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gnupg/scd/app-piv.c

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/* app-piv.c - The OpenPGP card application.
* Copyright (C) 2019, 2020 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
* - https://developers.yubico.com/PIV/Introduction/PIV_attestation.html
*
* - Access control matrix:
* | Action | 9B | PIN | PUK | |
* |--------------+-----+-----+-----+------------------------------|
* | Generate key | yes | | | |
* | Change 9B | yes | | | |
* | Change retry | yes | yes | | Yubikey only |
* | Import key | yes | | | |
* | Import cert | yes | | | |
* | Change CHUID | yes | | | |
* | Reset card | | | | PIN and PUK in blocked state |
* | Verify PIN | | yes | | |
* | Sign data | | yes | | |
* | Decrypt data | | yes | | |
* | Change PIN | | yes | | |
* | Change PUK | | | yes | |
* | Unblock PIN | | | yes | New PIN required |
* |---------------------------------------------------------------|
* (9B indicates the 24 byte PIV Card Application Administration Key)
*
* - When generating a key we store the created public key in the
* corresponding data object, so that gpg and gpgsm are able to get
* the public key, create a certificate and store that then in that
* data object. That is not standard compliant but due to the use
* of other tags, it should not harm. See do_genkey for the actual
* used tag structure.
*/
#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 "../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
/* The AID for PIV. */
static char const piv_aid[] = { 0xA0, 0x00, 0x00, 0x03, 0x08, /* RID=NIST */
0x00, 0x00, 0x10, 0x00 /* PIX=PIV */ };
/* 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 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. */
const char keyref[3]; /* The key reference. */
const char *oidsuffix; /* Suffix of the OID. */
const char *usage; /* Usage string for a keypair or NULL. */
const 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, 0,0, 0, "", "1.219.0", NULL,
"Card Capability Container"},
{ 0x5FC102, 1, 0,0, 0,0, 0, "", "2.48.0", NULL,
"Cardholder Unique Id" },
{ 0x5FC105, 1, 0,1, 0,0, 1, "9A", "2.1.1", "a",
"Cert PIV Authentication" },
{ 0x5FC103, 1, 2,2, 0,0, 0, "", "2.96.16", NULL,
"Cardholder Fingerprints" },
{ 0x5FC106, 1, 0,1, 0,0, 0, "", "2.144.0", NULL,
"Security Object" },
{ 0x5FC108, 1, 2,2, 0,0, 0, "", "2.96.48", NULL,
"Cardholder Facial Image" },
{ 0x5FC101, 1, 0,0, 0,0, 1, "9E", "2.5.0", "a",
"Cert Card Authentication"},
{ 0x5FC10A, 0, 0,1, 0,0, 1, "9C", "2.1.0", "sc",
"Cert Digital Signature" },
{ 0x5FC10B, 0, 0,1, 0,0, 1, "9D", "2.1.2", "e",
"Cert Key Management" },
{ 0x5FC109, 0, 3,3, 0,0, 0, "", "2.48.1", NULL,
"Printed Information" },
{ 0x7E, 0, 0,0, 0,0, 0, "", "2.96.80", NULL,
"Discovery Object" },
{ 0x5FC10C, 0, 0,1, 0,0, 0, "", "2.96.96", NULL,
"Key History Object" },
{ 0x5FC10D, 0, 0,1, 0,0, 0, "82", "2.16.1", "e",
"Retired Cert Key Mgm 1" },
{ 0x5FC10E, 0, 0,1, 0,0, 0, "83", "2.16.2", "e",
"Retired Cert Key Mgm 2" },
{ 0x5FC10F, 0, 0,1, 0,0, 0, "84", "2.16.3", "e",
"Retired Cert Key Mgm 3" },
{ 0x5FC110, 0, 0,1, 0,0, 0, "85", "2.16.4", "e",
"Retired Cert Key Mgm 4" },
{ 0x5FC111, 0, 0,1, 0,0, 0, "86", "2.16.5", "e",
"Retired Cert Key Mgm 5" },
{ 0x5FC112, 0, 0,1, 0,0, 0, "87", "2.16.6", "e",
"Retired Cert Key Mgm 6" },
{ 0x5FC113, 0, 0,1, 0,0, 0, "88", "2.16.7", "e",
"Retired Cert Key Mgm 7" },
{ 0x5FC114, 0, 0,1, 0,0, 0, "89", "2.16.8", "e",
"Retired Cert Key Mgm 8" },
{ 0x5FC115, 0, 0,1, 0,0, 0, "8A", "2.16.9", "e",
"Retired Cert Key Mgm 9" },
{ 0x5FC116, 0, 0,1, 0,0, 0, "8B", "2.16.10", "e",
"Retired Cert Key Mgm 10" },
{ 0x5FC117, 0, 0,1, 0,0, 0, "8C", "2.16.11", "e",
"Retired Cert Key Mgm 11" },
{ 0x5FC118, 0, 0,1, 0,0, 0, "8D", "2.16.12", "e",
"Retired Cert Key Mgm 12" },
{ 0x5FC119, 0, 0,1, 0,0, 0, "8E", "2.16.13", "e",
"Retired Cert Key Mgm 13" },
{ 0x5FC11A, 0, 0,1, 0,0, 0, "8F", "2.16.14", "e",
"Retired Cert Key Mgm 14" },
{ 0x5FC11B, 0, 0,1, 0,0, 0, "90", "2.16.15", "e",
"Retired Cert Key Mgm 15" },
{ 0x5FC11C, 0, 0,1, 0,0, 0, "91", "2.16.16", "e",
"Retired Cert Key Mgm 16" },
{ 0x5FC11D, 0, 0,1, 0,0, 0, "92", "2.16.17", "e",
"Retired Cert Key Mgm 17" },
{ 0x5FC11E, 0, 0,1, 0,0, 0, "93", "2.16.18", "e",
"Retired Cert Key Mgm 18" },
{ 0x5FC11F, 0, 0,1, 0,0, 0, "94", "2.16.19", "e",
"Retired Cert Key Mgm 19" },
{ 0x5FC120, 0, 0,1, 0,0, 0, "95", "2.16.20", "e",
"Retired Cert Key Mgm 20" },
{ 0x5FC121, 0, 2,2, 0,0, 0, "", "2.16.21", NULL,
"Cardholder Iris Images" },
{ 0x7F61, 0, 0,0, 0,0, 0, "", "2.16.22", NULL,
"BIT Group Template" },
{ 0x5FC122, 0, 0,0, 0,0, 0, "", "2.16.23", NULL,
"SM Cert Signer" },
{ 0x5FC123, 0, 3,3, 0,0, 0, "", "2.16.24", NULL,
"Pairing Code Ref Data" },
{ 0 }
/* Other key reference values without a data object:
* "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
*
* Yubikey specific data objects:
* "F9" Attestation key (preloaded can be replaced)
*/
};
/* 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 yubikey:1; /* This is on a Yubikey. */
} flags;
/* Keep track on whether we cache a certain PIN so that we get it
* from the cache only if we know we cached it. This inhibits the
* use of the same cache entry for a card plugged in and out without
* gpg-agent having noticed that due to a bug. */
struct
{
unsigned int maybe_00:1;
unsigned int maybe_80:1;
unsigned int maybe_81:1;
unsigned int maybe_96:1;
unsigned int maybe_97:1;
unsigned int maybe_98:1;
unsigned int maybe_9B:1;
} pincache;
};
/***** Local prototypes *****/
static gpg_error_t get_keygrip_by_tag (app_t app, unsigned int tag,
char **r_keygripstr, int *got_cert);
static gpg_error_t genkey_parse_rsa (const unsigned char *data, size_t datalen,
gcry_sexp_t *r_sexp);
static gpg_error_t genkey_parse_ecc (const unsigned char *data, size_t datalen,
int mechanism, gcry_sexp_t *r_sexp);
/* 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_get_slot (app), 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;
}
/* Remove data object described by TAG from the cache. If TAG is 0
* all cache iterms are flushed. */
static void
flush_cached_data (app_t app, int tag)
{
struct cache_s *c, *cprev;
for (c=app->app_local->cache, cprev=NULL; c; cprev=c, c = c->next)
if (c->tag == tag || !tag)
{
if (cprev)
cprev->next = c->next;
else
app->app_local->cache = c->next;
xfree (c);
for (c=app->app_local->cache; c ; c = c->next)
{
log_assert (c->tag != tag); /* Oops: duplicated entry. */
}
return;
}
}
/* 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].tag == 0x5FC109)
log_info ("DO '%s': '%.*s'\n", data_objects[i].desc,
(int)buflen, buffer);
else
{
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, "");
}
}
xfree (buffer); buffer = NULL;
}
}
/* Create a TLV tag and value and store it at BUFFER. Return the
* length of tag and length. A LENGTH greater than 65535 is
* truncated. TAG must be less or equal to 2^16. If BUFFER is NULL,
* only the required length is computed. */
static size_t
add_tlv (unsigned char *buffer, unsigned int tag, size_t length)
{
if (length > 0xffff)
length = 0xffff;
if (buffer)
{
unsigned char *p = buffer;
if (tag > 0xff)
*p++ = tag >> 8;
*p++ = tag;
if (length < 128)
*p++ = length;
else if (length < 256)
{
*p++ = 0x81;
*p++ = length;
}
else
{
*p++ = 0x82;
*p++ = length >> 8;
*p++ = length;
}
return p - buffer;
}
else
{
size_t n = 0;
if (tag > 0xff)
n++;
n++;
if (length < 128)
n++;
else if (length < 256)
n += 2;
else
n += 3;
return n;
}
}
/* Function to build a list of TLV and return the result in a mallcoed
* buffer. The varargs are tuples of (int,size_t,void) each with the
* tag, the length and the actual data. A (0,0,NULL) tuple terminates
* the list. Up to 10 tuples are supported. If SECMEM is true the
* returned buffer is allocated in secure memory. */
static gpg_error_t
concat_tlv_list (int secure, unsigned char **r_result, size_t *r_resultlen, ...)
{
gpg_error_t err;
va_list arg_ptr;
struct {
int tag;
unsigned int len;
unsigned int contlen;
const void *data;
} argv[10];
int i, j, argc;
unsigned char *data = NULL;
size_t datalen;
unsigned char *p;
size_t n;
*r_result = NULL;
*r_resultlen = 0;
/* Collect all args. Check that length is <= 2^16 to match the
* behaviour of add_tlv. */
va_start (arg_ptr, r_resultlen);
argc = 0;
while (((argv[argc].tag = va_arg (arg_ptr, int))))
{
argv[argc].len = va_arg (arg_ptr, size_t);
argv[argc].contlen = 0;
argv[argc].data = va_arg (arg_ptr, const void *);
if (argc >= DIM (argv)-1 || argv[argc].len > 0xffff)
{
va_end (arg_ptr);
err = gpg_error (GPG_ERR_EINVAL);
goto leave;
}
argc++;
}
va_end (arg_ptr);
/* Compute the required buffer length and allocate the buffer. */
datalen = 0;
for (i=0; i < argc; i++)
{
if (!argv[i].len && !argv[i].data)
{
/* Constructed tag. Compute its length. Note that we
* currently allow only one constructed tag in the list. */
for (n=0, j = i + 1; j < argc; j++)
{
log_assert (!(!argv[j].len && !argv[j].data));
n += add_tlv (NULL, argv[j].tag, argv[j].len);
n += argv[j].len;
}
argv[i].contlen = n;
datalen += add_tlv (NULL, argv[i].tag, n);
}
else
{
datalen += add_tlv (NULL, argv[i].tag, argv[i].len);
datalen += argv[i].len;
}
}
data = secure? xtrymalloc_secure (datalen) : xtrymalloc (datalen);
if (!data)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Copy that data to the buffer. */
p = data;
for (i=0; i < argc; i++)
{
if (!argv[i].len && !argv[i].data)
{
/* Constructed tag. */
p += add_tlv (p, argv[i].tag, argv[i].contlen);
}
else
{
p += add_tlv (p, argv[i].tag, argv[i].len);
memcpy (p, argv[i].data, argv[i].len);
p += argv[i].len;
}
}
log_assert ( data + datalen == p );
*r_result = data;
data = NULL;
*r_resultlen = datalen;
err = 0;
leave:
xfree (data);
return err;
}
/* Wrapper around iso7816_put_data_odd which also sets the tag into
* the '5C' data object. The varargs are tuples of (int,size_t,void)
* with the tag, the length and the actual data. A (0,0,NULL) tuple
* terminates the list. Up to 10 tuples are supported. */
static gpg_error_t
put_data (int slot, unsigned int tag, ...)
{
gpg_error_t err;
va_list arg_ptr;
struct {
int tag;
size_t len;
const void *data;
} argv[10];
int i, argc;
unsigned char data5c[5];
size_t data5clen;
unsigned char *data = NULL;
size_t datalen;
unsigned char *p;
size_t n;
/* Collect all args. Check that length is <= 2^16 to match the
* behaviour of add_tlv. */
va_start (arg_ptr, tag);
argc = 0;
while (((argv[argc].tag = va_arg (arg_ptr, int))))
{
argv[argc].len = va_arg (arg_ptr, size_t);
argv[argc].data = va_arg (arg_ptr, const void *);
if (argc >= DIM (argv)-1 || argv[argc].len > 0xffff)
{
va_end (arg_ptr);
return GPG_ERR_EINVAL;
}
argc++;
}
va_end (arg_ptr);
/* Build the TLV with the tag to be updated. */
data5c[0] = 0x5c; /* Tag list */
if (tag <= 0xff)
{
data5c[1] = 1;
data5c[2] = tag;
data5clen = 3;
}
else if (tag <= 0xffff)
{
data5c[1] = 2;
data5c[2] = (tag >> 8);
data5c[3] = tag;
data5clen = 4;
}
else
{
data5c[1] = 3;
data5c[2] = (tag >> 16);
data5c[3] = (tag >> 8);
data5c[4] = tag;
data5clen = 5;
}
/* Compute the required buffer length and allocate the buffer. */
n = 0;
for (i=0; i < argc; i++)
{
n += add_tlv (NULL, argv[i].tag, argv[i].len);
n += argv[i].len;
}
datalen = data5clen + add_tlv (NULL, 0x53, n) + n;
data = xtrymalloc (datalen);
if (!data)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Copy that data to the buffer. */
p = data;
memcpy (p, data5c, data5clen);
p += data5clen;
p += add_tlv (p, 0x53, n);
for (i=0; i < argc; i++)
{
p += add_tlv (p, argv[i].tag, argv[i].len);
memcpy (p, argv[i].data, argv[i].len);
p += argv[i].len;
}
log_assert ( data + datalen == p );
err = iso7816_put_data_odd (slot, -1 /* use command chaining */,
0x3fff, data, datalen);
leave:
xfree (data);
return err;
}
/* Parse the key reference KEYREFSTR which is expected to hold a key
* reference for a CHV object. Return the one octet keyref or -1 for
* an invalid reference. */
static int
parse_chv_keyref (const char *keyrefstr)
{
if (!keyrefstr)
return -1;
else if (!ascii_strcasecmp (keyrefstr, "PIV.00"))
return 0x00;
else if (!ascii_strcasecmp (keyrefstr, "PIV.80"))
return 0x80;
else if (!ascii_strcasecmp (keyrefstr, "PIV.81"))
return 0x81;
else
return -1;
}
/* 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->card && app->card->serialno && app->card->serialnolen == 3+1+4
&& !memcmp (app->card->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->card->serialno[4] * 16777216;
sn += app->card->serialno[5] * 65536;
sn += app->card->serialno[6] * 256;
sn += app->card->serialno[7];
result = xtryasprintf ("yk-%lu", sn);
}
else if (failmode)
result = NULL; /* No Abbreviated S/N. */
else
result = app_get_serialno (app);
return result;
}
/* The verify command can be used to retrieve the security status of
* the card. Given the PIN name (e.g. "PIV.80" for the application
* pin, a status is returned:
*
* -1 = Error retrieving the data,
* -2 = No such PIN,
* -3 = PIN blocked,
* -5 = Verified and still valid,
* n >= 0 = Number of verification attempts left.
*/
static int
get_chv_status (app_t app, const char *keyrefstr)
{
unsigned char apdu[4];
unsigned int sw;
int result;
int keyref;
keyref = parse_chv_keyref (keyrefstr);
if (!keyrefstr)
return -1;
apdu[0] = 0x00;
apdu[1] = ISO7816_VERIFY;
apdu[2] = 0x00;
apdu[3] = keyref;
if (!iso7816_apdu_direct (app_get_slot (app), apdu, 4, 0, &sw, NULL, NULL))
result = -5; /* No need to verification. */
else if (sw == 0x6a88 || sw == 0x6a80)
result = -2; /* No such PIN. */
else if (sw == 0x6983)
result = -3; /* PIN is blocked. */
else if ((sw & 0xfff0) == 0x63C0)
result = (sw & 0x000f);
else
result = -1; /* Error. */
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 },
{ "$AUTHKEYID", 0x0000, -2 }, /* Default ssh key. */
{ "$ENCRKEYID", 0x0000, -6 }, /* Default encryption key. */
{ "$SIGNKEYID", 0x0000, -7 }, /* Default signing key. */
{ "$DISPSERIALNO",0x0000, -3 },
{ "CHV-STATUS", 0x0000, -4 },
{ "CHV-USAGE", 0x007E, -5 }
};
gpg_error_t err = 0;
int idx;
void *relptr;
unsigned char *value;
size_t valuelen;
const unsigned char *s;
size_t n;
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 if (table[idx].special == -4) /* CHV-STATUS */
{
int tmp[4];
tmp[0] = get_chv_status (app, "PIV.00");
tmp[1] = get_chv_status (app, "PIV.80");
tmp[2] = get_chv_status (app, "PIV.81");
err = send_status_printf (ctrl, table[idx].name, "%d %d %d",
tmp[0], tmp[1], tmp[2]);
}
else if (table[idx].special == -5) /* CHV-USAGE (aka PIN Usage Policy) */
{
/* We return 2 hex bytes or nothing in case the discovery object
* is not supported. */
relptr = get_one_do (app, table[idx].tag, &value, &valuelen, &err);
if (relptr)
{
s = find_tlv (value, valuelen, 0x7E, &n);
if (s && n && (s = find_tlv (s, n, 0x5F2F, &n)) && n >=2 )
err = send_status_printf (ctrl, table[idx].name, "%02X %02X",
s[0], s[1]);
xfree (relptr);
}
}
else if (table[idx].special == -6)
{
char const tmp[] = "PIV.9D"; /* Key Management. */
send_status_info (ctrl, table[idx].name, tmp, strlen (tmp), NULL, 0);
}
else if (table[idx].special == -7)
{
char const tmp[] = "PIV.9C"; /* Digital Signature. */
send_status_info (ctrl, table[idx].name, tmp, strlen (tmp), NULL, 0);
}
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;
}
/* Authenticate the card using the Card Application Administration
* Key. (VALUE,VALUELEN) has that 24 byte key. */
static gpg_error_t
auth_adm_key (app_t app, const unsigned char *value, size_t valuelen)
{
gpg_error_t err;
unsigned char tmpl[4+24];
size_t tmpllen;
unsigned char *outdata = NULL;
size_t outdatalen;
const unsigned char *s;
char witness[8];
size_t n;
gcry_cipher_hd_t cipher = NULL;
/* Prepare decryption. */
err = gcry_cipher_open (&cipher, GCRY_CIPHER_3DES, GCRY_CIPHER_MODE_ECB, 0);
if (err)
goto leave;
err = gcry_cipher_setkey (cipher, value, valuelen);
if (err)
goto leave;
/* Request a witness. */
tmpl[0] = 0x7c;
tmpl[1] = 0x02;
tmpl[2] = 0x80;
tmpl[3] = 0; /* (Empty witness requests a witness.) */
tmpllen = 4;
err = iso7816_general_authenticate (app_get_slot (app), 0,
PIV_ALGORITHM_3DES_ECB_0, 0x9B,
tmpl, tmpllen, 0,
&outdata, &outdatalen);
if (gpg_err_code (err) == GPG_ERR_BAD_PIN)
err = gpg_error (GPG_ERR_BAD_AUTH);
if (err)
goto leave;
if (!(outdatalen && *outdata == 0x7c
&& (s = find_tlv (outdata, outdatalen, 0x80, &n))
&& n == 8))
{
err = gpg_error (GPG_ERR_CARD);
log_error ("piv: improper witness received\n");
goto leave;
}
err = gcry_cipher_decrypt (cipher, witness, 8, s, 8);
if (err)
goto leave;
/* Return decrypted witness and send our challenge. */
tmpl[0] = 0x7c;
tmpl[1] = 22;
tmpl[2] = 0x80;
tmpl[3] = 8;
memcpy (tmpl+4, witness, 8);
tmpl[12] = 0x81;
tmpl[13] = 8;
gcry_create_nonce (tmpl+14, 8);
tmpl[22] = 0x80;
tmpl[23] = 0;
tmpllen = 24;
xfree (outdata);
err = iso7816_general_authenticate (app_get_slot (app), 0,
PIV_ALGORITHM_3DES_ECB_0, 0x9B,
tmpl, tmpllen, 0,
&outdata, &outdatalen);
if (gpg_err_code (err) == GPG_ERR_BAD_PIN)
err = gpg_error (GPG_ERR_BAD_AUTH);
if (err)
goto leave;
if (!(outdatalen && *outdata == 0x7c
&& (s = find_tlv (outdata, outdatalen, 0x82, &n))
&& n == 8))
{
err = gpg_error (GPG_ERR_CARD);
log_error ("piv: improper challenge received\n");
goto leave;
}
/* (We reuse the witness buffer.) */
err = gcry_cipher_decrypt (cipher, witness, 8, s, 8);
if (err)
goto leave;
if (memcmp (witness, tmpl+14, 8))
{
err = gpg_error (GPG_ERR_BAD_AUTH);
goto leave;
}
leave:
xfree (outdata);
gcry_cipher_close (cipher);
return err;
}
/* Set a new admin key. */
static gpg_error_t
set_adm_key (app_t app, const unsigned char *value, size_t valuelen)
{
gpg_error_t err;
unsigned char apdu[8+24];
unsigned int sw;
/* Check whether it is a weak key and that it is of proper length. */
{
gcry_cipher_hd_t cipher;
err = gcry_cipher_open (&cipher, GCRY_CIPHER_3DES, GCRY_CIPHER_MODE_ECB, 0);
if (!err)
{
err = gcry_cipher_setkey (cipher, value, valuelen);
gcry_cipher_close (cipher);
}
if (err)
goto leave;
}
if (app->app_local->flags.yubikey)
{
/* This is a Yubikey. */
if (valuelen != 24)
{
err = gpg_error (GPG_ERR_INV_LENGTH);
goto leave;
}
/* We use a proprietary Yubikey command. */
apdu[0] = 0;
apdu[1] = 0xff;
apdu[2] = 0xff;
apdu[3] = 0xff; /* touch policy: 0xff=never, 0xfe = always. */
apdu[4] = 3 + 24;
apdu[5] = PIV_ALGORITHM_3DES_ECB;
apdu[6] = 0x9b;
apdu[7] = 24;
memcpy (apdu+8, value, 24);
err = iso7816_apdu_direct (app_get_slot (app), apdu, 8+24, 0,
&sw, NULL, NULL);
wipememory (apdu+8, 24);
if (err)
log_error ("piv: setting admin key failed; sw=%04x\n", sw);
/* A PIN is not required, thus use a better error code. */
if (gpg_err_code (err) == GPG_ERR_BAD_PIN)
err = gpg_error (GPG_ERR_NO_AUTH);
}
else
err = gpg_error (GPG_ERR_NOT_SUPPORTED);
leave:
return err;
}
/* Handle the SETATTR operation. All arguments are already basically
* checked. */
static gpg_error_t
do_setattr (app_t app, ctrl_t ctrl, const char *name,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg,
const unsigned char *value, size_t valuelen)
{
gpg_error_t err;
static struct {
const char *name;
unsigned short tag;
unsigned short flush_tag; /* The tag which needs to be flushed or 0. */
int special; /* Special mode to use for thus NAME. */
} table[] = {
/* Authenticate using the PIV Card Application Administration Key
* (0x0B). Note that Yubico calls this key the "management key"
* which we don't do because that term is too similar to "Cert
* Management Key" (0x9D). */
{ "AUTH-ADM-KEY", 0x0000, 0x0000, 1 },
{ "SET-ADM-KEY", 0x0000, 0x0000, 2 }
};
int idx;
(void)ctrl;
(void)pincb;
(void)pincb_arg;
for (idx=0; (idx < DIM (table)
&& ascii_strcasecmp (table[idx].name, name)); idx++)
;
if (!(idx < DIM (table)))
return gpg_error (GPG_ERR_INV_NAME);
/* Flush the cache before writing it, so that the next get operation
* will reread the data from the card and thus get synced in case of
* errors (e.g. data truncated by the card). */
if (table[idx].tag)
flush_cached_data (app, table[idx].flush_tag? table[idx].flush_tag
/* */ : table[idx].tag);
switch (table[idx].special)
{
case 1:
err = auth_adm_key (app, value, valuelen);
break;
case 2:
err = set_adm_key (app, value, valuelen);
break;
default:
err = gpg_error (GPG_ERR_BUG);
break;
}
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;
int got_cert;
char idbuf[50];
const char *usage;
err = get_keygrip_by_tag (app, dobj->tag, &keygripstr, &got_cert);
if (err)
goto leave;
usage = dobj->usage? dobj->usage : "";
snprintf (idbuf, sizeof idbuf, "PIV.%s", dobj->keyref);
send_status_info (ctrl, "KEYPAIRINFO",
keygripstr, strlen (keygripstr),
idbuf, strlen (idbuf),
usage, strlen (usage),
NULL, (size_t)0);
if (!only_keypair && got_cert)
{
/* 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. */
static gpg_error_t
do_learn_status (app_t app, ctrl_t ctrl, unsigned int flags)
{
int i;
(void)flags;
do_getattr (app, ctrl, "CHV-USAGE");
do_getattr (app, ctrl, "CHV-STATUS");
for (i=0; data_objects[i].tag; i++)
if (data_objects[i].keypair)
send_keypair_and_cert_info (app, ctrl, data_objects + i,
!!(flags & APP_LEARN_FLAG_KEYPAIRINFO));
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. If
* on success a non-zero value is stored at R_MECHANISM, the returned
* data is not a certificate but a public key (in the format used by the
* container '7f49'. */
static gpg_error_t
readcert_by_tag (app_t app, unsigned int tag,
unsigned char **r_cert, size_t *r_certlen, int *r_mechanism)
{
gpg_error_t err;
unsigned char *buffer;
size_t buflen;
void *relptr;
const unsigned char *s, *s2;
size_t n, n2;
*r_cert = NULL;
*r_certlen = 0;
*r_mechanism = 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)
{
/* No certificate; check whether a public key has been stored
* using our own scheme. */
s = find_tlv (buffer, buflen, 0x7f49, &n);
if (!s || !n)
{
log_error ("piv: No public key in 0x%X\n", tag);
err = gpg_error (GPG_ERR_NO_PUBKEY);
goto leave;
}
s2 = find_tlv (buffer, buflen, 0x80, &n2);
if (!s2 || n2 != 1 || !*s2)
{
log_error ("piv: No mechanism for public key in 0x%X\n", tag);
err = gpg_error (GPG_ERR_NO_PUBKEY);
goto leave;
}
*r_mechanism = *s2;
}
else
{
if (n != 1)
{
log_error ("piv: 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;
}
}
/* The next is common for certificate and public key. */
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 in hex format 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, int *r_got_cert)
{
gpg_error_t err;
unsigned char *certbuf = NULL;
size_t certbuflen;
int mechanism;
gcry_sexp_t s_pkey = NULL;
ksba_cert_t cert = NULL;
unsigned char grip[KEYGRIP_LEN];
*r_got_cert = 0;
*r_keygripstr = xtrymalloc (2*KEYGRIP_LEN+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, &mechanism);
if (err)
goto leave;
if (mechanism) /* Compute keygrip from public key. */
{
if (mechanism == PIV_ALGORITHM_RSA)
err = genkey_parse_rsa (certbuf, certbuflen, &s_pkey);
else if (mechanism == PIV_ALGORITHM_ECC_P256
|| mechanism == PIV_ALGORITHM_ECC_P384)
err = genkey_parse_ecc (certbuf, certbuflen, mechanism, &s_pkey);
else
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
if (err)
goto leave;
if (!gcry_pk_get_keygrip (s_pkey, grip))
{
log_error ("piv: error computing keygrip\n");
err = gpg_error (GPG_ERR_GENERAL);
goto leave;
}
bin2hex (grip, sizeof grip, *r_keygripstr);
}
else /* Compute keygrip from certificate. */
{
*r_got_cert = 0;
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:
gcry_sexp_release (s_pkey);
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)) /* Standard keyref */
{
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)) /* OID */
{
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;
}
}
else if (strlen (keyref) == 40) /* A keygrip */
{
char *keygripstr = NULL;
int tag, dummy_got_cert;
for (i=0; (tag=data_objects[i].tag); i++)
{
if (!data_objects[i].keypair)
continue;
xfree (keygripstr);
if (get_keygrip_by_tag (app, tag, &keygripstr, &dummy_got_cert))
continue;
if (!strcmp (keygripstr, keyref))
{
xfree (keygripstr);
return data_objects + i;
}
}
xfree (keygripstr);
}
return NULL;
}
/* Return the keyref from DOBJ as an integer. If it does not exist,
* return -1. */
static int
keyref_from_dobj (data_object_t dobj)
{
if (!dobj || !hexdigitp (dobj->keyref) || !hexdigitp (dobj->keyref+1))
return -1;
return xtoi_2 (dobj->keyref);
}
/* 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)
{
gpg_error_t err;
data_object_t dobj;
int mechanism;
*r_cert = NULL;
*r_certlen = 0;
/* Hack to read a Yubikey attestation certificate. */
if (app->app_local->flags.yubikey
&& strlen (certid) == 11
&& !ascii_strncasecmp (certid, "PIV.ATST.", 9)
&& hexdigitp (certid+9) && hexdigitp (certid+10))
{
unsigned char apdu[4];
unsigned char *result;
size_t resultlen;
apdu[0] = 0;
apdu[1] = 0xf9; /* Yubikey: Get attestation cert. */
apdu[2] = xtoi_2 (certid+9);
apdu[3] = 0;
err = iso7816_apdu_direct (app_get_slot (app), apdu, 4, 1,
NULL, &result, &resultlen);
if (!err)
{
*r_cert = result;
*r_certlen = resultlen;
}
return err;
}
dobj = find_dobj_by_keyref (app, certid);
if (!dobj)
return gpg_error (GPG_ERR_INV_ID);
err = readcert_by_tag (app, dobj->tag, r_cert, r_certlen, &mechanism);
if (!err && mechanism)
{
/* Well, no certificate but a public key - we don't want it. */
xfree (*r_cert);
*r_cert = NULL;
*r_certlen = 0;
err = gpg_error (GPG_ERR_NOT_FOUND);
}
return err;
}
/* Return a public key in a freshly allocated buffer. This will only
* work for a freshly generated key as long as no reset of the
* application has been performed. This is because we return a cached
* result from key generation. If no cached result is available, the
* error GPG_ERR_UNSUPPORTED_OPERATION is returned so that the higher
* layer can then get the key by reading the matching certificate.
* On success a canonical encoded s-expression with the public key is
* stored at (R_PK,R_PKLEN); the caller must release that buffer. On
* error R_PK and R_PKLEN are not changed and an error code is
* returned.
*/
static gpg_error_t
do_readkey (app_t app, ctrl_t ctrl, const char *keyrefstr, unsigned int flags,
unsigned char **r_pk, size_t *r_pklen)
{
gpg_error_t err;
data_object_t dobj;
int keyref;
unsigned char *cert = NULL;
size_t certlen;
int mechanism;
gcry_sexp_t s_pkey = NULL;
unsigned char *pk = NULL;
size_t pklen;
dobj = find_dobj_by_keyref (app, keyrefstr);
if ((keyref = keyref_from_dobj (dobj)) == -1)
{
err = gpg_error (GPG_ERR_INV_ID);
goto leave;
}
err = readcert_by_tag (app, dobj->tag, &cert, &certlen, &mechanism);
if (err)
goto leave;
if (!mechanism)
{
/* We got a certificate. Extract the pubkey from it. */
err = app_help_pubkey_from_cert (cert, certlen, &pk, &pklen);
if (err)
{
log_error ("failed to parse the certificate: %s\n",
gpg_strerror (err));
goto leave;
}
}
else
{
/* Convert the public key into the expected s-expression. */
if (mechanism == PIV_ALGORITHM_RSA)
err = genkey_parse_rsa (cert, certlen, &s_pkey);
else if (mechanism == PIV_ALGORITHM_ECC_P256
|| mechanism == PIV_ALGORITHM_ECC_P384)
err = genkey_parse_ecc (cert, certlen, mechanism, &s_pkey);
else
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
if (err)
goto leave;
err = make_canon_sexp (s_pkey, &pk, &pklen);
if (err)
goto leave;
}
if ((flags & APP_READKEY_FLAG_INFO))
{
char keygripstr[KEYGRIP_LEN*2+1];
char idbuf[50];
const char *usage;
err = app_help_get_keygrip_string_pk (pk, pklen, keygripstr);
if (err)
{
log_error ("app_help_get_keygrip_string_pk failed: %s\n",
gpg_strerror (err));
goto leave;
}
usage = dobj->usage? dobj->usage : "";
snprintf (idbuf, sizeof idbuf, "PIV.%s", dobj->keyref);
send_status_info (ctrl, "KEYPAIRINFO",
keygripstr, strlen (keygripstr),
idbuf, strlen (idbuf),
usage, strlen (usage),
NULL, (size_t)0);
}
if (r_pk && r_pklen)
{
*r_pk = pk;
pk = NULL;
*r_pklen = pklen;
}
leave:
gcry_sexp_release (s_pkey);
xfree (pk);
xfree (cert);
return err;
}
/* 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_mechanism)
{
gpg_error_t err;
unsigned char *certbuf = NULL;
size_t certbuflen;
int mechanism;
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_mechanism = 0;
err = readcert_by_tag (app, dobj->tag, &certbuf, &certbuflen, &mechanism);
if (err)
goto leave;
if (mechanism)
{
/* A public key was found. That makes it easy. */
switch (mechanism)
{
case PIV_ALGORITHM_RSA:
case PIV_ALGORITHM_ECC_P256:
case PIV_ALGORITHM_ECC_P384:
*r_mechanism = mechanism;
break;
default:
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
log_error ("piv: unknown mechanism %d in public key at %s\n",
mechanism, dobj->keyref);
break;
}
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_mechanism = algo;
leave:
gcry_free (algoname);
gcry_sexp_release (l1);
gcry_sexp_release (s_pkey);
ksba_free (k_pkey);
xfree (certbuf);
return err;
}
/* Helper to cache the pin PINNO. If PIN is NULL the cache is cleared. */
static void
cache_pin (app_t app, ctrl_t ctrl, int pinno,
const char *pin, unsigned int pinlen)
{
char pinref[20];
if (pinno < 0)
return;
switch (app->card->cardtype)
{
case CARDTYPE_YUBIKEY: break;
default: return;
}
snprintf (pinref, sizeof pinref, "%02x", pinno);
pincache_put (ctrl, app_get_slot (app), "piv", pinref, pin, pinlen);
switch (pinno)
{
case 0x00: app->app_local->pincache.maybe_00 = !!pin; break;
case 0x80: app->app_local->pincache.maybe_80 = !!pin; break;
case 0x81: app->app_local->pincache.maybe_81 = !!pin; break;
case 0x96: app->app_local->pincache.maybe_96 = !!pin; break;
case 0x97: app->app_local->pincache.maybe_97 = !!pin; break;
case 0x98: app->app_local->pincache.maybe_98 = !!pin; break;
case 0x9B: app->app_local->pincache.maybe_9B = !!pin; break;
}
}
/* If the PIN cache is available and really has a valid PIN return
* that pin at R_PIN. Returns true if that is the case; otherwise
* false. */
static int
pin_from_cache (app_t app, ctrl_t ctrl, int pinno, char **r_pin)
{
char pinref[20];
int maybe_cached;
*r_pin = NULL;
if (pinno < 0)
return 0;
switch (app->card->cardtype)
{
case CARDTYPE_YUBIKEY: break;
default: return 0;
}
switch (pinno)
{
case 0x00: maybe_cached = app->app_local->pincache.maybe_00; break;
case 0x80: maybe_cached = app->app_local->pincache.maybe_80; break;
case 0x81: maybe_cached = app->app_local->pincache.maybe_81; break;
case 0x96: maybe_cached = app->app_local->pincache.maybe_96; break;
case 0x97: maybe_cached = app->app_local->pincache.maybe_97; break;
case 0x98: maybe_cached = app->app_local->pincache.maybe_98; break;
case 0x9B: maybe_cached = app->app_local->pincache.maybe_9B; break;
default: maybe_cached = 0;
}
if (!maybe_cached)
return 0;
snprintf (pinref, sizeof pinref, "%02x", pinno);
if (pincache_get (ctrl, app_get_slot (app), "piv", pinref, r_pin))
return 0;
return 1;
}
/* 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;
}
/* Helper for verify_chv to ask for the PIN and to prepare/pad it. On
* success the result is stored at (R_PIN,R_PINLEN). */
static gpg_error_t
ask_and_prepare_chv (app_t app, ctrl_t ctrl,
int keyref, int ask_new, int remaining, int no_cache,
gpg_error_t (*pincb)(void*,const char *,char **),
void *pincb_arg, char **r_pin, unsigned int *r_pinlen,
unsigned int *r_unpaddedpinlen)
{
gpg_error_t err;
const char *label;
char *prompt;
char *pinvalue = NULL;
unsigned int pinlen;
char *pinbuffer = NULL;
int minlen, maxlen, padding, onlydigits;
*r_pin = NULL;
*r_pinlen = 0;
if (r_unpaddedpinlen)
*r_unpaddedpinlen = 0;
if (ask_new)
remaining = -1;
if (remaining != -1)
log_debug ("piv: CHV %02X has %d attempts left\n", keyref, remaining);
switch (keyref)
{
case 0x00:
minlen = 6;
maxlen = 8;
padding = 1;
onlydigits = 1;
label = (ask_new? _("|N|Please enter the new Global-PIN")
/**/ : _("||Please enter the Global-PIN of your PIV card"));
break;
case 0x80:
minlen = 6;
maxlen = 8;
padding = 1;
onlydigits = 1;
label = (ask_new? _("|N|Please enter the new PIN")
/**/ : _("||Please enter the PIN of your PIV card"));
break;
case 0x81:
minlen = 8;
maxlen = 8;
padding = 0;
onlydigits = 0;
label = (ask_new? _("|N|Please enter the new Unblocking Key")
/**/ :_("||Please enter the Unblocking Key of your PIV card"));
break;
case 0x96:
case 0x97:
case 0x98:
case 0x9B:
return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
default:
return gpg_error (GPG_ERR_INV_ID);
}
/* Ask for the PIN. */
if (!no_cache && remaining >= 3
&& pin_from_cache (app, ctrl, keyref, &pinvalue))
err = 0;
else
{
prompt = make_prompt (app, remaining, label);
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 < minlen)
{
log_error (_("PIN for is too short; minimum length is %d\n"), minlen);
if (pinvalue)
wipememory (pinvalue, pinlen);
xfree (pinvalue);
return gpg_error (GPG_ERR_BAD_PIN);
}
if (pinlen > maxlen)
{
log_error (_("PIN for is too long; maximum length is %d\n"), maxlen);
wipememory (pinvalue, pinlen);
xfree (pinvalue);
return gpg_error (GPG_ERR_BAD_PIN);
}
if (onlydigits && 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);
}
pinbuffer = xtrymalloc_secure (maxlen);
if (!pinbuffer)
{
err = gpg_error_from_syserror ();
wipememory (pinvalue, pinlen);
xfree (pinvalue);
return err;
}
memcpy (pinbuffer, pinvalue, pinlen);
wipememory (pinvalue, pinlen);
xfree (pinvalue);
if (r_unpaddedpinlen)
*r_unpaddedpinlen = pinlen;
if (padding)
{
memset (pinbuffer + pinlen, 0xff, maxlen - pinlen);
pinlen = maxlen;
}
*r_pin = pinbuffer;
*r_pinlen = pinlen;
return 0;
}
/* Verify the card holder verification identified by KEYREF. This is
* either the Application PIN or the Global PIN. If FORCE is true a
* verification is always done. */
static gpg_error_t
verify_chv (app_t app, ctrl_t ctrl, int keyref, int force,
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 *pin = NULL;
unsigned int pinlen, unpaddedpinlen;
/* 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] = keyref;
if (!iso7816_apdu_direct (app_get_slot (app), apdu, 4, 0, &sw, NULL, NULL))
{
if (!force) /* No need to verification. */
return 0; /* All fine. */
remaining = -1;
}
else if ((sw & 0xfff0) == 0x63C0)
remaining = (sw & 0x000f); /* PIN has REMAINING tries left. */
else
remaining = -1;
err = ask_and_prepare_chv (app, ctrl, keyref, 0, remaining, force,
pincb, pincb_arg,
&pin, &pinlen, &unpaddedpinlen);
if (err)
return err;
err = iso7816_verify (app_get_slot (app), keyref, pin, pinlen);
if (err)
{
log_error ("CHV %02X verification failed: %s\n",
keyref, gpg_strerror (err));
cache_pin (app, ctrl, keyref, NULL, 0);
}
else
cache_pin (app, ctrl, keyref, pin, unpaddedpinlen);
wipememory (pin, pinlen);
xfree (pin);
return err;
}
/* Handle the PASSWD command. Valid values for PWIDSTR are
* key references related to PINs; in particular:
* PIV.00 - The Global PIN
* PIV.80 - The Application PIN
* PIV.81 - The PIN Unblocking key
* The supported flags are:
* APP_CHANGE_FLAG_CLEAR Clear the PIN verification state.
* APP_CHANGE_FLAG_RESET Reset a PIN using the PUK. Only
* allowed with PIV.80.
*/
static gpg_error_t
do_change_chv (app_t app, ctrl_t ctrl, const char *pwidstr,
unsigned int flags,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg)
{
gpg_error_t err;
int keyref, targetkeyref;
unsigned char apdu[4];
unsigned int sw;
int remaining;
char *oldpin = NULL;
unsigned int oldpinlen;
char *newpin = NULL;
unsigned int newpinlen;
(void)ctrl;
/* Check for unknown flags. */
if ((flags & ~(APP_CHANGE_FLAG_CLEAR|APP_CHANGE_FLAG_RESET)))
{
err = gpg_error (GPG_ERR_UNSUPPORTED_OPERATION);
goto leave;
}
/* Parse the keyref. */
targetkeyref = keyref = parse_chv_keyref (pwidstr);
if (keyref == -1)
{
err = gpg_error (GPG_ERR_INV_ID);
goto leave;
}
cache_pin (app, ctrl, keyref, NULL, 0);
/* First see whether the special --clear mode has been requested. */
if ((flags & APP_CHANGE_FLAG_CLEAR))
{
apdu[0] = 0x00;
apdu[1] = ISO7816_VERIFY;
apdu[2] = 0xff;
apdu[3] = keyref;
err = iso7816_apdu_direct (app_get_slot (app), apdu, 4, 0,
NULL, NULL, NULL);
goto leave;
}
/* Prepare reset mode. */
if ((flags & APP_CHANGE_FLAG_RESET))
{
if (keyref == 0x81)
{
err = gpg_error (GPG_ERR_INV_ID); /* Can't reset the PUK. */
goto leave;
}
/* Set the keyref to the PUK and keep the TARGETKEYREF. */
keyref = 0x81;
}
/* Get the remaining tries count. This is done by using the check
* for verified state feature. */
apdu[0] = 0x00;
apdu[1] = ISO7816_VERIFY;
apdu[2] = 0x00;
apdu[3] = keyref;
if (!iso7816_apdu_direct (app_get_slot (app), apdu, 4, 0, &sw, NULL, NULL))
remaining = -1; /* Already verified, thus full number of tries. */
else if ((sw & 0xfff0) == 0x63C0)
remaining = (sw & 0x000f); /* PIN has REMAINING tries left. */
else
remaining = -1;
/* Ask for the old pin or puk. */
err = ask_and_prepare_chv (app, ctrl, keyref, 0, remaining, 0,
pincb, pincb_arg,
&oldpin, &oldpinlen, NULL);
if (err)
return err;
/* Verify the old pin so that we don't prompt for the new pin if the
* old is wrong. This is not possible for the PUK, though. */
if (keyref != 0x81)
{
err = iso7816_verify (app_get_slot (app), keyref, oldpin, oldpinlen);
if (err)
{
log_error ("CHV %02X verification failed: %s\n",
keyref, gpg_strerror (err));
goto leave;
}
}
/* Ask for the new pin. */
err = ask_and_prepare_chv (app, ctrl, targetkeyref, 1, -1, 0,
pincb, pincb_arg,
&newpin, &newpinlen, NULL);
if (err)
return err;
if ((flags & APP_CHANGE_FLAG_RESET))
{
char *buf = xtrymalloc_secure (oldpinlen + newpinlen);
if (!buf)
{
err = gpg_error_from_syserror ();
goto leave;
}
memcpy (buf, oldpin, oldpinlen);
memcpy (buf+oldpinlen, newpin, newpinlen);
err = iso7816_reset_retry_counter_with_rc (app_get_slot (app),
targetkeyref,
buf, oldpinlen+newpinlen);
xfree (buf);
if (err)
log_error ("resetting CHV %02X using CHV %02X failed: %s\n",
targetkeyref, keyref, gpg_strerror (err));
}
else
{
err = iso7816_change_reference_data (app_get_slot (app), keyref,
oldpin, oldpinlen,
newpin, newpinlen);
if (err)
log_error ("CHV %02X changing PIN failed: %s\n",
keyref, gpg_strerror (err));
}
leave:
xfree (oldpin);
xfree (newpin);
return err;
}
/* Perform a simple verify operation for the PIN specified by PWIDSTR.
* For valid values see do_change_chv. */
static gpg_error_t
do_check_chv (app_t app, ctrl_t ctrl, const char *pwidstr,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg)
{
int keyref;
(void)ctrl;
keyref = parse_chv_keyref (pwidstr);
if (keyref == -1)
return gpg_error (GPG_ERR_INV_ID);
return verify_chv (app, ctrl, keyref, 0, pincb, pincb_arg);
}
/* 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. If HASHALGO is not zero, the function prepends the hash's
* OID to the indata or checks that it is consistent.
*/
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_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 oidbuf[64];
size_t oidbuflen;
unsigned char *outdata = NULL;
size_t outdatalen;
const unsigned char *s;
size_t n;
int keyref, mechanism;
unsigned char *indata_buffer = NULL; /* Malloced helper. */
unsigned char *apdudata = NULL;
size_t apdudatalen;
int force_verify;
(void)ctrl;
if (!keyidstr || !*keyidstr)
{
err = gpg_error (GPG_ERR_INV_VALUE);
goto leave;
}
dobj = find_dobj_by_keyref (app, keyidstr);
if ((keyref = keyref_from_dobj (dobj)) == -1)
{
err = gpg_error (GPG_ERR_INV_ID);
goto leave;
}
/* According to table 4b of SP800-73-4 the signing key always
* requires a verify. */
switch (keyref)
{
case 0x9c: force_verify = 1; break;
default: force_verify = 0; break;
}
err = get_key_algorithm_by_dobj (app, dobj, &mechanism);
if (err)
goto leave;
/* For ECC we need to remove the ASN.1 prefix from INDATA. For RSA
* we need to add the padding and possible also the ASN.1 prefix. */
if (mechanism == PIV_ALGORITHM_ECC_P256
|| mechanism == PIV_ALGORITHM_ECC_P384)
{
int need_algo, need_digestlen;
if (mechanism == PIV_ALGORITHM_ECC_P256)
{
need_algo = GCRY_MD_SHA256;
need_digestlen = 32;
}
else
{
need_algo = GCRY_MD_SHA384;
need_digestlen = 48;
}
if (hashalgo && hashalgo != need_algo)
{
err = gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM);
log_error ("piv: hash algo %d does not match mechanism %d\n",
need_algo, mechanism);
goto leave;
}
if (indatalen > need_digestlen)
{
oidbuflen = sizeof oidbuf;
err = gcry_md_get_asnoid (need_algo, &oidbuf, &oidbuflen);
if (err)
{
err = gpg_error (GPG_ERR_INTERNAL);
log_debug ("piv: no OID for hash algo %d\n", need_algo);
goto leave;
}
if (indatalen != oidbuflen + need_digestlen
|| memcmp (indata, oidbuf, oidbuflen))
{
err = gpg_error (GPG_ERR_INV_VALUE);
log_error ("piv: bad input for signing with mechanism %d\n",
mechanism);
goto leave;
}
indata += oidbuflen;
indatalen -= oidbuflen;
}
}
else if (mechanism == PIV_ALGORITHM_RSA)
{
/* PIV requires 2048 bit RSA. */
unsigned int framelen = 2048 / 8;
unsigned char *frame;
int i;
oidbuflen = sizeof oidbuf;
if (!hashalgo)
{
/* We assume that indata already has the required
* digestinfo; thus merely prepend the padding below. */
}
else if ((err = gcry_md_get_asnoid (hashalgo, &oidbuf, &oidbuflen)))
{
log_debug ("piv: no OID for hash algo %d\n", hashalgo);
goto leave;
}
else
{
unsigned int digestlen = gcry_md_get_algo_dlen (hashalgo);
if (indatalen == digestlen)
{
/* Plain hash in INDATA; prepend the digestinfo. */
indata_buffer = xtrymalloc (oidbuflen + indatalen);
if (!indata_buffer)
{
err = gpg_error_from_syserror ();
goto leave;
}
memcpy (indata_buffer, oidbuf, oidbuflen);
memcpy (indata_buffer+oidbuflen, indata, indatalen);
indata = indata_buffer;
indatalen = oidbuflen + indatalen;
}
else if (indatalen == oidbuflen + digestlen
&& !memcmp (indata, oidbuf, oidbuflen))
; /* Correct prefix. */
else
{
err = gpg_error (GPG_ERR_INV_VALUE);
log_error ("piv: bad input for signing with RSA and hash %d\n",
hashalgo);
goto leave;
}
}
/* Now prepend the pkcs#v1.5 padding. We require at least 8
* byte of padding and 3 extra bytes for the prefix and the
* delimiting nul. */
if (!indatalen || indatalen + 8 + 4 > framelen)
{
err = gpg_error (GPG_ERR_INV_VALUE);
log_error ("piv: input does not fit into a %u bit PKCS#v1.5 frame\n",
8*framelen);
goto leave;
}
frame = xtrymalloc (framelen);
if (!frame)
{
err = gpg_error_from_syserror ();
goto leave;
}
n = 0;
frame[n++] = 0;
frame[n++] = 1; /* Block type. */
i = framelen - indatalen - 3 ;
memset (frame+n, 0xff, i);
n += i;
frame[n++] = 0; /* Delimiter. */
memcpy (frame+n, indata, indatalen);
n += indatalen;
log_assert (n == framelen);
/* And now put it into the indata_buffer. */
xfree (indata_buffer);
indata_buffer = frame;
indata = indata_buffer;
indatalen = framelen;
}
else
{
err = gpg_error (GPG_ERR_INTERNAL);
log_debug ("piv: unknown PIV mechanism %d while signing\n", mechanism);
goto leave;
}
/* Now verify the Application PIN. */
err = verify_chv (app, ctrl, 0x80, force_verify, pincb, pincb_arg);
if (err)
return err;
/* Build the Dynamic Authentication Template. */
err = concat_tlv_list (0, &apdudata, &apdudatalen,
(int)0x7c, (size_t)0, NULL, /* Constructed. */
(int)0x82, (size_t)0, "",
(int)0x81, (size_t)indatalen, indata,
(int)0, (size_t)0, NULL);
if (err)
goto leave;
/* Note: the -1 requests command chaining. */
err = iso7816_general_authenticate (app_get_slot (app), -1,
mechanism, keyref,
apdudata, (int)apdudatalen, 0,
&outdata, &outdatalen);
if (err)
goto leave;
/* Parse the response. */
if (outdatalen && *outdata == 0x7c
&& (s = find_tlv (outdata, outdatalen, 0x82, &n)))
{
if (mechanism == PIV_ALGORITHM_RSA)
{
memmove (outdata, outdata + (s - outdata), n);
outdatalen = n;
}
else /* ECC */
{
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;
}
xfree (apdudata);
xfree (indata_buffer);
return err;
}
/* AUTH for PIV cards is actually the same as SIGN. The difference
* between AUTH and SIGN is that AUTH expects that pkcs#1.5 padding
* for RSA has already been done (digestInfo part w/o the padding)
* whereas SIGN may accept a plain digest and does the padding if
* needed. This is also the reason why SIGN takes a hashalgo. */
static gpg_error_t
do_auth (app_t app, ctrl_t ctrl, const char *keyidstr,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg,
const void *indata, size_t indatalen,
unsigned char **r_outdata, size_t *r_outdatalen)
{
return do_sign (app, ctrl, keyidstr, 0, pincb, pincb_arg, indata, indatalen,
r_outdata, r_outdatalen);
}
/* Decrypt the data in (INDATA,INDATALEN) and on success store the
* mallocated result at (R_OUTDATA,R_OUTDATALEN). */
static gpg_error_t
do_decipher (app_t app, ctrl_t ctrl, 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,
unsigned int *r_info)
{
const unsigned char *indata = indata_arg;
gpg_error_t err;
data_object_t dobj;
unsigned char *outdata = NULL;
size_t outdatalen;
const unsigned char *s;
size_t n;
int keyref, mechanism;
unsigned int framelen;
unsigned char *indata_buffer = NULL; /* Malloced helper. */
unsigned char *apdudata = NULL;
size_t apdudatalen;
(void)ctrl;
if (!keyidstr || !*keyidstr)
{
err = gpg_error (GPG_ERR_INV_VALUE);
goto leave;
}
dobj = find_dobj_by_keyref (app, keyidstr);
if ((keyref = keyref_from_dobj (dobj)) == -1)
{
err = gpg_error (GPG_ERR_INV_ID);
goto leave;
}
if (keyref == 0x9A || keyref == 0x9C || keyref == 0x9E)
{
/* Signing only reference. We only allow '9D' and the retired
* cert key management DOs. */
err = gpg_error (GPG_ERR_INV_ID);
goto leave;
}
err = get_key_algorithm_by_dobj (app, dobj, &mechanism);
if (err)
goto leave;
switch (mechanism)
{
case PIV_ALGORITHM_ECC_P256:
framelen = 1+32+32;
break;
case PIV_ALGORITHM_ECC_P384:
framelen = 1+48+48;
break;
case PIV_ALGORITHM_RSA:
framelen = 2048 / 8;
break;
default:
err = gpg_error (GPG_ERR_INTERNAL);
log_debug ("piv: unknown PIV mechanism %d while decrypting\n", mechanism);
goto leave;
}
/* Check that the ciphertext has the right length; due to internal
* convey mechanism using MPIs leading zero bytes might have been
* lost. Adjust for this. Unfortunately the ciphertext might have
* also been prefixed with a leading zero to make it a positive
* number; that may be a too long frame and we need to adjust for
* this too. Note that for ECC those fixes are not reqquired
* because the first octet is always '04' to indicate an
* uncompressed point. */
if (indatalen > framelen)
{
if (mechanism == PIV_ALGORITHM_RSA
&& indatalen == framelen + 1 && !*indata)
{
indata_buffer = xtrycalloc (1, framelen);
if (!indata_buffer)
{
err = gpg_error_from_syserror ();
goto leave;
}
memcpy (indata_buffer, indata+1, framelen);
indata = indata_buffer;
indatalen = framelen;
}
else
{
err = gpg_error (GPG_ERR_INV_VALUE);
log_error ("piv: input of %zu octets too large for mechanism %d\n",
indatalen, mechanism);
goto leave;
}
}
if (indatalen < framelen)
{
indata_buffer = xtrycalloc (1, framelen);
if (!indata_buffer)
{
err = gpg_error_from_syserror ();
goto leave;
}
memcpy (indata_buffer+(framelen-indatalen), indata, indatalen);
indata = indata_buffer;
indatalen = framelen;
}
/* Now verify the Application PIN. */
err = verify_chv (app, ctrl, 0x80, 0, pincb, pincb_arg);
if (err)
return err;
/* Build the Dynamic Authentication Template. */
err = concat_tlv_list (0, &apdudata, &apdudatalen,
(int)0x7c, (size_t)0, NULL, /* Constructed. */
(int)0x82, (size_t)0, "",
mechanism == PIV_ALGORITHM_RSA?
(int)0x81 : (int)0x85, (size_t)indatalen, indata,
(int)0, (size_t)0, NULL);
if (err)
goto leave;
/* Note: the -1 requests command chaining. */
err = iso7816_general_authenticate (app_get_slot (app), -1,
mechanism, keyref,
apdudata, (int)apdudatalen, 0,
&outdata, &outdatalen);
if (err)
goto leave;
/* Parse the response. */
if (outdatalen && *outdata == 0x7c
&& (s = find_tlv (outdata, outdatalen, 0x82, &n)))
{
memmove (outdata, outdata + (s - outdata), n);
outdatalen = n;
}
else
{
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;
}
*r_info = 0;
xfree (apdudata);
xfree (indata_buffer);
return err;
}
/* Check whether a key for DOBJ already exists. We detect this by
* reading the certificate described by DOBJ. If FORCE is TRUE a
* diagnositic will be printed but no error returned if the key
* already exists. The flag GENERATING is used to select a
* diagnositic. */
static gpg_error_t
does_key_exist (app_t app, data_object_t dobj, int generating, int force)
{
void *relptr;
unsigned char *buffer;
size_t buflen;
int found;
relptr = get_one_do (app, dobj->tag, &buffer, &buflen, NULL);
found = (relptr && buflen);
xfree (relptr);
if (found && !force)
{
log_error (_("key already exists\n"));
return gpg_error (GPG_ERR_EEXIST);
}
if (found)
log_info (_("existing key will be replaced\n"));
else if (generating)
log_info (_("generating new key\n"));
else
log_info (_("writing new key\n"));
return 0;
}
/* Helper for do_writekey; here the RSA part. BUF, BUFLEN, and DEPTH
* are the current parser state of the S-expression with the key. */
static gpg_error_t
writekey_rsa (app_t app, data_object_t dobj, int keyref,
const unsigned char *buf, size_t buflen, int depth)
{
gpg_error_t err;
const unsigned char *tok;
size_t toklen;
int last_depth1, last_depth2;
const unsigned char *rsa_n = NULL;
const unsigned char *rsa_e = NULL;
const unsigned char *rsa_p = NULL;
const unsigned char *rsa_q = NULL;
unsigned char *rsa_dpm1 = NULL;
unsigned char *rsa_dqm1 = NULL;
unsigned char *rsa_qinv = NULL;
size_t rsa_n_len, rsa_e_len, rsa_p_len, rsa_q_len;
size_t rsa_dpm1_len, rsa_dqm1_len, rsa_qinv_len;
unsigned char *apdudata = NULL;
size_t apdudatalen;
unsigned char tmpl[1];
last_depth1 = depth;
while (!(err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen))
&& depth && depth >= last_depth1)
{
if (tok)
{
err = gpg_error (GPG_ERR_UNKNOWN_SEXP);
goto leave;
}
if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
goto leave;
if (tok && toklen == 1)
{
const unsigned char **mpi;
size_t *mpi_len;
switch (*tok)
{
case 'n': mpi = &rsa_n; mpi_len = &rsa_n_len; break;
case 'e': mpi = &rsa_e; mpi_len = &rsa_e_len; break;
case 'p': mpi = &rsa_p; mpi_len = &rsa_p_len; break;
case 'q': mpi = &rsa_q; mpi_len = &rsa_q_len; break;
default: mpi = NULL; mpi_len = NULL; break;
}
if (mpi && *mpi)
{
err = gpg_error (GPG_ERR_DUP_VALUE);
goto leave;
}
if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
goto leave;
if (tok && mpi)
{
/* Strip off leading zero bytes and save. */
for (;toklen && !*tok; toklen--, tok++)
;
*mpi = tok;
*mpi_len = toklen;
}
}
/* Skip until end of list. */
last_depth2 = depth;
while (!(err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen))
&& depth && depth >= last_depth2)
;
if (err)
goto leave;
}
/* Check that we have all parameters. */
if (!rsa_n || !rsa_e || !rsa_p || !rsa_q)
{
err = gpg_error (GPG_ERR_BAD_SECKEY);
goto leave;
}
/* Fixme: Shall we check whether n == pq ? */
if (opt.verbose)
log_info ("RSA private key size is %u bytes\n", (unsigned int)rsa_n_len);
/* Compute the dp, dq and u components. */
{
gcry_mpi_t mpi_e, mpi_p, mpi_q;
gcry_mpi_t mpi_dpm1 = gcry_mpi_snew (0);
gcry_mpi_t mpi_dqm1 = gcry_mpi_snew (0);
gcry_mpi_t mpi_qinv = gcry_mpi_snew (0);
gcry_mpi_t mpi_tmp = gcry_mpi_snew (0);
gcry_mpi_scan (&mpi_e, GCRYMPI_FMT_USG, rsa_e, rsa_e_len, NULL);
gcry_mpi_scan (&mpi_p, GCRYMPI_FMT_USG, rsa_p, rsa_p_len, NULL);
gcry_mpi_scan (&mpi_q, GCRYMPI_FMT_USG, rsa_q, rsa_q_len, NULL);
gcry_mpi_sub_ui (mpi_tmp, mpi_p, 1);
gcry_mpi_invm (mpi_dpm1, mpi_e, mpi_tmp);
gcry_mpi_sub_ui (mpi_tmp, mpi_q, 1);
gcry_mpi_invm (mpi_dqm1, mpi_e, mpi_tmp);
gcry_mpi_invm (mpi_qinv, mpi_q, mpi_p);
gcry_mpi_aprint (GCRYMPI_FMT_USG, &rsa_dpm1, &rsa_dpm1_len, mpi_dpm1);
gcry_mpi_aprint (GCRYMPI_FMT_USG, &rsa_dqm1, &rsa_dqm1_len, mpi_dqm1);
gcry_mpi_aprint (GCRYMPI_FMT_USG, &rsa_qinv, &rsa_qinv_len, mpi_qinv);
gcry_mpi_release (mpi_e);
gcry_mpi_release (mpi_p);
gcry_mpi_release (mpi_q);
gcry_mpi_release (mpi_dpm1);
gcry_mpi_release (mpi_dqm1);
gcry_mpi_release (mpi_qinv);
gcry_mpi_release (mpi_tmp);
}
err = concat_tlv_list (1, &apdudata, &apdudatalen,
(int)0x01, (size_t)rsa_p_len, rsa_p,
(int)0x02, (size_t)rsa_q_len, rsa_q,
(int)0x03, (size_t)rsa_dpm1_len, rsa_dpm1,
(int)0x04, (size_t)rsa_dqm1_len, rsa_dqm1,
(int)0x05, (size_t)rsa_qinv_len, rsa_qinv,
(int)0, (size_t)0, NULL);
if (err)
goto leave;
err = iso7816_send_apdu (app_get_slot (app),
-1, /* Use command chaining. */
0, /* Class */
0xfe, /* Ins: Yubikey Import Asym. Key. */
PIV_ALGORITHM_RSA, /* P1 */
keyref, /* P2 */
apdudatalen,/* Lc */
apdudata, /* data */
NULL, NULL, NULL);
if (err)
goto leave;
/* Write the public key to the cert object. */
xfree (apdudata);
err = concat_tlv_list (0, &apdudata, &apdudatalen,
(int)0x81, (size_t)rsa_n_len, rsa_n,
(int)0x82, (size_t)rsa_e_len, rsa_e,
(int)0, (size_t)0, NULL);
if (err)
goto leave;
tmpl[0] = PIV_ALGORITHM_RSA;
err = put_data (app_get_slot (app), dobj->tag,
(int)0x80, (size_t)1, tmpl,
(int)0x7f49, (size_t)apdudatalen, apdudata,
(int)0, (size_t)0, NULL);
leave:
xfree (rsa_dpm1);
xfree (rsa_dqm1);
xfree (rsa_qinv);
xfree (apdudata);
return err;
}
/* Helper for do_writekey; here the ECC part. BUF, BUFLEN, and DEPTH
* are the current parser state of the S-expression with the key. */
static gpg_error_t
writekey_ecc (app_t app, data_object_t dobj, int keyref,
const unsigned char *buf, size_t buflen, int depth)
{
gpg_error_t err;
const unsigned char *tok;
size_t toklen;
int last_depth1, last_depth2;
int mechanism = 0;
const unsigned char *ecc_q = NULL;
const unsigned char *ecc_d = NULL;
size_t ecc_q_len, ecc_d_len;
unsigned char *apdudata = NULL;
size_t apdudatalen;
unsigned char tmpl[1];
last_depth1 = depth;
while (!(err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen))
&& depth && depth >= last_depth1)
{
if (tok)
{
err = gpg_error (GPG_ERR_UNKNOWN_SEXP);
goto leave;
}
if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
goto leave;
if (tok && toklen == 5 && !memcmp (tok, "curve", 5))
{
char *name;
const char *xname;
if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
goto leave;
name = xtrymalloc (toklen+1);
if (!name)
{
err = gpg_error_from_syserror ();
goto leave;
}
memcpy (name, tok, toklen);
name[toklen] = 0;
/* Canonicalize the curve name. We use the openpgp
* functions here because Libgcrypt has no generic curve
* alias lookup feature and the PIV supported curves are
* also supported by OpenPGP. */
xname = openpgp_oid_to_curve (openpgp_curve_to_oid (name, NULL, NULL),
0);
xfree (name);
if (xname && !strcmp (xname, "nistp256"))
mechanism = PIV_ALGORITHM_ECC_P256;
else if (xname && !strcmp (xname, "nistp384"))
mechanism = PIV_ALGORITHM_ECC_P384;
else
{
err = gpg_error (GPG_ERR_UNKNOWN_CURVE);
goto leave;
}
}
else if (tok && toklen == 1)
{
const unsigned char **mpi;
size_t *mpi_len;
switch (*tok)
{
case 'q': mpi = &ecc_q; mpi_len = &ecc_q_len; break;
case 'd': mpi = &ecc_d; mpi_len = &ecc_d_len; break;
default: mpi = NULL; mpi_len = NULL; break;
}
if (mpi && *mpi)
{
err = gpg_error (GPG_ERR_DUP_VALUE);
goto leave;
}
if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
goto leave;
if (tok && mpi)
{
/* Strip off leading zero bytes and save. */
for (;toklen && !*tok; toklen--, tok++)
;
*mpi = tok;
*mpi_len = toklen;
}
}
/* Skip until end of list. */
last_depth2 = depth;
while (!(err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen))
&& depth && depth >= last_depth2)
;
if (err)
goto leave;
}
/* Check that we have all parameters. */
if (!mechanism || !ecc_q || !ecc_d)
{
err = gpg_error (GPG_ERR_BAD_SECKEY);
goto leave;
}
if (opt.verbose)
log_info ("ECC private key size is %u bytes\n", (unsigned int)ecc_d_len);
err = concat_tlv_list (1, &apdudata, &apdudatalen,
(int)0x06, (size_t)ecc_d_len, ecc_d,
(int)0, (size_t)0, NULL);
if (err)
goto leave;
err = iso7816_send_apdu (app_get_slot (app),
-1, /* Use command chaining. */
0, /* Class */
0xfe, /* Ins: Yubikey Import Asym. Key. */
mechanism, /* P1 */
keyref, /* P2 */
apdudatalen,/* Lc */
apdudata, /* data */
NULL, NULL, NULL);
if (err)
goto leave;
/* Write the public key to the cert object. */
xfree (apdudata);
err = concat_tlv_list (0, &apdudata, &apdudatalen,
(int)0x86, (size_t)ecc_q_len, ecc_q,
(int)0, (size_t)0, NULL);
if (err)
goto leave;
tmpl[0] = mechanism;
err = put_data (app_get_slot (app), dobj->tag,
(int)0x80, (size_t)1, tmpl,
(int)0x7f49, (size_t)apdudatalen, apdudata,
(int)0, (size_t)0, NULL);
leave:
xfree (apdudata);
return err;
}
/* Write a key to a slot. This command requires proprietary
* extensions of the PIV specification and is thus only implemnted for
* supported card types. The input is a canonical encoded
* S-expression with the secret key in KEYDATA and its length (for
* assertion) in KEYDATALEN. KEYREFSTR needs to be the usual 2
* hexdigit slot number prefixed with "PIV." PINCB and PINCB_ARG are
* not used for PIV cards.
*
* Supported FLAGS are:
* APP_WRITEKEY_FLAG_FORCE Overwrite existing key.
*/
static gpg_error_t
do_writekey (app_t app, ctrl_t ctrl,
const char *keyrefstr, unsigned int flags,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg,
const unsigned char *keydata, size_t keydatalen)
{
gpg_error_t err;
int force = !!(flags & APP_WRITEKEY_FLAG_FORCE);
data_object_t dobj;
int keyref;
const unsigned char *buf, *tok;
size_t buflen, toklen;
int depth;
(void)ctrl;
(void)pincb;
(void)pincb_arg;
if (!app->app_local->flags.yubikey)
{
err = gpg_error (GPG_ERR_NOT_SUPPORTED);
goto leave;
}
/* Check keyref and test whether a key already exists. */
dobj = find_dobj_by_keyref (app, keyrefstr);
if ((keyref = keyref_from_dobj (dobj)) == -1)
{
err = gpg_error (GPG_ERR_INV_ID);
goto leave;
}
err = does_key_exist (app, dobj, 0, force);
if (err)
goto leave;
/* Parse the S-expression with the key. */
buf = keydata;
buflen = keydatalen;
depth = 0;
if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
goto leave;
if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
goto leave;
if (!tok || toklen != 11 || memcmp ("private-key", tok, toklen))
{
if (!tok)
;
else if (toklen == 21 && !memcmp ("protected-private-key", tok, toklen))
log_info ("protected-private-key passed to writekey\n");
else if (toklen == 20 && !memcmp ("shadowed-private-key", tok, toklen))
log_info ("shadowed-private-key passed to writekey\n");
err = gpg_error (GPG_ERR_BAD_SECKEY);
goto leave;
}
if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
goto leave;
if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
goto leave;
/* First clear an existing key. We do this by writing an empty 7f49
* tag. This will return GPG_ERR_NO_PUBKEY on a later read. */
flush_cached_data (app, dobj->tag);
err = put_data (app_get_slot (app), dobj->tag,
(int)0x7f49, (size_t)0, "",
(int)0, (size_t)0, NULL);
if (err)
{
log_error ("piv: failed to clear the cert DO %s: %s\n",
dobj->keyref, gpg_strerror (err));
goto leave;
}
/* Divert to the algo specific implementation. */
if (tok && toklen == 3 && memcmp ("rsa", tok, toklen) == 0)
err = writekey_rsa (app, dobj, keyref, buf, buflen, depth);
else if (tok && toklen == 3 && memcmp ("ecc", tok, toklen) == 0)
err = writekey_ecc (app, dobj, keyref, buf, buflen, depth);
else
err = gpg_error (GPG_ERR_WRONG_PUBKEY_ALGO);
if (err)
{
/* A PIN is not required, thus use a better error code. */
if (gpg_err_code (err) == GPG_ERR_BAD_PIN)
err = gpg_error (GPG_ERR_NO_AUTH);
log_error (_("failed to store the key: %s\n"), gpg_strerror (err));
}
leave:
return err;
}
/* Parse an RSA response object, consisting of the content of tag
* 0x7f49, into a gcrypt s-expression object and store that R_SEXP.
* On error NULL is stored at R_SEXP. */
static gpg_error_t
genkey_parse_rsa (const unsigned char *data, size_t datalen,
gcry_sexp_t *r_sexp)
{
gpg_error_t err;
const unsigned char *m, *e;
unsigned char *mbuf = NULL;
unsigned char *ebuf = NULL;
size_t mlen, elen;
*r_sexp = NULL;
m = find_tlv (data, datalen, 0x0081, &mlen);
if (!m)
{
log_error (_("response does not contain the RSA modulus\n"));
err = gpg_error (GPG_ERR_CARD);
goto leave;
}
e = find_tlv (data, datalen, 0x0082, &elen);
if (!e)
{
log_error (_("response does not contain the RSA public exponent\n"));
err = gpg_error (GPG_ERR_CARD);
goto leave;
}
for (; mlen && !*m; mlen--, m++) /* Strip leading zeroes */
;
for (; elen && !*e; elen--, e++) /* Strip leading zeroes */
;
mbuf = xtrymalloc (mlen + 1);
if (!mbuf)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Prepend numbers with a 0 if needed. */
if (mlen && (*m & 0x80))
{
*mbuf = 0;
memcpy (mbuf+1, m, mlen);
mlen++;
}
else
memcpy (mbuf, m, mlen);
ebuf = xtrymalloc (elen + 1);
if (!ebuf)
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Prepend numbers with a 0 if needed. */
if (elen && (*e & 0x80))
{
*ebuf = 0;
memcpy (ebuf+1, e, elen);
elen++;
}
else
memcpy (ebuf, e, elen);
err = gcry_sexp_build (r_sexp, NULL, "(public-key(rsa(n%b)(e%b)))",
(int)mlen, mbuf, (int)elen, ebuf);
leave:
xfree (mbuf);
xfree (ebuf);
return err;
}
/* Parse an ECC response object, consisting of the content of tag
* 0x7f49, into a gcrypt s-expression object and store that R_SEXP.
* On error NULL is stored at R_SEXP. MECHANISM specifies the
* curve. */
static gpg_error_t
genkey_parse_ecc (const unsigned char *data, size_t datalen, int mechanism,
gcry_sexp_t *r_sexp)
{
gpg_error_t err;
const unsigned char *ecc_q;
size_t ecc_qlen;
const char *curve;
*r_sexp = NULL;
ecc_q = find_tlv (data, datalen, 0x0086, &ecc_qlen);
if (!ecc_q)
{
log_error (_("response does not contain the EC public key\n"));
err = gpg_error (GPG_ERR_CARD);
goto leave;
}
if (mechanism == PIV_ALGORITHM_ECC_P256)
curve = "nistp256";
else if (mechanism == PIV_ALGORITHM_ECC_P384)
curve = "nistp384";
else
{
err = gpg_error (GPG_ERR_BUG); /* Call with wrong parameters. */
goto leave;
}
err = gcry_sexp_build (r_sexp, NULL, "(public-key(ecc(curve%s)(q%b)))",
curve, (int)ecc_qlen, ecc_q);
leave:
return err;
}
/* Create a new keypair for KEYREF. If KEYTYPE is NULL a default
* keytype is selected, else it may be one of the strings:
* "rsa2048", "nistp256, or "nistp384".
*
* Supported FLAGS are:
* APP_GENKEY_FLAG_FORCE Overwrite existing key.
*
* Note that CREATETIME is not used for PIV cards.
*
* Because there seems to be no way to read the public key we need to
* retrieve it from a certificate. The GnuPG system however requires
* the use of app_readkey to fetch the public key from the card to
* create the certificate; to support this we temporary store the
* generated public key in the local context for use by app_readkey.
*/
static gpg_error_t
do_genkey (app_t app, ctrl_t ctrl, const char *keyrefstr, const char *keytype,
unsigned int flags, time_t createtime,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg)
{
gpg_error_t err;
data_object_t dobj;
unsigned char *buffer = NULL;
size_t buflen;
int force = !!(flags & APP_GENKEY_FLAG_FORCE);
int mechanism;
time_t start_at;
int keyref;
unsigned char tmpl[5];
size_t tmpllen;
const unsigned char *keydata;
size_t keydatalen;
(void)ctrl;
(void)createtime;
(void)pincb;
(void)pincb_arg;
if (!keytype)
keytype = "rsa2048";
if (!strcmp (keytype, "rsa2048"))
mechanism = PIV_ALGORITHM_RSA;
else if (!strcmp (keytype, "nistp256"))
mechanism = PIV_ALGORITHM_ECC_P256;
else if (!strcmp (keytype, "nistp384"))
mechanism = PIV_ALGORITHM_ECC_P384;
else
return gpg_error (GPG_ERR_UNKNOWN_CURVE);
/* We flush the cache to increase the I/O traffic before a key
* generation. This _might_ help the card to gather more entropy
* and is anyway a prerequisite for does_key_exist. */
flush_cached_data (app, 0);
/* Check whether a key already exists. */
dobj = find_dobj_by_keyref (app, keyrefstr);
if ((keyref = keyref_from_dobj (dobj)) == -1)
{
err = gpg_error (GPG_ERR_INV_ID);
goto leave;
}
err = does_key_exist (app, dobj, 1, force);
if (err)
goto leave;
/* Create the key. */
log_info (_("please wait while key is being generated ...\n"));
start_at = time (NULL);
tmpl[0] = 0xac;
tmpl[1] = 3;
tmpl[2] = 0x80;
tmpl[3] = 1;
tmpl[4] = mechanism;
tmpllen = 5;
err = iso7816_generate_keypair (app_get_slot (app), 0, 0, keyref,
tmpl, tmpllen, 0, &buffer, &buflen);
if (err)
{
/* A PIN is not required, thus use a better error code. */
if (gpg_err_code (err) == GPG_ERR_BAD_PIN)
err = gpg_error (GPG_ERR_NO_AUTH);
log_error (_("generating key failed\n"));
return err;
}
{
int nsecs = (int)(time (NULL) - start_at);
log_info (ngettext("key generation completed (%d second)\n",
"key generation completed (%d seconds)\n",
nsecs), nsecs);
}
/* Parse the result and store it as an s-expression in a dedicated
* cache for later retrieval by app_readkey. */
keydata = find_tlv (buffer, buflen, 0x7F49, &keydatalen);
if (!keydata || !keydatalen)
{
err = gpg_error (GPG_ERR_CARD);
log_error (_("response does not contain the public key data\n"));
goto leave;
}
tmpl[0] = mechanism;
flush_cached_data (app, dobj->tag);
err = put_data (app_get_slot (app), dobj->tag,
(int)0x80, (size_t)1, tmpl,
(int)0x7f49, (size_t)keydatalen, keydata,
(int)0, (size_t)0, NULL);
if (err)
{
log_error ("piv: failed to write key to the cert DO %s: %s\n",
dobj->keyref, gpg_strerror (err));
goto leave;
}
leave:
xfree (buffer);
return err;
}
/* Write the certificate (CERT,CERTLEN) to the card at CERTREFSTR.
* CERTREFSTR is either the OID of the certificate's container data
* object or of the form "PIV.<two_hexdigit_keyref>". */
static gpg_error_t
do_writecert (app_t app, ctrl_t ctrl,
const char *certrefstr,
gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg,
const unsigned char *cert, size_t certlen)
{
gpg_error_t err;
data_object_t dobj;
unsigned char *pk = NULL;
unsigned char *orig_pk = NULL;
size_t pklen, orig_pklen;
(void)ctrl;
(void)pincb; /* Not used; instead authentication is needed. */
(void)pincb_arg;
if (!certlen)
return gpg_error (GPG_ERR_INV_CERT_OBJ);
dobj = find_dobj_by_keyref (app, certrefstr);
if (!dobj || !*dobj->keyref)
return gpg_error (GPG_ERR_INV_ID);
flush_cached_data (app, dobj->tag);
/* Check that the public key parameters from the certificate match
* an already stored key. Note that we do not allow writing a
* certificate if no key has yet been created (GPG_ERR_NOT_FOUND) or
* if there is a problem reading the public key from the certificate
* GPG_ERR_NO_PUBKEY). We enforce this because otherwise the only
* way to detect whether a key exists is by trying to use that
* key. */
err = do_readkey (app, ctrl, certrefstr, 0, &orig_pk, &orig_pklen);
if (err)
{
if (gpg_err_code (err) == GPG_ERR_NOT_FOUND)
err = gpg_error (GPG_ERR_NO_SECKEY); /* Use a better error code. */
goto leave;
}
/* Compare pubkeys. */
err = app_help_pubkey_from_cert (cert, certlen, &pk, &pklen);
if (err)
goto leave; /* No public key in new certificate. */
if (orig_pklen != pklen || memcmp (orig_pk, pk, pklen))
{
err = gpg_error (GPG_ERR_CONFLICT);
goto leave;
}
err = put_data (app_get_slot (app), dobj->tag,
(int)0x70, (size_t)certlen, cert,/* Certificate */
(int)0x71, (size_t)1, "", /* No compress */
(int)0xfe, (size_t)0, "", /* Empty LRC. */
(int)0, (size_t)0, NULL);
/* A PIN is not required, thus use a better error code. */
if (gpg_err_code (err) == GPG_ERR_BAD_PIN)
err = gpg_error (GPG_ERR_NO_AUTH);
if (err)
log_error ("piv: failed to write cert to %s: %s\n",
dobj->keyref, gpg_strerror (err));
leave:
xfree (pk);
xfree (orig_pk);
return err;
}
/* Process the various keygrip based info requests. */
static gpg_error_t
do_with_keygrip (app_t app, ctrl_t ctrl, int action,
const char *want_keygripstr, int capability)
{
gpg_error_t err;
char *keygripstr = NULL;
char *serialno = NULL;
char idbuf[20];
int data = 0;
int i, tag, dummy_got_cert;
/* First a quick check for valid parameters. */
switch (action)
{
case KEYGRIP_ACTION_LOOKUP:
if (!want_keygripstr)
{
err = gpg_error (GPG_ERR_NOT_FOUND);
goto leave;
}
break;
case KEYGRIP_ACTION_SEND_DATA:
data = 1;
break;
case KEYGRIP_ACTION_WRITE_STATUS:
break;
default:
err = gpg_error (GPG_ERR_INV_ARG);
goto leave;
}
/* Allocate the s/n string if needed. */
if (action != KEYGRIP_ACTION_LOOKUP)
{
serialno = app_get_serialno (app);
if (!serialno)
{
err = gpg_error_from_syserror ();
goto leave;
}
}
for (i = 0; (tag = data_objects[i].tag); i++)
{
if (!data_objects[i].keypair)
continue;
xfree (keygripstr);
if (get_keygrip_by_tag (app, tag, &keygripstr, &dummy_got_cert))
continue;
if (action == KEYGRIP_ACTION_LOOKUP)
{
if (!strcmp (keygripstr, want_keygripstr))
{
err = 0; /* Found */
goto leave;
}
}
else if (!want_keygripstr || !strcmp (keygripstr, want_keygripstr))
{
if (capability == 1)
{
if (strcmp (data_objects[i].keyref, "9C"))
continue;
}
if (capability == 2)
{
if (strcmp (data_objects[i].keyref, "9D"))
continue;
}
if (capability == 3)
{
if (strcmp (data_objects[i].keyref, "9A"))
continue;
}
snprintf (idbuf, sizeof idbuf, "PIV.%s", data_objects[i].keyref);
send_keyinfo (ctrl, data, keygripstr, serialno, idbuf);
if (want_keygripstr)
{
err = 0; /* Found */
goto leave;
}
}
}
/* Return an error so that the dispatcher keeps on looping over the
* other applications. For clarity we use a different error code
* when listing all keys. Note that in lookup mode WANT_KEYGRIPSTR
* is not NULL. */
if (!want_keygripstr)
err = gpg_error (GPG_ERR_TRUE);
else
err = gpg_error (GPG_ERR_NOT_FOUND);
leave:
xfree (keygripstr);
xfree (serialno);
return err;
}
/* Prepare a reselect of another application. This is used by cards
* which support on-the-fly switching between applications. The
* function is called to give us a chance to save state for a future
* reselect of us again. */
static gpg_error_t
do_prep_reselect (app_t app, ctrl_t ctrl)
{
gpg_error_t err;
(void)app;
(void)ctrl;
err = 0;
return err;
}
/* Reselect the application. This is used by cards which support
* on-the-fly switching between applications. */
static gpg_error_t
do_reselect (app_t app, ctrl_t ctrl)
{
gpg_error_t err;
(void)ctrl;
/* An extra check which should not be necessary because the caller
* should have made sure that a re-select is only called for
* appropriate cards. */
if (!app->app_local->flags.yubikey)
return gpg_error (GPG_ERR_NOT_SUPPORTED);
err = iso7816_select_application (app_get_slot (app),
piv_aid, sizeof piv_aid, 0x0001);
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)
{
int slot = app_get_slot (app);
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, piv_aid, sizeof piv_aid, 0x0001,
&apt, &aptlen);
if (err)
goto leave;
app->apptype = 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, piv_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->appversion = ((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, piv_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;
}
if (app->card->cardtype == CARDTYPE_YUBIKEY)
app->app_local->flags.yubikey = 1;
/* FIXME: Parse the optional and conditional DOs in the APT. */
if (opt.verbose)
dump_all_do (slot);
app->fnc.deinit = do_deinit;
app->fnc.prep_reselect = do_prep_reselect;
app->fnc.reselect = do_reselect;
app->fnc.learn_status = do_learn_status;
app->fnc.readcert = do_readcert;
app->fnc.readkey = do_readkey;
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_chv;
app->fnc.check_pin = do_check_chv;
app->fnc.with_keygrip = do_with_keygrip;
leave:
xfree (apt);
if (err)
do_deinit (app);
return err;
}
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