1 files changed, 691 insertions, 0 deletions

diff --git a/src/libtls/tls_crypto.c b/src/libtls/tls_crypto.c
new file mode 100644
index 000000000..085c11e2d
--- /dev/null
+++ b/src/libtls/tls_crypto.c
@@ -0,0 +1,691 @@
+/*
+ * 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_crypto.h"
+
+#include <debug.h>
+
+typedef struct private_tls_crypto_t private_tls_crypto_t;
+
+/**
+ * Private data of an tls_crypto_t object.
+ */
+struct private_tls_crypto_t {
+
+	/**
+	 * Public tls_crypto_t interface.
+	 */
+	tls_crypto_t public;
+
+	/**
+	 * Protection layer
+	 */
+	tls_protection_t *protection;
+
+	/**
+	 * List of supported/acceptable cipher suites
+	 */
+	tls_cipher_suite_t *suites;
+
+	/**
+	 * Number of supported suites
+	 */
+	int suite_count;
+
+	/**
+	 * Selected cipher suite
+	 */
+	tls_cipher_suite_t suite;
+
+	/**
+	 * TLS context
+	 */
+	tls_t *tls;
+
+	/**
+	 * All handshake data concatentated
+	 */
+	chunk_t handshake;
+
+	/**
+	 * Connection state TLS PRF
+	 */
+	tls_prf_t *prf;
+
+	/**
+	 * Signer instance for inbound traffic
+	 */
+	signer_t *signer_in;
+
+	/**
+	 * Signer instance for outbound traffic
+	 */
+	signer_t *signer_out;
+
+	/**
+	 * Crypter instance for inbound traffic
+	 */
+	crypter_t *crypter_in;
+
+	/**
+	 * Crypter instance for outbound traffic
+	 */
+	crypter_t *crypter_out;
+
+	/**
+	 * IV for input decryption, if < TLSv1.2
+	 */
+	chunk_t iv_in;
+
+	/**
+	 * IV for output decryption, if < TLSv1.2
+	 */
+	chunk_t iv_out;
+
+	/**
+	 * EAP-TLS MSK
+	 */
+	chunk_t msk;
+};
+
+typedef struct {
+	tls_cipher_suite_t suite;
+	hash_algorithm_t hash;
+	pseudo_random_function_t prf;
+	integrity_algorithm_t mac;
+	encryption_algorithm_t encr;
+	size_t encr_size;
+} suite_algs_t;
+
+/**
+ * Mapping suites to a set of algorithms
+ */
+static suite_algs_t suite_algs[] = {
+	{ TLS_RSA_WITH_NULL_MD5,
+		HASH_MD5,
+		PRF_HMAC_MD5,
+		AUTH_HMAC_MD5_128,
+		ENCR_NULL, 0
+	},
+	{ TLS_RSA_WITH_NULL_SHA,
+		HASH_SHA1,
+		PRF_HMAC_SHA1,
+		AUTH_HMAC_SHA1_160,
+		ENCR_NULL, 0
+	},
+	{ TLS_RSA_WITH_NULL_SHA256,
+		HASH_SHA256,
+		PRF_HMAC_SHA2_256,
+		AUTH_HMAC_SHA2_256_256,
+		ENCR_NULL, 0
+	},
+	{ TLS_RSA_WITH_AES_128_CBC_SHA,
+		HASH_SHA1,
+		PRF_HMAC_SHA1,
+		AUTH_HMAC_SHA1_160,
+		ENCR_AES_CBC, 16
+	},
+	{ TLS_RSA_WITH_AES_256_CBC_SHA,
+		HASH_SHA1,
+		PRF_HMAC_SHA1,
+		AUTH_HMAC_SHA1_160,
+		ENCR_AES_CBC, 32
+	},
+	{ TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+		HASH_SHA1,
+		PRF_HMAC_SHA1,
+		AUTH_HMAC_SHA1_160,
+		ENCR_3DES, 0
+	},
+	{ TLS_RSA_WITH_AES_128_CBC_SHA256,
+		HASH_SHA256,
+		PRF_HMAC_SHA2_256,
+		AUTH_HMAC_SHA2_256_256,
+		ENCR_AES_CBC, 16
+	},
+};
+
+/**
+ * Look up algoritms by a suite
+ */
+static suite_algs_t *find_suite(tls_cipher_suite_t suite)
+{
+	int i;
+
+	for (i = 0; i < countof(suite_algs); i++)
+	{
+		if (suite_algs[i].suite == suite)
+		{
+			return &suite_algs[i];
+		}
+	}
+	return NULL;
+}
+
+/**
+ * Initialize the cipher suite list
+ */
+static void build_cipher_suite_list(private_tls_crypto_t *this)
+{
+	encryption_algorithm_t encr;
+	integrity_algorithm_t mac;
+	enumerator_t *encrs, *macs;
+	tls_cipher_suite_t supported[64], unique[64];
+	int count = 0, i, j;
+
+	/* we assume that we support RSA, but no DHE yet */
+	macs = lib->crypto->create_signer_enumerator(lib->crypto);
+	while (macs->enumerate(macs, &mac))
+	{
+		switch (mac)
+		{
+			case AUTH_HMAC_SHA1_160:
+				supported[count++] = TLS_RSA_WITH_NULL_SHA;
+				break;
+			case AUTH_HMAC_SHA2_256_256:
+				supported[count++] = TLS_RSA_WITH_NULL_SHA256;
+				break;
+			case AUTH_HMAC_MD5_128:
+				supported[count++] = TLS_RSA_WITH_NULL_MD5;
+				break;
+			default:
+				break;
+		}
+		encrs = lib->crypto->create_crypter_enumerator(lib->crypto);
+		while (encrs->enumerate(encrs, &encr))
+		{
+			switch (encr)
+			{
+				case ENCR_AES_CBC:
+					switch (mac)
+					{
+						case AUTH_HMAC_SHA1_160:
+							supported[count++] = TLS_RSA_WITH_AES_128_CBC_SHA;
+							supported[count++] = TLS_RSA_WITH_AES_256_CBC_SHA;
+							break;
+						case AUTH_HMAC_SHA2_256_256:
+							supported[count++] = TLS_RSA_WITH_AES_128_CBC_SHA256;
+							supported[count++] = TLS_RSA_WITH_AES_128_CBC_SHA256;
+							break;
+						default:
+							break;
+					}
+					break;
+				case ENCR_3DES:
+					switch (mac)
+					{
+						case AUTH_HMAC_SHA1_160:
+							supported[count++] = TLS_RSA_WITH_3DES_EDE_CBC_SHA;
+							break;
+						default:
+							break;
+					}
+					break;
+				default:
+					break;
+			}
+		}
+		encrs->destroy(encrs);
+	}
+	macs->destroy(macs);
+
+	/* remove duplicates */
+	this->suite_count = 0;
+	for (i = 0; i < count; i++)
+	{
+		bool match = FALSE;
+
+		for (j = 0; j < this->suite_count; j++)
+		{
+			if (supported[i] == unique[j])
+			{
+				match = TRUE;
+				break;
+			}
+		}
+		if (!match)
+		{
+			unique[this->suite_count++] = supported[i];
+		}
+	}
+	free(this->suites);
+	this->suites = malloc(sizeof(tls_cipher_suite_t) * this->suite_count);
+	memcpy(this->suites, unique, sizeof(tls_cipher_suite_t) * this->suite_count);
+}
+
+METHOD(tls_crypto_t, get_cipher_suites, int,
+	private_tls_crypto_t *this, tls_cipher_suite_t **suites)
+{
+	*suites = this->suites;
+	return this->suite_count;
+}
+
+/**
+ * Create crypto primitives
+ */
+static bool create_ciphers(private_tls_crypto_t *this, tls_cipher_suite_t suite)
+{
+	suite_algs_t *algs;
+
+	algs = find_suite(suite);
+	if (!algs)
+	{
+		DBG1(DBG_IKE, "selected TLS suite not supported");
+		return FALSE;
+	}
+
+	DESTROY_IF(this->prf);
+	if (this->tls->get_version(this->tls) < TLS_1_2)
+	{
+		this->prf = tls_prf_create_10();
+	}
+	else
+	{
+		this->prf = tls_prf_create_12(algs->prf);
+	}
+	if (!this->prf)
+	{
+		DBG1(DBG_IKE, "selected TLS PRF not supported");
+		return FALSE;
+	}
+
+	DESTROY_IF(this->signer_in);
+	DESTROY_IF(this->signer_out);
+	this->signer_in = lib->crypto->create_signer(lib->crypto, algs->mac);
+	this->signer_out = lib->crypto->create_signer(lib->crypto, algs->mac);
+	if (!this->signer_in || !this->signer_out)
+	{
+		DBG1(DBG_IKE, "selected TLS MAC %N not supported",
+			 integrity_algorithm_names, algs->mac);
+		return FALSE;
+	}
+
+	DESTROY_IF(this->crypter_in);
+	DESTROY_IF(this->crypter_out);
+	if (algs->encr == ENCR_NULL)
+	{
+		this->crypter_in = this->crypter_out = NULL;
+	}
+	else
+	{
+		this->crypter_in = lib->crypto->create_crypter(lib->crypto,
+												algs->encr, algs->encr_size);
+		this->crypter_out = lib->crypto->create_crypter(lib->crypto,
+												algs->encr, algs->encr_size);
+		if (!this->crypter_in || !this->crypter_out)
+		{
+			DBG1(DBG_IKE, "selected TLS crypter %N not supported",
+				 encryption_algorithm_names, algs->encr);
+			return FALSE;
+		}
+	}
+	return TRUE;
+}
+
+METHOD(tls_crypto_t, select_cipher_suite, tls_cipher_suite_t,
+	private_tls_crypto_t *this, tls_cipher_suite_t *suites, int count)
+{
+	int i, j;
+
+	for (i = 0; i < this->suite_count; i++)
+	{
+		for (j = 0; j < count; j++)
+		{
+			if (this->suites[i] == suites[j])
+			{
+				if (create_ciphers(this, this->suites[i]))
+				{
+					this->suite = this->suites[i];
+					return this->suite;
+				}
+			}
+		}
+	}
+	return 0;
+}
+
+METHOD(tls_crypto_t, set_protection, void,
+	private_tls_crypto_t *this, tls_protection_t *protection)
+{
+	this->protection = protection;
+}
+
+METHOD(tls_crypto_t, append_handshake, void,
+	private_tls_crypto_t *this, tls_handshake_type_t type, chunk_t data)
+{
+	u_int32_t header;
+
+	/* reconstruct handshake header */
+	header = htonl(data.len | (type << 24));
+	this->handshake = chunk_cat("mcc", this->handshake,
+								chunk_from_thing(header), data);
+}
+
+/**
+ * Create a hash of the stored handshake data
+ */
+static bool hash_handshake(private_tls_crypto_t *this, chunk_t *hash)
+{
+	if (this->tls->get_version(this->tls) >= TLS_1_2)
+	{
+		hasher_t *hasher;
+		suite_algs_t *alg;
+
+		alg = find_suite(this->suite);
+		if (!alg)
+		{
+			return FALSE;
+		}
+		hasher = lib->crypto->create_hasher(lib->crypto, alg->hash);
+		if (!hasher)
+		{
+			DBG1(DBG_IKE, "%N not supported", hash_algorithm_names, alg->hash);
+			return FALSE;
+		}
+		hasher->allocate_hash(hasher, this->handshake, hash);
+		hasher->destroy(hasher);
+	}
+	else
+	{
+		hasher_t *md5, *sha1;
+		char buf[HASH_SIZE_MD5 + HASH_SIZE_SHA1];
+
+		md5 = lib->crypto->create_hasher(lib->crypto, HASH_MD5);
+		if (!md5)
+		{
+			DBG1(DBG_IKE, "%N not supported", hash_algorithm_names, HASH_MD5);
+			return FALSE;
+		}
+		md5->get_hash(md5, this->handshake, buf);
+		md5->destroy(md5);
+		sha1 = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
+		if (!sha1)
+		{
+			DBG1(DBG_IKE, "%N not supported", hash_algorithm_names, HASH_SHA1);
+			return FALSE;
+		}
+		sha1->get_hash(sha1, this->handshake, buf + HASH_SIZE_MD5);
+		sha1->destroy(sha1);
+
+		*hash = chunk_clone(chunk_from_thing(buf));
+	}
+	return TRUE;
+}
+
+METHOD(tls_crypto_t, sign_handshake, bool,
+	private_tls_crypto_t *this, private_key_t *key, tls_writer_t *writer)
+{
+	chunk_t sig, hash;
+
+	if (this->tls->get_version(this->tls) >= TLS_1_2)
+	{
+		/* TODO: use supported algorithms instead of fixed SHA1/RSA */
+		if (!key->sign(key, SIGN_RSA_EMSA_PKCS1_SHA1, this->handshake, &sig))
+		{
+			return FALSE;
+		}
+		writer->write_uint8(writer, 2);
+		writer->write_uint8(writer, 1);
+		writer->write_data16(writer, sig);
+		free(sig.ptr);
+	}
+	else
+	{
+		if (!hash_handshake(this, &hash))
+		{
+			return FALSE;
+		}
+		if (!key->sign(key, SIGN_RSA_EMSA_PKCS1_NULL, hash, &sig))
+		{
+			free(hash.ptr);
+			return FALSE;
+		}
+		writer->write_data16(writer, sig);
+		free(hash.ptr);
+		free(sig.ptr);
+	}
+	return TRUE;
+}
+
+METHOD(tls_crypto_t, verify_handshake, bool,
+	private_tls_crypto_t *this, public_key_t *key, tls_reader_t *reader)
+{
+	if (this->tls->get_version(this->tls) >= TLS_1_2)
+	{
+		u_int8_t hash, alg;
+		chunk_t sig;
+
+		if (!reader->read_uint8(reader, &hash) ||
+			!reader->read_uint8(reader, &alg) ||
+			!reader->read_data16(reader, &sig))
+		{
+			DBG1(DBG_IKE, "received invalid Certificate Verify");
+			return FALSE;
+		}
+		/* TODO: map received hash/sig alg to signature scheme */
+		if (hash != 2 || alg != 1 ||
+			!key->verify(key, SIGN_RSA_EMSA_PKCS1_SHA1, this->handshake, sig))
+		{
+			return FALSE;
+		}
+	}
+	else
+	{
+		chunk_t sig, hash;
+
+		if (!reader->read_data16(reader, &sig))
+		{
+			DBG1(DBG_IKE, "received invalid Certificate Verify");
+			return FALSE;
+		}
+		if (!hash_handshake(this, &hash))
+		{
+			return FALSE;
+		}
+		if (!key->verify(key, SIGN_RSA_EMSA_PKCS1_NULL, hash, sig))
+		{
+			free(hash.ptr);
+			return FALSE;
+		}
+		free(hash.ptr);
+	}
+	return TRUE;
+}
+
+METHOD(tls_crypto_t, calculate_finished, bool,
+	private_tls_crypto_t *this, char *label, char out[12])
+{
+	chunk_t seed;
+
+	if (!this->prf)
+	{
+		return FALSE;
+	}
+	if (!hash_handshake(this, &seed))
+	{
+		return FALSE;
+	}
+	this->prf->get_bytes(this->prf, label, seed, 12, out);
+	free(seed.ptr);
+	return TRUE;
+}
+
+METHOD(tls_crypto_t, derive_secrets, void,
+	private_tls_crypto_t *this, chunk_t premaster,
+	chunk_t client_random, chunk_t server_random)
+{
+	char master[48];
+	chunk_t seed, block, client_write, server_write;
+	int mks, eks = 0, ivs = 0;
+
+	/* derive master secret */
+	seed = chunk_cata("cc", client_random, server_random);
+	this->prf->set_key(this->prf, premaster);
+	this->prf->get_bytes(this->prf, "master secret", seed,
+						 sizeof(master), master);
+
+	this->prf->set_key(this->prf, chunk_from_thing(master));
+	memset(master, 0, sizeof(master));
+
+	/* derive key block for key expansion */
+	mks = this->signer_out->get_key_size(this->signer_out);
+	if (this->crypter_out)
+	{
+		eks = this->crypter_out->get_key_size(this->crypter_out);
+		if (this->tls->get_version(this->tls) < TLS_1_1)
+		{
+			ivs = this->crypter_out->get_block_size(this->crypter_out);
+		}
+	}
+	seed = chunk_cata("cc", server_random, client_random);
+	block = chunk_alloca((mks + eks + ivs) * 2);
+	this->prf->get_bytes(this->prf, "key expansion", seed, block.len, block.ptr);
+
+	/* signer keys */
+	client_write = chunk_create(block.ptr, mks);
+	block = chunk_skip(block, mks);
+	server_write = chunk_create(block.ptr, mks);
+	block = chunk_skip(block, mks);
+	if (this->tls->is_server(this->tls))
+	{
+		this->signer_in->set_key(this->signer_in, client_write);
+		this->signer_out->set_key(this->signer_out, server_write);
+	}
+	else
+	{
+		this->signer_out->set_key(this->signer_out, client_write);
+		this->signer_in->set_key(this->signer_in, server_write);
+	}
+
+	/* crypter keys, and IVs if < TLSv1.2 */
+	if (this->crypter_out && this->crypter_in)
+	{
+		client_write = chunk_create(block.ptr, eks);
+		block = chunk_skip(block, eks);
+		server_write = chunk_create(block.ptr, eks);
+		block = chunk_skip(block, eks);
+
+		if (this->tls->is_server(this->tls))
+		{
+			this->crypter_in->set_key(this->crypter_in, client_write);
+			this->crypter_out->set_key(this->crypter_out, server_write);
+		}
+		else
+		{
+			this->crypter_out->set_key(this->crypter_out, client_write);
+			this->crypter_in->set_key(this->crypter_in, server_write);
+		}
+		if (ivs)
+		{
+			client_write = chunk_create(block.ptr, ivs);
+			block = chunk_skip(block, ivs);
+			server_write = chunk_create(block.ptr, ivs);
+			block = chunk_skip(block, ivs);
+
+			if (this->tls->is_server(this->tls))
+			{
+				this->iv_in = chunk_clone(client_write);
+				this->iv_out = chunk_clone(server_write);
+			}
+			else
+			{
+				this->iv_out = chunk_clone(client_write);
+				this->iv_in = chunk_clone(server_write);
+			}
+		}
+	}
+}
+
+METHOD(tls_crypto_t, change_cipher, void,
+	private_tls_crypto_t *this, bool inbound)
+{
+	if (this->protection)
+	{
+		if (inbound)
+		{
+			this->protection->set_cipher(this->protection, TRUE,
+							this->signer_in, this->crypter_in, this->iv_in);
+		}
+		else
+		{
+			this->protection->set_cipher(this->protection, FALSE,
+							this->signer_out, this->crypter_out, this->iv_out);
+		}
+	}
+}
+
+METHOD(tls_crypto_t, derive_eap_msk, void,
+	private_tls_crypto_t *this, chunk_t client_random, chunk_t server_random)
+{
+	chunk_t seed;
+
+	seed = chunk_cata("cc", client_random, server_random);
+	free(this->msk.ptr);
+	this->msk = chunk_alloc(64);
+	this->prf->get_bytes(this->prf, "client EAP encryption", seed,
+						 this->msk.len, this->msk.ptr);
+}
+
+METHOD(tls_crypto_t, get_eap_msk, chunk_t,
+	private_tls_crypto_t *this)
+{
+	return this->msk;
+}
+
+METHOD(tls_crypto_t, destroy, void,
+	private_tls_crypto_t *this)
+{
+	DESTROY_IF(this->signer_in);
+	DESTROY_IF(this->signer_out);
+	DESTROY_IF(this->crypter_in);
+	DESTROY_IF(this->crypter_out);
+	free(this->iv_in.ptr);
+	free(this->iv_out.ptr);
+	free(this->handshake.ptr);
+	free(this->msk.ptr);
+	DESTROY_IF(this->prf);
+	free(this->suites);
+	free(this);
+}
+
+/**
+ * See header
+ */
+tls_crypto_t *tls_crypto_create(tls_t *tls)
+{
+	private_tls_crypto_t *this;
+
+	INIT(this,
+		.public = {
+			.get_cipher_suites = _get_cipher_suites,
+			.select_cipher_suite = _select_cipher_suite,
+			.set_protection = _set_protection,
+			.append_handshake = _append_handshake,
+			.sign_handshake = _sign_handshake,
+			.verify_handshake = _verify_handshake,
+			.calculate_finished = _calculate_finished,
+			.derive_secrets = _derive_secrets,
+			.change_cipher = _change_cipher,
+			.derive_eap_msk = _derive_eap_msk,
+			.get_eap_msk = _get_eap_msk,
+			.destroy = _destroy,
+		},
+		.tls = tls,
+	);
+
+	build_cipher_suite_list(this);
+
+	return &this->public;
+}