1 
2 /*
3  * Copyright (C) Igor Sysoev
4  * Copyright (C) Nginx, Inc.
5  */
6 
7 
8 #include <ngx_config.h>
9 #include <ngx_core.h>
10 #include <ngx_event.h>
11 #include <ngx_mail.h>
12 #include <ngx_mail_imap_module.h>
13 
14 
15 static void *ngx_mail_imap_create_srv_conf(ngx_conf_t *cf);
16 static char *ngx_mail_imap_merge_srv_conf(ngx_conf_t *cf, void *parent,
17     void *child);
18 
19 
20 static ngx_str_t  ngx_mail_imap_default_capabilities[] = {
21     ngx_string("IMAP4"),
22     ngx_string("IMAP4rev1"),
23     ngx_string("UIDPLUS"),
24     ngx_null_string
25 };
26 
27 
28 static ngx_conf_bitmask_t  ngx_mail_imap_auth_methods[] = {
29     { ngx_string("plain"), NGX_MAIL_AUTH_PLAIN_ENABLED },
30     { ngx_string("login"), NGX_MAIL_AUTH_LOGIN_ENABLED },
31     { ngx_string("cram-md5"), NGX_MAIL_AUTH_CRAM_MD5_ENABLED },
32     { ngx_string("external"), NGX_MAIL_AUTH_EXTERNAL_ENABLED },
33     { ngx_null_string, 0 }
34 };
35 
36 
37 static ngx_str_t  ngx_mail_imap_auth_methods_names[] = {
38     ngx_string("AUTH=PLAIN"),
39     ngx_string("AUTH=LOGIN"),
40     ngx_null_string,  /* APOP */
41     ngx_string("AUTH=CRAM-MD5"),
42     ngx_string("AUTH=EXTERNAL"),
43     ngx_null_string   /* NONE */
44 };
45 
46 
47 static ngx_mail_protocol_t  ngx_mail_imap_protocol = {
48     ngx_string("imap"),
49     { 143, 993, 0, 0 },
50     NGX_MAIL_IMAP_PROTOCOL,
51 
52     ngx_mail_imap_init_session,
53     ngx_mail_imap_init_protocol,
54     ngx_mail_imap_parse_command,
55     ngx_mail_imap_auth_state,
56 
57     ngx_string("* BAD internal server error" CRLF),
58     ngx_string("* BYE SSL certificate error" CRLF),
59     ngx_string("* BYE No required SSL certificate" CRLF)
60 };
61 
62 
63 static ngx_command_t  ngx_mail_imap_commands[] = {
64 
65     { ngx_string("imap_client_buffer"),
66       NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
67       ngx_conf_set_size_slot,
68       NGX_MAIL_SRV_CONF_OFFSET,
69       offsetof(ngx_mail_imap_srv_conf_t, client_buffer_size),
70       NULL },
71 
72     { ngx_string("imap_capabilities"),
73       NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE,
74       ngx_mail_capabilities,
75       NGX_MAIL_SRV_CONF_OFFSET,
76       offsetof(ngx_mail_imap_srv_conf_t, capabilities),
77       NULL },
78 
79     { ngx_string("imap_auth"),
80       NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE,
81       ngx_conf_set_bitmask_slot,
82       NGX_MAIL_SRV_CONF_OFFSET,
83       offsetof(ngx_mail_imap_srv_conf_t, auth_methods),
84       &ngx_mail_imap_auth_methods },
85 
86       ngx_null_command
87 };
88 
89 
90 static ngx_mail_module_t  ngx_mail_imap_module_ctx = {
91     &ngx_mail_imap_protocol,               /* protocol */
92 
93     NULL,                                  /* create main configuration */
94     NULL,                                  /* init main configuration */
95 
96     ngx_mail_imap_create_srv_conf,         /* create server configuration */
97     ngx_mail_imap_merge_srv_conf           /* merge server configuration */
98 };
99 
100 
101 ngx_module_t  ngx_mail_imap_module = {
102     NGX_MODULE_V1,
103     &ngx_mail_imap_module_ctx,             /* module context */
104     ngx_mail_imap_commands,                /* module directives */
105     NGX_MAIL_MODULE,                       /* module type */
106     NULL,                                  /* init master */
107     NULL,                                  /* init module */
108     NULL,                                  /* init process */
109     NULL,                                  /* init thread */
110     NULL,                                  /* exit thread */
111     NULL,                                  /* exit process */
112     NULL,                                  /* exit master */
113     NGX_MODULE_V1_PADDING
114 };
115 
116 
117 static void *
ngx_mail_imap_create_srv_conf(ngx_conf_t * cf)118 ngx_mail_imap_create_srv_conf(ngx_conf_t *cf)
119 {
120     ngx_mail_imap_srv_conf_t  *iscf;
121 
122     iscf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_imap_srv_conf_t));
123     if (iscf == NULL) {
124         return NULL;
125     }
126 
127     iscf->client_buffer_size = NGX_CONF_UNSET_SIZE;
128 
129     if (ngx_array_init(&iscf->capabilities, cf->pool, 4, sizeof(ngx_str_t))
130         != NGX_OK)
131     {
132         return NULL;
133     }
134 
135     return iscf;
136 }
137 
138 
139 static char *
ngx_mail_imap_merge_srv_conf(ngx_conf_t * cf,void * parent,void * child)140 ngx_mail_imap_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
141 {
142     ngx_mail_imap_srv_conf_t *prev = parent;
143     ngx_mail_imap_srv_conf_t *conf = child;
144 
145     u_char      *p, *auth;
146     size_t       size;
147     ngx_str_t   *c, *d;
148     ngx_uint_t   i, m;
149 
150     ngx_conf_merge_size_value(conf->client_buffer_size,
151                               prev->client_buffer_size,
152                               (size_t) ngx_pagesize);
153 
154     ngx_conf_merge_bitmask_value(conf->auth_methods,
155                               prev->auth_methods,
156                               (NGX_CONF_BITMASK_SET
157                                |NGX_MAIL_AUTH_PLAIN_ENABLED));
158 
159 
160     if (conf->capabilities.nelts == 0) {
161         conf->capabilities = prev->capabilities;
162     }
163 
164     if (conf->capabilities.nelts == 0) {
165 
166         for (d = ngx_mail_imap_default_capabilities; d->len; d++) {
167             c = ngx_array_push(&conf->capabilities);
168             if (c == NULL) {
169                 return NGX_CONF_ERROR;
170             }
171 
172             *c = *d;
173         }
174     }
175 
176     size = sizeof("* CAPABILITY" CRLF) - 1;
177 
178     c = conf->capabilities.elts;
179     for (i = 0; i < conf->capabilities.nelts; i++) {
180         size += 1 + c[i].len;
181     }
182 
183     for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0;
184          m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED;
185          m <<= 1, i++)
186     {
187         if (m & conf->auth_methods) {
188             size += 1 + ngx_mail_imap_auth_methods_names[i].len;
189         }
190     }
191 
192     p = ngx_pnalloc(cf->pool, size);
193     if (p == NULL) {
194         return NGX_CONF_ERROR;
195     }
196 
197     conf->capability.len = size;
198     conf->capability.data = p;
199 
200     p = ngx_cpymem(p, "* CAPABILITY", sizeof("* CAPABILITY") - 1);
201 
202     for (i = 0; i < conf->capabilities.nelts; i++) {
203         *p++ = ' ';
204         p = ngx_cpymem(p, c[i].data, c[i].len);
205     }
206 
207     auth = p;
208 
209     for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0;
210          m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED;
211          m <<= 1, i++)
212     {
213         if (m & conf->auth_methods) {
214             *p++ = ' ';
215             p = ngx_cpymem(p, ngx_mail_imap_auth_methods_names[i].data,
216                            ngx_mail_imap_auth_methods_names[i].len);
217         }
218     }
219 
220     *p++ = CR; *p = LF;
221 
222 
223     size += sizeof(" STARTTLS") - 1;
224 
225     p = ngx_pnalloc(cf->pool, size);
226     if (p == NULL) {
227         return NGX_CONF_ERROR;
228     }
229 
230     conf->starttls_capability.len = size;
231     conf->starttls_capability.data = p;
232 
233     p = ngx_cpymem(p, conf->capability.data,
234                    conf->capability.len - (sizeof(CRLF) - 1));
235     p = ngx_cpymem(p, " STARTTLS", sizeof(" STARTTLS") - 1);
236     *p++ = CR; *p = LF;
237 
238 
239     size = (auth - conf->capability.data) + sizeof(CRLF) - 1
240             + sizeof(" STARTTLS LOGINDISABLED") - 1;
241 
242     p = ngx_pnalloc(cf->pool, size);
243     if (p == NULL) {
244         return NGX_CONF_ERROR;
245     }
246 
247     conf->starttls_only_capability.len = size;
248     conf->starttls_only_capability.data = p;
249 
250     p = ngx_cpymem(p, conf->capability.data,
251                    auth - conf->capability.data);
252     p = ngx_cpymem(p, " STARTTLS LOGINDISABLED",
253                    sizeof(" STARTTLS LOGINDISABLED") - 1);
254     *p++ = CR; *p = LF;
255 
256     return NGX_CONF_OK;
257 }
258