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      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
     18 extern "C" {
     19 #endif
     20 
     21 #include <openssl/bn.h>
     22 #include <openssl/sha.h>
     23 
     24 typedef struct JPAKE_CTX JPAKE_CTX;
     25 
     26 /* Note that "g" in the ZKPs is not necessarily the J-PAKE g. */
     27 typedef struct
     28     {
     29     BIGNUM *gr; /* g^r (r random) */
     30     BIGNUM *b;  /* b = r - x*h, h=hash(g, g^r, g^x, name) */
     31     } JPAKE_ZKP;
     32 
     33 typedef struct
     34     {
     35     BIGNUM *gx;       /* g^x in step 1, g^(xa + xc + xd) * xb * s in step 2 */
     36     JPAKE_ZKP zkpx;   /* ZKP(x) or ZKP(xb * s) */
     37     } JPAKE_STEP_PART;
     38 
     39 typedef struct
     40     {
     41     JPAKE_STEP_PART p1;   /* g^x3, ZKP(x3) or g^x1, ZKP(x1) */
     42     JPAKE_STEP_PART p2;   /* g^x4, ZKP(x4) or g^x2, ZKP(x2) */
     43     } JPAKE_STEP1;
     44 
     45 typedef JPAKE_STEP_PART JPAKE_STEP2;
     46 
     47 typedef struct
     48     {
     49     unsigned char hhk[SHA_DIGEST_LENGTH];
     50     } JPAKE_STEP3A;
     51 
     52 typedef struct
     53     {
     54     unsigned char hk[SHA_DIGEST_LENGTH];
     55     } JPAKE_STEP3B;
     56 
     57 /* Parameters are copied */
     58 JPAKE_CTX *JPAKE_CTX_new(const char *name, const char *peer_name,
     59 			 const BIGNUM *p, const BIGNUM *g, const BIGNUM *q,
     60 			 const BIGNUM *secret);
     61 void JPAKE_CTX_free(JPAKE_CTX *ctx);
     62 
     63 /*
     64  * Note that JPAKE_STEP1 can be used multiple times before release
     65  * without another init.
     66  */
     67 void JPAKE_STEP1_init(JPAKE_STEP1 *s1);
     68 int JPAKE_STEP1_generate(JPAKE_STEP1 *send, JPAKE_CTX *ctx);
     69 int JPAKE_STEP1_process(JPAKE_CTX *ctx, const JPAKE_STEP1 *received);
     70 void JPAKE_STEP1_release(JPAKE_STEP1 *s1);
     71 
     72 /*
     73  * Note that JPAKE_STEP2 can be used multiple times before release
     74  * without another init.
     75  */
     76 void JPAKE_STEP2_init(JPAKE_STEP2 *s2);
     77 int JPAKE_STEP2_generate(JPAKE_STEP2 *send, JPAKE_CTX *ctx);
     78 int JPAKE_STEP2_process(JPAKE_CTX *ctx, const JPAKE_STEP2 *received);
     79 void JPAKE_STEP2_release(JPAKE_STEP2 *s2);
     80 
     81 /*
     82  * Optionally verify the shared key. If the shared secrets do not
     83  * match, the two ends will disagree about the shared key, but
     84  * otherwise the protocol will succeed.
     85  */
     86 void JPAKE_STEP3A_init(JPAKE_STEP3A *s3a);
     87 int JPAKE_STEP3A_generate(JPAKE_STEP3A *send, JPAKE_CTX *ctx);
     88 int JPAKE_STEP3A_process(JPAKE_CTX *ctx, const JPAKE_STEP3A *received);
     89 void JPAKE_STEP3A_release(JPAKE_STEP3A *s3a);
     90 
     91 void JPAKE_STEP3B_init(JPAKE_STEP3B *s3b);
     92 int JPAKE_STEP3B_generate(JPAKE_STEP3B *send, JPAKE_CTX *ctx);
     93 int JPAKE_STEP3B_process(JPAKE_CTX *ctx, const JPAKE_STEP3B *received);
     94 void JPAKE_STEP3B_release(JPAKE_STEP3B *s3b);
     95 
     96 /*
     97  * the return value belongs to the library and will be released when
     98  * ctx is released, and will change when a new handshake is performed.
     99  */
    100 const BIGNUM *JPAKE_get_shared_key(JPAKE_CTX *ctx);
    101 
    102 /* BEGIN ERROR CODES */
    103 /* The following lines are auto generated by the script mkerr.pl. Any changes
    104  * made after this point may be overwritten when the script is next run.
    105  */
    106 void ERR_load_JPAKE_strings(void);
    107 
    108 /* Error codes for the JPAKE functions. */
    109 
    110 /* Function codes. */
    111 #define JPAKE_F_JPAKE_STEP1_PROCESS			 101
    112 #define JPAKE_F_JPAKE_STEP2_PROCESS			 102
    113 #define JPAKE_F_JPAKE_STEP3A_PROCESS			 103
    114 #define JPAKE_F_JPAKE_STEP3B_PROCESS			 104
    115 #define JPAKE_F_VERIFY_ZKP				 100
    116 
    117 /* Reason codes. */
    118 #define JPAKE_R_G_TO_THE_X3_IS_NOT_LEGAL		 108
    119 #define JPAKE_R_G_TO_THE_X4_IS_NOT_LEGAL		 109
    120 #define JPAKE_R_G_TO_THE_X4_IS_ONE			 105
    121 #define JPAKE_R_HASH_OF_HASH_OF_KEY_MISMATCH		 106
    122 #define JPAKE_R_HASH_OF_KEY_MISMATCH			 107
    123 #define JPAKE_R_VERIFY_B_FAILED				 102
    124 #define JPAKE_R_VERIFY_X3_FAILED			 103
    125 #define JPAKE_R_VERIFY_X4_FAILED			 104
    126 #define JPAKE_R_ZKP_VERIFY_FAILED			 100
    127 
    128 #ifdef  __cplusplus
    129 }
    130 #endif
    131 #endif
    132