crypto/jpake/jpake.h

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