1 /*
2  * IKEv2 definitions
3  * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #ifndef IKEV2_COMMON_H
10 #define IKEV2_COMMON_H
11 
12 /*
13  * Nonce length must be at least 16 octets. It must also be at least half the
14  * key size of the negotiated PRF.
15  */
16 #define IKEV2_NONCE_MIN_LEN 16
17 #define IKEV2_NONCE_MAX_LEN 256
18 
19 /* IKE Header - RFC 4306, Sect. 3.1 */
20 #ifdef _MSC_VER
21 #pragma pack(push, 1)
22 #endif /* _MSC_VER */
23 
24 #define IKEV2_SPI_LEN 8
25 
26 struct ikev2_hdr {
27 	u8 i_spi[IKEV2_SPI_LEN]; /* IKE_SA Initiator's SPI */
28 	u8 r_spi[IKEV2_SPI_LEN]; /* IKE_SA Responder's SPI */
29 	u8 next_payload;
30 	u8 version; /* MjVer | MnVer */
31 	u8 exchange_type;
32 	u8 flags;
33 	u8 message_id[4];
34 	u8 length[4]; /* total length of HDR + payloads */
35 } STRUCT_PACKED;
36 
37 struct ikev2_payload_hdr {
38 	u8 next_payload;
39 	u8 flags;
40 	u8 payload_length[2]; /* this payload, including the payload header */
41 } STRUCT_PACKED;
42 
43 struct ikev2_proposal {
44 	u8 type; /* 0 (last) or 2 (more) */
45 	u8 reserved;
46 	u8 proposal_length[2]; /* including all transform and attributes */
47 	u8 proposal_num;
48 	u8 protocol_id; /* IKEV2_PROTOCOL_* */
49 	u8 spi_size;
50 	u8 num_transforms;
51 	/* SPI of spi_size octets */
52 	/* Transforms */
53 } STRUCT_PACKED;
54 
55 struct ikev2_transform {
56 	u8 type; /* 0 (last) or 3 (more) */
57 	u8 reserved;
58 	u8 transform_length[2]; /* including Header and Attributes */
59 	u8 transform_type;
60 	u8 reserved2;
61 	u8 transform_id[2];
62 	/* Transform Attributes */
63 } STRUCT_PACKED;
64 
65 #ifdef _MSC_VER
66 #pragma pack(pop)
67 #endif /* _MSC_VER */
68 
69 
70 /* Current IKEv2 version from RFC 4306 */
71 #define IKEV2_MjVer 2
72 #define IKEV2_MnVer 0
73 #ifdef CCNS_PL
74 #define IKEV2_VERSION ((IKEV2_MjVer) | ((IKEV2_MnVer) << 4))
75 #else /* CCNS_PL */
76 #define IKEV2_VERSION (((IKEV2_MjVer) << 4) | (IKEV2_MnVer))
77 #endif /* CCNS_PL */
78 
79 /* IKEv2 Exchange Types */
80 enum {
81 	/* 0-33 RESERVED */
82 	IKE_SA_INIT = 34,
83 	IKE_SA_AUTH = 35,
84 	CREATE_CHILD_SA = 36,
85 	INFORMATION = 37
86 	/* 38-239 RESERVED TO IANA */
87 	/* 240-255 Reserved for private use */
88 };
89 
90 /* IKEv2 Flags */
91 #define IKEV2_HDR_INITIATOR	0x08
92 #define IKEV2_HDR_VERSION	0x10
93 #define IKEV2_HDR_RESPONSE	0x20
94 
95 /* Payload Header Flags */
96 #define IKEV2_PAYLOAD_FLAGS_CRITICAL 0x01
97 
98 
99 /* EAP-IKEv2 Payload Types (in Next Payload Type field)
100  * http://www.iana.org/assignments/eap-ikev2-payloads */
101 enum {
102 	IKEV2_PAYLOAD_NO_NEXT_PAYLOAD = 0,
103 	IKEV2_PAYLOAD_SA = 33,
104 	IKEV2_PAYLOAD_KEY_EXCHANGE = 34,
105 	IKEV2_PAYLOAD_IDi = 35,
106 	IKEV2_PAYLOAD_IDr = 36,
107 	IKEV2_PAYLOAD_CERTIFICATE = 37,
108 	IKEV2_PAYLOAD_CERT_REQ = 38,
109 	IKEV2_PAYLOAD_AUTHENTICATION = 39,
110 	IKEV2_PAYLOAD_NONCE = 40,
111 	IKEV2_PAYLOAD_NOTIFICATION = 41,
112 	IKEV2_PAYLOAD_VENDOD_ID = 43,
113 	IKEV2_PAYLOAD_ENCRYPTED = 46,
114 	IKEV2_PAYLOAD_NEXT_FAST_ID = 121
115 };
116 
117 
118 /* IKEv2 Proposal - Protocol ID */
119 enum {
120 	IKEV2_PROTOCOL_RESERVED = 0,
121 	IKEV2_PROTOCOL_IKE = 1, /* IKE is the only one allowed for EAP-IKEv2 */
122 	IKEV2_PROTOCOL_AH = 2,
123 	IKEV2_PROTOCOL_ESP = 3
124 };
125 
126 
127 /* IKEv2 Transform Types */
128 enum {
129 	IKEV2_TRANSFORM_ENCR = 1,
130 	IKEV2_TRANSFORM_PRF = 2,
131 	IKEV2_TRANSFORM_INTEG = 3,
132 	IKEV2_TRANSFORM_DH = 4,
133 	IKEV2_TRANSFORM_ESN = 5
134 };
135 
136 /* IKEv2 Transform Type 1 (Encryption Algorithm) */
137 enum {
138 	ENCR_DES_IV64 = 1,
139 	ENCR_DES = 2,
140 	ENCR_3DES = 3,
141 	ENCR_RC5 = 4,
142 	ENCR_IDEA = 5,
143 	ENCR_CAST = 6,
144 	ENCR_BLOWFISH = 7,
145 	ENCR_3IDEA = 8,
146 	ENCR_DES_IV32 = 9,
147 	ENCR_NULL = 11,
148 	ENCR_AES_CBC = 12,
149 	ENCR_AES_CTR = 13
150 };
151 
152 /* IKEv2 Transform Type 2 (Pseudo-random Function) */
153 enum {
154 	PRF_HMAC_MD5 = 1,
155 	PRF_HMAC_SHA1 = 2,
156 	PRF_HMAC_TIGER = 3,
157 	PRF_AES128_XCBC = 4
158 };
159 
160 /* IKEv2 Transform Type 3 (Integrity Algorithm) */
161 enum {
162 	AUTH_HMAC_MD5_96 = 1,
163 	AUTH_HMAC_SHA1_96 = 2,
164 	AUTH_DES_MAC = 3,
165 	AUTH_KPDK_MD5 = 4,
166 	AUTH_AES_XCBC_96 = 5
167 };
168 
169 /* IKEv2 Transform Type 4 (Diffie-Hellman Group) */
170 enum {
171 	DH_GROUP1_768BIT_MODP = 1, /* RFC 4306 */
172 	DH_GROUP2_1024BIT_MODP = 2, /* RFC 4306 */
173 	DH_GROUP5_1536BIT_MODP = 5, /* RFC 3526 */
174 	DH_GROUP5_2048BIT_MODP = 14, /* RFC 3526 */
175 	DH_GROUP5_3072BIT_MODP = 15, /* RFC 3526 */
176 	DH_GROUP5_4096BIT_MODP = 16, /* RFC 3526 */
177 	DH_GROUP5_6144BIT_MODP = 17, /* RFC 3526 */
178 	DH_GROUP5_8192BIT_MODP = 18 /* RFC 3526 */
179 };
180 
181 
182 /* Identification Data Types (RFC 4306, Sect. 3.5) */
183 enum {
184 	ID_IPV4_ADDR = 1,
185 	ID_FQDN = 2,
186 	ID_RFC822_ADDR = 3,
187 	ID_IPV6_ADDR = 5,
188 	ID_DER_ASN1_DN = 9,
189 	ID_DER_ASN1_GN= 10,
190 	ID_KEY_ID = 11
191 };
192 
193 
194 /* Certificate Encoding (RFC 4306, Sect. 3.6) */
195 enum {
196 	CERT_ENCODING_PKCS7_X509 = 1,
197 	CERT_ENCODING_PGP_CERT = 2,
198 	CERT_ENCODING_DNS_SIGNED_KEY = 3,
199 	/* X.509 Certificate - Signature: DER encoded X.509 certificate whose
200 	 * public key is used to validate the sender's AUTH payload */
201 	CERT_ENCODING_X509_CERT_SIGN = 4,
202 	CERT_ENCODING_KERBEROS_TOKEN = 6,
203 	/* DER encoded X.509 certificate revocation list */
204 	CERT_ENCODING_CRL = 7,
205 	CERT_ENCODING_ARL = 8,
206 	CERT_ENCODING_SPKI_CERT = 9,
207 	CERT_ENCODING_X509_CERT_ATTR = 10,
208 	/* PKCS #1 encoded RSA key */
209 	CERT_ENCODING_RAW_RSA_KEY = 11,
210 	CERT_ENCODING_HASH_AND_URL_X509_CERT = 12,
211 	CERT_ENCODING_HASH_AND_URL_X509_BUNDLE = 13
212 };
213 
214 
215 /* Authentication Method (RFC 4306, Sect. 3.8) */
216 enum {
217 	AUTH_RSA_SIGN = 1,
218 	AUTH_SHARED_KEY_MIC = 2,
219 	AUTH_DSS_SIGN = 3
220 };
221 
222 
223 /* Notify Message Types (RFC 4306, Sect. 3.10.1) */
224 enum {
225 	UNSUPPORTED_CRITICAL_PAYLOAD = 1,
226 	INVALID_IKE_SPI = 4,
227 	INVALID_MAJOR_VERSION = 5,
228 	INVALID_SYNTAX = 7,
229 	INVALID_MESSAGE_ID = 9,
230 	INVALID_SPI = 11,
231 	NO_PROPOSAL_CHOSEN = 14,
232 	INVALID_KE_PAYLOAD = 17,
233 	AUTHENTICATION_FAILED = 24,
234 	SINGLE_PAIR_REQUIRED = 34,
235 	NO_ADDITIONAL_SAS = 35,
236 	INTERNAL_ADDRESS_FAILURE = 36,
237 	FAILED_CP_REQUIRED = 37,
238 	TS_UNACCEPTABLE = 38,
239 	INVALID_SELECTORS = 39
240 };
241 
242 
243 struct ikev2_keys {
244 	u8 *SK_d, *SK_ai, *SK_ar, *SK_ei, *SK_er, *SK_pi, *SK_pr;
245 	size_t SK_d_len, SK_integ_len, SK_encr_len, SK_prf_len;
246 };
247 
248 
249 int ikev2_keys_set(struct ikev2_keys *keys);
250 void ikev2_free_keys(struct ikev2_keys *keys);
251 
252 
253 /* Maximum hash length for supported hash algorithms */
254 #define IKEV2_MAX_HASH_LEN 20
255 
256 struct ikev2_integ_alg {
257 	int id;
258 	size_t key_len;
259 	size_t hash_len;
260 };
261 
262 struct ikev2_prf_alg {
263 	int id;
264 	size_t key_len;
265 	size_t hash_len;
266 };
267 
268 struct ikev2_encr_alg {
269 	int id;
270 	size_t key_len;
271 	size_t block_size;
272 };
273 
274 const struct ikev2_integ_alg * ikev2_get_integ(int id);
275 int ikev2_integ_hash(int alg, const u8 *key, size_t key_len, const u8 *data,
276 		     size_t data_len, u8 *hash);
277 const struct ikev2_prf_alg * ikev2_get_prf(int id);
278 int ikev2_prf_hash(int alg, const u8 *key, size_t key_len,
279 		   size_t num_elem, const u8 *addr[], const size_t *len,
280 		   u8 *hash);
281 int ikev2_prf_plus(int alg, const u8 *key, size_t key_len,
282 		   const u8 *data, size_t data_len,
283 		   u8 *out, size_t out_len);
284 const struct ikev2_encr_alg * ikev2_get_encr(int id);
285 int ikev2_encr_encrypt(int alg, const u8 *key, size_t key_len, const u8 *iv,
286 		       const u8 *plain, u8 *crypt, size_t len);
287 int ikev2_encr_decrypt(int alg, const u8 *key, size_t key_len, const u8 *iv,
288 		       const u8 *crypt, u8 *plain, size_t len);
289 
290 int ikev2_derive_auth_data(int prf_alg, const struct wpabuf *sign_msg,
291 			   const u8 *ID, size_t ID_len, u8 ID_type,
292 			   struct ikev2_keys *keys, int initiator,
293 			   const u8 *shared_secret, size_t shared_secret_len,
294 			   const u8 *nonce, size_t nonce_len,
295 			   const u8 *key_pad, size_t key_pad_len,
296 			   u8 *auth_data);
297 
298 
299 struct ikev2_payloads {
300 	const u8 *sa;
301 	size_t sa_len;
302 	const u8 *ke;
303 	size_t ke_len;
304 	const u8 *idi;
305 	size_t idi_len;
306 	const u8 *idr;
307 	size_t idr_len;
308 	const u8 *cert;
309 	size_t cert_len;
310 	const u8 *auth;
311 	size_t auth_len;
312 	const u8 *nonce;
313 	size_t nonce_len;
314 	const u8 *encrypted;
315 	size_t encrypted_len;
316 	u8 encr_next_payload;
317 	const u8 *notification;
318 	size_t notification_len;
319 };
320 
321 int ikev2_parse_payloads(struct ikev2_payloads *payloads,
322 			 u8 next_payload, const u8 *pos, const u8 *end);
323 
324 u8 * ikev2_decrypt_payload(int encr_id, int integ_id, struct ikev2_keys *keys,
325 			   int initiator, const struct ikev2_hdr *hdr,
326 			   const u8 *encrypted, size_t encrypted_len,
327 			   size_t *res_len);
328 void ikev2_update_hdr(struct wpabuf *msg);
329 int ikev2_build_encrypted(int encr_id, int integ_id, struct ikev2_keys *keys,
330 			  int initiator, struct wpabuf *msg,
331 			  struct wpabuf *plain, u8 next_payload);
332 int ikev2_derive_sk_keys(const struct ikev2_prf_alg *prf,
333 			 const struct ikev2_integ_alg *integ,
334 			 const struct ikev2_encr_alg *encr,
335 			 const u8 *skeyseed, const u8 *data, size_t data_len,
336 			 struct ikev2_keys *keys);
337 
338 #endif /* IKEV2_COMMON_H */
339