master-server/deps/curl/docs/examples/smtp-ssl.c
2024-05-15 15:20:32 -04:00

171 lines
5.8 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
/* <DESC>
* Send SMTP email using implicit SSL
* </DESC>
*/
#include <stdio.h>
#include <string.h>
#include <curl/curl.h>
/* This is a simple example showing how to send mail using libcurl's SMTP
* capabilities. It builds on the smtp-mail.c example to add authentication
* and, more importantly, transport security to protect the authentication
* details from being snooped.
*
* Note that this example requires libcurl 7.20.0 or above.
*/
#define FROM_MAIL "<sender@example.com>"
#define TO_MAIL "<recipient@example.com>"
#define CC_MAIL "<info@example.com>"
static const char *payload_text =
"Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
"To: " TO_MAIL "\r\n"
"From: " FROM_MAIL "\r\n"
"Cc: " CC_MAIL "\r\n"
"Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
"rfcpedant.example.org>\r\n"
"Subject: SMTP example message\r\n"
"\r\n" /* empty line to divide headers from body, see RFC 5322 */
"The body of the message starts here.\r\n"
"\r\n"
"It could be a lot of lines, could be MIME encoded, whatever.\r\n"
"Check RFC 5322.\r\n";
struct upload_status {
size_t bytes_read;
};
static size_t payload_source(char *ptr, size_t size, size_t nmemb, void *userp)
{
struct upload_status *upload_ctx = (struct upload_status *)userp;
const char *data;
size_t room = size * nmemb;
if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) {
return 0;
}
data = &payload_text[upload_ctx->bytes_read];
if(data) {
size_t len = strlen(data);
if(room < len)
len = room;
memcpy(ptr, data, len);
upload_ctx->bytes_read += len;
return len;
}
return 0;
}
int main(void)
{
CURL *curl;
CURLcode res = CURLE_OK;
struct curl_slist *recipients = NULL;
struct upload_status upload_ctx = { 0 };
curl = curl_easy_init();
if(curl) {
/* Set username and password */
curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
/* This is the URL for your mailserver. Note the use of smtps:// rather
* than smtp:// to request a SSL based connection. */
curl_easy_setopt(curl, CURLOPT_URL, "smtps://mainserver.example.net");
/* If you want to connect to a site who is not using a certificate that is
* signed by one of the certs in the CA bundle you have, you can skip the
* verification of the server's certificate. This makes the connection
* A LOT LESS SECURE.
*
* If you have a CA cert for the server stored someplace else than in the
* default bundle, then the CURLOPT_CAPATH option might come handy for
* you. */
#ifdef SKIP_PEER_VERIFICATION
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
#endif
/* If the site you are connecting to uses a different host name that what
* they have mentioned in their server certificate's commonName (or
* subjectAltName) fields, libcurl refuses to connect. You can skip this
* check, but it makes the connection insecure. */
#ifdef SKIP_HOSTNAME_VERIFICATION
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
#endif
/* Note that this option is not strictly required, omitting it results in
* libcurl sending the MAIL FROM command with empty sender data. All
* autoresponses should have an empty reverse-path, and should be directed
* to the address in the reverse-path which triggered them. Otherwise,
* they could cause an endless loop. See RFC 5321 Section 4.5.5 for more
* details.
*/
curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM_MAIL);
/* Add two recipients, in this particular case they correspond to the
* To: and Cc: addressees in the header, but they could be any kind of
* recipient. */
recipients = curl_slist_append(recipients, TO_MAIL);
recipients = curl_slist_append(recipients, CC_MAIL);
curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
/* We are using a callback function to specify the payload (the headers and
* body of the message). You could just use the CURLOPT_READDATA option to
* specify a FILE pointer to read from. */
curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source);
curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
/* Since the traffic is encrypted, it is useful to turn on debug
* information within libcurl to see what is happening during the
* transfer */
curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
/* Send the message */
res = curl_easy_perform(curl);
/* Check for errors */
if(res != CURLE_OK)
fprintf(stderr, "curl_easy_perform() failed: %s\n",
curl_easy_strerror(res));
/* Free the list of recipients */
curl_slist_free_all(recipients);
/* Always cleanup */
curl_easy_cleanup(curl);
}
return (int)res;
}