DHgeneratekey(3) OpenSSL DHgeneratekey(3)

NAME
       DHgeneratekey, DHcomputekey - perform Diffie-Hellman key exchange

SYNOPSIS
        #include 

        int DHgeneratekey(DH *dh);

        int DHcomputekey(unsigned char *key, BIGNUM *pubkey, DH *dh);

DESCRIPTION
       DHgeneratekey() performs the first step of a Diffie-Hellman key
       exchange by generating private and public DH values. By calling
       DHcomputekey(), these are combined with the other party's public
       value to compute the shared key.

       DHgeneratekey() expects ddhh to contain the shared parameters ddhh->>pp and
       ddhh->>gg. It generates a random private DH value unless ddhh->>pprriivvkkeeyy is
       already set, and computes the corresponding public value ddhh->>ppuubbkkeeyy,
       which can then be published.

       DHcomputekey() computes the shared secret from the private DH value
       in ddhh and the other party's public value in ppuubbkkeeyy and stores it in
       kkeeyy. kkeeyy must point to DDHHssiizzee((ddhh)) bytes of memory.

RETURN VALUES
       DHgeneratekey() returns 1 on success, 0 otherwise.

       DHcomputekey() returns the size of the shared secret on success, -1
       on error.

       The error codes can be obtained by ERRgeterror(3).

SEE ALSO
       dh(3), ERRgeterror(3), rand(3), DHsize(3)

HISTORY       DHgeneratekey() and DHcomputekey() are available in all versions of
       SSLeay and OpenSSL.



0.9.7l                            2002-09-25                DHgeneratekey(3)