Annotation of embedaddon/libiconv/lib/utf7.h, revision 1.1.1.2

1.1       misho       1: /*
1.1.1.2 ! misho       2:  * Copyright (C) 1999-2001, 2008, 2016 Free Software Foundation, Inc.
1.1       misho       3:  * This file is part of the GNU LIBICONV Library.
                      4:  *
                      5:  * The GNU LIBICONV Library is free software; you can redistribute it
                      6:  * and/or modify it under the terms of the GNU Library General Public
                      7:  * License as published by the Free Software Foundation; either version 2
                      8:  * of the License, or (at your option) any later version.
                      9:  *
                     10:  * The GNU LIBICONV Library is distributed in the hope that it will be
                     11:  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
                     12:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
                     13:  * Library General Public License for more details.
                     14:  *
                     15:  * You should have received a copy of the GNU Library General Public
                     16:  * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
1.1.1.2 ! misho      17:  * If not, see <https://www.gnu.org/licenses/>.
1.1       misho      18:  */
                     19: 
                     20: /*
                     21:  * UTF-7
                     22:  */
                     23: 
                     24: /* Specification: RFC 2152 (and old RFC 1641, RFC 1642) */
                     25: /* The original Base64 encoding is defined in RFC 2045. */
                     26: 
                     27: /* Set of direct characters:
                     28:  *   A-Z a-z 0-9 ' ( ) , - . / : ? space tab lf cr
                     29:  */
                     30: static const unsigned char direct_tab[128/8] = {
                     31:   0x00, 0x26, 0x00, 0x00, 0x81, 0xf3, 0xff, 0x87,
                     32:   0xfe, 0xff, 0xff, 0x07, 0xfe, 0xff, 0xff, 0x07,
                     33: };
                     34: #define isdirect(ch) ((ch) < 128 && ((direct_tab[(ch)>>3] >> (ch & 7)) & 1))
                     35: 
                     36: /* Set of direct and optional direct characters:
                     37:  *   A-Z a-z 0-9 ' ( ) , - . / : ? space tab lf cr
                     38:  *   ! " # $ % & * ; < = > @ [ ] ^ _ ` { | }
                     39:  */
                     40: static const unsigned char xdirect_tab[128/8] = {
                     41:   0x00, 0x26, 0x00, 0x00, 0xff, 0xf7, 0xff, 0xff,
                     42:   0xff, 0xff, 0xff, 0xef, 0xff, 0xff, 0xff, 0x3f,
                     43: };
                     44: #define isxdirect(ch) ((ch) < 128 && ((xdirect_tab[(ch)>>3] >> (ch & 7)) & 1))
                     45: 
                     46: /* Set of base64 characters, extended:
                     47:  *   A-Z a-z 0-9 + / -
                     48:  */
                     49: static const unsigned char xbase64_tab[128/8] = {
                     50:   0x00, 0x00, 0x00, 0x00, 0x00, 0xa8, 0xff, 0x03,
                     51:   0xfe, 0xff, 0xff, 0x07, 0xfe, 0xff, 0xff, 0x07,
                     52: };
                     53: #define isxbase64(ch) ((ch) < 128 && ((xbase64_tab[(ch)>>3] >> (ch & 7)) & 1))
                     54: 
                     55: /*
                     56:  * The state is structured as follows:
                     57:  * bit 1..0: shift
                     58:  * bit 7..2: data
                     59:  * Precise meaning:
                     60:  *   shift      data
                     61:  *     0         0           not inside base64 encoding
                     62:  *     1         0           inside base64, no pending bits
                     63:  *     2      XXXX00         inside base64, 4 bits remain from 2nd byte
                     64:  *     3      XX0000         inside base64, 2 bits remain from 3rd byte
                     65:  */
                     66: 
                     67: static int
1.1.1.2 ! misho      68: utf7_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, size_t n)
1.1       misho      69: {
                     70:   state_t state = conv->istate;
                     71:   int count = 0; /* number of input bytes already read */
                     72:   if (state & 3)
                     73:     goto active;
                     74:   else
                     75:     goto inactive;
                     76: 
                     77: inactive:
                     78:   {
                     79:     /* Here (state & 3) == 0 */
                     80:     if (n < count+1)
                     81:       goto none;
                     82:     {
                     83:       unsigned char c = *s;
                     84:       if (isxdirect(c)) {
                     85:         *pwc = (ucs4_t) c;
                     86:         conv->istate = state;
                     87:         return count+1;
                     88:       }
                     89:       if (c == '+') {
                     90:         if (n < count+2)
                     91:           goto none;
                     92:         if (s[1] == '-') {
                     93:           *pwc = (ucs4_t) '+';
                     94:           conv->istate = state;
                     95:           return count+2;
                     96:         }
                     97:         s++; count++;
                     98:         state = 1;
                     99:         goto active;
                    100:       }
                    101:       goto ilseq;
                    102:     }
                    103:   }
                    104: 
                    105: active:
                    106:   {
                    107:     /* base64 encoding active */
                    108:     unsigned int wc = 0;
                    109:     state_t base64state = state;
                    110:     unsigned int kmax = 2; /* number of payload bytes to read */
                    111:     unsigned int k = 0; /* number of payload bytes already read */
                    112:     unsigned int base64count = 0; /* number of base64 bytes already read */
                    113:     for (;;) {
                    114:       unsigned char c = *s;
                    115:       unsigned int i;
                    116:       if (c >= 'A' && c <= 'Z')
                    117:         i = c-'A';
                    118:       else if (c >= 'a' && c <= 'z')
                    119:         i = c-'a'+26;
                    120:       else if (c >= '0' && c <= '9')
                    121:         i = c-'0'+52;
                    122:       else if (c == '+')
                    123:         i = 62;
                    124:       else if (c == '/')
                    125:         i = 63;
                    126:       else {
                    127:         /* c terminates base64 encoding */
                    128:         if (base64state & -4)
                    129:           goto ilseq; /* data must be 0, otherwise illegal */
                    130:         if (base64count)
                    131:           goto ilseq; /* partial UTF-16 characters are invalid */
                    132:         if (c == '-') {
                    133:           s++; count++;
                    134:         }
                    135:         state = 0;
                    136:         goto inactive;
                    137:       }
                    138:       s++; base64count++;
                    139:       /* read 6 bits: 0 <= i < 64 */
                    140:       switch (base64state & 3) {
                    141:         case 1: /* inside base64, no pending bits */
                    142:           base64state = (i << 2) | 0; break;
                    143:         case 0: /* inside base64, 6 bits remain from 1st byte */
                    144:           wc = (wc << 8) | (base64state & -4) | (i >> 4); k++;
                    145:           base64state = ((i & 15) << 4) | 2; break;
                    146:         case 2: /* inside base64, 4 bits remain from 2nd byte */
                    147:           wc = (wc << 8) | (base64state & -4) | (i >> 2); k++;
                    148:           base64state = ((i & 3) << 6) | 3; break;
                    149:         case 3: /* inside base64, 2 bits remain from 3rd byte */
                    150:           wc = (wc << 8) | (base64state & -4) | i; k++;
                    151:           base64state = 1; break;
                    152:       }
                    153:       if (k == kmax) {
                    154:         /* UTF-16: When we see a High Surrogate, we must also decode
                    155:            the following Low Surrogate. */
                    156:         if (kmax == 2 && (wc >= 0xd800 && wc < 0xdc00))
                    157:           kmax = 4;
                    158:         else
                    159:           break;
                    160:       }
                    161:       if (n < count+base64count+1)
                    162:         goto none;
                    163:     }
                    164:     /* Here k = kmax > 0, hence base64count > 0. */
                    165:     if ((base64state & 3) == 0) abort();
                    166:     if (kmax == 4) {
                    167:       ucs4_t wc1 = wc >> 16;
                    168:       ucs4_t wc2 = wc & 0xffff;
                    169:       if (!(wc1 >= 0xd800 && wc1 < 0xdc00)) abort();
                    170:       if (!(wc2 >= 0xdc00 && wc2 < 0xe000)) goto ilseq;
                    171:       *pwc = 0x10000 + ((wc1 - 0xd800) << 10) + (wc2 - 0xdc00);
                    172:     } else {
                    173:       *pwc = wc;
                    174:     }
                    175:     conv->istate = base64state;
                    176:     return count+base64count;
                    177:   }
                    178: 
                    179: none:
                    180:   conv->istate = state;
                    181:   return RET_TOOFEW(count);
                    182: 
                    183: ilseq:
                    184:   conv->istate = state;
                    185:   return RET_SHIFT_ILSEQ(count);
                    186: }
                    187: 
                    188: /*
                    189:  * The state is structured as follows:
                    190:  * bit 1..0: shift
                    191:  * bit 7..2: data
                    192:  * Precise meaning:
                    193:  *   shift      data
                    194:  *     0         0           not inside base64 encoding
                    195:  *     1         0           inside base64, no pending bits
                    196:  *     2       XX00          inside base64, 2 bits known for 2nd byte
                    197:  *     3       XXXX          inside base64, 4 bits known for 3rd byte
                    198:  */
                    199: 
                    200: /* Define this to 1 if you want the so-called "optional direct" characters
                    201:       ! " # $ % & * ; < = > @ [ ] ^ _ ` { | }
                    202:    to be encoded. Define to 0 if you want them to be passed straight through,
                    203:    like the so-called "direct" characters.
                    204:    We set this to 1 because it's safer.
                    205:  */
                    206: #define UTF7_ENCODE_OPTIONAL_CHARS 1
                    207: 
                    208: static int
1.1.1.2 ! misho     209: utf7_wctomb (conv_t conv, unsigned char *r, ucs4_t iwc, size_t n)
1.1       misho     210: {
                    211:   state_t state = conv->ostate;
                    212:   unsigned int wc = iwc;
                    213:   int count = 0;
                    214:   if (state & 3)
                    215:     goto active;
                    216: 
                    217: /*inactive:*/
                    218:   {
                    219:     if (UTF7_ENCODE_OPTIONAL_CHARS ? isdirect(wc) : isxdirect(wc)) {
                    220:       r[0] = (unsigned char) wc;
                    221:       /*conv->ostate = state;*/
                    222:       return 1;
                    223:     } else {
                    224:       *r++ = '+';
                    225:       if (wc == '+') {
                    226:         if (n < 2)
                    227:           return RET_TOOSMALL;
                    228:         *r = '-';
                    229:         /*conv->ostate = state;*/
                    230:         return 2;
                    231:       }
                    232:       count = 1;
                    233:       state = 1;
                    234:       goto active;
                    235:     }
                    236:   }
                    237: 
                    238: active:
                    239:   {
                    240:     /* base64 encoding active */
                    241:     if (UTF7_ENCODE_OPTIONAL_CHARS ? isdirect(wc) : isxdirect(wc)) {
                    242:       /* deactivate base64 encoding */
                    243:       count += ((state & 3) >= 2 ? 1 : 0) + (isxbase64(wc) ? 1 : 0) + 1;
                    244:       if (n < count)
                    245:         return RET_TOOSMALL;
                    246:       if ((state & 3) >= 2) {
                    247:         unsigned int i = state & -4;
                    248:         unsigned char c;
                    249:         if (i < 26)
                    250:           c = i+'A';
                    251:         else if (i < 52)
                    252:           c = i-26+'a';
                    253:         else if (i < 62)
                    254:           c = i-52+'0';
                    255:         else if (i == 62)
                    256:           c = '+';
                    257:         else if (i == 63)
                    258:           c = '/';
                    259:         else
                    260:           abort();
                    261:         *r++ = c;
                    262:       }
                    263:       if (isxbase64(wc))
                    264:         *r++ = '-';
                    265:       state = 0;
                    266:       *r++ = (unsigned char) wc;
                    267:       conv->ostate = state;
                    268:       return count;
                    269:     } else {
                    270:       unsigned int k; /* number of payload bytes to write */
                    271:       if (wc < 0x10000) {
                    272:         k = 2;
                    273:         count += ((state & 3) >= 2 ? 3 : 2);
                    274:       } else if (wc < 0x110000) {
                    275:         unsigned int wc1 = 0xd800 + ((wc - 0x10000) >> 10);
                    276:         unsigned int wc2 = 0xdc00 + ((wc - 0x10000) & 0x3ff);
                    277:         wc = (wc1 << 16) | wc2;
                    278:         k = 4;
                    279:         count += ((state & 3) >= 3 ? 6 : 5);
                    280:       } else
                    281:         return RET_ILUNI;
                    282:       if (n < count)
                    283:         return RET_TOOSMALL;
                    284:       for (;;) {
                    285:         unsigned int i;
                    286:         unsigned char c;
                    287:         switch (state & 3) {
                    288:           case 0: /* inside base64, 6 bits known for 4th byte */
                    289:             c = (state & -4) >> 2; state = 1; break;
                    290:           case 1: /* inside base64, no pending bits */
                    291:             i = (wc >> (8 * --k)) & 0xff;
                    292:             c = i >> 2; state = ((i & 3) << 4) | 2; break;
                    293:           case 2: /* inside base64, 2 bits known for 2nd byte */
                    294:             i = (wc >> (8 * --k)) & 0xff;
                    295:             c = (state & -4) | (i >> 4); state = ((i & 15) << 2) | 3; break;
                    296:           case 3: /* inside base64, 4 bits known for 3rd byte */
                    297:             i = (wc >> (8 * --k)) & 0xff;
                    298:             c = (state & -4) | (i >> 6); state = ((i & 63) << 2) | 0; break;
                    299:           default: abort(); /* stupid gcc */
                    300:         }
                    301:         if (c < 26)
                    302:           c = c+'A';
                    303:         else if (c < 52)
                    304:           c = c-26+'a';
                    305:         else if (c < 62)
                    306:           c = c-52+'0';
                    307:         else if (c == 62)
                    308:           c = '+';
                    309:         else if (c == 63)
                    310:           c = '/';
                    311:         else
                    312:           abort();
                    313:         *r++ = c;
                    314:         if ((state & 3) && (k == 0))
                    315:           break;
                    316:       }
                    317:       conv->ostate = state;
                    318:       return count;
                    319:     }
                    320:   }
                    321: }
                    322: 
                    323: static int
1.1.1.2 ! misho     324: utf7_reset (conv_t conv, unsigned char *r, size_t n)
1.1       misho     325: {
                    326:   state_t state = conv->ostate;
                    327:   if (state & 3) {
                    328:     /* deactivate base64 encoding */
                    329:     unsigned int count = ((state & 3) >= 2 ? 1 : 0) + 1;
                    330:     if (n < count)
                    331:       return RET_TOOSMALL;
                    332:     if ((state & 3) >= 2) {
                    333:       unsigned int i = state & -4;
                    334:       unsigned char c;
                    335:       if (i < 26)
                    336:         c = i+'A';
                    337:       else if (i < 52)
                    338:         c = i-26+'a';
                    339:       else if (i < 62)
                    340:         c = i-52+'0';
                    341:       else if (i == 62)
                    342:         c = '+';
                    343:       else if (i == 63)
                    344:         c = '/';
                    345:       else
                    346:         abort();
                    347:       *r++ = c;
                    348:     }
                    349:     *r++ = '-';
                    350:     /* conv->ostate = 0; will be done by the caller */
                    351:     return count;
                    352:   } else
                    353:     return 0;
                    354: }

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