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#ifndef UNBOUND_DNSCRYPT_H
#define UNBOUND_DNSCRYPT_H
/**
* \file
* dnscrypt functions for encrypting DNS packets.
*/
#include "dnscrypt/dnscrypt_config.h"
#ifdef USE_DNSCRYPT
#define DNSCRYPT_MAGIC_HEADER_LEN 8U
#define DNSCRYPT_MAGIC_RESPONSE "r6fnvWj8"
#ifndef DNSCRYPT_MAX_PADDING
# define DNSCRYPT_MAX_PADDING 256U
#endif
#ifndef DNSCRYPT_BLOCK_SIZE
# define DNSCRYPT_BLOCK_SIZE 64U
#endif
#ifndef DNSCRYPT_MIN_PAD_LEN
# define DNSCRYPT_MIN_PAD_LEN 8U
#endif
#define crypto_box_HALF_NONCEBYTES (crypto_box_NONCEBYTES / 2U)
#include "config.h"
#include "dnscrypt/cert.h"
#include "util/locks.h"
#define DNSCRYPT_QUERY_HEADER_SIZE \
(DNSCRYPT_MAGIC_HEADER_LEN + crypto_box_PUBLICKEYBYTES + crypto_box_HALF_NONCEBYTES + crypto_box_MACBYTES)
#define DNSCRYPT_RESPONSE_HEADER_SIZE \
(DNSCRYPT_MAGIC_HEADER_LEN + crypto_box_NONCEBYTES + crypto_box_MACBYTES)
#define DNSCRYPT_REPLY_HEADER_SIZE \
(DNSCRYPT_MAGIC_HEADER_LEN + crypto_box_HALF_NONCEBYTES * 2 + crypto_box_MACBYTES)
struct sldns_buffer;
struct config_file;
struct comm_reply;
struct slabhash;
typedef struct KeyPair_ {
uint8_t crypt_publickey[crypto_box_PUBLICKEYBYTES];
uint8_t crypt_secretkey[crypto_box_SECRETKEYBYTES];
} KeyPair;
typedef struct cert_ {
uint8_t magic_query[DNSCRYPT_MAGIC_HEADER_LEN];
uint8_t es_version[2];
KeyPair *keypair;
} dnsccert;
struct dnsc_env {
struct SignedCert *signed_certs;
struct SignedCert **rotated_certs;
dnsccert *certs;
size_t signed_certs_count;
size_t rotated_certs_count;
uint8_t provider_publickey[crypto_sign_ed25519_PUBLICKEYBYTES];
uint8_t provider_secretkey[crypto_sign_ed25519_SECRETKEYBYTES];
KeyPair *keypairs;
size_t keypairs_count;
uint64_t nonce_ts_last;
unsigned char hash_key[crypto_shorthash_KEYBYTES];
char * provider_name;
/** Caches */
struct slabhash *shared_secrets_cache;
/** lock on shared secret cache counters */
lock_basic_type shared_secrets_cache_lock;
/** number of misses from shared_secrets_cache */
size_t num_query_dnscrypt_secret_missed_cache;
/** slabhash keeping track of nonce/cient pk/server sk pairs. */
struct slabhash *nonces_cache;
/** lock on nonces_cache, used to avoid race condition in updating the hash */
lock_basic_type nonces_cache_lock;
/** number of replayed queries */
size_t num_query_dnscrypt_replay;
};
struct dnscrypt_query_header {
uint8_t magic_query[DNSCRYPT_MAGIC_HEADER_LEN];
uint8_t publickey[crypto_box_PUBLICKEYBYTES];
uint8_t nonce[crypto_box_HALF_NONCEBYTES];
uint8_t mac[crypto_box_MACBYTES];
};
/**
* Initialize DNSCrypt environment.
* Initialize sodium library and allocate the dnsc_env structure.
* \return an uninitialized struct dnsc_env.
*/
struct dnsc_env * dnsc_create(void);
/**
* Apply configuration.
* Read certificates and secret keys from configuration. Initialize hashkey and
* provider name as well as loading cert TXT records.
* In case of issue applying configuration, this function fatals.
* \param[in] env the struct dnsc_env to populate.
* \param[in] cfg the config_file struct with dnscrypt options.
* \return 0 on success.
*/
int dnsc_apply_cfg(struct dnsc_env *env, struct config_file *cfg);
/**
* Delete DNSCrypt environment
*
*/
void dnsc_delete(struct dnsc_env *env);
/**
* handle a crypted dnscrypt request.
* Determine wether or not a query is coming over the dnscrypt listener and
* attempt to uncurve it or detect if it is a certificate query.
* return 0 in case of failure.
*/
int dnsc_handle_curved_request(struct dnsc_env* dnscenv,
struct comm_reply* repinfo);
/**
* handle an unencrypted dnscrypt request.
* Determine wether or not a query is going over the dnscrypt channel and
* attempt to curve it unless it was not crypted like when it is a
* certificate query.
* \return 0 in case of failure.
*/
int dnsc_handle_uncurved_request(struct comm_reply *repinfo);
/**
* Computes the size of the shared secret cache entry.
*/
size_t dnsc_shared_secrets_sizefunc(void *k, void *d);
/**
* Compares two shared secret cache keys.
*/
int dnsc_shared_secrets_compfunc(void *m1, void *m2);
/**
* Function to delete a shared secret cache key.
*/
void dnsc_shared_secrets_delkeyfunc(void *k, void* arg);
/**
* Function to delete a share secret cache value.
*/
void dnsc_shared_secrets_deldatafunc(void* d, void* arg);
/**
* Computes the size of the nonce cache entry.
*/
size_t dnsc_nonces_sizefunc(void *k, void *d);
/**
* Compares two nonce cache keys.
*/
int dnsc_nonces_compfunc(void *m1, void *m2);
/**
* Function to delete a nonce cache key.
*/
void dnsc_nonces_delkeyfunc(void *k, void* arg);
/**
* Function to delete a nonce cache value.
*/
void dnsc_nonces_deldatafunc(void* d, void* arg);
#endif /* USE_DNSCRYPT */
#endif
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