* Exim - an Internet mail transport agent *
*************************************************/
+/* Copyright (c) The Exim Maintainers 2020 - 2023 */
/* Copyright (c) University of Cambridge, 1995 - 2018 */
/* See the file NOTICE for conditions of use and distribution. */
+/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Code for DKIM support. Other DKIM relevant code is in
receive.c, transport.c and transports/smtp.c */
dns_answer * dnsa = store_get_dns_answer();
dns_scan dnss;
rmark reset_point = store_mark();
-gstring * g = NULL;
+gstring * g = string_get_tainted(256, GET_TAINTED);
lookup_dnssec_authenticated = NULL;
if (dns_lookup(dnsa, name, T_TXT, NULL) != DNS_SUCCEED)
- return NULL; /*XXX better error detail? logging? */
+ goto bad;
/* Search for TXT record */
rr;
rr = dns_next_rr(dnsa, &dnss, RESET_NEXT))
if (rr->type == T_TXT)
- {
- int rr_offset = 0;
-
- /* Copy record content to the answer buffer */
-
- while (rr_offset < rr->size)
+ { /* Copy record content to the answer buffer */
+ for (int rr_offset = 0; rr_offset < rr->size; )
{
uschar len = rr->data[rr_offset++];
rr_offset += len;
}
- /* check if this looks like a DKIM record */
+ /* Check if this looks like a DKIM record */
if (Ustrncmp(g->s, "v=", 2) != 0 || strncasecmp(CS g->s, "v=dkim", 6) == 0)
{
+ store_free_dns_answer(dnsa);
gstring_release_unused(g);
return string_from_gstring(g);
}
- if (g) g->ptr = 0; /* overwrite previous record */
+ gstring_reset(g); /* overwrite previous record */
}
bad:
store_reset(reset_point);
+store_free_dns_answer(dnsa);
return NULL; /*XXX better error detail? logging? */
}
{
dkim_exim_init();
-/* There is a store-reset between header & body reception
-so cannot use the main pool. Any allocs done by Exim
-memory-handling must use the perm pool. */
+/* There is a store-reset between header & body reception for the main pool
+(actually, after every header line) so cannot use that as we need the data we
+store per-header, during header processing, at the end of body reception
+for evaluating the signature. Any allocs done for dkim verify
+memory-handling must use a different pool. We use a separate one that we
+can reset per message. */
dkim_verify_oldpool = store_pool;
-store_pool = POOL_PERM;
+store_pool = POOL_MESSAGE;
/* Free previous context if there is one */
dkim_collect_input = dkim_verify_ctx ? DKIM_MAX_SIGNATURES : 0;
dkim_collect_error = NULL;
-/* Start feed up with any cached data */
-receive_get_cache();
+/* Start feed up with any cached data, but limited to message data */
+receive_get_cache(chunking_state == CHUNKING_LAST
+ ? chunking_data_left : GETC_BUFFER_UNLIMITED);
store_pool = dkim_verify_oldpool;
}
+/* Submit a chunk of data for verification input.
+Only use the data when the feed is activated. */
void
dkim_exim_verify_feed(uschar * data, int len)
{
int rc;
-store_pool = POOL_PERM;
+store_pool = POOL_MESSAGE;
if ( dkim_collect_input
&& (rc = pdkim_feed(dkim_verify_ctx, data, len)) != PDKIM_OK)
{
break;
}
-log_write(0, LOG_MAIN, "%s", string_from_gstring(logmsg));
+log_write(0, LOG_MAIN, "%Y", logmsg);
return;
}
gstring * g = NULL;
const uschar * errstr = NULL;
-store_pool = POOL_PERM;
+store_pool = POOL_MESSAGE;
/* Delete eventual previous signature chain */
store_pool = POOL_MAIN;
+GET_OPTION("dkim_domain");
if ((s = dkim->dkim_domain) && !(dkim_domain = expand_cstring(s)))
/* expansion error, do not send message. */
{ errwhen = US"dkim_domain"; goto expand_bad; }
/* Set $dkim_selector expansion variable to each selector in list,
for this domain. */
+ GET_OPTION("dkim_selector");
if (!(dkim_sel = expand_string(dkim->dkim_selector)))
{ errwhen = US"dkim_selector"; goto expand_bad; }
/* Get canonicalization to use */
+ GET_OPTION("dkim_canon");
dkim_canon_expanded = dkim->dkim_canon
? expand_string(dkim->dkim_canon) : US"relaxed";
if (!dkim_canon_expanded) /* expansion error, do not send message. */
pdkim_canon = PDKIM_CANON_RELAXED;
}
+ GET_OPTION("dkim_sign_headers");
if ( dkim->dkim_sign_headers
&& !(dkim_sign_headers_expanded = expand_string(dkim->dkim_sign_headers)))
{ errwhen = US"dkim_sign_header"; goto expand_bad; }
/* Get private key to use. */
+ GET_OPTION("dkim_private_key");
if (!(dkim_private_key_expanded = expand_string(dkim->dkim_private_key)))
{ errwhen = US"dkim_private_key"; goto expand_bad; }
expand_file_big_buffer(dkim_private_key_expanded)))
goto bad;
+ GET_OPTION("dkim_hash");
if (!(dkim_hash_expanded = expand_string(dkim->dkim_hash)))
{ errwhen = US"dkim_hash"; goto expand_bad; }
+ GET_OPTION("dkim_identity");
if (dkim->dkim_identity)
if (!(dkim_identity_expanded = expand_string(dkim->dkim_identity)))
{ errwhen = US"dkim_identity"; goto expand_bad; }
else if (!*dkim_identity_expanded)
dkim_identity_expanded = NULL;
+ GET_OPTION("dkim_timestamps");
if (dkim->dkim_timestamps)
if (!(dkim_timestamps_expanded = expand_string(dkim->dkim_timestamps)))
{ errwhen = US"dkim_timestamps"; goto expand_bad; }
else
- xval = (tval = (unsigned long) time(NULL))
- + strtoul(CCS dkim_timestamps_expanded, NULL, 10);
+ {
+ tval = (unsigned long) time(NULL);
+ xval = strtoul(CCS dkim_timestamps_expanded, NULL, 10);
+ if (xval > 0)
+ xval += tval;
+ }
if (!(sig = pdkim_init_sign(&dkim_sign_ctx, dkim_signing_domain,
dkim_signing_selector,
if (!pdkim_set_sig_bodyhash(&dkim_sign_ctx, sig))
goto bad;
+ dkim_signing_record = string_append_listele(dkim_signing_record, ':', dkim_signing_domain);
+ dkim_signing_record = string_append_listele(dkim_signing_record, ':', dkim_signing_selector);
+
if (!dkim_sign_ctx.sig) /* link sig to context chain */
dkim_sign_ctx.sig = sig;
else
{
int start = 0; /* compiler quietening */
-DEBUG(D_acl) start = g->ptr;
+DEBUG(D_acl) start = gstring_length(g);
for (pdkim_signature * sig = dkim_signatures; sig; sig = sig->next)
{
}
DEBUG(D_acl)
- if (g->ptr == start)
- debug_printf("DKIM: no authres\n");
+ if (gstring_length(g) == start)
+ debug_printf("DKIM:\tno authres\n");
else
- debug_printf("DKIM: authres '%.*s'\n", g->ptr - start - 3, g->s + start + 3);
+ debug_printf("DKIM:\tauthres '%.*s'\n", g->ptr - start - 3, g->s + start + 3);
return g;
}
git://git.exim.org / exim.git / blobdiff