base.c

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/*
 *   This library is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU Lesser General Public
 *   License as published by the Free Software Foundation; either
 *   version 2.1 of the License, or (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *   Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: b40d355d46838505f4beb6adcc88a8a79400ce97 $
 *
 * @file protocols/der/decode.c
 * @brief Functions to decode DER encoded data.
 *
 * @author Ethan Thompson (ethan.thompson@inkbridge.io)
 *
 * @copyright (C) 2025 Network RADIUS SAS (legal@networkradius.com)
 */
RCSID("$Id: b40d355d46838505f4beb6adcc88a8a79400ce97 $")
 
#include <freeradius-devel/util/net.h>
#include <freeradius-devel/util/proto.h>
#include <freeradius-devel/util/table.h>
#include <freeradius-devel/util/dict_ext_priv.h>
 
#include "attrs.h"
#include "der.h"
 
static uint32_t instance_count = 0;
 
fr_dict_t const *dict_der;
fr_dict_attr_t const *attr_oid_tree;
 
extern fr_dict_autoload_t libfreeradius_der_dict[];
fr_dict_autoload_t        libfreeradius_der_dict[] = {
        { .out = &dict_der, .proto = "der" },
 
        DICT_AUTOLOAD_TERMINATOR
};
 
extern fr_dict_attr_autoload_t libfreeradius_der_dict_attr[];
fr_dict_attr_autoload_t        libfreeradius_der_dict_attr[] = {
        { .out = &attr_oid_tree, .name = "OID-Tree", .type = FR_TYPE_TLV, .dict = &dict_der },
        DICT_AUTOLOAD_TERMINATOR
};
 
static fr_table_num_sorted_t const tag_name_to_number[] = {
        { L("bitstring"),               FR_DER_TAG_BITSTRING },
        { L("bmpstring"),               FR_DER_TAG_BMP_STRING },
        { L("boolean"),                 FR_DER_TAG_BOOLEAN },
        { L("choice"),                  FR_DER_TAG_CHOICE },
        { L("enumerated"),              FR_DER_TAG_ENUMERATED },
        { L("generalizedtime"),         FR_DER_TAG_GENERALIZED_TIME },
        { L("generalstring"),           FR_DER_TAG_GENERAL_STRING },
        { L("ia5string"),               FR_DER_TAG_IA5_STRING },
        { L("integer"),                 FR_DER_TAG_INTEGER },
        { L("null"),                    FR_DER_TAG_NULL },
        { L("octetstring"),             FR_DER_TAG_OCTETSTRING },
        { L("oid"),                     FR_DER_TAG_OID },
        { L("printablestring"),         FR_DER_TAG_PRINTABLE_STRING },
        { L("sequence"),                FR_DER_TAG_SEQUENCE },
        { L("set"),                     FR_DER_TAG_SET },
        { L("t61string"),               FR_DER_TAG_T61_STRING },
        { L("universalstring"),         FR_DER_TAG_UNIVERSAL_STRING },
        { L("utctime"),                 FR_DER_TAG_UTC_TIME },
        { L("utf8string"),              FR_DER_TAG_UTF8_STRING },
        { L("visiblestring"),           FR_DER_TAG_VISIBLE_STRING },
};
static size_t tag_name_to_number_len = NUM_ELEMENTS(tag_name_to_number);
 
 
char const *fr_der_tag_to_str(fr_der_tag_t tag)
{
        return fr_table_str_by_value(tag_name_to_number, tag, "???");
}
 
#define ALL_STRINGS ((1 << FR_DER_TAG_BMP_STRING) | (1 << FR_DER_TAG_GENERAL_STRING) | \
                     (1 << FR_DER_TAG_IA5_STRING) | (1 << FR_DER_TAG_PRINTABLE_STRING) | \
                     (1 << FR_DER_TAG_T61_STRING) | (1 << FR_DER_TAG_UTF8_STRING) | \
                     (1 << FR_DER_TAG_VISIBLE_STRING))
 
static const uint64_t der_tags_compatible[FR_DER_TAG_MAX] = {
        [FR_DER_TAG_UTC_TIME] = (1 << FR_DER_TAG_GENERALIZED_TIME),
        [FR_DER_TAG_GENERALIZED_TIME] = (1 << FR_DER_TAG_UTC_TIME),
 
        [FR_DER_TAG_BMP_STRING] = ALL_STRINGS,
        [FR_DER_TAG_GENERAL_STRING] = ALL_STRINGS,
        [FR_DER_TAG_IA5_STRING] = ALL_STRINGS,
        [FR_DER_TAG_PRINTABLE_STRING] = ALL_STRINGS,
        [FR_DER_TAG_T61_STRING] = ALL_STRINGS,
        [FR_DER_TAG_UTF8_STRING] = ALL_STRINGS,
        [FR_DER_TAG_VISIBLE_STRING] = ALL_STRINGS,
};
 
bool fr_der_tags_compatible(fr_der_tag_t tag1, fr_der_tag_t tag2)
{
        return (der_tags_compatible[tag1] & (1 << (uint64_t) tag2)) != 0;
}
 
/*
 *      Create a mapping between FR_TYPE_* and valid FR_DER_TAG_*'s
 */
static const bool *fr_type_to_der_tags[FR_DER_TAG_MAX] = {
        [FR_TYPE_IPV4_ADDR] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_BITSTRING] = true,
        },
 
        [FR_TYPE_IPV4_PREFIX] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_BITSTRING] = true,
        },
 
        [FR_TYPE_IPV6_ADDR] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_BITSTRING] = true,
        },
 
        [FR_TYPE_IPV6_PREFIX] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_BITSTRING] = true,
        },
 
        [FR_TYPE_COMBO_IP_ADDR] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_OCTETSTRING] = true,
        },
 
        [FR_TYPE_BOOL] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_BOOLEAN] = true,
                [FR_DER_TAG_INTEGER] = true,
                [FR_DER_TAG_NULL] = true,
        },
        [FR_TYPE_INT64] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_INTEGER] = true,
                [FR_DER_TAG_ENUMERATED] = true,
        },
        [FR_TYPE_OCTETS] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_BITSTRING] = true,
                [FR_DER_TAG_OCTETSTRING] = true,
        },
        [FR_TYPE_STRING] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_UTF8_STRING] = true,
                [FR_DER_TAG_PRINTABLE_STRING] = true,
                [FR_DER_TAG_T61_STRING] = true,
                [FR_DER_TAG_IA5_STRING] = true,
                [FR_DER_TAG_VISIBLE_STRING] = true,
                [FR_DER_TAG_GENERAL_STRING] = true,
                [FR_DER_TAG_UNIVERSAL_STRING] = true,
        },
        [FR_TYPE_DATE] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_UTC_TIME] = true,
                [FR_DER_TAG_GENERALIZED_TIME] = true,
        },
        [FR_TYPE_ATTR] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_OID] = true,
        },
        [FR_TYPE_TLV] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_SEQUENCE] = true,
                [FR_DER_TAG_SET] = true,
        },
        [FR_TYPE_STRUCT] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_BITSTRING] = true,
        },
        [FR_TYPE_GROUP] = (bool [FR_DER_TAG_MAX]) {
                [FR_DER_TAG_SEQUENCE] = true,
        },
};
 
/*
 *      Return true if the given type can be encoded as the given tag.
 *              @param[in] type The fr_type to check.
 *              @param[in] tag The der tag to check.
 *              @return true if the type can be encoded as the given tag.
 */
bool fr_type_to_der_tag_valid(fr_type_t type, fr_der_tag_t tag)
{
        if (!fr_type_to_der_tags[type]) return false;
 
        return fr_type_to_der_tags[type][tag];
}
 
 
int fr_der_global_init(void)
{
        if (instance_count > 0) {
                instance_count++;
                return 0;
        }
 
        instance_count++;
 
        if (fr_dict_autoload(libfreeradius_der_dict) < 0) {
        fail:
                instance_count--;
                return -1;
        }
 
        if (fr_dict_attr_autoload(libfreeradius_der_dict_attr) < 0) {
                fr_dict_autofree(libfreeradius_der_dict);
                goto fail;
        }
 
        return 0;
}
 
void fr_der_global_free(void)
{
        if (--instance_count != 0) return;
 
        fr_dict_autofree(libfreeradius_der_dict);
}
 
/*
 *      Allow setting class of APPLICATION and PRIVATE.
 */
static int dict_flag_class(fr_dict_attr_t **da_p, char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        static const fr_table_num_sorted_t table[] = {
                { L("application"),     FR_DER_CLASS_APPLICATION },
                { L("private"),         FR_DER_CLASS_PRIVATE },
        };
        static size_t table_len = NUM_ELEMENTS(table);
 
        fr_der_attr_flags_t *flags;
        fr_der_tag_class_t   tag_class;
 
        flags = fr_dict_attr_ext((*da_p)->parent, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        if (flags->der_type != FR_DER_TAG_SEQUENCE) {
                fr_strerror_printf("Cannot use 'class' for attribute %s DER type %s - the parent must be 'sequence'",
                                   (*da_p)->parent->name, fr_der_tag_to_str(flags->der_type));
                return -1;
        }
 
        if ((*da_p)->attr >= FR_DER_TAG_VALUE_MAX) {
                fr_strerror_printf("Cannot use 'class' for attribute %s - the attribute number must be 0..30",
                                   (*da_p)->parent->name);
                return -1;
        }
 
        flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        if (flags->class) {
                fr_strerror_printf("Attribute %s already has a 'class' defined", (*da_p)->name);
                return -1;
        }
 
        tag_class = fr_table_value_by_str(table, value, FR_DER_CLASS_INVALID);
        if (tag_class == FR_DER_CLASS_INVALID) {
                fr_strerror_printf("Unknown or invalid name in 'class=%s'", value);
                return -1;
        }
 
        flags->class = tag_class;
 
        return 0;
}
 
static int dict_flag_default_value(fr_dict_attr_t **da_p, char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
 
        if (!fr_type_is_leaf((*da_p)->type)) {
                fr_strerror_printf("Cannot set 'default=...' for attribute %s DER type %s",
                                   (*da_p)->name, fr_der_tag_to_str(flags->der_type));
                return -1;
        }
 
        /*
         *      The default values are parented from the dict root.  That way we don't need to copy the values
         *      when we clone the attribute, we can just copy the pointer.
         */
        flags->default_value = fr_value_box_alloc(fr_dict_unconst((*da_p)->dict), (*da_p)->type, NULL);
        if (!flags->default_value) return -1;
 
        if (fr_value_box_from_str(flags->default_value, flags->default_value, (*da_p)->type, NULL,
                                  value, strlen(value), NULL) < 0) {
                fr_strerror_printf("Failed parsing 'value=...' - %s", fr_strerror());
                return -1;
        }
 
        flags->has_default_value = true;
 
        return 0;
}
 
static int dict_flag_der_type(fr_dict_attr_t **da_p, char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        fr_der_tag_t     der_type;
 
        der_type = fr_table_value_by_str(tag_name_to_number, value, FR_DER_TAG_INVALID);
        if (der_type == FR_DER_TAG_INVALID) {
                fr_strerror_printf("Unknown type in 'der_type=%s'", value);
                return -1;
        }
 
        /*
         *      The DER type and FreeRADIUS type must be compatible.
         *
         *      Except for some der_type=integer, such as a
         *      certificate serialNumber.  Those are too large for us
         *      to represent in 64 bits, so we just treat them as
         *      'octets'.
         */
        if (!fr_type_to_der_tag_valid((*da_p)->type, der_type) &&
            (der_type != FR_DER_TAG_INTEGER) && ((*da_p)->type != FR_TYPE_OCTETS)) {
                fr_strerror_printf("Attribute type %s is not compatible with 'der_type=%s'",
                                   fr_type_to_str((*da_p)->type), value);
                return -1;
        }
 
        flags->der_type = der_type;
 
        return 0;
}
 
static int dict_flag_set_oid_and_value(fr_dict_attr_t **da_p, fr_der_attr_flags_t *flags)
{
        flags->is_oid_and_value = true;
        flags->is_sequence_of = true;
        flags->sequence_of = FR_DER_TAG_SEQUENCE;
 
        /*
         *      The dict autoload things aren't set until after we load all of the dictionary entries.  So we
         *      just manually set it here for laziness.
         */
        if (!attr_oid_tree) {
                attr_oid_tree = fr_dict_attr_by_name(NULL, fr_dict_root((*da_p)->dict), "OID-Tree");
                if (!attr_oid_tree) return -1;
        }
 
        if (fr_dict_attr_set_group(da_p, attr_oid_tree) < 0) return -1;
 
        (*da_p)->flags.allow_flat = true;
        return 0;
}
 
static int dict_flag_sequence_of(fr_dict_attr_t **da_p, char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        fr_der_tag_t     type;
 
        if (flags->is_set_of) {
                fr_strerror_const("Cannot be both 'sequence_of=...' and 'set_of=...'");
                return -1;
        }
 
        if (flags->der_type != FR_DER_TAG_SEQUENCE) {
                fr_strerror_printf("Cannot use 'sequence_of=...' for DER type '%s'", fr_der_tag_to_str(flags->der_type));
                return -1;
        }
 
        if (strcmp(value, "oid_and_value") == 0) {
                return dict_flag_set_oid_and_value(da_p, flags);
        }
 
        type = fr_table_value_by_str(tag_name_to_number, value, FR_DER_TAG_INVALID);
        if (type == FR_DER_TAG_INVALID) {
                fr_strerror_printf("Unknown type in 'sequence_of=%s'", value);
                return -1;
        }
 
        flags->sequence_of = type;
        flags->is_sequence_of = true;
 
        return 0;
}
 
static int dict_flag_set_of(fr_dict_attr_t **da_p, char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        fr_der_tag_t     type;
 
        if (flags->is_sequence_of) {
                fr_strerror_const("Cannot be both 'sequence_of=...' and 'set_of=...'");
                return -1;
        }
 
        if (flags->der_type != FR_DER_TAG_SET) {
                fr_strerror_printf("Cannot use 'set_of=...' for DER type '%s'", fr_der_tag_to_str(flags->der_type));
                return -1;
        }
 
        if (strcmp(value, "oid_and_value") == 0) {
                return dict_flag_set_oid_and_value(da_p, flags);
        }
 
        type = fr_table_value_by_str(tag_name_to_number, value, FR_DER_TAG_INVALID);
        if (type == FR_DER_TAG_INVALID) {
                fr_strerror_printf("Unknown type in 'set_of=%s'", value);
                return -1;
        }
 
        /*
         *      The "choice" can only be used for sequence.
         */
        if (type == FR_DER_TAG_CHOICE) {
                fr_strerror_printf("Invalid type in 'set_of=%s' - 'choice' can only be used for sequences", value);
                return -1;
        }
 
        flags->set_of = type;
        flags->is_set_of = true;
 
        return 0;
}
 
static int dict_flag_is_extensions(fr_dict_attr_t **da_p, UNUSED char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
 
        flags->is_extensions = true;
 
        return 0;
}
 
static int dict_flag_leaf(fr_dict_attr_t **da_p, UNUSED char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
 
        /*
         *      The "leaf" property means that when we're encoding a nested set of attributes, we encode the
         *      OIDs until we hit one which has the "leaf" property set.  We then encode the OID of this
         *      attribute, along with its value.
         */
        if (fr_der_flag_der_type((*da_p)->parent) != FR_DER_TAG_SEQUENCE) {
                fr_strerror_printf("Cannot set 'leaf' for parent %s of DER type %s",
                                   (*da_p)->parent->name, fr_der_tag_to_str(fr_der_flag_der_type((*da_p)->parent)));
                return -1;
        }
 
        flags->leaf = true;
 
        return 0;
}
 
/*
 *      size=MIN..MAX
 */
static int dict_flag_size(fr_dict_attr_t **da_p, char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        unsigned long num;
        char const *p = value;
        char *end = NULL;
 
        if (fr_type_is_leaf((*da_p)->type) && !fr_type_is_variable_size((*da_p)->type)) {
                fr_strerror_printf("Cannot use 'size=...' for type '%s'", fr_type_to_str((*da_p)->type));
                return -1;
        }
 
        /*
         *      size=..max
         */
        if ((p[0] == '.') && (p[1] == '.')) goto check_max;
 
        num = strtoul(p, &end, 10);
        if (num == ULONG_MAX) {
        invalid:
                fr_strerror_printf("Invalid value in 'size=%s'", value);
                return -1;
        }
 
        if (num > UINT8_MAX) {
                fr_strerror_printf("Invalid value in 'size=%s' - 'min' value is too large", value);
                return -1;
        }
 
        /*
         *      size=4
         *
         *      Fixed size, but not size=0.
         */
        if (!*end) {
                if (!num) goto invalid;
 
                /*
                 *      printablestring size=2
                 *
                 *      instead of string[2] der_type=printablestring
                 */
                if (((*da_p)->type == FR_TYPE_OCTETS) || ((*da_p)->type == FR_TYPE_STRING)) {
                        (*da_p)->flags.is_known_width = !fr_type_is_structural((*da_p)->type);
                        (*da_p)->flags.length = num;
                        return 0;
                }
 
                /*
                 *      Sets and sequences can have a fixed number of elements.
                 */
                flags->min = flags->max = num;
                return 0;
        }
 
        if ((end[0] != '.') || (end[1] != '.')) {
                fr_strerror_printf("Invalid value in 'size=%s' - unexpected data after 'min'", value);
                return -1;
        }
 
        flags->min = num;
 
        /*
         *      size=1..
         *
         *      Sets the minimum, but not the maximum.
         */
        p = end + 2;
        if (!*p) return 0;
 
check_max:
        num = strtoul(p, &end, 10);
        if (num == ULONG_MAX) goto invalid;
 
        if (*end) {
                fr_strerror_printf("Invalid value in 'size=%s' - unexpected data after 'max'", value);
                return -1;
        }
 
        flags->max = num;
 
        return 0;
}
 
static int dict_flag_max(fr_dict_attr_t **da_p, char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        unsigned long num;
        char *end = NULL;
 
        num = strtoul(value, &end, 10);
        if (*end || !num || (num == ULONG_MAX)) {
                fr_strerror_printf("Invalid value in 'max=%s'", value);
                return -1;
        }
 
        flags->max = num;
 
        return 0;
}
 
static int dict_flag_option(fr_dict_attr_t **da_p, char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags;
        unsigned long num;
        char *end = NULL;
 
        /*
         *      Only SET and SEQUENCE can have tagged types.
         */
        flags = fr_dict_attr_ext((*da_p)->parent, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        if (!(*da_p)->parent->flags.is_root &&
            (flags->der_type != FR_DER_TAG_SEQUENCE) && (flags->der_type != FR_DER_TAG_SET)) {
                fr_strerror_printf("Cannot use 'option' for attribute %s DER type %s - the parent must be 'sequence' or 'set'",
                                   (*da_p)->parent->name, fr_der_tag_to_str(flags->der_type));
                return -1;
        }
 
        /*
         *      In the interest of laziness, allow a bare 'option', so
         *      that we don't have to give an attribute number, and
         *      then also duplicate that number in 'option='.
         */
        if (!value) {
                if (!(*da_p)->state.attr_set || (*da_p)->attr > 0x1f) {
                        fr_strerror_printf("Missing value for 'option='");
                        return -1;
                }
 
                num = (*da_p)->attr;
                goto check;
        }
 
        /*
         *      ATTRIBUTE can't have 'option='.
         */
        if ((*da_p)->state.attr_set) {
                fr_strerror_printf("Cannot use 'option=%s' for attribute %s, just use 'option'", value, (*da_p)->name);
                return -1;
        }
 
        /*
         *      We limit the allowed options (tag numbers) to ones
         *      which fit into the 5 bits of the first byte.  We don't
         *      support continued tags.
         */
        num = strtoul(value, &end, 10);
        if ((num == ULONG_MAX) || *end) {
                fr_strerror_printf("Invalid value in 'option=%s'", value);
                return -1;
        }
 
check:
        if (num >= FR_DER_TAG_VALUE_MAX) {
                fr_strerror_printf("Option value '%lu' is larger than 30", num);
                return -1;
        }
 
        flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        flags->class = FR_DER_CLASS_CONTEXT;
        flags->option = num;
        flags->is_option = true;
 
        return 0;
}
 
static int dict_flag_optional(fr_dict_attr_t **da_p, UNUSED char const *value, UNUSED fr_dict_flag_parser_rule_t const *rules)
{
        fr_der_attr_flags_t *flags;
 
        /*
         *      Only SET and SEQUENCE can have optional elements.
         */
        flags = fr_dict_attr_ext((*da_p)->parent, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        if (!(*da_p)->parent->flags.is_root &&
            (flags->der_type != FR_DER_TAG_SEQUENCE) && (flags->der_type != FR_DER_TAG_SET)) {
                fr_strerror_printf("Cannot use 'optional' for attribute %s DER type %s - the parent must be 'sequence' or 'set'",
                                   (*da_p)->parent->name, fr_der_tag_to_str(flags->der_type));
                return -1;
        }
 
        flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        flags->optional = true;
 
        return 0;
}
 
static const fr_dict_flag_parser_t  der_flags[] = {
        { L("class"),           { .func = dict_flag_class } },
        { L("default"),         { .func = dict_flag_default_value,.needs_value = true } },
        { L("der_type"),        { .func = dict_flag_der_type, .needs_value = true } },
        { L("is_extensions"),   { .func = dict_flag_is_extensions } },
        { L("leaf"),            { .func = dict_flag_leaf } },
        { L("max"),             { .func = dict_flag_max, .needs_value = true } },
        { L("option"),          { .func = dict_flag_option} },
        { L("optional"),        { .func = dict_flag_optional} },
        { L("sequence_of"),     { .func = dict_flag_sequence_of, .needs_value = true } },
        { L("set_of"),          { .func = dict_flag_set_of, .needs_value = true } },
        { L("size"),            { .func = dict_flag_size, .needs_value=true } },
};
 
static bool type_parse(fr_type_t *type_p,fr_dict_attr_t **da_p, char const *name)
{
        static const fr_table_num_sorted_t type_table[] = {
                { L("bitstring"),       FR_TYPE_OCTETS },
//              { L("bmpstring"),       FR_TYPE_OCTETS },
                { L("boolean"),         FR_TYPE_BOOL },
                { L("choice"),          FR_TYPE_TLV },
                { L("enumerated"),      FR_TYPE_INT64 },
                { L("generalizedtime"), FR_TYPE_DATE },
                { L("generalstring"),   FR_TYPE_STRING },
                { L("ia5string"),       FR_TYPE_STRING },
                { L("integer"),         FR_TYPE_INT64 },
                { L("null"),            FR_TYPE_BOOL },
                { L("octetstring"),     FR_TYPE_OCTETS },
                { L("oid"),             FR_TYPE_ATTR },
                { L("printablestring"), FR_TYPE_STRING },
                { L("sequence"),        FR_TYPE_TLV },
                { L("set"),             FR_TYPE_TLV },
                { L("t61string"),       FR_TYPE_STRING },
                { L("universalstring"), FR_TYPE_STRING },
                { L("utctime"),         FR_TYPE_DATE },
                { L("utf8string"),      FR_TYPE_STRING },
                { L("visiblestring"),   FR_TYPE_STRING },
                { L("x509_extensions"), FR_TYPE_GROUP }
        };
        static size_t type_table_len = NUM_ELEMENTS(type_table);
 
        static const fr_table_num_sorted_t der_tag_table[] = {
                { L("bitstring"),       FR_DER_TAG_BITSTRING },
//              { L("bmpstring"),       FR_DER_TAG_BMP_STRING },
                { L("boolean"),         FR_DER_TAG_BOOLEAN },
                { L("choice"),          FR_DER_TAG_SEQUENCE },
                { L("enumerated"),      FR_DER_TAG_ENUMERATED },
                { L("generalizedtime"), FR_DER_TAG_GENERALIZED_TIME },
                { L("generalstring"),   FR_DER_TAG_GENERAL_STRING },
                { L("ia5string"),       FR_DER_TAG_IA5_STRING },
                { L("integer"),         FR_DER_TAG_INTEGER },
                { L("null"),            FR_DER_TAG_NULL },
                { L("octetstring"),     FR_DER_TAG_OCTETSTRING },
                { L("oid"),             FR_DER_TAG_OID },
                { L("printablestring"), FR_DER_TAG_PRINTABLE_STRING },
                { L("sequence"),        FR_DER_TAG_SEQUENCE },
                { L("set"),             FR_DER_TAG_SET },
                { L("t61string"),       FR_DER_TAG_T61_STRING },
                { L("universalstring"), FR_DER_TAG_UNIVERSAL_STRING },
                { L("utctime"),         FR_DER_TAG_UTC_TIME },
                { L("utf8string"),      FR_DER_TAG_UTF8_STRING },
                { L("visiblestring"),   FR_DER_TAG_VISIBLE_STRING },
                { L("x509_extensions"), FR_DER_TAG_SEQUENCE }
        };
        static size_t der_tag_table_len = NUM_ELEMENTS(der_tag_table);
 
        fr_der_attr_flags_t     *flags = fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        fr_der_tag_t    der_type;
        fr_type_t               fr_type;
 
        /*
         *      To avoid confusion, we want to use the DER names where
         *      possible.
         *
         *      We only use the FreeRADIUS names where we don't have a
         *      choice. :(
         */
        switch (*type_p) {
        case FR_TYPE_TLV:
                fr_strerror_const("Cannot use 'tlv' in DER.  Please use 'sequence'");
                return false;
 
        default:
        invalid_type:
                fr_strerror_printf("Cannot use type '%s' in the DER dictionaries",
                                   fr_type_to_str(*type_p));
                return false;
 
                /*
                 *      We allow all integer types.  They may be
                 *      internal, or they may be inside of a struct.
                 */
        case FR_TYPE_NULL:
        case FR_TYPE_INTEGER:
        case FR_TYPE_VARIABLE_SIZE:
        case FR_TYPE_IPV4_ADDR:
        case FR_TYPE_IPV4_PREFIX:
        case FR_TYPE_IPV6_ADDR:
        case FR_TYPE_IPV6_PREFIX:
        case FR_TYPE_COMBO_IP_ADDR:
        case FR_TYPE_STRUCT:
        case FR_TYPE_GROUP:
        case FR_TYPE_ATTR:
                break;
        }
 
        /*
         *      Convert the DER data type to the underlying FreeRADIUS
         *      data type.
         *
         *      If we don't know anything about the data type then
         *      it's either bad, or a data type which we don't care
         *      about.  We set the der_type, and then return to the
         *      caller.  It will check *type_p, which is likely
         *      FR_TYPE_NULL, and will print an error.
         *
         *      "return true" here means "I dunno, you deal with it".
         */
        fr_type = fr_table_value_by_str(type_table, name, FR_TYPE_MAX);
        if (fr_type == FR_TYPE_MAX) {
                flags->der_type = fr_type_to_der_tag_default(*type_p);
                if (!flags->der_type) goto invalid_type;
                return true;
        }
 
        /*
         *      Now that we've converted the DER type to the
         *      underlying FreeRADIUS type, we get the corresponding
         *      DER type.  This MUST exist, as the two tables MUST
         *      have the same names.
         *
         *      @todo - arguably they should be in one table....
         */
        der_type = fr_table_value_by_str(der_tag_table, name, FR_DER_TAG_INVALID);
        fr_assert(der_type != FR_DER_TAG_INVALID);
 
        /*
         *      The der type is set only if there are extra flags seen
         *      and parsed by attr_valid().
         */
        fr_assert(flags->der_type == FR_DER_TAG_INVALID);
 
        /*
         *      Only now do we update the output data type.  From here
         *      on in, any validation failure will return 'false', and
         *      not 'true'.
         */
        *type_p = fr_type;
        flags->der_type = der_type;
 
        if (der_type == FR_DER_TAG_OID) {
                fr_dict_attr_ext_ref_t *ext;
 
                fr_assert(fr_type == FR_TYPE_ATTR);
 
                fr_assert(!fr_dict_attr_ext(*da_p, FR_DICT_ATTR_EXT_REF));
 
                ext = dict_attr_ext_alloc(da_p, FR_DICT_ATTR_EXT_REF); /* can change da_p */
                if (unlikely(!ext)) return -1;
 
                if (!attr_oid_tree) {
                        attr_oid_tree = fr_dict_attr_by_name(NULL, fr_dict_root((*da_p)->dict), "OID-Tree");
                        fr_assert(attr_oid_tree != NULL);
                }
 
                ext->type = FR_DICT_ATTR_REF_ROOT;
                ext->ref = attr_oid_tree;
        }
 
        /*
         *      If it is a collection of x509 extensions, we will set
         *      a few other flags as per RFC 5280.
         */
        if (strcmp(name, "x509_extensions") == 0) {
                flags->is_extensions = true;
 
                flags->class = FR_DER_CLASS_CONTEXT;
                flags->option = 3;
                flags->is_option = true;
 
                if (dict_flag_set_oid_and_value(da_p, flags) < 0) return false;
        }
 
        /*
         *      If this is a choice, then the children MUST have a limited option.
         */
        flags->is_choice = (strcmp(name, "choice") == 0);
 
        return true;
}
 
static const fr_der_tag_t fr_type_to_der_tag_defaults[FR_TYPE_MAX + 1] = {
        [FR_TYPE_OCTETS]        = FR_DER_TAG_OCTETSTRING,
        [FR_TYPE_STRING]        = FR_DER_TAG_UTF8_STRING,
 
        [FR_TYPE_IPV4_ADDR]     = FR_DER_TAG_BITSTRING,
        [FR_TYPE_IPV4_PREFIX]   = FR_DER_TAG_BITSTRING,
        [FR_TYPE_IPV6_ADDR]     = FR_DER_TAG_BITSTRING,
        [FR_TYPE_IPV6_PREFIX]   = FR_DER_TAG_BITSTRING,
 
        [FR_TYPE_COMBO_IP_ADDR] = FR_DER_TAG_OCTETSTRING,
 
        [FR_TYPE_BOOL]          = FR_DER_TAG_BOOLEAN,
 
        [FR_TYPE_UINT8]         = FR_DER_TAG_INTEGER,
        [FR_TYPE_UINT16]        = FR_DER_TAG_INTEGER,
        [FR_TYPE_UINT32]        = FR_DER_TAG_INTEGER,
        [FR_TYPE_UINT64]        = FR_DER_TAG_INTEGER,
        [FR_TYPE_INT8]          = FR_DER_TAG_INTEGER,
        [FR_TYPE_INT16]         = FR_DER_TAG_INTEGER,
        [FR_TYPE_INT32]         = FR_DER_TAG_INTEGER,
        [FR_TYPE_INT64]         = FR_DER_TAG_INTEGER,
        [FR_TYPE_DATE]          = FR_DER_TAG_GENERALIZED_TIME,
        [FR_TYPE_TLV]           = FR_DER_TAG_SEQUENCE,
        [FR_TYPE_STRUCT]        = FR_DER_TAG_BITSTRING,
        [FR_TYPE_GROUP]         = FR_DER_TAG_SEQUENCE,
};
 
fr_der_tag_t fr_type_to_der_tag_default(fr_type_t type)
{
        return fr_type_to_der_tag_defaults[type];
}
 
static bool attr_valid(fr_dict_attr_t *da)
{
        fr_der_attr_flags_t *flags = fr_dict_attr_ext(da, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
        fr_der_attr_flags_t *parent;
 
        if (flags->is_choice && unlikely(!fr_type_is_tlv(da->type))) {
                fr_strerror_printf("Attribute %s of type %s is not allowed represent a collection of choices.",
                                   da->name, fr_type_to_str(da->type));
                return false;
        }
 
        /*
         *      The DER encoder / decoder assume that all pairs are FR_TYPE_INT64.
         *
         *      The "on the wire" DER data has variable-sized encoding for integers,
         *      and drops leading zeros.
         *
         *      For consistency, we disallow data types which the
         *      encoder/decoder don't handle.  Except for data types
         *      in structs, because the struct encoder/decoder takes
         *      care of those.
         */
        if (fr_type_is_integer_except_bool(da->type) &&
            !da->flags.internal &&
            (da->type != FR_TYPE_INT64) &&
            (da->type != FR_TYPE_DATE) && (da->type != FR_TYPE_TIME_DELTA) &&
            (da->parent->type != FR_TYPE_STRUCT)) {
                fr_strerror_printf("All integers in DER must be 'int64', and not '%s'",
                                   fr_type_to_str(da->type));
                return false;
        }
 
        if (flags->is_extensions) {
                if (da->type != FR_TYPE_GROUP) {
                        fr_strerror_printf("Extensions must be type 'group', and not '%s'",
                                           fr_type_to_str(da->type));
                        return false;
                }
 
#if 0
                /*
                 *      Group refs are added as unresolved refs, see dict_flag_ref(), and are resolved later
                 *      in dict_fixup_group_apply().
                 *
                 *      @todo - have a function called from dict_attr_finalize() ?
                 */
                if (!fr_dict_attr_ref(da)) {
                        fr_strerror_const("Attribute is 'x509_extensions', but is missing 'ref=OID-Tree'");
                        return false;
                }
#endif
 
                /*
                 *      Avoid run-time checks.
                 */
                if (!flags->max) flags->max = UINT64_MAX;
        }
 
        /*
         *      Either complain on invalid 'max', or set it to the maximum.
         */
        if ((flags->der_type != FR_DER_TAG_SET) && (flags->der_type != FR_DER_TAG_SEQUENCE)) {
                if (!flags->max) {
                        flags->max = DER_MAX_STR;
 
                } else if (flags->max > DER_MAX_STR) {
                        fr_strerror_printf("Invalid value of 'max' for DER type '%s'",
                                           fr_der_tag_to_str(flags->der_type));
                        return false;
                }
        }
 
        /*
         *      Set the restriction types, which make the run-time decoding a lot easier.
         */
        if (flags->is_set_of) {
                flags->restrictions = (1 << flags->set_of);
        }
 
        if (flags->is_sequence_of) {
                /*
                 *      If the sequence isn't a choice, it has to be a sequence of one thing.
                 *
                 *      If the sequence is group, then it has to be a sequence of sequences.
                 *
                 *      If the sequence is a TLV, then the children will update the restrictions.
                 */
                if (flags->sequence_of != FR_DER_TAG_CHOICE) {
                        flags->restrictions = (1 << flags->sequence_of);
 
                } else if (da->type == FR_TYPE_GROUP) {
#ifndef NDEBUG
                        fr_dict_attr_t const *ref;
 
                        ref = fr_dict_attr_ref(da);
                        if (ref) {
                                fr_assert(fr_der_flag_der_type(ref) == FR_DER_TAG_SEQUENCE);
                        }
#endif
 
                        /*
                         *      A group of choices is really a sequence of sequences.  i.e. x509extensions
                         *      contain only a sequence, as does sequence_of=oid_and_value.
                         */
                        flags->restrictions = (1 << FR_DER_TAG_SEQUENCE);
 
                } else {
                        /*
                         *      The children will update our restriction types.
                         */
                        fr_assert(da->type == FR_TYPE_TLV);
                }
        }
 
        /*
         *      If the parent is a choice, then the child MUST have a limited set of options / tags.
         */
        parent = fr_dict_attr_ext(da->parent, FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC);
 
        /*
         *      The attribute was defined with the full OID, and no 'option' flag.  Add it manually.
         */
        if ((parent->is_choice && !flags->is_option) ||
            (flags->class == FR_DER_CLASS_PRIVATE) || (flags->class == FR_DER_CLASS_APPLICATION)) {
                fr_assert(da->attr < FR_DER_TAG_VALUE_MAX);
 
                if (!flags->class) flags->class = FR_DER_CLASS_CONTEXT;
                flags->option = da->attr;
                flags->is_option = true;
        }
 
        /*
         *      Can't have duplicates.
         */
        if (flags->is_option) {
                if ((parent->restrictions & (1 << flags->option)) != 0) {
                        fr_strerror_printf("Parent %s already has a child with option %u - duplicates are not allowed",
                                           da->parent->name, flags->option);
                        return false;
                }
 
                parent->restrictions |= (1 << flags->option);
 
        } else if (parent->is_sequence_of && (parent->sequence_of == FR_DER_TAG_CHOICE)) {
                fr_assert(flags->der_type < FR_DER_TAG_VALUE_MAX);
 
                flags->class = FR_DER_CLASS_CONTEXT;
//              flags->option = flags->der_type;
 
                if ((parent->restrictions & (1 << flags->der_type)) != 0) {
                        fr_strerror_printf("Parent %s already has a child with tag %s - duplicates are not allowed",
                                           da->parent->name, fr_der_tag_to_str(flags->der_type));
                        return false;
                }
 
                parent->restrictions |= (1 << flags->der_type);
 
        } else if (parent->is_sequence_of) {
                if (flags->der_type != parent->sequence_of) {
                        fr_strerror_printf("Parent %s is a sequence_of=%s - a child cannot be %s",
                                           da->parent->name, fr_der_tag_to_str(parent->set_of),
                                           fr_der_tag_to_str(flags->der_type));
                        return false;
                }
 
                /*
                 *      A sequence can sometimes have mixed tags && options.
                 */
                fr_assert(!flags->is_option);
 
        } else if (parent->is_set_of) {
                if (flags->der_type != parent->set_of) {
                        fr_strerror_printf("Parent %s is a set_of=%s - a child cannot be %s",
                                           da->parent->name, fr_der_tag_to_str(parent->set_of),
                                           fr_der_tag_to_str(flags->der_type));
                        return false;
                }
        }
 
        if ((da->type == FR_TYPE_GROUP) && !da->flags.allow_flat) {
                if ((da->parent == attr_oid_tree) || da->parent->flags.allow_flat) {
                        da->flags.allow_flat = true;
                } else {                        
                        fr_dict_attr_t const *oid;
 
                        for (oid = da->parent; !oid->flags.is_root; oid = oid->parent) {
                                if (oid == attr_oid_tree) {
                                        da->flags.allow_flat = true;
                                        break;
                                }
                        }
                }
        }
 
        return true;
}
 
extern fr_dict_protocol_t libfreeradius_der_dict_protocol;
fr_dict_protocol_t        libfreeradius_der_dict_protocol = {
               .name                = "der",
               .default_type_size   = 4,
               .default_type_length = 4,
               .attr = {
                       .flags = {
                               .table    = der_flags,
                               .table_len = NUM_ELEMENTS(der_flags),
                               .len        = sizeof(fr_der_attr_flags_t),
                       },
                       .type_parse = type_parse,
                       .valid = attr_valid
               },
 
               .init    = fr_der_global_init,
               .free    = fr_der_global_free,
 
               // .decode = fr_der_decode_foreign,
               // .encode = fr_der_encode_foreign,
};