diff options
| -rw-r--r-- | docs/examples/Makefile.inc | 2 | ||||
| -rw-r--r-- | docs/examples/smtp-tls.c | 135 |
2 files changed, 136 insertions, 1 deletions
diff --git a/docs/examples/Makefile.inc b/docs/examples/Makefile.inc index a9379f745..9a2b48ea1 100644 --- a/docs/examples/Makefile.inc +++ b/docs/examples/Makefile.inc @@ -4,7 +4,7 @@ check_PROGRAMS = 10-at-a-time anyauthput cookie_interface debug fileupload \ https multi-app multi-debugcallback multi-double multi-post multi-single \ persistant post-callback postit2 sepheaders simple simplepost simplessl \ sendrecv httpcustomheader certinfo chkspeed ftpgetinfo ftp-wildcard \ - smtp-multi simplesmtp + smtp-multi simplesmtp smtp-tls # These examples require external dependencies that may not be commonly # available on POSIX systems, so don't bother attempting to compile them here. diff --git a/docs/examples/smtp-tls.c b/docs/examples/smtp-tls.c new file mode 100644 index 000000000..58719ade2 --- /dev/null +++ b/docs/examples/smtp-tls.c @@ -0,0 +1,135 @@ +/***************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + */ + +#include <stdio.h> +#include <string.h> +#include <curl/curl.h> + +/* This is a simple example showing how to send mail using libcurl's SMTP + * capabilities. It builds on the simplesmtp.c example, adding some + * authentication and transport security. + */ + +#define FROM "sender@example.org" +#define TO "addressee@example.net" +#define CC "info@example.org" + +static const char *payload_text[]={ + "Date: Mon, 29 Nov 2010 21:54:29 +1100\n", + "To: " TO "\n", + "From: " FROM "(Example User)\n", + "Cc: " CC "(Another example User)\n" + "Subject: SMTP TLS example message\n", + "\n", /* empty line to divide headers from body, see RFC5322 */ + "The body of the message starts here.\n", + "\n", + "It could be a lot of lines, could be MIME encoded, whatever.\n", + "Check RFC5322.\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; + 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. Note the use of port 587 here, + * instead of the normal SMTP port (25). Port 587 is commonly used for + * secure mail submission (see RFC4403), but you should use whatever + * matches your server configuration. */ + curl_easy_setopt(curl, CURLOPT_URL, "smtp://mainserver.example.net:587"); + + /* In this example, we'll start with a plain text connection, and upgrade + * to Transport Layer Security (TLS) using the STARTTLS command. Be careful + * of using CURLUSESSL_TRY here, because if TLS upgrade fails, the transfer + * will continue anyway - see the security discussion in the libcurl + * tutorial for more details. */ + curl_easy_setopt(curl, CURLOPT_USE_SSL, CURLUSESSL_ALL); + + /* If your server doesn't have a valid certificate, then you can disable + * part of the Transport Layer Security protection by setting the + * CURLOPT_SSL_VERIFYPEER and CURLOPT_SSL_VERIFYHOST options to 0 (false). + * curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0); + * curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0); + * That is, in general, a bad idea. It is still better than sending your + * authentication details in plain text though. + * Instead, you should get the issuer certificate (or the host certificate + * if the certificate is self-signed) and add it to the set of certificates + * that are known to libcurl using CURLOPT_CAINFO and/or CURLOPT_CAPATH. See + * docs/SSLCERTS for more information. + */ + curl_easy_setopt(curl, CURLOPT_CAINFO, "/path/to/certificate.pem"); + + /* A common reason for requiring transport security is to protect + * authentication details (user names and passwords) from being "snooped" + * on the network. Here is how the user name and password are provided: */ + curl_easy_setopt(curl, CURLOPT_USERNAME, "user@example.net"); + curl_easy_setopt(curl, CURLOPT_PASSWORD, "P@ssw0rd"); + + /* value for envelope reverse-path */ + curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM); + /* Add two recipients, in this particular case they correspond to the + * To: and Cc: addressees in the header, but they could be any kind of + * recipient. */ + recipients = curl_slist_append(recipients, TO); + recipients = curl_slist_append(recipients, CC); + curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients); + + /* In this case, we're using a callback function to specify the data. 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); + + /* Since the traffic will be encrypted, it is very useful to turn on debug + * information within libcurl to see what is happening during the transfer. + */ + curl_easy_setopt(curl, CURLOPT_VERBOSE, 1); + + /* send the message (including headers) */ + res = curl_easy_perform(curl); + + /* free the list of recipients and clean up */ + curl_slist_free_all(recipients); + curl_easy_cleanup(curl); + } + return 0; +} |