-
-/*
- * fmt_rfc2047.c -- decode RFC-2047 header format
- *
- * $Id$
+/* fmt_rfc2047.c -- decode RFC-2047 header format
*
* This code is Copyright (c) 2002, by the authors of nmh. See the
* COPYRIGHT file in the root directory of the nmh distribution for
*/
#include <h/mh.h>
+#include <h/utils.h>
+#ifdef HAVE_ICONV
+# include <iconv.h>
+#endif
-static signed char hexindex[] = {
+static const signed char hexindex[] = {
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
};
-static signed char index_64[128] = {
+static const signed char index_64[128] = {
-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
#define char64(c) (((unsigned char) (c) > 127) ? -1 : index_64[(unsigned char) (c)])
-static int
-unqp (unsigned char byte1, unsigned char byte2)
+/*
+ * Decode two quoted-pair characters
+ */
+
+int
+decode_qp (unsigned char byte1, unsigned char byte2)
{
if (hexindex[byte1] == -1 || hexindex[byte2] == -1)
return -1;
- return (hexindex[byte1] << 4 | hexindex[byte2]);
+ return hexindex[byte1] << 4 | hexindex[byte2];
}
/* Check if character is linear whitespace */
* Decode the string as a RFC-2047 header field
*/
+/* Add character to the destination buffer, and bomb out if it fills up */
+#define ADDCHR(C) do { *q++ = (C); dstlen--; if (!dstlen) goto buffull; } while (0)
+
int
-decode_rfc2047 (char *str, char *dst)
+decode_rfc2047 (char *str, char *dst, size_t dstlen)
{
char *p, *q, *pp;
- char *startofmime, *endofmime;
+ char *startofmime, *endofmime, *endofcharset;
int c, quoted_printable;
int encoding_found = 0; /* did we decode anything? */
int between_encodings = 0; /* are we between two encodings? */
int equals_pending = 0; /* is there a '=' pending? */
int whitespace = 0; /* how much whitespace between encodings? */
+#ifdef HAVE_ICONV
+ int use_iconv = 0; /* are we converting encoding with iconv? */
+ iconv_t cd = NULL;
+ int fromutf8 = 0;
+ char *saveq, *convbuf = NULL;
+ size_t savedstlen;
+#endif
if (!str)
return 0;
return 0;
for (p = str, q = dst; *p; p++) {
+
+ /* reset iconv */
+#ifdef HAVE_ICONV
+ if (use_iconv) {
+ iconv_close(cd);
+ use_iconv = 0;
+ }
+#endif
/*
* If we had an '=' character pending from
* last iteration, then add it first.
*/
if (equals_pending) {
- *q++ = '=';
+ ADDCHR('=');
equals_pending = 0;
between_encodings = 0; /* we have added non-whitespace text */
}
whitespace++;
else
between_encodings = 0; /* we have added non-whitespace text */
- *q++ = *p;
+ ADDCHR(*p);
continue;
}
equals_pending = 1; /* we have a '=' pending */
/* Check for initial =? */
- if (*p == '=' && p[1] && p[1] == '?' && p[2]) {
+ if (*p == '=' && p[1] == '?' && p[2]) {
startofmime = p + 2;
/* Scan ahead for the next '?' character */
if (!*pp)
continue;
- /* Check if character set is OK */
- if (!check_charset(startofmime, pp - startofmime))
+ /*
+ * RFC 2231 specifies that language information can appear
+ * in a charset specification like so:
+ *
+ * =?us-ascii*en?Q?Foo?=
+ *
+ * Right now we don't use language information, so ignore it.
+ */
+
+ for (endofcharset = startofmime;
+ *endofcharset != '*' && endofcharset < pp;
+ endofcharset++)
+ ;
+
+ /* Check if character set can be handled natively */
+ if (!check_charset(startofmime, endofcharset - startofmime)) {
+#ifdef HAVE_ICONV
+ /* .. it can't. We'll use iconv then. */
+ *endofcharset = '\0';
+ cd = iconv_open(get_charset(), startofmime);
+ fromutf8 = !strcasecmp(startofmime, "UTF-8");
+ *pp = '?';
+ if (cd == (iconv_t)-1) continue;
+ use_iconv = 1;
+#else
continue;
+#endif
+ }
startofmime = pp + 1;
*/
endofmime = NULL;
for (pp = startofmime; *pp && *(pp+1); pp++) {
- if (is_lws(*pp)) {
+ if (is_lws(*pp))
break;
- } else if (*pp == '?' && pp[1] == '=') {
+ if (*pp == '?' && pp[1] == '=') {
endofmime = pp;
break;
}
* We will roll back the buffer the number of whitespace
* characters we've seen since last encoded word.
*/
- if (between_encodings)
+ if (between_encodings) {
q -= whitespace;
+ dstlen += whitespace;
+ }
+
+#ifdef HAVE_ICONV
+ /*
+ * empty encoded text. This ensures that we don't
+ * malloc 0 bytes but skip on to the end
+ */
+ if (endofmime == startofmime && use_iconv) {
+ use_iconv = 0;
+ iconv_close(cd);
+ }
+
+ if (use_iconv) {
+ saveq = q;
+ savedstlen = dstlen;
+ q = convbuf = mh_xmalloc(endofmime - startofmime);
+ }
+/* ADDCHR2 is for adding characters when q is or might be convbuf:
+ * in this case on buffer-full we want to run iconv before returning.
+ * I apologise for the dreadful name.
+ */
+#define ADDCHR2(C) do { *q++ = (C); dstlen--; if (!dstlen) goto iconvbuffull; } while (0)
+#else
+#define ADDCHR2(C) ADDCHR(C)
+#endif
/* Now decode the text */
if (quoted_printable) {
for (pp = startofmime; pp < endofmime; pp++) {
if (*pp == '=') {
- c = unqp (pp[1], pp[2]);
+ c = decode_qp (pp[1], pp[2]);
if (c == -1)
continue;
if (c != 0)
*q++ = c;
pp += 2;
} else if (*pp == '_') {
- *q++ = ' ';
+ ADDCHR2(' ');
} else {
- *q++ = *pp;
+ ADDCHR2(*pp);
}
}
} else {
/* base64 */
int c1, c2, c3, c4;
+ c1 = c2 = c3 = c4 = -1;
pp = startofmime;
while (pp < endofmime) {
pp++;
}
if (pp < endofmime && c1 != -1 && c2 != -1) {
- *q++ = (c1 << 2) | (c2 >> 4);
+ ADDCHR2((c1 << 2) | (c2 >> 4));
pp++;
}
/* 4 + 4 bits */
pp++;
}
if (pp < endofmime && c2 != -1 && c3 != -1) {
- *q++ = ((c2 & 0xF) << 4) | (c3 >> 2);
+ ADDCHR2(((c2 & 0xF) << 4) | (c3 >> 2));
pp++;
}
/* 2 + 6 bits */
pp++;
}
if (pp < endofmime && c3 != -1 && c4 != -1) {
- *q++ = ((c3 & 0x3) << 6) | (c4);
+ ADDCHR2(((c3 & 0x3) << 6) | (c4));
pp++;
}
}
}
+#ifdef HAVE_ICONV
+ iconvbuffull:
+ /* NB that the string at convbuf is not necessarily NUL terminated here:
+ * q points to the first byte after the valid part.
+ */
+ /* Convert to native character set */
+ if (use_iconv) {
+ size_t inbytes = q - convbuf;
+ ICONV_CONST char *start = convbuf;
+
+ while (inbytes) {
+ if (iconv(cd, &start, &inbytes, &saveq, &savedstlen) ==
+ (size_t)-1) {
+ if (errno != EILSEQ) break;
+ /* character couldn't be converted. we output a `?'
+ * and try to carry on which won't work if
+ * either encoding was stateful */
+ iconv (cd, 0, 0, &saveq, &savedstlen);
+ if (!savedstlen)
+ break;
+ *saveq++ = '?';
+ savedstlen--;
+ if (!savedstlen)
+ break;
+ /* skip to next input character */
+ if (fromutf8) {
+ for (++start, --inbytes;
+ start < q && (*start & 192) == 128;
+ ++start, --inbytes)
+ continue;
+ } else
+ start++, inbytes--;
+ if (start >= q)
+ break;
+ }
+ }
+ q = saveq;
+ /* Stop now if (1) we hit the end of the buffer trying to do
+ * MIME decoding and have just iconv-converted a partial string
+ * or (2) our iconv-conversion hit the end of the buffer.
+ */
+ if (!dstlen || !savedstlen)
+ goto buffull;
+ dstlen = savedstlen;
+ free(convbuf);
+ }
+#endif
+
/*
* Now that we are done decoding this particular
* encoded word, advance string to trailing '='.
whitespace = 0; /* re-initialize amount of whitespace */
}
}
+#ifdef HAVE_ICONV
+ if (use_iconv) iconv_close(cd);
+#endif
/* If an equals was pending at end of string, add it now. */
if (equals_pending)
- *q++ = '=';
+ ADDCHR('=');
*q = '\0';
return encoding_found;
+
+ buffull:
+ /* q is currently just off the end of the buffer, so rewind to NUL terminate */
+ q--;
+ *q = '\0';
+ return encoding_found;
}
projects / nmh / blobdiff