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gnupg/scd/app-piv.c

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/* app-piv.c - The OpenPGP card application.
* Copyright (C) 2019 g10 Code GmbH
*
* 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/>.
*/
/* Some notes:
* - Specs for PIV are at http://dx.doi.org/10.6028/NIST.SP.800-73-4
*
*/
#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <time.h>
#include "scdaemon.h"
#include "../common/util.h"
#include "../common/i18n.h"
#include "iso7816.h"
#include "app-common.h"
#include "../common/tlv.h"
#include "../common/host2net.h"
#include "apdu.h" /* We use apdu_send_direct. */
#define PIV_ALGORITHM_3DES_ECB_0 0x00
#define PIV_ALGORITHM_2DES_ECB 0x01
#define PIV_ALGORITHM_2DES_CBC 0x02
#define PIV_ALGORITHM_3DES_ECB 0x03
#define PIV_ALGORITHM_3DES_CBC 0x04
#define PIV_ALGORITHM_RSA 0x07
#define PIV_ALGORITHM_AES128_ECB 0x08
#define PIV_ALGORITHM_AES128_CBC 0x09
#define PIV_ALGORITHM_AES192_ECB 0x0A
#define PIV_ALGORITHM_AES192_CBC 0x0B
#define PIV_ALGORITHM_AES256_ECB 0x0C
#define PIV_ALGORITHM_AES256_CBC 0x0D
#define PIV_ALGORITHM_ECC_P256 0x11
#define PIV_ALGORITHM_ECC_P384 0x14
/* A table describing the DOs of a PIV card. */
struct data_object_s
{
unsigned int tag;
unsigned int mandatory:1;
unsigned int acr_contact:2; /* 0=always, 1=VCI, 2=PIN, 3=PINorOCC */
unsigned int acr_contactless:2; /* 0=always, 1=VCI, 2=VCIandPIN,
3=VCIand(PINorOCC) */
unsigned int binary:1; /* Data is not human readable. */
unsigned int dont_cache:1; /* Data item will not be cached. */
unsigned int flush_on_error:1; /* Flush cached item on error. */
unsigned int keypair:1; /* Has a public key for a keypair. */
char keyref[3]; /* The key reference. */
char *oidsuffix; /* Suffix of the OID, prefix is "2.16.840.1.101.3.7." */
char *desc; /* Description of the DO. */
};
typedef struct data_object_s *data_object_t;
static struct data_object_s data_objects[] = {
{ 0x5FC107, 1, 0,1, 1, 0,0, 0, "", "1.219.0", "Card Capability Container"},
{ 0x5FC102, 1, 0,0, 1, 0,0, 0, "", "2.48.0", "Cardholder Unique Id" },
{ 0x5FC105, 1, 0,1, 1, 0,0, 1, "9A", "2.1.1", "Cert PIV Authentication" },
{ 0x5FC103, 1, 2,2, 1, 0,0, 0, "", "2.96.16", "Cardholder Fingerprints" },
{ 0x5FC106, 1, 0,1, 1, 0,0, 0, "", "2.144.0", "Security Object" },
{ 0x5FC108, 1, 2,2, 1, 0,0, 0, "", "2.96.48", "Cardholder Facial Image" },
{ 0x5FC101, 1, 0,0, 1, 0,0, 1, "9E", "2.5.0", "Cert Card Authentication"},
{ 0x5FC10A, 0, 0,1, 1, 0,0, 1, "9C", "2.1.0", "Cert Digital Signature" },
{ 0x5FC10B, 0, 0,1, 1, 0,0, 1, "9D", "2.1.2", "Cert Key Management" },
{ 0x5FC109, 0, 3,3, 0, 0,0, 0, "", "2.48.1", "Printed Information" },
{ 0x7E, 0, 0,0, 1, 0,0, 0, "", "2.96.80", "Discovery Object" },
{ 0x5FC10C, 0, 0,1, 1, 0,0, 0, "", "2.96.96", "Key History Object" },
{ 0x5FC10D, 0, 0,1, 1, 0,0, 0, "82", "2.16.1", "Retired Cert Key Mgm 1" },
{ 0x5FC10E, 0, 0,1, 1, 0,0, 0, "83", "2.16.2", "Retired Cert Key Mgm 2" },
{ 0x5FC10F, 0, 0,1, 1, 0,0, 0, "84", "2.16.3", "Retired Cert Key Mgm 3" },
{ 0x5FC110, 0, 0,1, 1, 0,0, 0, "85", "2.16.4", "Retired Cert Key Mgm 4" },
{ 0x5FC111, 0, 0,1, 1, 0,0, 0, "86", "2.16.5", "Retired Cert Key Mgm 5" },
{ 0x5FC112, 0, 0,1, 1, 0,0, 0, "87", "2.16.6", "Retired Cert Key Mgm 6" },
{ 0x5FC113, 0, 0,1, 1, 0,0, 0, "88", "2.16.7", "Retired Cert Key Mgm 7" },
{ 0x5FC114, 0, 0,1, 1, 0,0, 0, "89", "2.16.8", "Retired Cert Key Mgm 8" },
{ 0x5FC115, 0, 0,1, 1, 0,0, 0, "8A", "2.16.9", "Retired Cert Key Mgm 9" },
{ 0x5FC116, 0, 0,1, 1, 0,0, 0, "8B", "2.16.10", "Retired Cert Key Mgm 10" },
{ 0x5FC117, 0, 0,1, 1, 0,0, 0, "8C", "2.16.11", "Retired Cert Key Mgm 11" },
{ 0x5FC118, 0, 0,1, 1, 0,0, 0, "8D", "2.16.12", "Retired Cert Key Mgm 12" },
{ 0x5FC119, 0, 0,1, 1, 0,0, 0, "8E", "2.16.13", "Retired Cert Key Mgm 13" },
{ 0x5FC11A, 0, 0,1, 1, 0,0, 0, "8F", "2.16.14", "Retired Cert Key Mgm 14" },
{ 0x5FC11B, 0, 0,1, 1, 0,0, 0, "90", "2.16.15", "Retired Cert Key Mgm 15" },
{ 0x5FC11C, 0, 0,1, 1, 0,0, 0, "91", "2.16.16", "Retired Cert Key Mgm 16" },
{ 0x5FC11D, 0, 0,1, 1, 0,0, 0, "92", "2.16.17", "Retired Cert Key Mgm 17" },
{ 0x5FC11E, 0, 0,1, 1, 0,0, 0, "93", "2.16.18", "Retired Cert Key Mgm 18" },
{ 0x5FC11F, 0, 0,1, 1, 0,0, 0, "94", "2.16.19", "Retired Cert Key Mgm 19" },
{ 0x5FC120, 0, 0,1, 1, 0,0, 0, "95", "2.16.20", "Retired Cert Key Mgm 20" },
{ 0x5FC121, 0, 2,2, 1, 0,0, 0, "", "2.16.21", "Cardholder Iris Images" },
{ 0x7F61, 0, 0,0, 1, 0,0, 0, "", "2.16.22", "BIT Group Template" },
{ 0x5FC122, 0, 0,0, 1, 0,0, 0, "", "2.16.23", "SM Cert Signer" },
{ 0x5FC123, 0, 3,3, 1, 0,0, 0, "", "2.16.24", "Pairing Code Ref Data" },
{ 0 }
/* Other key reference values without a tag:
* "00" Global PIN (not cleared by application switching)
* "04" PIV Secure Messaging Key
* "80" PIV Application PIN
* "81" PIN Unblocking Key
* "96" Primary Finger OCC
* "97" Secondary Finger OCC
* "98" Pairing Code
* "9B" PIV Card Application Administration Key
*/
};
/* One cache item for DOs. */
struct cache_s {
struct cache_s *next;
int tag;
size_t length;
unsigned char data[1];
};
/* Object with application specific data. */
struct app_local_s {
/* A linked list with cached DOs. */
struct cache_s *cache;
/* Various flags. */
struct
{
unsigned int dummy:1;
} flags;
};
/***** Local prototypes *****/
static gpg_error_t get_keygrip_by_tag (app_t app, unsigned int tag,
char **r_keygripstr);
/* Deconstructor. */
static void
do_deinit (app_t app)
{
if (app && app->app_local)
{
struct cache_s *c, *c2;
for (c = app->app_local->cache; c; c = c2)
{
c2 = c->next;
xfree (c);
}
xfree (app->app_local);
app->app_local = NULL;
}
}
/* Wrapper around iso7816_get_data which first tries to get the data
* from the cache. With GET_IMMEDIATE passed as true, the cache is
* bypassed. The tag-53 container is also removed. */
static gpg_error_t
get_cached_data (app_t app, int tag,
unsigned char **result, size_t *resultlen,
int get_immediate)
{
gpg_error_t err;
int i;
unsigned char *p;
const unsigned char *s;
size_t len, n;
struct cache_s *c;
*result = NULL;
*resultlen = 0;
if (!get_immediate)
{
for (c=app->app_local->cache; c; c = c->next)
if (c->tag == tag)
{
if(c->length)
{
p = xtrymalloc (c->length);
if (!p)
return gpg_error_from_syserror ();
memcpy (p, c->data, c->length);
*result = p;
}
*resultlen = c->length;
return 0;
}
}
err = iso7816_get_data_odd (app->slot, 0, tag, &p, &len);
if (err)
return err;
/* Unless the Discovery Object or the BIT Group Template is
* requested, remove the outer container.
* (SP800-73.4 Part 2, section 3.1.2) */
if (tag == 0x7E || tag == 0x7F61)
;
else if (len && *p == 0x53 && (s = find_tlv (p, len, 0x53, &n)))
{
memmove (p, s, n);
len = n;
}
if (len)
*result = p;
*resultlen = len;
/* Check whether we should cache this object. */
if (get_immediate)
return 0;
for (i=0; data_objects[i].tag; i++)
if (data_objects[i].tag == tag)
{
if (data_objects[i].dont_cache)
return 0;
break;
}
/* Okay, cache it. */
for (c=app->app_local->cache; c; c = c->next)
log_assert (c->tag != tag);
c = xtrymalloc (sizeof *c + len);
if (c)
{
if (len)
memcpy (c->data, p, len);
else
xfree (p);
c->length = len;
c->tag = tag;
c->next = app->app_local->cache;
app->app_local->cache = c;
}
return 0;
}
/* Get the DO identified by TAG from the card in SLOT and return a
* buffer with its content in RESULT and NBYTES. The return value is
* NULL if not found or a pointer which must be used to release the
* buffer holding value. */
static void *
get_one_do (app_t app, int tag, unsigned char **result, size_t *nbytes,
int *r_err)
{
gpg_error_t err;
int i;
unsigned char *buffer;
size_t buflen;
unsigned char *value;
size_t valuelen;
gpg_error_t dummyerr;
if (!r_err)
r_err = &dummyerr;
*result = NULL;
*nbytes = 0;
*r_err = 0;
for (i=0; data_objects[i].tag && data_objects[i].tag != tag; i++)
;
value = NULL;
err = gpg_error (GPG_ERR_ENOENT);
if (!value) /* Not in a constructed DO, try simple. */
{
err = get_cached_data (app, tag, &buffer, &buflen,
data_objects[i].dont_cache);
if (!err)
{
value = buffer;
valuelen = buflen;
}
}
if (!err)
{
*nbytes = valuelen;
*result = value;
return buffer;
}
*r_err = err;
return NULL;
}
static void
dump_all_do (int slot)
{
gpg_error_t err;
int i;
unsigned char *buffer;
size_t buflen;
for (i=0; data_objects[i].tag; i++)
{
/* We don't try extended length APDU because such large DO would
be pretty useless in a log file. */
err = iso7816_get_data_odd (slot, 0, data_objects[i].tag,
&buffer, &buflen);
if (err)
{
if (gpg_err_code (err) == GPG_ERR_ENOENT
&& !data_objects[i].mandatory)
;
else
log_info ("DO '%s' not available: %s\n",
data_objects[i].desc, gpg_strerror (err));
}
else
{
if (data_objects[i].binary)
{
log_info ("DO '%s': ", data_objects[i].desc);
if (buflen > 16 && opt.verbose < 2)
{
log_printhex (buffer, 16, NULL);
log_printf ("[...]\n");
}
else
log_printhex (buffer, buflen, "");
}
else
log_info ("DO '%s': '%.*s'\n",
data_objects[i].desc,
(int)buflen, buffer);
}
xfree (buffer); buffer = NULL;
}
}
/* Return an allocated string with the serial number in a format to be
* show to the user. With FAILMODE is true return NULL if such an
* abbreviated S/N is not available, else return the full serial
* number as a hex string. May return NULL on malloc problem. */
static char *
get_dispserialno (app_t app, int failmode)
{
char *result;
if (app->serialno && app->serialnolen == 3+1+4
&& !memcmp (app->serialno, "\xff\x02\x00", 3))
{
/* This is a 4 byte S/N of a Yubikey which seems to be printed
* on the token in decimal. Maybe they will print larger S/N
* also in decimal but we can't be sure, thus do it only for
* these 32 bit numbers. */
unsigned long sn;
sn = app->serialno[4] * 16777216;
sn += app->serialno[5] * 65536;
sn += app->serialno[6] * 256;
sn += app->serialno[7];
result = xtryasprintf ("yk-%lu", sn);
}
else if (failmode)
result = NULL; /* No Abbreviated S/N. */
else
result = app_get_serialno (app);
return result;
}
/* Implementation of the GETATTR command. This is similar to the
* LEARN command but returns only one value via status lines. */
static gpg_error_t
do_getattr (app_t app, ctrl_t ctrl, const char *name)
{
static struct {
const char *name;
int tag;
int special;
} table[] = {
{ "SERIALNO", 0x0000, -1 },
{ "$AUTHKEYID", 0x0000, -2 }, /* Default key for ssh. */
{ "$DISPSERIALNO",0x0000, -3 }
};
gpg_error_t err = 0;
int idx;
void *relptr;
unsigned char *value;
size_t valuelen;
for (idx=0; (idx < DIM (table)
&& ascii_strcasecmp (table[idx].name, name)); idx++)
;
if (!(idx < DIM (table)))
err = gpg_error (GPG_ERR_INV_NAME);
else if (table[idx].special == -1)
{
char *serial = app_get_serialno (app);
if (serial)
{
send_status_direct (ctrl, "SERIALNO", serial);
xfree (serial);
}
}
else if (table[idx].special == -2)
{
char const tmp[] = "PIV.9A"; /* Cert PIV Authenticate. */
send_status_info (ctrl, table[idx].name, tmp, strlen (tmp), NULL, 0);
}
else if (table[idx].special == -3)
{
char *tmp = get_dispserialno (app, 1);
if (tmp)
{
send_status_info (ctrl, table[idx].name,
tmp, strlen (tmp),
NULL, (size_t)0);
xfree (tmp);
}
else
err = gpg_error (GPG_ERR_INV_NAME); /* No Abbreviated S/N. */
}
else
{
relptr = get_one_do (app, table[idx].tag, &value, &valuelen, &err);
if (relptr)
{
send_status_info (ctrl, table[idx].name, value, valuelen, NULL, 0);
xfree (relptr);
}
}
return err;
}
/* Send the KEYPAIRINFO back. DOBJ describes the data object carrying
* the key. This is used by the LEARN command. */
static gpg_error_t
send_keypair_and_cert_info (app_t app, ctrl_t ctrl, data_object_t dobj,
int only_keypair)
{
gpg_error_t err = 0;
char *keygripstr = NULL;
char idbuf[50];
err = get_keygrip_by_tag (app, dobj->tag, &keygripstr);
if (err)
goto leave;
snprintf (idbuf, sizeof idbuf, "PIV.%s", dobj->keyref);
send_status_info (ctrl, "KEYPAIRINFO",
keygripstr, strlen (keygripstr),
idbuf, strlen (idbuf),
NULL, (size_t)0);
if (!only_keypair)
{
/* All certificates are of type 100 (Regular X.509 Cert). */
send_status_info (ctrl, "CERTINFO",
"100", 3,
idbuf, strlen (idbuf),
NULL, (size_t)0);
}
leave:
xfree (keygripstr);
return err;
}
/* Handle the LEARN command for OpenPGP. */
static gpg_error_t
do_learn_status (app_t app, ctrl_t ctrl, unsigned int flags)
{
int i;
(void)flags;
for (i=0; data_objects[i].tag; i++)
if (data_objects[i].keypair)
send_keypair_and_cert_info (app, ctrl, data_objects + i, !!(flags & 1));
return 0;
}
/* Core of do-readcert which fetches the certificate based on the
* given tag and returns it in a freshly allocated buffer stored at
* R_CERT and the length of the certificate stored at R_CERTLEN. */
static gpg_error_t
readcert_by_tag (app_t app, unsigned int tag,
unsigned char **r_cert, size_t *r_certlen)
{
gpg_error_t err;
unsigned char *buffer;
size_t buflen;
void *relptr;
const unsigned char *s;
size_t n;
*r_cert = NULL;
*r_certlen = 0;
relptr = get_one_do (app, tag, &buffer, &buflen, NULL);
if (!relptr || !buflen)
{
err = gpg_error (GPG_ERR_NOT_FOUND);
goto leave;
}
s = find_tlv (buffer, buflen, 0x71, &n);
if (!s || n != 1)
{
log_error ("piv: no or invalid CertInfo in 0x%X\n", tag);
err = gpg_error (GPG_ERR_INV_CERT_OBJ);
goto leave;
}
if (*s == 0x01)
{
log_error ("piv: gzip compression not yet supported (tag 0x%X)\n", tag);
err = gpg_error (GPG_ERR_UNSUPPORTED_ENCODING);
goto leave;
}
if (*s)
{
log_error ("piv: invalid CertInfo 0x%02x in 0x%X\n", *s, tag);
err = gpg_error (GPG_ERR_INV_CERT_OBJ);
goto leave;
}
/* Note: We don't check that the LRC octet has a length of zero as
* required by the specs. */
/* Get the cert from the container. */
s = find_tlv (buffer, buflen, 0x70, &n);
if (!s || !n)
{
err = gpg_error (GPG_ERR_NOT_FOUND);
goto leave;
}
if (!(*r_cert = xtrymalloc (n)))
{
err = gpg_error_from_syserror ();
goto leave;
}
memcpy (*r_cert, s, n);
*r_certlen = n;
err = 0;
leave:
xfree (relptr);
return err;
}
/* Get the keygrip of a key from the certificate stored at TAG.
* Caller must free the string at R_KEYGRIPSTR. */
static gpg_error_t
get_keygrip_by_tag (app_t app, unsigned int tag, char **r_keygripstr)
{
gpg_error_t err;
unsigned char *certbuf = NULL;
size_t certbuflen;
ksba_cert_t cert = NULL;
*r_keygripstr = xtrymalloc (40+1);
if (!r_keygripstr)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* We need to get the public key from the certificate. */
err = readcert_by_tag (app, tag, &certbuf, &certbuflen);
if (err)
goto leave;
/* Compute the keygrip. */
err = ksba_cert_new (&cert);
if (err)
goto leave;
err = ksba_cert_init_from_mem (cert, certbuf, certbuflen);
if (err)
goto leave;
err = app_help_get_keygrip_string (cert, *r_keygripstr);
leave:
ksba_cert_release (cert);
xfree (certbuf);
if (err)
{
xfree (*r_keygripstr);
*r_keygripstr = NULL;
}
return err;
}
/* Locate the data object from the given KEYREF. The KEYREF may also
* be the corresponding OID of the key object. Returns the data
* object or NULL if not found. */
static data_object_t
find_dobj_by_keyref (app_t app, const char *keyref)
{
int i;
(void)app;
if (!ascii_strncasecmp (keyref, "PIV.", 4))
{
keyref += 4;
for (i=0; data_objects[i].tag; i++)
if (*data_objects[i].keyref
&& !ascii_strcasecmp (keyref, data_objects[i].keyref))
{
return data_objects + i;
}
}
else if (!strncmp (keyref, "2.16.840.1.101.3.7.", 19))
{
keyref += 19;
for (i=0; data_objects[i].tag; i++)
if (*data_objects[i].keyref
&& !strcmp (keyref, data_objects[i].oidsuffix))
{
return data_objects + i;
}
}
return NULL;
}
/* Read a certificate from the card and returned in a freshly
* allocated buffer stored at R_CERT and the length of the certificate
* stored at R_CERTLEN. CERTID is either the OID of the cert's
* container or of the form "PIV.<two_hexdigit_keyref>" */
static gpg_error_t
do_readcert (app_t app, const char *certid,
unsigned char **r_cert, size_t *r_certlen)
{
data_object_t dobj;
*r_cert = NULL;
*r_certlen = 0;
dobj = find_dobj_by_keyref (app, certid);
if (!dobj)
return gpg_error (GPG_ERR_INV_ID);
return readcert_by_tag (app, dobj->tag, r_cert, r_certlen);
}
/* Given a data object DOBJ return the corresponding PIV algorithm and
* store it at R_ALGO. The algorithm is taken from the corresponding
* certificate or from a cache. */
static gpg_error_t
get_key_algorithm_by_dobj (app_t app, data_object_t dobj, int *r_algo)
{
gpg_error_t err;
unsigned char *certbuf = NULL;
size_t certbuflen;
ksba_cert_t cert = NULL;
ksba_sexp_t k_pkey = NULL;
gcry_sexp_t s_pkey = NULL;
gcry_sexp_t l1 = NULL;
char *algoname = NULL;
int algo;
size_t n;
const char *curve_name;
*r_algo = 0;
err = readcert_by_tag (app, dobj->tag, &certbuf, &certbuflen);
if (err)
goto leave;
err = ksba_cert_new (&cert);
if (err)
goto leave;
err = ksba_cert_init_from_mem (cert, certbuf, certbuflen);
if (err)
{
log_error ("piv: failed to parse the certificate %s: %s\n",
dobj->keyref, gpg_strerror (err));
goto leave;
}
xfree (certbuf);
certbuf = NULL;
k_pkey = ksba_cert_get_public_key (cert);
if (!k_pkey)
{
err = gpg_error (GPG_ERR_NO_PUBKEY);
goto leave;
}
n = gcry_sexp_canon_len (k_pkey, 0, NULL, NULL);
err = gcry_sexp_new (&s_pkey, k_pkey, n, 0);
if (err)
goto leave;
l1 = gcry_sexp_find_token (s_pkey, "public-key", 0);
if (!l1)
{
err = gpg_error (GPG_ERR_NO_PUBKEY);
goto leave;
}
{
gcry_sexp_t l_tmp = gcry_sexp_cadr (l1);
gcry_sexp_release (l1);
l1 = l_tmp;
}
algoname = gcry_sexp_nth_string (l1, 0);
if (!algoname)
{
err = gpg_error_from_syserror ();
goto leave;
}
algo = gcry_pk_map_name (algoname);
switch (algo)
{
case GCRY_PK_RSA:
algo = PIV_ALGORITHM_RSA;
break;
case GCRY_PK_ECC:
case GCRY_PK_ECDSA:
case GCRY_PK_ECDH:
curve_name = gcry_pk_get_curve (s_pkey, 0, NULL);
if (curve_name && !strcmp (curve_name, "NIST P-256"))
algo = PIV_ALGORITHM_ECC_P256;
else if (curve_name && !strcmp (curve_name, "NIST P-384"))
algo = PIV_ALGORITHM_ECC_P384;
else
{
err = gpg_error (GPG_ERR_UNKNOWN_CURVE);
log_error ("piv: certificate %s, curve '%s': %s\n",
dobj->keyref, curve_name, gpg_strerror (err));
goto leave;
}
break;
default:
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
log_error ("piv: certificate %s, pubkey algo '%s': %s\n",
dobj->keyref, algoname, gpg_strerror (err));
goto leave;
}
*r_algo = algo;
leave:
gcry_free (algoname);
gcry_sexp_release (l1);
gcry_sexp_release (s_pkey);
ksba_free (k_pkey);
xfree (certbuf);
return err;
}
/* Return an allocated string to be used as prompt. Returns NULL on
* malloc error. */
static char *
make_prompt (app_t app, int remaining, const char *firstline)
{
char *serial, *tmpbuf, *result;
serial = get_dispserialno (app, 0);
if (!serial)
return NULL;
/* TRANSLATORS: Put a \x1f right before a colon. This can be
* used by pinentry to nicely align the names and values. Keep
* the %s at the start and end of the string. */
result = xtryasprintf (_("%s"
"Number\x1f: %s%%0A"
"Holder\x1f: %s"
"%s"),
"\x1e",
serial,
"Unknown", /* Fixme */
"");
xfree (serial);
/* Append a "remaining attempts" info if needed. */
if (remaining != -1 && remaining < 3)
{
char *rembuf;
/* TRANSLATORS: This is the number of remaining attempts to
* enter a PIN. Use %%0A (double-percent,0A) for a linefeed. */
rembuf = xtryasprintf (_("Remaining attempts: %d"), remaining);
if (rembuf)
{
tmpbuf = strconcat (firstline, "%0A%0A", result,
"%0A%0A", rembuf, NULL);
xfree (rembuf);
}
else
tmpbuf = NULL;
xfree (result);
result = tmpbuf;
}
else
{
tmpbuf = strconcat (firstline, "%0A%0A", result, NULL);
xfree (result);
result = tmpbuf;
}
return result;
}
/* Verify the Application PIN for use with data object DOBJ. */
static gpg_error_t
verify_pin (app_t app, data_object_t dobj,
gpg_error_t (*pincb)(void*,const char *,char **), void *pincb_arg)
{
gpg_error_t err;
unsigned char apdu[4];
unsigned int sw;
int remaining;
char *prompt;
char *pinvalue = NULL;
unsigned int pinlen;
char pinbuffer[8];
/* First check whether a verify is at all needed. This is done with
* P1 being 0 and no Lc and command data send. */
apdu[0] = 0x00;
apdu[1] = ISO7816_VERIFY;
apdu[2] = 0x00;
apdu[3] = 0x80;
if (!iso7816_apdu_direct (app->slot, apdu, 4, 0, &sw, NULL, NULL))
{
/* No need to verification. */
return 0; /* All fine. */
}
if ((sw & 0xfff0) == 0x63C0)
remaining = (sw & 0x000f); /* PIN has REMAINING tries left. */
else
remaining = -1;
if (remaining != -1)
log_debug ("piv: PIN for %s has %d attempts left\n",
dobj->keyref, remaining);
/* Ask for the PIN. */
prompt = make_prompt (app, remaining, _("||Please enter your PIV PIN"));
err = pincb (pincb_arg, prompt, &pinvalue);
xfree (prompt);
prompt = NULL;
if (err)
{
log_info (_("PIN callback returned error: %s\n"), gpg_strerror (err));
return err;
}
pinlen = pinvalue? strlen (pinvalue) : 0;
if (pinlen < 6)
{
log_error (_("PIN for is too short;"
" minimum length is %d\n"), 6);
if (pinvalue)
wipememory (pinvalue, pinlen);
xfree (pinvalue);
return gpg_error (GPG_ERR_BAD_PIN);
}
if (pinlen > sizeof pinbuffer)
{
log_error (_("PIN for is too long;"
" maximum length is %d\n"), (int)sizeof pinbuffer);
wipememory (pinvalue, pinlen);
xfree (pinvalue);
return gpg_error (GPG_ERR_BAD_PIN);
}
if (strspn (pinvalue, "0123456789") != pinlen)
{
log_error (_("PIN has invalid characters; only digits are allowed\n"));
wipememory (pinvalue, pinlen);
xfree (pinvalue);
return gpg_error (GPG_ERR_BAD_PIN);
}
memcpy (pinbuffer, pinvalue, pinlen);
memset (pinbuffer + pinlen, 0xff, sizeof(pinbuffer) - pinlen);
wipememory (pinvalue, pinlen);
xfree (pinvalue);
err = iso7816_verify (app->slot, 0x80,
pinbuffer, sizeof pinbuffer);
wipememory (pinbuffer, sizeof pinbuffer);
if (err)
log_error ("PIN verification failed: %s\n", gpg_strerror (err));
return err;
}
/* Compute a digital signature using the GENERAL AUTHENTICATE command
* on INDATA which is expected to be the raw message digest. The
* KEYIDSTR has the key reference or its OID (e.g. "PIV.9A"). The
* result is stored at (R_OUTDATA,R_OUTDATALEN); on error (NULL,0) is
* stored there and an error code returned. For ECDSA the result is
* the simple concatenation of R and S without any DER encoding. R
* and S are left extended with zeroes to make sure they have an equal
* length.
*/
static gpg_error_t
do_auth (app_t app, const char *keyidstr,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg,
const void *indata_arg, size_t indatalen,
unsigned char **r_outdata, size_t *r_outdatalen)
{
const unsigned char *indata = indata_arg;
gpg_error_t err;
data_object_t dobj;
unsigned char tmpl[2+2+2+128];
size_t tmpllen;
unsigned char *outdata = NULL;
size_t outdatalen;
const unsigned char *s;
size_t n;
int keyref, algo;
if (!keyidstr || !*keyidstr)
{
err = gpg_error (GPG_ERR_INV_VALUE);
goto leave;
}
/* Fixme: Shall we support the KEYID/FINGERPRINT syntax? Does it
* make sense for X.509 certs? */
dobj = find_dobj_by_keyref (app, keyidstr);
if (!dobj)
{
err = gpg_error (GPG_ERR_INV_ID);
goto leave;
}
keyref = xtoi_2 (dobj->keyref);
err = get_key_algorithm_by_dobj (app, dobj, &algo);
if (err)
goto leave;
/* We need to remove the ASN.1 prefix from INDATA. We use TEMPL as
* a temporary buffer for the OID. */
if (algo == PIV_ALGORITHM_ECC_P256)
{
tmpllen = sizeof tmpl;
err = gcry_md_get_asnoid (GCRY_MD_SHA256, &tmpl, &tmpllen);
if (err)
{
err = gpg_error (GPG_ERR_INTERNAL);
log_debug ("piv: no OID for hash algo %d\n", GCRY_MD_SHA256);
goto leave;
}
if (indatalen != tmpllen + 32 || memcmp (indata, tmpl, tmpllen))
{
err = GPG_ERR_INV_VALUE;
log_error ("piv: bad formatted input for ECC-P256 auth\n");
goto leave;
}
indata +=tmpllen;
indatalen -= tmpllen;
}
else if (algo == PIV_ALGORITHM_ECC_P384)
{
tmpllen = sizeof tmpl;
err = gcry_md_get_asnoid (GCRY_MD_SHA384, &tmpl, &tmpllen);
if (err)
{
err = gpg_error (GPG_ERR_INTERNAL);
log_debug ("piv: no OID for hash algo %d\n", GCRY_MD_SHA384);
goto leave;
}
if (indatalen != tmpllen + 48 || memcmp (indata, tmpl, tmpllen))
{
err = GPG_ERR_INV_VALUE;
log_error ("piv: bad formatted input for ECC-P384 auth\n");
goto leave;
}
indata += tmpllen;
indatalen -= tmpllen;
}
else if (algo == PIV_ALGORITHM_RSA)
{
err = gpg_error (GPG_ERR_NOT_IMPLEMENTED);
log_error ("piv: FIXME: implement RSA authentication\n");
goto leave;
}
else
{
err = gpg_error (GPG_ERR_INTERNAL);
log_debug ("piv: unknown PIV algo %d from helper function\n", algo);
goto leave;
}
/* Because we don't have a dynamic template builder we make sure
* that we can encode all lengths in one octet. FIXME: Use add_tls
* from app-openpgp as a base for an strconcat like function. */
if (indatalen >= 100)
{
err = gpg_error (GPG_ERR_TOO_LARGE);
goto leave;
}
/* Now verify the PIN. */
err = verify_pin (app, dobj, pincb, pincb_arg);
if (err)
return err;
/* Build the Dynamic Authentication Template. */
tmpl[0] = 0x7c;
tmpl[1] = indatalen + 4;
tmpl[2] = 0x82; /* Response. */
tmpl[3] = 0; /* Must be 0 to get the tag in the answer. */
tmpl[4] = 0x81; /* Challenge. */
tmpl[5] = indatalen;
memcpy (tmpl+6, indata, indatalen);
tmpllen = indatalen + 6;
/* Note: the -1 requests command chaining. */
err = iso7816_general_authenticate (app->slot, -1,
algo, keyref,
tmpl, (int)tmpllen, 0,
&outdata, &outdatalen);
if (err)
goto leave;
/* Parse the response. */
if (outdatalen && *outdata == 0x7c
&& (s = find_tlv (outdata, outdatalen, 0x82, &n)))
{
const unsigned char *rval, *sval;
size_t rlen, rlenx, slen, slenx, resultlen;
char *result;
/* The result of an ECDSA signature is
* SEQUENCE { r INTEGER, s INTEGER }
* We re-pack that by concatenating R and S and making sure that
* both have the same length. We simplify parsing by using
* find_tlv and not a proper DER parser. */
s = find_tlv (s, n, 0x30, &n);
if (!s)
goto bad_der;
rval = find_tlv (s, n, 0x02, &rlen);
if (!rval)
goto bad_der;
log_assert (n >= (rval-s)+rlen);
sval = find_tlv (rval+rlen, n-((rval-s)+rlen), 0x02, &slen);
if (!rval)
goto bad_der;
rlenx = slenx = 0;
if (rlen > slen)
slenx = rlen - slen;
else if (slen > rlen)
rlenx = slen - rlen;
resultlen = rlen + rlenx + slen + slenx;
result = xtrycalloc (1, resultlen);
if (!result)
{
err = gpg_error_from_syserror ();
goto leave;
}
memcpy (result + rlenx, rval, rlen);
memcpy (result + rlenx + rlen + slenx, sval, slen);
xfree (outdata);
outdata = result;
outdatalen = resultlen;
}
else
{
bad_der:
err = gpg_error (GPG_ERR_CARD);
log_error ("piv: response does not contain a proper result\n");
goto leave;
}
leave:
if (err)
{
xfree (outdata);
*r_outdata = NULL;
*r_outdatalen = 0;
}
else
{
*r_outdata = outdata;
*r_outdatalen = outdatalen;
}
return err;
}
/* Select the PIV application on the card in SLOT. This function must
* be used before any other PIV application functions. */
gpg_error_t
app_select_piv (app_t app)
{
static char const aid[] = { 0xA0, 0x00, 0x00, 0x03, 0x08, /* RID=NIST */
0x00, 0x00, 0x10, 0x00 /* PIX=PIV */ };
int slot = app->slot;
gpg_error_t err;
unsigned char *apt = NULL;
size_t aptlen;
const unsigned char *s;
size_t n;
/* Note that we select using the AID without the 2 octet version
* number. This allows for better reporting of future specs. We
* need to use the use-zero-for-P2-flag. */
err = iso7816_select_application_ext (slot, aid, sizeof aid, 0x0001,
&apt, &aptlen);
if (err)
goto leave;
app->apptype = "PIV";
app->did_chv1 = 0;
app->did_chv2 = 0;
app->did_chv3 = 0;
app->app_local = NULL;
/* Check the Application Property Template. */
if (opt.verbose)
{
/* We use a separate log_info to avoid the "DBG:" prefix. */
log_info ("piv: APT=");
log_printhex (apt, aptlen, "");
}
s = find_tlv (apt, aptlen, 0x4F, &n);
if (!s || n != 6 || memcmp (s, aid+5, 4))
{
/* The PIX does not match. */
log_error ("piv: missing or invalid DO 0x4F in APT\n");
err = gpg_error (GPG_ERR_CARD);
goto leave;
}
if (s[4] != 1 || s[5] != 0)
{
log_error ("piv: unknown PIV version %u.%u\n", s[4], s[5]);
err = gpg_error (GPG_ERR_CARD);
goto leave;
}
app->card_version = ((s[4] << 8) | s[5]);
s = find_tlv (apt, aptlen, 0x79, &n);
if (!s || n < 7)
{
log_error ("piv: missing or invalid DO 0x79 in APT\n");
err = gpg_error (GPG_ERR_CARD);
goto leave;
}
s = find_tlv (s, n, 0x4F, &n);
if (!s || n != 5 || memcmp (s, aid, 5))
{
/* The RID does not match. */
log_error ("piv: missing or invalid DO 0x79.4F in APT\n");
err = gpg_error (GPG_ERR_CARD);
goto leave;
}
app->app_local = xtrycalloc (1, sizeof *app->app_local);
if (!app->app_local)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* FIXME: Parse the optional and conditional DOs in the APT. */
if (opt.verbose)
dump_all_do (slot);
app->fnc.deinit = do_deinit;
app->fnc.learn_status = do_learn_status;
app->fnc.readcert = do_readcert;
app->fnc.readkey = NULL;
app->fnc.getattr = do_getattr;
/* app->fnc.setattr = do_setattr; */
/* app->fnc.writecert = do_writecert; */
/* app->fnc.writekey = do_writekey; */
/* app->fnc.genkey = do_genkey; */
/* app->fnc.sign = do_sign; */
app->fnc.auth = do_auth;
/* app->fnc.decipher = do_decipher; */
/* app->fnc.change_pin = do_change_pin; */
/* app->fnc.check_pin = do_check_pin; */
leave:
xfree (apt);
if (err)
do_deinit (app);
return err;
}
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