/*
* validator/val_sigcrypt.h - validator signature crypto functions.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains helper functions for the validator module.
* The functions help with signature verification and checking, the
* bridging between RR wireformat data and crypto calls.
*/
#ifndef VALIDATOR_VAL_SIGCRYPT_H
#define VALIDATOR_VAL_SIGCRYPT_H
#include "util/data/packed_rrset.h"
struct val_env;
struct module_env;
struct ub_packed_rrset_key;
struct rbtree_t;
struct regional;
struct sldns_buffer;
/** number of entries in algorithm needs array */
#define ALGO_NEEDS_MAX 256
/**
* Storage for algorithm needs. DNSKEY algorithms.
*/
struct algo_needs {
/** the algorithms (8-bit) with each a number.
* 0: not marked.
* 1: marked 'necessary but not yet fulfilled'
* 2: marked bogus.
* Indexed by algorithm number.
*/
uint8_t needs[ALGO_NEEDS_MAX];
/** the number of entries in the array that are unfulfilled */
size_t num;
};
/**
* Initialize algo needs structure, set algos from rrset as needed.
* Results are added to an existing need structure.
* @param n: struct with storage.
* @param dnskey: algos from this struct set as necessary. DNSKEY set.
* @param sigalg: adds to signalled algorithm list too.
*/
void algo_needs_init_dnskey_add(struct algo_needs* n,
struct ub_packed_rrset_key* dnskey, uint8_t* sigalg);
/**
* Initialize algo needs structure from a signalled algo list.
* @param n: struct with storage.
* @param sigalg: signalled algorithm list, numbers ends with 0.
*/
void algo_needs_init_list(struct algo_needs* n, uint8_t* sigalg);
/**
* Initialize algo needs structure, set algos from rrset as needed.
* @param n: struct with storage.
* @param ds: algos from this struct set as necessary. DS set.
* @param fav_ds_algo: filter to use only this DS algo.
* @param sigalg: list of signalled algos, constructed as output,
* provide size ALGO_NEEDS_MAX+1. list of algonumbers, ends with a zero.
*/
void algo_needs_init_ds(struct algo_needs* n, struct ub_packed_rrset_key* ds,
int fav_ds_algo, uint8_t* sigalg);
/**
* Mark this algorithm as a success, sec_secure, and see if we are done.
* @param n: storage structure processed.
* @param algo: the algorithm processed to be secure.
* @return if true, processing has finished successfully, we are satisfied.
*/
int algo_needs_set_secure(struct algo_needs* n, uint8_t algo);
/**
* Mark this algorithm a failure, sec_bogus. It can later be overridden
* by a success for this algorithm (with a different signature).
* @param n: storage structure processed.
* @param algo: the algorithm processed to be bogus.
*/
void algo_needs_set_bogus(struct algo_needs* n, uint8_t algo);
/**
* See how many algorithms are missing (not bogus or secure, but not processed)
* @param n: storage structure processed.
* @return number of algorithms missing after processing.
*/
size_t algo_needs_num_missing(struct algo_needs* n);
/**
* See which algo is missing.
* @param n: struct after processing.
* @return if 0 an algorithm was bogus, if a number, this algorithm was
* missing. So on 0, report why that was bogus, on number report a missing
* algorithm. There could be multiple missing, this reports the first one.
*/
int algo_needs_missing(struct algo_needs* n);
/**
* Format error reason for algorithm missing.
* @param env: module env with scratch for temp storage of string.
* @param alg: DNSKEY-algorithm missing.
* @param reason: destination.
* @param s: string, appended with 'with algorithm ..'.
*/
void algo_needs_reason(struct module_env* env, int alg, char** reason, char* s);
/**
* Check if dnskey matches a DS digest
* Does not check dnskey-keyid footprint, just the digest.
* @param env: module environment. Uses scratch space.
* @param dnskey_rrset: DNSKEY rrset.
* @param dnskey_idx: index of RR in rrset.
* @param ds_rrset: DS rrset
* @param ds_idx: index of RR in DS rrset.
* @return true if it matches, false on error, not supported or no match.
*/
int ds_digest_match_dnskey(struct module_env* env,
struct ub_packed_rrset_key* dnskey_rrset, size_t dnskey_idx,
struct ub_packed_rrset_key* ds_rrset, size_t ds_idx);
/**
* Get dnskey keytag, footprint value
* @param dnskey_rrset: DNSKEY rrset.
* @param dnskey_idx: index of RR in rrset.
* @return the keytag or 0 for badly formatted DNSKEYs.
*/
uint16_t dnskey_calc_keytag(struct ub_packed_rrset_key* dnskey_rrset,
size_t dnskey_idx);
/**
* Get DS keytag, footprint value that matches the DNSKEY keytag it signs.
* @param ds_rrset: DS rrset
* @param ds_idx: index of RR in DS rrset.
* @return the keytag or 0 for badly formatted DSs.
*/
uint16_t ds_get_keytag(struct ub_packed_rrset_key* ds_rrset, size_t ds_idx);
/**
* See if DNSKEY algorithm is supported
* @param dnskey_rrset: DNSKEY rrset.
* @param dnskey_idx: index of RR in rrset.
* @return true if supported.
*/
int dnskey_algo_is_supported(struct ub_packed_rrset_key* dnskey_rrset,
size_t dnskey_idx);
/**
* See if DS digest algorithm is supported
* @param ds_rrset: DS rrset
* @param ds_idx: index of RR in DS rrset.
* @return true if supported.
*/
int ds_digest_algo_is_supported(struct ub_packed_rrset_key* ds_rrset,
size_t ds_idx);
/**
* Get DS RR digest algorithm
* @param ds_rrset: DS rrset.
* @param ds_idx: which DS.
* @return algorithm or 0 if DS too short.
*/
int ds_get_digest_algo(struct ub_packed_rrset_key* ds_rrset, size_t ds_idx);
/**
* See if DS key algorithm is supported
* @param ds_rrset: DS rrset
* @param ds_idx: index of RR in DS rrset.
* @return true if supported.
*/
int ds_key_algo_is_supported(struct ub_packed_rrset_key* ds_rrset,
size_t ds_idx);
/**
* Get DS RR key algorithm. This value should match with the DNSKEY algo.
* @param k: DS rrset.
* @param idx: which DS.
* @return algorithm or 0 if DS too short.
*/
int ds_get_key_algo(struct ub_packed_rrset_key* k, size_t idx);
/**
* Get DNSKEY RR signature algorithm
* @param k: DNSKEY rrset.
* @param idx: which DNSKEY RR.
* @return algorithm or 0 if DNSKEY too short.
*/
int dnskey_get_algo(struct ub_packed_rrset_key* k, size_t idx);
/**
* Get DNSKEY RR flags
* @param k: DNSKEY rrset.
* @param idx: which DNSKEY RR.
* @return flags or 0 if DNSKEY too short.
*/
uint16_t dnskey_get_flags(struct ub_packed_rrset_key* k, size_t idx);
/**
* Verify rrset against dnskey rrset.
* @param env: module environment, scratch space is used.
* @param ve: validator environment, date settings.
* @param rrset: to be validated.
* @param dnskey: DNSKEY rrset, keyset to try.
* @param sigalg: if nonNULL provide downgrade protection otherwise one
* algorithm is enough.
* @param reason: if bogus, a string returned, fixed or alloced in scratch.
* @return SECURE if one key in the set verifies one rrsig.
* UNCHECKED on allocation errors, unsupported algorithms, malformed data,
* and BOGUS on verification failures (no keys match any signatures).
*/
enum sec_status dnskeyset_verify_rrset(struct module_env* env,
struct val_env* ve, struct ub_packed_rrset_key* rrset,
struct ub_packed_rrset_key* dnskey, uint8_t* sigalg, char** reason);
/**
* verify rrset against one specific dnskey (from rrset)
* @param env: module environment, scratch space is used.
* @param ve: validator environment, date settings.
* @param rrset: to be validated.
* @param dnskey: DNSKEY rrset, keyset.
* @param dnskey_idx: which key from the rrset to try.
* @param reason: if bogus, a string returned, fixed or alloced in scratch.
* @return secure if *this* key signs any of the signatures on rrset.
* unchecked on error or and bogus on bad signature.
*/
enum sec_status dnskey_verify_rrset(struct module_env* env,
struct val_env* ve, struct ub_packed_rrset_key* rrset,
struct ub_packed_rrset_key* dnskey, size_t dnskey_idx, char** reason);
/**
* verify rrset, with dnskey rrset, for a specific rrsig in rrset
* @param env: module environment, scratch space is used.
* @param ve: validator environment, date settings.
* @param now: current time for validation (can be overridden).
* @param rrset: to be validated.
* @param dnskey: DNSKEY rrset, keyset to try.
* @param sig_idx: which signature to try to validate.
* @param sortree: reused sorted order. Stored in region. Pass NULL at start,
* and for a new rrset.
* @param reason: if bogus, a string returned, fixed or alloced in scratch.
* @return secure if any key signs *this* signature. bogus if no key signs it,
* or unchecked on error.
*/
enum sec_status dnskeyset_verify_rrset_sig(struct module_env* env,
struct val_env* ve, time_t now, struct ub_packed_rrset_key* rrset,
struct ub_packed_rrset_key* dnskey, size_t sig_idx,
struct rbtree_t** sortree, char** reason);
/**
* verify rrset, with specific dnskey(from set), for a specific rrsig
* @param region: scratch region used for temporary allocation.
* @param buf: scratch buffer used for canonicalized rrset data.
* @param ve: validator environment, date settings.
* @param now: current time for validation (can be overridden).
* @param rrset: to be validated.
* @param dnskey: DNSKEY rrset, keyset.
* @param dnskey_idx: which key from the rrset to try.
* @param sig_idx: which signature to try to validate.
* @param sortree: pass NULL at start, the sorted rrset order is returned.
* pass it again for the same rrset.
* @param buf_canon: if true, the buffer is already canonical.
* pass false at start. pass old value only for same rrset and same
* signature (but perhaps different key) for reuse.
* @param reason: if bogus, a string returned, fixed or alloced in scratch.
* @return secure if this key signs this signature. unchecked on error or
* bogus if it did not validate.
*/
enum sec_status dnskey_verify_rrset_sig(struct regional* region,
struct sldns_buffer* buf, struct val_env* ve, time_t now,
struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* dnskey,
size_t dnskey_idx, size_t sig_idx,
struct rbtree_t** sortree, int* buf_canon, char** reason);
/**
* canonical compare for two tree entries
*/
int canonical_tree_compare(const void* k1, const void* k2);
/**
* Compare two rrsets and see if they are the same, canonicalised.
* The rrsets are not altered.
* @param region: temporary region.
* @param k1: rrset1
* @param k2: rrset2
* @return true if equal.
*/
int rrset_canonical_equal(struct regional* region,
struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2);
#endif /* VALIDATOR_VAL_SIGCRYPT_H */
