Method: OpenSSL::PKey::DH#compute_key

Defined in:
ossl_pkey_dh.c

#compute_key(pub_bn) ⇒ aString

Returns a String containing a shared secret computed from the other party’s public value. See DH_compute_key() for further information.

Parameters

  • pub_bn is a OpenSSL::BN, not the DH instance returned by

DH#public_key as that contains the DH parameters only.

Returns:

  • (aString) 

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# File 'ossl_pkey_dh.c', line 532

static VALUE
ossl_dh_compute_key(VALUE self, VALUE pub)
{
    DH *dh;
    const BIGNUM *pub_key, *dh_p;
    VALUE str;
    int len;

    GetDH(self, dh);
    DH_get0_pqg(dh, &dh_p, NULL, NULL);
    if (!dh_p)
	ossl_raise(eDHError, "incomplete DH");
    pub_key = GetBNPtr(pub);
    len = DH_size(dh);
    str = rb_str_new(0, len);
    if ((len = DH_compute_key((unsigned char *)RSTRING_PTR(str), pub_key, dh)) < 0) {
	ossl_raise(eDHError, NULL);
    }
    rb_str_set_len(str, len);

    return str;
}