Commit | Line | Data |
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8523533c TK |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
8e669ac1 | 4 | |
8523533c | 5 | /* Experimental SPF support. |
5a66c31b | 6 | Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004 - 2014 |
80fea873 | 7 | License: GPL |
f9ba5e22 | 8 | Copyright (c) The Exim Maintainers 2015 - 2018 |
80fea873 | 9 | */ |
8e669ac1 | 10 | |
8523533c TK |
11 | /* Code for calling spf checks via libspf-alt. Called from acl.c. */ |
12 | ||
13 | #include "exim.h" | |
7952eef9 | 14 | #ifdef SUPPORT_SPF |
8523533c | 15 | |
6d06cf48 TK |
16 | /* must be kept in numeric order */ |
17 | static spf_result_id spf_result_id_list[] = { | |
f2ed27cf JH |
18 | /* name value */ |
19 | { US"invalid", 0}, | |
20 | { US"neutral", 1 }, | |
21 | { US"pass", 2 }, | |
22 | { US"fail", 3 }, | |
23 | { US"softfail", 4 }, | |
24 | { US"none", 5 }, | |
f2ed27cf JH |
25 | { US"temperror", 6 }, /* RFC 4408 defined */ |
26 | { US"permerror", 7 } /* RFC 4408 defined */ | |
6d06cf48 TK |
27 | }; |
28 | ||
384152a6 TK |
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; | |
8523533c | 33 | |
eb52e2cb | 34 | |
8523533c TK |
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 | |
eb52e2cb | 37 | same host with the same HELO string) |
8e669ac1 | 38 | |
eb52e2cb | 39 | Return: Boolean success */ |
8e669ac1 | 40 | |
eb52e2cb JH |
41 | BOOL |
42 | spf_init(uschar *spf_helo_domain, uschar *spf_remote_addr) | |
43 | { | |
44 | spf_server = SPF_server_new(SPF_DNS_CACHE, 0); | |
8e669ac1 | 45 | |
eb52e2cb JH |
46 | if (!spf_server) |
47 | { | |
48 | DEBUG(D_receive) debug_printf("spf: SPF_server_new() failed.\n"); | |
49 | return FALSE; | |
8523533c TK |
50 | } |
51 | ||
eb52e2cb JH |
52 | if (SPF_server_set_rec_dom(spf_server, CS primary_hostname)) |
53 | { | |
54 | DEBUG(D_receive) debug_printf("spf: SPF_server_set_rec_dom(\"%s\") failed.\n", | |
55 | primary_hostname); | |
56 | spf_server = NULL; | |
57 | return FALSE; | |
7b3a77e5 TK |
58 | } |
59 | ||
eb52e2cb JH |
60 | spf_request = SPF_request_new(spf_server); |
61 | ||
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) | |
64 | ) | |
65 | { | |
66 | DEBUG(D_receive) | |
67 | debug_printf("spf: SPF_request_set_ipv4_str() and " | |
68 | "SPF_request_set_ipv6_str() failed [%s]\n", spf_remote_addr); | |
69 | spf_server = NULL; | |
70 | spf_request = NULL; | |
71 | return FALSE; | |
8523533c TK |
72 | } |
73 | ||
eb52e2cb JH |
74 | if (SPF_request_set_helo_dom(spf_request, CS spf_helo_domain)) |
75 | { | |
76 | DEBUG(D_receive) debug_printf("spf: SPF_set_helo_dom(\"%s\") failed.\n", | |
77 | spf_helo_domain); | |
78 | spf_server = NULL; | |
79 | spf_request = NULL; | |
80 | return FALSE; | |
8523533c | 81 | } |
8e669ac1 | 82 | |
eb52e2cb | 83 | return TRUE; |
8523533c TK |
84 | } |
85 | ||
86 | ||
87 | /* spf_process adds the envelope sender address to the existing | |
88 | context (if any), retrieves the result, sets up expansion | |
eb52e2cb | 89 | strings and evaluates the condition outcome. |
f9ba5e22 | 90 | |
eb52e2cb JH |
91 | Return: OK/FAIL */ |
92 | ||
93 | int | |
94 | spf_process(const uschar **listptr, uschar *spf_envelope_sender, int action) | |
95 | { | |
96 | int sep = 0; | |
97 | const uschar *list = *listptr; | |
98 | uschar *spf_result_id; | |
99 | int rc = SPF_RESULT_PERMERROR; | |
100 | ||
101 | if (!(spf_server && spf_request)) | |
102 | /* no global context, assume temp error and skip to evaluation */ | |
103 | rc = SPF_RESULT_PERMERROR; | |
104 | ||
105 | else if (SPF_request_set_env_from(spf_request, CS spf_envelope_sender)) | |
aded2255 | 106 | /* Invalid sender address. This should be a real rare occurrence */ |
eb52e2cb JH |
107 | rc = SPF_RESULT_PERMERROR; |
108 | ||
109 | else | |
110 | { | |
8523533c | 111 | /* get SPF result */ |
65a7d8c3 | 112 | if (action == SPF_PROCESS_FALLBACK) |
87e9d061 | 113 | { |
7156b1ef | 114 | SPF_request_query_fallback(spf_request, &spf_response, CS spf_guess); |
87e9d061 JH |
115 | spf_result_guessed = TRUE; |
116 | } | |
65a7d8c3 NM |
117 | else |
118 | SPF_request_query_mailfrom(spf_request, &spf_response); | |
8523533c TK |
119 | |
120 | /* set up expansion items */ | |
5903c6ff JH |
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); | |
8523533c | 125 | |
384152a6 | 126 | rc = SPF_response_result(spf_response); |
eb52e2cb JH |
127 | } |
128 | ||
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); | |
131 | ||
132 | if (action == SPF_PROCESS_GUESS && (!strcmp (SPF_strresult(rc), "none"))) | |
133 | return spf_process(listptr, spf_envelope_sender, SPF_PROCESS_FALLBACK); | |
134 | ||
135 | while ((spf_result_id = string_nextinlist(&list, &sep, NULL, 0))) | |
136 | { | |
137 | BOOL negate, result; | |
138 | ||
139 | if ((negate = spf_result_id[0] == '!')) | |
140 | spf_result_id++; | |
141 | ||
142 | result = Ustrcmp(spf_result_id, spf_result_id_list[rc].name) == 0; | |
143 | if (negate != result) return OK; | |
144 | } | |
8523533c | 145 | |
eb52e2cb JH |
146 | /* no match */ |
147 | return FAIL; | |
8523533c TK |
148 | } |
149 | ||
dfbcb5ac JH |
150 | |
151 | ||
152 | gstring * | |
153 | authres_spf(gstring * g) | |
154 | { | |
87e9d061 | 155 | uschar * s; |
dfbcb5ac JH |
156 | if (!spf_result) return g; |
157 | ||
87e9d061 JH |
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)"); | |
161 | ||
162 | s = expand_string(US"$sender_address_domain"); | |
163 | return s && *s | |
164 | ? string_append(g, 2, US" smtp.mailfrom=", s) | |
165 | : string_cat(g, US" smtp.mailfrom=<>"); | |
dfbcb5ac JH |
166 | } |
167 | ||
168 | ||
8523533c | 169 | #endif |