/* RECIPIENT [--hidden] <userID>
Set the recipient for the encryption. <userID> should be the
internal representation of the key; the server may accept any other
way of specification. If this is a valid and trusted recipient the
server does respond with OK, otherwise the return is an ERR with
the reason why the recipient can't be used, the encryption will
then not be done for this recipient. If the policy is not to
encrypt at all if not all recipients are valid, the client has to
take care of this. All RECIPIENT commands are cumulative until a
RESET or an successful ENCRYPT command. */
static gpg_error_t
cmd_recipient (assuan_context_t ctx, char *line)
{
ctrl_t ctrl = assuan_get_pointer (ctx);
gpg_error_t err;
int hidden;
hidden = has_option (line,"--hidden");
line = skip_options (line);
/* FIXME: Expand groups
if (opt.grouplist)
remusr = expand_group (rcpts);
else
remusr = rcpts;
*/
err = find_and_check_key (ctrl, line, PUBKEY_USAGE_ENC, hidden,
&ctrl->server_local->recplist);
if (err)
log_error ("command '%s' failed: %s\n", "RECIPIENT", gpg_strerror (err));
return err;
}
/* This is the central function to collect the keys for recipients.
It is thus used to prepare a public key encryption. encrypt-to
keys, default keys and the keys for the actual recipients are all
collected here. When not in batch mode and no recipient has been
passed on the commandline, the function will also ask for
recipients.
RCPTS is a string list with the recipients; NULL is an allowed
value but not very useful. Group expansion is done on these names;
they may be in any of the user Id formats we can handle. The flags
bits for each string in the string list are used for:
Bit 0: This is an encrypt-to recipient.
Bit 1: This is a hidden recipient.
USE is the desired use for the key - usually PUBKEY_USAGE_ENC.
On success a list of keys is stored at the address RET_PK_LIST; the
caller must free this list. On error the value at this address is
not changed.
*/
int
build_pk_list (ctrl_t ctrl,
strlist_t rcpts, PK_LIST *ret_pk_list, unsigned int use )
{
PK_LIST pk_list = NULL;
PKT_public_key *pk=NULL;
int rc=0;
int any_recipients=0;
strlist_t rov,remusr;
char *def_rec = NULL;
/* Try to expand groups if any have been defined. */
if (opt.grouplist)
remusr = expand_group (rcpts);
else
remusr = rcpts;
/* Check whether there are any recipients in the list and build the
* list of the encrypt-to ones (we always trust them). */
for ( rov = remusr; rov; rov = rov->next )
{
if ( !(rov->flags & 1) )
{
/* This is a regular recipient; i.e. not an encrypt-to
one. */
any_recipients = 1;
/* Hidden recipients are not allowed while in PGP mode,
issue a warning and switch into GnuPG mode. */
if ((rov->flags&2) && (PGP2 || PGP6 || PGP7 || PGP8))
{
log_info(_("you may not use %s while in %s mode\n"),
"--hidden-recipient",
compliance_option_string());
compliance_failure();
}
}
else if ( (use & PUBKEY_USAGE_ENC) && !opt.no_encrypt_to )
{
/* Encryption has been requested and --encrypt-to has not
been disabled. Check this encrypt-to key. */
pk = xmalloc_clear( sizeof *pk );
pk->req_usage = use;
/* We explicitly allow encrypt-to to an disabled key; thus
we pass 1for the second last argument and 1 as the last
argument to disable AKL. */
if ( (rc = get_pubkey_byname (ctrl,
NULL, pk, rov->d, NULL, NULL, 1, 1)) )
{
free_public_key ( pk ); pk = NULL;
log_error (_("%s: skipped: %s\n"), rov->d, g10_errstr(rc) );
send_status_inv_recp (0, rov->d);
goto fail;
}
else if ( !(rc=openpgp_pk_test_algo2 (pk->pubkey_algo, use)) )
{
/* Skip the actual key if the key is already present
* in the list. Add it to our list if not. */
if (key_present_in_pk_list(pk_list, pk) == 0)
{
free_public_key (pk); pk = NULL;
log_info (_("%s: skipped: public key already present\n"),
rov->d);
}
else
{
PK_LIST r;
r = xmalloc( sizeof *r );
r->pk = pk; pk = NULL;
r->next = pk_list;
r->flags = (rov->flags&2)?1:0;
pk_list = r;
/* Hidden encrypt-to recipients are not allowed while
in PGP mode, issue a warning and switch into
GnuPG mode. */
if ((r->flags&1) && (PGP2 || PGP6 || PGP7 || PGP8))
{
log_info(_("you may not use %s while in %s mode\n"),
"--hidden-encrypt-to",
compliance_option_string());
compliance_failure();
}
}
}
else
{
/* The public key is not usable for encryption or not
available. */
free_public_key( pk ); pk = NULL;
log_error(_("%s: skipped: %s\n"), rov->d, g10_errstr(rc) );
send_status_inv_recp (0, rov->d);
goto fail;
}
}
}
/* If we don't have any recipients yet and we are not in batch mode
drop into interactive selection mode. */
if ( !any_recipients && !opt.batch )
{
int have_def_rec;
char *answer = NULL;
strlist_t backlog = NULL;
if (pk_list)
any_recipients = 1;
def_rec = default_recipient();
have_def_rec = !!def_rec;
if ( !have_def_rec )
tty_printf(_("You did not specify a user ID. (you may use \"-r\")\n"));
for (;;)
{
rc = 0;
xfree(answer);
if ( have_def_rec )
{
/* A default recipient is taken as the first entry. */
answer = def_rec;
def_rec = NULL;
}
else if (backlog)
{
/* This is part of our trick to expand and display groups. */
answer = strlist_pop (&backlog);
}
else
{
/* Show the list of already collected recipients and ask
for more. */
PK_LIST iter;
tty_printf("\n");
tty_printf(_("Current recipients:\n"));
for (iter=pk_list;iter;iter=iter->next)
{
u32 keyid[2];
keyid_from_pk(iter->pk,keyid);
tty_printf("%4u%c/%s %s \"",
nbits_from_pk(iter->pk),
pubkey_letter(iter->pk->pubkey_algo),
keystr(keyid),
datestr_from_pk(iter->pk));
if (iter->pk->user_id)
tty_print_utf8_string(iter->pk->user_id->name,
iter->pk->user_id->len);
else
{
size_t n;
char *p = get_user_id( keyid, &n );
tty_print_utf8_string( p, n );
xfree(p);
}
tty_printf("\"\n");
}
answer = cpr_get_utf8("pklist.user_id.enter",
_("\nEnter the user ID. "
"End with an empty line: "));
trim_spaces(answer);
cpr_kill_prompt();
}
if ( !answer || !*answer )
{
xfree(answer);
break; /* No more recipients entered - get out of loop. */
}
/* Do group expand here too. The trick here is to continue
the loop if any expansion occured. The code above will
then list all expanded keys. */
if (expand_id(answer,&backlog,0))
continue;
/* Get and check key for the current name. */
free_public_key (pk);
pk = xmalloc_clear( sizeof *pk );
pk->req_usage = use;
rc = get_pubkey_byname (ctrl, NULL, pk, answer, NULL, NULL, 0, 0 );
if (rc)
tty_printf(_("No such user ID.\n"));
else if ( !(rc=openpgp_pk_test_algo2 (pk->pubkey_algo, use)) )
{
if ( have_def_rec )
{
/* No validation for a default recipient. */
if (!key_present_in_pk_list(pk_list, pk))
{
free_public_key (pk);
pk = NULL;
log_info (_("skipped: public key "
"already set as default recipient\n") );
}
else
{
PK_LIST r = xmalloc (sizeof *r);
r->pk = pk; pk = NULL;
r->next = pk_list;
r->flags = 0; /* No throwing default ids. */
pk_list = r;
}
any_recipients = 1;
continue;
}
else
{ /* Check validity of this key. */
int trustlevel;
trustlevel = get_validity (pk, pk->user_id);
if ( (trustlevel & TRUST_FLAG_DISABLED) )
{
tty_printf (_("Public key is disabled.\n") );
}
else if ( do_we_trust_pre (pk, trustlevel) )
{
/* Skip the actual key if the key is already
* present in the list */
if (!key_present_in_pk_list(pk_list, pk))
{
free_public_key (pk);
pk = NULL;
log_info(_("skipped: public key already set\n") );
}
else
{
PK_LIST r;
r = xmalloc( sizeof *r );
r->pk = pk; pk = NULL;
r->next = pk_list;
r->flags = 0; /* No throwing interactive ids. */
pk_list = r;
}
any_recipients = 1;
continue;
}
}
}
xfree(def_rec); def_rec = NULL;
have_def_rec = 0;
}
if ( pk )
{
free_public_key( pk );
pk = NULL;
}
}
else if ( !any_recipients && (def_rec = default_recipient()) )
{
/* We are in batch mode and have only a default recipient. */
pk = xmalloc_clear( sizeof *pk );
pk->req_usage = use;
/* The default recipient is allowed to be disabled; thus pass 1
as second last argument. We also don't want an AKL. */
rc = get_pubkey_byname (ctrl, NULL, pk, def_rec, NULL, NULL, 1, 1);
if (rc)
log_error(_("unknown default recipient \"%s\"\n"), def_rec );
else if ( !(rc=openpgp_pk_test_algo2(pk->pubkey_algo, use)) )
{
/* Mark any_recipients here since the default recipient
would have been used if it wasn't already there. It
doesn't really matter if we got this key from the default
recipient or an encrypt-to. */
any_recipients = 1;
if (!key_present_in_pk_list(pk_list, pk))
log_info (_("skipped: public key already set "
"as default recipient\n"));
else
{
PK_LIST r = xmalloc( sizeof *r );
r->pk = pk; pk = NULL;
r->next = pk_list;
r->flags = 0; /* No throwing default ids. */
pk_list = r;
}
}
if ( pk )
{
free_public_key( pk );
pk = NULL;
}
xfree(def_rec); def_rec = NULL;
}
else
{
/* General case: Check all keys. */
any_recipients = 0;
for (; remusr; remusr = remusr->next )
{
if ( (remusr->flags & 1) )
continue; /* encrypt-to keys are already handled. */
rc = find_and_check_key (ctrl, remusr->d, use, !!(remusr->flags&2),
&pk_list);
if (rc)
goto fail;
any_recipients = 1;
}
}
if ( !rc && !any_recipients )
{
log_error(_("no valid addressees\n"));
write_status_text (STATUS_NO_RECP, "0");
rc = G10ERR_NO_USER_ID;
}
fail:
if ( rc )
release_pk_list( pk_list );
else
*ret_pk_list = pk_list;
if (opt.grouplist)
free_strlist(remusr);
return rc;
}
