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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2019, 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.haxx.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.
*
***************************************************************************/
/* <DESC>
* Send e-mail on behalf of another user with SMTP
* </DESC>
*/
#include <stdio.h>
#include <string.h>
#include <gnurl/curl.h>
/*
* This is a simple example show how to send an email using libcurl's SMTP
* capabilities.
*
* Note that this example requires libcurl 7.66.0 or above.
*/
/* The libcurl options want plain addresses, the viewable headers in the mail
* can very well get a full name as well.
*/
#define FROM_ADDR "<ursel@example.org>"
#define SENDER_ADDR "<kurt@example.org>"
#define TO_ADDR "<addressee@example.net>"
#define FROM_MAIL "Ursel " FROM_ADDR
#define SENDER_MAIL "Kurt " SENDER_ADDR
#define TO_MAIL "A Receiver " TO_ADDR
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",
"Sender: " SENDER_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 RFC5322 */
"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 RFC5322.\r\n",
NULL
};
struct upload_status {
int lines_read;
};
static size_t payload_source(void *ptr, size_t size, size_t nmemb, void *userp)
{
struct upload_status *upload_ctx = (struct upload_status *)userp;
const char *data;
if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) {
return 0;
}
data = payload_text[upload_ctx->lines_read];
if(data) {
size_t len = strlen(data);
memcpy(ptr, data, len);
upload_ctx->lines_read++;
return len;
}
return 0;
}
int main(void)
{
CURL *curl;
CURLcode res = CURLE_OK;
struct curl_slist *recipients = NULL;
struct upload_status upload_ctx;
upload_ctx.lines_read = 0;
curl = curl_easy_init();
if(curl) {
/* This is the URL for your mailserver. In this example we connect to the
smtp-submission port as we require an authenticated connection. */
curl_easy_setopt(curl, CURLOPT_URL, "smtp://mail.example.com:587");
/* Set the username and password */
curl_easy_setopt(curl, CURLOPT_USERNAME, "kurt");
curl_easy_setopt(curl, CURLOPT_PASSWORD, "xipj3plmq");
/* Set the authorisation identity (identity to act as) */
curl_easy_setopt(curl, CURLOPT_SASL_AUTHZID, "ursel");
/* Force PLAIN authentication */
curl_easy_setopt(curl, CURLOPT_LOGIN_OPTIONS, "AUTH=PLAIN");
/* Note that this option isn't strictly required, omitting it will result
* 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_ADDR);
/* Add a recipient, in this particular case it corresponds to the
* To: addressee in the header. */
recipients = curl_slist_append(recipients, TO_ADDR);
curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
/* We're 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);
/* 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);
/* curl won't send the QUIT command until you call cleanup, so you should
* be able to re-use this connection for additional messages (setting
* CURLOPT_MAIL_FROM and CURLOPT_MAIL_RCPT as required, and calling
* curl_easy_perform() again. It may not be a good idea to keep the
* connection open for a very long time though (more than a few minutes
* may result in the server timing out the connection), and you do want to
* clean up in the end.
*/
curl_easy_cleanup(curl);
}
return (int)res;
}
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