/*************************************************
* Exim - an Internet mail transport agent *
*************************************************/
-/* Experimental DMARC support.
+/* DMARC support.
+ Copyright (c) The Exim Maintainers 2019 - 2022
Copyright (c) Todd Lyons <tlyons@exim.org> 2012 - 2014
License: GPL */
/* Code for calling dmarc checks via libopendmarc. Called from acl.c. */
#include "exim.h"
-#ifdef EXPERIMENTAL_DMARC
+#ifdef SUPPORT_DMARC
# if !defined SUPPORT_SPF
# error SPF must also be enabled for DMARC
# elif defined DISABLE_DKIM
{ US"reject", DMARC_RECORD_P_REJECT },
{ NULL, 0 }
};
+
+
+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. */
+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 == NULL)
+if (!eblock)
eblock = eb;
else
{
/* Find the end of the eblock struct and point it at eb */
error_block *tmp = eblock;
- while(tmp->next != NULL)
+ while(tmp->next)
tmp = tmp->next;
tmp->next = eb;
}
}
/* dmarc_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) */
+messages on the same SMTP connection (that come from the
+same host with the same HELO string) */
int
dmarc_init()
opendmarc_policy_status_to_str(libdm_status));
dmarc_abort = TRUE;
}
-if (!dmarc_tld_file)
+if (!dmarc_tld_file || !*dmarc_tld_file)
{
DEBUG(D_receive) debug_printf("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: %d",
- dmarc_tld_file, errno);
+ 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)
}
}
+
+/* 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()
+{
+int history_file_fd;
+ssize_t written_len;
+int tmp_ans;
+u_char **rua; /* aggregate report addressees */
+uschar *history_buffer = NULL;
+
+if (!dmarc_history_file)
+ {
+ DEBUG(D_receive) debug_printf("DMARC history file not set\n");
+ return DMARC_HIST_DISABLED;
+ }
+history_file_fd = log_open_as_exim(dmarc_history_file);
+
+if (history_file_fd < 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "failure to create DMARC history file: %s",
+ dmarc_history_file);
+ return DMARC_HIST_FILE_ERR;
+ }
+
+/* Generate the contents of the history file */
+history_buffer = string_sprintf(
+ "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)
+ history_buffer = string_sprintf("%sspf %d\n", history_buffer, dmarc_spf_ares_result);
+ /* history_buffer = string_sprintf("%sspf -1\n", history_buffer); */
+
+history_buffer = string_sprintf(
+ "%s%spdomain %s\npolicy %d\n",
+ history_buffer, dkim_history_buffer, 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++)
+ history_buffer = string_sprintf("%srua %s\n", history_buffer, rua[tmp_ans]);
+else
+ history_buffer = string_sprintf("%srua -\n", history_buffer);
+
+opendmarc_policy_fetch_pct(dmarc_pctx, &tmp_ans);
+history_buffer = string_sprintf("%spct %d\n", history_buffer, tmp_ans);
+
+opendmarc_policy_fetch_adkim(dmarc_pctx, &tmp_ans);
+history_buffer = string_sprintf("%sadkim %d\n", history_buffer, tmp_ans);
+
+opendmarc_policy_fetch_aspf(dmarc_pctx, &tmp_ans);
+history_buffer = string_sprintf("%saspf %d\n", history_buffer, tmp_ans);
+
+opendmarc_policy_fetch_p(dmarc_pctx, &tmp_ans);
+history_buffer = string_sprintf("%sp %d\n", history_buffer, tmp_ans);
+
+opendmarc_policy_fetch_sp(dmarc_pctx, &tmp_ans);
+history_buffer = string_sprintf("%ssp %d\n", history_buffer, tmp_ans);
+
+history_buffer = string_sprintf(
+ "%salign_dkim %d\nalign_spf %d\naction %d\n",
+ history_buffer, da, sa, action);
+
+/* Write the contents to the history file */
+DEBUG(D_receive)
+ debug_printf("DMARC logging history data for opendmarc reporting%s\n",
+ (host_checking || f.running_in_test_harness) ? " (not really)" : "");
+if (host_checking || f.running_in_test_harness)
+ {
+ DEBUG(D_receive)
+ debug_printf("DMARC history data for debugging:\n%s", history_buffer);
+ }
+else
+ {
+ written_len = write_to_fd_buf(history_file_fd,
+ history_buffer,
+ Ustrlen(history_buffer));
+ 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. */
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 */
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,
- dkim_result, US"");
+/* 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("DMARC adding DKIM sender domain = %s\n", sig->domain);
if (libdm_status != DMARC_PARSE_OKAY)
sig->domain, dkim_ares_result);
sig = sig->next;
}
- libdm_status = opendmarc_policy_query_dmarc(dmarc_pctx, US"");
+
+ /* 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:
/* Can't use exim's string manipulation functions so allocate memory
for libopendmarc using its max hostname length definition. */
- dmarc_domain = US calloc(DMARC_MAXHOSTNAMELEN, sizeof(uschar));
+ dmarc_domain = store_get(DMARC_MAXHOSTNAMELEN, GET_TAINTED);
libdm_status = opendmarc_policy_fetch_utilized_domain(dmarc_pctx,
dmarc_domain, DMARC_MAXHOSTNAMELEN-1);
- dmarc_used_domain = string_copy(dmarc_domain);
- free(dmarc_domain);
+ 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,
return OK;
}
-static int
-dmarc_write_history_file()
-{
-int history_file_fd;
-ssize_t written_len;
-int tmp_ans;
-u_char **rua; /* aggregate report addressees */
-uschar *history_buffer = NULL;
-
-if (!dmarc_history_file)
- {
- DEBUG(D_receive) debug_printf("DMARC history file not set\n");
- return DMARC_HIST_DISABLED;
- }
-history_file_fd = log_create(dmarc_history_file);
-
-if (history_file_fd < 0)
- {
- log_write(0, LOG_MAIN|LOG_PANIC, "failure to create DMARC history file: %s",
- dmarc_history_file);
- return DMARC_HIST_FILE_ERR;
- }
-
-/* Generate the contents of the history file */
-history_buffer = string_sprintf(
- "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)
- history_buffer = string_sprintf("%sspf %d\n", history_buffer, dmarc_spf_ares_result);
- /* history_buffer = string_sprintf("%sspf -1\n", history_buffer); */
-
-history_buffer = string_sprintf(
- "%s%spdomain %s\npolicy %d\n",
- history_buffer, dkim_history_buffer, 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++)
- history_buffer = string_sprintf("%srua %s\n", history_buffer, rua[tmp_ans]);
-else
- history_buffer = string_sprintf("%srua -\n", history_buffer);
-
-opendmarc_policy_fetch_pct(dmarc_pctx, &tmp_ans);
-history_buffer = string_sprintf("%spct %d\n", history_buffer, tmp_ans);
-
-opendmarc_policy_fetch_adkim(dmarc_pctx, &tmp_ans);
-history_buffer = string_sprintf("%sadkim %d\n", history_buffer, tmp_ans);
-
-opendmarc_policy_fetch_aspf(dmarc_pctx, &tmp_ans);
-history_buffer = string_sprintf("%saspf %d\n", history_buffer, tmp_ans);
-
-opendmarc_policy_fetch_p(dmarc_pctx, &tmp_ans);
-history_buffer = string_sprintf("%sp %d\n", history_buffer, tmp_ans);
-
-opendmarc_policy_fetch_sp(dmarc_pctx, &tmp_ans);
-history_buffer = string_sprintf("%ssp %d\n", history_buffer, tmp_ans);
-
-history_buffer = string_sprintf(
- "%salign_dkim %d\nalign_spf %d\naction %d\n",
- history_buffer, da, sa, action);
-
-/* Write the contents to the history file */
-DEBUG(D_receive)
- debug_printf("DMARC logging history data for opendmarc reporting%s\n",
- (host_checking || f.running_in_test_harness) ? " (not really)" : "");
-if (host_checking || f.running_in_test_harness)
- {
- DEBUG(D_receive)
- debug_printf("DMARC history data for debugging:\n%s", history_buffer);
- }
-else
- {
- written_len = write_to_fd_buf(history_file_fd,
- history_buffer,
- Ustrlen(history_buffer));
- 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;
-}
-
-
uschar *
dmarc_exim_expand_query(int what)
{
}
# endif /* SUPPORT_SPF */
-#endif /* EXPERIMENTAL_DMARC */
+#endif /* SUPPORT_DMARC */
/* vi: aw ai sw=2
*/
git://git.exim.org / exim.git / blobdiff