Method: OpenSSL::PKey::DH#initialize

Defined in:
ossl_pkey_dh.c

#newObject #new(string) ⇒ Object #new(size[, generator]) ⇒ Object

Creates a new instance of OpenSSL::PKey::DH.

If called without arguments, an empty instance without any parameter or key components is created. Use #set_pqg to manually set the parameters afterwards (and optionally #set_key to set private and public key components).

If a String is given, tries to parse it as a DER- or PEM- encoded parameters. See also OpenSSL::PKey.read which can parse keys of any kinds.

The DH.new(size [, generator]) form is an alias of DH.generate.

string

A String that contains the DER or PEM encoded key.

size

See DH.generate.

generator

See DH.generate.

Examples:

# Creating an instance from scratch
# Note that this is deprecated and will not work on OpenSSL 3.0 or later.
dh = OpenSSL::PKey::DH.new
dh.set_pqg(bn_p, nil, bn_g)

# Generating a parameters and a key pair
dh = OpenSSL::PKey::DH.new(2048) # An alias of OpenSSL::PKey::DH.generate(2048)

# Reading DH parameters
dh_params = OpenSSL::PKey::DH.new(File.read('parameters.pem')) # loads parameters only
dh = OpenSSL::PKey.generate_key(dh_params) # generates a key pair

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# File 'ossl_pkey_dh.c', line 72

static VALUE
ossl_dh_initialize(int argc, VALUE *argv, VALUE self)
{
    EVP_PKEY *pkey;
    int type;
    DH *dh;
    BIO *in = NULL;
    VALUE arg;

    TypedData_Get_Struct(self, EVP_PKEY, &ossl_evp_pkey_type, pkey);
    if (pkey)
        rb_raise(rb_eTypeError, "pkey already initialized");

    /* The DH.new(size, generator) form is handled by lib/openssl/pkey.rb */
    if (rb_scan_args(argc, argv, "01", &arg) == 0) {
        dh = DH_new();
        if (!dh)
            ossl_raise(eDHError, "DH_new");
        goto legacy;
    }

    arg = ossl_to_der_if_possible(arg);
    in = ossl_obj2bio(&arg);

    /*
     * On OpenSSL <= 1.1.1 and current versions of LibreSSL, the generic
     * routine does not support DER-encoded parameters
     */
    dh = d2i_DHparams_bio(in, NULL);
    if (dh)
        goto legacy;
    OSSL_BIO_reset(in);

    pkey = ossl_pkey_read_generic(in, Qnil);
    BIO_free(in);
    if (!pkey)
        ossl_raise(eDHError, "could not parse pkey");

    type = EVP_PKEY_base_id(pkey);
    if (type != EVP_PKEY_DH) {
        EVP_PKEY_free(pkey);
        rb_raise(eDHError, "incorrect pkey type: %s", OBJ_nid2sn(type));
    }
    RTYPEDDATA_DATA(self) = pkey;
    return self;

  legacy:
    BIO_free(in);
    pkey = EVP_PKEY_new();
    if (!pkey || EVP_PKEY_assign_DH(pkey, dh) != 1) {
        EVP_PKEY_free(pkey);
        DH_free(dh);
        ossl_raise(eDHError, "EVP_PKEY_assign_DH");
    }
    RTYPEDDATA_DATA(self) = pkey;
    return self;
}