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uidna.cpp (28986B)


      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 char16_t 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 char16_t
     51 toASCIILower(char16_t 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 char16_t* src , int32_t srcLength){
     60    if(srcLength < ACE_PREFIX_LENGTH){
     61        return false;
     62    }
     63 
     64    for(int8_t i=0; i< ACE_PREFIX_LENGTH; i++){
     65        if(toASCIILower(src[i]) != ACE_PREFIX[i]){
     66            return false;
     67        }
     68    }
     69    return true;
     70 }
     71 
     72 
     73 inline static int32_t
     74 compareCaseInsensitiveASCII(const char16_t* s1, int32_t s1Len,
     75                            const char16_t* s2, int32_t s2Len){
     76    
     77    int32_t minLength;
     78    int32_t lengthResult;
     79 
     80    // are we comparing different lengths?
     81    if(s1Len != s2Len) {
     82        if(s1Len < s2Len) {
     83            minLength = s1Len;
     84            lengthResult = -1;
     85        } else {
     86            minLength = s2Len;
     87            lengthResult = 1;
     88        }
     89    } else {
     90        // ok the lengths are equal
     91        minLength = s1Len;
     92        lengthResult = 0;
     93    }
     94 
     95    char16_t c1,c2;
     96    int32_t rc;
     97 
     98    for(int32_t i =0;/* no condition */;i++) {
     99 
    100        /* If we reach the ends of both strings then they match */
    101        if(i == minLength) {
    102            return lengthResult;
    103        }
    104        
    105        c1 = s1[i];
    106        c2 = s2[i];
    107        
    108        /* Case-insensitive comparison */
    109        if(c1!=c2) {
    110            rc = static_cast<int32_t>(toASCIILower(c1)) - static_cast<int32_t>(toASCIILower(c2));
    111            if(rc!=0) {
    112                lengthResult=rc;
    113                break;
    114            }
    115        }
    116    }
    117    return lengthResult;
    118 }
    119 
    120 
    121 /**
    122 * Ascertain if the given code point is a label separator as 
    123 * defined by the IDNA RFC
    124 * 
    125 * @param ch The code point to be ascertained
    126 * @return true if the char is a label separator
    127 * @stable ICU 2.8
    128 */
    129 static inline UBool isLabelSeparator(char16_t ch){
    130    switch(ch){
    131        case 0x002e:
    132        case 0x3002:
    133        case 0xFF0E:
    134        case 0xFF61:
    135            return true;
    136        default:
    137            return false;           
    138    }
    139 }
    140 
    141 // returns the length of the label excluding the separator
    142 // if *limit == separator then the length returned does not include 
    143 // the separtor.
    144 static inline int32_t
    145 getNextSeparator(char16_t *src, int32_t srcLength,
    146                 char16_t **limit, UBool *done){
    147    if(srcLength == -1){
    148        int32_t i;
    149        for(i=0 ; ;i++){
    150            if(src[i] == 0){
    151                *limit = src + i; // point to null
    152                *done = true;
    153                return i;
    154            }
    155            if(isLabelSeparator(src[i])){
    156                *limit = src + (i+1); // go past the delimiter
    157                return i;
    158                
    159            }
    160        }
    161    }else{
    162        int32_t i;
    163        for(i=0;i<srcLength;i++){
    164            if(isLabelSeparator(src[i])){
    165                *limit = src + (i+1); // go past the delimiter
    166                return i;
    167            }
    168        }
    169        // we have not found the delimiter
    170        // if(i==srcLength)
    171        *limit = src+srcLength;
    172        *done = true;
    173 
    174        return i;
    175    }
    176 }
    177 static inline UBool isLDHChar(char16_t ch){
    178    // high runner case
    179    if(ch>0x007A){
    180        return false;
    181    }
    182    //[\\u002D \\u0030-\\u0039 \\u0041-\\u005A \\u0061-\\u007A]
    183    if( (ch==0x002D) || 
    184        (0x0030 <= ch && ch <= 0x0039) ||
    185        (0x0041 <= ch && ch <= 0x005A) ||
    186        (0x0061 <= ch && ch <= 0x007A)
    187      ){
    188        return true;
    189    }
    190    return false;
    191 }
    192 
    193 static int32_t 
    194 _internal_toASCII(const char16_t* src, int32_t srcLength,
    195                  char16_t* dest, int32_t destCapacity,
    196                  int32_t options,
    197                  UStringPrepProfile* nameprep,
    198                  UParseError* parseError,
    199                  UErrorCode* status)
    200 {
    201 
    202    // TODO Revisit buffer handling. The label should not be over 63 ASCII characters. ICU4J may need to be updated too.
    203    char16_t b1Stack[MAX_LABEL_BUFFER_SIZE], b2Stack[MAX_LABEL_BUFFER_SIZE];
    204    //initialize pointers to stack buffers
    205    char16_t  *b1 = b1Stack, *b2 = b2Stack;
    206    int32_t b1Len=0, b2Len, 
    207            b1Capacity = MAX_LABEL_BUFFER_SIZE, 
    208            b2Capacity = MAX_LABEL_BUFFER_SIZE ,
    209            reqLength=0;
    210 
    211    int32_t namePrepOptions = ((options & UIDNA_ALLOW_UNASSIGNED) != 0) ? USPREP_ALLOW_UNASSIGNED: 0;
    212    UBool* caseFlags = nullptr;
    213    
    214    // the source contains all ascii codepoints
    215    UBool srcIsASCII  = true;
    216    // assume the source contains all LDH codepoints
    217    UBool srcIsLDH = true; 
    218 
    219    int32_t j=0;
    220 
    221    //get the options
    222    UBool useSTD3ASCIIRules = static_cast<UBool>((options & UIDNA_USE_STD3_RULES) != 0);
    223 
    224    int32_t failPos = -1;
    225    
    226    if(srcLength == -1){
    227        srcLength = u_strlen(src);
    228    }
    229    
    230    if(srcLength > b1Capacity){
    231        b1 = static_cast<char16_t*>(uprv_malloc(srcLength * U_SIZEOF_UCHAR));
    232        if(b1==nullptr){
    233            *status = U_MEMORY_ALLOCATION_ERROR;
    234            goto CLEANUP;
    235        }
    236        b1Capacity = srcLength;
    237    }
    238 
    239    // step 1 
    240    for( j=0;j<srcLength;j++){
    241        if(src[j] > 0x7F){
    242            srcIsASCII = false;
    243        }
    244        b1[b1Len++] = src[j];
    245    }
    246    
    247    // step 2 is performed only if the source contains non ASCII
    248    if(srcIsASCII == false){
    249        
    250        // step 2    
    251        UErrorCode bufferStatus = U_ZERO_ERROR;
    252        b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Capacity, namePrepOptions, parseError, &bufferStatus);
    253 
    254        if(bufferStatus == U_BUFFER_OVERFLOW_ERROR){
    255            // redo processing of string
    256            // we do not have enough room so grow the buffer
    257            if(b1 != b1Stack){
    258                uprv_free(b1);
    259            }
    260            b1 = static_cast<char16_t*>(uprv_malloc(b1Len * U_SIZEOF_UCHAR));
    261            if(b1==nullptr){
    262                *status = U_MEMORY_ALLOCATION_ERROR;
    263                goto CLEANUP;
    264            }
    265 
    266            bufferStatus = U_ZERO_ERROR; // reset error
    267 
    268            b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Len, namePrepOptions, parseError, &bufferStatus);
    269        }
    270        if (U_FAILURE(bufferStatus)) {
    271            *status = bufferStatus;
    272        }
    273    }
    274    // error bail out
    275    if(U_FAILURE(*status)){
    276        goto CLEANUP;
    277    }
    278    if(b1Len == 0){
    279        *status = U_IDNA_ZERO_LENGTH_LABEL_ERROR;
    280        goto CLEANUP;
    281    }
    282 
    283    // for step 3 & 4
    284    srcIsASCII = true;
    285    for( j=0;j<b1Len;j++){
    286        // check if output of usprep_prepare is all ASCII 
    287        if(b1[j] > 0x7F){
    288            srcIsASCII = false;
    289        }else if(isLDHChar(b1[j])==false){  // if the char is in ASCII range verify that it is an LDH character
    290            srcIsLDH = false;
    291            failPos = j;
    292        }
    293    }
    294    if(useSTD3ASCIIRules){
    295        // verify 3a and 3b
    296        // 3(a) Verify the absence of non-LDH ASCII code points; that is, the
    297        //  absence of 0..2C, 2E..2F, 3A..40, 5B..60, and 7B..7F.
    298        // 3(b) Verify the absence of leading and trailing hyphen-minus; that
    299        //  is, the absence of U+002D at the beginning and end of the
    300        //  sequence.
    301        if( srcIsLDH == false /* source at this point should not contain anyLDH characters */
    302            || b1[0] ==  HYPHEN || b1[b1Len-1] == HYPHEN){
    303            *status = U_IDNA_STD3_ASCII_RULES_ERROR;
    304 
    305            /* populate the parseError struct */
    306            if(srcIsLDH==false){
    307                // failPos is always set the index of failure
    308                uprv_syntaxError(b1,failPos, b1Len,parseError);
    309            }else if(b1[0] == HYPHEN){
    310                // fail position is 0 
    311                uprv_syntaxError(b1,0,b1Len,parseError);
    312            }else{
    313                // the last index in the source is always length-1
    314                uprv_syntaxError(b1, (b1Len>0) ? b1Len-1 : b1Len, b1Len,parseError);
    315            }
    316 
    317            goto CLEANUP;
    318        }
    319    }
    320    // Step 4: if the source is ASCII then proceed to step 8
    321    if(srcIsASCII){
    322        if(b1Len <= destCapacity){
    323            u_memmove(dest, b1, b1Len);
    324            reqLength = b1Len;
    325        }else{
    326            reqLength = b1Len;
    327            goto CLEANUP;
    328        }
    329    }else{
    330        // step 5 : verify the sequence does not begin with ACE prefix
    331        if(!startsWithPrefix(b1,b1Len)){
    332 
    333            //step 6: encode the sequence with punycode
    334 
    335            // do not preserve the case flags for now!
    336            // TODO: Preserve the case while implementing the RFE
    337            // caseFlags = (UBool*) uprv_malloc(b1Len * sizeof(UBool));
    338            // uprv_memset(caseFlags,true,b1Len);
    339 
    340            UErrorCode bufferStatus = U_ZERO_ERROR;
    341            b2Len = u_strToPunycode(b1,b1Len,b2,b2Capacity,caseFlags,&bufferStatus);
    342 
    343            if(bufferStatus == U_BUFFER_OVERFLOW_ERROR){
    344                // redo processing of string
    345                /* we do not have enough room so grow the buffer*/
    346                b2 = static_cast<char16_t*>(uprv_malloc(b2Len * U_SIZEOF_UCHAR));
    347                if(b2 == nullptr){
    348                    *status = U_MEMORY_ALLOCATION_ERROR;
    349                    goto CLEANUP;
    350                }
    351 
    352                bufferStatus = U_ZERO_ERROR; // reset error
    353 
    354                b2Len = u_strToPunycode(b1,b1Len,b2,b2Len,caseFlags,&bufferStatus);
    355            }
    356            //error bail out
    357            if(U_FAILURE(bufferStatus)){
    358                *status = bufferStatus;
    359                goto CLEANUP;
    360            }
    361            // TODO : Reconsider while implementing the case preserve RFE
    362            // convert all codepoints to lower case ASCII
    363            // toASCIILower(b2,b2Len);
    364            reqLength = b2Len+ACE_PREFIX_LENGTH;
    365 
    366            if(reqLength > destCapacity){
    367                *status = U_BUFFER_OVERFLOW_ERROR;
    368                goto CLEANUP;
    369            }
    370            //Step 7: prepend the ACE prefix
    371            u_memcpy(dest, ACE_PREFIX, ACE_PREFIX_LENGTH);
    372            //Step 6: copy the contents in b2 into dest
    373            u_memcpy(dest+ACE_PREFIX_LENGTH, b2, b2Len);
    374 
    375        }else{
    376            *status = U_IDNA_ACE_PREFIX_ERROR; 
    377            //position of failure is 0
    378            uprv_syntaxError(b1,0,b1Len,parseError);
    379            goto CLEANUP;
    380        }
    381    }
    382    // step 8: verify the length of label
    383    if(reqLength > MAX_LABEL_LENGTH){
    384        *status = U_IDNA_LABEL_TOO_LONG_ERROR;
    385    }
    386 
    387 CLEANUP:
    388    if(b1 != b1Stack){
    389        uprv_free(b1);
    390    }
    391    if(b2 != b2Stack){
    392        uprv_free(b2);
    393    }
    394    uprv_free(caseFlags);
    395    
    396    return u_terminateUChars(dest, destCapacity, reqLength, status);
    397 }
    398 
    399 static int32_t
    400 _internal_toUnicode(const char16_t* src, int32_t srcLength,
    401                    char16_t* dest, int32_t destCapacity,
    402                    int32_t options,
    403                    UStringPrepProfile* nameprep,
    404                    UParseError* parseError,
    405                    UErrorCode* status)
    406 {
    407 
    408    //get the options
    409    //UBool useSTD3ASCIIRules = (UBool)((options & UIDNA_USE_STD3_RULES) != 0);
    410    int32_t namePrepOptions = ((options & UIDNA_ALLOW_UNASSIGNED) != 0) ? USPREP_ALLOW_UNASSIGNED: 0; 
    411 
    412    // TODO Revisit buffer handling. The label should not be over 63 ASCII characters. ICU4J may need to be updated too.
    413    char16_t b1Stack[MAX_LABEL_BUFFER_SIZE], b2Stack[MAX_LABEL_BUFFER_SIZE], b3Stack[MAX_LABEL_BUFFER_SIZE];
    414 
    415    //initialize pointers to stack buffers
    416    char16_t  *b1 = b1Stack, *b2 = b2Stack, *b1Prime=nullptr, *b3=b3Stack;
    417    int32_t b1Len = 0, b2Len, b1PrimeLen, b3Len,
    418            b1Capacity = MAX_LABEL_BUFFER_SIZE, 
    419            b2Capacity = MAX_LABEL_BUFFER_SIZE,
    420            b3Capacity = MAX_LABEL_BUFFER_SIZE,
    421            reqLength=0;
    422 
    423    UBool* caseFlags = nullptr;
    424 
    425    UBool srcIsASCII = true;
    426    /*UBool srcIsLDH = true;
    427    int32_t failPos =0;*/
    428 
    429    // step 1: find out if all the codepoints in src are ASCII  
    430    if(srcLength==-1){
    431        srcLength = 0;
    432        for(;src[srcLength]!=0;){
    433            if(src[srcLength]> 0x7f){
    434                srcIsASCII = false;
    435            }/*else if(isLDHChar(src[srcLength])==false){
    436                // here we do not assemble surrogates
    437                // since we know that LDH code points
    438                // are in the ASCII range only
    439                srcIsLDH = false;
    440                failPos = srcLength;
    441            }*/
    442            srcLength++;
    443        }
    444    }else if(srcLength > 0){
    445        for(int32_t j=0; j<srcLength; j++){
    446            if(src[j]> 0x7f){
    447                srcIsASCII = false;
    448                break;
    449            }/*else if(isLDHChar(src[j])==false){
    450                // here we do not assemble surrogates
    451                // since we know that LDH code points
    452                // are in the ASCII range only
    453                srcIsLDH = false;
    454                failPos = j;
    455            }*/
    456        }
    457    }else{
    458        return 0;
    459    }
    460    
    461    if(srcIsASCII == false){
    462        // step 2: process the string
    463        UErrorCode bufferStatus = U_ZERO_ERROR;
    464        b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Capacity, namePrepOptions, parseError, &bufferStatus);
    465        if(bufferStatus == U_BUFFER_OVERFLOW_ERROR){
    466            // redo processing of string
    467            /* we do not have enough room so grow the buffer*/
    468            b1 = static_cast<char16_t*>(uprv_malloc(b1Len * U_SIZEOF_UCHAR));
    469            if(b1==nullptr){
    470                *status = U_MEMORY_ALLOCATION_ERROR;
    471                goto CLEANUP;
    472            }
    473 
    474            bufferStatus = U_ZERO_ERROR; // reset error
    475 
    476            b1Len = usprep_prepare(nameprep, src, srcLength, b1, b1Len, namePrepOptions, parseError, &bufferStatus);
    477        }
    478        //bail out on error
    479        if(U_FAILURE(bufferStatus)){
    480            *status = bufferStatus;
    481            goto CLEANUP;
    482        }
    483    }else{
    484 
    485        //just point src to b1
    486        b1 = const_cast<char16_t*>(src);
    487        b1Len = srcLength;
    488    }
    489 
    490    // The RFC states that 
    491    // <quote>
    492    // ToUnicode never fails. If any step fails, then the original input
    493    // is returned immediately in that step.
    494    // </quote>
    495 
    496    //step 3: verify ACE Prefix
    497    if(startsWithPrefix(b1,b1Len)){
    498 
    499        //step 4: Remove the ACE Prefix
    500        b1Prime = b1 + ACE_PREFIX_LENGTH;
    501        b1PrimeLen  = b1Len - ACE_PREFIX_LENGTH;
    502 
    503        //step 5: Decode using punycode
    504        UErrorCode bufferStatus = U_ZERO_ERROR;
    505        b2Len = u_strFromPunycode(b1Prime, b1PrimeLen, b2, b2Capacity, caseFlags, &bufferStatus);
    506 
    507        if(bufferStatus == U_BUFFER_OVERFLOW_ERROR){
    508            // redo processing of string
    509            /* we do not have enough room so grow the buffer*/
    510            b2 = static_cast<char16_t*>(uprv_malloc(b2Len * U_SIZEOF_UCHAR));
    511            if(b2==nullptr){
    512                *status = U_MEMORY_ALLOCATION_ERROR;
    513                goto CLEANUP;
    514            }
    515 
    516            bufferStatus = U_ZERO_ERROR; // reset error
    517 
    518            b2Len =  u_strFromPunycode(b1Prime, b1PrimeLen, b2, b2Len, caseFlags, &bufferStatus);
    519        }
    520 
    521 
    522        //step 6:Apply toASCII
    523        b3Len = uidna_toASCII(b2, b2Len, b3, b3Capacity, options, parseError, &bufferStatus);
    524 
    525        if(bufferStatus == U_BUFFER_OVERFLOW_ERROR){
    526            // redo processing of string
    527            /* we do not have enough room so grow the buffer*/
    528            b3 = static_cast<char16_t*>(uprv_malloc(b3Len * U_SIZEOF_UCHAR));
    529            if(b3==nullptr){
    530                *status = U_MEMORY_ALLOCATION_ERROR;
    531                goto CLEANUP;
    532            }
    533 
    534            bufferStatus = U_ZERO_ERROR; // reset error
    535 
    536            b3Len =  uidna_toASCII(b2,b2Len,b3,b3Len,options,parseError,&bufferStatus);
    537 
    538        }
    539        //bail out on error
    540        if(U_FAILURE(bufferStatus)){
    541            *status = bufferStatus;
    542            goto CLEANUP;
    543        }
    544 
    545        //step 7: verify
    546        if(compareCaseInsensitiveASCII(b1, b1Len, b3, b3Len) !=0){
    547            // Cause the original to be returned.
    548            *status = U_IDNA_VERIFICATION_ERROR;
    549            goto CLEANUP;
    550        }
    551 
    552        //step 8: return output of step 5
    553        reqLength = b2Len;
    554        if(b2Len <= destCapacity) {
    555            u_memmove(dest, b2, b2Len);
    556        }
    557    }
    558    else{
    559        // See the start of this if statement for why this is commented out.
    560        // verify that STD3 ASCII rules are satisfied
    561        /*if(useSTD3ASCIIRules == true){
    562            if( srcIsLDH == false // source contains some non-LDH characters
    563                || src[0] ==  HYPHEN || src[srcLength-1] == HYPHEN){
    564                *status = U_IDNA_STD3_ASCII_RULES_ERROR;
    565 
    566                // populate the parseError struct
    567                if(srcIsLDH==false){
    568                    // failPos is always set the index of failure
    569                    uprv_syntaxError(src,failPos, srcLength,parseError);
    570                }else if(src[0] == HYPHEN){
    571                    // fail position is 0 
    572                    uprv_syntaxError(src,0,srcLength,parseError);
    573                }else{
    574                    // the last index in the source is always length-1
    575                    uprv_syntaxError(src, (srcLength>0) ? srcLength-1 : srcLength, srcLength,parseError);
    576                }
    577 
    578                goto CLEANUP;
    579            }
    580        }*/
    581        // just return the source
    582        //copy the source to destination
    583        if(srcLength <= destCapacity){
    584            u_memmove(dest, src, srcLength);
    585        }
    586        reqLength = srcLength;
    587    }
    588 
    589 
    590 CLEANUP:
    591 
    592    if(b1 != b1Stack && b1!=src){
    593        uprv_free(b1);
    594    }
    595    if(b2 != b2Stack){
    596        uprv_free(b2);
    597    }
    598    if(b3 != b3Stack){
    599        uprv_free(b3);
    600    }
    601    uprv_free(caseFlags);
    602 
    603    // The RFC states that 
    604    // <quote>
    605    // ToUnicode never fails. If any step fails, then the original input
    606    // is returned immediately in that step.
    607    // </quote>
    608    // So if any step fails lets copy source to destination
    609    if(U_FAILURE(*status)){
    610        //copy the source to destination
    611        if(dest && srcLength <= destCapacity){
    612            // srcLength should have already been set earlier.
    613            U_ASSERT(srcLength >= 0);
    614            u_memmove(dest, src, srcLength);
    615        }
    616        reqLength = srcLength;
    617        *status = U_ZERO_ERROR;
    618    }
    619 
    620    return u_terminateUChars(dest, destCapacity, reqLength, status);
    621 }
    622 
    623 U_CAPI int32_t U_EXPORT2
    624 uidna_toASCII(const char16_t* src, int32_t srcLength,
    625              char16_t* dest, int32_t destCapacity,
    626              int32_t options,
    627              UParseError* parseError,
    628              UErrorCode* status){
    629    
    630    if(status == nullptr || U_FAILURE(*status)){
    631        return 0;
    632    }
    633    if((src==nullptr) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
    634        *status = U_ILLEGAL_ARGUMENT_ERROR;
    635        return 0;
    636    }
    637 
    638    UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
    639    
    640    if(U_FAILURE(*status)){
    641        return -1;
    642    }
    643    
    644    int32_t retLen = _internal_toASCII(src, srcLength, dest, destCapacity, options, nameprep, parseError, status);
    645    
    646    /* close the profile*/
    647    usprep_close(nameprep);
    648    
    649    return retLen;
    650 }
    651 
    652 U_CAPI int32_t U_EXPORT2
    653 uidna_toUnicode(const char16_t* src, int32_t srcLength,
    654                char16_t* dest, int32_t destCapacity,
    655                int32_t options,
    656                UParseError* parseError,
    657                UErrorCode* status){
    658 
    659    if(status == nullptr || U_FAILURE(*status)){
    660        return 0;
    661    }
    662    if( (src==nullptr) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
    663        *status = U_ILLEGAL_ARGUMENT_ERROR;
    664        return 0;
    665    }  
    666 
    667    UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
    668    
    669    if(U_FAILURE(*status)){
    670        return -1;
    671    }
    672    
    673    int32_t retLen = _internal_toUnicode(src, srcLength, dest, destCapacity, options, nameprep, parseError, status);
    674 
    675    usprep_close(nameprep);
    676    
    677    return retLen;
    678 }
    679 
    680 
    681 U_CAPI int32_t U_EXPORT2
    682 uidna_IDNToASCII(  const char16_t *src, int32_t srcLength,
    683                   char16_t* dest, int32_t destCapacity,
    684                   int32_t options,
    685                   UParseError *parseError,
    686                   UErrorCode *status){
    687 
    688    if(status == nullptr || U_FAILURE(*status)){
    689        return 0;
    690    }
    691    if((src==nullptr) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
    692        *status = U_ILLEGAL_ARGUMENT_ERROR;
    693        return 0;
    694    }
    695 
    696    int32_t reqLength = 0;
    697 
    698    UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
    699    
    700    if(U_FAILURE(*status)){
    701        return 0;
    702    }
    703 
    704    //initialize pointers 
    705    char16_t* delimiter = const_cast<char16_t*>(src);
    706    char16_t* labelStart = const_cast<char16_t*>(src);
    707    char16_t* currentDest = dest;
    708    int32_t remainingLen = srcLength;
    709    int32_t remainingDestCapacity = destCapacity;
    710    int32_t labelLen = 0, labelReqLength = 0;
    711    UBool done = false;
    712 
    713 
    714    for(;;){
    715 
    716        labelLen = getNextSeparator(labelStart,remainingLen, &delimiter,&done);
    717        labelReqLength = 0;
    718        if(!(labelLen==0 && done)){// make sure this is not a root label separator.
    719 
    720            UErrorCode bufferStatus = U_ZERO_ERROR;
    721            labelReqLength = _internal_toASCII( labelStart, labelLen,
    722                                                currentDest, remainingDestCapacity,
    723                                                options, nameprep,
    724                                                parseError, &bufferStatus);
    725 
    726            if (bufferStatus == U_BUFFER_OVERFLOW_ERROR) {
    727                remainingDestCapacity = 0;
    728            } else if (U_FAILURE(bufferStatus)) {
    729                *status = bufferStatus;
    730                break;
    731            }
    732        }
    733 
    734        reqLength +=labelReqLength;
    735        // adjust the destination pointer
    736        if(labelReqLength < remainingDestCapacity){
    737            currentDest = currentDest + labelReqLength;
    738            remainingDestCapacity -= labelReqLength;
    739        }else{
    740            // should never occur
    741            remainingDestCapacity = 0;
    742        }
    743 
    744        if(done){
    745            break;
    746        }
    747 
    748        // add the label separator
    749        if(remainingDestCapacity > 0){
    750            *currentDest++ = FULL_STOP;
    751            remainingDestCapacity--;
    752        }
    753        reqLength++;
    754 
    755        labelStart = delimiter;
    756        if(remainingLen >0 ){
    757            remainingLen = (int32_t)(srcLength - (delimiter - src));
    758        }
    759 
    760    }
    761 
    762    if(reqLength > MAX_DOMAIN_NAME_LENGTH){
    763        *status = U_IDNA_DOMAIN_NAME_TOO_LONG_ERROR;
    764    }
    765 
    766    usprep_close(nameprep);
    767    
    768    return u_terminateUChars(dest, destCapacity, reqLength, status);
    769 }
    770 
    771 U_CAPI int32_t U_EXPORT2
    772 uidna_IDNToUnicode(  const char16_t* src, int32_t srcLength,
    773                     char16_t* dest, int32_t destCapacity,
    774                     int32_t options,
    775                     UParseError* parseError,
    776                     UErrorCode* status){
    777    
    778    if(status == nullptr || U_FAILURE(*status)){
    779        return 0;
    780    }
    781    if((src==nullptr) || (srcLength < -1) || (destCapacity<0) || (!dest && destCapacity > 0)){
    782        *status = U_ILLEGAL_ARGUMENT_ERROR;
    783        return 0;
    784    }
    785 
    786    int32_t reqLength = 0;
    787 
    788    UStringPrepProfile* nameprep = usprep_openByType(USPREP_RFC3491_NAMEPREP, status);
    789    
    790    if(U_FAILURE(*status)){
    791        return 0;
    792    }
    793 
    794    //initialize pointers
    795    char16_t* delimiter = const_cast<char16_t*>(src);
    796    char16_t* labelStart = const_cast<char16_t*>(src);
    797    char16_t* currentDest = dest;
    798    int32_t remainingLen = srcLength;
    799    int32_t remainingDestCapacity = destCapacity;
    800    int32_t labelLen = 0, labelReqLength = 0;
    801    UBool done = false;
    802 
    803    for(;;){
    804 
    805        labelLen = getNextSeparator(labelStart,remainingLen, &delimiter,&done);
    806        
    807        // The RFC states that 
    808        // <quote>
    809        // ToUnicode never fails. If any step fails, then the original input
    810        // is returned immediately in that step.
    811        // </quote>
    812        // _internal_toUnicode will copy the label.
    813        /*if(labelLen==0 && done==false){ 
    814            *status = U_IDNA_ZERO_LENGTH_LABEL_ERROR;
    815            break;
    816        }*/
    817        
    818        labelReqLength = _internal_toUnicode(labelStart, labelLen, 
    819                                             currentDest, remainingDestCapacity, 
    820                                             options, nameprep, 
    821                                             parseError, status);
    822 
    823        if(*status == U_BUFFER_OVERFLOW_ERROR){
    824            *status = U_ZERO_ERROR; // reset error
    825            remainingDestCapacity = 0;
    826        }
    827 
    828        if(U_FAILURE(*status)){
    829            break;
    830        }
    831        
    832        reqLength +=labelReqLength;
    833        // adjust the destination pointer
    834        if(labelReqLength < remainingDestCapacity){
    835            currentDest = currentDest + labelReqLength;
    836            remainingDestCapacity -= labelReqLength;
    837        }else{
    838            // should never occur
    839            remainingDestCapacity = 0;
    840        }
    841 
    842        if(done){
    843            break;
    844        }
    845 
    846        // add the label separator
    847        // Unlike the ToASCII operation we don't normalize the label separators
    848        if(remainingDestCapacity > 0){
    849            *currentDest++ = *(labelStart + labelLen);
    850            remainingDestCapacity--;
    851        }
    852        reqLength++;
    853 
    854        labelStart = delimiter;
    855        if(remainingLen >0 ){
    856            remainingLen = (int32_t)(srcLength - (delimiter - src));
    857        }
    858 
    859    }
    860 
    861    if(reqLength > MAX_DOMAIN_NAME_LENGTH){
    862        *status = U_IDNA_DOMAIN_NAME_TOO_LONG_ERROR;
    863    }
    864 
    865    usprep_close(nameprep);
    866    
    867    return u_terminateUChars(dest, destCapacity, reqLength, status);
    868 }
    869 
    870 U_CAPI int32_t U_EXPORT2
    871 uidna_compare(  const char16_t *s1, int32_t length1,
    872                const char16_t *s2, int32_t length2,
    873                int32_t options,
    874                UErrorCode* status){
    875 
    876    if(status == nullptr || U_FAILURE(*status)){
    877        return -1;
    878    }
    879 
    880    char16_t b1Stack[MAX_IDN_BUFFER_SIZE], b2Stack[MAX_IDN_BUFFER_SIZE];
    881    char16_t *b1 = b1Stack, *b2 = b2Stack;
    882    int32_t b1Len, b2Len, b1Capacity = MAX_IDN_BUFFER_SIZE, b2Capacity = MAX_IDN_BUFFER_SIZE;
    883    int32_t result=-1;
    884    
    885    UParseError parseError;
    886 
    887    UErrorCode bufferStatus = U_ZERO_ERROR;
    888    b1Len = uidna_IDNToASCII(s1, length1, b1, b1Capacity, options, &parseError, &bufferStatus);
    889    if(bufferStatus == U_BUFFER_OVERFLOW_ERROR){
    890        // redo processing of string
    891        b1 = (char16_t*) uprv_malloc(b1Len * U_SIZEOF_UCHAR);
    892        if(b1==nullptr){
    893            *status = U_MEMORY_ALLOCATION_ERROR;
    894            goto CLEANUP;
    895        }
    896 
    897        bufferStatus = U_ZERO_ERROR; // reset error
    898 
    899        b1Len = uidna_IDNToASCII(s1,length1,b1,b1Len, options, &parseError, &bufferStatus);
    900    }
    901 
    902    b2Len = uidna_IDNToASCII(s2,length2, b2,b2Capacity, options, &parseError, &bufferStatus);
    903    if(bufferStatus == U_BUFFER_OVERFLOW_ERROR){
    904        // redo processing of string
    905        b2 = (char16_t*) uprv_malloc(b2Len * U_SIZEOF_UCHAR);
    906        if(b2==nullptr){
    907            *status = U_MEMORY_ALLOCATION_ERROR;
    908            goto CLEANUP;
    909        }
    910 
    911        bufferStatus = U_ZERO_ERROR; // reset error
    912 
    913        b2Len = uidna_IDNToASCII(s2, length2, b2, b2Len, options, &parseError, &bufferStatus);
    914    }
    915 
    916    if (U_FAILURE(bufferStatus)) {
    917        *status = bufferStatus;
    918    }
    919 
    920    // when toASCII is applied all label separators are replaced with FULL_STOP
    921    result = compareCaseInsensitiveASCII(b1,b1Len,b2,b2Len);
    922 
    923 CLEANUP:
    924    if(b1 != b1Stack){
    925        uprv_free(b1);
    926    }
    927 
    928    if(b2 != b2Stack){
    929        uprv_free(b2);
    930    }
    931 
    932    return result;
    933 }
    934 
    935 #endif /* #if !UCONFIG_NO_IDNA */