X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/31f5b3492bde6a055c0c349a3d46718bd5a7e4f0..HEAD:/src/src/dmarc.c diff --git a/src/src/dmarc.c b/src/src/dmarc.c index 750f9197f..28fce0624 100644 --- a/src/src/dmarc.c +++ b/src/src/dmarc.c @@ -2,9 +2,10 @@ * Exim - an Internet mail transport agent * *************************************************/ /* DMARC support. + Copyright (c) The Exim Maintainers 2019 - 2024 Copyright (c) Todd Lyons 2012 - 2014 - Copyright (c) The Exim Maintainers 2019 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. */ @@ -36,7 +37,6 @@ uschar *spf_sender_domain = NULL; uschar *spf_human_readable = NULL; u_char *header_from_sender = NULL; int history_file_status = DMARC_HIST_OK; -uschar *dkim_history_buffer= NULL; typedef struct dmarc_exim_p { uschar *name; @@ -53,14 +53,12 @@ static dmarc_exim_p dmarc_policy_description[] = { }; -void -dmarc_version_report(FILE *f) +gstring * +dmarc_version_report(gstring * g) { -const char *implementation, *version; - -fprintf(f, "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); +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); } @@ -93,13 +91,14 @@ messages on the same SMTP connection (that come from the same host with the same HELO string) */ int -dmarc_init() +dmarc_init(void) { int *netmask = NULL; /* Ignored */ int is_ipv6 = 0; /* Set some sane defaults. Also clears previous results when - * multiple messages in one connection. */ +multiple messages in one connection. */ + dmarc_pctx = NULL; dmarc_status = US"none"; dmarc_abort = FALSE; @@ -125,7 +124,7 @@ if (libdm_status != DMARC_PARSE_OKAY) } if (!dmarc_tld_file || !*dmarc_tld_file) { - DEBUG(D_receive) debug_printf("DMARC: no dmarc_tld_file\n"); + 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)) @@ -136,7 +135,7 @@ else if (opendmarc_tld_read_file(CS dmarc_tld_file, NULL, NULL, NULL)) } if (!sender_host_address) { - DEBUG(D_receive) debug_printf("DMARC: no sender_host_address\n"); + DEBUG(D_receive) debug_printf_indent("DMARC: no sender_host_address\n"); dmarc_abort = TRUE; } /* This catches locally originated email and startup errors above. */ @@ -155,11 +154,12 @@ return OK; } -/* dmarc_store_data stores the header data so that subsequent -dmarc_process can access the data */ +/* 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. */ int -dmarc_store_data(header_line *hdr) +dmarc_store_data(header_line * hdr) { /* No debug output because would change every test debug output */ if (!f.dmarc_disable_verify) @@ -169,7 +169,7 @@ return OK; static void -dmarc_send_forensic_report(u_char **ruf) +dmarc_send_forensic_report(u_char ** ruf) { uschar *recipient, *save_sender; BOOL send_status = FALSE; @@ -204,7 +204,7 @@ if ( dmarc_policy == DMARC_POLICY_REJECT && action == DMARC_RESULT_REJECT /* Move to first character past the colon */ recipient += 7; DEBUG(D_receive) - debug_printf("DMARC forensic report to %s%s\n", recipient, + 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; @@ -232,8 +232,9 @@ if (rc == DNS_SUCCEED) 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 string_copyn_taint(US rr->data, rr->size, TRUE); + return record; } store_free_dns_answer(dnsa); return NULL; @@ -241,81 +242,96 @@ return NULL; static int -dmarc_write_history_file() +dmarc_write_history_file(const gstring * dkim_history_buffer) { -int history_file_fd; +int history_file_fd = 0; ssize_t written_len; int tmp_ans; -u_char **rua; /* aggregate report addressees */ -uschar *history_buffer = NULL; +u_char ** rua; /* aggregate report addressees */ +gstring * g; if (!dmarc_history_file) { - DEBUG(D_receive) debug_printf("DMARC history file not set\n"); + DEBUG(D_receive) debug_printf_indent("DMARC history file not set\n"); return DMARC_HIST_DISABLED; } -history_file_fd = log_create_as_exim(dmarc_history_file); - -if (history_file_fd < 0) +if (!host_checking) { - log_write(0, LOG_MAIN|LOG_PANIC, "failure to create DMARC history file: %s", - dmarc_history_file); - return DMARC_HIST_FILE_ERR; + 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 */ -history_buffer = string_sprintf( +/* 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) - history_buffer = string_sprintf("%sspf %d\n", history_buffer, dmarc_spf_ares_result); - /* history_buffer = string_sprintf("%sspf -1\n", history_buffer); */ + g = string_fmt_append(g, "spf %d\n", dmarc_spf_ares_result); -history_buffer = string_sprintf( - "%s%spdomain %s\npolicy %d\n", - history_buffer, dkim_history_buffer, dmarc_used_domain, dmarc_policy); +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++) - history_buffer = string_sprintf("%srua %s\n", history_buffer, rua[tmp_ans]); + g = string_fmt_append(g, "rua %s\n", rua[tmp_ans]); else - history_buffer = string_sprintf("%srua -\n", history_buffer); + g = string_catn(g, US"rua -\n", 6); opendmarc_policy_fetch_pct(dmarc_pctx, &tmp_ans); -history_buffer = string_sprintf("%spct %d\n", history_buffer, tmp_ans); +g = string_fmt_append(g, "pct %d\n", tmp_ans); opendmarc_policy_fetch_adkim(dmarc_pctx, &tmp_ans); -history_buffer = string_sprintf("%sadkim %d\n", history_buffer, tmp_ans); +g = string_fmt_append(g, "adkim %d\n", tmp_ans); opendmarc_policy_fetch_aspf(dmarc_pctx, &tmp_ans); -history_buffer = string_sprintf("%saspf %d\n", history_buffer, tmp_ans); +g = string_fmt_append(g, "aspf %d\n", tmp_ans); opendmarc_policy_fetch_p(dmarc_pctx, &tmp_ans); -history_buffer = string_sprintf("%sp %d\n", history_buffer, tmp_ans); +g = string_fmt_append(g, "p %d\n", tmp_ans); opendmarc_policy_fetch_sp(dmarc_pctx, &tmp_ans); -history_buffer = string_sprintf("%ssp %d\n", history_buffer, 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); -history_buffer = string_sprintf( - "%salign_dkim %d\nalign_spf %d\naction %d\n", - history_buffer, 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("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); + 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--; } -else + +if (!host_checking) { written_len = write_to_fd_buf(history_file_fd, - history_buffer, - Ustrlen(history_buffer)); + g->s, + gstring_length(g)); if (written_len == 0) { log_write(0, LOG_MAIN|LOG_PANIC, "failure to write to DMARC history file: %s", @@ -330,10 +346,11 @@ 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. */ +strings and evaluates the condition outcome. +Called for the first ACL dmarc= condition. */ int -dmarc_process() +dmarc_process(void) { int sr, origin; /* used in SPF section */ int dmarc_spf_result = 0; /* stores spf into dmarc conn ctx */ @@ -341,21 +358,21 @@ 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 */ +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 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("DMARC: no From: header\n"); + DEBUG(D_receive) debug_printf_indent("DMARC: no From: header\n"); dmarc_abort = TRUE; } else if (!dmarc_abort) @@ -374,7 +391,8 @@ else if (!dmarc_abort) *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. */ + 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 @@ -390,24 +408,28 @@ else if (!dmarc_abort) } /* Skip DMARC if connection is SMTP Auth. Temporarily, admin should - * instead do this in the ACLs. */ +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"); if (!spf_response) { /* No spf data means null envelope sender so generate a domain name - * from the sender_helo_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("DMARC using synthesized SPF sender domain = %s\n", + debug_printf_indent("DMARC using synthesized SPF sender domain = %s\n", spf_sender_domain); } dmarc_spf_result = DMARC_POLICY_SPF_OUTCOME_NONE; @@ -434,7 +456,7 @@ if (!dmarc_abort && !sender_host_authenticated) origin = DMARC_POLICY_SPF_ORIGIN_MAILFROM; spf_human_readable = US spf_response->header_comment; DEBUG(D_receive) - debug_printf("DMARC using SPF sender domain = %s\n", spf_sender_domain); + debug_printf_indent("DMARC using SPF sender domain = %s\n", spf_sender_domain); } if (strcmp( CCS spf_sender_domain, "") == 0) dmarc_abort = TRUE; @@ -448,9 +470,9 @@ if (!dmarc_abort && !sender_host_authenticated) } /* Now we cycle through the dkim signature results and put into - * the opendmarc context, further building the DMARC reply. */ - dkim_history_buffer = US""; - while (sig) + 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; @@ -461,9 +483,15 @@ if (!dmarc_abort && !sender_host_authenticated) 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); + 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", @@ -480,9 +508,13 @@ if (!dmarc_abort && !sender_host_authenticated) ves == PDKIM_VERIFY_INVALID_PUBKEY_IMPORT ? ARES_RESULT_PERMERROR : ARES_RESULT_UNKNOWN : ARES_RESULT_UNKNOWN; - dkim_history_buffer = string_sprintf("%sdkim %s %d\n", dkim_history_buffer, - sig->domain, dkim_ares_result); - sig = sig->next; +#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 @@ -498,28 +530,29 @@ if (!dmarc_abort && !sender_host_authenticated) case DMARC_DNS_ERROR_NXDOMAIN: case DMARC_DNS_ERROR_NO_RECORD: DEBUG(D_receive) - debug_printf("DMARC no record found for %s\n", header_from_sender); + 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("DMARC record found for %s\n", header_from_sender); + debug_printf_indent("DMARC record found for %s\n", header_from_sender); break; case DMARC_PARSE_ERROR_BAD_VALUE: DEBUG(D_receive) - debug_printf("DMARC record parse error for %s\n", header_from_sender); + 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("DMARC skipping (%d), unsure what to do with %s", - libdm_status, from_header->text); + 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. */ + /* 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++) @@ -532,7 +565,7 @@ if (!dmarc_abort && !sender_host_authenticated) /* 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, TRUE); + 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); @@ -603,7 +636,7 @@ if (!dmarc_abort && !sender_host_authenticated) 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(); + 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); @@ -644,10 +677,16 @@ 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; }