jpake.h revision 296465 
1/*
2 * Implement J-PAKE, as described in
3 * http://grouper.ieee.org/groups/1363/Research/contributions/hao-ryan-2008.pdf
4 *
5 * With hints from http://www.cl.cam.ac.uk/~fh240/software/JPAKE2.java.
6 */
7
8#ifndef HEADER_JPAKE_H
9# define HEADER_JPAKE_H
10
11# include <openssl/opensslconf.h>
12
13# ifdef OPENSSL_NO_JPAKE
14#  error JPAKE is disabled.
15# endif
16
17#ifdef  __cplusplus
18extern "C" {
19#endif
20
21# include <openssl/bn.h>
22# include <openssl/sha.h>
23
24typedef struct JPAKE_CTX JPAKE_CTX;
25
26/* Note that "g" in the ZKPs is not necessarily the J-PAKE g. */
27typedef struct {
28    BIGNUM *gr;                 /* g^r (r random) */
29    BIGNUM *b;                  /* b = r - x*h, h=hash(g, g^r, g^x, name) */
30} JPAKE_ZKP;
31
32typedef struct {
33    BIGNUM *gx;                 /* g^x in step 1, g^(xa + xc + xd) * xb * s
34                                 * in step 2 */
35    JPAKE_ZKP zkpx;             /* ZKP(x) or ZKP(xb * s) */
36} JPAKE_STEP_PART;
37
38typedef struct {
39    JPAKE_STEP_PART p1;         /* g^x3, ZKP(x3) or g^x1, ZKP(x1) */
40    JPAKE_STEP_PART p2;         /* g^x4, ZKP(x4) or g^x2, ZKP(x2) */
41} JPAKE_STEP1;
42
43typedef JPAKE_STEP_PART JPAKE_STEP2;
44
45typedef struct {
46    unsigned char hhk[SHA_DIGEST_LENGTH];
47} JPAKE_STEP3A;
48
49typedef struct {
50    unsigned char hk[SHA_DIGEST_LENGTH];
51} JPAKE_STEP3B;
52
53/* Parameters are copied */
54JPAKE_CTX *JPAKE_CTX_new(const char *name, const char *peer_name,
55                         const BIGNUM *p, const BIGNUM *g, const BIGNUM *q,
56                         const BIGNUM *secret);
57void JPAKE_CTX_free(JPAKE_CTX *ctx);
58
59/*
60 * Note that JPAKE_STEP1 can be used multiple times before release
61 * without another init.
62 */
63void JPAKE_STEP1_init(JPAKE_STEP1 *s1);
64int JPAKE_STEP1_generate(JPAKE_STEP1 *send, JPAKE_CTX *ctx);
65int JPAKE_STEP1_process(JPAKE_CTX *ctx, const JPAKE_STEP1 *received);
66void JPAKE_STEP1_release(JPAKE_STEP1 *s1);
67
68/*
69 * Note that JPAKE_STEP2 can be used multiple times before release
70 * without another init.
71 */
72void JPAKE_STEP2_init(JPAKE_STEP2 *s2);
73int JPAKE_STEP2_generate(JPAKE_STEP2 *send, JPAKE_CTX *ctx);
74int JPAKE_STEP2_process(JPAKE_CTX *ctx, const JPAKE_STEP2 *received);
75void JPAKE_STEP2_release(JPAKE_STEP2 *s2);
76
77/*
78 * Optionally verify the shared key. If the shared secrets do not
79 * match, the two ends will disagree about the shared key, but
80 * otherwise the protocol will succeed.
81 */
82void JPAKE_STEP3A_init(JPAKE_STEP3A *s3a);
83int JPAKE_STEP3A_generate(JPAKE_STEP3A *send, JPAKE_CTX *ctx);
84int JPAKE_STEP3A_process(JPAKE_CTX *ctx, const JPAKE_STEP3A *received);
85void JPAKE_STEP3A_release(JPAKE_STEP3A *s3a);
86
87void JPAKE_STEP3B_init(JPAKE_STEP3B *s3b);
88int JPAKE_STEP3B_generate(JPAKE_STEP3B *send, JPAKE_CTX *ctx);
89int JPAKE_STEP3B_process(JPAKE_CTX *ctx, const JPAKE_STEP3B *received);
90void JPAKE_STEP3B_release(JPAKE_STEP3B *s3b);
91
92/*
93 * the return value belongs to the library and will be released when
94 * ctx is released, and will change when a new handshake is performed.
95 */
96const BIGNUM *JPAKE_get_shared_key(JPAKE_CTX *ctx);
97
98/* BEGIN ERROR CODES */
99/*
100 * The following lines are auto generated by the script mkerr.pl. Any changes
101 * made after this point may be overwritten when the script is next run.
102 */
103void ERR_load_JPAKE_strings(void);
104
105/* Error codes for the JPAKE functions. */
106
107/* Function codes. */
108# define JPAKE_F_JPAKE_STEP1_PROCESS                      101
109# define JPAKE_F_JPAKE_STEP2_PROCESS                      102
110# define JPAKE_F_JPAKE_STEP3A_PROCESS                     103
111# define JPAKE_F_JPAKE_STEP3B_PROCESS                     104
112# define JPAKE_F_VERIFY_ZKP                               100
113
114/* Reason codes. */
115# define JPAKE_R_G_TO_THE_X3_IS_NOT_LEGAL                 108
116# define JPAKE_R_G_TO_THE_X4_IS_NOT_LEGAL                 109
117# define JPAKE_R_G_TO_THE_X4_IS_ONE                       105
118# define JPAKE_R_HASH_OF_HASH_OF_KEY_MISMATCH             106
119# define JPAKE_R_HASH_OF_KEY_MISMATCH                     107
120# define JPAKE_R_VERIFY_B_FAILED                          102
121# define JPAKE_R_VERIFY_X3_FAILED                         103
122# define JPAKE_R_VERIFY_X4_FAILED                         104
123# define JPAKE_R_ZKP_VERIFY_FAILED                        100
124
125#ifdef  __cplusplus
126}
127#endif
128#endif
129