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gnupg/scd/app-dinsig.c
Werner Koch fbf97a7856
scd: First changes to implement a PIN cache. 
* scd/command.c (pincache_put): New.  Uses a dummy key for now.
(pincache_get): New.
* scd/app.c (select_application): Flush the PIN cache.
(scd_update_reader_status_file): Ditto.
(maybe_switch_app): Call the new prep_reselect function.
(app_write_learn_status): Ditto.
* scd/app-openpgp.c (cache_pin): New helper to cache a PIN.
(verify_chv2): Call it.
(verify_chv3): Call it.
(clear_chv_status): Call it.
(do_change_pin): Call it.

* scd/app-common.h (struct app_ctx_s): Add function 'prep_select'.
* scd/app-openpgp.c (do_prep_reselect): New stub function.
(app_select_openpgp): Set new stub function.
* scd/app-piv.c (do_prep_reselect): New stub function.
(app_select_piv): Set new stub function.

* scd/app-common.h (struct app_ctx_s): Add parameter ctrl to setattr,
sign, auth, decipher, and check_pin.  Change all implementations and
callers to pass such a parameter.
--

This is work in progress.

Signed-off-by: Werner Koch <wk@gnupg.org>
2020-01-07 18:45:33 +01:00

580 lines
18 KiB
C
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/* app-dinsig.c - The DINSIG (DIN V 66291-1) card application.
* Copyright (C) 2002, 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
/* The German signature law and its bylaw (SigG and SigV) is currently
used with an interface specification described in DIN V 66291-1.
The AID to be used is: 'D27600006601'.
The file IDs for certificates utilize the generic format:
Cxyz
C being the hex digit 'C' (12).
x being the service indicator:
'0' := SigG conform digital signature.
'1' := entity authentication.
'2' := key encipherment.
'3' := data encipherment.
'4' := key agreement.
other values are reserved for future use.
y being the security environment number using '0' for cards
not supporting a SE number.
z being the certificate type:
'0' := C.CH (base certificate of card holder) or C.ICC.
'1' .. '7' := C.CH (business or professional certificate
of card holder.
'8' .. 'D' := C.CA (certificate of a CA issue by the Root-CA).
'E' := C.RCA (self certified certificate of the Root-CA).
'F' := reserved.
The file IDs used by default are:
'1F00' EF.SSD (security service descriptor). [o,o]
'2F02' EF.GDO (global data objects) [m,m]
'A000' EF.PROT (signature log). Cyclic file with 20 records of 53 byte.
Read and update after user authentication. [o,o]
'B000' EF.PK.RCA.DS (public keys of Root-CA). Size is 512b or size
of keys. [m (unless a 'C00E' is present),m]
'B001' EF.PK.CA.DS (public keys of CAs). Size is 512b or size
of keys. [o,o]
'C00n' EF.C.CH.DS (digital signature certificate of card holder)
with n := 0 .. 7. Size is 2k or size of cert. Read and
update allowed after user authentication. [m,m]
'C00m' EF.C.CA.DS (digital signature certificate of CA)
with m := 8 .. E. Size is 1k or size of cert. Read always
allowed, update after user authentication. [o,o]
'C100' EF.C.ICC.AUT (AUT certificate of ICC) [o,m]
'C108' EF.C.CA.AUT (AUT certificate of CA) [o,m]
'D000' EF.DM (display message) [-,m]
The letters in brackets indicate optional or mandatory files: The
first for card terminals under full control and the second for
"business" card terminals.
*/
#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <time.h>
#include "scdaemon.h"
#include "../common/i18n.h"
#include "iso7816.h"
#include "../common/tlv.h"
static gpg_error_t
do_learn_status (app_t app, ctrl_t ctrl, unsigned int flags)
{
gpg_error_t err;
char ct_buf[100], id_buf[100];
char hexkeygrip[41];
size_t len, certoff;
unsigned char *der;
size_t derlen;
ksba_cert_t cert;
int fid;
(void)flags;
/* Return the certificate of the card holder. */
fid = 0xC000;
len = app_help_read_length_of_cert (app_get_slot (app), fid, &certoff);
if (!len)
return 0; /* Card has not been personalized. */
sprintf (ct_buf, "%d", 101);
sprintf (id_buf, "DINSIG.%04X", fid);
send_status_info (ctrl, "CERTINFO",
ct_buf, strlen (ct_buf),
id_buf, strlen (id_buf),
NULL, (size_t)0);
/* Now we need to read the certificate, so that we can get the
public key out of it. */
err = iso7816_read_binary (app_get_slot (app), certoff, len-certoff,
&der, &derlen);
if (err)
{
log_info ("error reading entire certificate from FID 0x%04X: %s\n",
fid, gpg_strerror (err));
return 0;
}
err = ksba_cert_new (&cert);
if (err)
{
xfree (der);
return err;
}
err = ksba_cert_init_from_mem (cert, der, derlen);
xfree (der); der = NULL;
if (err)
{
log_error ("failed to parse the certificate at FID 0x%04X: %s\n",
fid, gpg_strerror (err));
ksba_cert_release (cert);
return err;
}
err = app_help_get_keygrip_string (cert, hexkeygrip);
if (err)
{
log_error ("failed to calculate the keygrip for FID 0x%04X\n", fid);
ksba_cert_release (cert);
return gpg_error (GPG_ERR_CARD);
}
ksba_cert_release (cert);
sprintf (id_buf, "DINSIG.%04X", fid);
send_status_info (ctrl, "KEYPAIRINFO",
hexkeygrip, 40,
id_buf, strlen (id_buf),
NULL, (size_t)0);
return 0;
}
/* Read the certificate with id CERTID (as returned by learn_status in
the CERTINFO status lines) and return it in the freshly allocated
buffer put into CERT and the length of the certificate put into
CERTLEN.
FIXME: This needs some cleanups and caching with do_learn_status.
*/
static gpg_error_t
do_readcert (app_t app, const char *certid,
unsigned char **cert, size_t *certlen)
{
int fid;
gpg_error_t err;
unsigned char *buffer;
const unsigned char *p;
size_t buflen, n;
int class, tag, constructed, ndef;
size_t totobjlen, objlen, hdrlen;
int rootca = 0;
*cert = NULL;
*certlen = 0;
if (strncmp (certid, "DINSIG.", 7) )
return gpg_error (GPG_ERR_INV_ID);
certid += 7;
if (!hexdigitp (certid) || !hexdigitp (certid+1)
|| !hexdigitp (certid+2) || !hexdigitp (certid+3)
|| certid[4])
return gpg_error (GPG_ERR_INV_ID);
fid = xtoi_4 (certid);
if (fid != 0xC000 )
return gpg_error (GPG_ERR_NOT_FOUND);
/* Read the entire file. fixme: This could be optimized by first
reading the header to figure out how long the certificate
actually is. */
err = iso7816_select_file (app_get_slot (app), fid, 0);
if (err)
{
log_error ("error selecting FID 0x%04X: %s\n", fid, gpg_strerror (err));
return err;
}
err = iso7816_read_binary (app_get_slot (app), 0, 0, &buffer, &buflen);
if (err)
{
log_error ("error reading certificate from FID 0x%04X: %s\n",
fid, gpg_strerror (err));
return err;
}
if (!buflen || *buffer == 0xff)
{
log_info ("no certificate contained in FID 0x%04X\n", fid);
err = gpg_error (GPG_ERR_NOT_FOUND);
goto leave;
}
/* Now figure something out about the object. */
p = buffer;
n = buflen;
err = parse_ber_header (&p, &n, &class, &tag, &constructed,
&ndef, &objlen, &hdrlen);
if (err)
goto leave;
if ( class == CLASS_UNIVERSAL && tag == TAG_SEQUENCE && constructed )
;
else if ( class == CLASS_UNIVERSAL && tag == TAG_SET && constructed )
rootca = 1;
else
return gpg_error (GPG_ERR_INV_OBJ);
totobjlen = objlen + hdrlen;
assert (totobjlen <= buflen);
err = parse_ber_header (&p, &n, &class, &tag, &constructed,
&ndef, &objlen, &hdrlen);
if (err)
goto leave;
if (rootca)
;
else if (class == CLASS_UNIVERSAL && tag == TAG_OBJECT_ID && !constructed)
{
const unsigned char *save_p;
/* The certificate seems to be contained in a userCertificate
container. Skip this and assume the following sequence is
the certificate. */
if (n < objlen)
{
err = gpg_error (GPG_ERR_INV_OBJ);
goto leave;
}
p += objlen;
n -= objlen;
save_p = p;
err = parse_ber_header (&p, &n, &class, &tag, &constructed,
&ndef, &objlen, &hdrlen);
if (err)
goto leave;
if ( !(class == CLASS_UNIVERSAL && tag == TAG_SEQUENCE && constructed) )
return gpg_error (GPG_ERR_INV_OBJ);
totobjlen = objlen + hdrlen;
assert (save_p + totobjlen <= buffer + buflen);
memmove (buffer, save_p, totobjlen);
}
*cert = buffer;
buffer = NULL;
*certlen = totobjlen;
leave:
xfree (buffer);
return err;
}
/* Verify the PIN if required. */
static gpg_error_t
verify_pin (app_t app,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg)
{
const char *s;
int rc;
pininfo_t pininfo;
if ( app->did_chv1 && !app->force_chv1 )
return 0; /* No need to verify it again. */
memset (&pininfo, 0, sizeof pininfo);
pininfo.fixedlen = -1;
pininfo.minlen = 6;
pininfo.maxlen = 8;
if (!opt.disable_pinpad
&& !iso7816_check_pinpad (app_get_slot (app), ISO7816_VERIFY, &pininfo) )
{
rc = pincb (pincb_arg,
_("||Please enter your PIN at the reader's pinpad"),
NULL);
if (rc)
{
log_info (_("PIN callback returned error: %s\n"),
gpg_strerror (rc));
return rc;
}
rc = iso7816_verify_kp (app_get_slot (app), 0x81, &pininfo);
/* Dismiss the prompt. */
pincb (pincb_arg, NULL, NULL);
}
else /* No Pinpad. */
{
char *pinvalue;
rc = pincb (pincb_arg, "PIN", &pinvalue);
if (rc)
{
log_info ("PIN callback returned error: %s\n", gpg_strerror (rc));
return rc;
}
/* We require the PIN to be at least 6 and at max 8 bytes.
According to the specs, this should all be ASCII. */
for (s=pinvalue; digitp (s); s++)
;
if (*s)
{
log_error ("Non-numeric digits found in PIN\n");
xfree (pinvalue);
return gpg_error (GPG_ERR_BAD_PIN);
}
if (strlen (pinvalue) < pininfo.minlen)
{
log_error ("PIN is too short; minimum length is %d\n",
pininfo.minlen);
xfree (pinvalue);
return gpg_error (GPG_ERR_BAD_PIN);
}
else if (strlen (pinvalue) > pininfo.maxlen)
{
log_error ("PIN is too large; maximum length is %d\n",
pininfo.maxlen);
xfree (pinvalue);
return gpg_error (GPG_ERR_BAD_PIN);
}
rc = iso7816_verify (app_get_slot (app), 0x81,
pinvalue, strlen (pinvalue));
if (gpg_err_code (rc) == GPG_ERR_INV_VALUE)
{
/* We assume that ISO 9564-1 encoding is used and we failed
because the first nibble we passed was 3 and not 2. DIN
says something about looking up such an encoding in the
SSD but I was not able to find any tag relevant to
this. */
char paddedpin[8];
int i, ndigits;
for (ndigits=0, s=pinvalue; *s; ndigits++, s++)
;
i = 0;
paddedpin[i++] = 0x20 | (ndigits & 0x0f);
for (s=pinvalue; i < sizeof paddedpin && *s && s[1]; s = s+2 )
paddedpin[i++] = (((*s - '0') << 4) | ((s[1] - '0') & 0x0f));
if (i < sizeof paddedpin && *s)
paddedpin[i++] = (((*s - '0') << 4) | 0x0f);
while (i < sizeof paddedpin)
paddedpin[i++] = 0xff;
rc = iso7816_verify (app_get_slot (app), 0x81,
paddedpin, sizeof paddedpin);
}
xfree (pinvalue);
}
if (rc)
{
log_error ("verify PIN failed\n");
return rc;
}
app->did_chv1 = 1;
return 0;
}
/* Create the signature and return the allocated result in OUTDATA.
If a PIN is required the PINCB will be used to ask for the PIN;
that callback should return the PIN in an allocated buffer and
store that in the 3rd argument. */
static gpg_error_t
do_sign (app_t app, ctrl_t ctrl, const char *keyidstr, int hashalgo,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg,
const void *indata, size_t indatalen,
unsigned char **outdata, size_t *outdatalen )
{
static unsigned char sha1_prefix[15] = /* Object ID is 1.3.14.3.2.26 */
{ 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03,
0x02, 0x1a, 0x05, 0x00, 0x04, 0x14 };
static unsigned char rmd160_prefix[15] = /* Object ID is 1.3.36.3.2.1 */
{ 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x24, 0x03,
0x02, 0x01, 0x05, 0x00, 0x04, 0x14 };
static unsigned char sha256_prefix[19] = /* OID is 2.16.840.1.101.3.4.2.1 */
{ 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86,
0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05,
0x00, 0x04, 0x20 };
int rc;
int fid;
unsigned char data[19+32]; /* Must be large enough for a SHA-256 digest
+ the largest OID _prefix above. */
int datalen;
(void)ctrl;
if (!keyidstr || !*keyidstr)
return gpg_error (GPG_ERR_INV_VALUE);
if (indatalen != 20 && indatalen != 16 && indatalen != 32
&& indatalen != (15+20) && indatalen != (19+32))
return gpg_error (GPG_ERR_INV_VALUE);
/* Check that the provided ID is valid. This is not really needed
but we do it to enforce correct usage by the caller. */
if (strncmp (keyidstr, "DINSIG.", 7) )
return gpg_error (GPG_ERR_INV_ID);
keyidstr += 7;
if (!hexdigitp (keyidstr) || !hexdigitp (keyidstr+1)
|| !hexdigitp (keyidstr+2) || !hexdigitp (keyidstr+3)
|| keyidstr[4])
return gpg_error (GPG_ERR_INV_ID);
fid = xtoi_4 (keyidstr);
if (fid != 0xC000)
return gpg_error (GPG_ERR_NOT_FOUND);
/* Prepare the DER object from INDATA. */
datalen = 35;
if (indatalen == 15+20)
{
/* Alright, the caller was so kind to send us an already
prepared DER object. Check that it is what we want and that
it matches the hash algorithm. */
if (hashalgo == GCRY_MD_SHA1 && !memcmp (indata, sha1_prefix, 15))
;
else if (hashalgo == GCRY_MD_RMD160 && !memcmp (indata, rmd160_prefix,15))
;
else
return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM);
memcpy (data, indata, indatalen);
}
else if (indatalen == 19+32)
{
/* Alright, the caller was so kind to send us an already
prepared DER object. Check that it is what we want and that
it matches the hash algorithm. */
datalen = indatalen;
if (hashalgo == GCRY_MD_SHA256 && !memcmp (indata, sha256_prefix, 19))
;
else if (hashalgo == GCRY_MD_SHA1 && !memcmp (indata, sha256_prefix, 19))
{
/* Fixme: This is a kludge. A better solution is not to use
SHA1 as default but use an autodetection. However this
needs changes in all app-*.c */
datalen = indatalen;
}
else
return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM);
memcpy (data, indata, indatalen);
}
else
{
int len = 15;
if (hashalgo == GCRY_MD_SHA1)
memcpy (data, sha1_prefix, len);
else if (hashalgo == GCRY_MD_RMD160)
memcpy (data, rmd160_prefix, len);
else if (hashalgo == GCRY_MD_SHA256)
{
len = 19;
datalen = len + indatalen;
memcpy (data, sha256_prefix, len);
}
else
return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM);
memcpy (data+len, indata, indatalen);
}
rc = verify_pin (app, pincb, pincb_arg);
if (!rc)
rc = iso7816_compute_ds (app_get_slot (app), 0, data, datalen, 0,
outdata, outdatalen);
return rc;
}
#if 0
#warning test function - works but may brick your card
/* Handle the PASSWD command. CHVNOSTR is currently ignored; we
always use VHV0. RESET_MODE is not yet implemented. */
static gpg_error_t
do_change_pin (app_t app, ctrl_t ctrl, const char *chvnostr,
unsigned int flags,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg)
{
gpg_error_t err;
char *pinvalue;
const char *oldpin;
size_t oldpinlen;
if ((flags & APP_CHANGE_FLAG_RESET))
return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
if ((flags & APP_CHANGE_FLAG_NULLPIN))
{
/* With the nullpin flag, we do not verify the PIN - it would fail
if the Nullpin is still set. */
oldpin = "\0\0\0\0\0";
oldpinlen = 6;
}
else
{
err = verify_pin (app, pincb, pincb_arg);
if (err)
return err;
oldpin = NULL;
oldpinlen = 0;
}
/* TRANSLATORS: Do not translate the "|*|" prefixes but
keep it at the start of the string. We need this elsewhere
to get some infos on the string. */
err = pincb (pincb_arg, _("|N|Initial New PIN"), &pinvalue);
if (err)
{
log_error (_("error getting new PIN: %s\n"), gpg_strerror (err));
return err;
}
err = iso7816_change_reference_data (app_get_slot (app), 0x81,
oldpin, oldpinlen,
pinvalue, strlen (pinvalue));
xfree (pinvalue);
return err;
}
#endif /*0*/
/* Select the DINSIG application on the card in SLOT. This function
must be used before any other DINSIG application functions. */
gpg_error_t
app_select_dinsig (app_t app)
{
static char const aid[] = { 0xD2, 0x76, 0x00, 0x00, 0x66, 0x01 };
int slot = app_get_slot (app);
int rc;
rc = iso7816_select_application (slot, aid, sizeof aid, 0);
if (!rc)
{
app->apptype = APPTYPE_DINSIG;
app->fnc.prep_reselect = NULL;
app->fnc.reselect = NULL;
app->fnc.learn_status = do_learn_status;
app->fnc.readcert = do_readcert;
app->fnc.getattr = NULL;
app->fnc.setattr = NULL;
app->fnc.genkey = NULL;
app->fnc.sign = do_sign;
app->fnc.auth = NULL;
app->fnc.decipher = NULL;
app->fnc.change_pin = NULL /*do_change_pin*/;
app->fnc.check_pin = NULL;
app->force_chv1 = 1;
}
return rc;
}
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