/* Return a new DEK object using the string-to-key specifier S2K. Use
KEYID and PUBKEY_ALGO to prompt the user. Returns NULL is the user
selected to cancel the passphrase entry and if CANCELED is not
NULL, sets it to true.
MODE 0: Allow cached passphrase
1: Ignore cached passphrase
2: Ditto, but create a new key
3: Allow cached passphrase; use the S2K salt as the cache ID
4: Ditto, but create a new key
*/
DEK *
passphrase_to_dek_ext (u32 *keyid, int pubkey_algo,
int cipher_algo, STRING2KEY *s2k, int mode,
const char *tryagain_text,
const char *custdesc, const char *custprompt,
int *canceled)
{
char *pw = NULL;
DEK *dek;
STRING2KEY help_s2k;
int dummy_canceled;
char s2k_cacheidbuf[1+16+1], *s2k_cacheid = NULL;
if (!canceled)
canceled = &dummy_canceled;
*canceled = 0;
if ( !s2k )
{
log_assert (mode != 3 && mode != 4);
/* This is used for the old rfc1991 mode
* Note: This must match the code in encode.c with opt.rfc1991 set */
s2k = &help_s2k;
s2k->mode = 0;
s2k->hash_algo = S2K_DIGEST_ALGO;
}
/* Create a new salt or what else to be filled into the s2k for a
new key. */
if ((mode == 2 || mode == 4) && (s2k->mode == 1 || s2k->mode == 3))
{
gcry_randomize (s2k->salt, 8, GCRY_STRONG_RANDOM);
if ( s2k->mode == 3 )
{
/* We delay the encoding until it is really needed. This is
if we are going to dynamically calibrate it, we need to
call out to gpg-agent and that should not be done during
option processing in main(). */
if (!opt.s2k_count)
opt.s2k_count = encode_s2k_iterations (0);
s2k->count = opt.s2k_count;
}
}
/* If we do not have a passphrase available in NEXT_PW and status
information are request, we print them now. */
if ( !next_pw && is_status_enabled() )
{
char buf[50];
if ( keyid )
{
emit_status_need_passphrase (keyid,
keyid[2] && keyid[3]? keyid+2:NULL,
pubkey_algo);
}
else
{
snprintf (buf, sizeof buf -1, "%d %d %d",
cipher_algo, s2k->mode, s2k->hash_algo );
write_status_text ( STATUS_NEED_PASSPHRASE_SYM, buf );
}
}
/* If we do have a keyID, we do not have a passphrase available in
NEXT_PW, we are not running in batch mode and we do not want to
ignore the passphrase cache (mode!=1), print a prompt with
information on that key. */
if ( keyid && !opt.batch && !next_pw && mode!=1 )
{
PKT_public_key *pk = xmalloc_clear( sizeof *pk );
char *p;
p = get_user_id_native(keyid);
tty_printf ("\n");
tty_printf (_("You need a passphrase to unlock the secret key for\n"
"user: \"%s\"\n"),p);
xfree(p);
if ( !get_pubkey( pk, keyid ) )
{
const char *s = openpgp_pk_algo_name ( pk->pubkey_algo );
tty_printf (_("%u-bit %s key, ID %s, created %s"),
nbits_from_pk( pk ), s?s:"?", keystr(keyid),
strtimestamp(pk->timestamp) );
if ( keyid[2] && keyid[3]
&& keyid[0] != keyid[2] && keyid[1] != keyid[3] )
{
if ( keystrlen () > 10 )
{
tty_printf ("\n");
tty_printf (_(" (subkey on main key ID %s)"),
keystr(&keyid[2]) );
}
else
tty_printf ( _(" (main key ID %s)"), keystr(&keyid[2]) );
}
tty_printf("\n");
}
tty_printf("\n");
free_public_key (pk);
}
if ( next_pw )
{
/* Simply return the passphrase we already have in NEXT_PW. */
pw = next_pw;
next_pw = NULL;
}
else if ( have_static_passphrase () )
{
/* Return the passphrase we have stored in FD_PASSWD. */
pw = xmalloc_secure ( strlen(fd_passwd)+1 );
strcpy ( pw, fd_passwd );
}
else
{
if ((mode == 3 || mode == 4) && (s2k->mode == 1 || s2k->mode == 3))
{
memset (s2k_cacheidbuf, 0, sizeof s2k_cacheidbuf);
*s2k_cacheidbuf = 'S';
bin2hex (s2k->salt, 8, s2k_cacheidbuf + 1);
s2k_cacheid = s2k_cacheidbuf;
}
if (opt.pinentry_mode == PINENTRY_MODE_LOOPBACK)
{
char buf[32];
snprintf (buf, sizeof (buf), "%u", 100);
write_status_text (STATUS_INQUIRE_MAXLEN, buf);
}
/* Divert to the gpg-agent. */
pw = passphrase_get (keyid, mode == 2, s2k_cacheid,
(mode == 2 || mode == 4)? opt.passphrase_repeat : 0,
tryagain_text, custdesc, custprompt, canceled);
if (*canceled)
{
xfree (pw);
write_status( STATUS_MISSING_PASSPHRASE );
return NULL;
}
}
if ( !pw || !*pw )
write_status( STATUS_MISSING_PASSPHRASE );
/* Hash the passphrase and store it in a newly allocated DEK object.
Keep a copy of the passphrase in LAST_PW for use by
get_last_passphrase(). */
dek = xmalloc_secure_clear ( sizeof *dek );
dek->algo = cipher_algo;
if ( (!pw || !*pw) && (mode == 2 || mode == 4))
dek->keylen = 0;
else
{
gpg_error_t err;
dek->keylen = openpgp_cipher_get_algo_keylen (dek->algo);
if (!(dek->keylen > 0 && dek->keylen <= DIM(dek->key)))
BUG ();
err = gcry_kdf_derive (pw, strlen (pw),
s2k->mode == 3? GCRY_KDF_ITERSALTED_S2K :
s2k->mode == 1? GCRY_KDF_SALTED_S2K :
/* */ GCRY_KDF_SIMPLE_S2K,
s2k->hash_algo, s2k->salt, 8,
S2K_DECODE_COUNT(s2k->count),
dek->keylen, dek->key);
if (err)
{
log_error ("gcry_kdf_derive failed: %s", gpg_strerror (err));
xfree (pw);
xfree (dek);
write_status( STATUS_MISSING_PASSPHRASE );
return NULL;
}
}
if (s2k_cacheid)
memcpy (dek->s2k_cacheid, s2k_cacheid, sizeof dek->s2k_cacheid);
xfree(last_pw);
last_pw = pw;
return dek;
}
/*
* Ask the GPG Agent for the passphrase.
* Mode 0: Allow cached passphrase
* 1: No cached passphrase; that is we are asking for a new passphrase
* FIXME: Only partially implemented
*
* Note that TRYAGAIN_TEXT must not be translated. If CANCELED is not
* NULL, the function does set it to 1 if the user canceled the
* operation. If CACHEID is not NULL, it will be used as the cacheID
* for the gpg-agent; if is NULL and a key fingerprint can be
* computed, this will be used as the cacheid.
*/
static char *
passphrase_get ( u32 *keyid, int mode, const char *cacheid, int repeat,
const char *tryagain_text,
const char *custom_description,
const char *custom_prompt, int *canceled)
{
int rc;
char *atext = NULL;
char *pw = NULL;
PKT_public_key *pk = xmalloc_clear( sizeof *pk );
byte fpr[MAX_FINGERPRINT_LEN];
int have_fpr = 0;
char *orig_codeset;
char *my_prompt;
char hexfprbuf[20*2+1];
const char *my_cacheid;
int check = (mode == 1);
if (canceled)
*canceled = 0;
#if MAX_FINGERPRINT_LEN < 20
#error agent needs a 20 byte fingerprint
#endif
memset (fpr, 0, MAX_FINGERPRINT_LEN );
if( keyid && get_pubkey( pk, keyid ) )
{
if (pk)
free_public_key( pk );
pk = NULL; /* oops: no key for some reason */
}
orig_codeset = i18n_switchto_utf8 ();
if (custom_description)
atext = native_to_utf8 (custom_description);
else if ( !mode && pk && keyid )
{
char *uid;
size_t uidlen;
const char *algo_name = openpgp_pk_algo_name (pk->pubkey_algo);
const char *timestr;
char *maink;
if ( !algo_name )
algo_name = "?";
#define KEYIDSTRING _(" (main key ID %s)")
maink = xmalloc ( strlen (KEYIDSTRING) + keystrlen() + 20 );
if( keyid[2] && keyid[3] && keyid[0] != keyid[2]
&& keyid[1] != keyid[3] )
sprintf( maink, KEYIDSTRING, keystr(&keyid[2]) );
else
*maink = 0;
uid = get_user_id ( keyid, &uidlen );
timestr = strtimestamp (pk->timestamp);
#undef KEYIDSTRING
#define PROMPTSTRING _("Please enter the passphrase to unlock the" \
" secret key for the OpenPGP certificate:\n" \
"\"%.*s\"\n" \
"%u-bit %s key, ID %s,\n" \
"created %s%s.\n" )
atext = xmalloc ( 100 + strlen (PROMPTSTRING)
+ uidlen + 15 + strlen(algo_name) + keystrlen()
+ strlen (timestr) + strlen (maink) );
sprintf (atext, PROMPTSTRING,
(int)uidlen, uid,
nbits_from_pk (pk), algo_name, keystr(&keyid[0]), timestr,
maink );
xfree (uid);
xfree (maink);
#undef PROMPTSTRING
{
size_t dummy;
fingerprint_from_pk( pk, fpr, &dummy );
have_fpr = 1;
}
}
else
atext = xstrdup ( _("Enter passphrase\n") );
if (!mode && cacheid)
my_cacheid = cacheid;
else if (!mode && have_fpr)
my_cacheid = bin2hex (fpr, 20, hexfprbuf);
else
my_cacheid = NULL;
if (tryagain_text)
tryagain_text = _(tryagain_text);
my_prompt = custom_prompt ? native_to_utf8 (custom_prompt): NULL;
rc = agent_get_passphrase (my_cacheid, tryagain_text, my_prompt, atext,
repeat, check, &pw);
xfree (my_prompt);
xfree (atext); atext = NULL;
i18n_switchback (orig_codeset);
if (!rc)
;
else if ( gpg_err_code (rc) == GPG_ERR_CANCELED )
{
log_info (_("cancelled by user\n") );
if (canceled)
*canceled = 1;
}
else
{
log_error (_("problem with the agent: %s\n"), gpg_strerror (rc));
/* Due to limitations in the API of the upper layers they
consider an error as no passphrase entered. This works in
most cases but not during key creation where this should
definitely not happen and let it continue without requiring a
passphrase. Given that now all the upper layers handle a
cancel correctly, we simply set the cancel flag now for all
errors from the agent. */
if (canceled)
*canceled = 1;
write_status_error ("get_passphrase", rc);
}
if (pk)
free_public_key( pk );
if (rc)
{
xfree (pw);
return NULL;
}
return pw;
}
