* g10/keyserver.c (ks_retrieval_filter_arg_s): new.
(keyserver_retrieval_filter): Use new struct and check all
descriptions.
(keyserver_spawn): Pass filter arg suing the new struct.
--
This is a fix for commit 52303043.
The old code did only work for a single key. It failed as soon as
several keys are specified ("gpg --refresh-keys" or "gpg --recv-key A
B C").
* g10/main.h: Typedef import_filter for filter callbacks.
* g10/import.c (import): Add filter callbacks to param list.
(import_one): Ditto.
(import_secret_one): Ditto.
(import_keys_internal): Ditto.
(import_keys_stream): Ditto.
* g10/keyserver.c (keyserver_retrieval_filter): New.
(keyserver_spawn): Pass filter to import_keys_stream()
--
These changes introduces import functions that apply a constraining
filter to imported keys. These filters can verify the fingerprints of
the keys returned before importing them into the keyring, ensuring that
the keys fetched from the keyserver are in fact those selected by the
user beforehand.
Signed-off-by: Stefan Tomanek <tomanek@internet-sicherheit.de>
Re-indention and minor changes by wk.
* g10/options.h (IMPORT_NO_SECKEY): New.
* g10/keyserver.c (keyserver_spawn, keyserver_import_cert): Set new
flag.
* g10/import.c (import_secret_one): Deny import if flag is set.
--
By modifying a keyserver or a DNS record to send a secret key, an
attacker could trick a user into signing using a different key and
user id. The trust model should protect against such rogue keys but
we better make sure that secret keys are never received from remote
sources.
Suggested-by: Stefan Tomanek
Signed-off-by: Werner Koch <wk@gnupg.org>
(cherry picked from commit e7abed3448c1c1a4e756c12f95b665b517d22ebe)
Resolved conflicts:
g10/options.h
* keyserver.c (print_keyrec): Honor --keyid-format when getting back
full fingerprints from the keyserver (the comment in the code was
correct, the code was not).
same API as the other auto-key-locate fetchers.
* getkey.c (get_pubkey_byname): Use the fingerprint of the key that we
actually fetched. This helps prevent problems where the key that we
fetched doesn't have the same name that we used to fetch it. In the
case of CERT and PKA, this is an actual security requirement as the
URL might point to a key put in by an attacker. By forcing the use of
the fingerprint, we won't use the attacker's key here.
--no-auto-key-locate.
* options.h, gpg.c (main): Keep track of each keyserver registered so
we can match on them later.
* keyserver-internal.h, keyserver.c (cmp_keyserver_spec,
keyserver_match), gpgv.c: New. Find a keyserver that matches ours and
return its spec.
* getkey.c (get_pubkey_byname): Use it here to get the per-keyserver
options from an earlier keyserver.
(parse_keyserver_options): Moved from here. (parse_keyserver_uri): Use it
here so each keyserver can have some private options in addition to the
main keyserver-options (e.g. per-keyserver auth).
importing at -r time. The URL in the PKA record may point to a key put in
by an attacker. Fix is to use the fingerprint from the PKA record as the
recipient. This ensures that the PKA record is followed.
* keyserver-internal.h, keyserver.c (keyserver_import_pka): Return the
fingerprint we requested.
(keyserver_import_pka), card-util.c (fetch_url): Always require a
scheme:// for keyserver URLs except when used as part of the
--keyserver command for backwards compatibility.
getkey.c:get_pubkey_byname which was getting crowded.
* keyserver.c (keyserver_import_cert): Import a key found in DNS via CERT
records. Can handle both the PGP (actual key) and IPGP (URL) CERT types.
* getkey.c (get_pubkey_byname): Call them both here.
* options.h, keyserver.c (parse_keyserver_options): Add
"auto-cert-retrieve" option with optional max size argument.
* keyserver-internal.h, keyserver.c (keyserver_spawn, keyserver_work,
keygerver_getname): New keyserver_getname function to fetch keys by name.
* getkey.c (get_pubkey_byname): Call it here to enable locating keys by
full mailbox from a keyserver a la PKA. Try PKA first, though, as it is
likely to be faster.
keyserver_fetch): Set a flag to indicate that we're doing a direct URI
fetch so we can differentiate between a keyserver operation and a URI
fetch for protocols like LDAP that can do either.
when fetching a URI.
* keyserver-internal.h, keyserver.c (keyserver_fetch): New. Fetch an
arbitrary URI using the keyserver helpers.
* gpg.c (main): Call it from here for --fetch-keys.
algorithms.
* keyedit.c (sign_uids): Don't request a signing key to make a
certification.
* keygen.c (do_add_key_flags): Force the certify flag on for all
primary keys, as the spec requires primary keys must be able to
certify (if nothing else, which key is going to issue the user ID
signature?) (print_key_flags): Show certify flag. (ask_key_flags,
ask_algo): Don't allow setting the C flag for subkeys.
* keyid.c (usagestr_from_pk), getkey.c (parse_key_usage): Distinguish
between a sign/certify key and a certify-only key.
* main.h, misc.c (path_access): New. Same as access() but does a PATH
search like execlp.
* keyserver.c (curl_can_handle): Removed. Replaced by...
(curl_cant_handle): We are now relying on curl as the handler of last
resort. This is necessary because PGP LDAP and curl LDAP are apples
and oranges. (keyserver_typemap): Only test for ldap and ldaps.
(keyserver_spawn): If a given handler is unusable (as determined by
path_access()) then try gpgkeys_curl.
