[svn-upgrade] Integrating new upstream version, strongswan (4.4.0)

1 files changed, 617 insertions, 0 deletions

diff --git a/src/libcharon/sa/keymat.c b/src/libcharon/sa/keymat.c
new file mode 100644
index 000000000..837cbe428
--- /dev/null
+++ b/src/libcharon/sa/keymat.c
@@ -0,0 +1,617 @@
+/*
+ * Copyright (C) 2008 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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 "keymat.h"
+
+#include <daemon.h>
+#include <crypto/prf_plus.h>
+
+typedef struct private_keymat_t private_keymat_t;
+
+/**
+ * Private data of an keymat_t object.
+ */
+struct private_keymat_t {
+
+	/**
+	 * Public keymat_t interface.
+	 */
+	keymat_t public;
+
+	/**
+	 * IKE_SA Role, initiator or responder
+	 */
+	bool initiator;
+
+	/**
+	 * inbound signer (verify)
+	 */
+	signer_t *signer_in;
+
+	/**
+	 * outbound signer (sign)
+	 */
+	signer_t *signer_out;
+
+	/**
+	 * inbound crypter (decrypt)
+	 */
+	crypter_t *crypter_in;
+
+	/**
+	 * outbound crypter (encrypt)
+	 */
+	crypter_t *crypter_out;
+
+	/**
+	 * General purpose PRF
+	 */
+	prf_t *prf;
+
+	/**
+	 * Negotiated PRF algorithm
+	 */
+	pseudo_random_function_t prf_alg;
+
+	/**
+	 * Key to derive key material from for CHILD_SAs, rekeying
+	 */
+	chunk_t skd;
+
+	/**
+	 * Key to build outging authentication data (SKp)
+	 */
+	chunk_t skp_build;
+
+	/**
+	 * Key to verify incoming authentication data (SKp)
+	 */
+	chunk_t skp_verify;
+};
+
+typedef struct keylen_entry_t keylen_entry_t;
+
+/**
+ * Implicit key length for an algorithm
+ */
+struct keylen_entry_t {
+	/** IKEv2 algorithm identifier */
+	int algo;
+	/** key length in bits */
+	int len;
+};
+
+#define END_OF_LIST -1
+
+/**
+ * Keylen for encryption algos
+ */
+keylen_entry_t keylen_enc[] = {
+	{ENCR_DES,					 64},
+	{ENCR_3DES,					192},
+	{END_OF_LIST,				  0}
+};
+
+/**
+ * Keylen for integrity algos
+ */
+keylen_entry_t keylen_int[] = {
+	{AUTH_HMAC_MD5_96,			128},
+	{AUTH_HMAC_SHA1_96,			160},
+	{AUTH_HMAC_SHA2_256_96,		256},
+	{AUTH_HMAC_SHA2_256_128,	256},
+	{AUTH_HMAC_SHA2_384_192,	384},
+	{AUTH_HMAC_SHA2_512_256,	512},
+	{AUTH_AES_XCBC_96,			128},
+	{END_OF_LIST,				  0}
+};
+
+/**
+ * Lookup key length of an algorithm
+ */
+static int lookup_keylen(keylen_entry_t *list, int algo)
+{
+	while (list->algo != END_OF_LIST)
+	{
+		if (algo == list->algo)
+		{
+			return list->len;
+		}
+		list++;
+	}
+	return 0;
+}
+
+/**
+ * Implementation of keymat_t.create_dh
+ */
+static diffie_hellman_t* create_dh(private_keymat_t *this,
+								   diffie_hellman_group_t group)
+{
+	return lib->crypto->create_dh(lib->crypto, group);;
+}
+
+/**
+ * Implementation of keymat_t.derive_keys
+ */
+static bool derive_ike_keys(private_keymat_t *this, proposal_t *proposal,
+							diffie_hellman_t *dh, chunk_t nonce_i,
+							chunk_t nonce_r, ike_sa_id_t *id,
+							pseudo_random_function_t rekey_function,
+							chunk_t rekey_skd)
+{
+	chunk_t skeyseed, key, secret, full_nonce, fixed_nonce, prf_plus_seed;
+	chunk_t spi_i, spi_r;
+	crypter_t *crypter_i, *crypter_r;
+	signer_t *signer_i, *signer_r;
+	prf_plus_t *prf_plus;
+	u_int16_t alg, key_size;
+	prf_t *rekey_prf = NULL;
+
+	spi_i = chunk_alloca(sizeof(u_int64_t));
+	spi_r = chunk_alloca(sizeof(u_int64_t));
+
+	if (dh->get_shared_secret(dh, &secret) != SUCCESS)
+	{
+		return FALSE;
+	}
+
+	/* Create SAs general purpose PRF first, we may use it here */
+	if (!proposal->get_algorithm(proposal, PSEUDO_RANDOM_FUNCTION, &alg, NULL))
+	{
+		DBG1(DBG_IKE, "no %N selected",
+			 transform_type_names, PSEUDO_RANDOM_FUNCTION);
+		return FALSE;
+	}
+	this->prf_alg = alg;
+	this->prf = lib->crypto->create_prf(lib->crypto, alg);
+	if (this->prf == NULL)
+	{
+		DBG1(DBG_IKE, "%N %N not supported!",
+			 transform_type_names, PSEUDO_RANDOM_FUNCTION,
+			 pseudo_random_function_names, alg);
+		return FALSE;
+	}
+	DBG4(DBG_IKE, "shared Diffie Hellman secret %B", &secret);
+	/* full nonce is used as seed for PRF+ ... */
+	full_nonce = chunk_cat("cc", nonce_i, nonce_r);
+	/* but the PRF may need a fixed key which only uses the first bytes of
+	 * the nonces. */
+	switch (alg)
+	{
+		case PRF_AES128_XCBC:
+			/* while rfc4434 defines variable keys for AES-XCBC, rfc3664 does
+			 * not and therefore fixed key semantics apply to XCBC for key
+			 * derivation. */
+			key_size = this->prf->get_key_size(this->prf)/2;
+			nonce_i.len = min(nonce_i.len, key_size);
+			nonce_r.len = min(nonce_r.len, key_size);
+			break;
+		default:
+			/* all other algorithms use variable key length, full nonce */
+			break;
+	}
+	fixed_nonce = chunk_cat("cc", nonce_i, nonce_r);
+	*((u_int64_t*)spi_i.ptr) = id->get_initiator_spi(id);
+	*((u_int64_t*)spi_r.ptr) = id->get_responder_spi(id);
+	prf_plus_seed = chunk_cat("ccc", full_nonce, spi_i, spi_r);
+
+	/* KEYMAT = prf+ (SKEYSEED, Ni | Nr | SPIi | SPIr)
+	 *
+	 * if we are rekeying, SKEYSEED is built on another way
+	 */
+	if (rekey_function == PRF_UNDEFINED) /* not rekeying */
+	{
+		/* SKEYSEED = prf(Ni | Nr, g^ir) */
+		this->prf->set_key(this->prf, fixed_nonce);
+		this->prf->allocate_bytes(this->prf, secret, &skeyseed);
+		this->prf->set_key(this->prf, skeyseed);
+		prf_plus = prf_plus_create(this->prf, prf_plus_seed);
+	}
+	else
+	{
+		/* SKEYSEED = prf(SK_d (old), [g^ir (new)] | Ni | Nr)
+		 * use OLD SAs PRF functions for both prf_plus and prf */
+		rekey_prf = lib->crypto->create_prf(lib->crypto, rekey_function);
+		if (!rekey_prf)
+		{
+			DBG1(DBG_IKE, "PRF of old SA %N not supported!",
+				 pseudo_random_function_names, rekey_function);
+			chunk_free(&full_nonce);
+			chunk_free(&fixed_nonce);
+			chunk_clear(&prf_plus_seed);
+			return FALSE;
+		}
+		secret = chunk_cat("mc", secret, full_nonce);
+		rekey_prf->set_key(rekey_prf, rekey_skd);
+		rekey_prf->allocate_bytes(rekey_prf, secret, &skeyseed);
+		rekey_prf->set_key(rekey_prf, skeyseed);
+		prf_plus = prf_plus_create(rekey_prf, prf_plus_seed);
+	}
+	DBG4(DBG_IKE, "SKEYSEED %B", &skeyseed);
+
+	chunk_clear(&skeyseed);
+	chunk_clear(&secret);
+	chunk_free(&full_nonce);
+	chunk_free(&fixed_nonce);
+	chunk_clear(&prf_plus_seed);
+
+	/* KEYMAT = SK_d | SK_ai | SK_ar | SK_ei | SK_er | SK_pi | SK_pr */
+
+	/* SK_d is used for generating CHILD_SA key mat => store for later use */
+	key_size = this->prf->get_key_size(this->prf);
+	prf_plus->allocate_bytes(prf_plus, key_size, &this->skd);
+	DBG4(DBG_IKE, "Sk_d secret %B", &this->skd);
+
+	/* SK_ai/SK_ar used for integrity protection => signer_in/signer_out */
+	if (!proposal->get_algorithm(proposal, INTEGRITY_ALGORITHM, &alg, NULL))
+	{
+		DBG1(DBG_IKE, "no %N selected",
+			 transform_type_names, INTEGRITY_ALGORITHM);
+		prf_plus->destroy(prf_plus);
+		DESTROY_IF(rekey_prf);
+		return FALSE;
+	}
+	signer_i = lib->crypto->create_signer(lib->crypto, alg);
+	signer_r = lib->crypto->create_signer(lib->crypto, alg);
+	if (signer_i == NULL || signer_r == NULL)
+	{
+		DBG1(DBG_IKE, "%N %N not supported!",
+			 transform_type_names, INTEGRITY_ALGORITHM,
+			 integrity_algorithm_names ,alg);
+		prf_plus->destroy(prf_plus);
+		DESTROY_IF(rekey_prf);
+		return FALSE;
+	}
+	key_size = signer_i->get_key_size(signer_i);
+
+	prf_plus->allocate_bytes(prf_plus, key_size, &key);
+	DBG4(DBG_IKE, "Sk_ai secret %B", &key);
+	signer_i->set_key(signer_i, key);
+	chunk_clear(&key);
+
+	prf_plus->allocate_bytes(prf_plus, key_size, &key);
+	DBG4(DBG_IKE, "Sk_ar secret %B", &key);
+	signer_r->set_key(signer_r, key);
+	chunk_clear(&key);
+
+	if (this->initiator)
+	{
+		this->signer_in = signer_r;
+		this->signer_out = signer_i;
+	}
+	else
+	{
+		this->signer_in = signer_i;
+		this->signer_out = signer_r;
+	}
+
+	/* SK_ei/SK_er used for encryption => crypter_in/crypter_out */
+	if (!proposal->get_algorithm(proposal, ENCRYPTION_ALGORITHM, &alg, &key_size))
+	{
+		DBG1(DBG_IKE, "no %N selected",
+			 transform_type_names, ENCRYPTION_ALGORITHM);
+		prf_plus->destroy(prf_plus);
+		DESTROY_IF(rekey_prf);
+		return FALSE;
+	}
+	crypter_i = lib->crypto->create_crypter(lib->crypto, alg, key_size / 8);
+	crypter_r = lib->crypto->create_crypter(lib->crypto, alg, key_size / 8);
+	if (crypter_i == NULL || crypter_r == NULL)
+	{
+		DBG1(DBG_IKE, "%N %N (key size %d) not supported!",
+			 transform_type_names, ENCRYPTION_ALGORITHM,
+			 encryption_algorithm_names, alg, key_size);
+		prf_plus->destroy(prf_plus);
+		DESTROY_IF(rekey_prf);
+		return FALSE;
+	}
+	key_size = crypter_i->get_key_size(crypter_i);
+
+	prf_plus->allocate_bytes(prf_plus, key_size, &key);
+	DBG4(DBG_IKE, "Sk_ei secret %B", &key);
+	crypter_i->set_key(crypter_i, key);
+	chunk_clear(&key);
+
+	prf_plus->allocate_bytes(prf_plus, key_size, &key);
+	DBG4(DBG_IKE, "Sk_er secret %B", &key);
+	crypter_r->set_key(crypter_r, key);
+	chunk_clear(&key);
+
+	if (this->initiator)
+	{
+		this->crypter_in = crypter_r;
+		this->crypter_out = crypter_i;
+	}
+	else
+	{
+		this->crypter_in = crypter_i;
+		this->crypter_out = crypter_r;
+	}
+
+	/* SK_pi/SK_pr used for authentication => stored for later */
+	key_size = this->prf->get_key_size(this->prf);
+	prf_plus->allocate_bytes(prf_plus, key_size, &key);
+	DBG4(DBG_IKE, "Sk_pi secret %B", &key);
+	if (this->initiator)
+	{
+		this->skp_build = key;
+	}
+	else
+	{
+		this->skp_verify = key;
+	}
+	prf_plus->allocate_bytes(prf_plus, key_size, &key);
+	DBG4(DBG_IKE, "Sk_pr secret %B", &key);
+	if (this->initiator)
+	{
+		this->skp_verify = key;
+	}
+	else
+	{
+		this->skp_build = key;
+	}
+
+	/* all done, prf_plus not needed anymore */
+	prf_plus->destroy(prf_plus);
+	DESTROY_IF(rekey_prf);
+
+	return TRUE;
+}
+
+/**
+ * Implementation of keymat_t.derive_child_keys
+ */
+static bool derive_child_keys(private_keymat_t *this,
+							  proposal_t *proposal, diffie_hellman_t *dh,
+							  chunk_t nonce_i, chunk_t nonce_r,
+							  chunk_t *encr_i, chunk_t *integ_i,
+							  chunk_t *encr_r, chunk_t *integ_r)
+{
+	u_int16_t enc_alg, int_alg, enc_size = 0, int_size = 0;
+	chunk_t seed, secret = chunk_empty;
+	prf_plus_t *prf_plus;
+
+	if (dh)
+	{
+		if (dh->get_shared_secret(dh, &secret) != SUCCESS)
+		{
+			return FALSE;
+		}
+		DBG4(DBG_CHD, "DH secret %B", &secret);
+	}
+	seed = chunk_cata("mcc", secret, nonce_i, nonce_r);
+	DBG4(DBG_CHD, "seed %B", &seed);
+
+	if (proposal->get_algorithm(proposal, ENCRYPTION_ALGORITHM,
+								&enc_alg, &enc_size))
+	{
+		DBG2(DBG_CHD, "  using %N for encryption",
+			 encryption_algorithm_names, enc_alg);
+
+		if (!enc_size)
+		{
+			enc_size = lookup_keylen(keylen_enc, enc_alg);
+		}
+		if (enc_alg != ENCR_NULL && !enc_size)
+		{
+			DBG1(DBG_CHD, "no keylength defined for %N",
+				 encryption_algorithm_names, enc_alg);
+			return FALSE;
+		}
+		/* to bytes */
+		enc_size /= 8;
+
+		/* CCM/GCM/CTR/GMAC needs additional bytes */
+		switch (enc_alg)
+		{
+			case ENCR_AES_CCM_ICV8:
+			case ENCR_AES_CCM_ICV12:
+			case ENCR_AES_CCM_ICV16:
+			case ENCR_CAMELLIA_CCM_ICV8:
+			case ENCR_CAMELLIA_CCM_ICV12:
+			case ENCR_CAMELLIA_CCM_ICV16:
+				enc_size += 3;
+				break;
+			case ENCR_AES_GCM_ICV8:
+			case ENCR_AES_GCM_ICV12:
+			case ENCR_AES_GCM_ICV16:
+			case ENCR_AES_CTR:
+			case ENCR_NULL_AUTH_AES_GMAC:
+				enc_size += 4;
+				break;
+			default:
+				break;
+		}
+	}
+
+	if (proposal->get_algorithm(proposal, INTEGRITY_ALGORITHM,
+								&int_alg, &int_size))
+	{
+		DBG2(DBG_CHD, "  using %N for integrity",
+			 integrity_algorithm_names, int_alg);
+
+		if (!int_size)
+		{
+			int_size = lookup_keylen(keylen_int, int_alg);
+		}
+		if (!int_size)
+		{
+			DBG1(DBG_CHD, "no keylength defined for %N",
+				 integrity_algorithm_names, int_alg);
+			return FALSE;
+		}
+		/* to bytes */
+		int_size /= 8;
+	}
+
+	this->prf->set_key(this->prf, this->skd);
+	prf_plus = prf_plus_create(this->prf, seed);
+
+	prf_plus->allocate_bytes(prf_plus, enc_size, encr_i);
+	prf_plus->allocate_bytes(prf_plus, int_size, integ_i);
+	prf_plus->allocate_bytes(prf_plus, enc_size, encr_r);
+	prf_plus->allocate_bytes(prf_plus, int_size, integ_r);
+
+	prf_plus->destroy(prf_plus);
+
+	if (enc_size)
+	{
+		DBG4(DBG_CHD, "encryption initiator key %B", encr_i);
+		DBG4(DBG_CHD, "encryption responder key %B", encr_r);
+	}
+	if (int_size)
+	{
+		DBG4(DBG_CHD, "integrity initiator key %B", integ_i);
+		DBG4(DBG_CHD, "integrity responder key %B", integ_r);
+	}
+	return TRUE;
+}
+
+/**
+ * Implementation of keymat_t.get_skd
+ */
+static pseudo_random_function_t get_skd(private_keymat_t *this, chunk_t *skd)
+{
+	*skd = this->skd;
+	return this->prf_alg;
+}
+
+/**
+ * Implementation of keymat_t.get_signer
+ */
+static signer_t* get_signer(private_keymat_t *this, bool in)
+{
+	return in ? this->signer_in : this->signer_out;
+}
+
+/**
+ * Implementation of keymat_t.get_crypter
+ */
+static crypter_t* get_crypter(private_keymat_t *this, bool in)
+{
+	return in ? this->crypter_in : this->crypter_out;
+}
+
+/**
+ * Implementation of keymat_t.get_auth_octets
+ */
+static chunk_t get_auth_octets(private_keymat_t *this, bool verify,
+							   chunk_t ike_sa_init, chunk_t nonce,
+							   identification_t *id)
+{
+	chunk_t chunk, idx, octets;
+	chunk_t skp;
+
+	skp = verify ? this->skp_verify : this->skp_build;
+
+	chunk = chunk_alloca(4);
+	memset(chunk.ptr, 0, chunk.len);
+	chunk.ptr[0] = id->get_type(id);
+	idx = chunk_cata("cc", chunk, id->get_encoding(id));
+
+	DBG3(DBG_IKE, "IDx' %B", &idx);
+	DBG3(DBG_IKE, "SK_p %B", &skp);
+	this->prf->set_key(this->prf, skp);
+	this->prf->allocate_bytes(this->prf, idx, &chunk);
+
+	octets = chunk_cat("ccm", ike_sa_init, nonce, chunk);
+	DBG3(DBG_IKE, "octets = message + nonce + prf(Sk_px, IDx') %B", &octets);
+	return octets;
+}
+
+/**
+ * Key pad for the AUTH method SHARED_KEY_MESSAGE_INTEGRITY_CODE.
+ */
+#define IKEV2_KEY_PAD "Key Pad for IKEv2"
+#define IKEV2_KEY_PAD_LENGTH 17
+
+/**
+ * Implementation of keymat_t.get_psk_sig
+ */
+static chunk_t get_psk_sig(private_keymat_t *this, bool verify,
+						   chunk_t ike_sa_init, chunk_t nonce, chunk_t secret,
+						   identification_t *id)
+{
+	chunk_t key_pad, key, sig, octets;
+
+	if (!secret.len)
+	{	/* EAP uses SK_p if no MSK has been established */
+		secret = verify ? this->skp_verify : this->skp_build;
+	}
+	octets = get_auth_octets(this, verify, ike_sa_init, nonce, id);
+	/* AUTH = prf(prf(Shared Secret,"Key Pad for IKEv2"), <msg octets>) */
+	key_pad = chunk_create(IKEV2_KEY_PAD, IKEV2_KEY_PAD_LENGTH);
+	this->prf->set_key(this->prf, secret);
+	this->prf->allocate_bytes(this->prf, key_pad, &key);
+	this->prf->set_key(this->prf, key);
+	this->prf->allocate_bytes(this->prf, octets, &sig);
+	DBG4(DBG_IKE, "secret %B", &secret);
+	DBG4(DBG_IKE, "prf(secret, keypad) %B", &key);
+	DBG3(DBG_IKE, "AUTH = prf(prf(secret, keypad), octets) %B", &sig);
+	chunk_free(&octets);
+	chunk_free(&key);
+
+	return sig;
+}
+
+/**
+ * Implementation of keymat_t.destroy.
+ */
+static void destroy(private_keymat_t *this)
+{
+	DESTROY_IF(this->signer_in);
+	DESTROY_IF(this->signer_out);
+	DESTROY_IF(this->crypter_in);
+	DESTROY_IF(this->crypter_out);
+	DESTROY_IF(this->prf);
+	chunk_clear(&this->skd);
+	chunk_clear(&this->skp_verify);
+	chunk_clear(&this->skp_build);
+	free(this);
+}
+
+/**
+ * See header
+ */
+keymat_t *keymat_create(bool initiator)
+{
+	private_keymat_t *this = malloc_thing(private_keymat_t);
+
+	this->public.create_dh = (diffie_hellman_t*(*)(keymat_t*, diffie_hellman_group_t group))create_dh;
+	this->public.derive_ike_keys = (bool(*)(keymat_t*, proposal_t *proposal, diffie_hellman_t *dh, chunk_t nonce_i, chunk_t nonce_r, ike_sa_id_t *id, pseudo_random_function_t,chunk_t))derive_ike_keys;
+	this->public.derive_child_keys = (bool(*)(keymat_t*, proposal_t *proposal, diffie_hellman_t *dh, chunk_t nonce_i, chunk_t nonce_r, chunk_t *encr_i, chunk_t *integ_i, chunk_t *encr_r, chunk_t *integ_r))derive_child_keys;
+	this->public.get_skd = (pseudo_random_function_t(*)(keymat_t*, chunk_t *skd))get_skd;
+	this->public.get_signer = (signer_t*(*)(keymat_t*, bool in))get_signer;
+	this->public.get_crypter = (crypter_t*(*)(keymat_t*, bool in))get_crypter;
+	this->public.get_auth_octets = (chunk_t(*)(keymat_t *, bool verify, chunk_t ike_sa_init, chunk_t nonce, identification_t *id))get_auth_octets;
+	this->public.get_psk_sig = (chunk_t(*)(keymat_t*, bool verify, chunk_t ike_sa_init, chunk_t nonce, chunk_t secret, identification_t *id))get_psk_sig;
+	this->public.destroy = (void(*)(keymat_t*))destroy;
+
+	this->initiator = initiator;
+
+	this->signer_in = NULL;
+	this->signer_out = NULL;
+	this->crypter_in = NULL;
+	this->crypter_out = NULL;
+	this->prf = NULL;
+	this->prf_alg = PRF_UNDEFINED;
+	this->skd = chunk_empty;
+	this->skp_verify = chunk_empty;
+	this->skp_build = chunk_empty;
+
+	return &this->public;
+}
+