+++ /dev/null
-//
-// Output an HTML message, modifying it slightly to make sure it plays nice
-// with the rest of our web framework.
-//
-// Copyright (c) 2005-2020 by the citadel.org team
-//
-// This program is open source software. It runs great on the
-// Linux operating system (and probably elsewhere). You can use,
-// copy, and run it under the terms of the GNU General Public
-// License version 3.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU General Public License for more details.
-
-#include "webcit.h"
-
-
-// Strip surrounding single or double quotes from a string.
-void stripquotes(char *s) {
- int len;
-
- if (!s)
- return;
-
- len = strlen(s);
- if (len < 2)
- return;
-
- if (((s[0] == '\"') && (s[len - 1] == '\"')) || ((s[0] == '\'') && (s[len - 1] == '\''))) {
- s[len - 1] = 0;
- strcpy(s, &s[1]);
- }
-}
-
-
-// Check to see if a META tag has overridden the declared MIME character set.
-//
-// charset Character set name (left unchanged if we don't do anything)
-// meta_http_equiv Content of the "http-equiv" portion of the META tag
-// meta_content Content of the "content" portion of the META tag
-void extract_charset_from_meta(char *charset, char *meta_http_equiv, char *meta_content) {
- char *ptr;
- char buf[64];
-
- if (!charset)
- return;
- if (!meta_http_equiv)
- return;
- if (!meta_content)
- return;
-
- if (strcasecmp(meta_http_equiv, "Content-type"))
- return;
-
- ptr = strchr(meta_content, ';');
- if (!ptr)
- return;
-
- safestrncpy(buf, ++ptr, sizeof buf);
- striplt(buf);
- if (!strncasecmp(buf, "charset=", 8)) {
- strcpy(charset, &buf[8]);
-
- // The brain-damaged webmail program in Microsoft Exchange declares
- // a charset of "unicode" when they really mean "UTF-8". GNU iconv
- // treats "unicode" as an alias for "UTF-16" so we have to manually
- // fix this here, otherwise messages generated in Exchange webmail
- // show up as a big pile of weird characters.
- if (!strcasecmp(charset, "unicode")) {
- strcpy(charset, "UTF-8");
- }
-
- // Remove wandering punctuation
- if ((ptr = strchr(charset, '\"')))
- *ptr = 0;
- striplt(charset);
- }
-}
-
-
-// Sanitize and enhance an HTML message for display.
-// Also convert weird character sets to UTF-8 if necessary.
-// Also fixup img src="cid:..." type inline images to fetch the image
-StrBuf *html2html(const char *supplied_charset, int treat_as_wiki, char *roomname, long msgnum, StrBuf *Source) {
- char buf[SIZ];
- char *msg;
- char *ptr;
- char *msgstart;
- char *msgend;
- StrBuf *converted_msg;
- int buffer_length = 1;
- int line_length = 0;
- int content_length = 0;
- char new_window[SIZ];
- int brak = 0;
- int alevel = 0;
- int scriptlevel = 0;
- int script_start_pos = (-1);
- int i;
- int linklen;
- char charset[128];
- StrBuf *BodyArea = NULL;
-
- 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 *osav; // Saved pointer to output buffer
-
- StrBuf *Target = NewStrBuf();
- if (Target == NULL) {
- return (NULL);
- }
-
- safestrncpy(charset, supplied_charset, sizeof charset);
- sprintf(new_window, "<a target=\"%s\" href=", TARGET);
-
- content_length = StrLength(Source);
- msg = (char *) ChrPtr(Source);
- buffer_length = content_length;
-
- // Do a first pass to isolate the message body
- ptr = msg + 1;
- msgstart = msg;
- msgend = &msg[content_length];
-
- while (ptr < msgend) {
-
- // Advance to next tag
- ptr = strchr(ptr, '<');
- if ((ptr == NULL) || (ptr >= msgend))
- break;
- ++ptr;
- if ((ptr == NULL) || (ptr >= msgend))
- break;
-
- // Look for META tags. Some messages (particularly in
- // Asian locales) illegally declare a message's character
- // set in the HTML instead of in the MIME headers. This
- // is wrong but we have to work around it anyway.
- if (!strncasecmp(ptr, "META", 4)) {
-
- char *meta_start;
- char *meta_end;
- int meta_length;
- char *meta;
- char *meta_http_equiv;
- char *meta_content;
- char *spaceptr;
-
- meta_start = &ptr[4];
- meta_end = strchr(ptr, '>');
- if ((meta_end != NULL) && (meta_end <= msgend)) {
- meta_length = meta_end - meta_start + 1;
- meta = malloc(meta_length + 1);
- safestrncpy(meta, meta_start, meta_length);
- meta[meta_length] = 0;
- striplt(meta);
- if (!strncasecmp(meta, "HTTP-EQUIV=", 11)) {
- meta_http_equiv = strdup(&meta[11]);
- spaceptr = strchr(meta_http_equiv, ' ');
- if (spaceptr != NULL) {
- *spaceptr = 0;
- meta_content = strdup(++spaceptr);
- if (!strncasecmp(meta_content, "content=", 8)) {
- strcpy(meta_content, &meta_content[8]);
- stripquotes(meta_http_equiv);
- stripquotes(meta_content);
- extract_charset_from_meta(charset, meta_http_equiv, meta_content);
- }
- free(meta_content);
- }
- free(meta_http_equiv);
- }
- free(meta);
- }
- }
-
- // Any of these tags cause everything up to and including
- // the tag to be removed.
- if ((!strncasecmp(ptr, "HTML", 4))
- || (!strncasecmp(ptr, "HEAD", 4))
- || (!strncasecmp(ptr, "/HEAD", 5))
- || (!strncasecmp(ptr, "BODY", 4))) {
- char *pBody = NULL;
-
- if (!strncasecmp(ptr, "BODY", 4)) {
- pBody = ptr;
- }
- ptr = strchr(ptr, '>');
- if ((ptr == NULL) || (ptr >= msgend))
- break;
- if ((pBody != NULL) && (ptr - pBody > 4)) {
- char *src;
- char *cid_start, *cid_end;
-
- *ptr = '\0';
- pBody += 4;
- while ((isspace(*pBody)) && (pBody < ptr))
- pBody++;
- BodyArea = NewStrBufPlain(NULL, ptr - pBody);
-
- if (pBody < ptr) {
- src = strstr(pBody, "cid:");
- if (src) {
- cid_start = src + 4;
- cid_end = cid_start;
- while ((*cid_end != '"') && !isspace(*cid_end) && (cid_end < ptr))
- cid_end++;
-
- // copy tag and attributes up to src="cid:
- StrBufAppendBufPlain(BodyArea, pBody, src - pBody, 0);
-
- // add in /webcit/mimepart/<msgno>/CID/
- // trailing / stops dumb URL filters getting excited
- StrBufAppendPrintf(BodyArea, "/webcit/mimepart/%ld/", msgnum);
- StrBufAppendBufPlain(BodyArea, cid_start, cid_end - cid_start, 0);
-
- if (ptr - cid_end > 0)
- StrBufAppendBufPlain(BodyArea, cid_end + 1, ptr - cid_end, 0);
- } else
- StrBufAppendBufPlain(BodyArea, pBody, ptr - pBody, 0);
- }
- *ptr = '>';
- }
- ++ptr;
- if ((ptr == NULL) || (ptr >= msgend))
- break;
- msgstart = ptr;
- }
-
- // Any of these tags cause everything including and following
- // the tag to be removed.
- if ((!strncasecmp(ptr, "/HTML", 5)) || (!strncasecmp(ptr, "/BODY", 5))) {
- --ptr;
- msgend = ptr;
- strcpy(ptr, "");
- }
-
- ++ptr;
- }
- if (msgstart > msg) {
- strcpy(msg, msgstart);
- }
-
- // Now go through the message, parsing tags as necessary.
- converted_msg = NewStrBufPlain(NULL, content_length + 8192);
-
- // Convert foreign character sets to UTF-8 if necessary
- if ((strcasecmp(charset, "us-ascii"))
- && (strcasecmp(charset, "UTF-8"))
- && (strcasecmp(charset, ""))
- ) {
- syslog(LOG_DEBUG, "Converting %s to UTF-8", charset);
- ctdl_iconv_open("UTF-8", charset, &ic);
- if (ic == (iconv_t) (-1)) {
- syslog(LOG_WARNING, "%s:%d iconv_open() failed: %s", __FILE__, __LINE__, strerror(errno));
- }
- }
- if (Source == NULL) {
- if (ic != (iconv_t) (-1)) {
- ibuf = msg;
- ibuflen = content_length;
- obuflen = content_length + (content_length / 2);
- obuf = (char *) malloc(obuflen);
- osav = obuf;
- iconv(ic, &ibuf, &ibuflen, &obuf, &obuflen);
- content_length = content_length + (content_length / 2) - obuflen;
- osav[content_length] = 0;
- free(msg);
- msg = osav;
- iconv_close(ic);
- }
- } else {
- if (ic != (iconv_t) (-1)) {
- StrBuf *Buf = NewStrBufPlain(NULL, StrLength(Source) + 8096);;
- StrBufConvert(Source, Buf, &ic);
- FreeStrBuf(&Buf);
- iconv_close(ic);
- msg = (char *) ChrPtr(Source); // TODO: get rid of this.
- }
- }
-
- // At this point, the message has been stripped down to
- // only the content inside the <BODY></BODY> tags, and has
- // been converted to UTF-8 if it was originally in a foreign
- // character set. The text is also guaranteed to be null
- // terminated now.
-
- if (converted_msg == NULL) {
- StrBufAppendPrintf(Target, "Error %d: %s<br>%s:%d", errno, strerror(errno), __FILE__, __LINE__);
- goto BAIL;
- }
-
- if (BodyArea != NULL) { // Any attributes that were declared in the <body> tag
- StrBufAppendBufPlain(converted_msg, HKEY("<div "), 0); // are instead declared in this <div> tag
- StrBufAppendBuf(converted_msg, BodyArea, 0);
- StrBufAppendBufPlain(converted_msg, HKEY(">"), 0);
- }
- ptr = msg;
- msgend = strchr(msg, 0);
- while (ptr < msgend) {
-
- // Try to sanitize the html of any rogue scripts
- if (!strncasecmp(ptr, "<script", 7)) {
- if (scriptlevel == 0) {
- script_start_pos = StrLength(converted_msg);
- }
- ++scriptlevel;
- }
- if (!strncasecmp(ptr, "</script", 8)) {
- --scriptlevel;
- }
-
- // Change mailto: links to WebCit mail, by replacing the
- // link with one that points back to our mail room. Due to
- // the way we parse URL's, it'll even handle mailto: links
- // that have "?subject=" in them.
- // FIXME change URL syntax for webcit-ng
- if (!strncasecmp(ptr, "<a href=\"mailto:", 16)) {
- content_length += 64;
- StrBufAppendPrintf(converted_msg, "<a href=\"display_enter?force_room=_MAIL_?recp=");
- ptr = &ptr[16];
- ++alevel;
- ++brak;
- }
-
- // Make external links open in a separate window
- else if (!strncasecmp(ptr, "<a href=\"", 9)) {
- ++alevel;
- ++brak;
- if (((strchr(ptr, ':') < strchr(ptr, '/'))) && ((strchr(ptr, '/') < strchr(ptr, '>')))) {
- // open external links to new window
- StrBufAppendPrintf(converted_msg, new_window);
- ptr = &ptr[8];
- } else if ((treat_as_wiki)
- && (strncasecmp(ptr, "<a href=\"wiki?", 14))
- && (strncasecmp(ptr, "<a href=\"dotgoto?", 17))
- && (strncasecmp(ptr, "<a href=\"knrooms?", 17))
- ) {
- content_length += 64;
- StrBufAppendPrintf(converted_msg, "<a href=\"wiki?go=");
- //StrBufUrlescAppend(converted_msg, "FIXME ROOM NAME", NULL); // FIXME make compatible with webcit-ng
- StrBufAppendPrintf(converted_msg, "?page=");
- ptr = &ptr[9];
- } else {
- StrBufAppendPrintf(converted_msg, "<a href=\"");
- ptr = &ptr[9];
- }
- }
-
- // Fixup <img src="cid:... ...> to fetch the mime part
- else if (!strncasecmp(ptr, "<img ", 5)) {
- char *cid_start, *cid_end;
- char *tag_end = strchr(ptr, '>');
- char *src;
- // FIXME - handle this situation (maybe someone opened an <img cid...
- // and then ended the message)
- if (!tag_end) {
- syslog(LOG_DEBUG, "tag_end is null and ptr is:");
- syslog(LOG_DEBUG, "%s", ptr);
- syslog(LOG_DEBUG, "Theoretical bytes remaining: %d", (int) (msgend - ptr));
- }
-
- src = strstr(ptr, "src=\"cid:");
- ++brak;
-
- if (src && isspace(*(src - 1))
- && tag_end && (cid_start = strchr(src, ':'))
- && (cid_end = strchr(cid_start, '"'))
- && (cid_end < tag_end)
- ) {
- // copy tag and attributes up to src="cid:
- StrBufAppendBufPlain(converted_msg, ptr, src - ptr, 0);
- cid_start++;
-
- // add in /webcit/mimepart/<msgnum>/CID/
- // trailing / stops dumb URL filters getting excited
- StrBufAppendPrintf(converted_msg, " src=\"/ctdl/r/");
- StrBufXMLEscAppend(converted_msg, NULL, roomname, strlen(roomname), 0);
- syslog(LOG_DEBUG, "room name is '%s'", roomname);
- StrBufAppendPrintf(converted_msg, "/%ld/", msgnum);
- StrBufAppendBufPlain(converted_msg, cid_start, cid_end - cid_start, 0);
- StrBufAppendBufPlain(converted_msg, "\"", -1, 0);
- ptr = cid_end + 1;
- }
- StrBufAppendBufPlain(converted_msg, ptr, tag_end - ptr, 0);
- ptr = tag_end;
- }
-
- // Turn anything that looks like a URL into a real link, as long
- // as it's not inside a tag already
- else if ((brak == 0) && (alevel == 0) && ((!strncasecmp(ptr, "http://", 7)) || (!strncasecmp(ptr, "https://", 8)))) {
- // Find the end of the link
- int strlenptr;
- linklen = 0;
-
- strlenptr = strlen(ptr);
- for (i = 0; i <= strlenptr; ++i) {
- if ((ptr[i] == 0)
- || (isspace(ptr[i]))
- || (ptr[i] == 10)
- || (ptr[i] == 13)
- || (ptr[i] == '(')
- || (ptr[i] == ')')
- || (ptr[i] == '<')
- || (ptr[i] == '>')
- || (ptr[i] == '[')
- || (ptr[i] == ']')
- || (ptr[i] == '"')
- || (ptr[i] == '\'')
- )
- linklen = i;
- // entity tag?
- if (ptr[i] == '&') {
- if ((ptr[i + 2] == ';') ||
- (ptr[i + 3] == ';') ||
- (ptr[i + 5] == ';') || (ptr[i + 6] == ';') || (ptr[i + 7] == ';'))
- linklen = i;
- }
- if (linklen > 0)
- break;
- }
- if (linklen > 0) {
- char *ltreviewptr;
- char *nbspreviewptr;
- char linkedchar;
- int len;
-
- len = linklen;
- linkedchar = ptr[len];
- ptr[len] = '\0';
- // spot for some subject strings tinymce tends to give us.
- ltreviewptr = strchr(ptr, '<');
- if (ltreviewptr != NULL) {
- *ltreviewptr = '\0';
- linklen = ltreviewptr - ptr;
- }
-
- nbspreviewptr = strstr(ptr, " ");
- if (nbspreviewptr != NULL) {
- // nbspreviewptr = '\0';
- linklen = nbspreviewptr - ptr;
- }
- if (ltreviewptr != 0)
- *ltreviewptr = '<';
-
- ptr[len] = linkedchar;
-
- content_length += (32 + linklen);
- StrBufAppendPrintf(converted_msg, "%s\"", new_window);
- StrBufAppendBufPlain(converted_msg, ptr, linklen, 0);
- StrBufAppendPrintf(converted_msg, "\">");
- StrBufAppendBufPlain(converted_msg, ptr, linklen, 0);
- ptr += linklen;
- StrBufAppendPrintf(converted_msg, "</a>");
- }
- }
- else {
- StrBufAppendBufPlain(converted_msg, ptr, 1, 0);
- ptr++;
- }
-
- if ((ptr >= msg) && (ptr <= msgend)) {
- // We need to know when we're inside a tag,
- // so we don't turn things that look like URL's into
- // links, when they're already links - or image sources.
- if ((ptr > msg) && (*(ptr - 1) == '<')) {
- ++brak;
- }
- if ((ptr > msg) && (*(ptr - 1) == '>')) {
- --brak;
- if ((scriptlevel == 0) && (script_start_pos >= 0)) {
- StrBufCutRight(converted_msg, StrLength(converted_msg) - script_start_pos);
- script_start_pos = (-1);
- }
- }
- if (!strncasecmp(ptr, "</a>", 3))
- --alevel;
- }
- }
-
- if (BodyArea != NULL) {
- StrBufAppendBufPlain(converted_msg, HKEY("</div>"), 0); // Close the div where we declared attributes copied
- FreeStrBuf(&BodyArea); // from the original <body> tag
- }
-
- // uncomment these two lines to override conversion
- // memcpy(converted_msg, msg, content_length);
- // output_length = content_length;
-
- /* Output our big pile of markup */
- StrBufAppendBuf(Target, converted_msg, 0);
-
- BAIL: // A little trailing vertical whitespace...
- StrBufAppendPrintf(Target, "<br>\n");
-
- // Now give back the memory
- FreeStrBuf(&converted_msg);
- if ((msg != NULL) && (Source == NULL))
- free(msg);
- return (Target);
-}
-
-
-// Look for URL's embedded in a buffer and make them linkable. We use a
-// target window in order to keep the Citadel session in its own window.
-void UrlizeText(StrBuf * Target, StrBuf * Source, StrBuf * WrkBuf) {
- int len, UrlLen, Offset, TrailerLen;
- const char *start, *end, *pos;
-
- FlushStrBuf(Target);
- start = NULL;
- len = StrLength(Source);
- end = ChrPtr(Source) + len;
- for (pos = ChrPtr(Source); (pos < end) && (start == NULL); ++pos) {
- if (!strncasecmp(pos, "http://", 7))
- start = pos;
- else if (!strncasecmp(pos, "ftp://", 6))
- start = pos;
- }
-
- if (start == NULL) {
- StrBufAppendBuf(Target, Source, 0);
- return;
- }
- FlushStrBuf(WrkBuf);
-
- for (pos = ChrPtr(Source) + len; pos > start; --pos) {
- if ((!isprint(*pos))
- || (isspace(*pos))
- || (*pos == '{')
- || (*pos == '}')
- || (*pos == '|')
- || (*pos == '\\')
- || (*pos == '^')
- || (*pos == '[')
- || (*pos == ']')
- || (*pos == '`')
- || (*pos == '<')
- || (*pos == '>')
- || (*pos == '(')
- || (*pos == ')')
- ) {
- end = pos;
- }
- }
-
- UrlLen = end - start;
- StrBufAppendBufPlain(WrkBuf, start, UrlLen, 0);
-
- Offset = start - ChrPtr(Source);
- if (Offset != 0)
- StrBufAppendBufPlain(Target, ChrPtr(Source), Offset, 0);
- StrBufAppendPrintf(Target, "%ca href=%c%s%c TARGET=%c%s%c%c%s%c/A%c",
- LB, QU, ChrPtr(WrkBuf), QU, QU, TARGET, QU, RB, ChrPtr(WrkBuf), LB, RB);
-
- TrailerLen = StrLength(Source) - (end - ChrPtr(Source));
- if (TrailerLen > 0)
- StrBufAppendBufPlain(Target, end, TrailerLen, 0);
-}
-
-
-void url(char *buf, size_t bufsize) {
- int len, UrlLen, Offset, TrailerLen, outpos;
- char *start, *end, *pos;
- char urlbuf[SIZ];
- char outbuf[SIZ];
-
- start = NULL;
- len = strlen(buf);
- if (len > bufsize) {
- syslog(LOG_WARNING, "URL: content longer than buffer!");
- return;
- }
- end = buf + len;
- for (pos = buf; (pos < end) && (start == NULL); ++pos) {
- if (!strncasecmp(pos, "http://", 7))
- start = pos;
- if (!strncasecmp(pos, "ftp://", 6))
- start = pos;
- }
-
- if (start == NULL)
- return;
-
- for (pos = buf + len; pos > start; --pos) {
- if ((!isprint(*pos))
- || (isspace(*pos))
- || (*pos == '{')
- || (*pos == '}')
- || (*pos == '|')
- || (*pos == '\\')
- || (*pos == '^')
- || (*pos == '[')
- || (*pos == ']')
- || (*pos == '`')
- || (*pos == '<')
- || (*pos == '>')
- || (*pos == '(')
- || (*pos == ')')
- ) {
- end = pos;
- }
- }
-
- UrlLen = end - start;
- if (UrlLen > sizeof(urlbuf)) {
- syslog(LOG_WARNING, "URL: content longer than buffer!");
- return;
- }
- memcpy(urlbuf, start, UrlLen);
- urlbuf[UrlLen] = '\0';
-
- Offset = start - buf;
- if ((Offset != 0) && (Offset < sizeof(outbuf)))
- memcpy(outbuf, buf, Offset);
- outpos = snprintf(&outbuf[Offset], sizeof(outbuf) - Offset,
- "%ca href=%c%s%c TARGET=%c%s%c%c%s%c/A%c", LB, QU, urlbuf, QU, QU, TARGET, QU, RB, urlbuf, LB, RB);
- if (outpos >= sizeof(outbuf) - Offset) {
- syslog(LOG_WARNING, "URL: content longer than buffer!");
- return;
- }
-
- TrailerLen = len - (end - start);
- if (TrailerLen > 0)
- memcpy(outbuf + Offset + outpos, end, TrailerLen);
- if (Offset + outpos + TrailerLen > bufsize) {
- syslog(LOG_WARNING, "URL: content longer than buffer!");
- return;
- }
- memcpy(buf, outbuf, Offset + outpos + TrailerLen);
- *(buf + Offset + outpos + TrailerLen) = '\0';
-}