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|
/* app-nks.c - The Telesec NKS 2.0 card application.
* Copyright (C) 2004, 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 <http://www.gnu.org/licenses/>.
*/
#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 "i18n.h"
#include "iso7816.h"
#include "app-common.h"
#include "tlv.h"
static struct
{
int fid; /* File ID. */
int certtype; /* Type of certificate or 0 if it is not a certificate. */
int iskeypair; /* If true has the FID of the correspoding certificate. */
int issignkey; /* True if file is a key usable for signing. */
int isenckey; /* True if file is a key usable for decryption. */
} filelist[] = {
{ 0x4531, 0, 0xC000, 1, 0 },
{ 0xC000, 101 },
{ 0x4331, 100 },
{ 0x4332, 100 },
{ 0xB000, 110 },
{ 0x45B1, 0, 0xC200, 0, 1 },
{ 0xC200, 101 },
{ 0x43B1, 100 },
{ 0x43B2, 100 },
{ 0, 0 }
};
/* Read the file with FID, assume it contains a public key and return
its keygrip in the caller provided 41 byte buffer R_GRIPSTR. */
static gpg_error_t
keygripstr_from_pk_file (int slot, int fid, char *r_gripstr)
{
gpg_error_t err;
unsigned char grip[20];
unsigned char *buffer[2];
size_t buflen[2];
gcry_sexp_t sexp;
int i;
err = iso7816_select_file (slot, fid, 0, NULL, NULL);
if (err)
return err;
err = iso7816_read_record (slot, 1, 1, 0, &buffer[0], &buflen[0]);
if (err)
return err;
err = iso7816_read_record (slot, 2, 1, 0, &buffer[1], &buflen[1]);
if (err)
{
xfree (buffer[0]);
return err;
}
for (i=0; i < 2; i++)
{
/* Check that the value appears like an integer encoded as
Simple-TLV. We don't check the tag because the tests cards I
have use 1 for both, the modulus and the exponent - the
example in the documentation gives 2 for the exponent. */
if (buflen[i] < 3)
err = gpg_error (GPG_ERR_TOO_SHORT);
else if (buffer[i][1] != buflen[i]-2 )
err = gpg_error (GPG_ERR_INV_OBJ);
}
if (!err)
err = gcry_sexp_build (&sexp, NULL,
"(public-key (rsa (n %b) (e %b)))",
(int)buflen[0]-2, buffer[0]+2,
(int)buflen[1]-2, buffer[1]+2);
xfree (buffer[0]);
xfree (buffer[1]);
if (err)
return err;
if (!gcry_pk_get_keygrip (sexp, grip))
{
err = gpg_error (GPG_ERR_INTERNAL); /* i.e. RSA not supported by
libgcrypt. */
}
else
{
for (i=0; i < 20; i++)
sprintf (r_gripstr+i*2, "%02X", grip[i]);
}
gcry_sexp_release (sexp);
return err;
}
static gpg_error_t
do_learn_status (app_t app, ctrl_t ctrl)
{
gpg_error_t err;
char ct_buf[100], id_buf[100];
int i;
/* Output information about all useful objects. */
for (i=0; filelist[i].fid; i++)
{
if (filelist[i].certtype)
{
size_t len;
len = app_help_read_length_of_cert (app->slot,
filelist[i].fid, NULL);
if (len)
{
/* FIXME: We should store the length in the application's
context so that a following readcert does only need to
read that many bytes. */
sprintf (ct_buf, "%d", filelist[i].certtype);
sprintf (id_buf, "NKS-DF01.%04X", filelist[i].fid);
send_status_info (ctrl, "CERTINFO",
ct_buf, strlen (ct_buf),
id_buf, strlen (id_buf),
NULL, (size_t)0);
}
}
else if (filelist[i].iskeypair)
{
char gripstr[40+1];
err = keygripstr_from_pk_file (app->slot, filelist[i].fid, gripstr);
if (err)
log_error ("can't get keygrip from FID 0x%04X: %s\n",
filelist[i].fid, gpg_strerror (err));
else
{
sprintf (id_buf, "NKS-DF01.%04X", filelist[i].fid);
send_status_info (ctrl, "KEYPAIRINFO",
gripstr, 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. */
static gpg_error_t
do_readcert (app_t app, const char *certid,
unsigned char **cert, size_t *certlen)
{
int i, 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, "NKS-DF01.", 9) )
return gpg_error (GPG_ERR_INV_ID);
certid += 9;
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);
for (i=0; filelist[i].fid; i++)
if ((filelist[i].certtype || filelist[i].iskeypair)
&& filelist[i].fid == fid)
break;
if (!filelist[i].fid)
return gpg_error (GPG_ERR_NOT_FOUND);
/* If the requested objects is a plain public key, redirect it to
the corresponding certificate. The whole system is a bit messy
because we sometime use the key directly or let the caller
retrieve the key from the certificate. The rationale for
that is to support not-yet stored certificates. */
if (filelist[i].iskeypair)
fid = filelist[i].iskeypair;
/* 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->slot, fid, 0, NULL, NULL);
if (err)
{
log_error ("error selecting FID 0x%04X: %s\n", fid, gpg_strerror (err));
return err;
}
err = iso7816_read_binary (app->slot, 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)
{
iso7816_pininfo_t pininfo;
int rc;
/* Note that force_chv1 is never set but we do it here anyway so
that other applications may reuse this function. For example it
makes sense to set force_chv1 for German signature law cards.
NKS is very similar to the DINSIG draft standard. */
if ( app->did_chv1 && !app->force_chv1 )
return 0; /* No need to verify it again. */
memset (&pininfo, 0, sizeof pininfo);
pininfo.mode = 1;
pininfo.minlen = 6;
pininfo.maxlen = 16;
if (!opt.disable_keypad
&& !iso7816_check_keypad (app->slot, ISO7816_VERIFY, &pininfo) )
{
rc = pincb (pincb_arg,
_("||Please enter your PIN at the reader's keypad"),
NULL);
if (rc)
{
log_info (_("PIN callback returned error: %s\n"),
gpg_strerror (rc));
return rc;
}
/* Although it is possible to use a local PIN, we use the global
PIN for this application. */
rc = iso7816_verify_kp (app->slot, 0, "", 0, &pininfo);
/* Dismiss the prompt. */
pincb (pincb_arg, NULL, NULL);
}
else
{
char *pinvalue;
rc = pincb (pincb_arg, "PIN", &pinvalue);
if (rc)
{
log_info ("PIN callback returned error: %s\n", gpg_strerror (rc));
return rc;
}
/* The following limits are due to TCOS but also defined in the
NKS specs. */
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);
}
/* Although it is possible to use a local PIN, we use the global
PIN for this application. */
rc = iso7816_verify (app->slot, 0, pinvalue, strlen (pinvalue));
xfree (pinvalue);
}
if (rc)
{
if ( gpg_err_code (rc) == GPG_ERR_USE_CONDITIONS )
log_error (_("the NullPIN has not yet been changed\n"));
else
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, 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 };
int rc, i;
int fid;
unsigned char data[35]; /* Must be large enough for a SHA-1 digest
+ the largest OID _prefix above. */
if (!keyidstr || !*keyidstr)
return gpg_error (GPG_ERR_INV_VALUE);
if (indatalen != 20 && indatalen != 16 && indatalen != 35)
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, "NKS-DF01.", 9) )
return gpg_error (GPG_ERR_INV_ID);
keyidstr += 9;
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);
for (i=0; filelist[i].fid; i++)
if (filelist[i].iskeypair && filelist[i].fid == fid)
break;
if (!filelist[i].fid)
return gpg_error (GPG_ERR_NOT_FOUND);
if (!filelist[i].issignkey)
return gpg_error (GPG_ERR_INV_ID);
/* Prepare the DER object from INDATA. */
if (indatalen == 35)
{
/* Alright, the caller was so kind to send us an already
prepared DER object. Check that it is waht 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 (hashalgo == GCRY_MD_SHA1)
memcpy (data, sha1_prefix, 15);
else if (hashalgo == GCRY_MD_RMD160)
memcpy (data, rmd160_prefix, 15);
else
return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM);
memcpy (data+15, indata, indatalen);
}
rc = verify_pin (app, pincb, pincb_arg);
if (!rc)
rc = iso7816_compute_ds (app->slot, data, 35, outdata, outdatalen);
return rc;
}
/* Decrypt the data in INDATA and return the allocated result in OUTDATA.
If a PIN is required the PINCB will be used to ask for the PIN; it
should return the PIN in an allocated buffer and put it into PIN. */
static gpg_error_t
do_decipher (app_t app, const char *keyidstr,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg,
const void *indata, size_t indatalen,
unsigned char **outdata, size_t *outdatalen )
{
static const unsigned char mse_parm[] = {
0x80, 1, 0x10, /* Select algorithm RSA. */
0x84, 1, 0x81 /* Select local secret key 1 for decryption. */
};
int rc, i;
int fid;
if (!keyidstr || !*keyidstr || !indatalen)
return gpg_error (GPG_ERR_INV_VALUE);
/* Check that the provided ID is valid. This is not really needed
but we do it to to enforce correct usage by the caller. */
if (strncmp (keyidstr, "NKS-DF01.", 9) )
return gpg_error (GPG_ERR_INV_ID);
keyidstr += 9;
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);
for (i=0; filelist[i].fid; i++)
if (filelist[i].iskeypair && filelist[i].fid == fid)
break;
if (!filelist[i].fid)
return gpg_error (GPG_ERR_NOT_FOUND);
if (!filelist[i].isenckey)
return gpg_error (GPG_ERR_INV_ID);
/* Do the TCOS specific MSE. */
rc = iso7816_manage_security_env (app->slot,
0xC1, 0xB8,
mse_parm, sizeof mse_parm);
if (!rc)
rc = verify_pin (app, pincb, pincb_arg);
if (!rc)
rc = iso7816_decipher (app->slot, indata, indatalen, 0x81,
outdata, outdatalen);
return rc;
}
/* 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;
(void)ctrl;
(void)chvnostr;
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|New PIN"), &pinvalue);
if (err)
{
log_error (_("error getting new PIN: %s\n"), gpg_strerror (err));
return err;
}
err = iso7816_change_reference_data (app->slot, 0x00,
oldpin, oldpinlen,
pinvalue, strlen (pinvalue));
xfree (pinvalue);
return err;
}
/* Perform a simple verify operation. KEYIDSTR should be NULL or empty. */
static gpg_error_t
do_check_pin (app_t app, const char *keyidstr,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg)
{
(void)keyidstr;
return verify_pin (app, pincb, pincb_arg);
}
/* Select the NKS 2.0 application. */
gpg_error_t
app_select_nks (app_t app)
{
static char const aid[] = { 0xD2, 0x76, 0x00, 0x00, 0x03, 0x01, 0x02 };
int slot = app->slot;
int rc;
rc = iso7816_select_application (slot, aid, sizeof aid, 0);
if (!rc)
{
app->apptype = "NKS";
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 = do_decipher;
app->fnc.change_pin = do_change_pin;
app->fnc.check_pin = do_check_pin;
}
return rc;
}
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