--- /dev/null
+/*
+ * $Id$
+ *
+ * This is the MIME parser for Citadel.
+ *
+ * Copyright (c) 1998-2007 by Art Cancro
+ * This code is distributed under the GNU General Public License v3.
+ *
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <ctype.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+#include "libcitadel.h"
+
+
+void extract_key(char *target, char *source, char *key)
+{
+ char *ptr;
+ char looking_for[256];
+ int double_quotes = 0;
+
+ snprintf(looking_for, sizeof looking_for, "%s=", key);
+
+ ptr = bmstrcasestr(source, looking_for);
+ if (ptr == NULL) {
+ strcpy(target, "");
+ return;
+ }
+ strcpy(target, (ptr + strlen(looking_for)));
+
+ for (ptr=target; (*ptr != 0); ++ptr) {
+
+ /* A semicolon means we've hit the end of the key, unless we're inside double quotes */
+ if ( (double_quotes != 1) && (*ptr == ';')) {
+ *ptr = 0;
+ }
+
+ /* if we find double quotes, we've got a great set of string boundaries */
+ if (*ptr == '\"') {
+ ++double_quotes;
+ if (double_quotes == 1) {
+ strcpy(ptr, ptr+1);
+ }
+ else {
+ *ptr = 0;
+ }
+ }
+ }
+}
+
+
+/*
+ * For non-multipart messages, we need to generate a quickie partnum of "1"
+ * to return to callback functions. Some callbacks demand it.
+ */
+char *fixed_partnum(char *supplied_partnum) {
+ if (supplied_partnum == NULL) return "1";
+ if (strlen(supplied_partnum)==0) return "1";
+ return supplied_partnum;
+}
+
+
+
+/*
+ * Convert "quoted-printable" to binary. Returns number of bytes decoded.
+ * according to RFC2045 section 6.7
+ */
+int CtdlDecodeQuotedPrintable(char *decoded, char *encoded, int sourcelen) {
+ unsigned int ch;
+ int decoded_length = 0;
+ int pos = 0;
+
+ while (pos < sourcelen)
+ {
+ if (!strncmp(&encoded[pos], "=\r\n", 3))
+ {
+ pos += 3;
+ }
+ else if (!strncmp(&encoded[pos], "=\n", 2))
+ {
+ pos += 2;
+ }
+ else if (encoded[pos] == '=')
+ {
+ ch = 0;
+ sscanf(&encoded[pos+1], "%02x", &ch);
+ pos += 3;
+ decoded[decoded_length++] = ch;
+ }
+ else
+ {
+ decoded[decoded_length++] = encoded[pos];
+ pos += 1;
+ }
+ }
+ decoded[decoded_length] = 0;
+ return(decoded_length);
+}
+
+
+/*
+ * Given a message or message-part body and a length, handle any necessary
+ * decoding and pass the request up the stack.
+ */
+void mime_decode(char *partnum,
+ char *part_start, size_t length,
+ char *content_type, char *charset, char *encoding,
+ char *disposition,
+ char *name, char *filename,
+ void (*CallBack)
+ (char *cbname,
+ char *cbfilename,
+ char *cbpartnum,
+ char *cbdisp,
+ void *cbcontent,
+ char *cbtype,
+ char *cbcharset,
+ size_t cblength,
+ char *cbencoding,
+ void *cbuserdata),
+ void (*PreMultiPartCallBack)
+ (char *cbname,
+ char *cbfilename,
+ char *cbpartnum,
+ char *cbdisp,
+ void *cbcontent,
+ char *cbtype,
+ char *cbcharset,
+ size_t cblength,
+ char *cbencoding,
+ void *cbuserdata),
+ void (*PostMultiPartCallBack)
+ (char *cbname,
+ char *cbfilename,
+ char *cbpartnum,
+ char *cbdisp,
+ void *cbcontent,
+ char *cbtype,
+ char *cbcharset,
+ size_t cblength,
+ char *cbencoding,
+ void *cbuserdata),
+ void *userdata,
+ int dont_decode
+)
+{
+
+ char *decoded;
+ size_t bytes_decoded = 0;
+
+ /* Some encodings aren't really encodings */
+ if (!strcasecmp(encoding, "7bit"))
+ strcpy(encoding, "");
+ if (!strcasecmp(encoding, "8bit"))
+ strcpy(encoding, "");
+ if (!strcasecmp(encoding, "binary"))
+ strcpy(encoding, "");
+
+ /* If this part is not encoded, send as-is */
+ if ( (strlen(encoding) == 0) || (dont_decode)) {
+ if (CallBack != NULL) {
+ CallBack(name, filename, fixed_partnum(partnum),
+ disposition, part_start,
+ content_type, charset, length, encoding, userdata);
+ }
+ return;
+ }
+
+ /* Fail silently if we hit an unknown encoding. */
+ if ((strcasecmp(encoding, "base64"))
+ && (strcasecmp(encoding, "quoted-printable"))) {
+ return;
+ }
+
+ /*
+ * Allocate a buffer for the decoded data. The output buffer is slightly
+ * larger than the input buffer; this assumes that the decoded data
+ * will never be significantly larger than the encoded data. This is a
+ * safe assumption with base64, uuencode, and quoted-printable.
+ */
+ decoded = malloc(length + 32768);
+ if (decoded == NULL) {
+ return;
+ }
+
+ if (!strcasecmp(encoding, "base64")) {
+ bytes_decoded = CtdlDecodeBase64(decoded, part_start, length);
+ }
+ else if (!strcasecmp(encoding, "quoted-printable")) {
+ bytes_decoded = CtdlDecodeQuotedPrintable(decoded, part_start, length);
+ }
+
+ if (bytes_decoded > 0) if (CallBack != NULL) {
+ CallBack(name, filename, fixed_partnum(partnum),
+ disposition, decoded,
+ content_type, charset, bytes_decoded, "binary", userdata);
+ }
+
+ free(decoded);
+}
+
+/*
+ * Break out the components of a multipart message
+ * (This function expects to be fed HEADERS + CONTENT)
+ * Note: NULL can be supplied as content_end; in this case, the message is
+ * considered to have ended when the parser encounters a 0x00 byte.
+ */
+void the_mime_parser(char *partnum,
+ char *content_start, char *content_end,
+ void (*CallBack)
+ (char *cbname,
+ char *cbfilename,
+ char *cbpartnum,
+ char *cbdisp,
+ void *cbcontent,
+ char *cbtype,
+ char *cbcharset,
+ size_t cblength,
+ char *cbencoding,
+ void *cbuserdata),
+ void (*PreMultiPartCallBack)
+ (char *cbname,
+ char *cbfilename,
+ char *cbpartnum,
+ char *cbdisp,
+ void *cbcontent,
+ char *cbtype,
+ char *cbcharset,
+ size_t cblength,
+ char *cbencoding,
+ void *cbuserdata),
+ void (*PostMultiPartCallBack)
+ (char *cbname,
+ char *cbfilename,
+ char *cbpartnum,
+ char *cbdisp,
+ void *cbcontent,
+ char *cbtype,
+ char *cbcharset,
+ size_t cblength,
+ char *cbencoding,
+ void *cbuserdata),
+ void *userdata,
+ int dont_decode
+)
+{
+
+ char *ptr;
+ char *srch = NULL;
+ char *part_start, *part_end = NULL;
+ char buf[SIZ];
+ char *header;
+ char *boundary;
+ char *startary;
+ size_t startary_len = 0;
+ char *endary;
+ char *next_boundary;
+ char *content_type;
+ char *charset;
+ size_t content_length;
+ char *encoding;
+ char *disposition;
+ char *name = NULL;
+ char *content_type_name;
+ char *content_disposition_name;
+ char *filename;
+ int is_multipart;
+ int part_seq = 0;
+ int i;
+ size_t length;
+ char nested_partnum[256];
+ int crlf_in_use = 0;
+ char *evaluate_crlf_ptr = NULL;
+ int buflen = 0;
+ int headerlen = 0;
+
+ ptr = content_start;
+ content_length = 0;
+
+ boundary = malloc(SIZ);
+ memset(boundary, 0, SIZ);
+
+ startary = malloc(SIZ);
+ memset(startary, 0, SIZ);
+
+ endary = malloc(SIZ);
+ memset(endary, 0, SIZ);
+
+ header = malloc(SIZ);
+ memset(header, 0, SIZ);
+
+ content_type = malloc(SIZ);
+ memset(content_type, 0, SIZ);
+
+ charset = malloc(SIZ);
+ memset(charset, 0, SIZ);
+
+ encoding = malloc(SIZ);
+ memset(encoding, 0, SIZ);
+
+ content_type_name = malloc(SIZ);
+ memset(content_type_name, 0, SIZ);
+
+ content_disposition_name = malloc(SIZ);
+ memset(content_disposition_name, 0, SIZ);
+
+ filename = malloc(SIZ);
+ memset(filename, 0, SIZ);
+
+ disposition = malloc(SIZ);
+ memset(disposition, 0, SIZ);
+
+ /* If the caller didn't supply an endpointer, generate one by measure */
+ if (content_end == NULL) {
+ content_end = &content_start[strlen(content_start)];
+ }
+
+ /* Learn interesting things from the headers */
+ strcpy(header, "");
+ headerlen = 0;
+ do {
+ ptr = memreadlinelen(ptr, buf, SIZ, &buflen);
+ if (ptr >= content_end) {
+ goto end_parser;
+ }
+
+ for (i = 0; i < buflen; ++i) {
+ if (isspace(buf[i])) {
+ buf[i] = ' ';
+ }
+ }
+
+ if (!isspace(buf[0])) {
+ if (!strncasecmp(header, "Content-type:", 13)) {
+ strcpy(content_type, &header[13]);
+ striplt(content_type);
+ extract_key(content_type_name, content_type, "name");
+ extract_key(charset, content_type, "charset");
+ extract_key(boundary, header, "boundary");
+ /* Deal with weird headers */
+ if (strchr(content_type, ' '))
+ *(strchr(content_type, ' ')) = '\0';
+ if (strchr(content_type, ';'))
+ *(strchr(content_type, ';')) = '\0';
+ }
+ if (!strncasecmp(header, "Content-Disposition:", 20)) {
+ strcpy(disposition, &header[20]);
+ striplt(disposition);
+ extract_key(content_disposition_name, disposition, "name");
+ extract_key(filename, disposition, "filename");
+ }
+ if (!strncasecmp(header, "Content-length: ", 15)) {
+ char clbuf[10];
+ safestrncpy(clbuf, &header[15], sizeof clbuf);
+ striplt(clbuf);
+ content_length = (size_t) atol(clbuf);
+ }
+ if (!strncasecmp(header, "Content-transfer-encoding: ", 26)) {
+ strcpy(encoding, &header[26]);
+ striplt(encoding);
+ }
+ strcpy(header, "");
+ headerlen = 0;
+ }
+ if ((headerlen + buflen + 2) < SIZ) {
+ memcpy(&header[headerlen], buf, buflen);
+ headerlen += buflen;
+ header[headerlen] = '\0';
+ }
+ } while ((!IsEmptyStr(buf)) && (*ptr != 0));
+
+ if (strchr(disposition, ';'))
+ *(strchr(disposition, ';')) = '\0';
+ striplt(disposition);
+ if (strchr(content_type, ';'))
+ *(strchr(content_type, ';')) = '\0';
+ striplt(content_type);
+
+ if (!IsEmptyStr(boundary)) {
+ is_multipart = 1;
+ } else {
+ is_multipart = 0;
+ }
+
+ /* If this is a multipart message, then recursively process it */
+ part_start = NULL;
+ if (is_multipart) {
+
+ /* Tell the client about this message's multipartedness */
+ if (PreMultiPartCallBack != NULL) {
+ PreMultiPartCallBack("", "", partnum, "",
+ NULL, content_type, charset,
+ 0, encoding, userdata);
+ }
+
+ /* Figure out where the boundaries are */
+ snprintf(startary, SIZ, "--%s", boundary);
+ snprintf(endary, SIZ, "--%s--", boundary);
+ startary_len = strlen(startary);
+
+ part_start = NULL;
+ do {
+ next_boundary = NULL;
+ for (srch=ptr; srch<content_end; ++srch) {
+ if (!memcmp(srch, startary, startary_len)) {
+ next_boundary = srch;
+ srch = content_end;
+ }
+ }
+
+ if ( (part_start != NULL) && (next_boundary != NULL) ) {
+ part_end = next_boundary;
+ --part_end; /* omit the trailing LF */
+ if (crlf_in_use) {
+ --part_end; /* omit the trailing CR */
+ }
+
+ if (!IsEmptyStr(partnum)) {
+ snprintf(nested_partnum,
+ sizeof nested_partnum,
+ "%s.%d", partnum,
+ ++part_seq);
+ }
+ else {
+ snprintf(nested_partnum,
+ sizeof nested_partnum,
+ "%d", ++part_seq);
+ }
+ the_mime_parser(nested_partnum,
+ part_start, part_end,
+ CallBack,
+ PreMultiPartCallBack,
+ PostMultiPartCallBack,
+ userdata,
+ dont_decode);
+ }
+
+ if (next_boundary != NULL) {
+ /* If we pass out of scope, don't attempt to
+ * read past the end boundary. */
+ if (!strcmp(next_boundary, endary)) {
+ ptr = content_end;
+ }
+ else {
+ /* Set up for the next part. */
+ part_start = strstr(next_boundary, "\n");
+
+ /* Determine whether newlines are LF or CRLF */
+ evaluate_crlf_ptr = part_start;
+ --evaluate_crlf_ptr;
+ if (!memcmp(evaluate_crlf_ptr, "\r\n", 2)) {
+ crlf_in_use = 1;
+ }
+ else {
+ crlf_in_use = 0;
+ }
+
+ /* Advance past the LF ... now we're in the next part */
+ ++part_start;
+ ptr = part_start;
+ }
+ }
+ else {
+ /* Invalid end of multipart. Bail out! */
+ ptr = content_end;
+ }
+ } while ( (ptr < content_end) && (next_boundary != NULL) );
+
+ if (PostMultiPartCallBack != NULL) {
+ PostMultiPartCallBack("", "", partnum, "", NULL,
+ content_type, charset, 0, encoding, userdata);
+ }
+ goto end_parser;
+ }
+
+ /* If it's not a multipart message, then do something with it */
+ if (!is_multipart) {
+ part_start = ptr;
+ length = 0;
+ while (ptr < content_end) {
+ ++ptr;
+ ++length;
+ }
+ part_end = content_end;
+
+ /******
+ * I thought there was an off-by-one error here, but there isn't.
+ * This probably means that there's an off-by-one error somewhere
+ * else ... or maybe only in certain messages?
+ --part_end;
+ --length;
+ ******/
+
+ /* Truncate if the header told us to */
+ if ( (content_length > 0) && (length > content_length) ) {
+ length = content_length;
+ }
+
+ /* Sometimes the "name" field is tacked on to Content-type,
+ * and sometimes it's tacked on to Content-disposition. Use
+ * whichever one we have.
+ */
+ if (strlen(content_disposition_name) > strlen(content_type_name)) {
+ name = content_disposition_name;
+ }
+ else {
+ name = content_type_name;
+ }
+
+ /* Ok, we've got a non-multipart part here, so do something with it.
+ */
+ mime_decode(partnum,
+ part_start, length,
+ content_type, charset, encoding, disposition,
+ name, filename,
+ CallBack, NULL, NULL,
+ userdata, dont_decode
+ );
+
+ /*
+ * Now if it's an encapsulated message/rfc822 then we have to recurse into it
+ */
+ if (!strcasecmp(content_type, "message/rfc822")) {
+
+ if (PreMultiPartCallBack != NULL) {
+ PreMultiPartCallBack("", "", partnum, "",
+ NULL, content_type, charset,
+ 0, encoding, userdata);
+ }
+ if (CallBack != NULL) {
+ if (strlen(partnum) > 0) {
+ snprintf(nested_partnum,
+ sizeof nested_partnum,
+ "%s.%d", partnum,
+ ++part_seq);
+ }
+ else {
+ snprintf(nested_partnum,
+ sizeof nested_partnum,
+ "%d", ++part_seq);
+ }
+ the_mime_parser(nested_partnum,
+ part_start, part_end,
+ CallBack,
+ PreMultiPartCallBack,
+ PostMultiPartCallBack,
+ userdata,
+ dont_decode
+ );
+ }
+ if (PostMultiPartCallBack != NULL) {
+ PostMultiPartCallBack("", "", partnum, "", NULL,
+ content_type, charset, 0, encoding, userdata);
+ }
+
+
+ }
+
+ }
+
+end_parser: /* free the buffers! end the oppression!! */
+ free(boundary);
+ free(startary);
+ free(endary);
+ free(header);
+ free(content_type);
+ free(charset);
+ free(encoding);
+ free(content_type_name);
+ free(content_disposition_name);
+ free(filename);
+ free(disposition);
+}
+
+
+
+/*
+ * Entry point for the MIME parser.
+ * (This function expects to be fed HEADERS + CONTENT)
+ * Note: NULL can be supplied as content_end; in this case, the message is
+ * considered to have ended when the parser encounters a 0x00 byte.
+ */
+void mime_parser(char *content_start,
+ char *content_end,
+
+ void (*CallBack)
+ (char *cbname,
+ char *cbfilename,
+ char *cbpartnum,
+ char *cbdisp,
+ void *cbcontent,
+ char *cbtype,
+ char *cbcharset,
+ size_t cblength,
+ char *cbencoding,
+ void *cbuserdata),
+
+ void (*PreMultiPartCallBack)
+ (char *cbname,
+ char *cbfilename,
+ char *cbpartnum,
+ char *cbdisp,
+ void *cbcontent,
+ char *cbtype,
+ char *cbcharset,
+ size_t cblength,
+ char *cbencoding,
+ void *cbuserdata),
+
+ void (*PostMultiPartCallBack)
+ (char *cbname,
+ char *cbfilename,
+ char *cbpartnum,
+ char *cbdisp,
+ void *cbcontent,
+ char *cbtype,
+ char *cbcharset,
+ size_t cblength,
+ char *cbencoding,
+ void *cbuserdata),
+
+ void *userdata,
+ int dont_decode
+)
+{
+
+ the_mime_parser("", content_start, content_end,
+ CallBack,
+ PreMultiPartCallBack,
+ PostMultiPartCallBack,
+ userdata, dont_decode);
+}
projects / citadel.git / commitdiff