icuSources/common/uidna.cpp

   1 /*
   2  *******************************************************************************
   3  *
   4  *   Copyright (C) 2003-2004, International Business Machines
   5  *   Corporation and others.  All Rights Reserved.
   6  *
   7  *******************************************************************************
   8  *   file name:  uidna.cpp
   9  *   encoding:   US-ASCII
  10  *   tab size:   8 (not used)
  11  *   indentation:4
  12  *
  13  *   created on: 2003feb1
  14  *   created by: Ram Viswanadha
  15  */
  16
  17 #include "unicode/utypes.h"
  18
  19 #if !UCONFIG_NO_IDNA
  20
  21 #include "unicode/uidna.h"
  22 #include "unicode/ustring.h"
  23 #include "unicode/usprep.h"
  24 #include "punycode.h"
  25 #include "ustr_imp.h"
  26 #include "cmemory.h"
  27 #include "sprpimpl.h"
  28
  29 /* it is official IDNA ACE Prefix is "xn--" */
  30 static const UChar ACE_PREFIX[] ={ 0x0078,0x006E,0x002d,0x002d } ;
  31 #define ACE_PREFIX_LENGTH 4
  32
  33 #define MAX_LABEL_LENGTH 63
  34 #define HYPHEN      0x002D
  35 /* The Max length of the labels should not be more than 64 */
  36 #define MAX_LABEL_BUFFER_SIZE 100
  37 #define MAX_IDN_BUFFER_SIZE   300
  38
  39 #define CAPITAL_A        0x0041
  40 #define CAPITAL_Z        0x005A
  41 #define LOWER_CASE_DELTA 0x0020
  42 #define FULL_STOP        0x002E
  43 #define DATA_FILE_NAME   "uidna"
  44
  45 inline static UChar
  46 toASCIILower(UChar ch){
  47     if(CAPITAL_A <= ch && ch <= CAPITAL_Z){
  48         return ch + LOWER_CASE_DELTA;
  49     }
  50     return ch;
  51 }
  52
  53 inline static UBool
  54 startsWithPrefix(const UChar* src , int32_t srcLength){
  55     UBool startsWithPrefix = TRUE;
  56
  57     if(srcLength < ACE_PREFIX_LENGTH){
  58         return FALSE;
  59     }
  60
  61     for(int8_t i=0; i< ACE_PREFIX_LENGTH; i++){
  62         if(toASCIILower(src[i]) != ACE_PREFIX[i]){
  63             startsWithPrefix = FALSE;
  64         }
  65     }
  66     return startsWithPrefix;
  67 }
  68
  69 inline static void
  70 toASCIILower(UChar* src, int32_t srcLen){
  71     for(int32_t i=0; i<srcLen; i++){
  72         src[i] = toASCIILower(src[i]);
  73     }
  74 }
  75
  76 inline static int32_t
  77 compareCaseInsensitiveASCII(const UChar* s1, int32_t s1Len,
  78                             const UChar* s2, int32_t s2Len){
  79
  80     int32_t minLength;
  81     int32_t lengthResult;
  82
  83     // are we comparing different lengths?
  84     if(s1Len != s2Len) {
  85         if(s1Len < s2Len) {
  86             minLength = s1Len;
  87             lengthResult = -1;
  88         } else {
  89             minLength = s2Len;
  90             lengthResult = 1;
  91         }
  92     } else {
  93         // ok the lengths are equal
  94         minLength = s1Len;
  95         lengthResult = 0;
  96     }
  97
  98     UChar c1,c2;
  99     int32_t rc;
 100
 101     for(int32_t i =0;/* no condition */;i++) {
 102
 103         /* If we reach the ends of both strings then they match */
 104         if(i == minLength) {
 105             return lengthResult;
 106         }
 107
 108         c1 = s1[i];
 109         c2 = s2[i];
 110
 111         /* Case-insensitive comparison */
 112         if(c1!=c2) {
 113             rc=(int32_t)toASCIILower(c1)-(int32_t)toASCIILower(c2);
 114             if(rc!=0) {
 115                 lengthResult=rc;
 116                 break;
 117             }
 118         }
 119     }
 120     return lengthResult;
 121 }
 122
 123
 124 /**
 125  * Ascertain if the given code point is a label separator as
 126  * defined by the IDNA RFC
 127  *
 128  * @param ch The code point to be ascertained
 129  * @return true if the char is a label separator
 130  * @draft ICU 2.8
 131  */
 132 static inline UBool isLabelSeparator(UChar ch){
 133     switch(ch){
 134         case 0x002e:
 135         case 0x3002:
 136         case 0xFF0E:
 137         case 0xFF61:
 138             return TRUE;
 139         default:
 140             return FALSE;
 141     }
 142 }
 143
 144 // returns the length of the label excluding the separator
 145 // if *limit == separator then the length returned does not include
 146 // the separtor.
 147 static inline int32_t
 148 getNextSeparator(UChar *src,int32_t srcLength,
 149                  UChar **limit,
 150                  UBool *done){
 151     if(srcLength == -1){
 152         int32_t i;
 153         for(i=0 ; ;i++){
 154             if(src[i] == 0){
 155                 *limit = src + i; // point to null
 156                 *done = TRUE;
 157                 return i;
 158             }
 159             if(isLabelSeparator(src[i])){
 160                 *limit = src + (i+1); // go past the delimiter
 161                 return i;
 162
 163             }
 164         }
 165     }else{
 166         int32_t i;
 167         for(i=0;i<srcLength;i++){
 168             if(isLabelSeparator(src[i])){
 169                 *limit = src + (i+1); // go past the delimiter
 170                 return i;
 171             }
 172         }
 173         // we have not found the delimiter
 174         // if(i==srcLength)
 175         *limit = src+srcLength;
 176         *done = TRUE;
 177
 178         return i;
 179     }
 180 }
 181 static inline UBool isLDHChar(UChar ch){
 182     // high runner case
 183     if(ch>0x007A){
 184         return FALSE;
 185     }
 186     //[\\u002D \\u0030-\\u0039 \\u0041-\\u005A \\u0061-\\u007A]
 187     if( (ch==0x002D) ||
 188         (0x0030 <= ch && ch <= 0x0039) ||
 189         (0x0041 <= ch && ch <= 0x005A) ||
 190         (0x0061 <= ch && ch <= 0x007A)
 191       ){
 192         return TRUE;
 193     }
 194     return FALSE;
 195 }
 196
 197 static int32_t
 198 _internal_toASCII(const UChar* src, int32_t srcLength,
 199                   UChar* dest, int32_t destCapacity,
 200                   int32_t options,
 201                   UStringPrepProfile* nameprep,
 202                   UParseError* parseError,
 203                   UErrorCode* status){
 204
 205     UChar b1Stack[MAX_LABEL_BUFFER_SIZE], b2Stack[MAX_LABEL_BUFFER_SIZE];
 206     //initialize pointers to stack buffers
 207     UChar  *b1 = b1Stack, *b2 = b2Stack;
 208     int32_t b1Len, b2Len,
 209             b1Capacity = MAX_LABEL_BUFFER_SIZE,
 210             b2Capacity = MAX_LABEL_BUFFER_SIZE ,
 211             reqLength=0;
 212
 213     int32_t namePrepOptions = ((options & UIDNA_ALLOW_UNASSIGNED) != 0) ? USPREP_ALLOW_UNASSIGNED: 0;
 214     UBool* caseFlags = NULL;
 215
 216     // the source contains all ascii codepoints
 217     UBool srcIsASCII  = TRUE;
 218     // assume the source contains all LDH codepoints
 219     UBool srcIsLDH = TRUE;
 220
 221     int32_t j=0;
 222
 223     //get the options
 224     UBool useSTD3ASCIIRules = (UBool)((options & UIDNA_USE_STD3_RULES) != 0);
 225
 226     int32_t failPos = -1;
 227
 228     // step 2
 229     b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Capacity, namePrepOptions, parseError, status);
 230
 231     if(*status == U_BUFFER_OVERFLOW_ERROR){
 232         // redo processing of string
 233         // we do not have enough room so grow the buffer
 234         b1 = (UChar*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
 235         if(b1==NULL){
 236             *status = U_MEMORY_ALLOCATION_ERROR;
 237             goto CLEANUP;
 238         }
 239
 240         *status = U_ZERO_ERROR; // reset error
 241
 242         b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Len, namePrepOptions, parseError, status);
 243     }
 244     // error bail out
 245     if(U_FAILURE(*status)){
 246         goto CLEANUP;
 247     }
 248
 249     // step 3 & 4
 250     for( j=0;j<b1Len;j++){
 251         if(b1[j] > 0x7F){
 252             srcIsASCII = FALSE;
 253         }else if(isLDHChar(b1[j])==FALSE){  // if the char is in ASCII range verify that it is an LDH character
 254             srcIsLDH = FALSE;
 255             failPos = j;
 256         }
 257     }
 258
 259     if(useSTD3ASCIIRules == TRUE){
 260         // verify 3a and 3b
 261         // 3(a) Verify the absence of non-LDH ASCII code points; that is, the
 262         //  absence of 0..2C, 2E..2F, 3A..40, 5B..60, and 7B..7F.
 263         // 3(b) Verify the absence of leading and trailing hyphen-minus; that
 264         //  is, the absence of U+002D at the beginning and end of the
 265         //  sequence.
 266         if( srcIsLDH == FALSE /* source at this point should not contain anyLDH characters */
 267             || b1[0] ==  HYPHEN || b1[b1Len-1] == HYPHEN){
 268             *status = U_IDNA_STD3_ASCII_RULES_ERROR;
 269
 270             /* populate the parseError struct */
 271             if(srcIsLDH==FALSE){
 272                 // failPos is always set the index of failure
 273                 uprv_syntaxError(b1,failPos, b1Len,parseError);
 274             }else if(b1[0] == HYPHEN){
 275                 // fail position is 0
 276                 uprv_syntaxError(b1,0,b1Len,parseError);
 277             }else{
 278                 // the last index in the source is always length-1
 279                 uprv_syntaxError(b1, (b1Len>0) ? b1Len-1 : b1Len, b1Len,parseError);
 280             }
 281
 282             goto CLEANUP;
 283         }
 284     }
 285     if(srcIsASCII){
 286         if(b1Len <= destCapacity){
 287             uprv_memmove(dest, b1, b1Len * U_SIZEOF_UCHAR);
 288             reqLength = b1Len;
 289         }else{
 290             reqLength = b1Len;
 291             goto CLEANUP;
 292         }
 293     }else{
 294         // step 5 : verify the sequence does not begin with ACE prefix
 295         if(!startsWithPrefix(b1,b1Len)){
 296
 297             //step 6: encode the sequence with punycode
 298
 299             // do not preserve the case flags for now!
 300             // TODO: Preserve the case while implementing the RFE
 301             // caseFlags = (UBool*) uprv_malloc(b1Len * sizeof(UBool));
 302             // uprv_memset(caseFlags,TRUE,b1Len);
 303
 304             b2Len = u_strToPunycode(b1,b1Len,b2,b2Capacity,caseFlags, status);
 305
 306             if(*status == U_BUFFER_OVERFLOW_ERROR){
 307                 // redo processing of string
 308                 /* we do not have enough room so grow the buffer*/
 309                 b2 = (UChar*) uprv_malloc(b2Len * U_SIZEOF_UCHAR);
 310                 if(b2 == NULL){
 311                     *status = U_MEMORY_ALLOCATION_ERROR;
 312                     goto CLEANUP;
 313                 }
 314
 315                 *status = U_ZERO_ERROR; // reset error
 316
 317                 b2Len = u_strToPunycode(b1,b1Len,b2,b2Len,caseFlags, status);
 318             }
 319             //error bail out
 320             if(U_FAILURE(*status)){
 321                 goto CLEANUP;
 322             }
 323             // TODO : Reconsider while implementing the case preserve RFE
 324             // convert all codepoints to lower case ASCII
 325             // toASCIILower(b2,b2Len);
 326             reqLength = b2Len+ACE_PREFIX_LENGTH;
 327
 328             if(reqLength > destCapacity){
 329                 *status = U_BUFFER_OVERFLOW_ERROR;
 330                 goto CLEANUP;
 331             }
 332             //Step 7: prepend the ACE prefix
 333             uprv_memcpy(dest,ACE_PREFIX,ACE_PREFIX_LENGTH * U_SIZEOF_UCHAR);
 334             //Step 6: copy the contents in b2 into dest
 335             uprv_memcpy(dest+ACE_PREFIX_LENGTH, b2, b2Len * U_SIZEOF_UCHAR);
 336
 337         }else{
 338             *status = U_IDNA_ACE_PREFIX_ERROR;
 339             //position of failure is 0
 340             uprv_syntaxError(b1,0,b1Len,parseError);
 341             goto CLEANUP;
 342         }
 343     }
 344
 345     if(reqLength > MAX_LABEL_LENGTH){
 346         *status = U_IDNA_LABEL_TOO_LONG_ERROR;
 347     }
 348
 349 CLEANUP:
 350     if(b1 != b1Stack){
 351         uprv_free(b1);
 352     }
 353     if(b2 != b2Stack){
 354         uprv_free(b2);
 355     }
 356     uprv_free(caseFlags);
 357
 358     return u_terminateUChars(dest, destCapacity, reqLength, status);
 359 }
 360
 361 static int32_t
 362 _internal_toUnicode(const UChar* src, int32_t srcLength,
 363                     UChar* dest, int32_t destCapacity,
 364                     int32_t options,
 365                     UStringPrepProfile* nameprep,
 366                     UParseError* parseError,
 367                     UErrorCode* status){
 368
 369     //get the options
 370     UBool useSTD3ASCIIRules = (UBool)((options & UIDNA_USE_STD3_RULES) != 0);
 371     int32_t namePrepOptions = ((options & UIDNA_ALLOW_UNASSIGNED) != 0) ? USPREP_ALLOW_UNASSIGNED: 0;
 372
 373     UChar b1Stack[MAX_LABEL_BUFFER_SIZE], b2Stack[MAX_LABEL_BUFFER_SIZE], b3Stack[MAX_LABEL_BUFFER_SIZE];
 374
 375     //initialize pointers to stack buffers
 376     UChar  *b1 = b1Stack, *b2 = b2Stack, *b1Prime=NULL, *b3=b3Stack;
 377     int32_t b1Len, b2Len, b1PrimeLen, b3Len,
 378             b1Capacity = MAX_LABEL_BUFFER_SIZE,
 379             b2Capacity = MAX_LABEL_BUFFER_SIZE,
 380             b3Capacity = MAX_LABEL_BUFFER_SIZE,
 381             reqLength=0;
 382
 383     b1Len = 0;
 384     UBool* caseFlags = NULL;
 385
 386     UBool srcIsASCII = TRUE;
 387     UBool srcIsLDH = TRUE;
 388     int32_t failPos =0;
 389
 390     // step 1: find out if all the codepoints in src are ASCII
 391     if(srcLength==-1){
 392         srcLength = 0;
 393         for(;src[srcLength]!=0;){
 394             if(src[srcLength]> 0x7f){
 395                 srcIsASCII = FALSE;
 396             }else if(isLDHChar(src[srcLength])==FALSE){
 397                 // here we do not assemble surrogates
 398                 // since we know that LDH code points
 399                 // are in the ASCII range only
 400                 srcIsLDH = FALSE;
 401                 failPos = srcLength;
 402             }
 403             srcLength++;
 404         }
 405     }else if(srcLength > 0){
 406         for(int32_t j=0; j<srcLength; j++){
 407             if(src[j]> 0x7f){
 408                 srcIsASCII = FALSE;
 409             }else if(isLDHChar(src[j])==FALSE){
 410                 // here we do not assemble surrogates
 411                 // since we know that LDH code points
 412                 // are in the ASCII range only
 413                 srcIsLDH = FALSE;
 414                 failPos = j;
 415             }
 416         }
 417     }else{
 418         return 0;
 419     }
 420
 421     if(srcIsASCII == FALSE){
 422         // step 2: process the string
 423         b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Capacity, namePrepOptions, parseError, status);
 424         if(*status == U_BUFFER_OVERFLOW_ERROR){
 425             // redo processing of string
 426             /* we do not have enough room so grow the buffer*/
 427             b1 = (UChar*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
 428             if(b1==NULL){
 429                 *status = U_MEMORY_ALLOCATION_ERROR;
 430                 goto CLEANUP;
 431             }
 432
 433             *status = U_ZERO_ERROR; // reset error
 434
 435             b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Len, namePrepOptions, parseError, status);
 436         }
 437         //bail out on error
 438         if(U_FAILURE(*status)){
 439             goto CLEANUP;
 440         }
 441     }else{
 442
 443         //just point src to b1
 444         b1 = (UChar*) src;
 445         b1Len = srcLength;
 446     }
 447
 448     //step 3: verify ACE Prefix
 449     if(startsWithPrefix(src,srcLength)){
 450
 451         //step 4: Remove the ACE Prefix
 452         b1Prime = b1 + ACE_PREFIX_LENGTH;
 453         b1PrimeLen  = b1Len - ACE_PREFIX_LENGTH;
 454
 455         //step 5: Decode using punycode
 456         b2Len = u_strFromPunycode(b1Prime, b1PrimeLen, b2, b2Capacity, caseFlags,status);
 457
 458         if(*status == U_BUFFER_OVERFLOW_ERROR){
 459             // redo processing of string
 460             /* we do not have enough room so grow the buffer*/
 461             b2 = (UChar*) uprv_malloc(b2Len * U_SIZEOF_UCHAR);
 462             if(b2==NULL){
 463                 *status = U_MEMORY_ALLOCATION_ERROR;
 464                 goto CLEANUP;
 465             }
 466
 467             *status = U_ZERO_ERROR; // reset error
 468
 469             b2Len =  u_strFromPunycode(b1Prime, b1PrimeLen, b2, b2Len, caseFlags, status);
 470
 471         }
 472
 473
 474         //step 6:Apply toASCII
 475         b3Len = uidna_toASCII(b2, b2Len, b3, b3Capacity,options,parseError, status);
 476
 477         if(*status == U_BUFFER_OVERFLOW_ERROR){
 478             // redo processing of string
 479             /* we do not have enough room so grow the buffer*/
 480             b3 = (UChar*) uprv_malloc(b3Len * U_SIZEOF_UCHAR);
 481             if(b3==NULL){
 482                 *status = U_MEMORY_ALLOCATION_ERROR;
 483                 goto CLEANUP;
 484             }
 485
 486             *status = U_ZERO_ERROR; // reset error
 487
 488             b3Len =  uidna_toASCII(b2,b2Len,b3,b3Len,options,parseError, status);
 489
 490         }
 491         //bail out on error
 492         if(U_FAILURE(*status)){
 493             goto CLEANUP;
 494         }
 495
 496         //step 7: verify
 497         if(compareCaseInsensitiveASCII(b1, b1Len, b3, b3Len) !=0){
 498             *status = U_IDNA_VERIFICATION_ERROR;
 499             goto CLEANUP;
 500         }
 501
 502         //step 8: return output of step 5
 503         reqLength = b2Len;
 504         if(b2Len <= destCapacity) {
 505             uprv_memmove(dest, b2, b2Len * U_SIZEOF_UCHAR);
 506         }
 507     }else{
 508         // verify that STD3 ASCII rules are satisfied
 509         if(useSTD3ASCIIRules == TRUE){
 510             if( srcIsLDH == FALSE /* source contains some non-LDH characters */
 511                 || src[0] ==  HYPHEN || src[srcLength-1] == HYPHEN){
 512                 *status = U_IDNA_STD3_ASCII_RULES_ERROR;
 513
 514                 /* populate the parseError struct */
 515                 if(srcIsLDH==FALSE){
 516                     // failPos is always set the index of failure
 517                     uprv_syntaxError(src,failPos, srcLength,parseError);
 518                 }else if(src[0] == HYPHEN){
 519                     // fail position is 0
 520                     uprv_syntaxError(src,0,srcLength,parseError);
 521                 }else{
 522                     // the last index in the source is always length-1
 523                     uprv_syntaxError(src, (srcLength>0) ? srcLength-1 : srcLength, srcLength,parseError);
 524                 }
 525
 526                 goto CLEANUP;
 527             }
 528         }
 529         //copy the source to destination
 530         if(srcLength <= destCapacity){
 531             uprv_memmove(dest,src,srcLength * U_SIZEOF_UCHAR);
 532         }
 533         reqLength = srcLength;
 534     }
 535
 536 CLEANUP:
 537
 538     if(b1 != b1Stack && b1!=src){
 539         uprv_free(b1);
 540     }
 541     if(b2 != b2Stack){
 542         uprv_free(b2);
 543     }
 544     uprv_free(caseFlags);
 545
 546
 547     // The RFC states that
 548     // <quote>
 549     // ToUnicode never fails. If any step fails, then the original input
 550     // is returned immediately in that step.
 551     // </quote>
 552     // So if any step fails lets copy source to destination
 553     if(U_FAILURE(*status)){
 554         //copy the source to destination
 555         if(dest && srcLength <= destCapacity){
 556           if(srcLength == -1) {
 557             uprv_memmove(dest,src,u_strlen(src)* U_SIZEOF_UCHAR);
 558           } else {
 559             uprv_memmove(dest,src,srcLength * U_SIZEOF_UCHAR);
 560           }
 561         }
 562         reqLength = srcLength;
 563     }
 564
 565     return u_terminateUChars(dest, destCapacity, reqLength, status);
 566 }
 567
 568 U_CAPI int32_t U_EXPORT2
 569 uidna_toASCII(const UChar* src, int32_t srcLength,
 570               UChar* dest, int32_t destCapacity,
 571               int32_t options,
 572               UParseError* parseError,
 573               UErrorCode* status){
 574
 575     if(status == NULL || U_FAILURE(*status)){
 576         return 0;
 577     }
 578     if((src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
 579         *status = U_ILLEGAL_ARGUMENT_ERROR;
 580         return 0;
 581     }
 582
 583     UStringPrepProfile* nameprep = usprep_open(NULL,DATA_FILE_NAME, status);
 584
 585     if(U_FAILURE(*status)){
 586         return -1;
 587     }
 588
 589     int32_t retLen = _internal_toASCII(src, srcLength, dest, destCapacity, options, nameprep, parseError, status);
 590
 591     /* close the profile*/
 592     usprep_close(nameprep);
 593
 594     return retLen;
 595 }
 596
 597 U_CAPI int32_t U_EXPORT2
 598 uidna_toUnicode(const UChar* src, int32_t srcLength,
 599                 UChar* dest, int32_t destCapacity,
 600                 int32_t options,
 601                 UParseError* parseError,
 602                 UErrorCode* status){
 603
 604     if(status == NULL || U_FAILURE(*status)){
 605         return 0;
 606     }
 607     if( (src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
 608         *status = U_ILLEGAL_ARGUMENT_ERROR;
 609         return 0;
 610     }
 611
 612     UStringPrepProfile* nameprep = usprep_open(NULL, DATA_FILE_NAME, status);
 613
 614     if(U_FAILURE(*status)){
 615         return -1;
 616     }
 617
 618     int32_t retLen = _internal_toUnicode(src, srcLength, dest, destCapacity, options, nameprep, parseError, status);
 619
 620     usprep_close(nameprep);
 621
 622     return retLen;
 623 }
 624
 625
 626 U_CAPI int32_t U_EXPORT2
 627 uidna_IDNToASCII(  const UChar *src, int32_t srcLength,
 628                    UChar* dest, int32_t destCapacity,
 629                    int32_t options,
 630                    UParseError *parseError,
 631                    UErrorCode *status){
 632
 633     if(status == NULL || U_FAILURE(*status)){
 634         return 0;
 635     }
 636     if((src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
 637         *status = U_ILLEGAL_ARGUMENT_ERROR;
 638         return 0;
 639     }
 640
 641     int32_t reqLength = 0;
 642
 643     UStringPrepProfile* nameprep = usprep_open(NULL, DATA_FILE_NAME, status);
 644
 645     if(U_FAILURE(*status)){
 646         return 0;
 647     }
 648
 649     //initialize pointers
 650     UChar *delimiter = (UChar*)src;
 651     UChar *labelStart = (UChar*)src;
 652     UChar *currentDest = (UChar*) dest;
 653     int32_t remainingLen = srcLength;
 654     int32_t remainingDestCapacity = destCapacity;
 655     int32_t labelLen = 0, labelReqLength = 0;
 656     UBool done = FALSE;
 657
 658
 659     for(;;){
 660
 661         labelLen = getNextSeparator(labelStart,remainingLen, &delimiter,&done);
 662
 663         labelReqLength = _internal_toASCII( labelStart, labelLen,
 664                                             currentDest, remainingDestCapacity,
 665                                             options, nameprep,
 666                                             parseError, status);
 667
 668         if(*status == U_BUFFER_OVERFLOW_ERROR){
 669
 670             *status = U_ZERO_ERROR; // reset error
 671             remainingDestCapacity = 0;
 672         }
 673
 674
 675         if(U_FAILURE(*status)){
 676             break;
 677         }
 678
 679         reqLength +=labelReqLength;
 680         // adjust the destination pointer
 681         if(labelReqLength < remainingDestCapacity){
 682             currentDest = currentDest + labelReqLength;
 683             remainingDestCapacity -= labelReqLength;
 684         }else{
 685             // should never occur
 686             remainingDestCapacity = 0;
 687         }
 688         if(done == TRUE){
 689             break;
 690         }
 691
 692         // add the label separator
 693         if(remainingDestCapacity > 0){
 694             *currentDest++ = FULL_STOP;
 695             remainingDestCapacity--;
 696         }
 697         reqLength++;
 698
 699         labelStart = delimiter;
 700         if(remainingLen >0 ){
 701             remainingLen = srcLength - (delimiter - src);
 702         }
 703
 704     }
 705
 706     usprep_close(nameprep);
 707
 708     return u_terminateUChars(dest, destCapacity, reqLength, status);
 709 }
 710
 711 U_CAPI int32_t U_EXPORT2
 712 uidna_IDNToUnicode(  const UChar* src, int32_t srcLength,
 713                      UChar* dest, int32_t destCapacity,
 714                      int32_t options,
 715                      UParseError* parseError,
 716                      UErrorCode* status){
 717
 718     if(status == NULL || U_FAILURE(*status)){
 719         return 0;
 720     }
 721     if((src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
 722         *status = U_ILLEGAL_ARGUMENT_ERROR;
 723         return 0;
 724     }
 725
 726     int32_t reqLength = 0;
 727
 728     UStringPrepProfile* nameprep = usprep_open(NULL, DATA_FILE_NAME, status);
 729
 730     if(U_FAILURE(*status)){
 731         return 0;
 732     }
 733
 734     //initialize pointers
 735     UChar *delimiter = (UChar*)src;
 736     UChar *labelStart = (UChar*)src;
 737     UChar *currentDest = (UChar*) dest;
 738     int32_t remainingLen = srcLength;
 739     int32_t remainingDestCapacity = destCapacity;
 740     int32_t labelLen = 0, labelReqLength = 0;
 741     UBool done = FALSE;
 742
 743
 744     for(;;){
 745
 746         labelLen = getNextSeparator(labelStart,remainingLen, &delimiter,&done);
 747
 748         labelReqLength = _internal_toUnicode(labelStart, labelLen,
 749                                              currentDest, remainingDestCapacity,
 750                                              options, nameprep,
 751                                              parseError, status);
 752
 753         if(*status == U_BUFFER_OVERFLOW_ERROR){
 754
 755             *status = U_ZERO_ERROR; // reset error
 756             remainingDestCapacity = 0;
 757         }
 758
 759
 760         if(U_FAILURE(*status)){
 761             break;
 762         }
 763
 764         reqLength +=labelReqLength;
 765         // adjust the destination pointer
 766         if(labelReqLength < remainingDestCapacity){
 767             currentDest = currentDest + labelReqLength;
 768             remainingDestCapacity -= labelReqLength;
 769         }else{
 770             // should never occur
 771             remainingDestCapacity = 0;
 772         }
 773
 774         if(done == TRUE){
 775             break;
 776         }
 777
 778         // add the label separator
 779         if(remainingDestCapacity > 0){
 780             *currentDest++ = FULL_STOP;
 781             remainingDestCapacity--;
 782         }
 783         reqLength++;
 784
 785         labelStart = delimiter;
 786         if(remainingLen >0 ){
 787             remainingLen = srcLength - (delimiter - src);
 788         }
 789
 790     }
 791
 792     usprep_close(nameprep);
 793
 794     return u_terminateUChars(dest, destCapacity, reqLength, status);
 795 }
 796
 797 U_CAPI int32_t U_EXPORT2
 798 uidna_compare(  const UChar *s1, int32_t length1,
 799                 const UChar *s2, int32_t length2,
 800                 int32_t options,
 801                 UErrorCode* status){
 802
 803     if(status == NULL || U_FAILURE(*status)){
 804         return -1;
 805     }
 806
 807     UChar b1Stack[MAX_IDN_BUFFER_SIZE], b2Stack[MAX_IDN_BUFFER_SIZE];
 808     UChar *b1 = b1Stack, *b2 = b2Stack;
 809     int32_t b1Len, b2Len, b1Capacity = MAX_IDN_BUFFER_SIZE, b2Capacity = MAX_IDN_BUFFER_SIZE;
 810     int32_t result=-1;
 811
 812     UParseError parseError;
 813
 814     b1Len = uidna_IDNToASCII(s1, length1, b1, b1Capacity, options, &parseError, status);
 815     if(*status == U_BUFFER_OVERFLOW_ERROR){
 816         // redo processing of string
 817         b1 = (UChar*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
 818         if(b1==NULL){
 819             *status = U_MEMORY_ALLOCATION_ERROR;
 820             goto CLEANUP;
 821         }
 822
 823         *status = U_ZERO_ERROR; // reset error
 824
 825         b1Len = uidna_IDNToASCII(s1,length1,b1,b1Len, options, &parseError, status);
 826
 827     }
 828
 829     b2Len = uidna_IDNToASCII(s2,length2, b2,b2Capacity, options, &parseError, status);
 830     if(*status == U_BUFFER_OVERFLOW_ERROR){
 831         // redo processing of string
 832         b2 = (UChar*) uprv_malloc(b2Len * U_SIZEOF_UCHAR);
 833         if(b2==NULL){
 834             *status = U_MEMORY_ALLOCATION_ERROR;
 835             goto CLEANUP;
 836         }
 837
 838         *status = U_ZERO_ERROR; // reset error
 839
 840         b2Len = uidna_IDNToASCII(s2, length2, b2, b2Len, options, &parseError, status);
 841
 842     }
 843     // when toASCII is applied all label separators are replaced with FULL_STOP
 844     result = compareCaseInsensitiveASCII(b1,b1Len,b2,b2Len);
 845
 846 CLEANUP:
 847     if(b1 != b1Stack){
 848         uprv_free(b1);
 849     }
 850
 851     if(b2 != b2Stack){
 852         uprv_free(b2);
 853     }
 854
 855     return result;
 856 }
 857
 858 #endif /* #if !UCONFIG_NO_IDNA */