IMCLIENT(3) | Cyrus IMAP | IMCLIENT(3) |
imclient - Cyrus IMAP documentation
Authenticating callback interface to IMAP/IMSP servers
#include <cyrus/imclient.h> int imclient_connect(struct imclient **imclient , const char *host ,
const char *port); void imclient_close (struct imclient *imclient); void imclient_setflags(struct imclient *imclient , int flags); void imclient_clearflags (struct imclient *imclient , int flags); char* imclient_servername (struct imclient *imclient); void imclient_addcallback (struct imclient *imclient,...); void imclient_send (struct imclient *imclient, void (*finishproc)(),
void *finishrock, const char *fmt,...); void imclient_getselectinfo (struct imclient *imclient, int * fd,
int * wanttowrite); void imclient_processoneevent (struct imclient *imclient); int imclient_authenticate (struct imclient *imclient,
struct sasl_client **availmech, const char *service,
const char *user, int protallowed); int imclient_havetls (); int imclient_starttls (struct imclient *imclient, char *cert_file,
char *key_file, char *CAfile, char *CApath);
The imclient library functions are distributed with Cyrus IMAP and IMSP. These functions are used for building IMAP/IMSP client software. These functions handle Kerberos authentication and can set callbacks based on the keyword in untagged replies or based on the command tag at the end of command replies.
Users must link with the -lcyrus switch, and must supply a function called fatal to be called in case of any error within libcyrus.la.
All of the imclient functions begin with the prefix imclient and take an argument of type struct imclient * as the first argument which is initialized by imclient_connect and freed by imclient_close.
See below for a description of each function.
typedef void imclient_proc_t (struct imclient *imclient, void *rock, struct imclient_reply *reply);
and struct imclient_reply * is defined to be:
struct imclient_reply {
char *keyword;
long msgno;
char *text; };
After the first argument, imclient, there can be zero or more instances of the set of keyword, flags, proc, and rock, each adding or changing a single callback. Each instance adds or changes the callback for keyword. The argument flags specifies information about the parsing of the untagged data. proc and rock specify the callback function and rock to invoke when the untagged data is received. proc may be a null pointer, in which case no function is invoked. The callback function may not call the functions imclient_close(), imclient_send(), imclient_eof(), imclient_processoneevent(), or imclient_authenticate() on the connection. The callback function may overwrite the text of untagged data.
The defined %-sequences are:
%% for % %a for an IMAP atom %s for an astring (which will be quoted or literalized as needed) %d for a decimal %u for an unsigned decimal %v for #astring (argument is a null-terminated array of char * which are written as space separated astrings)
The CAfile and CApath arguments specify a file or directory, respectively, of CA certificates for validating server certificates. (See SSL_CTX_load_verify_locations(3) for details.) If both of these are NULL, the client will be unable to validate the server's certificate, in which case the connection may succeed but a warning will be printed to stdout.
The following code is a possible skeleton of imclient that relies on Kerberos to do authentication. This code performs an IMAP CAPABILITY request and prints out the result.
#include <cyrus/xmalloc.h> /* example uses xstrdup */ #include <cyrus/sasl.h> #include <cyrus/imclient.h> #include <stdio.h> extern struct sasl_client krb_sasl_client; struct sasl_client *login_sasl_client[] = {
&krb_sasl_client,
NULL }; struct imclient *imclient; char server[] = "cyrus.andrew.cmu.edu" ; char port[] = "imap"; void fatal(char* message, int rc) {
fprintf(stderr, "fatal error: %s\en", message);
exit(rc); } static void callback_capability(struct imclient *imclient,
void *rock,
struct imclient_reply *reply) {
if (reply->text != NULL) {
*((char**)rock) = xstrdup( reply->text );
} } static void end_command(struct imclient *connection, void*
rock, struct imclient_reply *inmsg) {
(*(int*)rock)--; } main() {
char* capability_string;
int nc;
if (imclient_connect(&imclient, server, port)) {
fprintf(stderr,
"error: Couldn't connect to %s %s\en",
server, port);
exit(1);
}
if (imclient_authenticate(imclient, login_sasl_client, "imap"
/* service */,
NULL /* user */, SASL_PROT_ANY)) {
exit(1);
}
imclient_addcallback(imclient, "CAPABILITY",
CALLBACK_NOLITERAL,
callback_capability,
&capability_string,
NULL);
nc = 1;
imclient_send(imclient, end_command,
(void*) &nc, "CAPABILITY");
while(nc > 0) {
imclient_processoneevent(imclient);
}
if (strstr("LITERAL+", capability_string)) {
imclient_setflags(imclient, IMCLIENT_CONN_NONSYNCLITERAL);
}
imclient_send(imclient, NULL, NULL, "LOGOUT");
imclient_close(imclient);
printf("capability text is: %s\en", capability_string);
free(capability_string); }
No known bugs.
cyradm(8), imapd(8), RFC 2033 (IMAP LITERAL+ extension), RFC 2060 (IMAP4rev1 specification), and select(2)
IMAP, ACAP, IMSP, Kerberos, Authentication
The Cyrus Team, Nic Bernstein (Onlight)
1993-2017, The Cyrus Team
August 10, 2018 | 3.0.8 |