2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or (at
5 * your option) any later version.
7 * This program is distributed in the hope that it will be useful, but
8 * WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10 * General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
17 * Copyright © 2006 Pierre Habouzit
21 * Copyright notice from original mutt:
22 * Copyright (C) 1996-2000 Michael R. Elkins <me@mutt.org>
23 * Copyright (C) 2000-2001 Edmund Grimley Evans <edmundo@rano.org>
25 * This file is part of mutt-ng, see http://www.muttng.org/.
26 * It's licensed under the GNU General Public License,
27 * please see the file GPL in the top level source directory.
30 #include <lib-lib/mem.h>
31 #include <lib-lib/str.h>
32 #include <lib-lib/ascii.h>
34 #include <lib-mime/mime.h>
46 /* If you are debugging this file, comment out the following line. */
55 #define ENCWORD_LEN_MAX 75
56 #define ENCWORD_LEN_MIN 9 /* m_strlen("=?.?.?.?=") */
58 #define HSPACE(x) ((x) == '\0' || (x) == ' ' || (x) == '\t')
60 #define CONTINUATION_BYTE(c) (((c) & 0xc0) == 0x80)
62 typedef size_t (*encoder_t) (char *, const char *, size_t,
65 /* converts f of len flen and charset from
66 into *t of len *tlen and charset to
69 returns number of converted chars from f, see iconv(3)
72 convert_string(const char *from, const char *f, ssize_t flen,
73 const char *to, char **t, ssize_t *tlen)
80 cd = mutt_iconv_open(to, from, 0);
82 if (cd == (iconv_t)(-1))
86 ob = buf = p_new(char, obl);
87 n = my_iconv(cd, &f, &flen, &ob, &obl);
89 if (n < 0 || my_iconv(cd, 0, 0, &ob, &obl) < 0) {
100 p_realloc(&buf, ob - buf + 1);
107 char *mutt_choose_charset(const char *fromcode, const char *charsets,
108 char *u, ssize_t ulen, char **d, ssize_t *dlen)
110 char canonical_buff[LONG_STRING];
111 char *e = 0, *tocode = 0;
112 ssize_t elen = 0, bestn = 0;
115 for (p = charsets; p; p = q ? q + 1 : 0) {
121 n = q ? q - p : m_strlen(p);
124 /* Assume that we never need more than 12 characters of
125 encoded-text to encode a single character. */
126 n > (ENCWORD_LEN_MAX - ENCWORD_LEN_MIN + 2 - 12))
131 n = convert_string(fromcode, u, ulen, t, &s, &slen);
135 if (!tocode || n < bestn) {
160 mutt_canonical_charset(canonical_buff, sizeof(canonical_buff), tocode);
161 m_strreplace(&tocode, canonical_buff);
167 static size_t b_encoder (char *s, const char *d, size_t dlen,
172 memcpy (s, "=?", 2), s += 2;
173 memcpy (s, tocode, m_strlen(tocode)), s += m_strlen(tocode);
174 memcpy (s, "?B?", 3), s += 3;
178 else if (dlen == 1) {
179 *s++ = __m_b64chars[(*d >> 2) & 0x3f];
180 *s++ = __m_b64chars[(*d & 0x03) << 4];
185 else if (dlen == 2) {
186 *s++ = __m_b64chars[(*d >> 2) & 0x3f];
187 *s++ = __m_b64chars[((*d & 0x03) << 4) | ((d[1] >> 4) & 0x0f)];
188 *s++ = __m_b64chars[(d[1] & 0x0f) << 2];
193 *s++ = __m_b64chars[(*d >> 2) & 0x3f];
194 *s++ = __m_b64chars[((*d & 0x03) << 4) | ((d[1] >> 4) & 0x0f)];
195 *s++ = __m_b64chars[((d[1] & 0x0f) << 2) | ((d[2] >> 6) & 0x03)];
196 *s++ = __m_b64chars[d[2] & 0x3f];
200 memcpy (s, "?=", 2), s += 2;
204 static size_t q_encoder (char *s, const char *d, size_t dlen,
209 memcpy (s, "=?", 2), s += 2;
210 memcpy (s, tocode, m_strlen(tocode)), s += m_strlen(tocode);
211 memcpy (s, "?Q?", 3), s += 3;
213 unsigned char c = *d++;
217 else if (c >= 0x7f || c < 0x20 || c == '_' || strchr (MimeSpecials, c)) {
219 *s++ = __m_b36chars_upper[c >> 4];
220 *s++ = __m_b36chars_upper[c & 0xf];
225 memcpy (s, "?=", 2), s += 2;
230 * Return 0 if and set *encoder and *wlen if the data (d, dlen) could
231 * be converted to an encoded word of length *wlen using *encoder.
232 * Otherwise return an upper bound on the maximum length of the data
233 * which could be converted.
234 * The data is converted from fromcode (which must be stateless) to
235 * tocode, unless fromcode is 0, in which case the data is assumed to
236 * be already in tocode, which should be 8-bit and stateless.
238 static size_t try_block (const char *d, ssize_t dlen,
239 const char *fromcode, const char *tocode,
240 encoder_t * encoder, ssize_t *wlen)
242 char buf1[ENCWORD_LEN_MAX - ENCWORD_LEN_MIN + 1];
247 int count, len, len_b, len_q;
250 cd = mutt_iconv_open (tocode, fromcode, 0);
251 assert (cd != (iconv_t) (-1));
252 ib = d, ibl = dlen, ob = buf1, obl = sizeof (buf1) - m_strlen(tocode);
253 if (my_iconv(cd, &ib, &ibl, &ob, &obl) < 0
254 || my_iconv(cd, 0, 0, &ob, &obl) < 0)
256 assert (errno == E2BIG);
259 return (ib - d == dlen) ? dlen : ib - d + 1;
264 if (dlen > ssizeof(buf1) - m_strlen(tocode))
265 return ssizeof(buf1) - m_strlen(tocode) + 1;
266 memcpy (buf1, d, dlen);
271 for (p = buf1; p < ob; p++) {
272 unsigned char c = *p;
274 assert (strchr (MimeSpecials, '?'));
275 if (c >= 0x7f || c < 0x20 || *p == '_' ||
276 (c != ' ' && strchr (MimeSpecials, *p)))
280 len = ENCWORD_LEN_MIN - 2 + m_strlen(tocode);
281 len_b = len + (((ob - buf1) + 2) / 3) * 4;
282 len_q = len + (ob - buf1) + 2 * count;
284 /* Apparently RFC 1468 says to use B encoding for iso-2022-jp. */
285 if (!ascii_strcasecmp (tocode, "ISO-2022-JP"))
286 len_q = ENCWORD_LEN_MAX + 1;
288 if (len_b < len_q && len_b <= ENCWORD_LEN_MAX) {
289 *encoder = b_encoder;
293 else if (len_q <= ENCWORD_LEN_MAX) {
294 *encoder = q_encoder;
303 * Encode the data (d, dlen) into s using the encoder.
304 * Return the length of the encoded word.
306 static size_t encode_block (char *s, char *d, ssize_t dlen,
307 const char *fromcode, const char *tocode,
310 char buf1[ENCWORD_LEN_MAX - ENCWORD_LEN_MIN + 1];
311 ssize_t ibl, obl, n1, n2;
317 cd = mutt_iconv_open (tocode, fromcode, 0);
318 assert (cd != (iconv_t) (-1));
319 ib = d, ibl = dlen, ob = buf1, obl = sizeof (buf1) - m_strlen(tocode);
320 n1 = my_iconv(cd, &ib, &ibl, &ob, &obl);
321 n2 = my_iconv(cd, 0, 0, &ob, &obl);
322 assert (n1 >= 0 && n2 >= 0);
324 return (*encoder) (s, buf1, ob - buf1, tocode);
327 return (*encoder) (s, d, dlen, tocode);
331 * Discover how much of the data (d, dlen) can be converted into
332 * a single encoded word. Return how much data can be converted,
333 * and set the length *wlen of the encoded word and *encoder.
334 * We start in column col, which limits the length of the word.
336 static size_t choose_block(char *d, size_t dlen, int col,
337 const char *fromcode, const char *tocode,
338 encoder_t *encoder, ssize_t *wlen)
341 int utf8 = fromcode && !ascii_strcasecmp (fromcode, "UTF-8");
346 nn = try_block (d, n, fromcode, tocode, encoder, wlen);
347 if (!nn && (col + *wlen <= ENCWORD_LEN_MAX + 1 || n <= 1))
349 n = (nn ? nn : n) - 1;
352 while (n > 1 && CONTINUATION_BYTE (d[n]))
359 * Place the result of RFC-2047-encoding (d, dlen) into the dynamically
360 * allocated buffer (e, elen). The input data is in charset fromcode
361 * and is converted into a charset chosen from charsets.
362 * Return 1 if the conversion to UTF-8 failed, 2 if conversion from UTF-8
363 * failed, otherwise 0. If conversion failed, fromcode is assumed to be
364 * compatible with us-ascii and the original data is used.
365 * The input data is assumed to be a single line starting at column col;
366 * if col is non-zero, the preceding character was a space.
368 static int rfc2047_encode (const char *d, ssize_t dlen, int col,
369 const char *fromcode, const char *charsets,
370 char **e, ssize_t *elen, const char *specials)
374 ssize_t bufpos, buflen;
375 char *u, *t0, *t1, *t;
377 ssize_t ulen, r, n, wlen;
381 const char *icode = "UTF-8";
383 /* Try to convert to UTF-8. */
384 if (convert_string(fromcode, d, dlen, icode, &u, &ulen)) {
387 u = p_dupstr(d, ulen = dlen);
390 /* Find earliest and latest things we must encode. */
391 s0 = s1 = t0 = t1 = 0;
392 for (t = u; t < u + ulen; t++) {
394 (*t == '=' && t[1] == '?' && (t == u || HSPACE (*(t - 1))))) {
399 else if (specials && strchr (specials, *t)) {
406 /* If we have something to encode, include RFC822 specials */
407 if (t0 && s0 && s0 < t0)
409 if (t1 && s1 && s1 > t1)
413 /* No encoding is required. */
419 /* Choose target charset. */
422 if ((tocode1 = mutt_choose_charset (icode, charsets, u, ulen, 0, 0)))
428 /* Hack to avoid labelling 8-bit data as us-ascii. */
429 if (!icode && mutt_is_us_ascii (tocode))
430 tocode = "unknown-8bit";
432 /* Adjust t0 for maximum length of line. */
433 t = u + (ENCWORD_LEN_MAX + 1) - col - ENCWORD_LEN_MIN;
440 /* Adjust t0 until we can encode a character after a space. */
441 for (; t0 > u; t0--) {
442 if (!HSPACE (*(t0 - 1)))
446 while (t < u + ulen && CONTINUATION_BYTE (*t))
448 if (!try_block (t0, t - t0, icode, tocode, &encoder, &wlen) &&
449 col + (t0 - u) + wlen <= ENCWORD_LEN_MAX + 1)
453 /* Adjust t1 until we can encode a character before a space. */
454 for (; t1 < u + ulen; t1++) {
459 while (CONTINUATION_BYTE (*t))
461 if (!try_block (t, t1 - t, icode, tocode, &encoder, &wlen) &&
462 1 + wlen + (u + ulen - t1) <= ENCWORD_LEN_MAX + 1)
466 /* We shall encode the region [t0,t1). */
468 /* Initialise the output buffer with the us-ascii prefix. */
470 buf = p_new(char, buflen);
472 memcpy (buf, u, t0 - u);
478 /* Find how much we can encode. */
479 n = choose_block (t, t1 - t, col, icode, tocode, &encoder, &wlen);
481 /* See if we can fit the us-ascii suffix, too. */
482 if (col + wlen + (u + ulen - t1) <= ENCWORD_LEN_MAX + 1)
486 while (CONTINUATION_BYTE (t[n]))
490 /* This should only happen in the really stupid case where the
491 only word that needs encoding is one character long, but
492 there is too much us-ascii stuff after it to use a single
493 encoded word. We add the next word to the encoded region
495 assert (t1 < u + ulen);
496 for (t1++; t1 < u + ulen && !HSPACE (*t1); t1++);
499 n = choose_block (t, n, col, icode, tocode, &encoder, &wlen);
502 /* Add to output buffer. */
503 #define LINEBREAK "\n\t"
504 if (bufpos + wlen + m_strlen(LINEBREAK) > buflen) {
505 buflen = bufpos + wlen + m_strlen(LINEBREAK);
506 p_realloc(&buf, buflen);
508 r = encode_block (buf + bufpos, t, n, icode, tocode, encoder);
511 memcpy (buf + bufpos, LINEBREAK, m_strlen(LINEBREAK));
512 bufpos += m_strlen(LINEBREAK);
520 /* Add last encoded word and us-ascii suffix to buffer. */
521 buflen = bufpos + wlen + (u + ulen - t1);
522 p_realloc(&buf, buflen + 1);
523 r = encode_block (buf + bufpos, t, t1 - t, icode, tocode, encoder);
526 memcpy (buf + bufpos, t1, u + ulen - t1);
538 void _rfc2047_encode_string (char **pd, int encode_specials, int col)
542 const char *charsets;
544 if (!Charset || !*pd)
547 charsets = SendCharset;
548 if (!charsets || !*charsets)
551 rfc2047_encode (*pd, m_strlen(*pd), col,
552 Charset, charsets, &e, &elen,
553 encode_specials ? RFC822Specials : NULL);
559 void rfc2047_encode_string(char **pd) {
560 _rfc2047_encode_string(pd, 0, 32);
563 void rfc2047_encode_adrlist (address_t * addr, const char *tag)
565 address_t *ptr = addr;
566 int col = tag ? m_strlen(tag) + 2 : 32;
570 _rfc2047_encode_string (&ptr->personal, 1, col);
575 static int rfc2047_decode_word (char *d, const char *s, size_t len)
577 const char *pp, *pp1;
580 int enc = 0, count = 0;
581 char *charset = NULL;
583 pd = d0 = p_new(char, m_strlen(s));
585 for (pp = s; (pp1 = strchr (pp, '?')); pp = pp1 + 1) {
589 /* ignore language specification a la RFC 2231 */
591 if ((t1 = memchr (pp, '*', t - pp)))
593 charset = p_dupstr(pp, t - pp);
596 if (toupper ((unsigned char) *pp) == 'Q')
597 enc = ENCQUOTEDPRINTABLE;
598 else if (toupper ((unsigned char) *pp) == 'B')
607 if (enc == ENCQUOTEDPRINTABLE) {
608 for (; pp < pp1; pp++) {
611 else if (*pp == '=' && hexval(pp[1]) >= 0 && hexval(pp[2]) >= 0) {
612 *pd++ = (hexval (pp[1]) << 4) | hexval (pp[2]);
620 else if (enc == ENCBASE64) {
623 for (; pp < pp1; pp++) {
626 if ((c = base64val(*pp)) < 0)
630 *pd++ = b | (c >> k);
645 mutt_convert_string (&d0, charset, Charset, M_ICONV_HOOK_FROM);
646 m_strcpy(d, len, d0);
653 * Find the start and end of the first encoded word in the string.
654 * We use the grammar in section 2 of RFC 2047, but the "encoding"
655 * must be B or Q. Also, we don't require the encoded word to be
656 * separated by linear-white-space (section 5(1)).
658 static const char *find_encoded_word (const char *s, const char **x)
663 while ((p = strstr (q, "=?"))) {
665 0x20 < *q && *q < 0x7f && !strchr ("()<>@,;:\"/[]?.=", *q); q++);
666 if (q[0] != '?' || !strchr ("BbQq", q[1]) || q[2] != '?')
668 for (q = q + 3; 0x20 <= *q && *q < 0x7f && *q != '?'; q++);
669 if (q[0] != '?' || q[1] != '=') {
681 /* return length of linear white space */
682 static size_t lwslen (const char *s, size_t n)
690 for (; p < s + n; p++)
691 if (!strchr (" \t\r\n", *p)) {
692 len = (size_t) (p - s);
695 if (strchr ("\r\n", *(p - 1))) /* LWS doesn't end with CRLF */
700 /* return length of linear white space : reverse */
701 static size_t lwsrlen (const char *s, size_t n)
703 const char *p = s + n - 1;
709 if (strchr ("\r\n", *p)) /* LWS doesn't end with CRLF */
713 if (!strchr (" \t\r\n", *p)) {
714 len = (size_t) (s + n - 1 - p);
720 /* try to decode anything that looks like a valid RFC2047 encoded
721 * header field, ignoring RFC822 parsing rules
723 void rfc2047_decode (char **pd)
727 int found_encoded = 0;
735 dlen = 4 * m_strlen(s); /* should be enough */
736 d = d0 = p_new(char, dlen + 1);
738 while (*s && dlen > 0) {
739 if (!(p = find_encoded_word (s, &q))) {
740 /* no encoded words */
741 if (!option (OPTSTRICTMIME)) {
743 if (found_encoded && (m = lwslen (s, n)) != 0) {
745 *d = ' ', d++, dlen--;
748 if (ascii_strcasecmp (AssumedCharset, "us-ascii")) {
753 if (mutt_convert_nonmime_string (&t) == 0) {
755 strncpy (d, t, tlen);
766 strncpy (d, s, dlen);
772 n = (size_t) (p - s);
773 /* ignore spaces between encoded words
774 * and linear white spaces between encoded word and *text */
775 if (!option (OPTSTRICTMIME)) {
776 if (found_encoded && (m = lwslen (s, n)) != 0) {
778 *d = ' ', d++, dlen--;
782 if ((m = n - lwsrlen (s, n)) != 0) {
789 *d = ' ', d++, dlen--;
792 else if (!found_encoded || strspn (s, " \t\r\n") != n) {
801 rfc2047_decode_word (d, p, dlen);
815 void rfc2047_decode_adrlist (address_t * a)
819 rfc2047_decode (&a->personal);
824 void rfc2047_decode_envelope (ENVELOPE* e) {
829 /* do RFC2047 decoding */
830 rfc2047_decode_adrlist (e->from);
831 rfc2047_decode_adrlist (e->to);
832 rfc2047_decode_adrlist (e->cc);
833 rfc2047_decode_adrlist (e->bcc);
834 rfc2047_decode_adrlist (e->reply_to);
835 rfc2047_decode_adrlist (e->mail_followup_to);
836 rfc2047_decode_adrlist (e->return_path);
837 rfc2047_decode_adrlist (e->sender);
840 rfc2047_decode (&e->subject);
841 mutt_adjust_subject (e);