includes/clientside/static/diffiehellman.js
changeset 436 242353360e37
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435:a434d60e525d 436:242353360e37
       
     1 /*
       
     2  * The Diffie-Hellman key exchange protocol.
       
     3  */
       
     4 
       
     5 // Our prime number as a base for operations.
       
     6 var dh_prime = '82818079787776757473727170696867666564636261605958575655545352515049484746454443424140393837363534333231302928272625242322212019181716151413121110987654321';
       
     7 
       
     8 // g, a primitive root used as an exponent
       
     9 // (2 and 5 are acceptable, but BigInt is faster with odd numbers)
       
    10 var dh_g = '5';
       
    11 
       
    12 /**
       
    13  * Generates a Diffie-Hellman private key
       
    14  * @return string(BigInt)
       
    15  */
       
    16 
       
    17 function dh_gen_private()
       
    18 {
       
    19   return EnanoMath.RandomInt(256);
       
    20 }
       
    21 
       
    22 /**
       
    23  * Calculates the public key from the private key
       
    24  * @param string(BigInt)
       
    25  * @return string(BigInt)
       
    26  */
       
    27 
       
    28 function dh_gen_public(b)
       
    29 {
       
    30   return EnanoMath.PowMod(dh_g, b, dh_prime);
       
    31 }
       
    32 
       
    33 /**
       
    34  * Calculates the shared secret.
       
    35  * @param string(BigInt) Our private key
       
    36  * @param string(BigInt) Remote party's public key
       
    37  * @return string(BigInt)
       
    38  */
       
    39 
       
    40 function dh_gen_shared_secret(b, A)
       
    41 {
       
    42   return EnanoMath.PowMod(A, b, dh_prime);
       
    43 }
       
    44