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scd: Support ECC key generation. 

* scd/app-openpgp.c (get_public_key): Fix a message.
(change_keyattr_from_string, ecc_writekey): Call mpi_release sooner.
(do_genkey): Add ECC support.

--

In OpenPGP card specification 3.0, ECC is introduced.  So far, do_genkey
only supported RSA.  Since KDF spec. is needed to calculate the
fingerprint, it is hard coded in app-openpgp.c.  But it's defined by
OpenPGP ECC (RFC-6637), and card does nothing with KDF in fact.

Co-authored-by: Arnaud Fontaine <arnaud.fontaine@ssi.gouv.fr>
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
This commit is contained in:
NIIBE Yutaka 2016-10-18 22:46:37 +09:00
parent f1845f25db
commit 34439da2d6
1 changed files with 137 additions and 61 deletions
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198
scd/app-openpgp.c
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@ -1318,7 +1318,7 @@ get_public_key (app_t app, int keyno)
if (!m)
{
err = gpg_error (GPG_ERR_CARD);
log_error (_("response does not contain the EC public point\n"));
log_error (_("response does not contain the EC public key\n"));
goto leave;
}
}
@ -2847,6 +2847,7 @@ change_keyattr_from_string (app_t app,
size_t oid_len;
oidstr = openpgp_curve_to_oid (string+n, NULL);
gcry_mpi_release (oid);
if (!oidstr)
{
err = gpg_error (GPG_ERR_INV_DATA);
@ -2864,7 +2865,6 @@ change_keyattr_from_string (app_t app,
string[0] = algo;
memcpy (string+1, oidbuf+1, oid_len-1);
err = change_keyattr (app, keyno, string, oid_len, pincb, pincb_arg);
gcry_mpi_release (oid);
}
else
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
@ -3355,13 +3355,14 @@ ecc_writekey (app_t app, gpg_error_t (*pincb)(void*, const char *, char **),
if (err)
goto leave;
oidbuf = gcry_mpi_get_opaque (oid, &n);
oid_len = (n+7)/8;
if (!oidbuf)
{
err = gpg_error_from_syserror ();
gcry_mpi_release (oid);
goto leave;
}
gcry_mpi_release (oid);
oid_len = (n+7)/8;
if (app->app_local->keyattr[keyno].key_type != KEY_TYPE_ECC
|| app->app_local->keyattr[keyno].ecc.oid != oidstr
@ -3442,8 +3443,6 @@ ecc_writekey (app_t app, gpg_error_t (*pincb)(void*, const char *, char **),
ecc_q, ecc_q_len, "\x03\x01\x08\x07", (size_t)4);
leave:
if (oidbuf)
gcry_mpi_release (oid);
return err;
}
@ -3535,16 +3534,15 @@ do_genkey (app_t app, ctrl_t ctrl, const char *keynostr, unsigned int flags,
gpg_error_t err;
char numbuf[30];
unsigned char fprbuf[20];
const unsigned char *keydata, *m, *e;
unsigned char *buffer = NULL;
size_t buflen, keydatalen, mlen, elen;
const unsigned char *keydata;
size_t buflen, keydatalen;
u32 created_at;
int keyno = atoi (keynostr) - 1;
int force = (flags & 1);
time_t start_at;
int exmode;
int le_value;
unsigned int keybits;
int exmode = 0;
int le_value = 256; /* Use legacy value. */
if (keyno < 0 || keyno > 2)
return gpg_error (GPG_ERR_INV_ID);
@ -3564,34 +3562,34 @@ do_genkey (app_t app, ctrl_t ctrl, const char *keynostr, unsigned int flags,
if (err)
return err;
/* Because we send the key parameter back via status lines we need
to put a limit on the max. allowed keysize. 2048 bit will
already lead to a 527 byte long status line and thus a 4096 bit
key would exceed the Assuan line length limit. */
keybits = app->app_local->keyattr[keyno].rsa.n_bits;
if (keybits > 4096)
return gpg_error (GPG_ERR_TOO_LARGE);
if (app->app_local->keyattr[keyno].key_type == KEY_TYPE_RSA)
{
unsigned int keybits = app->app_local->keyattr[keyno].rsa.n_bits;
/* Because we send the key parameter back via status lines we need
to put a limit on the max. allowed keysize. 2048 bit will
already lead to a 527 byte long status line and thus a 4096 bit
key would exceed the Assuan line length limit. */
if (keybits > 4096)
return gpg_error (GPG_ERR_TOO_LARGE);
/* Test whether we will need extended length mode. (1900 is an
arbitrary length which for sure fits into a short apdu.) */
if (app->app_local->cardcap.ext_lc_le && keybits > 1900)
{
exmode = 1; /* Use extended length w/o a limit. */
le_value = app->app_local->extcap.max_rsp_data;
/* No need to check le_value because it comes from a 16 bit
value and thus can't create an overflow on a 32 bit
system. */
}
}
/* Prepare for key generation by verifying the Admin PIN. */
err = verify_chv3 (app, pincb, pincb_arg);
if (err)
goto leave;
return err;
/* Test whether we will need extended length mode. (1900 is an
arbitrary length which for sure fits into a short apdu.) */
if (app->app_local->cardcap.ext_lc_le && keybits > 1900)
{
exmode = 1; /* Use extended length w/o a limit. */
le_value = app->app_local->extcap.max_rsp_data;
/* No need to check le_value because it comes from a 16 bit
value and thus can't create an overflow on a 32 bit
system. */
}
else
{
exmode = 0;
le_value = 256; /* Use legacy value. */
}
log_info (_("please wait while key is being generated ...\n"));
start_at = time (NULL);
@ -3601,9 +3599,8 @@ do_genkey (app_t app, ctrl_t ctrl, const char *keynostr, unsigned int flags,
2, le_value, &buffer, &buflen);
if (err)
{
err = gpg_error (GPG_ERR_CARD);
log_error (_("generating key failed\n"));
goto leave;
return gpg_error (GPG_ERR_CARD);
}
{
@ -3621,38 +3618,117 @@ do_genkey (app_t app, ctrl_t ctrl, const char *keynostr, unsigned int flags,
goto leave;
}
m = find_tlv (keydata, keydatalen, 0x0081, &mlen);
if (!m)
{
err = gpg_error (GPG_ERR_CARD);
log_error (_("response does not contain the RSA modulus\n"));
goto leave;
}
/* log_printhex ("RSA n:", m, mlen); */
send_key_data (ctrl, "n", m, mlen);
e = find_tlv (keydata, keydatalen, 0x0082, &elen);
if (!e)
{
err = gpg_error (GPG_ERR_CARD);
log_error (_("response does not contain the RSA public exponent\n"));
goto leave;
}
/* log_printhex ("RSA e:", e, elen); */
send_key_data (ctrl, "e", e, elen);
created_at = (u32)(createtime? createtime : gnupg_get_time ());
sprintf (numbuf, "%u", created_at);
send_status_info (ctrl, "KEY-CREATED-AT",
numbuf, (size_t)strlen(numbuf), NULL, 0);
for (; mlen && !*m; mlen--, m++) /* strip leading zeroes */
;
for (; elen && !*e; elen--, e++) /* strip leading zeroes */
;
if (app->app_local->keyattr[keyno].key_type == KEY_TYPE_RSA)
{
const unsigned char *m, *e;
size_t mlen, elen;
m = find_tlv (keydata, keydatalen, 0x0081, &mlen);
if (!m)
{
err = gpg_error (GPG_ERR_CARD);
log_error (_("response does not contain the RSA modulus\n"));
goto leave;
}
/* log_printhex ("RSA n:", m, mlen); */
send_key_data (ctrl, "n", m, mlen);
e = find_tlv (keydata, keydatalen, 0x0082, &elen);
if (!e)
{
err = gpg_error (GPG_ERR_CARD);
log_error (_("response does not contain the RSA public exponent\n"));
goto leave;
}
/* log_printhex ("RSA e:", e, elen); */
send_key_data (ctrl, "e", e, elen);
for (; mlen && !*m; mlen--, m++) /* strip leading zeroes */
;
for (; elen && !*e; elen--, e++) /* strip leading zeroes */
;
err = store_fpr (app, keyno, created_at, fprbuf, PUBKEY_ALGO_RSA,
m, mlen, e, elen);
}
else if (app->app_local->keyattr[keyno].key_type == KEY_TYPE_ECC)
{
const unsigned char *ecc_q;
size_t ecc_q_len;
gcry_mpi_t oid;
int n;
const unsigned char *oidbuf;
size_t oid_len;
int algo;
ecc_q = find_tlv (keydata, keydatalen, 0x0086, &ecc_q_len);
if (!ecc_q)
{
err = gpg_error (GPG_ERR_CARD);
log_error (_("response does not contain the EC public key\n"));
goto leave;
}
err = openpgp_oid_from_str (app->app_local->keyattr[keyno].ecc.oid, &oid);
if (err)
goto leave;
oidbuf = gcry_mpi_get_opaque (oid, &n);
if (!oidbuf)
{
err = gpg_error_from_syserror ();
gcry_mpi_release (oid);
goto leave;
}
gcry_mpi_release (oid);
oid_len = (n+7)/8;
if ((app->app_local->keyattr[keyno].ecc.flags & ECC_FLAG_DJB_TWEAK))
{ /* Prepend 0x40 prefix. */
unsigned char *q = xtrymalloc (ecc_q_len + 1);
if (!q)
{
err = gpg_error_from_syserror ();
goto leave;
}
*q = 0x40;
memcpy (q+1, ecc_q, ecc_q_len);
send_key_data (ctrl, "q", q, ecc_q_len + 1);
xfree (q);
}
else
{
/* strip leading zeroes */
for (; ecc_q_len && !*ecc_q; ecc_q_len--, ecc_q++)
;
send_key_data (ctrl, "q", ecc_q, ecc_q_len);
}
send_key_data (ctrl, "curve", oidbuf, oid_len);
if (keyno == 1)
{
send_key_data (ctrl, "kdf", "\x03\x01\x08\x07", (size_t)4);
algo = PUBKEY_ALGO_ECDH;
}
else
{
if ((app->app_local->keyattr[keyno].ecc.flags & ECC_FLAG_DJB_TWEAK))
algo = PUBKEY_ALGO_EDDSA;
else
algo = PUBKEY_ALGO_ECDSA;
}
err = store_fpr (app, keyno, created_at, fprbuf, algo, oidbuf, oid_len,
ecc_q, ecc_q_len, "\x03\x01\x08\x07", (size_t)4);
}
err = store_fpr (app, keyno, created_at, fprbuf, PUBKEY_ALGO_RSA,
m, mlen, e, elen);
if (err)
goto leave;
send_fpr_if_not_null (ctrl, "KEY-FPR", -1, fprbuf);