Moved TLS stack to its own library

2010-08-03 15:39:26 +02:00
parent 0b71bc7af0
commit 0f82a47063
28 changed files with 65 additions and 42 deletions
@@ -0,0 +1,625 @@
+/*
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * This program 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 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program 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.
+ */
+
+#include "tls_peer.h"
+
+#include <debug.h>
+
+#include <time.h>
+
+typedef struct private_tls_peer_t private_tls_peer_t;
+
+typedef enum {
+	STATE_INIT,
+	STATE_HELLO_SENT,
+	STATE_HELLO_RECEIVED,
+	STATE_HELLO_DONE,
+	STATE_CERT_SENT,
+	STATE_CERT_RECEIVED,
+	STATE_CERTREQ_RECEIVED,
+	STATE_KEY_EXCHANGE_SENT,
+	STATE_VERIFY_SENT,
+	STATE_CIPHERSPEC_CHANGED_OUT,
+	STATE_FINISHED_SENT,
+	STATE_CIPHERSPEC_CHANGED_IN,
+	STATE_COMPLETE,
+} peer_state_t;
+
+/**
+ * Private data of an tls_peer_t object.
+ */
+struct private_tls_peer_t {
+
+	/**
+	 * Public tls_peer_t interface.
+	 */
+	tls_peer_t public;
+
+	/**
+	 * TLS stack
+	 */
+	tls_t *tls;
+
+	/**
+	 * TLS crypto context
+	 */
+	tls_crypto_t *crypto;
+
+	/**
+	 * Peer identity
+	 */
+	identification_t *peer;
+
+	/**
+	 * Server identity
+	 */
+	identification_t *server;
+
+	/**
+	 * State we are in
+	 */
+	peer_state_t state;
+
+	/**
+	 * Hello random data selected by client
+	 */
+	char client_random[32];
+
+	/**
+	 * Hello random data selected by server
+	 */
+	char server_random[32];
+
+	/**
+	 * Auth helper for peer authentication
+	 */
+	auth_cfg_t *peer_auth;
+
+	/**
+	 * Auth helper for server authentication
+	 */
+	auth_cfg_t *server_auth;
+
+	/**
+	 * Peer private key
+	 */
+	private_key_t *private;
+};
+
+/**
+ * Process a server hello message
+ */
+static status_t process_server_hello(private_tls_peer_t *this,
+									 tls_reader_t *reader)
+{
+	u_int8_t compression;
+	u_int16_t version, cipher;
+	chunk_t random, session, ext = chunk_empty;
+	tls_cipher_suite_t suite;
+
+	this->crypto->append_handshake(this->crypto,
+								   TLS_SERVER_HELLO, reader->peek(reader));
+
+	if (!reader->read_uint16(reader, &version) ||
+		!reader->read_data(reader, sizeof(this->server_random), &random) ||
+		!reader->read_data8(reader, &session) ||
+		!reader->read_uint16(reader, &cipher) ||
+		!reader->read_uint8(reader, &compression) ||
+		(reader->remaining(reader) && !reader->read_data16(reader, &ext)))
+	{
+		DBG1(DBG_IKE, "received invalid ServerHello");
+		return FAILED;
+	}
+
+	memcpy(this->server_random, random.ptr, sizeof(this->server_random));
+
+	if (version < this->tls->get_version(this->tls))
+	{
+		this->tls->set_version(this->tls, version);
+	}
+	suite = cipher;
+	if (!this->crypto->select_cipher_suite(this->crypto, &suite, 1))
+	{
+		DBG1(DBG_IKE, "received cipher suite inacceptable");
+		return FAILED;
+	}
+	this->state = STATE_HELLO_RECEIVED;
+	return NEED_MORE;
+}
+
+/**
+ * Process a Certificate message
+ */
+static status_t process_certificate(private_tls_peer_t *this,
+									tls_reader_t *reader)
+{
+	certificate_t *cert;
+	tls_reader_t *certs;
+	chunk_t data;
+	bool first = TRUE;
+
+	this->crypto->append_handshake(this->crypto,
+								   TLS_CERTIFICATE, reader->peek(reader));
+
+	if (!reader->read_data24(reader, &data))
+	{
+		return FAILED;
+	}
+	certs = tls_reader_create(data);
+	while (certs->remaining(certs))
+	{
+		if (!certs->read_data24(certs, &data))
+		{
+			certs->destroy(certs);
+			return FAILED;
+		}
+		cert = lib->creds->create(lib->creds, CRED_CERTIFICATE, CERT_X509,
+								  BUILD_BLOB_ASN1_DER, data, BUILD_END);
+		if (cert)
+		{
+			if (first)
+			{
+				this->server_auth->add(this->server_auth,
+									   AUTH_HELPER_SUBJECT_CERT, cert);
+				DBG1(DBG_IKE, "received TLS server certificate '%Y'",
+					 cert->get_subject(cert));
+				first = FALSE;
+			}
+			else
+			{
+				DBG1(DBG_IKE, "received TLS intermediate certificate '%Y'",
+					 cert->get_subject(cert));
+				this->server_auth->add(this->server_auth,
+									   AUTH_HELPER_IM_CERT, cert);
+			}
+		}
+		else
+		{
+			DBG1(DBG_IKE, "parsing TLS certificate failed, skipped");
+		}
+	}
+	certs->destroy(certs);
+	this->state = STATE_CERT_RECEIVED;
+	return NEED_MORE;
+}
+
+/**
+ * Process a Certificate message
+ */
+static status_t process_certreq(private_tls_peer_t *this, tls_reader_t *reader)
+{
+	chunk_t types, hashsig, data;
+	tls_reader_t *authorities;
+	identification_t *id;
+	certificate_t *cert;
+
+	this->crypto->append_handshake(this->crypto,
+								TLS_CERTIFICATE_REQUEST, reader->peek(reader));
+
+	if (!reader->read_data8(reader, &types))
+	{
+		return FAILED;
+	}
+	if (this->tls->get_version(this->tls) >= TLS_1_2)
+	{
+		if (!reader->read_data16(reader, &hashsig))
+		{
+			return FAILED;
+		}
+		/* TODO: store supported hashsig algorithms */
+	}
+	if (!reader->read_data16(reader, &data))
+	{
+		return FAILED;
+	}
+	authorities = tls_reader_create(data);
+	while (authorities->remaining(authorities))
+	{
+		if (!authorities->read_data16(authorities, &data))
+		{
+			authorities->destroy(authorities);
+			return FAILED;
+		}
+		id = identification_create_from_encoding(ID_DER_ASN1_DN, data);
+		cert = lib->credmgr->get_cert(lib->credmgr,
+									  CERT_X509, KEY_ANY, id, TRUE);
+		if (cert)
+		{
+			DBG1(DBG_IKE, "received cert request for '%Y", id);
+			this->peer_auth->add(this->peer_auth, AUTH_RULE_CA_CERT, cert);
+		}
+		else
+		{
+			DBG1(DBG_IKE, "received cert request for unknown CA '%Y'", id);
+		}
+		id->destroy(id);
+	}
+	authorities->destroy(authorities);
+	this->state = STATE_CERTREQ_RECEIVED;
+	return NEED_MORE;
+}
+
+/**
+ * Process Hello Done message
+ */
+static status_t process_hello_done(private_tls_peer_t *this,
+								   tls_reader_t *reader)
+{
+	this->crypto->append_handshake(this->crypto,
+								   TLS_SERVER_HELLO_DONE, reader->peek(reader));
+	this->state = STATE_HELLO_DONE;
+	return NEED_MORE;
+}
+
+/**
+ * Process finished message
+ */
+static status_t process_finished(private_tls_peer_t *this, tls_reader_t *reader)
+{
+	chunk_t received;
+	char buf[12];
+
+	if (!reader->read_data(reader, sizeof(buf), &received))
+	{
+		DBG1(DBG_IKE, "received server finished too short");
+		return FAILED;
+	}
+	if (!this->crypto->calculate_finished(this->crypto, "server finished", buf))
+	{
+		DBG1(DBG_IKE, "calculating server finished failed");
+		return FAILED;
+	}
+	if (!chunk_equals(received, chunk_from_thing(buf)))
+	{
+		DBG1(DBG_IKE, "received server finished invalid");
+		return FAILED;
+	}
+	this->state = STATE_COMPLETE;
+	this->crypto->derive_eap_msk(this->crypto,
+								 chunk_from_thing(this->client_random),
+								 chunk_from_thing(this->server_random));
+	return NEED_MORE;
+}
+
+METHOD(tls_handshake_t, process, status_t,
+	private_tls_peer_t *this, tls_handshake_type_t type, tls_reader_t *reader)
+{
+	tls_handshake_type_t expected;
+
+	switch (this->state)
+	{
+		case STATE_HELLO_SENT:
+			if (type == TLS_SERVER_HELLO)
+			{
+				return process_server_hello(this, reader);
+			}
+			expected = TLS_SERVER_HELLO;
+			break;
+		case STATE_HELLO_RECEIVED:
+			if (type == TLS_CERTIFICATE)
+			{
+				return process_certificate(this, reader);
+			}
+			expected = TLS_CERTIFICATE;
+			break;
+		case STATE_CERT_RECEIVED:
+			if (type == TLS_CERTIFICATE_REQUEST)
+			{
+				return process_certreq(this, reader);
+			}
+			expected = TLS_CERTIFICATE_REQUEST;
+			break;
+		case STATE_CERTREQ_RECEIVED:
+			if (type == TLS_SERVER_HELLO_DONE)
+			{
+				return process_hello_done(this, reader);
+			}
+			expected = TLS_SERVER_HELLO_DONE;
+			break;
+		case STATE_CIPHERSPEC_CHANGED_IN:
+			if (type == TLS_FINISHED)
+			{
+				return process_finished(this, reader);
+			}
+			expected = TLS_FINISHED;
+			break;
+		default:
+			DBG1(DBG_IKE, "TLS %N not expected in current state",
+				 tls_handshake_type_names, type);
+			return FAILED;
+	}
+	DBG1(DBG_IKE, "TLS %N expected, but received %N",
+		 tls_handshake_type_names, expected, tls_handshake_type_names, type);
+	return FAILED;
+}
+
+/**
+ * Send a client hello
+ */
+static status_t send_client_hello(private_tls_peer_t *this,
+							tls_handshake_type_t *type, tls_writer_t *writer)
+{
+	tls_cipher_suite_t *suite;
+	int count, i;
+	rng_t *rng;
+
+	htoun32(&this->client_random, time(NULL));
+	rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
+	if (!rng)
+	{
+		return FAILED;
+	}
+	rng->get_bytes(rng, sizeof(this->client_random) - 4, this->client_random + 4);
+	rng->destroy(rng);
+
+	writer->write_uint16(writer, this->tls->get_version(this->tls));
+	writer->write_data(writer, chunk_from_thing(this->client_random));
+	/* session identifier => none */
+	writer->write_data8(writer, chunk_empty);
+
+	count = this->crypto->get_cipher_suites(this->crypto, &suite);
+	writer->write_uint16(writer, count * 2);
+	for (i = 0; i < count; i++)
+	{
+		writer->write_uint16(writer, suite[i]);
+	}
+	/* NULL compression only */
+	writer->write_uint8(writer, 1);
+	writer->write_uint8(writer, 0);
+
+	*type = TLS_CLIENT_HELLO;
+	this->state = STATE_HELLO_SENT;
+	this->crypto->append_handshake(this->crypto, *type, writer->get_buf(writer));
+	return NEED_MORE;
+}
+
+/**
+ * Send Certificate
+ */
+static status_t send_certificate(private_tls_peer_t *this,
+							tls_handshake_type_t *type, tls_writer_t *writer)
+{
+	enumerator_t *enumerator;
+	certificate_t *cert;
+	auth_rule_t rule;
+	tls_writer_t *certs;
+	chunk_t data;
+
+	this->private = lib->credmgr->get_private(lib->credmgr,
+										KEY_ANY, this->peer, this->peer_auth);
+	if (!this->private)
+	{
+		DBG1(DBG_IKE, "no TLS peer certificate found for '%Y'", this->peer);
+		return FAILED;
+	}
+
+	/* generate certificate payload */
+	certs = tls_writer_create(256);
+	cert = this->peer_auth->get(this->peer_auth, AUTH_RULE_SUBJECT_CERT);
+	if (cert)
+	{
+		if (cert->get_encoding(cert, CERT_ASN1_DER, &data))
+		{
+			DBG1(DBG_IKE, "sending TLS peer certificate '%Y'",
+				 cert->get_subject(cert));
+			certs->write_data24(certs, data);
+			free(data.ptr);
+		}
+	}
+	enumerator = this->peer_auth->create_enumerator(this->peer_auth);
+	while (enumerator->enumerate(enumerator, &rule, &cert))
+	{
+		if (rule == AUTH_RULE_IM_CERT)
+		{
+			if (cert->get_encoding(cert, CERT_ASN1_DER, &data))
+			{
+				DBG1(DBG_IKE, "sending TLS intermediate certificate '%Y'",
+					 cert->get_subject(cert));
+				certs->write_data24(certs, data);
+				free(data.ptr);
+			}
+		}
+	}
+	enumerator->destroy(enumerator);
+
+	writer->write_data24(writer, certs->get_buf(certs));
+	certs->destroy(certs);
+
+	*type = TLS_CERTIFICATE;
+	this->state = STATE_CERT_SENT;
+	this->crypto->append_handshake(this->crypto, *type, writer->get_buf(writer));
+	return NEED_MORE;
+}
+
+/**
+ * Send client key exchange
+ */
+static status_t send_key_exchange(private_tls_peer_t *this,
+							tls_handshake_type_t *type, tls_writer_t *writer)
+{
+	public_key_t *public = NULL, *current;
+	enumerator_t *enumerator;
+	auth_cfg_t *auth;
+	rng_t *rng;
+	char premaster[48];
+	chunk_t encrypted;
+
+	rng = lib->crypto->create_rng(lib->crypto, RNG_STRONG);
+	if (!rng)
+	{
+		DBG1(DBG_IKE, "no suitable RNG found for TLS premaster secret");
+		return FAILED;
+	}
+	rng->get_bytes(rng, sizeof(premaster) - 2, premaster + 2);
+	rng->destroy(rng);
+	htoun16(premaster, TLS_1_2);
+
+	this->crypto->derive_secrets(this->crypto, chunk_from_thing(premaster),
+								 chunk_from_thing(this->client_random),
+								 chunk_from_thing(this->server_random));
+
+	enumerator = lib->credmgr->create_public_enumerator(lib->credmgr,
+									KEY_ANY, this->server, this->server_auth);
+	while (enumerator->enumerate(enumerator, &current, &auth))
+	{
+		public = current->get_ref(current);
+		break;
+	}
+	enumerator->destroy(enumerator);
+
+	if (!public)
+	{
+		DBG1(DBG_IKE, "no TLS public key found for server '%Y'", this->server);
+		return FAILED;
+	}
+	if (!public->encrypt(public, chunk_from_thing(premaster), &encrypted))
+	{
+		public->destroy(public);
+		DBG1(DBG_IKE, "encrypting TLS premaster secret failed");
+		return FAILED;
+	}
+
+	public->destroy(public);
+
+	writer->write_data16(writer, encrypted);
+	free(encrypted.ptr);
+
+	*type = TLS_CLIENT_KEY_EXCHANGE;
+	this->state = STATE_KEY_EXCHANGE_SENT;
+	this->crypto->append_handshake(this->crypto, *type, writer->get_buf(writer));
+	return NEED_MORE;
+}
+
+/**
+ * Send certificate verify
+ */
+static status_t send_certificate_verify(private_tls_peer_t *this,
+							tls_handshake_type_t *type, tls_writer_t *writer)
+{
+	if (!this->private ||
+		!this->crypto->sign_handshake(this->crypto, this->private, writer))
+	{
+		DBG1(DBG_IKE, "creating TLS Certificate Verify signature failed");
+		return FAILED;
+	}
+
+	*type = TLS_CERTIFICATE_VERIFY;
+	this->state = STATE_VERIFY_SENT;
+	this->crypto->append_handshake(this->crypto, *type, writer->get_buf(writer));
+	return NEED_MORE;
+}
+
+/**
+ * Send Finished
+ */
+static status_t send_finished(private_tls_peer_t *this,
+							  tls_handshake_type_t *type, tls_writer_t *writer)
+{
+	char buf[12];
+
+	if (!this->crypto->calculate_finished(this->crypto, "client finished", buf))
+	{
+		DBG1(DBG_IKE, "calculating client finished data failed");
+		return FAILED;
+	}
+
+	writer->write_data(writer, chunk_from_thing(buf));
+
+	*type = TLS_FINISHED;
+	this->state = STATE_FINISHED_SENT;
+	this->crypto->append_handshake(this->crypto, *type, writer->get_buf(writer));
+	return NEED_MORE;
+}
+
+METHOD(tls_handshake_t, build, status_t,
+	private_tls_peer_t *this, tls_handshake_type_t *type, tls_writer_t *writer)
+{
+	switch (this->state)
+	{
+		case STATE_INIT:
+			return send_client_hello(this, type, writer);
+		case STATE_HELLO_DONE:
+			return send_certificate(this, type, writer);
+		case STATE_CERT_SENT:
+			return send_key_exchange(this, type, writer);
+		case STATE_KEY_EXCHANGE_SENT:
+			return send_certificate_verify(this, type, writer);
+		case STATE_CIPHERSPEC_CHANGED_OUT:
+			return send_finished(this, type, writer);
+		default:
+			return INVALID_STATE;
+	}
+}
+
+METHOD(tls_handshake_t, cipherspec_changed, bool,
+	private_tls_peer_t *this)
+{
+	if (this->state == STATE_VERIFY_SENT)
+	{
+		this->crypto->change_cipher(this->crypto, FALSE);
+		this->state = STATE_CIPHERSPEC_CHANGED_OUT;
+		return TRUE;
+	}
+	return FALSE;
+}
+
+METHOD(tls_handshake_t, change_cipherspec, bool,
+	private_tls_peer_t *this)
+{
+	if (this->state == STATE_FINISHED_SENT)
+	{
+		this->crypto->change_cipher(this->crypto, TRUE);
+		this->state = STATE_CIPHERSPEC_CHANGED_IN;
+		return TRUE;
+	}
+	return FALSE;
+}
+
+METHOD(tls_handshake_t, destroy, void,
+	private_tls_peer_t *this)
+{
+	DESTROY_IF(this->private);
+	this->peer_auth->destroy(this->peer_auth);
+	this->server_auth->destroy(this->server_auth);
+	free(this);
+}
+
+/**
+ * See header
+ */
+tls_peer_t *tls_peer_create(tls_t *tls, tls_crypto_t *crypto,
+							identification_t *peer, identification_t *server)
+{
+	private_tls_peer_t *this;
+
+	INIT(this,
+		.public.handshake = {
+			.process = _process,
+			.build = _build,
+			.cipherspec_changed = _cipherspec_changed,
+			.change_cipherspec = _change_cipherspec,
+			.destroy = _destroy,
+		},
+		.state = STATE_INIT,
+		.tls = tls,
+		.crypto = crypto,
+		.peer = peer,
+		.server = server,
+		.peer_auth = auth_cfg_create(),
+		.server_auth = auth_cfg_create(),
+	);
+
+	return &this->public;
+}