quickjs-tart

quickjs-based runtime for wallet-core logic
Log | Files | Refs | README | LICENSE

smtp-tls.c (6382B)

      1 /***************************************************************************
      2  *                                  _   _ ____  _
      3  *  Project                     ___| | | |  _ \| |
      4  *                             / __| | | | |_) | |
      5  *                            | (__| |_| |  _ <| |___
      6  *                             \___|\___/|_| \_\_____|
      7  *
      8  * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
      9  *
     10  * This software is licensed as described in the file COPYING, which
     11  * you should have received as part of this distribution. The terms
     12  * are also available at https://curl.se/docs/copyright.html.
     13  *
     14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
     15  * copies of the Software, and permit persons to whom the Software is
     16  * furnished to do so, under the terms of the COPYING file.
     17  *
     18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
     19  * KIND, either express or implied.
     20  *
     21  * SPDX-License-Identifier: curl
     22  *
     23  ***************************************************************************/
     24 
     25 /* <DESC>
     26  * Send SMTP email using implicit TLS
     27  * </DESC>
     28  */
     29 
     30 #include <stdio.h>
     31 #include <string.h>
     32 #include <curl/curl.h>
     33 
     34 /* This is a simple example showing how to send mail using libcurl's SMTP
     35  * capabilities. It builds on the smtp-mail.c example to add authentication
     36  * and, more importantly, transport security to protect the authentication
     37  * details from being snooped.
     38  *
     39  * Note that this example requires libcurl 7.20.0 or above.
     40  */
     41 
     42 #define FROM_MAIL     "<sender@example.com>"
     43 #define TO_MAIL       "<recipient@example.com>"
     44 #define CC_MAIL       "<info@example.com>"
     45 
     46 static const char *payload_text =
     47   "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
     48   "To: " TO_MAIL "\r\n"
     49   "From: " FROM_MAIL "\r\n"
     50   "Cc: " CC_MAIL "\r\n"
     51   "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
     52   "rfcpedant.example.org>\r\n"
     53   "Subject: SMTP example message\r\n"
     54   "\r\n" /* empty line to divide headers from body, see RFC 5322 */
     55   "The body of the message starts here.\r\n"
     56   "\r\n"
     57   "It could be a lot of lines, could be MIME encoded, whatever.\r\n"
     58   "Check RFC 5322.\r\n";
     59 
     60 struct upload_status {
     61   size_t bytes_read;
     62 };
     63 
     64 static size_t payload_source(char *ptr, size_t size, size_t nmemb, void *userp)
     65 {
     66   struct upload_status *upload_ctx = (struct upload_status *)userp;
     67   const char *data;
     68   size_t room = size * nmemb;
     69 
     70   if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) {
     71     return 0;
     72   }
     73 
     74   data = &payload_text[upload_ctx->bytes_read];
     75 
     76   if(data) {
     77     size_t len = strlen(data);
     78     if(room < len)
     79       len = room;
     80     memcpy(ptr, data, len);
     81     upload_ctx->bytes_read += len;
     82 
     83     return len;
     84   }
     85 
     86   return 0;
     87 }
     88 
     89 int main(void)
     90 {
     91   CURL *curl;
     92   CURLcode res = CURLE_OK;
     93   struct curl_slist *recipients = NULL;
     94   struct upload_status upload_ctx = { 0 };
     95 
     96   curl = curl_easy_init();
     97   if(curl) {
     98     /* Set username and password */
     99     curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
    100     curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
    101 
    102     /* This is the URL for your mailserver. Note the use of port 587 here,
    103      * instead of the normal SMTP port (25). Port 587 is commonly used for
    104      * secure mail submission (see RFC 4403), but you should use whatever
    105      * matches your server configuration. */
    106     curl_easy_setopt(curl, CURLOPT_URL, "smtp://mainserver.example.net:587");
    107 
    108     /* In this example, we start with a plain text connection, and upgrade to
    109      * Transport Layer Security (TLS) using the STARTTLS command. Be careful
    110      * of using CURLUSESSL_TRY here, because if TLS upgrade fails, the
    111      * transfer continues anyway - see the security discussion in the libcurl
    112      * tutorial for more details. */
    113     curl_easy_setopt(curl, CURLOPT_USE_SSL, (long)CURLUSESSL_ALL);
    114 
    115     /* If your server does not have a valid certificate, then you can disable
    116      * part of the Transport Layer Security protection by setting the
    117      * CURLOPT_SSL_VERIFYPEER and CURLOPT_SSL_VERIFYHOST options to 0 (false).
    118      *   curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
    119      *   curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
    120      * That is, in general, a bad idea. It is still better than sending your
    121      * authentication details in plain text though.  Instead, you should get
    122      * the issuer certificate (or the host certificate if the certificate is
    123      * self-signed) and add it to the set of certificates that are known to
    124      * libcurl using CURLOPT_CAINFO and/or CURLOPT_CAPATH. See docs/SSLCERTS
    125      * for more information. */
    126     curl_easy_setopt(curl, CURLOPT_CAINFO, "/path/to/certificate.pem");
    127 
    128     /* Note that this option is not strictly required, omitting it results in
    129      * libcurl sending the MAIL FROM command with empty sender data. All
    130      * autoresponses should have an empty reverse-path, and should be directed
    131      * to the address in the reverse-path which triggered them. Otherwise,
    132      * they could cause an endless loop. See RFC 5321 Section 4.5.5 for more
    133      * details.
    134      */
    135     curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM_MAIL);
    136 
    137     /* Add two recipients, in this particular case they correspond to the
    138      * To: and Cc: addressees in the header, but they could be any kind of
    139      * recipient. */
    140     recipients = curl_slist_append(recipients, TO_MAIL);
    141     recipients = curl_slist_append(recipients, CC_MAIL);
    142     curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
    143 
    144     /* We are using a callback function to specify the payload (the headers and
    145      * body of the message). You could just use the CURLOPT_READDATA option to
    146      * specify a FILE pointer to read from. */
    147     curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source);
    148     curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
    149     curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
    150 
    151     /* Since the traffic is encrypted, it is useful to turn on debug
    152      * information within libcurl to see what is happening during the
    153      * transfer.
    154      */
    155     curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
    156 
    157     /* Send the message */
    158     res = curl_easy_perform(curl);
    159 
    160     /* Check for errors */
    161     if(res != CURLE_OK)
    162       fprintf(stderr, "curl_easy_perform() failed: %s\n",
    163               curl_easy_strerror(res));
    164 
    165     /* Free the list of recipients */
    166     curl_slist_free_all(recipients);
    167 
    168     /* Always cleanup */
    169     curl_easy_cleanup(curl);
    170   }
    171 
    172   return (int)res;
    173 }