mirror of
https://github.com/pi-hole/dnsmasq.git
synced 2025-12-19 18:28:25 +00:00
Merge branch 'unsigned'
This commit is contained in:
@@ -31,6 +31,15 @@ version 2.73
|
||||
request for certain domains, before the correct answer can
|
||||
arrive. Thanks to Glen Huang for the patch.
|
||||
|
||||
Revisit the part of DNSSEC validation which determines if an
|
||||
unsigned answer is legit, or is in some part of the DNS
|
||||
tree which should be signed. Dnsmasq now works from the
|
||||
DNS root downward looking for the limit of signed
|
||||
delegations, rather than working bottom up. This is
|
||||
both more correct, and less likely to trip over broken
|
||||
nameservers in the unsigned parts of the DNS tree
|
||||
which don't respond well to DNSSEC queries.
|
||||
|
||||
|
||||
version 2.72
|
||||
Add ra-advrouter mode, for RFC-3775 mobile IPv6 support.
|
||||
|
||||
@@ -569,8 +569,9 @@ struct hostsfile {
|
||||
#define STAT_SECURE_WILDCARD 7
|
||||
#define STAT_NO_SIG 8
|
||||
#define STAT_NO_DS 9
|
||||
#define STAT_NEED_DS_NEG 10
|
||||
#define STAT_CHASE_CNAME 11
|
||||
#define STAT_NO_NS 10
|
||||
#define STAT_NEED_DS_NEG 11
|
||||
#define STAT_CHASE_CNAME 12
|
||||
|
||||
#define FREC_NOREBIND 1
|
||||
#define FREC_CHECKING_DISABLED 2
|
||||
@@ -604,7 +605,9 @@ struct frec {
|
||||
#ifdef HAVE_DNSSEC
|
||||
int class, work_counter;
|
||||
struct blockdata *stash; /* Saved reply, whilst we validate */
|
||||
size_t stash_len;
|
||||
struct blockdata *orig_domain; /* domain of original query, whilst
|
||||
we're seeing is if in unsigned domain */
|
||||
size_t stash_len, name_start, name_len;
|
||||
struct frec *dependent; /* Query awaiting internally-generated DNSKEY or DS query */
|
||||
struct frec *blocking_query; /* Query which is blocking us. */
|
||||
#endif
|
||||
@@ -1126,7 +1129,7 @@ int in_zone(struct auth_zone *zone, char *name, char **cut);
|
||||
size_t dnssec_generate_query(struct dns_header *header, char *end, char *name, int class, int type, union mysockaddr *addr);
|
||||
int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t n, char *name, char *keyname, int class);
|
||||
int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class);
|
||||
int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int *class, int *neganswer);
|
||||
int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int *class, int *neganswer, int *nons);
|
||||
int dnssec_chase_cname(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname);
|
||||
int dnskey_keytag(int alg, int flags, unsigned char *rdata, int rdlen);
|
||||
size_t filter_rrsigs(struct dns_header *header, size_t plen);
|
||||
|
||||
81
src/dnssec.c
81
src/dnssec.c
@@ -875,7 +875,6 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
|
||||
/* The DNS packet is expected to contain the answer to a DNSKEY query.
|
||||
Put all DNSKEYs in the answer which are valid into the cache.
|
||||
return codes:
|
||||
STAT_INSECURE No DNSKEYs in reply.
|
||||
STAT_SECURE At least one valid DNSKEY found and in cache.
|
||||
STAT_BOGUS No DNSKEYs found, which can be validated with DS,
|
||||
or self-sign for DNSKEY RRset is not valid, bad packet.
|
||||
@@ -896,12 +895,9 @@ int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, ch
|
||||
GETSHORT(qtype, p);
|
||||
GETSHORT(qclass, p);
|
||||
|
||||
if (qtype != T_DNSKEY || qclass != class)
|
||||
if (qtype != T_DNSKEY || qclass != class || ntohs(header->ancount) == 0)
|
||||
return STAT_BOGUS;
|
||||
|
||||
if (ntohs(header->ancount) == 0)
|
||||
return STAT_INSECURE;
|
||||
|
||||
/* See if we have cached a DS record which validates this key */
|
||||
if (!(crecp = cache_find_by_name(NULL, name, now, F_DS)))
|
||||
{
|
||||
@@ -1103,17 +1099,17 @@ int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, ch
|
||||
/* The DNS packet is expected to contain the answer to a DS query
|
||||
Put all DSs in the answer which are valid into the cache.
|
||||
return codes:
|
||||
STAT_INSECURE no DS in reply or not signed.
|
||||
STAT_SECURE At least one valid DS found and in cache.
|
||||
STAT_NO_DS It's proved there's no DS here.
|
||||
STAT_BOGUS At least one DS found, which fails validation, bad packet.
|
||||
STAT_NO_NS It's proved there's no DS _or_ NS here.
|
||||
STAT_BOGUS no DS in reply or not signed, fails validation, bad packet.
|
||||
STAT_NEED_DNSKEY DNSKEY records to validate a DS not found, name in keyname
|
||||
*/
|
||||
|
||||
int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class)
|
||||
{
|
||||
unsigned char *p = (unsigned char *)(header+1);
|
||||
int qtype, qclass, val, i, neganswer;
|
||||
int qtype, qclass, val, i, neganswer, nons;
|
||||
|
||||
if (ntohs(header->qdcount) != 1 ||
|
||||
!(p = skip_name(p, header, plen, 4)))
|
||||
@@ -1125,32 +1121,39 @@ int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char
|
||||
if (qtype != T_DS || qclass != class)
|
||||
val = STAT_BOGUS;
|
||||
else
|
||||
val = dnssec_validate_reply(now, header, plen, name, keyname, NULL, &neganswer);
|
||||
val = dnssec_validate_reply(now, header, plen, name, keyname, NULL, &neganswer, &nons);
|
||||
/* Note dnssec_validate_reply() will have cached positive answers */
|
||||
|
||||
if (val == STAT_NO_SIG)
|
||||
val = STAT_INSECURE;
|
||||
if (val == STAT_NO_SIG || val == STAT_INSECURE)
|
||||
val = STAT_BOGUS;
|
||||
|
||||
p = (unsigned char *)(header+1);
|
||||
extract_name(header, plen, &p, name, 1, 4);
|
||||
p += 4; /* qtype, qclass */
|
||||
|
||||
if (!(p = skip_section(p, ntohs(header->ancount), header, plen)))
|
||||
return STAT_BOGUS;
|
||||
val = STAT_BOGUS;
|
||||
|
||||
if (val == STAT_BOGUS)
|
||||
log_query(F_UPSTREAM, name, NULL, "BOGUS DS");
|
||||
|
||||
if ((val == STAT_SECURE || val == STAT_INSECURE) && neganswer)
|
||||
{
|
||||
int rdlen, flags = F_FORWARD | F_DS | F_NEG;
|
||||
log_query(F_UPSTREAM, name, NULL, "BOGUS DS");
|
||||
return STAT_BOGUS;
|
||||
}
|
||||
|
||||
/* By here, the answer is proved secure, and a positive answer has been cached. */
|
||||
if (val == STAT_SECURE && neganswer)
|
||||
{
|
||||
int rdlen, flags = F_FORWARD | F_DS | F_NEG | F_DNSSECOK;
|
||||
unsigned long ttl, minttl = ULONG_MAX;
|
||||
struct all_addr a;
|
||||
|
||||
if (RCODE(header) == NXDOMAIN)
|
||||
flags |= F_NXDOMAIN;
|
||||
|
||||
if (val == STAT_SECURE)
|
||||
flags |= F_DNSSECOK;
|
||||
/* We only cache validated DS records, DNSSECOK flag hijacked
|
||||
to store presence/absence of NS. */
|
||||
if (nons)
|
||||
flags &= ~F_DNSSECOK;
|
||||
|
||||
for (i = ntohs(header->nscount); i != 0; i--)
|
||||
{
|
||||
@@ -1197,9 +1200,11 @@ int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char
|
||||
cache_insert(name, &a, now, ttl, flags);
|
||||
|
||||
cache_end_insert();
|
||||
|
||||
log_query(F_UPSTREAM, name, NULL, nons ? "no delegation" : "no DS");
|
||||
}
|
||||
|
||||
return (val == STAT_SECURE) ? STAT_NO_DS : STAT_INSECURE;
|
||||
return nons ? STAT_NO_NS : STAT_NO_DS;
|
||||
}
|
||||
|
||||
return val;
|
||||
@@ -1323,13 +1328,16 @@ static int find_nsec_records(struct dns_header *header, size_t plen, unsigned ch
|
||||
}
|
||||
|
||||
static int prove_non_existence_nsec(struct dns_header *header, size_t plen, unsigned char **nsecs, int nsec_count,
|
||||
char *workspace1, char *workspace2, char *name, int type)
|
||||
char *workspace1, char *workspace2, char *name, int type, int *nons)
|
||||
{
|
||||
int i, rc, rdlen;
|
||||
unsigned char *p, *psave;
|
||||
int offset = (type & 0xff) >> 3;
|
||||
int mask = 0x80 >> (type & 0x07);
|
||||
|
||||
if (nons)
|
||||
*nons = 0;
|
||||
|
||||
/* Find NSEC record that proves name doesn't exist */
|
||||
for (i = 0; i < nsec_count; i++)
|
||||
{
|
||||
@@ -1355,6 +1363,10 @@ static int prove_non_existence_nsec(struct dns_header *header, size_t plen, unsi
|
||||
rdlen -= p - psave;
|
||||
/* rdlen is now length of type map, and p points to it */
|
||||
|
||||
/* If we can prove that there's no NS record, return that information. */
|
||||
if (nons && rdlen >= 2 && p[0] == 0 && (p[2] & (0x80 >> T_NS)) == 0)
|
||||
*nons = 1;
|
||||
|
||||
while (rdlen >= 2)
|
||||
{
|
||||
if (!CHECK_LEN(header, p, plen, rdlen))
|
||||
@@ -1456,7 +1468,7 @@ static int base32_decode(char *in, unsigned char *out)
|
||||
}
|
||||
|
||||
static int check_nsec3_coverage(struct dns_header *header, size_t plen, int digest_len, unsigned char *digest, int type,
|
||||
char *workspace1, char *workspace2, unsigned char **nsecs, int nsec_count)
|
||||
char *workspace1, char *workspace2, unsigned char **nsecs, int nsec_count, int *nons)
|
||||
{
|
||||
int i, hash_len, salt_len, base32_len, rdlen;
|
||||
unsigned char *p, *psave;
|
||||
@@ -1497,6 +1509,10 @@ static int check_nsec3_coverage(struct dns_header *header, size_t plen, int dige
|
||||
if (!CHECK_LEN(header, p, plen, rdlen))
|
||||
return 0;
|
||||
|
||||
/* If we can prove that there's no NS record, return that information. */
|
||||
if (nons && rdlen >= 2 && p[0] == 0 && (p[2] & (0x80 >> T_NS)) == 0)
|
||||
*nons = 1;
|
||||
|
||||
while (rdlen >= 2)
|
||||
{
|
||||
if (p[0] == type >> 8)
|
||||
@@ -1533,13 +1549,16 @@ static int check_nsec3_coverage(struct dns_header *header, size_t plen, int dige
|
||||
}
|
||||
|
||||
static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, unsigned char **nsecs, int nsec_count,
|
||||
char *workspace1, char *workspace2, char *name, int type, char *wildname)
|
||||
char *workspace1, char *workspace2, char *name, int type, char *wildname, int *nons)
|
||||
{
|
||||
unsigned char *salt, *p, *digest;
|
||||
int digest_len, i, iterations, salt_len, base32_len, algo = 0;
|
||||
struct nettle_hash const *hash;
|
||||
char *closest_encloser, *next_closest, *wildcard;
|
||||
|
||||
if (nons)
|
||||
*nons = 0;
|
||||
|
||||
/* Look though the NSEC3 records to find the first one with
|
||||
an algorithm we support (currently only algo == 1).
|
||||
|
||||
@@ -1612,7 +1631,7 @@ static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, uns
|
||||
if ((digest_len = hash_name(name, &digest, hash, salt, salt_len, iterations)) == 0)
|
||||
return STAT_BOGUS;
|
||||
|
||||
if (check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count))
|
||||
if (check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, nons))
|
||||
return STAT_SECURE;
|
||||
|
||||
/* Can't find an NSEC3 which covers the name directly, we need the "closest encloser NSEC3"
|
||||
@@ -1657,7 +1676,7 @@ static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, uns
|
||||
if ((digest_len = hash_name(next_closest, &digest, hash, salt, salt_len, iterations)) == 0)
|
||||
return STAT_BOGUS;
|
||||
|
||||
if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count))
|
||||
if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, NULL))
|
||||
return STAT_BOGUS;
|
||||
|
||||
/* Finally, check that there's no seat of wildcard synthesis */
|
||||
@@ -1672,7 +1691,7 @@ static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, uns
|
||||
if ((digest_len = hash_name(wildcard, &digest, hash, salt, salt_len, iterations)) == 0)
|
||||
return STAT_BOGUS;
|
||||
|
||||
if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count))
|
||||
if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, NULL))
|
||||
return STAT_BOGUS;
|
||||
}
|
||||
|
||||
@@ -1681,7 +1700,8 @@ static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, uns
|
||||
|
||||
/* Validate all the RRsets in the answer and authority sections of the reply (4035:3.2.3) */
|
||||
/* Returns are the same as validate_rrset, plus the class if the missing key is in *class */
|
||||
int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int *class, int *neganswer)
|
||||
int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname,
|
||||
int *class, int *neganswer, int *nons)
|
||||
{
|
||||
unsigned char *ans_start, *qname, *p1, *p2, **nsecs;
|
||||
int type1, class1, rdlen1, type2, class2, rdlen2, qclass, qtype;
|
||||
@@ -1811,9 +1831,10 @@ int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, ch
|
||||
return STAT_BOGUS; /* No NSECs or bad packet */
|
||||
|
||||
if (nsec_type == T_NSEC)
|
||||
rc = prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, type1);
|
||||
rc = prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, type1, NULL);
|
||||
else
|
||||
rc = prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, type1, wildname);
|
||||
rc = prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename,
|
||||
keyname, name, type1, wildname, NULL);
|
||||
|
||||
if (rc != STAT_SECURE)
|
||||
return rc;
|
||||
@@ -1937,9 +1958,9 @@ int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, ch
|
||||
return STAT_BOGUS;
|
||||
|
||||
if (nsec_type == T_NSEC)
|
||||
return prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype);
|
||||
return prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype, nons);
|
||||
else
|
||||
return prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype, NULL);
|
||||
return prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype, NULL, nons);
|
||||
}
|
||||
|
||||
/* Chase the CNAME chain in the packet until the first record which _doesn't validate.
|
||||
|
||||
270
src/forward.c
270
src/forward.c
@@ -26,8 +26,9 @@ static void free_frec(struct frec *f);
|
||||
#ifdef HAVE_DNSSEC
|
||||
static int tcp_key_recurse(time_t now, int status, struct dns_header *header, size_t n,
|
||||
int class, char *name, char *keyname, struct server *server, int *keycount);
|
||||
static int do_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class);
|
||||
static int send_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname);
|
||||
static int do_check_sign(struct frec *forward, int status, time_t now, char *name, char *keyname);
|
||||
static int send_check_sign(struct frec *forward, time_t now, struct dns_header *header, size_t plen,
|
||||
char *name, char *keyname);
|
||||
#endif
|
||||
|
||||
|
||||
@@ -815,18 +816,22 @@ void reply_query(int fd, int family, time_t now)
|
||||
else if (forward->flags & FREC_DS_QUERY)
|
||||
{
|
||||
status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
|
||||
if (status == STAT_NO_DS)
|
||||
status = STAT_INSECURE;
|
||||
if (status == STAT_NO_DS || status == STAT_NO_NS)
|
||||
status = STAT_BOGUS;
|
||||
}
|
||||
else if (forward->flags & FREC_CHECK_NOSIGN)
|
||||
status = do_check_sign(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
|
||||
{
|
||||
status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
|
||||
if (status != STAT_NEED_KEY)
|
||||
status = do_check_sign(forward, status, now, daemon->namebuff, daemon->keyname);
|
||||
}
|
||||
else
|
||||
{
|
||||
status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL);
|
||||
status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL, NULL);
|
||||
if (status == STAT_NO_SIG)
|
||||
{
|
||||
if (option_bool(OPT_DNSSEC_NO_SIGN))
|
||||
status = send_check_sign(now, header, n, daemon->namebuff, daemon->keyname);
|
||||
status = send_check_sign(forward, now, header, n, daemon->namebuff, daemon->keyname);
|
||||
else
|
||||
status = STAT_INSECURE;
|
||||
}
|
||||
@@ -861,6 +866,7 @@ void reply_query(int fd, int family, time_t now)
|
||||
new->blocking_query = NULL;
|
||||
new->sentto = server;
|
||||
new->rfd4 = NULL;
|
||||
new->orig_domain = NULL;
|
||||
#ifdef HAVE_IPV6
|
||||
new->rfd6 = NULL;
|
||||
#endif
|
||||
@@ -889,7 +895,9 @@ void reply_query(int fd, int family, time_t now)
|
||||
new->new_id = get_id();
|
||||
header->id = htons(new->new_id);
|
||||
/* Save query for retransmission */
|
||||
new->stash = blockdata_alloc((char *)header, nn);
|
||||
if (!(new->stash = blockdata_alloc((char *)header, nn)))
|
||||
return;
|
||||
|
||||
new->stash_len = nn;
|
||||
|
||||
/* Don't resend this. */
|
||||
@@ -946,18 +954,22 @@ void reply_query(int fd, int family, time_t now)
|
||||
else if (forward->flags & FREC_DS_QUERY)
|
||||
{
|
||||
status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
|
||||
if (status == STAT_NO_DS)
|
||||
status = STAT_INSECURE;
|
||||
if (status == STAT_NO_DS || status == STAT_NO_NS)
|
||||
status = STAT_BOGUS;
|
||||
}
|
||||
else if (forward->flags & FREC_CHECK_NOSIGN)
|
||||
status = do_check_sign(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
|
||||
{
|
||||
status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
|
||||
if (status != STAT_NEED_KEY)
|
||||
status = do_check_sign(forward, status, now, daemon->namebuff, daemon->keyname);
|
||||
}
|
||||
else
|
||||
{
|
||||
status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL);
|
||||
status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL, NULL);
|
||||
if (status == STAT_NO_SIG)
|
||||
{
|
||||
if (option_bool(OPT_DNSSEC_NO_SIGN))
|
||||
status = send_check_sign(now, header, n, daemon->namebuff, daemon->keyname);
|
||||
status = send_check_sign(forward, now, header, n, daemon->namebuff, daemon->keyname);
|
||||
else
|
||||
status = STAT_INSECURE;
|
||||
}
|
||||
@@ -1319,70 +1331,80 @@ void receive_query(struct listener *listen, time_t now)
|
||||
/* UDP: we've got an unsigned answer, return STAT_INSECURE if we can prove there's no DS
|
||||
and therefore the answer shouldn't be signed, or STAT_BOGUS if it should be, or
|
||||
STAT_NEED_DS_NEG and keyname if we need to do the query. */
|
||||
static int send_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname)
|
||||
static int send_check_sign(struct frec *forward, time_t now, struct dns_header *header, size_t plen,
|
||||
char *name, char *keyname)
|
||||
{
|
||||
struct crec *crecp;
|
||||
char *name_start = name;
|
||||
int status = dnssec_chase_cname(now, header, plen, name, keyname);
|
||||
|
||||
if (status != STAT_INSECURE)
|
||||
return status;
|
||||
|
||||
while (1)
|
||||
{
|
||||
crecp = cache_find_by_name(NULL, name_start, now, F_DS);
|
||||
|
||||
if (crecp && (crecp->flags & F_DNSSECOK))
|
||||
return (crecp->flags & F_NEG) ? STAT_INSECURE : STAT_BOGUS;
|
||||
|
||||
if (crecp && (crecp->flags & F_NEG) && (name_start = strchr(name_start, '.')))
|
||||
{
|
||||
name_start++; /* chop a label off and try again */
|
||||
continue;
|
||||
}
|
||||
|
||||
/* Reached the root */
|
||||
if (!name_start)
|
||||
/* Store the domain we're trying to check. */
|
||||
forward->name_start = strlen(name);
|
||||
forward->name_len = forward->name_start + 1;
|
||||
if (!(forward->orig_domain = blockdata_alloc(name, forward->name_len)))
|
||||
return STAT_BOGUS;
|
||||
|
||||
strcpy(keyname, name_start);
|
||||
return STAT_NEED_DS_NEG;
|
||||
}
|
||||
return do_check_sign(forward, 0, now, name, keyname);
|
||||
}
|
||||
|
||||
/* Got answer to DS query from send_check_sign, check for proven non-existence, or make the next DS query to try. */
|
||||
static int do_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class)
|
||||
|
||||
/* We either have a a reply (header non-NULL, or we need to start by looking in the cache */
|
||||
static int do_check_sign(struct frec *forward, int status, time_t now, char *name, char *keyname)
|
||||
{
|
||||
char *name_start;
|
||||
unsigned char *p;
|
||||
int status;
|
||||
/* get domain we're checking back from blockdata store, it's stored on the original query. */
|
||||
while (forward->dependent)
|
||||
forward = forward->dependent;
|
||||
|
||||
/* In this case only, a SERVFAIL reply allows us to continue up the tree, looking for a
|
||||
suitable NSEC reply to DS queries. */
|
||||
if (RCODE(header) != SERVFAIL)
|
||||
blockdata_retrieve(forward->orig_domain, forward->name_len, name);
|
||||
|
||||
while (1)
|
||||
{
|
||||
status = dnssec_validate_ds(now, header, plen, name, keyname, class);
|
||||
char *p;
|
||||
|
||||
if (status != STAT_INSECURE)
|
||||
if (status == 0)
|
||||
{
|
||||
if (status == STAT_NO_DS)
|
||||
status = STAT_INSECURE;
|
||||
return status;
|
||||
}
|
||||
}
|
||||
struct crec *crecp;
|
||||
|
||||
p = (unsigned char *)(header+1);
|
||||
|
||||
if (extract_name(header, plen, &p, name, 1, 4) &&
|
||||
(name_start = strchr(name, '.')))
|
||||
/* Haven't received answer, see if in cache */
|
||||
if (!(crecp = cache_find_by_name(NULL, &name[forward->name_start], now, F_DS)))
|
||||
{
|
||||
name_start++; /* chop a label off and try again */
|
||||
strcpy(keyname, name_start);
|
||||
/* put name of DS record we're missing into keyname */
|
||||
strcpy(keyname, &name[forward->name_start]);
|
||||
/* and wait for reply to arrive */
|
||||
return STAT_NEED_DS_NEG;
|
||||
}
|
||||
|
||||
/* F_DNSSECOK misused in DS cache records to non-existance of NS record */
|
||||
if (!(crecp->flags & F_NEG))
|
||||
status = STAT_SECURE;
|
||||
else if (crecp->flags & F_DNSSECOK)
|
||||
status = STAT_NO_DS;
|
||||
else
|
||||
status = STAT_NO_NS;
|
||||
}
|
||||
|
||||
/* Have entered non-signed part of DNS tree. */
|
||||
if (status == STAT_NO_DS)
|
||||
return STAT_INSECURE;
|
||||
|
||||
if (status == STAT_BOGUS)
|
||||
return STAT_BOGUS;
|
||||
|
||||
/* There's a proven DS record, or we're within a zone, where there doesn't need
|
||||
to be a DS record. Add a name and try again.
|
||||
If we've already tried the whole name, then fail */
|
||||
|
||||
if (forward->name_start == 0)
|
||||
return STAT_BOGUS;
|
||||
|
||||
for (p = &name[forward->name_start-2]; (*p != '.') && (p != name); p--);
|
||||
|
||||
if (p != name)
|
||||
p++;
|
||||
|
||||
forward->name_start = p - name;
|
||||
status = 0; /* force to cache when we iterate. */
|
||||
}
|
||||
}
|
||||
|
||||
/* Move toward the root, until we find a signed non-existance of a DS, in which case
|
||||
@@ -1394,9 +1416,10 @@ static int tcp_check_for_unsigned_zone(time_t now, struct dns_header *header, s
|
||||
size_t m;
|
||||
unsigned char *packet, *payload;
|
||||
u16 *length;
|
||||
unsigned char *p = (unsigned char *)(header+1);
|
||||
int status;
|
||||
char *name_start = name;
|
||||
int status, name_len;
|
||||
struct blockdata *block;
|
||||
|
||||
char *name_start;
|
||||
|
||||
/* Get first insecure entry in CNAME chain */
|
||||
status = tcp_key_recurse(now, STAT_CHASE_CNAME, header, plen, class, name, keyname, server, keycount);
|
||||
@@ -1410,46 +1433,59 @@ static int tcp_check_for_unsigned_zone(time_t now, struct dns_header *header, s
|
||||
header = (struct dns_header *)payload;
|
||||
length = (u16 *)packet;
|
||||
|
||||
/* Stash the name away, since the buffer will be trashed when we recurse */
|
||||
name_len = strlen(name) + 1;
|
||||
name_start = name + name_len - 1;
|
||||
|
||||
if (!(block = blockdata_alloc(name, name_len)))
|
||||
{
|
||||
free(packet);
|
||||
return STAT_BOGUS;
|
||||
}
|
||||
|
||||
while (1)
|
||||
{
|
||||
unsigned char *newhash, hash[HASH_SIZE];
|
||||
unsigned char c1, c2;
|
||||
struct crec *crecp = cache_find_by_name(NULL, name_start, now, F_DS);
|
||||
struct crec *crecp;
|
||||
|
||||
if (--(*keycount) == 0)
|
||||
{
|
||||
free(packet);
|
||||
blockdata_free(block);
|
||||
return STAT_BOGUS;
|
||||
}
|
||||
|
||||
if (crecp && (crecp->flags & F_DNSSECOK))
|
||||
while ((crecp = cache_find_by_name(NULL, name_start, now, F_DS)))
|
||||
{
|
||||
if ((crecp->flags & F_NEG) && (crecp->flags & F_DNSSECOK))
|
||||
{
|
||||
/* Found a secure denial of DS - delegation is indeed insecure */
|
||||
free(packet);
|
||||
return (crecp->flags & F_NEG) ? STAT_INSECURE : STAT_BOGUS;
|
||||
blockdata_free(block);
|
||||
return STAT_INSECURE;
|
||||
}
|
||||
|
||||
/* If we have cached insecurely that a DS doesn't exist,
|
||||
ise that is a hit for where to start looking for the secure one */
|
||||
if (crecp && (crecp->flags & F_NEG) && (name_start = strchr(name_start, '.')))
|
||||
{
|
||||
name_start++; /* chop a label off and try again */
|
||||
continue;
|
||||
}
|
||||
/* Here, either there's a secure DS, or no NS and no DS, and therefore no delegation.
|
||||
Add another label and continue. */
|
||||
|
||||
/* reached the root */
|
||||
if (!name_start)
|
||||
if (name_start == name)
|
||||
{
|
||||
free(packet);
|
||||
return STAT_BOGUS;
|
||||
blockdata_free(block);
|
||||
return STAT_BOGUS; /* run out of labels */
|
||||
}
|
||||
|
||||
name_start -= 2;
|
||||
while (*name_start != '.' && name_start != name)
|
||||
name_start--;
|
||||
if (name_start != name)
|
||||
name_start++;
|
||||
}
|
||||
|
||||
/* Can't find it in the cache, have to send a query */
|
||||
|
||||
m = dnssec_generate_query(header, ((char *) header) + 65536, name_start, class, T_DS, &server->addr);
|
||||
|
||||
/* We rely on the question section coming back unchanged, ensure it is with the hash. */
|
||||
if ((newhash = hash_questions(header, (unsigned int)m, name)))
|
||||
{
|
||||
memcpy(hash, newhash, HASH_SIZE);
|
||||
|
||||
*length = htons(m);
|
||||
|
||||
if (read_write(server->tcpfd, packet, m + sizeof(u16), 0) &&
|
||||
@@ -1459,46 +1495,51 @@ static int tcp_check_for_unsigned_zone(time_t now, struct dns_header *header, s
|
||||
{
|
||||
m = (c1 << 8) | c2;
|
||||
|
||||
newhash = hash_questions(header, (unsigned int)m, name);
|
||||
if (newhash && memcmp(hash, newhash, HASH_SIZE) == 0)
|
||||
{
|
||||
/* In this case only, a SERVFAIL reply allows us to continue up the tree, looking for a
|
||||
suitable NSEC reply to DS queries. */
|
||||
if (RCODE(header) == SERVFAIL)
|
||||
status = STAT_INSECURE;
|
||||
else
|
||||
/* Note this trashes all three name workspaces */
|
||||
status = tcp_key_recurse(now, STAT_NEED_DS_NEG, header, m, class, name, keyname, server, keycount);
|
||||
|
||||
/* We've found a DS which proves the bit of the DNS where the
|
||||
original query is, is unsigned, so the answer is OK,
|
||||
if unvalidated. */
|
||||
if (status == STAT_NO_DS)
|
||||
{
|
||||
/* Found a secure denial of DS - delegation is indeed insecure */
|
||||
free(packet);
|
||||
blockdata_free(block);
|
||||
return STAT_INSECURE;
|
||||
}
|
||||
|
||||
/* No DS, not got to DNSSEC-land yet, go up. */
|
||||
if (status == STAT_INSECURE)
|
||||
if (status == STAT_BOGUS)
|
||||
{
|
||||
p = (unsigned char *)(header+1);
|
||||
|
||||
if (extract_name(header, plen, &p, name, 1, 4) &&
|
||||
(name_start = strchr(name, '.')))
|
||||
{
|
||||
name_start++; /* chop a label off and try again */
|
||||
continue;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
free(packet);
|
||||
|
||||
blockdata_free(block);
|
||||
return STAT_BOGUS;
|
||||
}
|
||||
|
||||
/* Here, either there's a secure DS, or no NS and no DS, and therefore no delegation.
|
||||
Add another label and continue. */
|
||||
|
||||
/* Get name we're checking back. */
|
||||
blockdata_retrieve(block, name_len, name);
|
||||
|
||||
if (name_start == name)
|
||||
{
|
||||
free(packet);
|
||||
blockdata_free(block);
|
||||
return STAT_BOGUS; /* run out of labels */
|
||||
}
|
||||
|
||||
name_start -= 2;
|
||||
while (*name_start != '.' && name_start != name)
|
||||
name_start--;
|
||||
if (name_start != name)
|
||||
name_start++;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* IO failure */
|
||||
free(packet);
|
||||
blockdata_free(block);
|
||||
return STAT_BOGUS; /* run out of labels */
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static int tcp_key_recurse(time_t now, int status, struct dns_header *header, size_t n,
|
||||
@@ -1516,14 +1557,14 @@ static int tcp_key_recurse(time_t now, int status, struct dns_header *header, si
|
||||
else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG)
|
||||
{
|
||||
new_status = dnssec_validate_ds(now, header, n, name, keyname, class);
|
||||
if (status == STAT_NEED_DS && new_status == STAT_NO_DS)
|
||||
new_status = STAT_INSECURE;
|
||||
if (status == STAT_NEED_DS && (new_status == STAT_NO_DS || new_status == STAT_NO_NS))
|
||||
new_status = STAT_BOGUS;
|
||||
}
|
||||
else if (status == STAT_CHASE_CNAME)
|
||||
new_status = dnssec_chase_cname(now, header, n, name, keyname);
|
||||
else
|
||||
{
|
||||
new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL);
|
||||
new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL, NULL);
|
||||
|
||||
if (new_status == STAT_NO_SIG)
|
||||
{
|
||||
@@ -1576,14 +1617,14 @@ static int tcp_key_recurse(time_t now, int status, struct dns_header *header, si
|
||||
else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG)
|
||||
{
|
||||
new_status = dnssec_validate_ds(now, header, n, name, keyname, class);
|
||||
if (status == STAT_NEED_DS && new_status == STAT_NO_DS)
|
||||
new_status = STAT_INSECURE; /* Validated no DS */
|
||||
if (status == STAT_NEED_DS && (new_status == STAT_NO_DS || new_status == STAT_NO_NS))
|
||||
new_status = STAT_BOGUS; /* Validated no DS */
|
||||
}
|
||||
else if (status == STAT_CHASE_CNAME)
|
||||
new_status = dnssec_chase_cname(now, header, n, name, keyname);
|
||||
else
|
||||
{
|
||||
new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL);
|
||||
new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL, NULL);
|
||||
|
||||
if (new_status == STAT_NO_SIG)
|
||||
{
|
||||
@@ -1961,6 +2002,7 @@ static struct frec *allocate_frec(time_t now)
|
||||
f->dependent = NULL;
|
||||
f->blocking_query = NULL;
|
||||
f->stash = NULL;
|
||||
f->orig_domain = NULL;
|
||||
#endif
|
||||
daemon->frec_list = f;
|
||||
}
|
||||
@@ -2029,6 +2071,12 @@ static void free_frec(struct frec *f)
|
||||
f->stash = NULL;
|
||||
}
|
||||
|
||||
if (f->orig_domain)
|
||||
{
|
||||
blockdata_free(f->orig_domain);
|
||||
f->orig_domain = NULL;
|
||||
}
|
||||
|
||||
/* Anything we're waiting on is pointless now, too */
|
||||
if (f->blocking_query)
|
||||
free_frec(f->blocking_query);
|
||||
|
||||
Reference in New Issue
Block a user