1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel (at) 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 (at) example.org>" 41 #define TO "<addressee (at) example.net>" 42 #define CC "<info (at) 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 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 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