+#include "ctdl_module.h"
+#ifdef HAVE_ICONV
+#include <iconv.h>
+
+#if 0
+/* This is the non-define version in case it is needed for debugging */
+inline void FindNextEnd (char *bptr, char *end)
+{
+ /* Find the next ?Q? */
+ end = strchr(bptr + 2, '?');
+ if (end == NULL) return NULL;
+ if (((*(end + 1) == 'B') || (*(end + 1) == 'Q')) &&
+ (*(end + 2) == '?')) {
+ /* skip on to the end of the cluster, the next ?= */
+ end = strstr(end + 3, "?=");
+ }
+ else
+ /* sort of half valid encoding, try to find an end. */
+ end = strstr(bptr, "?=");
+}
+#endif
+
+#define FindNextEnd(bptr, end) { \
+ end = strchr(bptr + 2, '?'); \
+ if (end != NULL) { \
+ if (((*(end + 1) == 'B') || (*(end + 1) == 'Q')) && (*(end + 2) == '?')) { \
+ end = strstr(end + 3, "?="); \
+ } else end = strstr(bptr, "?="); \
+ } \
+}
+
+/*
+ * Handle subjects with RFC2047 encoding such as:
+ * =?koi8-r?B?78bP0s3Mxc7JxSDXz9rE1dvO2c3JINvB0sHNySDP?=
+ */
+void utf8ify_rfc822_string(char *buf) {
+ char *start, *end, *next, *nextend, *ptr;
+ char newbuf[1024];
+ char charset[128];
+ char encoding[16];
+ char istr[1024];
+ iconv_t ic = (iconv_t)(-1) ;
+ char *ibuf; // Buffer of characters to be converted
+ char *obuf; // Buffer for converted characters
+ size_t ibuflen; // Length of input buffer
+ size_t obuflen; // Length of output buffer
+ char *isav; // Saved pointer to input buffer
+ char *osav; // Saved pointer to output buffer
+ int passes = 0;
+ int i, len, delta;
+ int illegal_non_rfc2047_encoding = 0;
+
+ /* Sometimes, badly formed messages contain strings which were simply
+ * written out directly in some foreign character set instead of
+ * using RFC2047 encoding. This is illegal but we will attempt to
+ * handle it anyway by converting from a user-specified default
+ * charset to UTF-8 if we see any nonprintable characters.
+ */
+ len = strlen(buf);
+ for (i=0; i<len; ++i) {
+ if ((buf[i] < 32) || (buf[i] > 126)) {
+ illegal_non_rfc2047_encoding = 1;
+ i = len; // take a shortcut, it won't be more than one.
+ }
+ }
+ if (illegal_non_rfc2047_encoding) {
+ const char *default_header_charset = "iso-8859-1";
+ if ( (strcasecmp(default_header_charset, "UTF-8")) && (strcasecmp(default_header_charset, "us-ascii")) ) {
+ ctdl_iconv_open("UTF-8", default_header_charset, &ic);
+ if (ic != (iconv_t)(-1) ) {
+ ibuf = malloc(1024);
+ isav = ibuf;
+ safestrncpy(ibuf, buf, 1024);
+ ibuflen = strlen(ibuf);
+ obuflen = 1024;
+ obuf = (char *) malloc(obuflen);
+ osav = obuf;
+ iconv(ic, &ibuf, &ibuflen, &obuf, &obuflen);
+ osav[1024-obuflen] = 0;
+ strcpy(buf, osav);
+ free(osav);
+ iconv_close(ic);
+ free(isav);
+ }
+ }
+ }
+
+ /* pre evaluate the first pair */
+ nextend = end = NULL;
+ len = strlen(buf);
+ start = strstr(buf, "=?");
+ if (start != NULL)
+ FindNextEnd (start, end);
+
+ while ((start != NULL) && (end != NULL))
+ {
+ next = strstr(end, "=?");
+ if (next != NULL)
+ FindNextEnd(next, nextend);
+ if (nextend == NULL)
+ next = NULL;
+
+ /* did we find two partitions */
+ if ((next != NULL) &&
+ ((next - end) > 2))
+ {
+ ptr = end + 2;
+ while ((ptr < next) &&
+ (isspace(*ptr) ||
+ (*ptr == '\r') ||
+ (*ptr == '\n') ||
+ (*ptr == '\t')))
+ ptr ++;
+ /* did we find a gab just filled with blanks? */
+ if (ptr == next)
+ {
+ memmove (end + 2,
+ next,
+ len - (next - start));
+
+ /* now terminate the gab at the end */
+ delta = (next - end) - 2;
+ len -= delta;
+ buf[len] = '\0';
+
+ /* move next to its new location. */
+ next -= delta;
+ nextend -= delta;
+ }
+ }
+ /* our next-pair is our new first pair now. */
+ start = next;
+ end = nextend;
+ }
+
+ /* Now we handle foreign character sets properly encoded
+ * in RFC2047 format.
+ */
+ start = strstr(buf, "=?");
+ FindNextEnd((start != NULL)? start : buf, end);
+ while (start != NULL && end != NULL && end > start)
+ {
+ extract_token(charset, start, 1, '?', sizeof charset);
+ extract_token(encoding, start, 2, '?', sizeof encoding);
+ extract_token(istr, start, 3, '?', sizeof istr);
+
+ ibuf = malloc(1024);
+ isav = ibuf;
+ if (!strcasecmp(encoding, "B")) { // base64
+ ibuflen = CtdlDecodeBase64(ibuf, istr, strlen(istr));
+ }
+ else if (!strcasecmp(encoding, "Q")) { // quoted-printable
+ size_t len;
+ unsigned long pos;
+
+ len = strlen(istr);
+ pos = 0;
+ while (pos < len)
+ {
+ if (istr[pos] == '_') istr[pos] = ' ';
+ pos++;
+ }
+
+ ibuflen = CtdlDecodeQuotedPrintable(ibuf, istr, len);
+ }
+ else {
+ strcpy(ibuf, istr); // unknown encoding
+ ibuflen = strlen(istr);
+ }
+
+ ctdl_iconv_open("UTF-8", charset, &ic);
+ if (ic != (iconv_t)(-1) ) {
+ obuflen = 1024;
+ obuf = (char *) malloc(obuflen);
+ osav = obuf;
+ iconv(ic, &ibuf, &ibuflen, &obuf, &obuflen);
+ osav[1024-obuflen] = 0;
+
+ end = start;
+ end++;
+ strcpy(start, "");
+ remove_token(end, 0, '?');
+ remove_token(end, 0, '?');
+ remove_token(end, 0, '?');
+ remove_token(end, 0, '?');
+ strcpy(end, &end[1]);
+
+ snprintf(newbuf, sizeof newbuf, "%s%s%s", buf, osav, end);
+ strcpy(buf, newbuf);
+ free(osav);
+ iconv_close(ic);
+ }
+ else {
+ end = start;
+ end++;
+ strcpy(start, "");
+ remove_token(end, 0, '?');
+ remove_token(end, 0, '?');
+ remove_token(end, 0, '?');
+ remove_token(end, 0, '?');
+ strcpy(end, &end[1]);
+
+ snprintf(newbuf, sizeof newbuf, "%s(unreadable)%s", buf, end);
+ strcpy(buf, newbuf);
+ }
+
+ free(isav);