+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+/* DMARC support.
+ Copyright (c) The Exim Maintainers 2019 - 2024
+ Copyright (c) Todd Lyons <tlyons@exim.org> 2012 - 2014
+ License: GPL */
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/* Portions Copyright (c) 2012, 2013, The Trusted Domain Project;
+ All rights reserved, licensed for use per LICENSE.opendmarc. */
+
+/* Code for calling dmarc checks via libopendmarc. Called from acl.c. */
+
+#include "../exim.h"
+#ifdef SUPPORT_DMARC
+# if !defined SUPPORT_SPF
+# error SPF must also be enabled for DMARC
+# elif defined DISABLE_DKIM
+# error DKIM must also be enabled for DMARC
+# else
+
+# include "../functions.h"
+# include "dmarc.h"
+# include "../pdkim/pdkim.h"
+
+OPENDMARC_LIB_T dmarc_ctx;
+DMARC_POLICY_T *dmarc_pctx = NULL;
+OPENDMARC_STATUS_T libdm_status, action, dmarc_policy;
+OPENDMARC_STATUS_T da, sa, action;
+BOOL dmarc_abort = FALSE;
+uschar *dmarc_pass_fail = US"skipped";
+header_line *from_header = NULL;
+
+misc_module_info * spf_mod_info;
+SPF_response_t *spf_response_p;
+int dmarc_spf_ares_result = 0;
+uschar *spf_sender_domain = NULL;
+uschar *spf_human_readable = NULL;
+u_char *header_from_sender = NULL;
+int history_file_status = DMARC_HIST_OK;
+
+typedef struct dmarc_exim_p {
+ uschar *name;
+ int value;
+} dmarc_exim_p;
+
+static dmarc_exim_p dmarc_policy_description[] = {
+ /* name value */
+ { US"", DMARC_RECORD_P_UNSPECIFIED },
+ { US"none", DMARC_RECORD_P_NONE },
+ { US"quarantine", DMARC_RECORD_P_QUARANTINE },
+ { US"reject", DMARC_RECORD_P_REJECT },
+ { NULL, 0 }
+};
+
+
+/* $variables */
+uschar * dmarc_domain_policy = NULL; /* Declared policy of used domain */
+uschar * dmarc_status = NULL; /* One word value */
+uschar * dmarc_status_text = NULL; /* Human readable value */
+uschar * dmarc_used_domain = NULL; /* Domain libopendmarc chose for DMARC policy lookup */
+
+/* options */
+uschar * dmarc_forensic_sender = NULL; /* Set sender address for forensic reports */
+uschar * dmarc_history_file = NULL; /* File to store dmarc results */
+uschar * dmarc_tld_file = NULL; /* Mozilla TLDs text file */
+
+
+/* One-time initialisation for dmarc. Ensure the spf module is available. */
+
+static BOOL
+dmarc_init(void *)
+{
+uschar * errstr;
+if (!(spf_mod_info = misc_mod_find(US"spf", &errstr)))
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+ "dmarc: failed to find SPF module: %s", errstr);
+return TRUE;
+}
+
+static gstring *
+dmarc_version_report(gstring * g)
+{
+return string_fmt_append(g, "Library version: dmarc: Compile: %d.%d.%d.%d\n",
+ (OPENDMARC_LIB_VERSION & 0xff000000) >> 24,
+ (OPENDMARC_LIB_VERSION & 0x00ff0000) >> 16,
+ (OPENDMARC_LIB_VERSION & 0x0000ff00) >> 8,
+ (OPENDMARC_LIB_VERSION & 0x000000ff));
+}
+
+
+/* Accept an error_block struct, initialize if empty, parse to the
+end, and append the two strings passed to it. Used for adding
+variable amounts of value:pair data to the forensic emails. */
+
+static error_block *
+add_to_eblock(error_block *eblock, uschar *t1, uschar *t2)
+{
+error_block *eb = store_malloc(sizeof(error_block));
+if (!eblock)
+ eblock = eb;
+else
+ {
+ /* Find the end of the eblock struct and point it at eb */
+ error_block *tmp = eblock;
+ while(tmp->next)
+ tmp = tmp->next;
+ tmp->next = eb;
+ }
+eb->text1 = t1;
+eb->text2 = t2;
+eb->next = NULL;
+return eblock;
+}
+
+/* dmarc_msg_init sets up a context that can be re-used for several
+messages on the same SMTP connection (that come from the
+same host with the same HELO string).
+However, we seem to only use it for one; we destroy some sort of context
+at the tail end of dmarc_process(). */
+
+static int
+dmarc_msg_init()
+{
+int *netmask = NULL; /* Ignored */
+int is_ipv6 = 0;
+
+/* Set some sane defaults. Also clears previous results when
+multiple messages in one connection. */
+
+dmarc_pctx = NULL;
+dmarc_status = US"none";
+dmarc_abort = FALSE;
+dmarc_pass_fail = US"skipped";
+dmarc_used_domain = US"";
+f.dmarc_has_been_checked = FALSE;
+header_from_sender = NULL;
+spf_response_p = NULL;
+spf_sender_domain = NULL;
+spf_human_readable = NULL;
+
+/* ACLs have "control=dmarc_disable_verify" */
+if (f.dmarc_disable_verify)
+ return OK;
+
+(void) memset(&dmarc_ctx, '\0', sizeof dmarc_ctx);
+dmarc_ctx.nscount = 0;
+libdm_status = opendmarc_policy_library_init(&dmarc_ctx);
+if (libdm_status != DMARC_PARSE_OKAY)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "DMARC failure to init library: %s",
+ opendmarc_policy_status_to_str(libdm_status));
+ dmarc_abort = TRUE;
+ }
+if (!dmarc_tld_file || !*dmarc_tld_file)
+ {
+ DEBUG(D_receive) debug_printf_indent("DMARC: no dmarc_tld_file\n");
+ dmarc_abort = TRUE;
+ }
+else if (opendmarc_tld_read_file(CS dmarc_tld_file, NULL, NULL, NULL))
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "DMARC failure to load tld list '%s': %s",
+ dmarc_tld_file, strerror(errno));
+ dmarc_abort = TRUE;
+ }
+if (!sender_host_address)
+ {
+ DEBUG(D_receive) debug_printf_indent("DMARC: no sender_host_address\n");
+ dmarc_abort = TRUE;
+ }
+/* This catches locally originated email and startup errors above. */
+if (!dmarc_abort)
+ {
+ is_ipv6 = string_is_ip_address(sender_host_address, netmask) == 6;
+ if (!(dmarc_pctx = opendmarc_policy_connect_init(sender_host_address, is_ipv6)))
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "DMARC failure creating policy context: ip=%s", sender_host_address);
+ dmarc_abort = TRUE;
+ }
+ }
+
+return OK;
+}
+
+
+static void
+dmarc_smtp_reset(void)
+{
+dmarc_domain_policy = dmarc_status = dmarc_status_text =
+dmarc_used_domain = NULL;
+}
+
+
+/* dmarc_store_data stores the header data so that subsequent dmarc_process can
+access the data.
+Called after the entire message has been received, with the From: header. */
+
+static int
+dmarc_store_data(header_line * hdr)
+{
+/* No debug output because would change every test debug output */
+if (!f.dmarc_disable_verify)
+ from_header = hdr;
+return OK;
+}
+
+
+static void
+dmarc_send_forensic_report(u_char ** ruf)
+{
+uschar *recipient, *save_sender;
+BOOL send_status = FALSE;
+error_block *eblock = NULL;
+FILE *message_file = NULL;
+
+/* Earlier ACL does not have *required* control=dmarc_enable_forensic */
+if (!f.dmarc_enable_forensic)
+ return;
+
+if ( dmarc_policy == DMARC_POLICY_REJECT && action == DMARC_RESULT_REJECT
+ || dmarc_policy == DMARC_POLICY_QUARANTINE && action == DMARC_RESULT_QUARANTINE
+ || dmarc_policy == DMARC_POLICY_NONE && action == DMARC_RESULT_REJECT
+ || dmarc_policy == DMARC_POLICY_NONE && action == DMARC_RESULT_QUARANTINE
+ )
+ if (ruf)
+ {
+ eblock = add_to_eblock(eblock, US"Sender Domain", dmarc_used_domain);
+ eblock = add_to_eblock(eblock, US"Sender IP Address", sender_host_address);
+ eblock = add_to_eblock(eblock, US"Received Date", tod_stamp(tod_full));
+ eblock = add_to_eblock(eblock, US"SPF Alignment",
+ sa == DMARC_POLICY_SPF_ALIGNMENT_PASS ? US"yes" : US"no");
+ eblock = add_to_eblock(eblock, US"DKIM Alignment",
+ da == DMARC_POLICY_DKIM_ALIGNMENT_PASS ? US"yes" : US"no");
+ eblock = add_to_eblock(eblock, US"DMARC Results", dmarc_status_text);
+
+ for (int c = 0; ruf[c]; c++)
+ {
+ recipient = string_copylc(ruf[c]);
+ if (Ustrncmp(recipient, "mailto:",7))
+ continue;
+ /* Move to first character past the colon */
+ recipient += 7;
+ DEBUG(D_receive)
+ debug_printf_indent("DMARC forensic report to %s%s\n", recipient,
+ (host_checking || f.running_in_test_harness) ? " (not really)" : "");
+ if (host_checking || f.running_in_test_harness)
+ continue;
+
+ if (!moan_send_message(recipient, ERRMESS_DMARC_FORENSIC, eblock,
+ header_list, message_file, NULL))
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failure to send DMARC forensic report to %s", recipient);
+ }
+ }
+}
+
+
+/* Look up a DNS dmarc record for the given domain. Return it or NULL */
+
+static uschar *
+dmarc_dns_lookup(uschar * dom)
+{
+dns_answer * dnsa = store_get_dns_answer();
+dns_scan dnss;
+int rc = dns_lookup(dnsa, string_sprintf("_dmarc.%s", dom), T_TXT, NULL);
+
+if (rc == DNS_SUCCEED)
+ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
+ rr = dns_next_rr(dnsa, &dnss, RESET_NEXT))
+ if (rr->type == T_TXT && rr->size > 3)
+ {
+ uschar *record = string_copyn_taint(US rr->data, rr->size, GET_TAINTED);
+ store_free_dns_answer(dnsa);
+ return record;
+ }
+store_free_dns_answer(dnsa);
+return NULL;
+}
+
+
+static int
+dmarc_write_history_file(const gstring * dkim_history_buffer)
+{
+int history_file_fd = 0;
+ssize_t written_len;
+int tmp_ans;
+u_char ** rua; /* aggregate report addressees */
+gstring * g;
+
+if (!dmarc_history_file)
+ {
+ DEBUG(D_receive) debug_printf_indent("DMARC history file not set\n");
+ return DMARC_HIST_DISABLED;
+ }
+if (!host_checking)
+ {
+ uschar * s = string_copy(dmarc_history_file); /* need a writeable copy */
+ if ((history_file_fd = log_open_as_exim(s)) < 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failure to create DMARC history file: %s: %s",
+ s, strerror(errno));
+ return DMARC_HIST_FILE_ERR;
+ }
+ }
+
+/* Generate the contents of the history file entry */
+
+g = string_fmt_append(NULL,
+ "job %s\nreporter %s\nreceived %ld\nipaddr %s\nfrom %s\nmfrom %s\n",
+ message_id, primary_hostname, time(NULL), sender_host_address,
+ header_from_sender, expand_string(US"$sender_address_domain"));
+
+if (spf_response_p)
+ g = string_fmt_append(g, "spf %d\n", dmarc_spf_ares_result);
+
+if (dkim_history_buffer)
+ g = string_fmt_append(g, "%Y", dkim_history_buffer);
+
+g = string_fmt_append(g, "pdomain %s\npolicy %d\n",
+ dmarc_used_domain, dmarc_policy);
+
+if ((rua = opendmarc_policy_fetch_rua(dmarc_pctx, NULL, 0, 1)))
+ for (tmp_ans = 0; rua[tmp_ans]; tmp_ans++)
+ g = string_fmt_append(g, "rua %s\n", rua[tmp_ans]);
+else
+ g = string_catn(g, US"rua -\n", 6);
+
+opendmarc_policy_fetch_pct(dmarc_pctx, &tmp_ans);
+g = string_fmt_append(g, "pct %d\n", tmp_ans);
+
+opendmarc_policy_fetch_adkim(dmarc_pctx, &tmp_ans);
+g = string_fmt_append(g, "adkim %d\n", tmp_ans);
+
+opendmarc_policy_fetch_aspf(dmarc_pctx, &tmp_ans);
+g = string_fmt_append(g, "aspf %d\n", tmp_ans);
+
+opendmarc_policy_fetch_p(dmarc_pctx, &tmp_ans);
+g = string_fmt_append(g, "p %d\n", tmp_ans);
+
+opendmarc_policy_fetch_sp(dmarc_pctx, &tmp_ans);
+g = string_fmt_append(g, "sp %d\n", tmp_ans);
+
+g = string_fmt_append(g, "align_dkim %d\nalign_spf %d\naction %d\n",
+ da, sa, action);
+
+#if DMARC_API >= 100400
+# ifdef EXPERIMENTAL_ARC
+g = arc_dmarc_hist_append(g);
+# else
+g = string_fmt_append(g, "arc %d\narc_policy %d json:[]\n",
+ ARES_RESULT_UNKNOWN, DMARC_ARC_POLICY_RESULT_UNUSED);
+# endif
+#endif
+
+/* Write the contents to the history file */
+DEBUG(D_receive)
+ {
+ debug_printf_indent("DMARC logging history data for opendmarc reporting%s\n",
+ host_checking ? " (not really)" : "");
+ debug_printf_indent("DMARC history data for debugging:\n");
+ expand_level++;
+ debug_printf_indent("%Y", g);
+ expand_level--;
+ }
+
+if (!host_checking)
+ {
+ written_len = write_to_fd_buf(history_file_fd,
+ g->s,
+ gstring_length(g));
+ if (written_len == 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "failure to write to DMARC history file: %s",
+ dmarc_history_file);
+ return DMARC_HIST_WRITE_ERR;
+ }
+ (void)close(history_file_fd);
+ }
+return DMARC_HIST_OK;
+}
+
+
+/* dmarc_process adds the envelope sender address to the existing
+context (if any), retrieves the result, sets up expansion
+strings and evaluates the condition outcome.
+Called for the first ACL dmarc= condition. */
+
+static int
+dmarc_process(void)
+{
+int sr, origin; /* used in SPF section */
+int dmarc_spf_result = 0; /* stores spf into dmarc conn ctx */
+int tmp_ans, c;
+pdkim_signature * sig = dkim_signatures;
+uschar * rr;
+BOOL has_dmarc_record = TRUE;
+u_char ** ruf; /* forensic report addressees, if called for */
+
+/* ACLs have "control=dmarc_disable_verify" */
+if (f.dmarc_disable_verify)
+ return OK;
+
+/* Store the header From: sender domain for this part of DMARC.
+If there is no from_header struct, then it's likely this message
+is locally generated and relying on fixups to add it. Just skip
+the entire DMARC system if we can't find a From: header....or if
+there was a previous error. */
+
+if (!from_header)
+ {
+ DEBUG(D_receive) debug_printf_indent("DMARC: no From: header\n");
+ dmarc_abort = TRUE;
+ }
+else if (!dmarc_abort)
+ {
+ uschar * errormsg;
+ int dummy, domain;
+ uschar * p;
+ uschar saveend;
+
+ f.parse_allow_group = TRUE;
+ p = parse_find_address_end(from_header->text, FALSE);
+ saveend = *p; *p = '\0';
+ if ((header_from_sender = parse_extract_address(from_header->text, &errormsg,
+ &dummy, &dummy, &domain, FALSE)))
+ header_from_sender += domain;
+ *p = saveend;
+
+ /* The opendmarc library extracts the domain from the email address, but
+ only try to store it if it's not empty. Otherwise, skip out of DMARC. */
+
+ if (!header_from_sender || (strcmp( CCS header_from_sender, "") == 0))
+ dmarc_abort = TRUE;
+ libdm_status = dmarc_abort
+ ? DMARC_PARSE_OKAY
+ : opendmarc_policy_store_from_domain(dmarc_pctx, header_from_sender);
+ if (libdm_status != DMARC_PARSE_OKAY)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failure to store header From: in DMARC: %s, header was '%s'",
+ opendmarc_policy_status_to_str(libdm_status), from_header->text);
+ dmarc_abort = TRUE;
+ }
+ }
+
+/* Skip DMARC if connection is SMTP Auth. Temporarily, admin should
+instead do this in the ACLs. */
+
+if (!dmarc_abort && !sender_host_authenticated)
+ {
+ uschar * dmarc_domain;
+ gstring * dkim_history_buffer = NULL;
+
+ /* Use the envelope sender domain for this part of DMARC */
+
+ spf_sender_domain = expand_string(US"$sender_address_domain");
+
+ {
+ typedef SPF_response_t * (*fn_t)(void);
+ if (spf_mod_info)
+ spf_response_p = ((fn_t *) spf_mod_info->functions)[2](); /* spf_get_response */
+ }
+
+ if (!spf_response_p)
+ {
+ /* No spf data means null envelope sender so generate a domain name
+ from the sender_helo_name */
+
+ if (!spf_sender_domain)
+ {
+ spf_sender_domain = sender_helo_name;
+ log_write(0, LOG_MAIN, "DMARC using synthesized SPF sender domain = %s\n",
+ spf_sender_domain);
+ DEBUG(D_receive)
+ debug_printf_indent("DMARC using synthesized SPF sender domain = %s\n",
+ spf_sender_domain);
+ }
+ dmarc_spf_result = DMARC_POLICY_SPF_OUTCOME_NONE;
+ dmarc_spf_ares_result = ARES_RESULT_UNKNOWN;
+ origin = DMARC_POLICY_SPF_ORIGIN_HELO;
+ spf_human_readable = US"";
+ }
+ else
+ {
+ sr = spf_response_p->result;
+ dmarc_spf_result = sr == SPF_RESULT_NEUTRAL ? DMARC_POLICY_SPF_OUTCOME_NONE :
+ sr == SPF_RESULT_PASS ? DMARC_POLICY_SPF_OUTCOME_PASS :
+ sr == SPF_RESULT_FAIL ? DMARC_POLICY_SPF_OUTCOME_FAIL :
+ sr == SPF_RESULT_SOFTFAIL ? DMARC_POLICY_SPF_OUTCOME_TMPFAIL :
+ DMARC_POLICY_SPF_OUTCOME_NONE;
+ dmarc_spf_ares_result = sr == SPF_RESULT_NEUTRAL ? ARES_RESULT_NEUTRAL :
+ sr == SPF_RESULT_PASS ? ARES_RESULT_PASS :
+ sr == SPF_RESULT_FAIL ? ARES_RESULT_FAIL :
+ sr == SPF_RESULT_SOFTFAIL ? ARES_RESULT_SOFTFAIL :
+ sr == SPF_RESULT_NONE ? ARES_RESULT_NONE :
+ sr == SPF_RESULT_TEMPERROR ? ARES_RESULT_TEMPERROR :
+ sr == SPF_RESULT_PERMERROR ? ARES_RESULT_PERMERROR :
+ ARES_RESULT_UNKNOWN;
+ origin = DMARC_POLICY_SPF_ORIGIN_MAILFROM;
+ spf_human_readable = US spf_response_p->header_comment;
+ DEBUG(D_receive)
+ debug_printf_indent("DMARC using SPF sender domain = %s\n", spf_sender_domain);
+ }
+ if (strcmp( CCS spf_sender_domain, "") == 0)
+ dmarc_abort = TRUE;
+ if (!dmarc_abort)
+ {
+ libdm_status = opendmarc_policy_store_spf(dmarc_pctx, spf_sender_domain,
+ dmarc_spf_result, origin, spf_human_readable);
+ if (libdm_status != DMARC_PARSE_OKAY)
+ log_write(0, LOG_MAIN|LOG_PANIC, "failure to store spf for DMARC: %s",
+ opendmarc_policy_status_to_str(libdm_status));
+ }
+
+ /* Now we cycle through the dkim signature results and put into
+ the opendmarc context, further building the DMARC reply. */
+
+ for(pdkim_signature * sig = dkim_signatures; sig; sig = sig->next)
+ {
+ int dkim_result, dkim_ares_result, vs, ves;
+
+ vs = sig->verify_status & ~PDKIM_VERIFY_POLICY;
+ ves = sig->verify_ext_status;
+ dkim_result = vs == PDKIM_VERIFY_PASS ? DMARC_POLICY_DKIM_OUTCOME_PASS :
+ vs == PDKIM_VERIFY_FAIL ? DMARC_POLICY_DKIM_OUTCOME_FAIL :
+ vs == PDKIM_VERIFY_INVALID ? DMARC_POLICY_DKIM_OUTCOME_TMPFAIL :
+ DMARC_POLICY_DKIM_OUTCOME_NONE;
+ libdm_status = opendmarc_policy_store_dkim(dmarc_pctx, US sig->domain,
+
+/* The opendmarc project broke its API in a way we can't detect easily.
+The EDITME provides a DMARC_API variable */
+#if DMARC_API >= 100400
+ sig->selector,
+#endif
+ dkim_result, US"");
+ DEBUG(D_receive)
+ debug_printf_indent("DMARC adding DKIM sender domain = %s\n", sig->domain);
+ if (libdm_status != DMARC_PARSE_OKAY)
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failure to store dkim (%s) for DMARC: %s",
+ sig->domain, opendmarc_policy_status_to_str(libdm_status));
+
+ dkim_ares_result =
+ vs == PDKIM_VERIFY_PASS ? ARES_RESULT_PASS :
+ vs == PDKIM_VERIFY_FAIL ? ARES_RESULT_FAIL :
+ vs == PDKIM_VERIFY_NONE ? ARES_RESULT_NONE :
+ vs == PDKIM_VERIFY_INVALID ?
+ ves == PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE ? ARES_RESULT_PERMERROR :
+ ves == PDKIM_VERIFY_INVALID_BUFFER_SIZE ? ARES_RESULT_PERMERROR :
+ ves == PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD ? ARES_RESULT_PERMERROR :
+ ves == PDKIM_VERIFY_INVALID_PUBKEY_IMPORT ? ARES_RESULT_PERMERROR :
+ ARES_RESULT_UNKNOWN :
+ ARES_RESULT_UNKNOWN;
+#if DMARC_API >= 100400
+ dkim_history_buffer = string_fmt_append(dkim_history_buffer,
+ "dkim %s %s %d\n", sig->domain, sig->selector, dkim_ares_result);
+#else
+ dkim_history_buffer = string_fmt_append(dkim_history_buffer,
+ "dkim %s %d\n", sig->domain, dkim_ares_result);
+#endif
+ }
+
+ /* Look up DMARC policy record in DNS. We do this explicitly, rather than
+ letting the dmarc library do it with opendmarc_policy_query_dmarc(), so that
+ our dns access path is used for debug tracing and for the testsuite
+ diversion. */
+
+ libdm_status = (rr = dmarc_dns_lookup(header_from_sender))
+ ? opendmarc_policy_store_dmarc(dmarc_pctx, rr, header_from_sender, NULL)
+ : DMARC_DNS_ERROR_NO_RECORD;
+ switch (libdm_status)
+ {
+ case DMARC_DNS_ERROR_NXDOMAIN:
+ case DMARC_DNS_ERROR_NO_RECORD:
+ DEBUG(D_receive)
+ debug_printf_indent("DMARC no record found for %s\n", header_from_sender);
+ has_dmarc_record = FALSE;
+ break;
+ case DMARC_PARSE_OKAY:
+ DEBUG(D_receive)
+ debug_printf_indent("DMARC record found for %s\n", header_from_sender);
+ break;
+ case DMARC_PARSE_ERROR_BAD_VALUE:
+ DEBUG(D_receive)
+ debug_printf_indent("DMARC record parse error for %s\n", header_from_sender);
+ has_dmarc_record = FALSE;
+ break;
+ default:
+ /* everything else, skip dmarc */
+ DEBUG(D_receive)
+ debug_printf_indent("DMARC skipping (%s), unsure what to do with %s",
+ opendmarc_policy_status_to_str(libdm_status),
+ from_header->text);
+ has_dmarc_record = FALSE;
+ break;
+ }
+
+ /* Store the policy string in an expandable variable. */
+
+ libdm_status = opendmarc_policy_fetch_p(dmarc_pctx, &tmp_ans);
+ for (c = 0; dmarc_policy_description[c].name; c++)
+ if (tmp_ans == dmarc_policy_description[c].value)
+ {
+ dmarc_domain_policy = string_sprintf("%s",dmarc_policy_description[c].name);
+ break;
+ }
+
+ /* Can't use exim's string manipulation functions so allocate memory
+ for libopendmarc using its max hostname length definition. */
+
+ dmarc_domain = store_get(DMARC_MAXHOSTNAMELEN, GET_TAINTED);
+ libdm_status = opendmarc_policy_fetch_utilized_domain(dmarc_pctx,
+ dmarc_domain, DMARC_MAXHOSTNAMELEN-1);
+ store_release_above(dmarc_domain + Ustrlen(dmarc_domain)+1);
+ dmarc_used_domain = dmarc_domain;
+
+ if (libdm_status != DMARC_PARSE_OKAY)
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failure to read domainname used for DMARC lookup: %s",
+ opendmarc_policy_status_to_str(libdm_status));
+
+ dmarc_policy = libdm_status = opendmarc_get_policy_to_enforce(dmarc_pctx);
+ switch(libdm_status)
+ {
+ case DMARC_POLICY_ABSENT: /* No DMARC record found */
+ dmarc_status = US"norecord";
+ dmarc_pass_fail = US"none";
+ dmarc_status_text = US"No DMARC record";
+ action = DMARC_RESULT_ACCEPT;
+ break;
+ case DMARC_FROM_DOMAIN_ABSENT: /* No From: domain */
+ dmarc_status = US"nofrom";
+ dmarc_pass_fail = US"temperror";
+ dmarc_status_text = US"No From: domain found";
+ action = DMARC_RESULT_ACCEPT;
+ break;
+ case DMARC_POLICY_NONE: /* Accept and report */
+ dmarc_status = US"none";
+ dmarc_pass_fail = US"none";
+ dmarc_status_text = US"None, Accept";
+ action = DMARC_RESULT_ACCEPT;
+ break;
+ case DMARC_POLICY_PASS: /* Explicit accept */
+ dmarc_status = US"accept";
+ dmarc_pass_fail = US"pass";
+ dmarc_status_text = US"Accept";
+ action = DMARC_RESULT_ACCEPT;
+ break;
+ case DMARC_POLICY_REJECT: /* Explicit reject */
+ dmarc_status = US"reject";
+ dmarc_pass_fail = US"fail";
+ dmarc_status_text = US"Reject";
+ action = DMARC_RESULT_REJECT;
+ break;
+ case DMARC_POLICY_QUARANTINE: /* Explicit quarantine */
+ dmarc_status = US"quarantine";
+ dmarc_pass_fail = US"fail";
+ dmarc_status_text = US"Quarantine";
+ action = DMARC_RESULT_QUARANTINE;
+ break;
+ default:
+ dmarc_status = US"temperror";
+ dmarc_pass_fail = US"temperror";
+ dmarc_status_text = US"Internal Policy Error";
+ action = DMARC_RESULT_TEMPFAIL;
+ break;
+ }
+
+ libdm_status = opendmarc_policy_fetch_alignment(dmarc_pctx, &da, &sa);
+ if (libdm_status != DMARC_PARSE_OKAY)
+ log_write(0, LOG_MAIN|LOG_PANIC, "failure to read DMARC alignment: %s",
+ opendmarc_policy_status_to_str(libdm_status));
+
+ if (has_dmarc_record)
+ {
+ log_write(0, LOG_MAIN, "DMARC results: spf_domain=%s dmarc_domain=%s "
+ "spf_align=%s dkim_align=%s enforcement='%s'",
+ spf_sender_domain, dmarc_used_domain,
+ sa==DMARC_POLICY_SPF_ALIGNMENT_PASS ?"yes":"no",
+ da==DMARC_POLICY_DKIM_ALIGNMENT_PASS ?"yes":"no",
+ dmarc_status_text);
+ history_file_status = dmarc_write_history_file(dkim_history_buffer);
+ /* Now get the forensic reporting addresses, if any */
+ ruf = opendmarc_policy_fetch_ruf(dmarc_pctx, NULL, 0, 1);
+ dmarc_send_forensic_report(ruf);
+ }
+ }
+
+/* shut down libopendmarc */
+if (dmarc_pctx)
+ (void) opendmarc_policy_connect_shutdown(dmarc_pctx);
+if (!f.dmarc_disable_verify)
+ (void) opendmarc_policy_library_shutdown(&dmarc_ctx);
+
+return OK;
+}
+
+static uschar *
+dmarc_exim_expand_defaults(int what)
+{
+if (what == DMARC_VERIFY_STATUS)
+ return f.dmarc_disable_verify ? US"off" : US"none";
+return US"";
+}
+
+static uschar *
+dmarc_exim_expand_query(int what)
+{
+if (f.dmarc_disable_verify || !dmarc_pctx)
+ return dmarc_exim_expand_defaults(what);
+
+if (what == DMARC_VERIFY_STATUS)
+ return dmarc_status;
+return US"";
+}
+
+
+static gstring *
+authres_dmarc(gstring * g)
+{
+if (f.dmarc_has_been_checked)
+ {
+ int start = 0; /* Compiler quietening */
+ DEBUG(D_acl) start = gstring_length(g);
+ g = string_append(g, 2, US";\n\tdmarc=", dmarc_pass_fail);
+ if (header_from_sender)
+ g = string_append(g, 2, US" header.from=", header_from_sender);
+ DEBUG(D_acl) debug_printf("DMARC:\tauthres '%.*s'\n",
+ gstring_length(g) - start - 3, g->s + start + 3);
+ }
+else
+ DEBUG(D_acl) debug_printf("DMARC:\tno authres\n");
+return g;
+}
+
+/******************************************************************************/
+/* Module API */
+
+static optionlist dmarc_options[] = {
+ { "dmarc_forensic_sender", opt_stringptr, {&dmarc_forensic_sender} },
+ { "dmarc_history_file", opt_stringptr, {&dmarc_history_file} },
+ { "dmarc_tld_file", opt_stringptr, {&dmarc_tld_file} },
+};
+
+static void * dmarc_functions[] = {
+ dmarc_process,
+ dmarc_exim_expand_query,
+ authres_dmarc,
+ dmarc_store_data,
+};
+
+/* dmarc_forensic_sender is provided for visibility of the the option setting
+by moan_send_message. We do not document it as a config-visible $variable.
+We could provide it via a function but there's little advantage. */
+
+static var_entry dmarc_variables[] = {
+ { "dmarc_domain_policy", vtype_stringptr, &dmarc_domain_policy },
+ { "dmarc_forensic_sender", vtype_stringptr, &dmarc_forensic_sender },
+ { "dmarc_status", vtype_stringptr, &dmarc_status },
+ { "dmarc_status_text", vtype_stringptr, &dmarc_status_text },
+ { "dmarc_used_domain", vtype_stringptr, &dmarc_used_domain },
+};
+
+misc_module_info dmarc_module_info =
+{
+ .name = US"dmarc",
+# if SUPPORT_SPF==2
+ .dyn_magic = MISC_MODULE_MAGIC,
+# endif
+ .init = dmarc_init,
+ .lib_vers_report = dmarc_version_report,
+ .smtp_reset = dmarc_smtp_reset,
+ .msg_init = dmarc_msg_init,
+
+ .options = dmarc_options,
+ .options_count = nelem(dmarc_options),
+
+ .functions = dmarc_functions,
+ .functions_count = nelem(dmarc_functions),
+
+ .variables = dmarc_variables,
+ .variables_count = nelem(dmarc_variables),
+};
+
+# endif /* SUPPORT_SPF */
+#endif /* SUPPORT_DMARC */
+/* vi: aw ai sw=2
+ */
git://git.exim.org / exim.git / commitdiff