icuSources/common/uidna.cpp

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4  *******************************************************************************
   5  *
   6  *   Copyright (C) 2003-2014, International Business Machines
   7  *   Corporation and others.  All Rights Reserved.
   8  *
   9  *******************************************************************************
  10  *   file name:  uidna.cpp
  11  *   encoding:   UTF-8
  12  *   tab size:   8 (not used)
  13  *   indentation:4
  14  *
  15  *   created on: 2003feb1
  16  *   created by: Ram Viswanadha
  17  */
  18
  19 #include "unicode/utypes.h"
  20
  21 #if !UCONFIG_NO_IDNA
  22
  23 #include "unicode/uidna.h"
  24 #include "unicode/ustring.h"
  25 #include "unicode/usprep.h"
  26 #include "punycode.h"
  27 #include "ustr_imp.h"
  28 #include "cmemory.h"
  29 #include "uassert.h"
  30 #include "sprpimpl.h"
  31
  32 /* it is official IDNA ACE Prefix is "xn--" */
  33 static const UChar ACE_PREFIX[] ={ 0x0078,0x006E,0x002d,0x002d } ;
  34 #define ACE_PREFIX_LENGTH 4
  35
  36 #define MAX_LABEL_LENGTH 63
  37 /* The Max length of the labels should not be more than MAX_LABEL_LENGTH */
  38 #define MAX_LABEL_BUFFER_SIZE 100
  39
  40 #define MAX_DOMAIN_NAME_LENGTH 255
  41 /* The Max length of the domain names should not be more than MAX_DOMAIN_NAME_LENGTH */
  42 #define MAX_IDN_BUFFER_SIZE   MAX_DOMAIN_NAME_LENGTH+1
  43
  44 #define LOWER_CASE_DELTA 0x0020
  45 #define HYPHEN           0x002D
  46 #define FULL_STOP        0x002E
  47 #define CAPITAL_A        0x0041
  48 #define CAPITAL_Z        0x005A
  49
  50 inline static UChar
  51 toASCIILower(UChar ch){
  52     if(CAPITAL_A <= ch && ch <= CAPITAL_Z){
  53         return ch + LOWER_CASE_DELTA;
  54     }
  55     return ch;
  56 }
  57
  58 inline static UBool
  59 startsWithPrefix(const UChar* src , int32_t srcLength){
  60     UBool startsWithPrefix = TRUE;
  61
  62     if(srcLength < ACE_PREFIX_LENGTH){
  63         return FALSE;
  64     }
  65
  66     for(int8_t i=0; i< ACE_PREFIX_LENGTH; i++){
  67         if(toASCIILower(src[i]) != ACE_PREFIX[i]){
  68             startsWithPrefix = FALSE;
  69         }
  70     }
  71     return startsWithPrefix;
  72 }
  73
  74
  75 inline static int32_t
  76 compareCaseInsensitiveASCII(const UChar* s1, int32_t s1Len,
  77                             const UChar* s2, int32_t s2Len){
  78
  79     int32_t minLength;
  80     int32_t lengthResult;
  81
  82     // are we comparing different lengths?
  83     if(s1Len != s2Len) {
  84         if(s1Len < s2Len) {
  85             minLength = s1Len;
  86             lengthResult = -1;
  87         } else {
  88             minLength = s2Len;
  89             lengthResult = 1;
  90         }
  91     } else {
  92         // ok the lengths are equal
  93         minLength = s1Len;
  94         lengthResult = 0;
  95     }
  96
  97     UChar c1,c2;
  98     int32_t rc;
  99
 100     for(int32_t i =0;/* no condition */;i++) {
 101
 102         /* If we reach the ends of both strings then they match */
 103         if(i == minLength) {
 104             return lengthResult;
 105         }
 106
 107         c1 = s1[i];
 108         c2 = s2[i];
 109
 110         /* Case-insensitive comparison */
 111         if(c1!=c2) {
 112             rc=(int32_t)toASCIILower(c1)-(int32_t)toASCIILower(c2);
 113             if(rc!=0) {
 114                 lengthResult=rc;
 115                 break;
 116             }
 117         }
 118     }
 119     return lengthResult;
 120 }
 121
 122
 123 /**
 124  * Ascertain if the given code point is a label separator as
 125  * defined by the IDNA RFC
 126  *
 127  * @param ch The code point to be ascertained
 128  * @return true if the char is a label separator
 129  * @stable ICU 2.8
 130  */
 131 static inline UBool isLabelSeparator(UChar ch){
 132     switch(ch){
 133         case 0x002e:
 134         case 0x3002:
 135         case 0xFF0E:
 136         case 0xFF61:
 137             return TRUE;
 138         default:
 139             return FALSE;
 140     }
 141 }
 142
 143 // returns the length of the label excluding the separator
 144 // if *limit == separator then the length returned does not include
 145 // the separtor.
 146 static inline int32_t
 147 getNextSeparator(UChar *src, int32_t srcLength,
 148                  UChar **limit, UBool *done){
 149     if(srcLength == -1){
 150         int32_t i;
 151         for(i=0 ; ;i++){
 152             if(src[i] == 0){
 153                 *limit = src + i; // point to null
 154                 *done = TRUE;
 155                 return i;
 156             }
 157             if(isLabelSeparator(src[i])){
 158                 *limit = src + (i+1); // go past the delimiter
 159                 return i;
 160
 161             }
 162         }
 163     }else{
 164         int32_t i;
 165         for(i=0;i<srcLength;i++){
 166             if(isLabelSeparator(src[i])){
 167                 *limit = src + (i+1); // go past the delimiter
 168                 return i;
 169             }
 170         }
 171         // we have not found the delimiter
 172         // if(i==srcLength)
 173         *limit = src+srcLength;
 174         *done = TRUE;
 175
 176         return i;
 177     }
 178 }
 179 static inline UBool isLDHChar(UChar ch){
 180     // high runner case
 181     if(ch>0x007A){
 182         return FALSE;
 183     }
 184     //[\\u002D \\u0030-\\u0039 \\u0041-\\u005A \\u0061-\\u007A]
 185     if( (ch==0x002D) ||
 186         (0x0030 <= ch && ch <= 0x0039) ||
 187         (0x0041 <= ch && ch <= 0x005A) ||
 188         (0x0061 <= ch && ch <= 0x007A)
 189       ){
 190         return TRUE;
 191     }
 192     return FALSE;
 193 }
 194
 195 static int32_t
 196 _internal_toASCII(const UChar* src, int32_t srcLength,
 197                   UChar* dest, int32_t destCapacity,
 198                   int32_t options,
 199                   UStringPrepProfile* nameprep,
 200                   UParseError* parseError,
 201                   UErrorCode* status)
 202 {
 203
 204     // TODO Revisit buffer handling. The label should not be over 63 ASCII characters. ICU4J may need to be updated too.
 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=0, 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     if(srcLength == -1){
 229         srcLength = u_strlen(src);
 230     }
 231
 232     if(srcLength > b1Capacity){
 233         b1 = (UChar*) uprv_malloc(srcLength * U_SIZEOF_UCHAR);
 234         if(b1==NULL){
 235             *status = U_MEMORY_ALLOCATION_ERROR;
 236             goto CLEANUP;
 237         }
 238         b1Capacity = srcLength;
 239     }
 240
 241     // step 1
 242     for( j=0;j<srcLength;j++){
 243         if(src[j] > 0x7F){
 244             srcIsASCII = FALSE;
 245         }
 246         b1[b1Len++] = src[j];
 247     }
 248
 249     // step 2 is performed only if the source contains non ASCII
 250     if(srcIsASCII == FALSE){
 251
 252         // step 2
 253         b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Capacity, namePrepOptions, parseError, status);
 254
 255         if(*status == U_BUFFER_OVERFLOW_ERROR){
 256             // redo processing of string
 257             // we do not have enough room so grow the buffer
 258             if(b1 != b1Stack){
 259                 uprv_free(b1);
 260             }
 261             b1 = (UChar*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
 262             if(b1==NULL){
 263                 *status = U_MEMORY_ALLOCATION_ERROR;
 264                 goto CLEANUP;
 265             }
 266
 267             *status = U_ZERO_ERROR; // reset error
 268
 269             b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Len, namePrepOptions, parseError, status);
 270         }
 271     }
 272     // error bail out
 273     if(U_FAILURE(*status)){
 274         goto CLEANUP;
 275     }
 276     if(b1Len == 0){
 277         *status = U_IDNA_ZERO_LENGTH_LABEL_ERROR;
 278         goto CLEANUP;
 279     }
 280
 281     // for step 3 & 4
 282     srcIsASCII = TRUE;
 283     for( j=0;j<b1Len;j++){
 284         // check if output of usprep_prepare is all ASCII
 285         if(b1[j] > 0x7F){
 286             srcIsASCII = FALSE;
 287         }else if(isLDHChar(b1[j])==FALSE){  // if the char is in ASCII range verify that it is an LDH character
 288             srcIsLDH = FALSE;
 289             failPos = j;
 290         }
 291     }
 292     if(useSTD3ASCIIRules == TRUE){
 293         // verify 3a and 3b
 294         // 3(a) Verify the absence of non-LDH ASCII code points; that is, the
 295         //  absence of 0..2C, 2E..2F, 3A..40, 5B..60, and 7B..7F.
 296         // 3(b) Verify the absence of leading and trailing hyphen-minus; that
 297         //  is, the absence of U+002D at the beginning and end of the
 298         //  sequence.
 299         if( srcIsLDH == FALSE /* source at this point should not contain anyLDH characters */
 300             || b1[0] ==  HYPHEN || b1[b1Len-1] == HYPHEN){
 301             *status = U_IDNA_STD3_ASCII_RULES_ERROR;
 302
 303             /* populate the parseError struct */
 304             if(srcIsLDH==FALSE){
 305                 // failPos is always set the index of failure
 306                 uprv_syntaxError(b1,failPos, b1Len,parseError);
 307             }else if(b1[0] == HYPHEN){
 308                 // fail position is 0
 309                 uprv_syntaxError(b1,0,b1Len,parseError);
 310             }else{
 311                 // the last index in the source is always length-1
 312                 uprv_syntaxError(b1, (b1Len>0) ? b1Len-1 : b1Len, b1Len,parseError);
 313             }
 314
 315             goto CLEANUP;
 316         }
 317     }
 318     // Step 4: if the source is ASCII then proceed to step 8
 319     if(srcIsASCII){
 320         if(b1Len <= destCapacity){
 321             u_memmove(dest, b1, b1Len);
 322             reqLength = b1Len;
 323         }else{
 324             reqLength = b1Len;
 325             goto CLEANUP;
 326         }
 327     }else{
 328         // step 5 : verify the sequence does not begin with ACE prefix
 329         if(!startsWithPrefix(b1,b1Len)){
 330
 331             //step 6: encode the sequence with punycode
 332
 333             // do not preserve the case flags for now!
 334             // TODO: Preserve the case while implementing the RFE
 335             // caseFlags = (UBool*) uprv_malloc(b1Len * sizeof(UBool));
 336             // uprv_memset(caseFlags,TRUE,b1Len);
 337
 338             b2Len = u_strToPunycode(b1,b1Len,b2,b2Capacity,caseFlags, status);
 339
 340             if(*status == U_BUFFER_OVERFLOW_ERROR){
 341                 // redo processing of string
 342                 /* we do not have enough room so grow the buffer*/
 343                 b2 = (UChar*) uprv_malloc(b2Len * U_SIZEOF_UCHAR);
 344                 if(b2 == NULL){
 345                     *status = U_MEMORY_ALLOCATION_ERROR;
 346                     goto CLEANUP;
 347                 }
 348
 349                 *status = U_ZERO_ERROR; // reset error
 350
 351                 b2Len = u_strToPunycode(b1,b1Len,b2,b2Len,caseFlags, status);
 352             }
 353             //error bail out
 354             if(U_FAILURE(*status)){
 355                 goto CLEANUP;
 356             }
 357             // TODO : Reconsider while implementing the case preserve RFE
 358             // convert all codepoints to lower case ASCII
 359             // toASCIILower(b2,b2Len);
 360             reqLength = b2Len+ACE_PREFIX_LENGTH;
 361
 362             if(reqLength > destCapacity){
 363                 *status = U_BUFFER_OVERFLOW_ERROR;
 364                 goto CLEANUP;
 365             }
 366             //Step 7: prepend the ACE prefix
 367             u_memcpy(dest, ACE_PREFIX, ACE_PREFIX_LENGTH);
 368             //Step 6: copy the contents in b2 into dest
 369             u_memcpy(dest+ACE_PREFIX_LENGTH, b2, b2Len);
 370
 371         }else{
 372             *status = U_IDNA_ACE_PREFIX_ERROR;
 373             //position of failure is 0
 374             uprv_syntaxError(b1,0,b1Len,parseError);
 375             goto CLEANUP;
 376         }
 377     }
 378     // step 8: verify the length of label
 379     if(reqLength > MAX_LABEL_LENGTH){
 380         *status = U_IDNA_LABEL_TOO_LONG_ERROR;
 381     }
 382
 383 CLEANUP:
 384     if(b1 != b1Stack){
 385         uprv_free(b1);
 386     }
 387     if(b2 != b2Stack){
 388         uprv_free(b2);
 389     }
 390     uprv_free(caseFlags);
 391
 392     return u_terminateUChars(dest, destCapacity, reqLength, status);
 393 }
 394
 395 static int32_t
 396 _internal_toUnicode(const UChar* src, int32_t srcLength,
 397                     UChar* dest, int32_t destCapacity,
 398                     int32_t options,
 399                     UStringPrepProfile* nameprep,
 400                     UParseError* parseError,
 401                     UErrorCode* status)
 402 {
 403
 404     //get the options
 405     //UBool useSTD3ASCIIRules = (UBool)((options & UIDNA_USE_STD3_RULES) != 0);
 406     int32_t namePrepOptions = ((options & UIDNA_ALLOW_UNASSIGNED) != 0) ? USPREP_ALLOW_UNASSIGNED: 0;
 407
 408     // TODO Revisit buffer handling. The label should not be over 63 ASCII characters. ICU4J may need to be updated too.
 409     UChar b1Stack[MAX_LABEL_BUFFER_SIZE], b2Stack[MAX_LABEL_BUFFER_SIZE], b3Stack[MAX_LABEL_BUFFER_SIZE];
 410
 411     //initialize pointers to stack buffers
 412     UChar  *b1 = b1Stack, *b2 = b2Stack, *b1Prime=NULL, *b3=b3Stack;
 413     int32_t b1Len = 0, b2Len, b1PrimeLen, b3Len,
 414             b1Capacity = MAX_LABEL_BUFFER_SIZE,
 415             b2Capacity = MAX_LABEL_BUFFER_SIZE,
 416             b3Capacity = MAX_LABEL_BUFFER_SIZE,
 417             reqLength=0;
 418
 419     UBool* caseFlags = NULL;
 420
 421     UBool srcIsASCII = TRUE;
 422     /*UBool srcIsLDH = TRUE;
 423     int32_t failPos =0;*/
 424
 425     // step 1: find out if all the codepoints in src are ASCII
 426     if(srcLength==-1){
 427         srcLength = 0;
 428         for(;src[srcLength]!=0;){
 429             if(src[srcLength]> 0x7f){
 430                 srcIsASCII = FALSE;
 431             }/*else if(isLDHChar(src[srcLength])==FALSE){
 432                 // here we do not assemble surrogates
 433                 // since we know that LDH code points
 434                 // are in the ASCII range only
 435                 srcIsLDH = FALSE;
 436                 failPos = srcLength;
 437             }*/
 438             srcLength++;
 439         }
 440     }else if(srcLength > 0){
 441         for(int32_t j=0; j<srcLength; j++){
 442             if(src[j]> 0x7f){
 443                 srcIsASCII = FALSE;
 444             }/*else if(isLDHChar(src[j])==FALSE){
 445                 // here we do not assemble surrogates
 446                 // since we know that LDH code points
 447                 // are in the ASCII range only
 448                 srcIsLDH = FALSE;
 449                 failPos = j;
 450             }*/
 451         }
 452     }else{
 453         return 0;
 454     }
 455
 456     if(srcIsASCII == FALSE){
 457         // step 2: process the string
 458         b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Capacity, namePrepOptions, parseError, status);
 459         if(*status == U_BUFFER_OVERFLOW_ERROR){
 460             // redo processing of string
 461             /* we do not have enough room so grow the buffer*/
 462             b1 = (UChar*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
 463             if(b1==NULL){
 464                 *status = U_MEMORY_ALLOCATION_ERROR;
 465                 goto CLEANUP;
 466             }
 467
 468             *status = U_ZERO_ERROR; // reset error
 469
 470             b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Len, namePrepOptions, parseError, status);
 471         }
 472         //bail out on error
 473         if(U_FAILURE(*status)){
 474             goto CLEANUP;
 475         }
 476     }else{
 477
 478         //just point src to b1
 479         b1 = (UChar*) src;
 480         b1Len = srcLength;
 481     }
 482
 483     // The RFC states that
 484     // <quote>
 485     // ToUnicode never fails. If any step fails, then the original input
 486     // is returned immediately in that step.
 487     // </quote>
 488
 489     //step 3: verify ACE Prefix
 490     if(startsWithPrefix(b1,b1Len)){
 491
 492         //step 4: Remove the ACE Prefix
 493         b1Prime = b1 + ACE_PREFIX_LENGTH;
 494         b1PrimeLen  = b1Len - ACE_PREFIX_LENGTH;
 495
 496         //step 5: Decode using punycode
 497         b2Len = u_strFromPunycode(b1Prime, b1PrimeLen, b2, b2Capacity, caseFlags,status);
 498
 499         if(*status == U_BUFFER_OVERFLOW_ERROR){
 500             // redo processing of string
 501             /* we do not have enough room so grow the buffer*/
 502             b2 = (UChar*) uprv_malloc(b2Len * U_SIZEOF_UCHAR);
 503             if(b2==NULL){
 504                 *status = U_MEMORY_ALLOCATION_ERROR;
 505                 goto CLEANUP;
 506             }
 507
 508             *status = U_ZERO_ERROR; // reset error
 509
 510             b2Len =  u_strFromPunycode(b1Prime, b1PrimeLen, b2, b2Len, caseFlags, status);
 511         }
 512
 513
 514         //step 6:Apply toASCII
 515         b3Len = uidna_toASCII(b2, b2Len, b3, b3Capacity, options, parseError, status);
 516
 517         if(*status == U_BUFFER_OVERFLOW_ERROR){
 518             // redo processing of string
 519             /* we do not have enough room so grow the buffer*/
 520             b3 = (UChar*) uprv_malloc(b3Len * U_SIZEOF_UCHAR);
 521             if(b3==NULL){
 522                 *status = U_MEMORY_ALLOCATION_ERROR;
 523                 goto CLEANUP;
 524             }
 525
 526             *status = U_ZERO_ERROR; // reset error
 527
 528             b3Len =  uidna_toASCII(b2,b2Len,b3,b3Len,options,parseError, status);
 529
 530         }
 531         //bail out on error
 532         if(U_FAILURE(*status)){
 533             goto CLEANUP;
 534         }
 535
 536         //step 7: verify
 537         if(compareCaseInsensitiveASCII(b1, b1Len, b3, b3Len) !=0){
 538             // Cause the original to be returned.
 539             *status = U_IDNA_VERIFICATION_ERROR;
 540             goto CLEANUP;
 541         }
 542
 543         //step 8: return output of step 5
 544         reqLength = b2Len;
 545         if(b2Len <= destCapacity) {
 546             u_memmove(dest, b2, b2Len);
 547         }
 548     }
 549     else{
 550         // See the start of this if statement for why this is commented out.
 551         // verify that STD3 ASCII rules are satisfied
 552         /*if(useSTD3ASCIIRules == TRUE){
 553             if( srcIsLDH == FALSE // source contains some non-LDH characters
 554                 || src[0] ==  HYPHEN || src[srcLength-1] == HYPHEN){
 555                 *status = U_IDNA_STD3_ASCII_RULES_ERROR;
 556
 557                 // populate the parseError struct
 558                 if(srcIsLDH==FALSE){
 559                     // failPos is always set the index of failure
 560                     uprv_syntaxError(src,failPos, srcLength,parseError);
 561                 }else if(src[0] == HYPHEN){
 562                     // fail position is 0
 563                     uprv_syntaxError(src,0,srcLength,parseError);
 564                 }else{
 565                     // the last index in the source is always length-1
 566                     uprv_syntaxError(src, (srcLength>0) ? srcLength-1 : srcLength, srcLength,parseError);
 567                 }
 568
 569                 goto CLEANUP;
 570             }
 571         }*/
 572         // just return the source
 573         //copy the source to destination
 574         if(srcLength <= destCapacity){
 575             u_memmove(dest, src, srcLength);
 576         }
 577         reqLength = srcLength;
 578     }
 579
 580
 581 CLEANUP:
 582
 583     if(b1 != b1Stack && b1!=src){
 584         uprv_free(b1);
 585     }
 586     if(b2 != b2Stack){
 587         uprv_free(b2);
 588     }
 589     uprv_free(caseFlags);
 590
 591     // The RFC states that
 592     // <quote>
 593     // ToUnicode never fails. If any step fails, then the original input
 594     // is returned immediately in that step.
 595     // </quote>
 596     // So if any step fails lets copy source to destination
 597     if(U_FAILURE(*status)){
 598         //copy the source to destination
 599         if(dest && srcLength <= destCapacity){
 600             // srcLength should have already been set earlier.
 601             U_ASSERT(srcLength >= 0);
 602             u_memmove(dest, src, srcLength);
 603         }
 604         reqLength = srcLength;
 605         *status = U_ZERO_ERROR;
 606     }
 607
 608     return u_terminateUChars(dest, destCapacity, reqLength, status);
 609 }
 610
 611 U_CAPI int32_t U_EXPORT2
 612 uidna_toASCII(const UChar* src, int32_t srcLength,
 613               UChar* dest, int32_t destCapacity,
 614               int32_t options,
 615               UParseError* parseError,
 616               UErrorCode* status){
 617
 618     if(status == NULL || U_FAILURE(*status)){
 619         return 0;
 620     }
 621     if((src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
 622         *status = U_ILLEGAL_ARGUMENT_ERROR;
 623         return 0;
 624     }
 625
 626     UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
 627
 628     if(U_FAILURE(*status)){
 629         return -1;
 630     }
 631
 632     int32_t retLen = _internal_toASCII(src, srcLength, dest, destCapacity, options, nameprep, parseError, status);
 633
 634     /* close the profile*/
 635     usprep_close(nameprep);
 636
 637     return retLen;
 638 }
 639
 640 U_CAPI int32_t U_EXPORT2
 641 uidna_toUnicode(const UChar* src, int32_t srcLength,
 642                 UChar* dest, int32_t destCapacity,
 643                 int32_t options,
 644                 UParseError* parseError,
 645                 UErrorCode* status){
 646
 647     if(status == NULL || U_FAILURE(*status)){
 648         return 0;
 649     }
 650     if( (src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
 651         *status = U_ILLEGAL_ARGUMENT_ERROR;
 652         return 0;
 653     }
 654
 655     UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
 656
 657     if(U_FAILURE(*status)){
 658         return -1;
 659     }
 660
 661     int32_t retLen = _internal_toUnicode(src, srcLength, dest, destCapacity, options, nameprep, parseError, status);
 662
 663     usprep_close(nameprep);
 664
 665     return retLen;
 666 }
 667
 668
 669 U_CAPI int32_t U_EXPORT2
 670 uidna_IDNToASCII(  const UChar *src, int32_t srcLength,
 671                    UChar* dest, int32_t destCapacity,
 672                    int32_t options,
 673                    UParseError *parseError,
 674                    UErrorCode *status){
 675
 676     if(status == NULL || U_FAILURE(*status)){
 677         return 0;
 678     }
 679     if((src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
 680         *status = U_ILLEGAL_ARGUMENT_ERROR;
 681         return 0;
 682     }
 683
 684     int32_t reqLength = 0;
 685
 686     UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
 687
 688     if(U_FAILURE(*status)){
 689         return 0;
 690     }
 691
 692     //initialize pointers
 693     UChar *delimiter = (UChar*)src;
 694     UChar *labelStart = (UChar*)src;
 695     UChar *currentDest = (UChar*) dest;
 696     int32_t remainingLen = srcLength;
 697     int32_t remainingDestCapacity = destCapacity;
 698     int32_t labelLen = 0, labelReqLength = 0;
 699     UBool done = FALSE;
 700
 701
 702     for(;;){
 703
 704         labelLen = getNextSeparator(labelStart,remainingLen, &delimiter,&done);
 705         labelReqLength = 0;
 706         if(!(labelLen==0 && done)){// make sure this is not a root label separator.
 707
 708             labelReqLength = _internal_toASCII( labelStart, labelLen,
 709                                                 currentDest, remainingDestCapacity,
 710                                                 options, nameprep,
 711                                                 parseError, status);
 712
 713             if(*status == U_BUFFER_OVERFLOW_ERROR){
 714
 715                 *status = U_ZERO_ERROR; // reset error
 716                 remainingDestCapacity = 0;
 717             }
 718         }
 719
 720
 721         if(U_FAILURE(*status)){
 722             break;
 723         }
 724
 725         reqLength +=labelReqLength;
 726         // adjust the destination pointer
 727         if(labelReqLength < remainingDestCapacity){
 728             currentDest = currentDest + labelReqLength;
 729             remainingDestCapacity -= labelReqLength;
 730         }else{
 731             // should never occur
 732             remainingDestCapacity = 0;
 733         }
 734
 735         if(done == TRUE){
 736             break;
 737         }
 738
 739         // add the label separator
 740         if(remainingDestCapacity > 0){
 741             *currentDest++ = FULL_STOP;
 742             remainingDestCapacity--;
 743         }
 744         reqLength++;
 745
 746         labelStart = delimiter;
 747         if(remainingLen >0 ){
 748             remainingLen = (int32_t)(srcLength - (delimiter - src));
 749         }
 750
 751     }
 752
 753     if(reqLength > MAX_DOMAIN_NAME_LENGTH){
 754         *status = U_IDNA_DOMAIN_NAME_TOO_LONG_ERROR;
 755     }
 756
 757     usprep_close(nameprep);
 758
 759     return u_terminateUChars(dest, destCapacity, reqLength, status);
 760 }
 761
 762 U_CAPI int32_t U_EXPORT2
 763 uidna_IDNToUnicode(  const UChar* src, int32_t srcLength,
 764                      UChar* dest, int32_t destCapacity,
 765                      int32_t options,
 766                      UParseError* parseError,
 767                      UErrorCode* status){
 768
 769     if(status == NULL || U_FAILURE(*status)){
 770         return 0;
 771     }
 772     if((src==NULL) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
 773         *status = U_ILLEGAL_ARGUMENT_ERROR;
 774         return 0;
 775     }
 776
 777     int32_t reqLength = 0;
 778
 779     UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
 780
 781     if(U_FAILURE(*status)){
 782         return 0;
 783     }
 784
 785     //initialize pointers
 786     UChar *delimiter = (UChar*)src;
 787     UChar *labelStart = (UChar*)src;
 788     UChar *currentDest = (UChar*) dest;
 789     int32_t remainingLen = srcLength;
 790     int32_t remainingDestCapacity = destCapacity;
 791     int32_t labelLen = 0, labelReqLength = 0;
 792     UBool done = FALSE;
 793
 794     for(;;){
 795
 796         labelLen = getNextSeparator(labelStart,remainingLen, &delimiter,&done);
 797
 798         // The RFC states that
 799         // <quote>
 800         // ToUnicode never fails. If any step fails, then the original input
 801         // is returned immediately in that step.
 802         // </quote>
 803         // _internal_toUnicode will copy the label.
 804         /*if(labelLen==0 && done==FALSE){
 805             *status = U_IDNA_ZERO_LENGTH_LABEL_ERROR;
 806             break;
 807         }*/
 808
 809         labelReqLength = _internal_toUnicode(labelStart, labelLen,
 810                                              currentDest, remainingDestCapacity,
 811                                              options, nameprep,
 812                                              parseError, status);
 813
 814         if(*status == U_BUFFER_OVERFLOW_ERROR){
 815             *status = U_ZERO_ERROR; // reset error
 816             remainingDestCapacity = 0;
 817         }
 818
 819         if(U_FAILURE(*status)){
 820             break;
 821         }
 822
 823         reqLength +=labelReqLength;
 824         // adjust the destination pointer
 825         if(labelReqLength < remainingDestCapacity){
 826             currentDest = currentDest + labelReqLength;
 827             remainingDestCapacity -= labelReqLength;
 828         }else{
 829             // should never occur
 830             remainingDestCapacity = 0;
 831         }
 832
 833         if(done == TRUE){
 834             break;
 835         }
 836
 837         // add the label separator
 838         // Unlike the ToASCII operation we don't normalize the label separators
 839         if(remainingDestCapacity > 0){
 840             *currentDest++ = *(labelStart + labelLen);
 841             remainingDestCapacity--;
 842         }
 843         reqLength++;
 844
 845         labelStart = delimiter;
 846         if(remainingLen >0 ){
 847             remainingLen = (int32_t)(srcLength - (delimiter - src));
 848         }
 849
 850     }
 851
 852     if(reqLength > MAX_DOMAIN_NAME_LENGTH){
 853         *status = U_IDNA_DOMAIN_NAME_TOO_LONG_ERROR;
 854     }
 855
 856     usprep_close(nameprep);
 857
 858     return u_terminateUChars(dest, destCapacity, reqLength, status);
 859 }
 860
 861 U_CAPI int32_t U_EXPORT2
 862 uidna_compare(  const UChar *s1, int32_t length1,
 863                 const UChar *s2, int32_t length2,
 864                 int32_t options,
 865                 UErrorCode* status){
 866
 867     if(status == NULL || U_FAILURE(*status)){
 868         return -1;
 869     }
 870
 871     UChar b1Stack[MAX_IDN_BUFFER_SIZE], b2Stack[MAX_IDN_BUFFER_SIZE];
 872     UChar *b1 = b1Stack, *b2 = b2Stack;
 873     int32_t b1Len, b2Len, b1Capacity = MAX_IDN_BUFFER_SIZE, b2Capacity = MAX_IDN_BUFFER_SIZE;
 874     int32_t result=-1;
 875
 876     UParseError parseError;
 877
 878     b1Len = uidna_IDNToASCII(s1, length1, b1, b1Capacity, options, &parseError, status);
 879     if(*status == U_BUFFER_OVERFLOW_ERROR){
 880         // redo processing of string
 881         b1 = (UChar*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
 882         if(b1==NULL){
 883             *status = U_MEMORY_ALLOCATION_ERROR;
 884             goto CLEANUP;
 885         }
 886
 887         *status = U_ZERO_ERROR; // reset error
 888
 889         b1Len = uidna_IDNToASCII(s1,length1,b1,b1Len, options, &parseError, status);
 890
 891     }
 892
 893     b2Len = uidna_IDNToASCII(s2,length2, b2,b2Capacity, options, &parseError, status);
 894     if(*status == U_BUFFER_OVERFLOW_ERROR){
 895         // redo processing of string
 896         b2 = (UChar*) uprv_malloc(b2Len * U_SIZEOF_UCHAR);
 897         if(b2==NULL){
 898             *status = U_MEMORY_ALLOCATION_ERROR;
 899             goto CLEANUP;
 900         }
 901
 902         *status = U_ZERO_ERROR; // reset error
 903
 904         b2Len = uidna_IDNToASCII(s2, length2, b2, b2Len, options, &parseError, status);
 905
 906     }
 907     // when toASCII is applied all label separators are replaced with FULL_STOP
 908     result = compareCaseInsensitiveASCII(b1,b1Len,b2,b2Len);
 909
 910 CLEANUP:
 911     if(b1 != b1Stack){
 912         uprv_free(b1);
 913     }
 914
 915     if(b2 != b2Stack){
 916         uprv_free(b2);
 917     }
 918
 919     return result;
 920 }
 921
 922 #endif /* #if !UCONFIG_NO_IDNA */