summaryrefslogtreecommitdiffstats
path: root/intl/icu/source/common/uidna.cpp
blob: e01c9aea603c6607414802c8165099985569d793 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
// Copyright (C) 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
 *******************************************************************************
 *
 *   Copyright (C) 2003-2014, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 *******************************************************************************
 *   file name:  uidna.cpp
 *   encoding:   US-ASCII
 *   tab size:   8 (not used)
 *   indentation:4
 *
 *   created on: 2003feb1
 *   created by: Ram Viswanadha
 */

#include "unicode/utypes.h"

#if !UCONFIG_NO_IDNA

#include "unicode/uidna.h"
#include "unicode/ustring.h"
#include "unicode/usprep.h"
#include "punycode.h"
#include "ustr_imp.h"
#include "cmemory.h"
#include "uassert.h"
#include "sprpimpl.h"

/* it is official IDNA ACE Prefix is "xn--" */
static const UChar ACE_PREFIX[] ={ 0x0078,0x006E,0x002d,0x002d } ;
#define ACE_PREFIX_LENGTH 4

#define MAX_LABEL_LENGTH 63
/* The Max length of the labels should not be more than MAX_LABEL_LENGTH */
#define MAX_LABEL_BUFFER_SIZE 100

#define MAX_DOMAIN_NAME_LENGTH 255
/* The Max length of the domain names should not be more than MAX_DOMAIN_NAME_LENGTH */
#define MAX_IDN_BUFFER_SIZE   MAX_DOMAIN_NAME_LENGTH+1

#define LOWER_CASE_DELTA 0x0020
#define HYPHEN           0x002D
#define FULL_STOP        0x002E
#define CAPITAL_A        0x0041
#define CAPITAL_Z        0x005A

inline static UChar 
toASCIILower(UChar ch){
    if(CAPITAL_A <= ch && ch <= CAPITAL_Z){
        return ch + LOWER_CASE_DELTA;
    }
    return ch;
}

inline static UBool 
startsWithPrefix(const UChar* src , int32_t srcLength){
    UBool startsWithPrefix = TRUE;

    if(srcLength < ACE_PREFIX_LENGTH){
        return FALSE;
    }

    for(int8_t i=0; i< ACE_PREFIX_LENGTH; i++){
        if(toASCIILower(src[i]) != ACE_PREFIX[i]){
            startsWithPrefix = FALSE;
        }
    }
    return startsWithPrefix;
}


inline static int32_t
compareCaseInsensitiveASCII(const UChar* s1, int32_t s1Len, 
                            const UChar* s2, int32_t s2Len){
    
    int32_t minLength;
    int32_t lengthResult;

    // are we comparing different lengths?
    if(s1Len != s2Len) {
        if(s1Len < s2Len) {
            minLength = s1Len;
            lengthResult = -1;
        } else {
            minLength = s2Len;
            lengthResult = 1;
        }
    } else {
        // ok the lengths are equal
        minLength = s1Len;
        lengthResult = 0;
    }

    UChar c1,c2;
    int32_t rc;

    for(int32_t i =0;/* no condition */;i++) {

        /* If we reach the ends of both strings then they match */
        if(i == minLength) {
            return lengthResult;
        }
        
        c1 = s1[i];
        c2 = s2[i];
        
        /* Case-insensitive comparison */
        if(c1!=c2) {
            rc=(int32_t)toASCIILower(c1)-(int32_t)toASCIILower(c2);
            if(rc!=0) {
                lengthResult=rc;
                break;
            }
        }
    }
    return lengthResult;
}


/**
 * Ascertain if the given code point is a label separator as 
 * defined by the IDNA RFC
 * 
 * @param ch The code point to be ascertained
 * @return true if the char is a label separator
 * @stable ICU 2.8
 */
static inline UBool isLabelSeparator(UChar ch){
    switch(ch){
        case 0x002e:
        case 0x3002:
        case 0xFF0E:
        case 0xFF61:
            return TRUE;
        default:
            return FALSE;           
    }
}

// returns the length of the label excluding the separator
// if *limit == separator then the length returned does not include 
// the separtor.
static inline int32_t
getNextSeparator(UChar *src, int32_t srcLength,
                 UChar **limit, UBool *done){
    if(srcLength == -1){
        int32_t i;
        for(i=0 ; ;i++){
            if(src[i] == 0){
                *limit = src + i; // point to null
                *done = TRUE;
                return i;
            }
            if(isLabelSeparator(src[i])){
                *limit = src + (i+1); // go past the delimiter
                return i;
                
            }
        }
    }else{
        int32_t i;
        for(i=0;i<srcLength;i++){
            if(isLabelSeparator(src[i])){
                *limit = src + (i+1); // go past the delimiter
                return i;
            }
        }
        // we have not found the delimiter
        // if(i==srcLength)
        *limit = src+srcLength;
        *done = TRUE;

        return i;
    }
}
static inline UBool isLDHChar(UChar ch){
    // high runner case
    if(ch>0x007A){
        return FALSE;
    }
    //[\\u002D \\u0030-\\u0039 \\u0041-\\u005A \\u0061-\\u007A]
    if( (ch==0x002D) || 
        (0x0030 <= ch && ch <= 0x0039) ||
        (0x0041 <= ch && ch <= 0x005A) ||
        (0x0061 <= ch && ch <= 0x007A)
      ){
        return TRUE;
    }
    return FALSE;
}

static int32_t 
_internal_toASCII(const UChar* src, int32_t srcLength, 
                  UChar* dest, int32_t destCapacity,
                  int32_t options,
                  UStringPrepProfile* nameprep,
                  UParseError* parseError,
                  UErrorCode* status)
{

    // TODO Revisit buffer handling. The label should not be over 63 ASCII characters. ICU4J may need to be updated too.
    UChar b1Stack[MAX_LABEL_BUFFER_SIZE], b2Stack[MAX_LABEL_BUFFER_SIZE];
    //initialize pointers to stack buffers
    UChar  *b1 = b1Stack, *b2 = b2Stack;
    int32_t b1Len=0, b2Len, 
            b1Capacity = MAX_LABEL_BUFFER_SIZE, 
            b2Capacity = MAX_LABEL_BUFFER_SIZE ,
            reqLength=0;

    int32_t namePrepOptions = ((options & UIDNA_ALLOW_UNASSIGNED) != 0) ? USPREP_ALLOW_UNASSIGNED: 0;
    UBool* caseFlags = NULL;
    
    // the source contains all ascii codepoints
    UBool srcIsASCII  = TRUE;
    // assume the source contains all LDH codepoints
    UBool srcIsLDH = TRUE; 

    int32_t j=0;

    //get the options
    UBool useSTD3ASCIIRules = (UBool)((options & UIDNA_USE_STD3_RULES) != 0);

    int32_t failPos = -1;
    
    if(srcLength == -1){
        srcLength = u_strlen(src);
    }
    
    if(srcLength > b1Capacity){
        b1 = (UChar*) uprv_malloc(srcLength * U_SIZEOF_UCHAR);
        if(b1==NULL){
            *status = U_MEMORY_ALLOCATION_ERROR;
            goto CLEANUP;
        }
        b1Capacity = srcLength;
    }

    // step 1 
    for( j=0;j<srcLength;j++){
        if(src[j] > 0x7F){
            srcIsASCII = FALSE;
        }
        b1[b1Len++] = src[j];
    }
    
    // step 2 is performed only if the source contains non ASCII
    if(srcIsASCII == FALSE){
        
        // step 2    
        b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Capacity, namePrepOptions, parseError, status);

        if(*status == U_BUFFER_OVERFLOW_ERROR){
            // redo processing of string
            // we do not have enough room so grow the buffer
            if(b1 != b1Stack){
                uprv_free(b1);
            }
            b1 = (UChar*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
            if(b1==NULL){
                *status = U_MEMORY_ALLOCATION_ERROR;
                goto CLEANUP;
            }

            *status = U_ZERO_ERROR; // reset error
            
            b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Len, namePrepOptions, parseError, status);
        }
    }
    // error bail out
    if(U_FAILURE(*status)){
        goto CLEANUP;
    }
    if(b1Len == 0){
        *status = U_IDNA_ZERO_LENGTH_LABEL_ERROR;
        goto CLEANUP;
    }

    // for step 3 & 4
    srcIsASCII = TRUE;
    for( j=0;j<b1Len;j++){
        // check if output of usprep_prepare is all ASCII 
        if(b1[j] > 0x7F){
            srcIsASCII = FALSE;
        }else if(isLDHChar(b1[j])==FALSE){  // if the char is in ASCII range verify that it is an LDH character
            srcIsLDH = FALSE;
            failPos = j;
        }
    }
    if(useSTD3ASCIIRules == TRUE){
        // verify 3a and 3b
        // 3(a) Verify the absence of non-LDH ASCII code points; that is, the
        //  absence of 0..2C, 2E..2F, 3A..40, 5B..60, and 7B..7F.
        // 3(b) Verify the absence of leading and trailing hyphen-minus; that
        //  is, the absence of U+002D at the beginning and end of the
        //  sequence.
        if( srcIsLDH == FALSE /* source at this point should not contain anyLDH characters */
            || b1[0] ==  HYPHEN || b1[b1Len-1] == HYPHEN){
            *status = U_IDNA_STD3_ASCII_RULES_ERROR;

            /* populate the parseError struct */
            if(srcIsLDH==FALSE){
                // failPos is always set the index of failure
                uprv_syntaxError(b1,failPos, b1Len,parseError);
            }else if(b1[0] == HYPHEN){
                // fail position is 0 
                uprv_syntaxError(b1,0,b1Len,parseError);
            }else{
                // the last index in the source is always length-1
                uprv_syntaxError(b1, (b1Len>0) ? b1Len-1 : b1Len, b1Len,parseError);
            }

            goto CLEANUP;
        }
    }
    // Step 4: if the source is ASCII then proceed to step 8
    if(srcIsASCII){
        if(b1Len <= destCapacity){
            u_memmove(dest, b1, b1Len);
            reqLength = b1Len;
        }else{
            reqLength = b1Len;
            goto CLEANUP;
        }
    }else{
        // step 5 : verify the sequence does not begin with ACE prefix
        if(!startsWithPrefix(b1,b1Len)){

            //step 6: encode the sequence with punycode

            // do not preserve the case flags for now!
            // TODO: Preserve the case while implementing the RFE
            // caseFlags = (UBool*) uprv_malloc(b1Len * sizeof(UBool));
            // uprv_memset(caseFlags,TRUE,b1Len);

            b2Len = u_strToPunycode(b1,b1Len,b2,b2Capacity,caseFlags, status);

            if(*status == U_BUFFER_OVERFLOW_ERROR){
                // redo processing of string
                /* we do not have enough room so grow the buffer*/
                b2 = (UChar*) uprv_malloc(b2Len * U_SIZEOF_UCHAR); 
                if(b2 == NULL){
                    *status = U_MEMORY_ALLOCATION_ERROR;
                    goto CLEANUP;
                }

                *status = U_ZERO_ERROR; // reset error
                
                b2Len = u_strToPunycode(b1,b1Len,b2,b2Len,caseFlags, status);
            }
            //error bail out
            if(U_FAILURE(*status)){
                goto CLEANUP;
            }
            // TODO : Reconsider while implementing the case preserve RFE
            // convert all codepoints to lower case ASCII
            // toASCIILower(b2,b2Len);
            reqLength = b2Len+ACE_PREFIX_LENGTH;

            if(reqLength > destCapacity){
                *status = U_BUFFER_OVERFLOW_ERROR;
                goto CLEANUP;
            }
            //Step 7: prepend the ACE prefix
            u_memcpy(dest, ACE_PREFIX, ACE_PREFIX_LENGTH);
            //Step 6: copy the contents in b2 into dest
            u_memcpy(dest+ACE_PREFIX_LENGTH, b2, b2Len);

        }else{
            *status = U_IDNA_ACE_PREFIX_ERROR; 
            //position of failure is 0
            uprv_syntaxError(b1,0,b1Len,parseError);
            goto CLEANUP;
        }
    }
    // step 8: verify the length of label
    if(reqLength > MAX_LABEL_LENGTH){
        *status = U_IDNA_LABEL_TOO_LONG_ERROR;
    }

CLEANUP:
    if(b1 != b1Stack){
        uprv_free(b1);
    }
    if(b2 != b2Stack){
        uprv_free(b2);
    }
    uprv_free(caseFlags);
    
    return u_terminateUChars(dest, destCapacity, reqLength, status);
}

static int32_t
_internal_toUnicode(const UChar* src, int32_t srcLength,
                    UChar* dest, int32_t destCapacity,
                    int32_t options,
                    UStringPrepProfile* nameprep,
                    UParseError* parseError,
                    UErrorCode* status)
{

    //get the options
    //UBool useSTD3ASCIIRules = (UBool)((options & UIDNA_USE_STD3_RULES) != 0);
    int32_t namePrepOptions = ((options & UIDNA_ALLOW_UNASSIGNED) != 0) ? USPREP_ALLOW_UNASSIGNED: 0; 

    // TODO Revisit buffer handling. The label should not be over 63 ASCII characters. ICU4J may need to be updated too.
    UChar b1Stack[MAX_LABEL_BUFFER_SIZE], b2Stack[MAX_LABEL_BUFFER_SIZE], b3Stack[MAX_LABEL_BUFFER_SIZE];

    //initialize pointers to stack buffers
    UChar  *b1 = b1Stack, *b2 = b2Stack, *b1Prime=NULL, *b3=b3Stack;
    int32_t b1Len = 0, b2Len, b1PrimeLen, b3Len,
            b1Capacity = MAX_LABEL_BUFFER_SIZE, 
            b2Capacity = MAX_LABEL_BUFFER_SIZE,
            b3Capacity = MAX_LABEL_BUFFER_SIZE,
            reqLength=0;

    UBool* caseFlags = NULL;

    UBool srcIsASCII = TRUE;
    /*UBool srcIsLDH = TRUE;
    int32_t failPos =0;*/

    // step 1: find out if all the codepoints in src are ASCII  
    if(srcLength==-1){
        srcLength = 0;
        for(;src[srcLength]!=0;){
            if(src[srcLength]> 0x7f){
                srcIsASCII = FALSE;
            }/*else if(isLDHChar(src[srcLength])==FALSE){
                // here we do not assemble surrogates
                // since we know that LDH code points
                // are in the ASCII range only
                srcIsLDH = FALSE;
                failPos = srcLength;
            }*/
            srcLength++;
        }
    }else if(srcLength > 0){
        for(int32_t j=0; j<srcLength; j++){
            if(src[j]> 0x7f){
                srcIsASCII = FALSE;
            }/*else if(isLDHChar(src[j])==FALSE){
                // here we do not assemble surrogates
                // since we know that LDH code points
                // are in the ASCII range only
                srcIsLDH = FALSE;
                failPos = j;
            }*/
        }
    }else{
        return 0;
    }
    
    if(srcIsASCII == FALSE){
        // step 2: process the string
        b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Capacity, namePrepOptions, parseError, status);
        if(*status == U_BUFFER_OVERFLOW_ERROR){
            // redo processing of string
            /* we do not have enough room so grow the buffer*/
            b1 = (UChar*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
            if(b1==NULL){
                *status = U_MEMORY_ALLOCATION_ERROR;
                goto CLEANUP;
            }

            *status = U_ZERO_ERROR; // reset error
            
            b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Len, namePrepOptions, parseError, status);
        }
        //bail out on error
        if(U_FAILURE(*status)){
            goto CLEANUP;
        }
    }else{

        //just point src to b1
        b1 = (UChar*) src;
        b1Len = srcLength;
    }

    // The RFC states that 
    // <quote>
    // ToUnicode never fails. If any step fails, then the original input
    // is returned immediately in that step.
    // </quote>

    //step 3: verify ACE Prefix
    if(startsWithPrefix(b1,b1Len)){

        //step 4: Remove the ACE Prefix
        b1Prime = b1 + ACE_PREFIX_LENGTH;
        b1PrimeLen  = b1Len - ACE_PREFIX_LENGTH;

        //step 5: Decode using punycode
        b2Len = u_strFromPunycode(b1Prime, b1PrimeLen, b2, b2Capacity, caseFlags,status);

        if(*status == U_BUFFER_OVERFLOW_ERROR){
            // redo processing of string
            /* we do not have enough room so grow the buffer*/
            b2 = (UChar*) uprv_malloc(b2Len * U_SIZEOF_UCHAR);
            if(b2==NULL){
                *status = U_MEMORY_ALLOCATION_ERROR;
                goto CLEANUP;
            }

            *status = U_ZERO_ERROR; // reset error

            b2Len =  u_strFromPunycode(b1Prime, b1PrimeLen, b2, b2Len, caseFlags, status);
        }


        //step 6:Apply toASCII
        b3Len = uidna_toASCII(b2, b2Len, b3, b3Capacity, options, parseError, status);

        if(*status == U_BUFFER_OVERFLOW_ERROR){
            // redo processing of string
            /* we do not have enough room so grow the buffer*/
            b3 = (UChar*) uprv_malloc(b3Len * U_SIZEOF_UCHAR);
            if(b3==NULL){
                *status = U_MEMORY_ALLOCATION_ERROR;
                goto CLEANUP;
            }

            *status = U_ZERO_ERROR; // reset error

            b3Len =  uidna_toASCII(b2,b2Len,b3,b3Len,options,parseError, status);

        }
        //bail out on error
        if(U_FAILURE(*status)){
            goto CLEANUP;
        }

        //step 7: verify
        if(compareCaseInsensitiveASCII(b1, b1Len, b3, b3Len) !=0){
            // Cause the original to be returned.
            *status = U_IDNA_VERIFICATION_ERROR;
            goto CLEANUP;
        }

        //step 8: return output of step 5
        reqLength = b2Len;
        if(b2Len <= destCapacity) {
            u_memmove(dest, b2, b2Len);
        }
    }
    else{
        // See the start of this if statement for why this is commented out.
        // verify that STD3 ASCII rules are satisfied
        /*if(useSTD3ASCIIRules == TRUE){
            if( srcIsLDH == FALSE // source contains some non-LDH characters
                || src[0] ==  HYPHEN || src[srcLength-1] == HYPHEN){
                *status = U_IDNA_STD3_ASCII_RULES_ERROR;

                // populate the parseError struct
                if(srcIsLDH==FALSE){
                    // failPos is always set the index of failure
                    uprv_syntaxError(src,failPos, srcLength,parseError);
                }else if(src[0] == HYPHEN){
                    // fail position is 0 
                    uprv_syntaxError(src,0,srcLength,parseError);
                }else{
                    // the last index in the source is always length-1
                    uprv_syntaxError(src, (srcLength>0) ? srcLength-1 : srcLength, srcLength,parseError);
                }

                goto CLEANUP;
            }
        }*/
        // just return the source
        //copy the source to destination
        if(srcLength <= destCapacity){
            u_memmove(dest, src, srcLength);
        }
        reqLength = srcLength;
    }


CLEANUP:

    if(b1 != b1Stack && b1!=src){
        uprv_free(b1);
    }
    if(b2 != b2Stack){
        uprv_free(b2);
    }
    uprv_free(caseFlags);

    // The RFC states that 
    // <quote>
    // ToUnicode never fails. If any step fails, then the original input
    // is returned immediately in that step.
    // </quote>
    // So if any step fails lets copy source to destination
    if(U_FAILURE(*status)){
        //copy the source to destination
        if(dest && srcLength <= destCapacity){
            // srcLength should have already been set earlier.
            U_ASSERT(srcLength >= 0);
            u_memmove(dest, src, srcLength);
        }
        reqLength = srcLength;
        *status = U_ZERO_ERROR;
    }

    return u_terminateUChars(dest, destCapacity, reqLength, status);
}

U_CAPI int32_t U_EXPORT2
uidna_toASCII(const UChar* src, int32_t srcLength, 
              UChar* dest, int32_t destCapacity,
              int32_t options,
              UParseError* parseError,
              UErrorCode* status){
    
    if(status == NULL || U_FAILURE(*status)){
        return 0;
    }
    if((src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
        *status = U_ILLEGAL_ARGUMENT_ERROR;
        return 0;
    }

    UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
    
    if(U_FAILURE(*status)){
        return -1;
    }
    
    int32_t retLen = _internal_toASCII(src, srcLength, dest, destCapacity, options, nameprep, parseError, status);
    
    /* close the profile*/
    usprep_close(nameprep);
    
    return retLen;
}

U_CAPI int32_t U_EXPORT2
uidna_toUnicode(const UChar* src, int32_t srcLength,
                UChar* dest, int32_t destCapacity,
                int32_t options,
                UParseError* parseError,
                UErrorCode* status){

    if(status == NULL || U_FAILURE(*status)){
        return 0;
    }
    if( (src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
        *status = U_ILLEGAL_ARGUMENT_ERROR;
        return 0;
    }  

    UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
    
    if(U_FAILURE(*status)){
        return -1;
    }
    
    int32_t retLen = _internal_toUnicode(src, srcLength, dest, destCapacity, options, nameprep, parseError, status);

    usprep_close(nameprep);
    
    return retLen;
}


U_CAPI int32_t U_EXPORT2
uidna_IDNToASCII(  const UChar *src, int32_t srcLength,
                   UChar* dest, int32_t destCapacity,
                   int32_t options,
                   UParseError *parseError,
                   UErrorCode *status){

    if(status == NULL || U_FAILURE(*status)){
        return 0;
    }
    if((src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
        *status = U_ILLEGAL_ARGUMENT_ERROR;
        return 0;
    }

    int32_t reqLength = 0;

    UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
    
    if(U_FAILURE(*status)){
        return 0;
    }

    //initialize pointers 
    UChar *delimiter = (UChar*)src;
    UChar *labelStart = (UChar*)src;
    UChar *currentDest = (UChar*) dest;
    int32_t remainingLen = srcLength;
    int32_t remainingDestCapacity = destCapacity;
    int32_t labelLen = 0, labelReqLength = 0;
    UBool done = FALSE;


    for(;;){

        labelLen = getNextSeparator(labelStart,remainingLen, &delimiter,&done);
        labelReqLength = 0;
        if(!(labelLen==0 && done)){// make sure this is not a root label separator.
        
            labelReqLength = _internal_toASCII( labelStart, labelLen, 
                                                currentDest, remainingDestCapacity, 
                                                options, nameprep, 
                                                parseError, status);
    
            if(*status == U_BUFFER_OVERFLOW_ERROR){
                
                *status = U_ZERO_ERROR; // reset error
                remainingDestCapacity = 0;
            }
        }

    
        if(U_FAILURE(*status)){
            break;
        }
        
        reqLength +=labelReqLength;
        // adjust the destination pointer
        if(labelReqLength < remainingDestCapacity){
            currentDest = currentDest + labelReqLength;
            remainingDestCapacity -= labelReqLength;
        }else{
            // should never occur
            remainingDestCapacity = 0;
        }

        if(done == TRUE){
            break;
        }

        // add the label separator
        if(remainingDestCapacity > 0){
            *currentDest++ = FULL_STOP;
            remainingDestCapacity--;
        }
        reqLength++;

        labelStart = delimiter;
        if(remainingLen >0 ){
            remainingLen = (int32_t)(srcLength - (delimiter - src));
        }

    }

    if(reqLength > MAX_DOMAIN_NAME_LENGTH){
        *status = U_IDNA_DOMAIN_NAME_TOO_LONG_ERROR;
    }

    usprep_close(nameprep);
    
    return u_terminateUChars(dest, destCapacity, reqLength, status);
}

U_CAPI int32_t U_EXPORT2
uidna_IDNToUnicode(  const UChar* src, int32_t srcLength,
                     UChar* dest, int32_t destCapacity,
                     int32_t options,
                     UParseError* parseError,
                     UErrorCode* status){
    
    if(status == NULL || U_FAILURE(*status)){
        return 0;
    }
    if((src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
        *status = U_ILLEGAL_ARGUMENT_ERROR;
        return 0;
    }

    int32_t reqLength = 0;

    UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
    
    if(U_FAILURE(*status)){
        return 0;
    }

    //initialize pointers
    UChar *delimiter = (UChar*)src;
    UChar *labelStart = (UChar*)src;
    UChar *currentDest = (UChar*) dest;
    int32_t remainingLen = srcLength;
    int32_t remainingDestCapacity = destCapacity;
    int32_t labelLen = 0, labelReqLength = 0;
    UBool done = FALSE;

    for(;;){

        labelLen = getNextSeparator(labelStart,remainingLen, &delimiter,&done);
        
        // The RFC states that 
        // <quote>
        // ToUnicode never fails. If any step fails, then the original input
        // is returned immediately in that step.
        // </quote>
        // _internal_toUnicode will copy the label.
        /*if(labelLen==0 && done==FALSE){ 
            *status = U_IDNA_ZERO_LENGTH_LABEL_ERROR;
            break;
        }*/
        
        labelReqLength = _internal_toUnicode(labelStart, labelLen, 
                                             currentDest, remainingDestCapacity, 
                                             options, nameprep, 
                                             parseError, status);

        if(*status == U_BUFFER_OVERFLOW_ERROR){
            *status = U_ZERO_ERROR; // reset error
            remainingDestCapacity = 0;
        }

        if(U_FAILURE(*status)){
            break;
        }
        
        reqLength +=labelReqLength;
        // adjust the destination pointer
        if(labelReqLength < remainingDestCapacity){
            currentDest = currentDest + labelReqLength;
            remainingDestCapacity -= labelReqLength;
        }else{
            // should never occur
            remainingDestCapacity = 0;
        }

        if(done == TRUE){
            break;
        }

        // add the label separator
        // Unlike the ToASCII operation we don't normalize the label separators
        if(remainingDestCapacity > 0){
            *currentDest++ = *(labelStart + labelLen);
            remainingDestCapacity--;
        }
        reqLength++;

        labelStart = delimiter;
        if(remainingLen >0 ){
            remainingLen = (int32_t)(srcLength - (delimiter - src));
        }

    }

    if(reqLength > MAX_DOMAIN_NAME_LENGTH){
        *status = U_IDNA_DOMAIN_NAME_TOO_LONG_ERROR;
    }

    usprep_close(nameprep);
    
    return u_terminateUChars(dest, destCapacity, reqLength, status);
}

U_CAPI int32_t U_EXPORT2
uidna_compare(  const UChar *s1, int32_t length1,
                const UChar *s2, int32_t length2,
                int32_t options,
                UErrorCode* status){

    if(status == NULL || U_FAILURE(*status)){
        return -1;
    }

    UChar b1Stack[MAX_IDN_BUFFER_SIZE], b2Stack[MAX_IDN_BUFFER_SIZE];
    UChar *b1 = b1Stack, *b2 = b2Stack;
    int32_t b1Len, b2Len, b1Capacity = MAX_IDN_BUFFER_SIZE, b2Capacity = MAX_IDN_BUFFER_SIZE;
    int32_t result=-1;
    
    UParseError parseError;

    b1Len = uidna_IDNToASCII(s1, length1, b1, b1Capacity, options, &parseError, status);
    if(*status == U_BUFFER_OVERFLOW_ERROR){
        // redo processing of string
        b1 = (UChar*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
        if(b1==NULL){
            *status = U_MEMORY_ALLOCATION_ERROR;
            goto CLEANUP;
        }

        *status = U_ZERO_ERROR; // reset error
        
        b1Len = uidna_IDNToASCII(s1,length1,b1,b1Len, options, &parseError, status);
        
    }

    b2Len = uidna_IDNToASCII(s2,length2, b2,b2Capacity, options, &parseError, status);
    if(*status == U_BUFFER_OVERFLOW_ERROR){
        // redo processing of string
        b2 = (UChar*) uprv_malloc(b2Len * U_SIZEOF_UCHAR);
        if(b2==NULL){
            *status = U_MEMORY_ALLOCATION_ERROR;
            goto CLEANUP;
        }

        *status = U_ZERO_ERROR; // reset error
        
        b2Len = uidna_IDNToASCII(s2, length2, b2, b2Len, options, &parseError, status);
        
    }
    // when toASCII is applied all label separators are replaced with FULL_STOP
    result = compareCaseInsensitiveASCII(b1,b1Len,b2,b2Len);

CLEANUP:
    if(b1 != b1Stack){
        uprv_free(b1);
    }

    if(b2 != b2Stack){
        uprv_free(b2);
    }

    return result;
}

#endif /* #if !UCONFIG_NO_IDNA */