specifying keysize in bits, as it is required in IKEv2

added generic kernel SA algorithm handling, which brings us:
        aes-128, aes-256, blowfish, des, 3des and null encryption for CHILD_SAs

src/charon/config/proposal.h

@@ -112,7 +112,7 @@ struct algorithm_t {
 	u_int16_t algorithm;
 	
 	/**
-	 * the associated key size, or zero if not needed
+	 * the associated key size in bits, or zero if not needed
 	 */
 	u_int16_t key_size;
 };

src/charon/encoding/payloads/transform_substructure.c

@@ -473,9 +473,12 @@ transform_substructure_t *transform_substructure_create_type(transform_type_t tr
 	transform->set_transform_type(transform,transform_type);
 	transform->set_transform_id(transform,transform_id);
 	
-	/* a keylength attribute is only created for AES encryption */
+	/* a keylength attribute is only created for variable length algos */
 	if (transform_type == ENCRYPTION_ALGORITHM &&
-		transform_id == ENCR_AES_CBC)
+		(transform_id == ENCR_AES_CBC ||
+		 transform_id == ENCR_IDEA ||
+		 transform_id == ENCR_CAST ||
+		 transform_id == ENCR_BLOWFISH))
 	{
 		transform_attribute_t *attribute = transform_attribute_create_key_length(key_length);
 		transform->add_transform_attribute(transform,attribute);

src/charon/sa/child_sa.c

@@ -164,13 +164,9 @@ static status_t alloc(private_child_sa_t *this, linked_list_t *proposals)
 static status_t install(private_child_sa_t *this, proposal_t *proposal, prf_plus_t *prf_plus, bool mine)
 {
 	u_int32_t spi;
-	encryption_algorithm_t enc_algo;
+	algorithm_t *enc_algo, *int_algo;
-	integrity_algorithm_t int_algo;
+	algorithm_t enc_algo_none = {ENCR_UNDEFINED, 0};
-	chunk_t enc_key, int_key;
+	algorithm_t int_algo_none = {AUTH_UNDEFINED, 0};
-	algorithm_t *algo;
-	crypter_t *crypter;
-	signer_t *signer;
-	size_t key_size;
 	host_t *src;
 	host_t *dst;
 	status_t status;
@@ -201,75 +197,44 @@ static status_t install(private_child_sa_t *this, proposal_t *proposal, prf_plus
 		this->other.spi = spi;
 	}
 	
-	/* derive encryption key first */
+	this->logger->log(this->logger, CONTROL|LEVEL1, "Adding %s %s SA",
-	if (proposal->get_algorithm(proposal, ENCRYPTION_ALGORITHM, &algo))
+					  mine ? "inbound" : "outbound",
-	{
+					  mapping_find(protocol_id_m, this->protocol));
-		enc_algo = algo->algorithm;
-		this->logger->log(this->logger, CONTROL|LEVEL1, "%s for %s: using %s %s, ",
-							mapping_find(protocol_id_m, this->protocol),
-							mine ? "me" : "other",
-							mapping_find(transform_type_m, ENCRYPTION_ALGORITHM),
-							mapping_find(encryption_algorithm_m, enc_algo));
 	
-		/* we must create a (unused) crypter, since its the only way to get the size
+	/* select encryption algo */
-		 * of the key. This is not so nice, since charon must support all algorithms
+	if (proposal->get_algorithm(proposal, ENCRYPTION_ALGORITHM, &enc_algo))
-		 * the kernel supports...
+	{
-		 * TODO: build something of a encryption algorithm lookup function 
+		this->logger->log(this->logger, CONTROL|LEVEL2, "  using %s for encryption",
-		 */
+							mapping_find(encryption_algorithm_m, enc_algo->algorithm));
-		crypter = crypter_create(enc_algo, algo->key_size);
-		key_size = crypter->get_key_size(crypter);
-		crypter->destroy(crypter);
-		prf_plus->allocate_bytes(prf_plus, key_size, &enc_key);
-		this->logger->log_chunk(this->logger, PRIVATE, "key:", enc_key);
 	}
 	else
 	{
-		enc_algo = ENCR_UNDEFINED;
+		enc_algo = &enc_algo_none;
 	}
 	
-	/* derive integrity key */
+	/* select integrity algo */
-	if (proposal->get_algorithm(proposal, INTEGRITY_ALGORITHM, &algo))
+	if (proposal->get_algorithm(proposal, INTEGRITY_ALGORITHM, &int_algo))
 	{
-		int_algo = algo->algorithm;
+		this->logger->log(this->logger, CONTROL|LEVEL2, "  using %s for integrity",
-		this->logger->log(this->logger, CONTROL|LEVEL1, "%s for %s: using %s %s,",
+						  mapping_find(integrity_algorithm_m, int_algo->algorithm));
-							mapping_find(protocol_id_m, this->protocol),
-							mine ? "me" : "other",
-							mapping_find(transform_type_m, INTEGRITY_ALGORITHM),
-							mapping_find(integrity_algorithm_m, algo->algorithm));
-		
-		signer = signer_create(int_algo);
-		key_size = signer->get_key_size(signer);
-		signer->destroy(signer);
-		prf_plus->allocate_bytes(prf_plus, key_size, &int_key);
-		this->logger->log_chunk(this->logger, PRIVATE, "key:", int_key);
 	}
 	else
 	{
-		int_algo = AUTH_UNDEFINED;
+		int_algo = &int_algo_none;
 	}
 	
-	/* send keys down to kernel */
+	/* send SA down to the kernel */
-	this->logger->log(this->logger, CONTROL|LEVEL1, 
+	this->logger->log(this->logger, CONTROL|LEVEL2,
-						"installing 0x%.8x for %s, src %s dst %s",
+						"  SPI 0x%.8x, src %s dst %s",
-						ntohl(spi), mapping_find(protocol_id_m, this->protocol), 
+						ntohl(spi), src->get_address(src), dst->get_address(dst));
-						src->get_address(src), dst->get_address(dst));
 	status = charon->kernel_interface->add_sa(charon->kernel_interface,
 												src, dst,
 												spi, this->protocol,
 												this->reqid,
 												mine ? 0 : this->soft_lifetime,
 												this->hard_lifetime,
-												enc_algo, enc_key,
+												enc_algo, int_algo, prf_plus, mine);
-												int_algo, int_key, mine);
+
-	/* clean up */
-	if (enc_algo != ENCR_UNDEFINED)
-	{
-		chunk_free(&enc_key);
-	}
-	if (int_algo != AUTH_UNDEFINED)
-	{
-		chunk_free(&int_key);
-	}
 	return status;
 }
 

src/charon/sa/ike_sa.c

@@ -486,8 +486,8 @@ static status_t build_transforms(private_ike_sa_t *this, proposal_t *proposal, d
 		this->crypter_responder->destroy(this->crypter_responder);
 	}
 	
-	this->crypter_initiator = crypter_create(algo->algorithm, algo->key_size);
+	this->crypter_initiator = crypter_create(algo->algorithm, algo->key_size / 8);
-	this->crypter_responder = crypter_create(algo->algorithm, algo->key_size);
+	this->crypter_responder = crypter_create(algo->algorithm, algo->key_size / 8);
 	if (this->crypter_initiator == NULL || this->crypter_responder == NULL)
 	{
 		this->logger->log(this->logger, ERROR|LEVEL1, 

src/charon/testing/kernel_interface_test.c

@@ -39,24 +39,18 @@ void test_kernel_interface(protected_tester_t *tester)
 	u_int32_t spi;
 	host_t *me, *other, *left, *right;
 	status_t status;
-	
+	prf_plus_t *prf_plus;
-	u_int8_t enc_key_bytes[] = {
+	prf_t *prf;	
-		0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,
+	u_int8_t key_bytes[] = {
 		0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08
 	};
+	chunk_t key = chunk_from_buf(key_bytes);
+	algorithm_t int_alg = {AUTH_HMAC_MD5_96, 0};
+	algorithm_t enc_alg = {ENCR_AES_CBC, 128};
 	
-	u_int8_t inc_key_bytes[] = {
+	prf = prf_create(PRF_HMAC_MD5);
-		0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,
+	prf->set_key(prf, key);
-		0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08
+	prf_plus = prf_plus_create(prf, key);	
-	};
-	
-	chunk_t enc_key,inc_key;
-	enc_key.ptr = enc_key_bytes;
-	enc_key.len = sizeof(enc_key_bytes);
-	inc_key.ptr = inc_key_bytes;
-	inc_key.len = sizeof(inc_key_bytes);
-	
-	
 	
 	kernel_interface = kernel_interface_create();
 	
@@ -66,7 +60,7 @@ void test_kernel_interface(protected_tester_t *tester)
 	status = kernel_interface->get_spi(kernel_interface, me, other, 50, 1234, &spi);
 	tester->assert_true(tester, status == SUCCESS, "spi get");
 	
-	status = kernel_interface->add_sa(kernel_interface, me, other, spi, 50, 1234, 5, 10, ENCR_AES_CBC, enc_key,AUTH_UNDEFINED,inc_key,TRUE);	
+	status = kernel_interface->add_sa(kernel_interface, me, other, spi, 50, 1234, 5, 10, &enc_alg, &int_alg, prf_plus,  TRUE);	
 	tester->assert_true(tester, status == SUCCESS, "add sa");
 	
 	left = host_create(AF_INET, "10.1.0.0", 0);

src/charon/threads/kernel_interface.c

@@ -45,7 +45,7 @@
 
 #define SPD_PRIORITY 1024
 
-#define XFRM_DATA_LENGTH 512
+#define XFRM_DATA_LENGTH 1024
 
 
 typedef struct xfrm_data_t xfrm_data_t;
@@ -109,6 +109,85 @@ struct netlink_message_t {
 	u_int8_t data[XFRM_DATA_LENGTH];
 };
 
+typedef struct kernel_algorithm_t kernel_algorithm_t;
+
+/**
+ * Mapping from the algorithms defined in IKEv2 to
+ * kernel level algorithm names and their key length
+ */
+struct kernel_algorithm_t {
+	/**
+	 * Identifier specified in IKEv2
+	 */
+	int ikev2_id;
+	
+	/**
+	 * Name of the algorithm, as used as kernel identifier
+	 */
+	char *name;
+	
+	/**
+	 * Key length in bits, if fixed size
+	 */
+	u_int key_size;
+};
+#define END_OF_LIST -1
+
+/**
+ * Algorithms for encryption
+ */
+kernel_algorithm_t encryption_algs[] = {
+/*	{ENCR_DES_IV64, 	"***", 			0}, */
+	{ENCR_DES, 			"des", 			64},
+	{ENCR_3DES, 		"des3_ede",		192},
+/*	{ENCR_RC5, 			"***", 			0}, */
+/*	{ENCR_IDEA, 		"***",			0}, */
+	{ENCR_CAST, 		"cast128",		0},
+	{ENCR_BLOWFISH, 	"blowfish",		0},
+/*	{ENCR_3IDEA, 		"***",			0}, */
+/*	{ENCR_DES_IV32, 	"***",			0}, */
+	{ENCR_NULL, 		"cipher_null",	0},
+	{ENCR_AES_CBC, 		"aes",			0},
+/*	{ENCR_AES_CTR, 		"***",			0}, */
+	{END_OF_LIST, 		NULL,			0},
+};
+
+/**
+ * Algorithms for integrity protection
+ */
+kernel_algorithm_t integrity_algs[] = {
+	{AUTH_HMAC_MD5_96, 	"md5",			128},
+	{AUTH_HMAC_SHA1_96,	"sha1",			160},
+/*	{AUTH_DES_MAC,		"***",			0}, */
+/*	{AUTH_KPDK_MD5,		"***",			0}, */
+/*	{AUTH_AES_XCBC_96,	"***",			0}, */
+	{END_OF_LIST, 		NULL,			0},
+};
+
+/**
+ * Look up a kernel algorithm name and its key size
+ */
+char* lookup_algorithm(kernel_algorithm_t *kernel_algo, algorithm_t *ikev2_algo, u_int *key_size)
+{
+	while (kernel_algo->ikev2_id != END_OF_LIST)
+	{
+		if (ikev2_algo->algorithm == kernel_algo->ikev2_id)
+		{
+			/* match, evaluate key length */
+			if (ikev2_algo->key_size)
+			{	/* variable length */
+				*key_size = ikev2_algo->key_size;
+			}
+			else
+			{	/* fixed length */
+				*key_size = kernel_algo->key_size;
+			}
+			return kernel_algo->name;
+		}
+		kernel_algo++;
+	}
+	return NULL;	
+}
 
 typedef struct private_kernel_interface_t private_kernel_interface_t;
 
@@ -173,42 +252,6 @@ struct private_kernel_interface_t {
 	status_t (*send_message) (private_kernel_interface_t *this, netlink_message_t *request, netlink_message_t **response);
 };
 
-/**
- * In the kernel, algorithms are identified as strings, we use our
- * mapping functions...
- * Algorithms for encryption.
- * TODO: Add missing algorithm strings
- */
-mapping_t kernel_encryption_algs_m[] = {
-	{ENCR_DES_IV64, ""},
-	{ENCR_DES, "des"},
-	{ENCR_3DES, "des3_ede"},
-	{ENCR_RC5, ""},
-	{ENCR_IDEA, "idea"},
-	{ENCR_CAST, "cast128"},
-	{ENCR_BLOWFISH, "blowfish"},
-	{ENCR_3IDEA, ""},
-	{ENCR_DES_IV32, ""},
-	{ENCR_NULL, ""},
-	{ENCR_AES_CBC, "aes"},
-	{ENCR_AES_CTR, ""},
-	{MAPPING_END, NULL}
-};
-/**
- * In the kernel, algorithms are identified as strings, we use our
- * mapping functions...
- * Algorithms for integrity protection.
- * TODO: Add missing algorithm strings
- */
-mapping_t kernel_integrity_algs_m[] = {
-	{AUTH_HMAC_MD5_96, "md5"},
-	{AUTH_HMAC_SHA1_96, "sha1"},
-	{AUTH_DES_MAC, ""},
-	{AUTH_KPDK_MD5, ""},
-	{AUTH_AES_XCBC_96, ""},
-	{MAPPING_END, NULL}
-};
-
 /**
  * Implementation of kernel_interface_t.get_spi.
  */
@@ -277,15 +320,17 @@ static status_t add_sa(	private_kernel_interface_t *this,
 						u_int32_t reqid,
 						u_int64_t expire_soft,
 						u_int64_t expire_hard,
-						encryption_algorithm_t enc_alg,
+						algorithm_t *enc_alg,
-						chunk_t encryption_key,
+						algorithm_t *int_alg,
-						integrity_algorithm_t int_alg,
+						prf_plus_t *prf_plus,
-						chunk_t integrity_key,
 						bool replace)
 {
 	netlink_message_t request, *response;
-	memset(&request, 0, sizeof(request));
 	status_t status = SUCCESS;
+	int key_size;
+	char *alg_name;
+	
+	memset(&request, 0, sizeof(request));
 	
 	this->logger->log(this->logger, CONTROL|LEVEL2, "adding SA");
 	
@@ -314,36 +359,52 @@ static status_t add_sa(	private_kernel_interface_t *this,
 	
 	request.hdr.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(request.sa)));
 	
-	if (enc_alg != ENCR_UNDEFINED)
+	if (enc_alg->algorithm != ENCR_UNDEFINED)
 	{
 		xfrm_data_t *data = (xfrm_data_t*)(((u_int8_t*)&request) + request.hdr.nlmsg_len);
 		
 		data->type = XFRMA_ALG_CRYPT;
-		data->length = 4 + sizeof(data->algo) + encryption_key.len;
+		alg_name = lookup_algorithm(encryption_algs, enc_alg, &key_size);
-		data->algo.alg_key_len = encryption_key.len * 8;
+		if (alg_name == NULL)
+		{
+			this->logger->log(this->logger, ERROR, "Algorithm %s not supported by kernel!", 
+							  mapping_find(encryption_algorithm_m, enc_alg->algorithm));
+			return FAILED;
+		}
+		this->logger->log(this->logger, CONTROL|LEVEL2, "using key size %d", key_size);
+		data->length = 4 + sizeof(data->algo) + key_size;
+		data->algo.alg_key_len = key_size;
 		request.hdr.nlmsg_len += data->length;
 		if (request.hdr.nlmsg_len > sizeof(request))
 		{
 			return FAILED;
 		}
-		strcpy(data->algo.alg_name, mapping_find(kernel_encryption_algs_m, enc_alg));
+		strcpy(data->algo.alg_name, alg_name);
-		memcpy(data->algo.alg_key, encryption_key.ptr, encryption_key.len);
+		prf_plus->get_bytes(prf_plus, key_size / 8, data->algo.alg_key);
 	}
 	
-	if (int_alg != AUTH_UNDEFINED)
+	if (int_alg->algorithm  != AUTH_UNDEFINED)
 	{
 		xfrm_data_t *data = (xfrm_data_t*)(((u_int8_t*)&request) + request.hdr.nlmsg_len);
 		
 		data->type = XFRMA_ALG_AUTH;
-		data->length = 4 + sizeof(data->algo) + integrity_key.len;
+		alg_name = lookup_algorithm(integrity_algs, int_alg, &key_size);
-		data->algo.alg_key_len = integrity_key.len * 8;
+		if (alg_name == NULL)
+		{
+			this->logger->log(this->logger, ERROR, "Algorithm %s not supported by kernel!", 
+							  mapping_find(integrity_algorithm_m, int_alg->algorithm));
+			return FAILED;
+		}
+		this->logger->log(this->logger, CONTROL|LEVEL2, "using key size %d", key_size);
+		data->length = 4 + sizeof(data->algo) + key_size;
+		data->algo.alg_key_len = key_size;
 		request.hdr.nlmsg_len += data->length;
 		if (request.hdr.nlmsg_len > sizeof(request))
 		{
 			return FAILED;
 		}
-		strcpy(data->algo.alg_name, mapping_find(kernel_integrity_algs_m, int_alg));
+		strcpy(data->algo.alg_name, alg_name);
-		memcpy(data->algo.alg_key, integrity_key.ptr, integrity_key.len);
+		prf_plus->get_bytes(prf_plus, key_size / 8, data->algo.alg_key);
 	}
 	
 	/* TODO: add IPComp here*/
@@ -739,7 +800,7 @@ kernel_interface_t *kernel_interface_create()
 	
 	/* public functions */
 	this->public.get_spi = (status_t(*)(kernel_interface_t*,host_t*,host_t*,protocol_id_t,u_int32_t,u_int32_t*))get_spi;
-	this->public.add_sa  = (status_t(*)(kernel_interface_t *,host_t*,host_t*,u_int32_t,protocol_id_t,u_int32_t,u_int64_t,u_int64_t,encryption_algorithm_t,chunk_t,integrity_algorithm_t,chunk_t,bool))add_sa;
+	this->public.add_sa  = (status_t(*)(kernel_interface_t *,host_t*,host_t*,u_int32_t,protocol_id_t,u_int32_t,u_int64_t,u_int64_t,algorithm_t*,algorithm_t*,prf_plus_t*,bool))add_sa;
 	this->public.add_policy = (status_t(*)(kernel_interface_t*,host_t*, host_t*,host_t*,host_t*,u_int8_t,u_int8_t,int,int,bool,bool,u_int32_t))add_policy;
 	this->public.del_sa = (status_t(*)(kernel_interface_t*,host_t*,u_int32_t,protocol_id_t))del_sa;
 	this->public.del_policy = (status_t(*)(kernel_interface_t*,host_t*,host_t*,host_t*,host_t*,u_int8_t,u_int8_t,int,int))del_policy;

src/charon/threads/kernel_interface.h

@@ -26,6 +26,7 @@
 #include <linux/xfrm.h>
 
 #include <utils/host.h>
+#include <crypto/prf_plus.h>
 #include <encoding/payloads/proposal_substructure.h>
 
 typedef struct kernel_interface_t kernel_interface_t;
@@ -70,7 +71,9 @@ struct kernel_interface_t {
 	 * SPI (via get_spi). In this case, the replace
 	 * flag must be set.
 	 * This function does install a single SA for a
-	 * single protocol in one direction.
+	 * single protocol in one direction. The kernel-interface
+	 * gets the keys itself from the PRF, as we don't know
+	 * his algorithms and key sizes.
 	 * 
 	 * @param this			calling object
 	 * @param src			source address for this SA
@@ -81,9 +84,8 @@ struct kernel_interface_t {
 	 * @param expire_soft	lifetime in seconds before rekeying
 	 * @param expire_hard	lieftime in seconds before delete
 	 * @param enc_alg		Algorithm to use for encryption (ESP only)
-	 * @param enc_key		Key to use for encryption
 	 * @param int_alg		Algorithm to use for integrity protection
-	 * @param int_key		Key for integrity protection
+	 * @param prf_plus		PRF to derive keys
 	 * @param replace		Should an already installed SA be updated?
 	 * @return
 	 * 						- SUCCESS
@@ -96,10 +98,9 @@ struct kernel_interface_t {
 				u_int32_t reqid,
 				u_int64_t expire_soft,
 				u_int64_t expire_hard,
-				encryption_algorithm_t enc_alg,
+				algorithm_t *enc_alg,
-				chunk_t enc_key,
+				algorithm_t *int_alg,
-				integrity_algorithm_t int_alg,
+				prf_plus_t *prf_plus,
-				chunk_t int_key,
 				bool replace);
 	/**
 	 * @brief Delete a previusly installed SA from the SAD.

src/charon/threads/stroke_interface.c

@@ -311,7 +311,7 @@ static void stroke_add_conn(private_stroke_t *this, stroke_msg_t *msg)
 								   my_host, other_host,
 								   RSA_DIGITAL_SIGNATURE);
 	proposal = proposal_create(PROTO_IKE);
-	proposal->add_algorithm(proposal, ENCRYPTION_ALGORITHM, ENCR_AES_CBC, 16);
+	proposal->add_algorithm(proposal, ENCRYPTION_ALGORITHM, ENCR_AES_CBC, 128);
 	proposal->add_algorithm(proposal, INTEGRITY_ALGORITHM, AUTH_HMAC_SHA1_96, 0);
 	proposal->add_algorithm(proposal, INTEGRITY_ALGORITHM, AUTH_HMAC_MD5_96, 0);
 	proposal->add_algorithm(proposal, PSEUDO_RANDOM_FUNCTION, PRF_HMAC_SHA1, 0);
@@ -334,8 +334,12 @@ static void stroke_add_conn(private_stroke_t *this, stroke_msg_t *msg)
 	
 	policy = policy_create(msg->add_conn.name, my_id, other_id);
 	proposal = proposal_create(PROTO_ESP);
-	proposal->add_algorithm(proposal, ENCRYPTION_ALGORITHM, ENCR_AES_CBC, 16);
+	proposal->add_algorithm(proposal, ENCRYPTION_ALGORITHM, ENCR_AES_CBC, 128);
+	proposal->add_algorithm(proposal, ENCRYPTION_ALGORITHM, ENCR_AES_CBC, 256);
+	proposal->add_algorithm(proposal, ENCRYPTION_ALGORITHM, ENCR_3DES, 0);
+	proposal->add_algorithm(proposal, ENCRYPTION_ALGORITHM, ENCR_BLOWFISH, 256);
 	proposal->add_algorithm(proposal, INTEGRITY_ALGORITHM, AUTH_HMAC_SHA1_96, 0);
+	proposal->add_algorithm(proposal, INTEGRITY_ALGORITHM, AUTH_HMAC_MD5_96, 0);
 	policy->add_proposal(policy, proposal);
 	policy->add_my_traffic_selector(policy, my_ts);
 	policy->add_other_traffic_selector(policy, other_ts);
@@ -514,6 +518,7 @@ logger_context_t get_context(char *context)
 	else if (strcasecmp(context, "CONFG") == 0) return CONFIG;
 	else if (strcasecmp(context, "ENCPL") == 0) return ENCRYPTION_PAYLOAD;
 	else if (strcasecmp(context, "PAYLD") == 0) return PAYLOAD;
+	else if (strcasecmp(context, "XFRM") == 0) return XFRM;
 	else return -2;
 }