1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2016, 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.haxx.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 ***************************************************************************/
22
23/* <DESC>
24 * SMTP example using SSL
25 * </DESC>
26 */
27
28#include <stdio.h>
29#include <string.h>
30#include <curl/curl.h>
31
32/* This is a simple example showing how to send mail using libcurl's SMTP
33 * capabilities. It builds on the smtp-mail.c example to add authentication
34 * and, more importantly, transport security to protect the authentication
35 * details from being snooped.
36 *
37 * Note that this example requires libcurl 7.20.0 or above.
38 */
39
40#define FROM    "<sender@example.org>"
41#define TO      "<addressee@example.net>"
42#define CC      "<info@example.org>"
43
44static const char *payload_text[] = {
45  "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n",
46  "To: " TO "\r\n",
47  "From: " FROM " (Example User)\r\n",
48  "Cc: " CC " (Another example User)\r\n",
49  "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
50  "rfcpedant.example.org>\r\n",
51  "Subject: SMTP SSL example message\r\n",
52  "\r\n", /* empty line to divide headers from body, see RFC5322 */
53  "The body of the message starts here.\r\n",
54  "\r\n",
55  "It could be a lot of lines, could be MIME encoded, whatever.\r\n",
56  "Check RFC5322.\r\n",
57  NULL
58};
59
60struct upload_status {
61  int lines_read;
62};
63
64static size_t payload_source(void *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
69  if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) {
70    return 0;
71  }
72
73  data = payload_text[upload_ctx->lines_read];
74
75  if(data) {
76    size_t len = strlen(data);
77    memcpy(ptr, data, len);
78    upload_ctx->lines_read++;
79
80    return len;
81  }
82
83  return 0;
84}
85
86int main(void)
87{
88  CURL *curl;
89  CURLcode res = CURLE_OK;
90  struct curl_slist *recipients = NULL;
91  struct upload_status upload_ctx;
92
93  upload_ctx.lines_read = 0;
94
95  curl = curl_easy_init();
96  if(curl) {
97    /* Set username and password */
98    curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
99    curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
100
101    /* This is the URL for your mailserver. Note the use of smtps:// rather
102     * than smtp:// to request a SSL based connection. */
103    curl_easy_setopt(curl, CURLOPT_URL, "smtps://mainserver.example.net");
104
105    /* If you want to connect to a site who isn't using a certificate that is
106     * signed by one of the certs in the CA bundle you have, you can skip the
107     * verification of the server's certificate. This makes the connection
108     * A LOT LESS SECURE.
109     *
110     * If you have a CA cert for the server stored someplace else than in the
111     * default bundle, then the CURLOPT_CAPATH option might come handy for
112     * you. */
113#ifdef SKIP_PEER_VERIFICATION
114    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
115#endif
116
117    /* If the site you're connecting to uses a different host name that what
118     * they have mentioned in their server certificate's commonName (or
119     * subjectAltName) fields, libcurl will refuse to connect. You can skip
120     * this check, but this will make the connection less secure. */
121#ifdef SKIP_HOSTNAME_VERIFICATION
122    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
123#endif
124
125    /* Note that this option isn't strictly required, omitting it will result
126     * in libcurl sending the MAIL FROM command with empty sender data. All
127     * autoresponses should have an empty reverse-path, and should be directed
128     * to the address in the reverse-path which triggered them. Otherwise,
129     * they could cause an endless loop. See RFC 5321 Section 4.5.5 for more
130     * details.
131     */
132    curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM);
133
134    /* Add two recipients, in this particular case they correspond to the
135     * To: and Cc: addressees in the header, but they could be any kind of
136     * recipient. */
137    recipients = curl_slist_append(recipients, TO);
138    recipients = curl_slist_append(recipients, CC);
139    curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
140
141    /* We're using a callback function to specify the payload (the headers and
142     * body of the message). You could just use the CURLOPT_READDATA option to
143     * specify a FILE pointer to read from. */
144    curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source);
145    curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
146    curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
147
148    /* Since the traffic will be encrypted, it is very useful to turn on debug
149     * information within libcurl to see what is happening during the
150     * transfer */
151    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
152
153    /* Send the message */
154    res = curl_easy_perform(curl);
155
156    /* Check for errors */
157    if(res != CURLE_OK)
158      fprintf(stderr, "curl_easy_perform() failed: %s\n",
159              curl_easy_strerror(res));
160
161    /* Free the list of recipients */
162    curl_slist_free_all(recipients);
163
164    /* Always cleanup */
165    curl_easy_cleanup(curl);
166  }
167
168  return (int)res;
169}
170