Commit Graph

558 Commits

Author SHA1 Message Date
Werner Koch 1009e4e5f7
dirmngr: Make building with a TLS library mandatory
* configure.ac: Do not build dirmngr if no TLS is available.
* dirmngr/http.c: Remove all uses of the USE_TLS macro.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-11-26 12:02:27 +01:00
Werner Koch d9c7935188
dirmngr,gpg: Better diagnostic in case of bad TLS certificates.
* doc/DETAILS: Specify new status code "NOTE".
* dirmngr/ks-engine-http.c (ks_http_fetch): Print a NOTE status for a
bad TLS certificate.
* g10/call-dirmngr.c (ks_status_cb): Detect this status.
--

For example a

  gpg -v --locate-external-keys dd9jn@posteo.net

now yields

  gpg: Note: server uses an invalid certificate
  gpg: (further info: bad cert for 'posteo.net': \
                      Hostname does not match the certificate)
  gpg: error retrieving 'dd9jn@posteo.net' via WKD: Wrong name
  gpg: error reading key: Wrong name

(without -v the "further info" line is not shown).  Note that even
after years Posteo is not able to provide a valid certificate for
their .net addresses.  Anyway, this help to show the feature.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-11-18 18:26:55 +01:00
Werner Koch ae9acb8745
dirmngr: Forward http redirect warnings to gpg.
* dirmngr/http.c: Include dirmngr-status.h
(http_prepare_redirect): Emit WARNING status lines for redirection
problems.
* dirmngr/http.h: Include fwddecl.h.
(struct http_redir_info_s): Add field ctrl.
* dirmngr/ks-engine-hkp.c (send_request): Set it.
* dirmngr/ks-engine-http.c (ks_http_fetch): Set it.
* g10/call-dirmngr.c (ks_status_cb): Detect the two new warnings.
--

This should make it easier to diagnose problems with bad WKD servers.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-11-18 18:24:02 +01:00
Werner Koch 5967cfcc71
dirmngr: Fixed typo in recently added diagnostic.
--
2019-11-18 18:24:01 +01:00
Werner Koch 12def3a84e
dirmngr: Use IPv4 or IPv6 interface only if available.
* dirmngr/dns-stuff.c (cached_inet_support): New variable.
(dns_stuff_housekeeping): New.
(check_inet_support): New.
* dirmngr/http.c (connect_server): Use only detected interfaces.
* dirmngr/dirmngr.c (housekeeping_thread): Flush the new cache.
--

This currently works only for Windows but that is where users really
ran into problems.  The old workaround was to configure disable-ipv4
or disable-ipv6.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-11-12 20:35:12 +01:00
Andre Heinecke 40daa0bc0b
dirmngr: Tune down err on missing ldapservers file
* dirmngr/dirmngr.c (parse_ldapservers_file): Tune down error
in case no such file exists.

--
This is hardly an error because by default such a file
does not exist. This caused trouble in support because
people think "Oh the system prints an error".

GnuPG-Bug-Id: T3539
2019-11-12 10:38:41 +01:00
Werner Koch 4c295646ba
dirmngr: Remove cruft from dirmngr_ldap
* configure.ac (USE_LDAPWRAPPER): Remove ac_define and conditional.
* dirmngr/Makefile.am: Remove USE_LDAPWRAPPER and considere true.
* dirmngr/ldap-wrapper-ce.c: Remove.
* dirmngr/ldap-wrapper.c: Remove USE_LDAPWRAPPER stuff. Minor chnages
to debug output.
* dirmngr/dirmngr_ldap.c: Remove USE_LDAPWRAPPER stuff.  Remove
my_ldap macros.
(fetch_ldap) [W32]: Use ldap_sslinit.
--

Note that the ldap_sslinit stuff for Windows has not been tested.

This patch removes the whole wrapper-but-linked business because we do
not need it anymore.  WindowsCE for which we used it is pretty dead.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-11-11 20:49:04 +01:00
Werner Koch eebd43d5b6
dirmngr: Rename an enum value for clarity.
* dirmngr/ldapserver.h: Rename LDAPSERVER_OPT.
--

Using _OPT is not good because it does not describe for what this
configuration group is used.  _SESSION immediately shows the purpose.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-11-11 09:45:01 +01:00
Werner Koch 6e1c99bc39
gpgsm: Allow sepcification of ldaps servers.
* sm/gpgsm.h (struct keyserver_spec): Add field use_ldaps.
* sm/gpgsm.c (parse_keyserver_line): Parse flags.
* sm/call-dirmngr.c (prepare_dirmngr): Send ldaps flag to the dirmngr.

* dirmngr/dirmngr.h (struct ldap_server_s): Add field use_ldaps.
* dirmngr/ldapserver.c (ldapserver_parse_one): Parse flags.
* dirmngr/ldap.c (start_cert_fetch_ldap): Call wrapper with --tls.

* dirmngr/dirmngr_ldap.c: New option --tls.
(fetch_ldap): Make use of that option.
--

There was no way to specify an LDAPS server in
dirmngr_ldapserver.socnf or with gpgsm's --keyserver option.  This
patch fixes this.  Eventually we should allow to replace host and port
by a partial URI in the same way ldap_initialize does it.  For backward
compatibility we do not yet do that.

Although the dirmngr code accepts an URL (eg. taken from a
certificate), I can't see how the scheme was ever used.  Thus the
patch also detects an ldaps scheme and uses this.  That part has not
been tested, though.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-11-09 11:29:59 +01:00
Werner Koch 2b9d399cf0
doc: Document gpgsm's --keyserver option.
--

Also fix a few related entries.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-11-07 17:41:19 +01:00
NIIBE Yutaka e00e68135c dns: Fix irrelevant use of tmpfile.
* dirmngr/dns.c (dns_trace_open): Don't use tmpfile.

GnuPG-bug-id: 4228
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-08-22 12:51:17 +09:00
NIIBE Yutaka 75e0ec6517 dirmngr: Don't add system CAs for SKS HKPS pool.
* dirmngr/http.c [HTTP_USE_GNUTLS] (http_session_new): Clear
add_system_cas.

GnuPG-bug-id: 4594
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-07-16 10:10:52 +09:00
Daniel Kahn Gillmor 064aeb14c9
dirmngr: fix handling of HTTPS redirections during HKP
* dirmngr/ks-engine-hkp.c (send_request): Reinitialize HTTP session when
following a HTTP redirection.

--
inspired by patch from Damien Goutte-Gattat <dgouttegattat@incenp.org>

GnuPG-Bug_id: 4566
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>

Originally applied to 2.2.  Here a minor conflict fix was needed.
2019-07-04 16:36:18 +02:00
Werner Koch 8b113bb148
dirmngr: Avoid endless loop in case of HTTP error 503.
* dirmngr/ks-engine-hkp.c (SEND_REQUEST_EXTRA_RETRIES): New.
(handle_send_request_error): Use it for 503 and 504.
(ks_hkp_search, ks_hkp_get, ks_hkp_put): Pass a new var for
extra_tries.
--

This is a pretty stupid fix but one which works without much risk of
regressions.  We could have used the existing TRIES but in that case
the fallback to other host would have been too limited.  With the used
value we can have several fallbacks to other hosts.  Note that the
TRIES is still cumulative and not per host.

GnuPG-bug-id: 4600
Signed-off-by: Werner Koch <wk@gnupg.org>
2019-07-03 17:39:53 +02:00
Werner Koch 37f0c55c7b
dirmngr: Do not rewrite the redirection for the "openpgpkey" subdomain.
* dirmngr/http.c (same_host_p): Consider certain subdomains to be the
same.
--

GnuPG-bug-id: 4603
Signed-off-by: Werner Koch <wk@gnupg.org>
2019-07-03 16:20:00 +02:00
Werner Koch 405f41007c
dirmngr: Allow for other hash algorithms than SHA-1 in OCSP.
* dirmngr/ocsp.c (do_ocsp_request): Remove arg md.  Add args r_sigval,
r_produced_at, and r_md.  Get the hash algo from the signature and
create the context here.
(check_signature): Allow any hash algo.  Print a diagnostic if the
signature does not verify.
--

GnuPG-bug-id: 3966
Signed-off-by: Werner Koch <wk@gnupg.org>
2019-05-28 12:27:53 +02:00
Werner Koch 4699e294cc
dirmngr: Improve finding OCSP cert.
* dirmngr/certcache.c (find_cert_bysubject): Add better debug output
and try to locate by keyid.
--

This chnages was suggested in
GnuPG-bug-id: 4536
but we do not have any test cases for this.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-05-28 12:27:53 +02:00
Werner Koch 7098e4ce19
dirmngr: Add a CSRF expection for pm.me
--

Also comment typo fix.
2019-05-09 14:50:41 +02:00
Werner Koch e100ace7f8
dirmngr: Improve domaininfo cache update algorithm.
* dirmngr/domaininfo.c (struct domaininfo_s): Add field keepmark.
(insert_or_update): Implement new update algorithm.

--

The old algorithm limited the length of a bucket chain by purging the
last 50% or the entries.  Thus the first domains entered into the
cache were never purged.  The new algorithm is a bit better: It also
limits the chain length on overflow to 50% but tries to keep the
entries indicating that a WKD is available in the cache.  If there is
still space to keep more, those which clearly do not support WKD are
also kept.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-04-02 13:22:32 +02:00
Werner Koch 21b6740974
dirmngr: Better for error code for http status 413.
* dirmngr/ks-engine-hkp.c (send_request): New case for 413.
* dirmngr/ks-engine-http.c (ks_http_fetch): Ditto.
* dirmngr/ocsp.c (do_ocsp_request): Ditto.
--

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-03-29 14:20:47 +01:00
NIIBE Yutaka 8d1b598213 libdns: Don't use _[A-Z] which are reserved names.
* dirmngr/dns.c: Use the identifiers of "*_instance" instead of
reserved "_[A-Z]".

--

GnuPG-bug-id: 4420
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-03-25 19:39:44 +09:00
Werner Koch bdda31a26b
kbx: Unify the fingerprint search modes.
* kbx/keybox-search-desc.h (KEYDB_SEARCH_MODE_FPR16)
(KEYDB_SEARCH_MODE_FPR20, KEYDB_SEARCH_MODE_FPR32): Remove.  Switch
all users to KEYDB_SEARCH_MODE_FPR along with the fprlen value.
--

These search modes were added over time and there has until recently
be no incentive to remove the cruft.  With the change for v5 keys I
finally went over all places and allowed the generic fingerprint mode
along with a given length of the fingerprint at all places.
Consequently the other modes can now be removed.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-03-14 14:55:06 +01:00
Werner Koch 9f37e93dd7
dirmngr: Avoid testing for Tor with --gpgconf-list.
* dirmngr/dirmngr.c (post_option_parsing): Do not call set_tor_mode.
(dirmngr_sighup_action): Call it here.
(main): Call it here unless in --gpgconf-list mode.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-03-11 18:15:05 +01:00
Werner Koch 134c3c1652
dirmngr: Add CSRF protection exception for protonmail.
* dirmngr/http.c (same_host_p): Add exception table.
--

Please: Adding entries to this table shall be an exception and not the
rule.

Signed-off-by: Werner Koch <wk@gnupg.org>
2019-03-07 11:34:19 +01:00
NIIBE Yutaka 371ae25f8f libdns: Avoid using compound literals (8).
* dirmngr/dns.h (dns_quietinit): Remove.
(dns_hints_i_new): Remove.

--

Even before our change, dns_quietinit was questionable macro;  There
was no place in dns.c which requires overrides in initializer list.
Only redundant zero were.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-02-26 12:26:02 +09:00
NIIBE Yutaka d661acd483 libdns: Avoid using compound literals (7).
* dirmngr/dns.h (DNS_OPTS_INIT, dns_opts): Remove.
* dirmngr/dns-stuff.c (libdns_res_open): Use zero-ed, and initialized
automatic variable for opts.
* dirmngr/dns.c (send_query, resolve_query, resolve_addrinfo):
Likewise.

--

In fact, DNS_OPTS_INIT was only needed when args are none.  With
partially specified initialization, C99 guarantees zero-ed other
members just like static object.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-02-26 12:13:35 +09:00
NIIBE Yutaka 6501e59d36 libdns: Avoid using compound literals (6).
* dirmngr/dns.h (dns_rr_i_new): Remove.
(dns_rr_i_init): Remove unused second argument.
* dirmngr/dns.c (dns_p_dump, dns_hints_query, print_packet)
(parse_packet): Use automatic variable for struct dns_rr_i.
(dns_d_cname): No need to call dns_rr_i_init after memset 0.
(dns_rr_i_init): Remove unused second argument.  Return nothing.
* dirmngr/dns-stuff.c (resolve_addr_libdns, get_dns_cert_libdns)
(getsrv_libdns): Follow the change of dns_rr_i_init.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-02-26 11:55:32 +09:00
NIIBE Yutaka a1ccfe2b37 libdns: Avoid using compound literals (5).
* dirmngr/dns.h (dns_rr_foreach): Don't use dns_rr_i_new.
Call dns_rr_grep with NULL.
* dirmngr/dns.c (dns_rr_grep): Support NULL for error_.

--

Here we still use C99 feature of struct member initialization in
dns_rr_foreach, for struct dns_rr_i.  Note that in C99, it guarantees
non-specified member fields are initialized by zero.  So, there's no
need to use dns_rr_i_new at all.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-02-26 11:53:41 +09:00
NIIBE Yutaka 7313a112f9 libdns: Avoid using compound literals (4).
* dirmngr/dns.h (dns_d_new*): Remove.
* dirmngr/dns.c (parse_packet): Use dns_d_init with automatic
variable.
(parse_domain): Likewise.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-02-26 10:58:16 +09:00
NIIBE Yutaka 72efb78402 libdns: Avoid using compound literals (3).
* dirmngr/dns.h (dns_p_new): Remove.
* dirmngr/dns.c (dns_hosts_query): Use dns_p_init with automatic
variable.
(dns_hints_query, dns_res_glue, parse_packet, query_hosts)
(send_query, show_hints, echo_port): Likewise.

--

Implicit automatic allocation by compound literals is confusing
for C90 code.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-02-26 10:34:03 +09:00
NIIBE Yutaka 455ef62d29 libdns: Avoid using compound literals (2).
* dirmngr/dns.h (dns_strsection1, dns_strsection3): Remove.
(dns_strclass1, dns_strclass3): Remove.
(dns_strtype1, dns_strtype3): Remove.
(dns_strsection, dns_strclass, dns_strtype): Directly use the
function.
* dirmngr/dns.c (dns_strsection): Use automatic variable.
(dns_strclass, dns_strtype): Likewise.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-02-26 10:12:24 +09:00
NIIBE Yutaka 1c40549938 libdns: Avoid using compound literals.
* dirmngr/dns.c (dns_inet_pton, dns_so_tcp_keep): Use automatic
variables.
(dns_poll, dns_send_nopipe): Likewise, adding const qualifier.

--

Compound literals is a feature of C99.  Because we only use C90 plus
some limited features, in the project, it's better to avoid it.

Besides, we make sure when it's read-only.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-02-26 09:42:54 +09:00
NIIBE Yutaka 1f8817475f dirmngr: Fix initialization of assuan's nPth hook.
* dirmngr/dirmngr.c (main): Move assuan_set_system_hooks to...
(thread_init): ... here.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2019-01-25 10:15:39 +09:00
Werner Koch 40c307fa8d
Silence a few compiler warnings new with gcc 8.
* dirmngr/dns.c: Include gpgrt.h.  Silence -Warray-bounds also gcc.
* tools/gpg-pair-tool.c (command_respond): Init two vars to silence
gcc.

Signed-off-by: Werner Koch <wk@gnupg.org>
2018-12-17 18:46:26 +01:00
Werner Koch 05ef628278
dirmngr: Retry another server from the pool on 502, 503, 504.
* dirmngr/ks-engine-hkp.c (handle_send_request_error): Add arg
http_status and handle it.
(ks_hkp_search): Get http_status froms end_request and pass on to
handle_send_request_error.
(ks_hkp_get): Ditto.
(ks_hkp_put): Ditto.
--

GnuPG-bug-id: 4175
Signed-off-by: Werner Koch <wk@gnupg.org>
2018-12-11 13:39:41 +01:00
Werner Koch dc61f4ecea
dirmngr: New function http_status2string.
* dirmngr/http.c (http_status2string): New.
--

Right now only the standard 5xx codes.

Signed-off-by: Werner Koch <wk@gnupg.org>
2018-12-11 13:24:31 +01:00
Werner Koch fa1b1eaa42
dirmngr: Avoid possible CSRF attacks via http redirects.
* dirmngr/http.h (parsed_uri_s): Add fields off_host and off_path.
(http_redir_info_t): New.
* dirmngr/http.c (do_parse_uri): Set new fields.
(same_host_p): New.
(http_prepare_redirect): New.
* dirmngr/t-http-basic.c: New test.
* dirmngr/ks-engine-hkp.c (send_request): Use http_prepare_redirect
instead of the open code.
* dirmngr/ks-engine-http.c (ks_http_fetch): Ditto.
--

With this change a http query will not follow a redirect unless the
Location header gives the same host.  If the host is different only
the host and port is taken from the Location header and the original
path and query parts are kept.

Signed-off-by: Werner Koch <wk@gnupg.org>
2018-11-22 22:36:07 +01:00
Werner Koch 914fa3be22
dirmngr: Support the new WKD draft with the openpgpkey subdomain.
* dirmngr/server.c (proc_wkd_get): Implement new openpgpkey subdomain
method.

Signed-off-by: Werner Koch <wk@gnupg.org>
2018-11-13 11:35:39 +01:00
Andre Heinecke 678e4706ee
dirmngr: Add FLUSHCRLs command
Summary:
* dirmngr/crlcache.c (crl_cache_flush): Also deinit the cache.
* dirmngr/server.c (hlp_flushcrls, cmd_flushcrls): New.
(register_commands): Add FLUSHCRLS.

--
This allows it to flush the CRL cache of a running dirmngr
server. This can be useful to debug / analyze CRL issues.

GnuPG-Bug-Id: T3967

Differential Revision: https://dev.gnupg.org/D469

Signed-off-by: Andre Heinecke <aheinecke@intevation.de>
(cherry picked from commit 00321a025f)
2018-11-12 13:54:26 +01:00
Werner Koch 6b9f772914
common: Prepare for parsing mail sub-addresses.
* common/mbox-util.c (mailbox_from_userid): Add arg subaddress and
implement.  Change all callers to pass false for it.

* common/t-mbox-util.c (run_mbox_no_sub_test): New.
(run_filter): Add arg no_sub.
(main): Call new test and add option --no-sub.
--

Some stats: In the about 5300000 keys on the SKS servers we found 3055
unique mailboxes with a '+' in it.  After removing leading and
trailing '+' as well as multiple '+' (e.g. "c++" or "foo+bar+baz")
2697 were left which seem to be valid sub-addresses.

To filter mailboxes out from a line delimited list with
user-ids (e.g. an SQL output), the command

   t-mbox-util --verbose --filter

can be used; to output w/o sub-addresses add --no-sub.

GnuPG-bug-id: 4200
Signed-off-by: Werner Koch <wk@gnupg.org>
2018-11-12 07:44:33 +01:00
Werner Koch a3a5a24519
dirmngr: Fix LDAP port parsing.
* dirmngr/misc.c (host_and_port_from_url): Fix bad port parsing and a
segv for a missing slash after the host name.
--

Reportted-by: Tomas Mraz
GnuPG-bug-id: 4230
Signed-off-by: Werner Koch <wk@gnupg.org>
2018-11-05 09:00:02 +01:00
Daniel Kahn Gillmor b39ece7d35 headers: fix spelling
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2018-10-25 16:53:05 -04:00
Werner Koch 2b57a8159c
dirmngr: Fix out of scope use of a var in the keyserver LDAP code.
* dirmngr/ks-engine-ldap.c (extract_attributes): Don't use a variabale
out of scope and cleanup the entire pgpKeySize block.
--

GnuPG-bug-id: 4229
Signed-off-by: Werner Koch <wk@gnupg.org>
2018-10-25 17:34:24 +02:00
Daniel Kahn Gillmor 54eb375ff1 all: fix spelling and typos
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2018-10-24 15:56:18 -04:00
Werner Koch 256a280c51
dirmngr: Prepare for updated WKD specs with ?l= param
* dirmngr/server.c (proc_wkd_get): Tack the raw local address to the
request.
--

We append the raw non-canonicalized local address part to the hash.
Servers who serve the requests from static files will ignore the
parameters and a test with posteo shows that also services using a
database ignore the parameter.  The general idea is that service
providers may use their own canonicalization rules.  The problem is
that we currently filter the returned key for the full mail address
and thus we will never see a key if the service did a different
canonicalization than we.  So consider this to be an experiment.

Signed-off-by: Werner Koch <wk@gnupg.org>
2018-10-22 20:13:08 +02:00
Werner Koch 0a7f446c18
dirmngr: In verbose mode print the OCSP responder id.
* dirmngr/ocsp.c (ocsp_isvalid): Print the responder id.

Signed-off-by: Werner Koch <wk@gnupg.org>
2018-10-22 14:23:11 +02:00
NIIBE Yutaka 69bab1cba0 Revert "dirmngr: hkp: Avoid potential race condition when some hosts die."
This reverts commit 04b56eff11.

--

Now the access to hosttable is serialized correctly.
2018-09-11 14:04:37 +09:00
NIIBE Yutaka 995aded587 dirmngr: Serialize access to hosttable.
* dirmngr/dirmngr.h (ks_hkp_init): New.
* dirmngr/dirmngr.c (main): Call ks_hkp_init.
* dirmngr/ks-engine-hkp.c (ks_hkp_init): New.
(ks_hkp_mark_host): Serialize access to hosttable.
(ks_hkp_print_hosttable, make_host_part): Likewise.
(ks_hkp_housekeeping, ks_hkp_reload): Likewise.

--

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2018-09-11 14:02:53 +09:00
Werner Koch bee65edfbc
dirmngr: Emit SOURCE status also on NO_DATA.
* dirmngr/ks-engine-hkp.c (ks_hkp_search): Send SOURCE status also on
NO DATA error.
(ks_hkp_get): Ditto.
* g10/call-dirmngr.c (gpg_dirmngr_ks_search): Print "data source" info
also on error.
(gpg_dirmngr_ks_get): Ditto.
--

If a keyserver does not return any data it can be useful to know which
keyserver out of the pool answered.

Signed-off-by: Werner Koch <wk@gnupg.org>
2018-09-07 11:48:18 +02:00
Daniel Kahn Gillmor 04b56eff11 dirmngr: hkp: Avoid potential race condition when some hosts die.
* dirmngr/ks-engine-hkp.c (select_random_host): Use atomic pass
through the host table instead of risking out-of-bounds write.

--

Multiple threads may write to hosttable[x]->dead while
select_random_host() is running.  For example, a housekeeping thread
might clear the ->dead bit on some entries, or another connection to
dirmngr might manually mark a host as alive.

If one or more hosts are resurrected between the two loops over a
given table in select_random_host(), then the allocation of tbl might
not be large enough, resulting in a write past the end of tbl on the
second loop.

This change collapses the two loops into a single loop to avoid this
discrepancy: each host's "dead" bit is now only checked once.

As Werner points out, this isn't currently strictly necessary, since
npth will not switch threads unless a blocking system call is made,
and no blocking system call is made in these two loops.

However, in a subsequent change in this series, we will call a
function in this loop, and that function may sometimes write(2), or
call other functions, which may themselves block.  Keeping this as a
single-pass loop avoids the need to keep track of what might block and
what might not.

GnuPG-bug-id: 2836
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2018-09-07 14:28:11 +09:00