static VALUE
ossl_x509ext_initialize(int argc, VALUE *argv, VALUE self)
{
    VALUE oid, value, critical;
    const unsigned char *p;
    X509_EXTENSION *ext, *x;

    GetX509Ext(self, ext);
    if(rb_scan_args(argc, argv, "12", &oid, &value, &critical) == 1){
        oid = ossl_to_der_if_possible(oid);
        StringValue(oid);
        p = (unsigned char *)RSTRING_PTR(oid);
        x = d2i_X509_EXTENSION(&ext, &p, RSTRING_LEN(oid));
        DATA_PTR(self) = ext;
        if(!x)
            ossl_raise(eX509ExtError, NULL);
        return self;
    }
    rb_funcall(self, rb_intern("oid="), 1, oid);
    rb_funcall(self, rb_intern("value="), 1, value);
    if(argc > 2) rb_funcall(self, rb_intern("critical="), 1, critical);

    return self;
}

# File ext/openssl/lib/openssl/x509.rb, line 48
def ==(other)
  return false unless Extension === other
  to_der == other.to_der
end

static VALUE
ossl_x509ext_set_critical(VALUE self, VALUE flag)
{
    X509_EXTENSION *ext;

    GetX509Ext(self, ext);
    X509_EXTENSION_set_critical(ext, RTEST(flag) ? 1 : 0);

    return flag;
}

static VALUE
ossl_x509ext_get_critical(VALUE obj)
{
    X509_EXTENSION *ext;

    GetX509Ext(obj, ext);
    return X509_EXTENSION_get_critical(ext) ? Qtrue : Qfalse;
}

static VALUE
ossl_x509ext_get_oid(VALUE obj)
{
    X509_EXTENSION *ext;

    GetX509Ext(obj, ext);
    return ossl_asn1obj_to_string(X509_EXTENSION_get_object(ext));
}

static VALUE
ossl_x509ext_set_oid(VALUE self, VALUE oid)
{
    X509_EXTENSION *ext;
    ASN1_OBJECT *obj;

    GetX509Ext(self, ext);
    obj = OBJ_txt2obj(StringValueCStr(oid), 0);
    if (!obj)
        ossl_raise(eX509ExtError, "OBJ_txt2obj");
    if (!X509_EXTENSION_set_object(ext, obj)) {
        ASN1_OBJECT_free(obj);
        ossl_raise(eX509ExtError, "X509_EXTENSION_set_object");
    }
    ASN1_OBJECT_free(obj);

    return oid;
}

# File ext/openssl/lib/openssl/x509.rb, line 64
def to_a
  [ self.oid, self.value, self.critical? ]
end

static VALUE
ossl_x509ext_to_der(VALUE obj)
{
    X509_EXTENSION *ext;
    unsigned char *p;
    long len;
    VALUE str;

    GetX509Ext(obj, ext);
    if((len = i2d_X509_EXTENSION(ext, NULL)) <= 0)
        ossl_raise(eX509ExtError, NULL);
    str = rb_str_new(0, len);
    p = (unsigned char *)RSTRING_PTR(str);
    if(i2d_X509_EXTENSION(ext, &p) < 0)
        ossl_raise(eX509ExtError, NULL);
    ossl_str_adjust(str, p);

    return str;
}

# File ext/openssl/lib/openssl/x509.rb, line 60
def to_h # {"oid"=>sn|ln, "value"=>value, "critical"=>true|false}
  {"oid"=>self.oid,"value"=>self.value,"critical"=>self.critical?}
end

# File ext/openssl/lib/openssl/x509.rb, line 53
def to_s # "oid = critical, value"
  str = self.oid
  str << " = "
  str << "critical, " if self.critical?
  str << self.value.gsub(/\n/, ", ")
end

static VALUE
ossl_x509ext_get_value(VALUE obj)
{
    X509_EXTENSION *ext;
    BIO *out;
    VALUE ret;

    GetX509Ext(obj, ext);
    if (!(out = BIO_new(BIO_s_mem())))
        ossl_raise(eX509ExtError, NULL);
    if (!X509V3_EXT_print(out, ext, 0, 0))
        ASN1_STRING_print(out, (ASN1_STRING *)X509_EXTENSION_get_data(ext));
    ret = ossl_membio2str(out);

    return ret;
}

static VALUE
ossl_x509ext_set_value(VALUE self, VALUE data)
{
    X509_EXTENSION *ext;
    ASN1_OCTET_STRING *asn1s;

    GetX509Ext(self, ext);
    data = ossl_to_der_if_possible(data);
    StringValue(data);
    asn1s = X509_EXTENSION_get_data(ext);

    if (!ASN1_OCTET_STRING_set(asn1s, (unsigned char *)RSTRING_PTR(data),
                               RSTRING_LENINT(data))) {
        ossl_raise(eX509ExtError, "ASN1_OCTET_STRING_set");
    }

    return data;
}

static VALUE
ossl_x509ext_get_value_der(VALUE obj)
{
    X509_EXTENSION *ext;
    ASN1_OCTET_STRING *value;

    GetX509Ext(obj, ext);
    if ((value = X509_EXTENSION_get_data(ext)) == NULL)
        ossl_raise(eX509ExtError, NULL);

    return asn1str_to_str(value);
}