1/*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2014, 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 http://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#include <stdio.h> 23#include <string.h> 24#include <curl/curl.h> 25 26/* This is a simple example showing how to send mail using libcurl's SMTP 27 * capabilities. It builds on the smtp-mail.c example to add authentication 28 * and, more importantly, transport security to protect the authentication 29 * details from being snooped. 30 * 31 * Note that this example requires libcurl 7.20.0 or above. 32 */ 33 34#define FROM "<sender@example.org>" 35#define TO "<addressee@example.net>" 36#define CC "<info@example.org>" 37 38static const char *payload_text[] = { 39 "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n", 40 "To: " TO "\r\n", 41 "From: " FROM "(Example User)\r\n", 42 "Cc: " CC "(Another example User)\r\n", 43 "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@rfcpedant.example.org>\r\n", 44 "Subject: SMTP TLS example message\r\n", 45 "\r\n", /* empty line to divide headers from body, see RFC5322 */ 46 "The body of the message starts here.\r\n", 47 "\r\n", 48 "It could be a lot of lines, could be MIME encoded, whatever.\r\n", 49 "Check RFC5322.\r\n", 50 NULL 51}; 52 53struct upload_status { 54 int lines_read; 55}; 56 57static size_t payload_source(void *ptr, size_t size, size_t nmemb, void *userp) 58{ 59 struct upload_status *upload_ctx = (struct upload_status *)userp; 60 const char *data; 61 62 if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) { 63 return 0; 64 } 65 66 data = payload_text[upload_ctx->lines_read]; 67 68 if(data) { 69 size_t len = strlen(data); 70 memcpy(ptr, data, len); 71 upload_ctx->lines_read++; 72 73 return len; 74 } 75 76 return 0; 77} 78 79int main(void) 80{ 81 CURL *curl; 82 CURLcode res = CURLE_OK; 83 struct curl_slist *recipients = NULL; 84 struct upload_status upload_ctx; 85 86 upload_ctx.lines_read = 0; 87 88 curl = curl_easy_init(); 89 if(curl) { 90 /* Set username and password */ 91 curl_easy_setopt(curl, CURLOPT_USERNAME, "user"); 92 curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret"); 93 94 /* This is the URL for your mailserver. Note the use of port 587 here, 95 * instead of the normal SMTP port (25). Port 587 is commonly used for 96 * secure mail submission (see RFC4403), but you should use whatever 97 * matches your server configuration. */ 98 curl_easy_setopt(curl, CURLOPT_URL, "smtp://mainserver.example.net:587"); 99 100 /* In this example, we'll start with a plain text connection, and upgrade 101 * to Transport Layer Security (TLS) using the STARTTLS command. Be careful 102 * of using CURLUSESSL_TRY here, because if TLS upgrade fails, the transfer 103 * will continue anyway - see the security discussion in the libcurl 104 * tutorial for more details. */ 105 curl_easy_setopt(curl, CURLOPT_USE_SSL, (long)CURLUSESSL_ALL); 106 107 /* If your server doesn't have a valid certificate, then you can disable 108 * part of the Transport Layer Security protection by setting the 109 * CURLOPT_SSL_VERIFYPEER and CURLOPT_SSL_VERIFYHOST options to 0 (false). 110 * curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L); 111 * curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L); 112 * That is, in general, a bad idea. It is still better than sending your 113 * authentication details in plain text though. 114 * Instead, you should get the issuer certificate (or the host certificate 115 * if the certificate is self-signed) and add it to the set of certificates 116 * that are known to libcurl using CURLOPT_CAINFO and/or CURLOPT_CAPATH. See 117 * docs/SSLCERTS for more information. */ 118 curl_easy_setopt(curl, CURLOPT_CAINFO, "/path/to/certificate.pem"); 119 120 /* Note that this option isn't strictly required, omitting it will result in 121 * libcurl sending the MAIL FROM command with empty sender data. All 122 * autoresponses should have an empty reverse-path, and should be directed 123 * to the address in the reverse-path which triggered them. Otherwise, they 124 * could cause an endless loop. See RFC 5321 Section 4.5.5 for more details. 125 */ 126 curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM); 127 128 /* Add two recipients, in this particular case they correspond to the 129 * To: and Cc: addressees in the header, but they could be any kind of 130 * recipient. */ 131 recipients = curl_slist_append(recipients, TO); 132 recipients = curl_slist_append(recipients, CC); 133 curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients); 134 135 /* We're using a callback function to specify the payload (the headers and 136 * body of the message). You could just use the CURLOPT_READDATA option to 137 * specify a FILE pointer to read from. */ 138 curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source); 139 curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx); 140 curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L); 141 142 /* Since the traffic will be encrypted, it is very useful to turn on debug 143 * information within libcurl to see what is happening during the transfer. 144 */ 145 curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L); 146 147 /* Send the message */ 148 res = curl_easy_perform(curl); 149 150 /* Check for errors */ 151 if(res != CURLE_OK) 152 fprintf(stderr, "curl_easy_perform() failed: %s\n", 153 curl_easy_strerror(res)); 154 155 /* Free the list of recipients */ 156 curl_slist_free_all(recipients); 157 158 /* Always cleanup */ 159 curl_easy_cleanup(curl); 160 } 161 162 return (int)res; 163} 164