/*
* Write pubkey-enc packets from the list of PKs to OUT.
*/
static int
write_pubkey_enc_from_list (ctrl_t ctrl, PK_LIST pk_list, DEK *dek, iobuf_t out)
{
if (opt.throw_keyids && (PGP7 || PGP8))
{
log_info(_("option '%s' may not be used in %s mode\n"),
"--throw-keyids",
gnupg_compliance_option_string (opt.compliance));
compliance_failure();
}
for ( ; pk_list; pk_list = pk_list->next )
{
PKT_public_key *pk = pk_list->pk;
int throw_keyid = (opt.throw_keyids || (pk_list->flags&1));
int rc = write_pubkey_enc (ctrl, pk, throw_keyid, dek, out);
if (rc)
return rc;
}
return 0;
}
/****************
* Write pubkey-enc packets from the list of PKs to OUT.
*/
static int
write_pubkey_enc_from_list( PK_LIST pk_list, DEK *dek, IOBUF out )
{
PACKET pkt;
PKT_public_key *pk;
PKT_pubkey_enc *enc;
int rc;
for( ; pk_list; pk_list = pk_list->next ) {
MPI frame;
pk = pk_list->pk;
print_pubkey_algo_note( pk->pubkey_algo );
enc = xmalloc_clear( sizeof *enc );
enc->pubkey_algo = pk->pubkey_algo;
keyid_from_pk( pk, enc->keyid );
enc->throw_keyid = (opt.throw_keyid || (pk_list->flags&1));
if(opt.throw_keyid && (PGP2 || PGP6 || PGP7 || PGP8))
{
log_info(_("you may not use %s while in %s mode\n"),
"--throw-keyid",compliance_option_string());
compliance_failure();
}
/* Okay, what's going on: We have the session key somewhere in
* the structure DEK and want to encode this session key in
* an integer value of n bits. pubkey_nbits gives us the
* number of bits we have to use. We then encode the session
* key in some way and we get it back in the big intger value
* FRAME. Then we use FRAME, the public key PK->PKEY and the
* algorithm number PK->PUBKEY_ALGO and pass it to pubkey_encrypt
* which returns the encrypted value in the array ENC->DATA.
* This array has a size which depends on the used algorithm
* (e.g. 2 for Elgamal). We don't need frame anymore because we
* have everything now in enc->data which is the passed to
* build_packet()
*/
frame = encode_session_key( dek, pubkey_nbits( pk->pubkey_algo,
pk->pkey ) );
rc = pubkey_encrypt( pk->pubkey_algo, enc->data, frame, pk->pkey );
mpi_free( frame );
if( rc )
log_error("pubkey_encrypt failed: %s\n", g10_errstr(rc) );
else {
if( opt.verbose ) {
char *ustr = get_user_id_string_native (enc->keyid);
log_info(_("%s/%s encrypted for: \"%s\"\n"),
pubkey_algo_to_string(enc->pubkey_algo),
cipher_algo_to_string(dek->algo), ustr );
xfree(ustr);
}
/* and write it */
init_packet(&pkt);
pkt.pkttype = PKT_PUBKEY_ENC;
pkt.pkt.pubkey_enc = enc;
rc = build_packet( out, &pkt );
if( rc )
log_error("build_packet(pubkey_enc) failed: %s\n", g10_errstr(rc));
}
free_pubkey_enc(enc);
if( rc )
return rc;
}
return 0;
}
/****************
* Encrypt the file with the given userids (or ask if none
* is supplied).
*/
int
encode_crypt( const char *filename, STRLIST remusr, int use_symkey )
{
IOBUF inp = NULL, out = NULL;
PACKET pkt;
PKT_plaintext *pt = NULL;
DEK *symkey_dek = NULL;
STRING2KEY *symkey_s2k = NULL;
int rc = 0, rc2 = 0;
u32 filesize;
cipher_filter_context_t cfx;
armor_filter_context_t afx;
compress_filter_context_t zfx;
text_filter_context_t tfx;
progress_filter_context_t pfx;
PK_LIST pk_list,work_list;
int do_compress = opt.compress_algo && !RFC1991;
memset( &cfx, 0, sizeof cfx);
memset( &afx, 0, sizeof afx);
memset( &zfx, 0, sizeof zfx);
memset( &tfx, 0, sizeof tfx);
init_packet(&pkt);
if(use_symkey
&& (rc=setup_symkey(&symkey_s2k,&symkey_dek)))
return rc;
if( (rc=build_pk_list( remusr, &pk_list, PUBKEY_USAGE_ENC)) )
return rc;
if(PGP2) {
for(work_list=pk_list; work_list; work_list=work_list->next)
if(!(is_RSA(work_list->pk->pubkey_algo) &&
nbits_from_pk(work_list->pk)<=2048))
{
log_info(_("you can only encrypt to RSA keys of 2048 bits or "
"less in --pgp2 mode\n"));
compliance_failure();
break;
}
}
/* prepare iobufs */
inp = iobuf_open(filename);
if (inp)
iobuf_ioctl (inp,3,1,NULL); /* disable fd caching */
if (inp && is_secured_file (iobuf_get_fd (inp)))
{
iobuf_close (inp);
inp = NULL;
errno = EPERM;
}
if( !inp ) {
log_error(_("can't open `%s': %s\n"), filename? filename: "[stdin]",
strerror(errno) );
rc = G10ERR_OPEN_FILE;
goto leave;
}
else if( opt.verbose )
log_info(_("reading from `%s'\n"), filename? filename: "[stdin]");
handle_progress (&pfx, inp, filename);
if( opt.textmode )
iobuf_push_filter( inp, text_filter, &tfx );
if( (rc = open_outfile( filename, opt.armor? 1:0, &out )) )
goto leave;
if( opt.armor )
iobuf_push_filter( out, armor_filter, &afx );
/* create a session key */
cfx.dek = xmalloc_secure_clear (sizeof *cfx.dek);
if( !opt.def_cipher_algo ) { /* try to get it from the prefs */
cfx.dek->algo = select_algo_from_prefs(pk_list,PREFTYPE_SYM,-1,NULL);
/* The only way select_algo_from_prefs can fail here is when
mixing v3 and v4 keys, as v4 keys have an implicit
preference entry for 3DES, and the pk_list cannot be empty.
In this case, use 3DES anyway as it's the safest choice -
perhaps the v3 key is being used in an OpenPGP
implementation and we know that the implementation behind
any v4 key can handle 3DES. */
if( cfx.dek->algo == -1 ) {
cfx.dek->algo = CIPHER_ALGO_3DES;
if( PGP2 ) {
log_info(_("unable to use the IDEA cipher for all of the keys "
"you are encrypting to.\n"));
compliance_failure();
}
}
}
else {
if(!opt.expert &&
select_algo_from_prefs(pk_list,PREFTYPE_SYM,
opt.def_cipher_algo,NULL)!=opt.def_cipher_algo)
log_info(_("WARNING: forcing symmetric cipher %s (%d)"
" violates recipient preferences\n"),
cipher_algo_to_string(opt.def_cipher_algo),
opt.def_cipher_algo);
cfx.dek->algo = opt.def_cipher_algo;
}
cfx.dek->use_mdc=use_mdc(pk_list,cfx.dek->algo);
/* Only do the is-file-already-compressed check if we are using a
MDC. This forces compressed files to be re-compressed if we do
not have a MDC to give some protection against chosen
ciphertext attacks. */
if (do_compress && cfx.dek->use_mdc && is_file_compressed(filename, &rc2) )
{
if (opt.verbose)
log_info(_("`%s' already compressed\n"), filename);
do_compress = 0;
}
if (rc2)
{
rc = rc2;
goto leave;
}
make_session_key( cfx.dek );
if( DBG_CIPHER )
log_hexdump("DEK is: ", cfx.dek->key, cfx.dek->keylen );
rc = write_pubkey_enc_from_list( pk_list, cfx.dek, out );
if( rc )
goto leave;
/* We put the passphrase (if any) after any public keys as this
seems to be the most useful on the recipient side - there is no
point in prompting a user for a passphrase if they have the
secret key needed to decrypt. */
if(use_symkey && (rc=write_symkey_enc(symkey_s2k,symkey_dek,cfx.dek,out)))
goto leave;
if (!opt.no_literal) {
/* setup the inner packet */
if( filename || opt.set_filename ) {
char *s = make_basename( opt.set_filename ? opt.set_filename
: filename,
iobuf_get_real_fname( inp ) );
pt = xmalloc( sizeof *pt + strlen(s) - 1 );
pt->namelen = strlen(s);
memcpy(pt->name, s, pt->namelen );
xfree(s);
}
else { /* no filename */
pt = xmalloc( sizeof *pt - 1 );
pt->namelen = 0;
}
}
if (!iobuf_is_pipe_filename (filename) && *filename && !opt.textmode )
{
off_t tmpsize;
int overflow;
if ( !(tmpsize = iobuf_get_filelength(inp, &overflow))
&& !overflow )
log_info(_("WARNING: `%s' is an empty file\n"), filename );
/* We can't encode the length of very large files because
OpenPGP uses only 32 bit for file sizes. So if the the
size of a file is larger than 2^32 minus some bytes for
packet headers, we switch to partial length encoding. */
if (tmpsize < (IOBUF_FILELENGTH_LIMIT - 65536) )
filesize = tmpsize;
else
filesize = 0;
}
else
filesize = opt.set_filesize ? opt.set_filesize : 0; /* stdin */
if (!opt.no_literal) {
pt->timestamp = make_timestamp();
pt->mode = opt.textmode ? 't' : 'b';
pt->len = filesize;
pt->new_ctb = !pt->len && !RFC1991;
pt->buf = inp;
pkt.pkttype = PKT_PLAINTEXT;
pkt.pkt.plaintext = pt;
cfx.datalen = filesize && !do_compress? calc_packet_length( &pkt ) : 0;
}
else
cfx.datalen = filesize && !do_compress ? filesize : 0;
/* register the cipher filter */
iobuf_push_filter( out, cipher_filter, &cfx );
/* register the compress filter */
if( do_compress ) {
int compr_algo = opt.compress_algo;
if(compr_algo==-1)
{
if((compr_algo=
select_algo_from_prefs(pk_list,PREFTYPE_ZIP,-1,NULL))==-1)
compr_algo=DEFAULT_COMPRESS_ALGO;
/* Theoretically impossible to get here since uncompressed
is implicit. */
}
else if(!opt.expert &&
select_algo_from_prefs(pk_list,PREFTYPE_ZIP,
compr_algo,NULL)!=compr_algo)
log_info(_("WARNING: forcing compression algorithm %s (%d)"
" violates recipient preferences\n"),
compress_algo_to_string(compr_algo),compr_algo);
/* algo 0 means no compression */
if( compr_algo )
{
if (cfx.dek && cfx.dek->use_mdc)
zfx.new_ctb = 1;
push_compress_filter(out,&zfx,compr_algo);
}
}
/* do the work */
if (!opt.no_literal) {
if( (rc = build_packet( out, &pkt )) )
log_error("build_packet failed: %s\n", g10_errstr(rc) );
}
else {
/* user requested not to create a literal packet, so we copy
the plain data */
byte copy_buffer[4096];
int bytes_copied;
while ((bytes_copied = iobuf_read(inp, copy_buffer, 4096)) != -1)
if (iobuf_write(out, copy_buffer, bytes_copied) == -1) {
rc = G10ERR_WRITE_FILE;
log_error("copying input to output failed: %s\n",
g10_errstr(rc) );
break;
}
wipememory(copy_buffer, 4096); /* burn buffer */
}
/* finish the stuff */
leave:
iobuf_close(inp);
if( rc )
iobuf_cancel(out);
else {
iobuf_close(out); /* fixme: check returncode */
write_status( STATUS_END_ENCRYPTION );
}
if( pt )
pt->buf = NULL;
free_packet(&pkt);
xfree(cfx.dek);
xfree(symkey_dek);
xfree(symkey_s2k);
release_pk_list( pk_list );
return rc;
}
/* 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.
RET_PK_LIST.
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( STRLIST 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 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 1 as last argument. */
if ( (rc = get_pubkey_byname ( pk, rov->d, NULL, NULL, 1 )) )
{
free_public_key ( pk ); pk = NULL;
log_error (_("%s: skipped: %s\n"), rov->d, g10_errstr(rc) );
write_status_text_and_buffer (STATUS_INV_RECP, "0 ",
rov->d, strlen (rov->d), -1);
goto fail;
}
else if ( !(rc=check_pubkey_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) );
write_status_text_and_buffer (STATUS_INV_RECP, "0 ",
rov->d, strlen (rov->d), -1);
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 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 = pop_strlist (&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. */
if (pk)
free_public_key (pk);
pk = xmalloc_clear( sizeof *pk );
pk->req_usage = use;
rc = get_pubkey_byname( pk, answer, NULL, NULL, 0 );
if (rc)
tty_printf(_("No such user ID.\n"));
else if ( !(rc=check_pubkey_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 last argument. */
rc = get_pubkey_byname (pk, def_rec, NULL, NULL, 1);
if (rc)
log_error(_("unknown default recipient \"%s\"\n"), def_rec );
else if ( !(rc=check_pubkey_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. */
pk = xmalloc_clear( sizeof *pk );
pk->req_usage = use;
if ( (rc = get_pubkey_byname( pk, remusr->d, NULL, NULL, 0 )) )
{
/* Key not found or other error. */
free_public_key( pk ); pk = NULL;
log_error(_("%s: skipped: %s\n"), remusr->d, g10_errstr(rc) );
write_status_text_and_buffer (STATUS_INV_RECP, "0 ",
remusr->d, strlen (remusr->d),
-1);
goto fail;
}
else if ( !(rc=check_pubkey_algo2(pk->pubkey_algo, use )) )
{
/* Key found and usable. Check validity. */
int trustlevel;
trustlevel = get_validity (pk, pk->user_id);
if ( (trustlevel & TRUST_FLAG_DISABLED) )
{
/*Key has been disabled. */
free_public_key(pk); pk = NULL;
log_info(_("%s: skipped: public key is disabled\n"),
remusr->d);
write_status_text_and_buffer (STATUS_INV_RECP, "0 ",
remusr->d,
strlen (remusr->d),
-1);
rc=G10ERR_UNU_PUBKEY;
goto fail;
}
else if ( do_we_trust_pre( pk, trustlevel ) )
{
/* Note: do_we_trust may have changed the trustlevel */
/* We have at least one valid recipient. It doesn't
* matters if this recipient is already present. */
any_recipients = 1;
/* 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(_("%s: skipped: public key already present\n"),
remusr->d);
}
else
{
PK_LIST r;
r = xmalloc( sizeof *r );
r->pk = pk; pk = NULL;
r->next = pk_list;
r->flags = (remusr->flags&2)?1:0;
pk_list = r;
}
}
else
{ /* We don't trust this key. */
free_public_key( pk ); pk = NULL;
write_status_text_and_buffer (STATUS_INV_RECP, "10 ",
remusr->d,
strlen (remusr->d),
-1);
rc=G10ERR_UNU_PUBKEY;
goto fail;
}
}
else
{
/* Key found but not usable for us (e.g. sign-only key). */
free_public_key( pk ); pk = NULL;
write_status_text_and_buffer (STATUS_INV_RECP, "0 ",
remusr->d,
strlen (remusr->d),
-1);
log_error(_("%s: skipped: %s\n"), remusr->d, g10_errstr(rc) );
goto fail;
}
}
}
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;
}
