openssh-portable/scard.c

373 lines
8.1 KiB
C

/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef SMARTCARD
#include "includes.h"
RCSID("$OpenBSD: scard.c,v 1.13 2001/08/02 16:14:05 jakob Exp $");
#include <openssl/engine.h>
#include <sectok.h>
#include "key.h"
#include "log.h"
#include "xmalloc.h"
#include "scard.h"
#define CLA_SSH 0x05
#define INS_DECRYPT 0x10
#define INS_GET_KEYLENGTH 0x20
#define INS_GET_PUBKEY 0x30
#define INS_GET_RESPONSE 0xc0
#define MAX_BUF_SIZE 256
static int sc_fd = -1;
static char *sc_reader_id = NULL;
static int cla = 0x00; /* class */
/* interface to libsectok */
static int
sc_open(void)
{
int sw;
if (sc_fd >= 0)
return sc_fd;
sc_fd = sectok_friendly_open(sc_reader_id, STONOWAIT, &sw);
if (sc_fd < 0) {
error("sectok_open failed: %s", sectok_get_sw(sw));
return SCARD_ERROR_FAIL;
}
if (! sectok_cardpresent(sc_fd)) {
debug("smartcard in reader %s not present, skipping",
sc_reader_id);
sc_close();
return SCARD_ERROR_NOCARD;
}
if (sectok_reset(sc_fd, 0, NULL, &sw) <= 0) {
error("sectok_reset failed: %s", sectok_get_sw(sw));
sc_fd = -1;
return SCARD_ERROR_FAIL;
}
if ((cla = cyberflex_inq_class(sc_fd)) < 0)
cla = 0;
debug("sc_open ok %d", sc_fd);
return sc_fd;
}
static int
sc_enable_applet(void)
{
static u_char aid[] = {0xfc, 0x53, 0x73, 0x68, 0x2e, 0x62, 0x69, 0x6e};
int sw = 0;
/* select applet id */
sectok_apdu(sc_fd, cla, 0xa4, 0x04, 0, sizeof aid, aid, 0, NULL, &sw);
if (!sectok_swOK(sw)) {
error("sectok_apdu failed: %s", sectok_get_sw(sw));
sc_close();
return -1;
}
return 0;
}
static int
sc_init(void)
{
int status;
status = sc_open();
if (status == SCARD_ERROR_NOCARD) {
return SCARD_ERROR_NOCARD;
}
if (status < 0 ) {
error("sc_open failed");
return status;
}
if (sc_enable_applet() < 0) {
error("sc_enable_applet failed");
return SCARD_ERROR_APPLET;
}
return 0;
}
static int
sc_read_pubkey(Key * k)
{
u_char buf[2], *n;
char *p;
int len, sw, status;
len = sw = 0;
if (sc_fd < 0) {
status = sc_init();
if (status < 0 )
return status;
}
/* get key size */
sectok_apdu(sc_fd, CLA_SSH, INS_GET_KEYLENGTH, 0, 0, 0, NULL,
sizeof(buf), buf, &sw);
if (!sectok_swOK(sw)) {
error("could not obtain key length: %s", sectok_get_sw(sw));
sc_close();
return -1;
}
len = (buf[0] << 8) | buf[1];
len /= 8;
debug("INS_GET_KEYLENGTH: len %d sw %s", len, sectok_get_sw(sw));
n = xmalloc(len);
/* get n */
sectok_apdu(sc_fd, CLA_SSH, INS_GET_PUBKEY, 0, 0, 0, NULL, len, n, &sw);
if (!sectok_swOK(sw)) {
error("could not obtain public key: %s", sectok_get_sw(sw));
xfree(n);
return -1;
}
debug("INS_GET_KEYLENGTH: sw %s", sectok_get_sw(sw));
if (BN_bin2bn(n, len, k->rsa->n) == NULL) {
error("c_read_pubkey: BN_bin2bn failed");
xfree(n);
sc_close();
return -1;
}
xfree(n);
/* currently the java applet just stores 'n' */
if (!BN_set_word(k->rsa->e, 35)) {
error("c_read_pubkey: BN_set_word(e, 35) failed");
return -1;
}
p = key_fingerprint(k, SSH_FP_MD5, SSH_FP_HEX);
debug("fingerprint %d %s", key_size(k), p);
xfree(p);
return 0;
}
/* private key operations */
static int
sc_private_decrypt(int flen, u_char *from, u_char *to, RSA *rsa, int padding)
{
u_char *padded = NULL;
int sw, len, olen, status;
debug("sc_private_decrypt called");
olen = len = sw = 0;
if (sc_fd < 0) {
status = sc_init();
if (status < 0 )
goto err;
}
if (padding != RSA_PKCS1_PADDING)
goto err;
len = BN_num_bytes(rsa->n);
padded = xmalloc(len);
sectok_apdu(sc_fd, CLA_SSH, INS_DECRYPT, 0, 0, len, from, 0, NULL, &sw);
if (!sectok_swOK(sw)) {
error("sc_private_decrypt: INS_DECRYPT failed: %s",
sectok_get_sw(sw));
sc_close();
goto err;
}
sectok_apdu(sc_fd, CLA_SSH, INS_GET_RESPONSE, 0, 0, 0, NULL,
len, padded, &sw);
if (!sectok_swOK(sw)) {
error("sc_private_decrypt: INS_GET_RESPONSE failed: %s",
sectok_get_sw(sw));
sc_close();
goto err;
}
olen = RSA_padding_check_PKCS1_type_2(to, len, padded + 1, len - 1,
len);
err:
if (padded)
xfree(padded);
return (olen >= 0 ? olen : status);
}
static int
sc_private_encrypt(int flen, u_char *from, u_char *to, RSA *rsa, int padding)
{
u_char *padded = NULL;
int sw, len, status;
len = sw = 0;
if (sc_fd < 0) {
status = sc_init();
if (status < 0 )
goto err;
}
if (padding != RSA_PKCS1_PADDING)
goto err;
debug("sc_private_encrypt called");
len = BN_num_bytes(rsa->n);
padded = xmalloc(len);
if (RSA_padding_add_PKCS1_type_1(padded, len, from, flen) <= 0) {
error("RSA_padding_add_PKCS1_type_1 failed");
goto err;
}
sectok_apdu(sc_fd, CLA_SSH, INS_DECRYPT, 0, 0, len, padded, 0, NULL, &sw);
if (!sectok_swOK(sw)) {
error("sc_private_decrypt: INS_DECRYPT failed: %s",
sectok_get_sw(sw));
sc_close();
goto err;
}
sectok_apdu(sc_fd, CLA_SSH, INS_GET_RESPONSE, 0, 0, 0, NULL,
len, to, &sw);
if (!sectok_swOK(sw)) {
error("sc_private_decrypt: INS_GET_RESPONSE failed: %s",
sectok_get_sw(sw));
sc_close();
goto err;
}
err:
if (padded)
xfree(padded);
return (len >= 0 ? len : status);
}
/* called on free */
static int (*orig_finish)(RSA *rsa) = NULL;
static int
sc_finish(RSA *rsa)
{
if (orig_finish)
orig_finish(rsa);
sc_close();
return 1;
}
/* engine for overloading private key operations */
static ENGINE *smart_engine = NULL;
static RSA_METHOD smart_rsa =
{
"sectok",
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
0,
NULL,
};
ENGINE *
sc_get_engine(void)
{
RSA_METHOD *def;
def = RSA_get_default_openssl_method();
/* overload */
smart_rsa.rsa_priv_enc = sc_private_encrypt;
smart_rsa.rsa_priv_dec = sc_private_decrypt;
/* save original */
orig_finish = def->finish;
smart_rsa.finish = sc_finish;
/* just use the OpenSSL version */
smart_rsa.rsa_pub_enc = def->rsa_pub_enc;
smart_rsa.rsa_pub_dec = def->rsa_pub_dec;
smart_rsa.rsa_mod_exp = def->rsa_mod_exp;
smart_rsa.bn_mod_exp = def->bn_mod_exp;
smart_rsa.init = def->init;
smart_rsa.flags = def->flags;
smart_rsa.app_data = def->app_data;
smart_rsa.rsa_sign = def->rsa_sign;
smart_rsa.rsa_verify = def->rsa_verify;
smart_engine = ENGINE_new();
ENGINE_set_id(smart_engine, "sectok");
ENGINE_set_name(smart_engine, "libsectok");
ENGINE_set_RSA(smart_engine, &smart_rsa);
ENGINE_set_DSA(smart_engine, DSA_get_default_openssl_method());
ENGINE_set_DH(smart_engine, DH_get_default_openssl_method());
ENGINE_set_RAND(smart_engine, RAND_SSLeay());
ENGINE_set_BN_mod_exp(smart_engine, BN_mod_exp);
return smart_engine;
}
void
sc_close(void)
{
if (sc_fd >= 0) {
sectok_close(sc_fd);
sc_fd = -1;
}
}
Key *
sc_get_key(const char *id)
{
Key *k;
int status;
if (sc_reader_id != NULL)
xfree(sc_reader_id);
sc_reader_id = xstrdup(id);
k = key_new(KEY_RSA);
if (k == NULL) {
return NULL;
}
status = sc_read_pubkey(k);
if (status == SCARD_ERROR_NOCARD) {
key_free(k);
return NULL;
}
if (status < 0 ) {
error("sc_read_pubkey failed");
key_free(k);
return NULL;
}
return k;
sc_close();
}
#endif /* SMARTCARD */