1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Experimental SPF support.
6 Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004 - 2014
8 Copyright (c) The Exim Maintainers 2016
11 /* Code for calling spf checks via libspf-alt. Called from acl.c. */
14 #ifdef EXPERIMENTAL_SPF
16 /* must be kept in numeric order */
17 static spf_result_id spf_result_id_list[] = {
25 { US"err_temp", 6 }, /* Deprecated Apr 2014 */
26 { US"err_perm", 7 }, /* Deprecated Apr 2014 */
27 { US"temperror", 6 }, /* RFC 4408 defined */
28 { US"permerror", 7 } /* RFC 4408 defined */
31 SPF_server_t *spf_server = NULL;
32 SPF_request_t *spf_request = NULL;
33 SPF_response_t *spf_response = NULL;
34 SPF_response_t *spf_response_2mx = NULL;
36 /* spf_init sets up a context that can be re-used for several
37 messages on the same SMTP connection (that come from the
38 same host with the same HELO string) */
40 int spf_init(uschar *spf_helo_domain, uschar *spf_remote_addr) {
42 spf_server = SPF_server_new(SPF_DNS_CACHE, 0);
44 if ( spf_server == NULL ) {
45 debug_printf("spf: SPF_server_new() failed.\n");
49 if (SPF_server_set_rec_dom(spf_server, CS primary_hostname)) {
50 debug_printf("spf: SPF_server_set_rec_dom(\"%s\") failed.\n", primary_hostname);
55 spf_request = SPF_request_new(spf_server);
57 if (SPF_request_set_ipv4_str(spf_request, CS spf_remote_addr)
58 && SPF_request_set_ipv6_str(spf_request, CS spf_remote_addr)) {
59 debug_printf("spf: SPF_request_set_ipv4_str() and SPF_request_set_ipv6_str() failed [%s]\n", spf_remote_addr);
65 if (SPF_request_set_helo_dom(spf_request, CS spf_helo_domain)) {
66 debug_printf("spf: SPF_set_helo_dom(\"%s\") failed.\n", spf_helo_domain);
76 /* spf_process adds the envelope sender address to the existing
77 context (if any), retrieves the result, sets up expansion
78 strings and evaluates the condition outcome. */
80 int spf_process(const uschar **listptr, uschar *spf_envelope_sender, int action) {
82 const uschar *list = *listptr;
83 uschar *spf_result_id;
84 uschar spf_result_id_buffer[128];
85 int rc = SPF_RESULT_PERMERROR;
87 if (!(spf_server && spf_request)) {
88 /* no global context, assume temp error and skip to evaluation */
89 rc = SPF_RESULT_PERMERROR;
93 if (SPF_request_set_env_from(spf_request, CS spf_envelope_sender)) {
94 /* Invalid sender address. This should be a real rare occurence */
95 rc = SPF_RESULT_PERMERROR;
100 if (action == SPF_PROCESS_FALLBACK)
101 SPF_request_query_fallback(spf_request, &spf_response, CS spf_guess);
103 SPF_request_query_mailfrom(spf_request, &spf_response);
105 /* set up expansion items */
106 spf_header_comment = US SPF_response_get_header_comment(spf_response);
107 spf_received = US SPF_response_get_received_spf(spf_response);
108 spf_result = US SPF_strresult(SPF_response_result(spf_response));
109 spf_smtp_comment = US SPF_response_get_smtp_comment(spf_response);
111 rc = SPF_response_result(spf_response);
113 /* We got a result. Now see if we should return OK or FAIL for it */
115 debug_printf("SPF result is %s (%d)\n", SPF_strresult(rc), rc);
117 if (action == SPF_PROCESS_GUESS && (!strcmp (SPF_strresult(rc), "none")))
118 return spf_process(listptr, spf_envelope_sender, SPF_PROCESS_FALLBACK);
120 while ((spf_result_id = string_nextinlist(&list, &sep,
121 spf_result_id_buffer,
122 sizeof(spf_result_id_buffer))) != NULL) {
126 /* Check for negation */
127 if (spf_result_id[0] == '!') {
132 /* Check the result identifier */
133 result = Ustrcmp(spf_result_id, spf_result_id_list[rc].name);
134 if (!negate && result==0) return OK;
135 if (negate && result!=0) return OK;