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/*
* Copyright (c) 2002 Juha Yrjölä. All rights reserved.
* Copyright (c) 2001 Markus Friedl.
*
* 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.
*/
#include "includes.h"
#if defined(SMARTCARD) && defined(USE_OPENSC)
#include <sys/types.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
#include <stdarg.h>
#include <opensc/opensc.h>
#include <opensc/pkcs15.h>
#include "key.h"
#include "log.h"
#include "xmalloc.h"
#include "misc.h"
#include "scard.h"
#if OPENSSL_VERSION_NUMBER < 0x00907000L && defined(CRYPTO_LOCK_ENGINE)
#define USE_ENGINE
#define RSA_get_default_method RSA_get_default_openssl_method
#else
#endif
#ifdef USE_ENGINE
#include <openssl/engine.h>
#define sc_get_rsa sc_get_engine
#else
#define sc_get_rsa sc_get_rsa_method
#endif
static int sc_reader_id;
static sc_context_t *ctx = NULL;
static sc_card_t *card = NULL;
static sc_pkcs15_card_t *p15card = NULL;
static char *sc_pin = NULL;
struct sc_priv_data
{
struct sc_pkcs15_id cert_id;
int ref_count;
};
void
sc_close(void)
{
if (p15card) {
sc_pkcs15_unbind(p15card);
p15card = NULL;
}
if (card) {
sc_disconnect_card(card, 0);
card = NULL;
}
if (ctx) {
sc_release_context(ctx);
ctx = NULL;
}
}
static int
sc_init(void)
{
int r;
r = sc_establish_context(&ctx, "openssh");
if (r)
goto err;
if (sc_reader_id >= ctx->reader_count) {
r = SC_ERROR_NO_READERS_FOUND;
error("Illegal reader number %d (max %d)", sc_reader_id,
ctx->reader_count -1);
goto err;
}
r = sc_connect_card(ctx->reader[sc_reader_id], 0, &card);
if (r)
goto err;
r = sc_pkcs15_bind(card, &p15card);
if (r)
goto err;
return 0;
err:
sc_close();
return r;
}
/* private key operations */
static int
sc_prkey_op_init(RSA *rsa, struct sc_pkcs15_object **key_obj_out,
unsigned int usage)
{
int r;
struct sc_priv_data *priv;
struct sc_pkcs15_object *key_obj;
struct sc_pkcs15_prkey_info *key;
struct sc_pkcs15_object *pin_obj;
struct sc_pkcs15_pin_info *pin;
priv = (struct sc_priv_data *) RSA_get_app_data(rsa);
if (priv == NULL)
return -1;
if (p15card == NULL) {
sc_close();
r = sc_init();
if (r) {
error("SmartCard init failed: %s", sc_strerror(r));
goto err;
}
}
r = sc_pkcs15_find_prkey_by_id_usage(p15card, &priv->cert_id,
usage, &key_obj);
if (r) {
error("Unable to find private key from SmartCard: %s",
sc_strerror(r));
goto err;
}
key = key_obj->data;
r = sc_pkcs15_find_pin_by_auth_id(p15card, &key_obj->auth_id,
&pin_obj);
if (r == SC_ERROR_OBJECT_NOT_FOUND) {
/* no pin required */
r = sc_lock(card);
if (r) {
error("Unable to lock smartcard: %s", sc_strerror(r));
goto err;
}
*key_obj_out = key_obj;
return 0;
} else if (r) {
error("Unable to find PIN object from SmartCard: %s",
sc_strerror(r));
goto err;
}
pin = pin_obj->data;
r = sc_lock(card);
if (r) {
error("Unable to lock smartcard: %s", sc_strerror(r));
goto err;
}
if (sc_pin != NULL) {
r = sc_pkcs15_verify_pin(p15card, pin, sc_pin,
strlen(sc_pin));
if (r) {
sc_unlock(card);
error("PIN code verification failed: %s",
sc_strerror(r));
goto err;
}
}
*key_obj_out = key_obj;
return 0;
err:
sc_close();
return -1;
}
#define SC_USAGE_DECRYPT SC_PKCS15_PRKEY_USAGE_DECRYPT | \
SC_PKCS15_PRKEY_USAGE_UNWRAP
static int
sc_private_decrypt(int flen, u_char *from, u_char *to, RSA *rsa,
int padding)
{
struct sc_pkcs15_object *key_obj;
int r;
if (padding != RSA_PKCS1_PADDING)
return -1;
r = sc_prkey_op_init(rsa, &key_obj, SC_USAGE_DECRYPT);
if (r)
return -1;
r = sc_pkcs15_decipher(p15card, key_obj, SC_ALGORITHM_RSA_PAD_PKCS1,
from, flen, to, flen);
sc_unlock(card);
if (r < 0) {
error("sc_pkcs15_decipher() failed: %s", sc_strerror(r));
goto err;
}
return r;
err:
sc_close();
return -1;
}
#define SC_USAGE_SIGN SC_PKCS15_PRKEY_USAGE_SIGN | \
SC_PKCS15_PRKEY_USAGE_SIGNRECOVER
static int
sc_sign(int type, u_char *m, unsigned int m_len,
unsigned char *sigret, unsigned int *siglen, RSA *rsa)
{
struct sc_pkcs15_object *key_obj;
int r;
unsigned long flags = 0;
/* XXX: sc_prkey_op_init will search for a pkcs15 private
* key object with the sign or signrecover usage flag set.
* If the signing key has only the non-repudiation flag set
* the key will be rejected as using a non-repudiation key
* for authentication is not recommended. Note: This does not
* prevent the use of a non-repudiation key for authentication
* if the sign or signrecover flag is set as well.
*/
r = sc_prkey_op_init(rsa, &key_obj, SC_USAGE_SIGN);
if (r)
return -1;
/* FIXME: length of sigret correct? */
/* FIXME: check 'type' and modify flags accordingly */
flags = SC_ALGORITHM_RSA_PAD_PKCS1 | SC_ALGORITHM_RSA_HASH_SHA1;
r = sc_pkcs15_compute_signature(p15card, key_obj, flags,
m, m_len, sigret, RSA_size(rsa));
sc_unlock(card);
if (r < 0) {
error("sc_pkcs15_compute_signature() failed: %s",
sc_strerror(r));
goto err;
}
*siglen = r;
return 1;
err:
sc_close();
return 0;
}
static int
sc_private_encrypt(int flen, u_char *from, u_char *to, RSA *rsa,
int padding)
{
error("Private key encryption not supported");
return -1;
}
/* called on free */
static int (*orig_finish)(RSA *rsa) = NULL;
static int
sc_finish(RSA *rsa)
{
struct sc_priv_data *priv;
priv = RSA_get_app_data(rsa);
priv->ref_count--;
if (priv->ref_count == 0) {
free(priv);
sc_close();
}
if (orig_finish)
orig_finish(rsa);
return 1;
}
/* engine for overloading private key operations */
static RSA_METHOD *
sc_get_rsa_method(void)
{
static RSA_METHOD smart_rsa;
const RSA_METHOD *def = RSA_get_default_method();
/* use the OpenSSL version */
memcpy(&smart_rsa, def, sizeof(smart_rsa));
smart_rsa.name = "opensc";
/* overload */
smart_rsa.rsa_priv_enc = sc_private_encrypt;
smart_rsa.rsa_priv_dec = sc_private_decrypt;
smart_rsa.rsa_sign = sc_sign;
/* save original */
orig_finish = def->finish;
smart_rsa.finish = sc_finish;
return &smart_rsa;
}
#ifdef USE_ENGINE
static ENGINE *
sc_get_engine(void)
{
static ENGINE *smart_engine = NULL;
if ((smart_engine = ENGINE_new()) == NULL)
fatal("ENGINE_new failed");
ENGINE_set_id(smart_engine, "opensc");
ENGINE_set_name(smart_engine, "OpenSC");
ENGINE_set_RSA(smart_engine, sc_get_rsa_method());
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;
}
#endif
static void
convert_rsa_to_rsa1(Key * in, Key * out)
{
struct sc_priv_data *priv;
out->rsa->flags = in->rsa->flags;
out->flags = in->flags;
RSA_set_method(out->rsa, RSA_get_method(in->rsa));
BN_copy(out->rsa->n, in->rsa->n);
BN_copy(out->rsa->e, in->rsa->e);
priv = RSA_get_app_data(in->rsa);
priv->ref_count++;
RSA_set_app_data(out->rsa, priv);
return;
}
static int
sc_read_pubkey(Key * k, const struct sc_pkcs15_object *cert_obj)
{
int r;
sc_pkcs15_cert_t *cert = NULL;
struct sc_priv_data *priv = NULL;
sc_pkcs15_cert_info_t *cinfo = cert_obj->data;
X509 *x509 = NULL;
EVP_PKEY *pubkey = NULL;
u8 *p;
char *tmp;
debug("sc_read_pubkey() with cert id %02X", cinfo->id.value[0]);
r = sc_pkcs15_read_certificate(p15card, cinfo, &cert);
if (r) {
logit("Certificate read failed: %s", sc_strerror(r));
goto err;
}
x509 = X509_new();
if (x509 == NULL) {
r = -1;
goto err;
}
p = cert->data;
if (!d2i_X509(&x509, &p, cert->data_len)) {
logit("Unable to parse X.509 certificate");
r = -1;
goto err;
}
sc_pkcs15_free_certificate(cert);
cert = NULL;
pubkey = X509_get_pubkey(x509);
X509_free(x509);
x509 = NULL;
if (pubkey->type != EVP_PKEY_RSA) {
logit("Public key is of unknown type");
r = -1;
goto err;
}
k->rsa = EVP_PKEY_get1_RSA(pubkey);
EVP_PKEY_free(pubkey);
k->rsa->flags |= RSA_FLAG_SIGN_VER;
RSA_set_method(k->rsa, sc_get_rsa_method());
priv = xmalloc(sizeof(struct sc_priv_data));
priv->cert_id = cinfo->id;
priv->ref_count = 1;
RSA_set_app_data(k->rsa, priv);
k->flags = KEY_FLAG_EXT;
tmp = key_fingerprint(k, SSH_FP_MD5, SSH_FP_HEX);
debug("fingerprint %d %s", key_size(k), tmp);
xfree(tmp);
return 0;
err:
if (cert)
sc_pkcs15_free_certificate(cert);
if (pubkey)
EVP_PKEY_free(pubkey);
if (x509)
X509_free(x509);
return r;
}
Key **
sc_get_keys(const char *id, const char *pin)
{
Key *k, **keys;
int i, r, real_count = 0, key_count;
sc_pkcs15_id_t cert_id;
sc_pkcs15_object_t *certs[32];
char *buf = xstrdup(id), *p;
debug("sc_get_keys called: id = %s", id);
if (sc_pin != NULL)
xfree(sc_pin);
sc_pin = (pin == NULL) ? NULL : xstrdup(pin);
cert_id.len = 0;
if ((p = strchr(buf, ':')) != NULL) {
*p = 0;
p++;
sc_pkcs15_hex_string_to_id(p, &cert_id);
}
r = sscanf(buf, "%d", &sc_reader_id);
xfree(buf);
if (r != 1)
goto err;
if (p15card == NULL) {
sc_close();
r = sc_init();
if (r) {
error("Smartcard init failed: %s", sc_strerror(r));
goto err;
}
}
if (cert_id.len) {
r = sc_pkcs15_find_cert_by_id(p15card, &cert_id, &certs[0]);
if (r < 0)
goto err;
key_count = 1;
} else {
r = sc_pkcs15_get_objects(p15card, SC_PKCS15_TYPE_CERT_X509,
certs, 32);
if (r == 0) {
logit("No certificates found on smartcard");
r = -1;
goto err;
} else if (r < 0) {
error("Certificate enumeration failed: %s",
sc_strerror(r));
goto err;
}
key_count = r;
}
if (key_count > 1024)
fatal("Too many keys (%u), expected <= 1024", key_count);
keys = xcalloc(key_count * 2 + 1, sizeof(Key *));
for (i = 0; i < key_count; i++) {
sc_pkcs15_object_t *tmp_obj = NULL;
cert_id = ((sc_pkcs15_cert_info_t *)(certs[i]->data))->id;
if (sc_pkcs15_find_prkey_by_id(p15card, &cert_id, &tmp_obj))
/* skip the public key (certificate) if no
* corresponding private key is present */
continue;
k = key_new(KEY_RSA);
if (k == NULL)
break;
r = sc_read_pubkey(k, certs[i]);
if (r) {
error("sc_read_pubkey failed: %s", sc_strerror(r));
key_free(k);
continue;
}
keys[real_count] = k;
real_count++;
k = key_new(KEY_RSA1);
if (k == NULL)
break;
convert_rsa_to_rsa1(keys[real_count-1], k);
keys[real_count] = k;
real_count++;
}
keys[real_count] = NULL;
return keys;
err:
sc_close();
return NULL;
}
int
sc_put_key(Key *prv, const char *id)
{
error("key uploading not yet supported");
return -1;
}
char *
sc_get_key_label(Key *key)
{
int r;
const struct sc_priv_data *priv;
struct sc_pkcs15_object *key_obj;
priv = (const struct sc_priv_data *) RSA_get_app_data(key->rsa);
if (priv == NULL || p15card == NULL) {
logit("SmartCard key not loaded");
/* internal error => return default label */
return xstrdup("smartcard key");
}
r = sc_pkcs15_find_prkey_by_id(p15card, &priv->cert_id, &key_obj);
if (r) {
logit("Unable to find private key from SmartCard: %s",
sc_strerror(r));
return xstrdup("smartcard key");
}
if (key_obj == NULL || key_obj->label == NULL)
/* the optional PKCS#15 label does not exists
* => return the default label */
return xstrdup("smartcard key");
return xstrdup(key_obj->label);
}
#endif /* SMARTCARD */