imapext-2007

annotate src/c-client/utf8aux.c @ 0:ada5e610ab86

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imap-2007e
author yuuji@gentei.org
date Mon, 14 Sep 2009 15:17:45 +0900
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children
rev   line source
yuuji@0 1 /* ========================================================================
yuuji@0 2 * Copyright 1988-2007 University of Washington
yuuji@0 3 *
yuuji@0 4 * Licensed under the Apache License, Version 2.0 (the "License");
yuuji@0 5 * you may not use this file except in compliance with the License.
yuuji@0 6 * You may obtain a copy of the License at
yuuji@0 7 *
yuuji@0 8 * http://www.apache.org/licenses/LICENSE-2.0
yuuji@0 9 *
yuuji@0 10 *
yuuji@0 11 * ========================================================================
yuuji@0 12 */
yuuji@0 13
yuuji@0 14 /*
yuuji@0 15 * Program: UTF-8 auxillary routines (c-client and MIME2 support)
yuuji@0 16 *
yuuji@0 17 * Author: Mark Crispin
yuuji@0 18 * Networks and Distributed Computing
yuuji@0 19 * Computing & Communications
yuuji@0 20 * University of Washington
yuuji@0 21 * Administration Building, AG-44
yuuji@0 22 * Seattle, WA 98195
yuuji@0 23 * Internet: MRC@CAC.Washington.EDU
yuuji@0 24 *
yuuji@0 25 * Date: 11 June 1997
yuuji@0 26 * Last Edited: 12 October 2007
yuuji@0 27 */
yuuji@0 28
yuuji@0 29
yuuji@0 30 #include <stdio.h>
yuuji@0 31 #include <ctype.h>
yuuji@0 32 #include "c-client.h"
yuuji@0 33
yuuji@0 34 /* Convert charset labelled stringlist to UTF-8 in place
yuuji@0 35 * Accepts: string list
yuuji@0 36 * charset
yuuji@0 37 */
yuuji@0 38
yuuji@0 39 static void utf8_stringlist (STRINGLIST *st,char *charset)
yuuji@0 40 {
yuuji@0 41 SIZEDTEXT txt;
yuuji@0 42 /* convert entire stringstruct */
yuuji@0 43 if (st) do if (utf8_text (&st->text,charset,&txt,U8T_CANONICAL)) {
yuuji@0 44 fs_give ((void **) &st->text.data);
yuuji@0 45 st->text.data = txt.data; /* transfer this text */
yuuji@0 46 st->text.size = txt.size;
yuuji@0 47 } while (st = st->next);
yuuji@0 48 }
yuuji@0 49
yuuji@0 50
yuuji@0 51 /* Convert charset labelled searchpgm to UTF-8 in place
yuuji@0 52 * Accepts: search program
yuuji@0 53 * charset
yuuji@0 54 */
yuuji@0 55
yuuji@0 56 void utf8_searchpgm (SEARCHPGM *pgm,char *charset)
yuuji@0 57 {
yuuji@0 58 SIZEDTEXT txt;
yuuji@0 59 SEARCHHEADER *hl;
yuuji@0 60 SEARCHOR *ol;
yuuji@0 61 SEARCHPGMLIST *pl;
yuuji@0 62 if (pgm) { /* must have a search program */
yuuji@0 63 utf8_stringlist (pgm->bcc,charset);
yuuji@0 64 utf8_stringlist (pgm->cc,charset);
yuuji@0 65 utf8_stringlist (pgm->from,charset);
yuuji@0 66 utf8_stringlist (pgm->to,charset);
yuuji@0 67 utf8_stringlist (pgm->subject,charset);
yuuji@0 68 for (hl = pgm->header; hl; hl = hl->next) {
yuuji@0 69 if (utf8_text (&hl->line,charset,&txt,U8T_CANONICAL)) {
yuuji@0 70 fs_give ((void **) &hl->line.data);
yuuji@0 71 hl->line.data = txt.data;
yuuji@0 72 hl->line.size = txt.size;
yuuji@0 73 }
yuuji@0 74 if (utf8_text (&hl->text,charset,&txt,U8T_CANONICAL)) {
yuuji@0 75 fs_give ((void **) &hl->text.data);
yuuji@0 76 hl->text.data = txt.data;
yuuji@0 77 hl->text.size = txt.size;
yuuji@0 78 }
yuuji@0 79 }
yuuji@0 80 utf8_stringlist (pgm->body,charset);
yuuji@0 81 utf8_stringlist (pgm->text,charset);
yuuji@0 82 for (ol = pgm->or; ol; ol = ol->next) {
yuuji@0 83 utf8_searchpgm (ol->first,charset);
yuuji@0 84 utf8_searchpgm (ol->second,charset);
yuuji@0 85 }
yuuji@0 86 for (pl = pgm->not; pl; pl = pl->next) utf8_searchpgm (pl->pgm,charset);
yuuji@0 87 utf8_stringlist (pgm->return_path,charset);
yuuji@0 88 utf8_stringlist (pgm->sender,charset);
yuuji@0 89 utf8_stringlist (pgm->reply_to,charset);
yuuji@0 90 utf8_stringlist (pgm->in_reply_to,charset);
yuuji@0 91 utf8_stringlist (pgm->message_id,charset);
yuuji@0 92 utf8_stringlist (pgm->newsgroups,charset);
yuuji@0 93 utf8_stringlist (pgm->followup_to,charset);
yuuji@0 94 utf8_stringlist (pgm->references,charset);
yuuji@0 95 }
yuuji@0 96 }
yuuji@0 97
yuuji@0 98 /* Convert MIME-2 sized text to UTF-8
yuuji@0 99 * Accepts: source sized text
yuuji@0 100 * charset
yuuji@0 101 * flags (same as utf8_text())
yuuji@0 102 * Returns: T if successful, NIL if failure
yuuji@0 103 */
yuuji@0 104
yuuji@0 105 #define MINENCWORD 9
yuuji@0 106 #define MAXENCWORD 75
yuuji@0 107
yuuji@0 108 /* This resizing algorithm is stupid, but hopefully it should never be triggered
yuuji@0 109 * except for a pathological header. The main concern is that we don't get a
yuuji@0 110 * buffer overflow.
yuuji@0 111 */
yuuji@0 112
yuuji@0 113 #define DSIZE 65536 /* real headers should never be this big */
yuuji@0 114 #define FUZZ 10 /* paranoia fuzz */
yuuji@0 115
yuuji@0 116 long utf8_mime2text (SIZEDTEXT *src,SIZEDTEXT *dst,long flags)
yuuji@0 117 {
yuuji@0 118 unsigned char *s,*se,*e,*ee,*t,*te;
yuuji@0 119 char *cs,*ce,*ls;
yuuji@0 120 SIZEDTEXT txt,rtxt;
yuuji@0 121 unsigned long i;
yuuji@0 122 size_t dsize = min (DSIZE,((src->size / 4) + 1) * 9);
yuuji@0 123 /* always create buffer if canonicalizing */
yuuji@0 124 dst->data = (flags & U8T_CANONICAL) ?
yuuji@0 125 (unsigned char *) fs_get ((size_t) dsize) : NIL;
yuuji@0 126 dst->size = 0; /* nothing written yet */
yuuji@0 127 /* look for encoded words */
yuuji@0 128 for (s = src->data, se = src->data + src->size; s < se; s++) {
yuuji@0 129 if (((se - s) > MINENCWORD) && (*s == '=') && (s[1] == '?') &&
yuuji@0 130 (cs = (char *) mime2_token (s+2,se,(unsigned char **) &ce)) &&
yuuji@0 131 (e = mime2_token ((unsigned char *) ce+1,se,&ee)) &&
yuuji@0 132 (te = mime2_text (t = e+2,se)) && (ee == e + 1) &&
yuuji@0 133 ((te - s) < MAXENCWORD)) {
yuuji@0 134 if (mime2_decode (e,t,te,&txt)) {
yuuji@0 135 *ce = '\0'; /* temporarily tie off charset */
yuuji@0 136 if (ls = strchr (cs,'*')) *ls = '\0';
yuuji@0 137 /* convert to UTF-8 as best we can */
yuuji@0 138 if (!utf8_text (&txt,cs,&rtxt,flags)) utf8_text (&txt,NIL,&rtxt,flags);
yuuji@0 139 if (dst->data) { /* make sure existing buffer fits */
yuuji@0 140 while (dsize <= (dst->size + rtxt.size + FUZZ)) {
yuuji@0 141 dsize += DSIZE; /* kick it up */
yuuji@0 142 fs_resize ((void **) &dst->data,dsize);
yuuji@0 143 }
yuuji@0 144 }
yuuji@0 145 else { /* make a new buffer */
yuuji@0 146 while (dsize <= (dst->size + rtxt.size)) dsize += DSIZE;
yuuji@0 147 memcpy (dst->data = (unsigned char *) fs_get (dsize),src->data,
yuuji@0 148 dst->size = s - src->data);
yuuji@0 149 }
yuuji@0 150 for (i = 0; i < rtxt.size; i++) dst->data[dst->size++] = rtxt.data[i];
yuuji@0 151
yuuji@0 152 /* all done with converted text */
yuuji@0 153 if (rtxt.data != txt.data) fs_give ((void **) &rtxt.data);
yuuji@0 154 if (ls) *ls = '*'; /* restore language tag delimiter */
yuuji@0 155 *ce = '?'; /* restore charset delimiter */
yuuji@0 156 /* all done with decoded text */
yuuji@0 157 fs_give ((void **) &txt.data);
yuuji@0 158 s = te+1; /* continue scan after encoded word */
yuuji@0 159 /* skip leading whitespace */
yuuji@0 160 for (t = s + 1; (t < se) && ((*t == ' ') || (*t == '\t')); t++);
yuuji@0 161 /* see if likely continuation encoded word */
yuuji@0 162 if (t < (se - MINENCWORD)) switch (*t) {
yuuji@0 163 case '=': /* possible encoded word? */
yuuji@0 164 if (t[1] == '?') s = t - 1;
yuuji@0 165 break;
yuuji@0 166 case '\015': /* CR, eat a following LF */
yuuji@0 167 if (t[1] == '\012') t++;
yuuji@0 168 case '\012': /* possible end of logical line */
yuuji@0 169 if ((t[1] == ' ') || (t[1] == '\t')) {
yuuji@0 170 do t++;
yuuji@0 171 while ((t < (se - MINENCWORD)) && ((t[1] == ' ')||(t[1] == '\t')));
yuuji@0 172 if ((t < (se - MINENCWORD)) && (t[1] == '=') && (t[2] == '?'))
yuuji@0 173 s = t; /* definitely looks like continuation */
yuuji@0 174 }
yuuji@0 175 }
yuuji@0 176 }
yuuji@0 177 else { /* restore original text */
yuuji@0 178 if (dst->data) fs_give ((void **) &dst->data);
yuuji@0 179 dst->data = src->data;
yuuji@0 180 dst->size = src->size;
yuuji@0 181 return NIL; /* syntax error: MIME-2 decoding failure */
yuuji@0 182 }
yuuji@0 183 }
yuuji@0 184 else do if (dst->data) { /* stash ASCII characters until LWSP */
yuuji@0 185 if (dsize < (dst->size + FUZZ)) {
yuuji@0 186 dsize += DSIZE; /* kick it up */
yuuji@0 187 fs_resize ((void **) &dst->data,dsize);
yuuji@0 188 }
yuuji@0 189 /* kludge: assumes ASCII doesn't decompose and titlecases to one byte */
yuuji@0 190 dst->data[dst->size++] = (flags & U8T_CASECANON) ?
yuuji@0 191 (unsigned char) ucs4_titlecase (*s) : *s;
yuuji@0 192 }
yuuji@0 193 while ((*s != ' ') && (*s != '\t') && (*s != '\015') && (*s != '\012') &&
yuuji@0 194 (++s < se));
yuuji@0 195 }
yuuji@0 196 if (dst->data) dst->data[dst->size] = '\0';
yuuji@0 197 else { /* nothing converted, return identity */
yuuji@0 198 dst->data = src->data;
yuuji@0 199 dst->size = src->size;
yuuji@0 200 }
yuuji@0 201 return T; /* success */
yuuji@0 202 }
yuuji@0 203
yuuji@0 204 /* Decode MIME-2 text
yuuji@0 205 * Accepts: Encoding
yuuji@0 206 * text
yuuji@0 207 * text end
yuuji@0 208 * destination sized text
yuuji@0 209 * Returns: T if successful, else NIL
yuuji@0 210 */
yuuji@0 211
yuuji@0 212 long mime2_decode (unsigned char *e,unsigned char *t,unsigned char *te,
yuuji@0 213 SIZEDTEXT *txt)
yuuji@0 214 {
yuuji@0 215 unsigned char *q;
yuuji@0 216 txt->data = NIL; /* initially no returned data */
yuuji@0 217 switch (*e) { /* dispatch based upon encoding */
yuuji@0 218 case 'Q': case 'q': /* sort-of QUOTED-PRINTABLE */
yuuji@0 219 txt->data = (unsigned char *) fs_get ((size_t) (te - t) + 1);
yuuji@0 220 for (q = t,txt->size = 0; q < te; q++) switch (*q) {
yuuji@0 221 case '=': /* quoted character */
yuuji@0 222 /* both must be hex */
yuuji@0 223 if (!isxdigit (q[1]) || !isxdigit (q[2])) {
yuuji@0 224 fs_give ((void **) &txt->data);
yuuji@0 225 return NIL; /* syntax error: bad quoted character */
yuuji@0 226 }
yuuji@0 227 /* assemble character */
yuuji@0 228 txt->data[txt->size++] = hex2byte (q[1],q[2]);
yuuji@0 229 q += 2; /* advance past quoted character */
yuuji@0 230 break;
yuuji@0 231 case '_': /* convert to space */
yuuji@0 232 txt->data[txt->size++] = ' ';
yuuji@0 233 break;
yuuji@0 234 default: /* ordinary character */
yuuji@0 235 txt->data[txt->size++] = *q;
yuuji@0 236 break;
yuuji@0 237 }
yuuji@0 238 txt->data[txt->size] = '\0';
yuuji@0 239 break;
yuuji@0 240 case 'B': case 'b': /* BASE64 */
yuuji@0 241 if (txt->data = (unsigned char *) rfc822_base64 (t,te - t,&txt->size))
yuuji@0 242 break;
yuuji@0 243 default: /* any other encoding is unknown */
yuuji@0 244 return NIL; /* syntax error: unknown encoding */
yuuji@0 245 }
yuuji@0 246 return T;
yuuji@0 247 }
yuuji@0 248
yuuji@0 249 /* Get MIME-2 token from encoded word
yuuji@0 250 * Accepts: current text pointer
yuuji@0 251 * text limit pointer
yuuji@0 252 * pointer to returned end pointer
yuuji@0 253 * Returns: current text pointer & end pointer if success, else NIL
yuuji@0 254 */
yuuji@0 255
yuuji@0 256 unsigned char *mime2_token (unsigned char *s,unsigned char *se,
yuuji@0 257 unsigned char **t)
yuuji@0 258 {
yuuji@0 259 for (*t = s; **t != '?'; ++*t) {
yuuji@0 260 if ((*t < se) && isgraph (**t)) switch (**t) {
yuuji@0 261 case '(': case ')': case '<': case '>': case '@': case ',': case ';':
yuuji@0 262 case ':': case '\\': case '"': case '/': case '[': case ']': case '.':
yuuji@0 263 case '=':
yuuji@0 264 return NIL; /* none of these are valid in tokens */
yuuji@0 265 }
yuuji@0 266 else return NIL; /* out of text or CTL or space */
yuuji@0 267 }
yuuji@0 268 return s;
yuuji@0 269 }
yuuji@0 270
yuuji@0 271
yuuji@0 272 /* Get MIME-2 text from encoded word
yuuji@0 273 * Accepts: current text pointer
yuuji@0 274 * text limit pointer
yuuji@0 275 * pointer to returned end pointer
yuuji@0 276 * Returns: end pointer if success, else NIL
yuuji@0 277 */
yuuji@0 278
yuuji@0 279 unsigned char *mime2_text (unsigned char *s,unsigned char *se)
yuuji@0 280 {
yuuji@0 281 unsigned char *t = se - 1;
yuuji@0 282 /* search for closing ?, make sure valid */
yuuji@0 283 while ((s < t) && (*s != '?') && isgraph (*s++));
yuuji@0 284 return ((s < t) && (*s == '?') && (s[1] == '=') &&
yuuji@0 285 ((se == (s + 2)) || (s[2] == ' ') || (s[2] == '\t') ||
yuuji@0 286 (s[2] == '\015') || (s[2] == '\012'))) ? s : NIL;
yuuji@0 287 }
yuuji@0 288
yuuji@0 289 /* Convert UTF-16 string to Modified Base64
yuuji@0 290 * Accepts: destination pointer
yuuji@0 291 * source string
yuuji@0 292 * source length in octets
yuuji@0 293 * Returns: updated destination pointer
yuuji@0 294 */
yuuji@0 295
yuuji@0 296 static unsigned char *utf16_to_mbase64 (unsigned char *t,unsigned char *s,
yuuji@0 297 size_t i)
yuuji@0 298 {
yuuji@0 299 char *v = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
yuuji@0 300 *t++ = '&'; /* write shift-in */
yuuji@0 301 while (i >= 3) { /* process tuplets */
yuuji@0 302 *t++ = v[s[0] >> 2]; /* byte 1: high 6 bits (1) */
yuuji@0 303 /* byte 2: low 2 bits (1), high 4 bits (2) */
yuuji@0 304 *t++ = v[((s[0] << 4) + (s[1] >> 4)) & 0x3f];
yuuji@0 305 /* byte 3: low 4 bits (2), high 2 bits (3) */
yuuji@0 306 *t++ = v[((s[1] << 2) + (s[2] >> 6)) & 0x3f];
yuuji@0 307 *t++ = v[s[2] & 0x3f]; /* byte 4: low 6 bits (3) */
yuuji@0 308 s += 3;
yuuji@0 309 i -= 3;
yuuji@0 310 }
yuuji@0 311 if (i) {
yuuji@0 312 *t++ = v[s[0] >> 2]; /* byte 1: high 6 bits (1) */
yuuji@0 313 /* byte 2: low 2 bits (1), high 4 bits (2) */
yuuji@0 314 *t++ = v[((s[0] << 4) + (--i ? (s[1] >> 4) : 0)) & 0x3f];
yuuji@0 315 /* byte 3: low 4 bits (2) */
yuuji@0 316 if (i) *t++ = v[(s[1] << 2) & 0x3f];
yuuji@0 317 }
yuuji@0 318 *t++ = '-'; /* write shift-out */
yuuji@0 319 return t;
yuuji@0 320 }
yuuji@0 321
yuuji@0 322
yuuji@0 323 /* Poot a UTF-16 value to a buffer
yuuji@0 324 * Accepts: buffer pointer
yuuji@0 325 * value
yuuji@0 326 * Returns: updated pointer
yuuji@0 327 */
yuuji@0 328
yuuji@0 329 static unsigned char *utf16_poot (unsigned char *s,unsigned long c)
yuuji@0 330 {
yuuji@0 331 *s++ = (unsigned char) (c >> 8);
yuuji@0 332 *s++ = (unsigned char) (c & 0xff);
yuuji@0 333 return s;
yuuji@0 334 }
yuuji@0 335
yuuji@0 336 /* Convert UTF-8 to Modified UTF-7
yuuji@0 337 * Accepts: UTF-8 string
yuuji@0 338 * Returns: Modified UTF-7 string on success, NIL if invalid UTF-8
yuuji@0 339 */
yuuji@0 340
yuuji@0 341 #define MAXUNIUTF8 4 /* maximum length of Unicode UTF-8 sequence */
yuuji@0 342
yuuji@0 343 unsigned char *utf8_to_mutf7 (unsigned char *src)
yuuji@0 344 {
yuuji@0 345 unsigned char *u16buf,*utf16;
yuuji@0 346 unsigned char *ret,*t;
yuuji@0 347 unsigned long j,c;
yuuji@0 348 unsigned char *s = src;
yuuji@0 349 unsigned long i = 0;
yuuji@0 350 int nonascii = 0;
yuuji@0 351 while (*s) { /* pass one: count destination octets */
yuuji@0 352 if (*s & 0x80) { /* non-ASCII character? */
yuuji@0 353 j = MAXUNIUTF8; /* get single UCS-4 codepoint */
yuuji@0 354 if ((c = utf8_get (&s,&j)) & U8G_ERROR) return NIL;
yuuji@0 355 /* tally number of UTF-16 octets */
yuuji@0 356 nonascii += (c & U8GM_NONBMP) ? 4 : 2;
yuuji@0 357 }
yuuji@0 358 else { /* ASCII character */
yuuji@0 359 if (nonascii) { /* add pending Modified BASE64 size + shifts */
yuuji@0 360 i += ((nonascii / 3) * 4) + ((j = nonascii % 3) ? j + 1 : 0) + 2;
yuuji@0 361 nonascii = 0; /* back to ASCII */
yuuji@0 362 }
yuuji@0 363 if (*s == '&') i += 2; /* two octets if the escape */
yuuji@0 364 else ++i; /* otherwise just count another octet */
yuuji@0 365 ++s; /* advance to next source octet */
yuuji@0 366 }
yuuji@0 367 }
yuuji@0 368 if (nonascii) /* add pending Modified BASE64 size + shifts */
yuuji@0 369 i += ((nonascii / 3) * 4) + ((j = nonascii % 3) ? j + 1 : 0) + 2;
yuuji@0 370
yuuji@0 371 /* create return buffer */
yuuji@0 372 t = ret = (unsigned char *) fs_get (i + 1);
yuuji@0 373 /* and scratch buffer */
yuuji@0 374 utf16 = u16buf = (unsigned char *) fs_get (i + 1);
yuuji@0 375 for (s = src; *s;) { /* pass two: copy destination octets */
yuuji@0 376 if (*s & 0x80) { /* non-ASCII character? */
yuuji@0 377 j = MAXUNIUTF8; /* get single UCS-4 codepoint */
yuuji@0 378 if ((c = utf8_get (&s,&j)) & U8G_ERROR) return NIL;
yuuji@0 379 if (c & U8GM_NONBMP) { /* non-BMP? */
yuuji@0 380 c -= UTF16_BASE; /* yes, convert to surrogate */
yuuji@0 381 utf16 = utf16_poot (utf16_poot (utf16,(c >> UTF16_SHIFT)+UTF16_SURRH),
yuuji@0 382 (c & UTF16_MASK) + UTF16_SURRL);
yuuji@0 383 }
yuuji@0 384 else utf16 = utf16_poot (utf16,c);
yuuji@0 385 }
yuuji@0 386 else { /* ASCII character */
yuuji@0 387 if (utf16 != u16buf) { /* add pending Modified BASE64 size + shifts */
yuuji@0 388 t = utf16_to_mbase64 (t,u16buf,utf16 - u16buf);
yuuji@0 389 utf16 = u16buf; /* reset buffer */
yuuji@0 390 }
yuuji@0 391 *t++ = *s; /* copy the character */
yuuji@0 392 if (*s == '&') *t++ = '-';/* special sequence if the escape */
yuuji@0 393 ++s; /* advance to next source octet */
yuuji@0 394 }
yuuji@0 395 }
yuuji@0 396 /* add pending Modified BASE64 size + shifts */
yuuji@0 397 if (utf16 != u16buf) t = utf16_to_mbase64 (t,u16buf,utf16 - u16buf);
yuuji@0 398 *t = '\0'; /* tie off destination */
yuuji@0 399 if (i != (t - ret)) fatal ("utf8_to_mutf7 botch");
yuuji@0 400 fs_give ((void **) &u16buf);
yuuji@0 401 return ret;
yuuji@0 402 }
yuuji@0 403
yuuji@0 404 /* Convert Modified UTF-7 to UTF-8
yuuji@0 405 * Accepts: Modified UTF-7 string
yuuji@0 406 * Returns: UTF-8 string on success, NIL if invalid Modified UTF-7
yuuji@0 407 */
yuuji@0 408
yuuji@0 409 unsigned char *utf8_from_mutf7 (unsigned char *src)
yuuji@0 410 {
yuuji@0 411 SIZEDTEXT utf8,utf7;
yuuji@0 412 unsigned char *s;
yuuji@0 413 int mbase64 = 0;
yuuji@0 414 /* disallow bogus strings */
yuuji@0 415 if (mail_utf7_valid (src)) return NIL;
yuuji@0 416 /* initialize SIZEDTEXTs */
yuuji@0 417 memset (&utf7,0,sizeof (SIZEDTEXT));
yuuji@0 418 memset (&utf8,0,sizeof (SIZEDTEXT));
yuuji@0 419 /* make copy of source */
yuuji@0 420 for (s = cpytxt (&utf7,src,strlen (src)); *s; ++s) switch (*s) {
yuuji@0 421 case '&': /* Modified UTF-7 uses & instead of + */
yuuji@0 422 *s = '+';
yuuji@0 423 mbase64 = T; /* note that we are in Modified BASE64 */
yuuji@0 424 break;
yuuji@0 425 case '+': /* temporarily swap text + to & */
yuuji@0 426 if (!mbase64) *s = '&';
yuuji@0 427 break;
yuuji@0 428 case '-': /* shift back to ASCII */
yuuji@0 429 mbase64 = NIL;
yuuji@0 430 break;
yuuji@0 431 case ',': /* Modified UTF-7 uses , instead of / ... */
yuuji@0 432 if (mbase64) *s = '/'; /* ...in Modified BASE64 */
yuuji@0 433 break;
yuuji@0 434 }
yuuji@0 435 /* do the conversion */
yuuji@0 436 utf8_text_utf7 (&utf7,&utf8,NIL,NIL);
yuuji@0 437 /* no longer need copy of source */
yuuji@0 438 fs_give ((void **) &utf7.data);
yuuji@0 439 /* post-process: switch & and + */
yuuji@0 440 for (s = utf8.data; *s; ++s) switch (*s) {
yuuji@0 441 case '&':
yuuji@0 442 *s = '+';
yuuji@0 443 break;
yuuji@0 444 case '+':
yuuji@0 445 *s = '&';
yuuji@0 446 break;
yuuji@0 447 }
yuuji@0 448 return utf8.data;
yuuji@0 449 }

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