~ubuntu-branches/ubuntu/lucid/openssh/lucid

/*

 * 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 <string.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 */