364                  UChar *dest, int32_t capacity,
1365                  UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1366    if(!checkArgs(name, length, dest, capacity, pInfo, pErrorCode)) {
1367        return 0;
1368    }
1369    UnicodeString src((UBool)(length<0), name, length);
1370    UnicodeString destString(dest, 0, capacity);
1371    IDNAInfo info;
1372    reinterpret_cast<const IDNA *>(idna)->nameToASCII(src, destString, info, *pErrorCode);
1373    idnaInfoToStruct(info, pInfo);
1374    return destString.extract(dest, capacity, *pErrorCode);
1375}
1376
1377U_CAPI int32_t U_EXPORT2
1378uidna_nameToUnicode(const UIDNA *idna,
1379                    const UChar *name, int32_t length,
1380                    UChar *dest, int32_t capacity,
1381                    UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1382    if(!checkArgs(name, length, dest, capacity, pInfo, pErrorCode)) {
1383        return 0;
1384    }
1385    UnicodeString src((UBool)(length<0), name, length);
1386    UnicodeString destString(dest, 0, capacity);
1387    IDNAInfo info;
1388    reinterpret_cast<const IDNA *>(idna)->nameToUnicode(src, destString, info, *pErrorCode);
1389    idnaInfoToStruct(info, pInfo);
1390    return destString.extract(dest, capacity, *pErrorCode);
1391}
1392
1393U_CAPI int32_t U_EXPORT2
1394uidna_labelToASCII_UTF8(const UIDNA *idna,
1395                        const char *label, int32_t length,
1396                        char *dest, int32_t capacity,
1397                        UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1398    if(!checkArgs(label, length, dest, capacity, pInfo, pErrorCode)) {
1399        return 0;
1400    }
1401    StringPiece src(label, length<0 ? uprv_strlen(label) : length);
1402    CheckedArrayByteSink sink(dest, capacity);
1403    IDNAInfo info;
1404    reinterpret_cast<const IDNA *>(idna)->labelToASCII_UTF8(src, sink, info, *pErrorCode);
1405    idnaInfoToStruct(info, pInfo);
1406    return u_terminateChars(dest, capacity, sink.NumberOfBytesAppended(), pErrorCode);
1407}
1408
1409U_CAPI int32_t U_EXPORT2
1410uidna_labelToUnicodeUTF8(const UIDNA *idna,
1411                         const char *label, int32_t length,
1412                         char *dest, int32_t capacity,
1413                         UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1414    if(!checkArgs(label, length, dest, capacity, pInfo, pErrorCode)) {
1415        return 0;
1416    }
1417    StringPiece src(label, length<0 ? uprv_strlen(label) : length);
1418    CheckedArrayByteSink sink(dest, capacity);
1419    IDNAInfo info;
1420    reinterpret_cast<const IDNA *>(idna)->labelToUnicodeUTF8(src, sink, info, *pErrorCode);
1421    idnaInfoToStruct(info, pInfo);
1422    return u_terminateChars(dest, capacity, sink.NumberOfBytesAppended(), pErrorCode);
1423}
1424
1425U_CAPI int32_t U_EXPORT2
1426uidna_nameToASCII_UTF8(const UIDNA *idna,
1427                       const char *name, int32_t length,
1428                       char *dest, int32_t capacity,
1429                       UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1430    if(!checkArgs(name, length, dest, capacity, pInfo, pErrorCode)) {
1431        return 0;
1432    }
1433    StringPiece src(name, length<0 ? uprv_strlen(name) : length);
1434    CheckedArrayByteSink sink(dest, capacity);
1435    IDNAInfo info;
1436    reinterpret_cast<const IDNA *>(idna)->nameToASCII_UTF8(src, sink, info, *pErrorCode);
1437    idnaInfoToStruct(info, pInfo);
1438    return u_terminateChars(dest, capacity, sink.NumberOfBytesAppended(), pErrorCode);
1439}
1440
1441U_CAPI int32_t U_EXPORT2
1442uidna_nameToUnicodeUTF8(const UIDNA *idna,
1443                        const char *name, int32_t length,
1444                        char *dest, int32_t capacity,
1445                        UIDNAInfo *pInfo, UErrorCode *pErrorCode) {
1446    if(!checkArgs(name, length, dest, capacity, pInfo, pErrorCode)) {
1447        return 0;
1448    }
1449    StringPiece src(name, length<0 ? uprv_strlen(name) : length);
1450    CheckedArrayByteSink sink(dest, capacity);
1451    IDNAInfo info;
1452    reinterpret_cast<const IDNA *>(idna)->nameToUnicodeUTF8(src, sink, info, *pErrorCode);
1453    idnaInfoToStruct(info, pInfo);
1454    return u_terminateChars(dest, capacity, sink.NumberOfBytesAppended(), pErrorCode);
1455}
1456
1457#endif  // UCONFIG_NO_IDNA
1458