145 lines
3.8 KiB
C
145 lines
3.8 KiB
C
/*
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* attach.c - Core mechanix behind attachment replacing
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* I know how mechanics is spelt, let me have my fun :D
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* The author licenses this file
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* to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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*/
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#include "attach.h"
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#include "detect.h"
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#include "config.h"
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#include "mail.h"
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#include "tools.h"
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#include <string.h>
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#include <stdio.h>
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#include <stdbool.h>
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#include <ctype.h>
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#include <stdlib.h>
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struct email_t mail_from_text(char* message, size_t length){
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struct email_t mail;
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memset(&mail, 0, sizeof(mail));
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mail.message = message;
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mail.message_length = length;
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mail.submes_cnt = 0;
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mail.submes = NULL;
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redetect_body_head(&mail);
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char* cont_type = search_header_key(&mail, "Content-Type");
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if(cont_type == NULL){
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/* Halleluja, I've got nothing to do! WOO */
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mail.is_multipart = false;
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return mail;
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}else{
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size_t value_length = 0;
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char * mime_type = get_value_from_key(&value_length,
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cont_type - mail.message, &mail);
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if(mime_type != NULL){
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if(strncasecmp(mime_type, MULTIPART_MIME,
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strlen(MULTIPART_MIME)) == 0){
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/* We have multiple messages cramped inside this
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* one. Let's unravel em!
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*/
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size_t bd_len = 0;
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char* bd = get_multipart_boundary(
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mime_type, value_length, &bd_len);
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if(bd != NULL){
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printf("Received boundary: [%.*s]\n",
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(int)bd_len, bd);
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}
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unravel_multipart_mail(&mail, bd, bd_len);
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}
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}
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}
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return mail;
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}
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void redetect_body_head(struct email_t* mail){
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char* last_lf = NULL;
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char* body_start = NULL;
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bool found_alnum = false;
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for(size_t i = 0; i < mail->message_length; i++){
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if(mail->message[i] == '\n' && !found_alnum){
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body_start = &(mail->message[i+1]);
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break;
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}else if(mail->message[i] == '\n'){
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last_lf = &(mail->message[i]);
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found_alnum = false;
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}else if(isalnum(mail->message[i])){
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found_alnum = true;
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}
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}
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/* In that case we only have a body and no header, or something along
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* those lines... In any case, if postfix delivers that to us, something
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* is probably wrong!
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*/
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if(body_start == NULL) {
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fprintf(stderr, "Received message without header!\n");
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mail->header_len = 0;
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mail->body_offset = 0;
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return;
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}
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mail->body_offset = body_start - mail->message;
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mail->header_len = last_lf - mail->message - 1 /* for the CR */;
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return;
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}
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void unravel_multipart_mail(struct email_t* mail, char* boundary,
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size_t boundary_len){
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return;
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}
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/* Message is required to be a null terminated string, length is the mail body.
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* One may leave something behind the body. len is without the '\0'
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* Attempts to replace files inside the email with links to it on a webserver
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*/
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char* attach_files(char* message, size_t len){
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struct email_t email = mail_from_text(message,len);
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/* Check if mails are signed/encrypted, and abort if nescessary */
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if(abort_on_pgp && detect_pgp(&email)){
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printf("PGP detected, aborting...");
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return email.message;
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}
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/* Check if mails are signed/encrypted, and abort if nescessary */
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if(abort_on_dkim && detect_dkim(&email)){
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printf("DKIM signature detected, aborting...");
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return email.message;
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}
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/* Now we can start the real work! */
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/* Announce our presence via header */
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if(append_header(&email,"X-Mailattached", instance_id) < 0){
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fprintf(stderr, "Failed to attach header!\n");
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return email.message;
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}
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return email.message;
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}
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