eap_pwd_common.h revision c5ec7f57ead87efa365800228aa0b09a12d9e6c4 
1/*
2 * EAP server/peer: EAP-pwd shared definitions
3 * Copyright (c) 2009, Dan Harkins <dharkins@lounge.org>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9#ifndef EAP_PWD_COMMON_H
10#define EAP_PWD_COMMON_H
11
12#include <openssl/bn.h>
13#include <openssl/sha.h>
14#include <openssl/ec.h>
15#include <openssl/evp.h>
16#include <openssl/hmac.h>
17
18/*
19 * definition of a finite cyclic group
20 * TODO: support one based on a prime field
21 */
22typedef struct group_definition_ {
23	u16 group_num;
24	EC_GROUP *group;
25	EC_POINT *pwe;
26	BIGNUM *order;
27	BIGNUM *prime;
28} EAP_PWD_group;
29
30/*
31 * EAP-pwd header, included on all payloads
32 * L(1 bit) | M(1 bit) | exch(6 bits) | total_length(if L is set)
33 */
34#define EAP_PWD_HDR_SIZE                1
35
36#define EAP_PWD_OPCODE_ID_EXCH          1
37#define EAP_PWD_OPCODE_COMMIT_EXCH      2
38#define EAP_PWD_OPCODE_CONFIRM_EXCH     3
39#define EAP_PWD_GET_LENGTH_BIT(x)       ((x) & 0x80)
40#define EAP_PWD_SET_LENGTH_BIT(x)       ((x) |= 0x80)
41#define EAP_PWD_GET_MORE_BIT(x)         ((x) & 0x40)
42#define EAP_PWD_SET_MORE_BIT(x)         ((x) |= 0x40)
43#define EAP_PWD_GET_EXCHANGE(x)         ((x) & 0x3f)
44#define EAP_PWD_SET_EXCHANGE(x,y)       ((x) |= (y))
45
46/* EAP-pwd-ID payload */
47struct eap_pwd_id {
48	be16 group_num;
49	u8 random_function;
50#define EAP_PWD_DEFAULT_RAND_FUNC       1
51	u8 prf;
52#define EAP_PWD_DEFAULT_PRF             1
53	u8 token[4];
54	u8 prep;
55#define EAP_PWD_PREP_NONE               0
56#define EAP_PWD_PREP_MS                 1
57	u8 identity[0];     /* length inferred from payload */
58} STRUCT_PACKED;
59
60/* common routines */
61int compute_password_element(EAP_PWD_group *, u16, u8 *, int, u8 *, int, u8 *,
62			     int, u8 *);
63int compute_keys(EAP_PWD_group *, BN_CTX *, BIGNUM *, BIGNUM *, BIGNUM *,
64		 u8 *, u8 *, u32 *, u8 *, u8 *);
65void H_Init(HMAC_CTX *);
66void H_Update(HMAC_CTX *, const u8 *, int);
67void H_Final(HMAC_CTX *, u8 *);
68
69#endif  /* EAP_PWD_COMMON_H */
70