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 2015 - 2018
11 /* Code for calling spf checks via libspf-alt. Called from acl.c. */
16 /* must be kept in numeric order */
17 static spf_result_id spf_result_id_list[] = {
25 { US"temperror", 6 }, /* RFC 4408 defined */
26 { US"permerror", 7 } /* RFC 4408 defined */
29 SPF_server_t *spf_server = NULL;
30 SPF_request_t *spf_request = NULL;
31 SPF_response_t *spf_response = NULL;
32 SPF_response_t *spf_response_2mx = NULL;
35 /* spf_init sets up a context that can be re-used for several
36 messages on the same SMTP connection (that come from the
37 same host with the same HELO string)
39 Return: Boolean success */
42 spf_init(uschar *spf_helo_domain, uschar *spf_remote_addr)
44 spf_server = SPF_server_new(SPF_DNS_CACHE, 0);
48 DEBUG(D_receive) debug_printf("spf: SPF_server_new() failed.\n");
52 if (SPF_server_set_rec_dom(spf_server, CS primary_hostname))
54 DEBUG(D_receive) debug_printf("spf: SPF_server_set_rec_dom(\"%s\") failed.\n",
60 spf_request = SPF_request_new(spf_server);
62 if ( SPF_request_set_ipv4_str(spf_request, CS spf_remote_addr)
63 && SPF_request_set_ipv6_str(spf_request, CS spf_remote_addr)
67 debug_printf("spf: SPF_request_set_ipv4_str() and "
68 "SPF_request_set_ipv6_str() failed [%s]\n", spf_remote_addr);
74 if (SPF_request_set_helo_dom(spf_request, CS spf_helo_domain))
76 DEBUG(D_receive) debug_printf("spf: SPF_set_helo_dom(\"%s\") failed.\n",
87 /* spf_process adds the envelope sender address to the existing
88 context (if any), retrieves the result, sets up expansion
89 strings and evaluates the condition outcome.
94 spf_process(const uschar **listptr, uschar *spf_envelope_sender, int action)
97 const uschar *list = *listptr;
98 uschar *spf_result_id;
99 int rc = SPF_RESULT_PERMERROR;
101 if (!(spf_server && spf_request))
102 /* no global context, assume temp error and skip to evaluation */
103 rc = SPF_RESULT_PERMERROR;
105 else if (SPF_request_set_env_from(spf_request, CS spf_envelope_sender))
106 /* Invalid sender address. This should be a real rare occurrence */
107 rc = SPF_RESULT_PERMERROR;
112 if (action == SPF_PROCESS_FALLBACK)
114 SPF_request_query_fallback(spf_request, &spf_response, CS spf_guess);
115 spf_result_guessed = TRUE;
118 SPF_request_query_mailfrom(spf_request, &spf_response);
120 /* set up expansion items */
121 spf_header_comment = US SPF_response_get_header_comment(spf_response);
122 spf_received = US SPF_response_get_received_spf(spf_response);
123 spf_result = US SPF_strresult(SPF_response_result(spf_response));
124 spf_smtp_comment = US SPF_response_get_smtp_comment(spf_response);
126 rc = SPF_response_result(spf_response);
129 /* We got a result. Now see if we should return OK or FAIL for it */
130 DEBUG(D_acl) debug_printf("SPF result is %s (%d)\n", SPF_strresult(rc), rc);
132 if (action == SPF_PROCESS_GUESS && (!strcmp (SPF_strresult(rc), "none")))
133 return spf_process(listptr, spf_envelope_sender, SPF_PROCESS_FALLBACK);
135 while ((spf_result_id = string_nextinlist(&list, &sep, NULL, 0)))
139 if ((negate = spf_result_id[0] == '!'))
142 result = Ustrcmp(spf_result_id, spf_result_id_list[rc].name) == 0;
143 if (negate != result) return OK;
153 authres_spf(gstring * g)
156 if (!spf_result) return g;
158 g = string_append(g, 2, US";\n\tspf=", spf_result);
159 if (spf_result_guessed)
160 g = string_cat(g, US" (best guess record for domain)");
162 s = expand_string(US"$sender_address_domain");
164 ? string_append(g, 2, US" smtp.mailfrom=", s)
165 : string_cat(g, US" smtp.mailfrom=<>");