1IMCLIENT(3) Library Functions Manual IMCLIENT(3)
2
6 imclient library - authenticating callback interface to IMAP/IMSP
7 servers
8
10 #include <cyrus/imclient.h>
11 int imclient_connect(struct imclient **imclient, const char *host,
13 const char *port);
14 void imclient_close (struct imclient *imclient);
16 void imclient_setflags(struct imclient *imclient, intflags);
17 void imclient_clearflags (struct imclient *imclient, intflags);
18 char* imclient_servername (struct imclient *imclient);
19 void imclient_addcallback (struct imclient * imclient ,...);
20 void imclient_send (struct imclient *imclient, void (*finishproc)(),
21 void *finishrock, const char *fmt, ...);
22 void imclient_getselectinfo (struct imclient *imclient, int *fd, int *
23 wanttowrite);
24 void imclient_processoneevent (struct imclient *imclient);
25 int imclient_authenticate (struct imclient *imclient, struct
26 sasl_client **availmech, const char *service, const char *user, int
27 protallowed);
28 int imclient_havetls ();
29 int imclient_starttls (struct imclient *imclient, char *cert_file, char
30 *key_file, char *CAfile, char *CApath);
31
34 The imclient library functions are distributed with Cyrus IMAP and
35 IMSP. These functions are used for building IMAP/IMSP client software.
36 These functions handle Kerberos authentication and can set callbacks
37 based on the keyword in untagged replies or based on the command tag at
38 the end of command replies.
39 Users must link with the -lcyrus switch, and must supply a function
41 called fatal to be called in case of any error within libcyrus.a.
42 All of the imclient functions begin with the prefix imclient and takes
44 an argument of type struct imclient * as the first argument which is
45 initialized by imclient_connect and freed by imclient_close.
46 See below for a description of each function.
48 imclient_connect()
51 Connects the client server to the host. If successful, it returns
52 0 and sets the imclient argument to a pointer to an imclient
53 struct. The imclient struct represents the current connection,
54 flags, and callbacks. On failure, the current errno is returned
55 if a system call failed, -1 is returned if the host name was not
56 found, and -2 is returned if the service name was not found.
57 imclient_close()
59 Closes and frees the imclient connection.
60 imclient_setflags()
62 Sets the flags specified by the flags argument on the imclient
63 connection. Currently the only flag allowed is IMCLIENT_CONN_NON‐
64 SYNCLITERAL (this flag indicates that the server supports non-syn‐
65 chronizing literals described by the LITERAL+ extension).
66 imclient_clearflags()
68 Clears the flags specified by the flags argument on the imclient
69 connection.
70 imclient_servername()
72 Returns a char * pointer to the name of the server connected to
73 by imclient.
74 imclient_addcallback()
76 Adds an untagged data callback to the imclient connection. The
77 function imclient_addcallback takes callbacks of the type
78 imclient_proc_t which is defined to be:
79 typedef void imclient_proc_t (struct imclient *imclient, void
80 *rock, struct imclient_reply *reply);
81 and struct imclient_reply * is defined to be:
82 struct imclient_reply {
83 char *keyword;
84 long msgno;
85 char *text;
86 };
87 After the first argument imclient, there can be zero or more
89 instances of the set of keyword, flags, proc, and rock, each
90 adding or changing a single callback. Each instance adds or
91 changes the callback for keyword. The argument, flags, specifies
92 information about the parsing of the untagged data. proc and rock
93 specify the callback function and rock to invoke when the untagged
94 data is received. proc may be a null pointer, in which case no
95 function is invoked. The callback function may not call the func‐
96 tions imclient_close(), imclient_send(), imclient_eof(),
97 imclient_processoneevent(), or imclient_authenticate() on the con‐
98 nection. The callback function may over write the text of
99 untagged data.
100 imclient_send()
102 Sends a new command to the imclient connection. finishproc and
103 finnishrock are the function and rock called when the command
104 completes. functionproc may be a null pointer, in which case no
105 callback is made. The call back function may not call the func‐
106 tions imclient_close(), imclient_send(), imclient_eof(),
107 imclient_processoneevent(), or imclient_authenticate() on the con‐
108 nection. The argument, fmt , is a print like specification of the
109 command. It must not include the tag as the tag is automatically
110 added by imclient_send(). The defined %-sequences are:
111 %% for %
112 %a for an IMAP atom
113 %s for an astring (which will be quoted or literalized as
114 needed)
115 %d for a decimal
116 %u for an unsigned decimal
117 %v for #astring (argument is a null-terminated array of char *
118 which are written as space separated astrings)
119 imclient_getselectinfo()
121 Gets the information for calling select(2). fd is filled in with
122 the file descriptor to select(2) for read. wanttowrite is filled
123 in with a nonzero value if select should be used for write as
124 well.
125 imclient_processoneevent()
127 Processes one input or output event on the imclient connection.
128 imclient_authenticate()
130 Authenticates the imclient connection using one of the mechanisms
131 in availmech. The argument, user, if not NULL, specifies the user
132 to authenticate as. If the user is NULL, the current user is used.
133 The argument protallowed is a bitmask of permissible protection
134 mechanisms.
135 On success, 0 is returned. On failure (i.e., "BAD" keyboard, or
136 no authentication mechanisms worked), 1 is returned. On extreme
137 failure (premature "OK"), 2 is returned.
138 imclient_havetls()
140 Returns a Boolean indicating whether the imclient library was com‐
141 piled with TLS (SSL) support. If so, imclient_starttls() may be
142 used to secure the IMAP connection.
143 imclient_starttls()
145 Issues a STARTTLS command on an existing IMAP connection and nego‐
146 tiates the secure link. The cert_file and key_file arguments
147 specify the client certificate and secret key to use to authenti‐
148 cate ourselves to the server. If client authentication is not
149 needed, set both of these arguments to NULL.
150 The CAfile and CApath arguments specify a file or directory,
152 respectively, of CA certificates for validating server certifi‐
153 cates. (See SSL_CTX_load_verify_locations(3) for details.) If
154 both of these are NULL, the client will be unable to validate the
155 server's certificate, in which case the connection may succeed but
156 a warning will be printed to stdout.
157
160 The following code is a possible skeletion of imclient that relies on
161 Kerberos to do authentication. This code preforms an IMAP CAPABILITY
162 request and prints out the result.
163 struct sasl_client;
165 #include <cyrus/xmalloc.h> /* example uses xstrdup */
166 #include <cyrus/sasl.h>
167 #include <cyrus/imclient.h>
168 #include <stdio.h>
169 extern struct sasl_client krb_sasl_client;
171 struct sasl_client *login_sasl_client[] = {
173 &krb_sasl_client,
174 NULL
175 };
176 struct imclient *imclient;
177 char server[] = "cyrus.andrew.cmu.edu" ;
178 char port[] = "imap";
179 void fatal(char* message, int rc) {
181 fprintf(stderr, "fatal error: %s\n", message);
182 exit(rc);
183 }
184 static void callback_capability(struct imclient *imclient,
186 void *rock,
187 struct imclient_reply *reply) {
188 if (reply->text != NULL) {
189 *((char**)rock) = xstrdup( reply->text );
190 }
191 }
192 static void end_command (struct imclient *connection, void*
194 rock, struct imclient_reply *inmsg) {
195 (*(int*)rock)--;
196 }
197 main() {
199 char* capability_string;
200 int nc;
201 if (imclient_connect(&imclient, server, port)) {
203 fprintf(stderr,
204 "error: Couldn't connect to %s %s\n",
205 server, port);
206 exit(1);
207 }
208 if (imclient_authenticate(imclient, login_sasl_client, "imap"
210 /* service */,
211 NULL /* user */, SASL_PROT_ANY)) {
212 exit(1);
213 }
214 imclient_addcallback(imclient, "CAPABILITY",
216 CALLBACK_NOLITERAL,
217 callback_capability,
218 &capability_string,
219 NULL);
220 nc = 1;
222 imclient_send(imclient, end_command,
224 (void*) &nc, "CAPABILITY");
225 while(nc > 0) {
227 imclient_processoneevent(imclient);
228 }
229 if (strstr("LITERAL+", capability_string)) {
231 imclient_setflags(imclient, IMCLIENT_CONN_NONSYNCLITERAL);
232 }
233 imclient_send(imclient, NULL, NULL, "LOGOUT");
235 imclient_close(imclient);
236 printf("capability text is: %s\n", capability_string);
238 free(capability_string);
240 }
241
244 No known bugs.
245
248 cyradm, imapd, imspd, RFC2033 (IMAP LITERAL+ extension), RFC2060
249 (IMAP4rev1 specification), and select(2)
250
253 IMAP, ACAP, IMSP, Kerberos, Authentication
254
257 Copyright 1997-2002, Carnegie Mellon University. All Rights Reserved.
258 See the source distribution for copying information.
260CMU Project Cyrus IMCLIENT(3)