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
44 static 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
60 struct upload_status {
61 int lines_read;
62 };
63
payload_source(void * ptr,size_t size,size_t nmemb,void * userp)64 static 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
main(void)86 int 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