- (bal) Patch for OpenSC SmartCard library; ok markus@; patch by

   Juha Yrjölä <jyrjola@cc.hut.fi>
 - (bal) Minor documentation update to reflect smartcard library
   support changes.

1 files changed, 462 insertions, 0 deletions

diff --git a/scard-opensc.c b/scard-opensc.c
new file mode 100644
index 00000000..2a18bebd
--- /dev/null
+++ b/scard-opensc.c
@@ -0,0 +1,462 @@
+/*
+ * 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 <openssl/evp.h>
+#include <openssl/x509.h>
+
+#include <opensc.h>
+#include <opensc-pkcs15.h>
+
+#include "key.h"
+#include "log.h"
+#include "xmalloc.h"
+#include "readpass.h"
+#include "scard.h"
+
+#if OPENSSL_VERSION_NUMBER >= 0x00907000L
+#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;
+	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)
+{
+	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(p15card, &priv->cert_id, &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) {
+		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;
+}
+
+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);
+	if (r)
+		return -1;
+	r = sc_pkcs15_decipher(p15card, key_obj, 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;
+}
+
+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;
+
+	r = sc_prkey_op_init(rsa, &key_obj);
+	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) {
+		log("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)) {
+		log("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) {
+		log("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) {
+			log("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;
+	}
+	/* FIXME: only keep entries with a corresponding private key */
+	keys = xmalloc(sizeof(Key *) * (key_count*2+1));
+	for (i = 0; i < key_count; i++) {
+		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;
+}
+
+#endif /* SMARTCARD */