static isc_result_t
process_deletetkey(dns_message_t *msg, dns_name_t *signer, dns_name_t *name,
dns_rdata_tkey_t *tkeyin,
dns_rdata_tkey_t *tkeyout,
dns_tsig_keyring_t *ring,
dns_namelist_t *namelist)
{
isc_result_t result;
dns_tsigkey_t *tsigkey = NULL;
dns_name_t *identity;
UNUSED(msg);
UNUSED(namelist);
result = dns_tsigkey_find(&tsigkey, name, &tkeyin->algorithm, ring);
if (result != ISC_R_SUCCESS) {
tkeyout->error = dns_tsigerror_badname;
return (ISC_R_SUCCESS);
}
/*
* Only allow a delete if the identity that created the key is the
* same as the identity that signed the message.
*/
identity = dns_tsigkey_identity(tsigkey);
if (identity == NULL || !dns_name_equal(identity, signer)) {
dns_tsigkey_detach(&tsigkey);
return (DNS_R_REFUSED);
}
/*
* Set the key to be deleted when no references are left. If the key
* was not generated with TKEY and is in the config file, it may be
* reloaded later.
*/
dns_tsigkey_setdeleted(tsigkey);
/* Release the reference */
dns_tsigkey_detach(&tsigkey);
return (ISC_R_SUCCESS);
}
isc_result_t
dns_tsig_verify(isc_buffer_t *source, dns_message_t *msg,
dns_tsig_keyring_t *ring1, dns_tsig_keyring_t *ring2)
{
dns_rdata_any_tsig_t tsig, querytsig;
isc_region_t r, source_r, header_r, sig_r;
isc_buffer_t databuf;
unsigned char data[32];
dns_name_t *keyname;
dns_rdata_t rdata = DNS_RDATA_INIT;
isc_stdtime_t now;
isc_result_t ret;
dns_tsigkey_t *tsigkey;
dst_key_t *key = NULL;
unsigned char header[DNS_MESSAGE_HEADERLEN];
dst_context_t *ctx = NULL;
isc_mem_t *mctx;
isc_uint16_t addcount, id;
unsigned int siglen;
unsigned int alg;
isc_boolean_t response;
REQUIRE(source != NULL);
REQUIRE(DNS_MESSAGE_VALID(msg));
tsigkey = dns_message_gettsigkey(msg);
response = is_response(msg);
REQUIRE(tsigkey == NULL || VALID_TSIG_KEY(tsigkey));
msg->verify_attempted = 1;
if (msg->tcp_continuation) {
if (tsigkey == NULL || msg->querytsig == NULL)
return (DNS_R_UNEXPECTEDTSIG);
return (tsig_verify_tcp(source, msg));
}
/*
* There should be a TSIG record...
*/
if (msg->tsig == NULL)
return (DNS_R_EXPECTEDTSIG);
/*
* If this is a response and there's no key or query TSIG, there
* shouldn't be one on the response.
*/
if (response && (tsigkey == NULL || msg->querytsig == NULL))
return (DNS_R_UNEXPECTEDTSIG);
mctx = msg->mctx;
/*
* If we're here, we know the message is well formed and contains a
* TSIG record.
*/
keyname = msg->tsigname;
ret = dns_rdataset_first(msg->tsig);
if (ret != ISC_R_SUCCESS)
return (ret);
dns_rdataset_current(msg->tsig, &rdata);
ret = dns_rdata_tostruct(&rdata, &tsig, NULL);
if (ret != ISC_R_SUCCESS)
return (ret);
dns_rdata_reset(&rdata);
if (response) {
ret = dns_rdataset_first(msg->querytsig);
if (ret != ISC_R_SUCCESS)
return (ret);
dns_rdataset_current(msg->querytsig, &rdata);
ret = dns_rdata_tostruct(&rdata, &querytsig, NULL);
if (ret != ISC_R_SUCCESS)
return (ret);
}
#if defined(__clang__) && \
( __clang_major__ < 3 || \
(__clang_major__ == 3 && __clang_minor__ < 2) || \
(__clang_major__ == 4 && __clang_minor__ < 2))
/* false positive: http://llvm.org/bugs/show_bug.cgi?id=14461 */
else memset(&querytsig, 0, sizeof(querytsig));
#endif
/*
* Do the key name and algorithm match that of the query?
*/
if (response &&
(!dns_name_equal(keyname, &tsigkey->name) ||
!dns_name_equal(&tsig.algorithm, &querytsig.algorithm))) {
msg->tsigstatus = dns_tsigerror_badkey;
tsig_log(msg->tsigkey, 2,
"key name and algorithm do not match");
return (DNS_R_TSIGVERIFYFAILURE);
}
/*
* Get the current time.
*/
isc_stdtime_get(&now);
/*
* Find dns_tsigkey_t based on keyname.
*/
if (tsigkey == NULL) {
ret = ISC_R_NOTFOUND;
if (ring1 != NULL)
ret = dns_tsigkey_find(&tsigkey, keyname,
&tsig.algorithm, ring1);
if (ret == ISC_R_NOTFOUND && ring2 != NULL)
ret = dns_tsigkey_find(&tsigkey, keyname,
&tsig.algorithm, ring2);
if (ret != ISC_R_SUCCESS) {
msg->tsigstatus = dns_tsigerror_badkey;
ret = dns_tsigkey_create(keyname, &tsig.algorithm,
NULL, 0, ISC_FALSE, NULL,
now, now,
mctx, NULL, &msg->tsigkey);
if (ret != ISC_R_SUCCESS)
return (ret);
tsig_log(msg->tsigkey, 2, "unknown key");
return (DNS_R_TSIGVERIFYFAILURE);
}
msg->tsigkey = tsigkey;
}
key = tsigkey->key;
/*
* Is the time ok?
*/
if (now + msg->timeadjust > tsig.timesigned + tsig.fudge) {
msg->tsigstatus = dns_tsigerror_badtime;
tsig_log(msg->tsigkey, 2, "signature has expired");
return (DNS_R_CLOCKSKEW);
} else if (now + msg->timeadjust < tsig.timesigned - tsig.fudge) {
msg->tsigstatus = dns_tsigerror_badtime;
tsig_log(msg->tsigkey, 2, "signature is in the future");
return (DNS_R_CLOCKSKEW);
}
/*
* Check digest length.
*/
alg = dst_key_alg(key);
ret = dst_key_sigsize(key, &siglen);
if (ret != ISC_R_SUCCESS)
return (ret);
if (alg == DST_ALG_HMACMD5 || alg == DST_ALG_HMACSHA1 ||
alg == DST_ALG_HMACSHA224 || alg == DST_ALG_HMACSHA256 ||
alg == DST_ALG_HMACSHA384 || alg == DST_ALG_HMACSHA512) {
isc_uint16_t digestbits = dst_key_getbits(key);
if (tsig.siglen > siglen) {
tsig_log(msg->tsigkey, 2, "signature length too big");
return (DNS_R_FORMERR);
}
if (tsig.siglen > 0 &&
(tsig.siglen < 10 || tsig.siglen < ((siglen + 1) / 2))) {
tsig_log(msg->tsigkey, 2,
"signature length below minimum");
return (DNS_R_FORMERR);
}
if (tsig.siglen > 0 && digestbits != 0 &&
tsig.siglen < ((digestbits + 1) / 8)) {
msg->tsigstatus = dns_tsigerror_badtrunc;
tsig_log(msg->tsigkey, 2,
"truncated signature length too small");
return (DNS_R_TSIGVERIFYFAILURE);
}
if (tsig.siglen > 0 && digestbits == 0 &&
tsig.siglen < siglen) {
msg->tsigstatus = dns_tsigerror_badtrunc;
tsig_log(msg->tsigkey, 2, "signature length too small");
return (DNS_R_TSIGVERIFYFAILURE);
}
}
if (tsig.siglen > 0) {
sig_r.base = tsig.signature;
sig_r.length = tsig.siglen;
ret = dst_context_create3(key, mctx,
DNS_LOGCATEGORY_DNSSEC,
ISC_FALSE, &ctx);
if (ret != ISC_R_SUCCESS)
return (ret);
if (response) {
isc_buffer_init(&databuf, data, sizeof(data));
isc_buffer_putuint16(&databuf, querytsig.siglen);
isc_buffer_usedregion(&databuf, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
if (querytsig.siglen > 0) {
r.length = querytsig.siglen;
r.base = querytsig.signature;
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
}
}
/*
* Extract the header.
*/
isc_buffer_usedregion(source, &r);
memmove(header, r.base, DNS_MESSAGE_HEADERLEN);
isc_region_consume(&r, DNS_MESSAGE_HEADERLEN);
/*
* Decrement the additional field counter.
*/
memmove(&addcount, &header[DNS_MESSAGE_HEADERLEN - 2], 2);
addcount = htons((isc_uint16_t)(ntohs(addcount) - 1));
memmove(&header[DNS_MESSAGE_HEADERLEN - 2], &addcount, 2);
/*
* Put in the original id.
*/
id = htons(tsig.originalid);
memmove(&header[0], &id, 2);
/*
* Digest the modified header.
*/
header_r.base = (unsigned char *) header;
header_r.length = DNS_MESSAGE_HEADERLEN;
ret = dst_context_adddata(ctx, &header_r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
/*
* Digest all non-TSIG records.
*/
isc_buffer_usedregion(source, &source_r);
r.base = source_r.base + DNS_MESSAGE_HEADERLEN;
r.length = msg->sigstart - DNS_MESSAGE_HEADERLEN;
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
/*
* Digest the key name.
*/
dns_name_toregion(&tsigkey->name, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
isc_buffer_init(&databuf, data, sizeof(data));
isc_buffer_putuint16(&databuf, tsig.common.rdclass);
isc_buffer_putuint32(&databuf, msg->tsig->ttl);
isc_buffer_usedregion(&databuf, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
/*
* Digest the key algorithm.
*/
dns_name_toregion(tsigkey->algorithm, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
isc_buffer_clear(&databuf);
isc_buffer_putuint48(&databuf, tsig.timesigned);
isc_buffer_putuint16(&databuf, tsig.fudge);
isc_buffer_putuint16(&databuf, tsig.error);
isc_buffer_putuint16(&databuf, tsig.otherlen);
isc_buffer_usedregion(&databuf, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
if (tsig.otherlen > 0) {
r.base = tsig.other;
r.length = tsig.otherlen;
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
}
ret = dst_context_verify(ctx, &sig_r);
if (ret == DST_R_VERIFYFAILURE) {
msg->tsigstatus = dns_tsigerror_badsig;
ret = DNS_R_TSIGVERIFYFAILURE;
tsig_log(msg->tsigkey, 2,
"signature failed to verify(1)");
goto cleanup_context;
} else if (ret != ISC_R_SUCCESS)
goto cleanup_context;
dst_context_destroy(&ctx);
} else if (tsig.error != dns_tsigerror_badsig &&
tsig.error != dns_tsigerror_badkey) {
msg->tsigstatus = dns_tsigerror_badsig;
tsig_log(msg->tsigkey, 2, "signature was empty");
return (DNS_R_TSIGVERIFYFAILURE);
}
msg->tsigstatus = dns_rcode_noerror;
if (tsig.error != dns_rcode_noerror) {
if (tsig.error == dns_tsigerror_badtime)
return (DNS_R_CLOCKSKEW);
else
return (DNS_R_TSIGERRORSET);
}
msg->verified_sig = 1;
return (ISC_R_SUCCESS);
cleanup_context:
if (ctx != NULL)
dst_context_destroy(&ctx);
return (ret);
}
isc_result_t
dns_tkey_processquery(dns_message_t *msg, dns_tkeyctx_t *tctx,
dns_tsig_keyring_t *ring)
{
isc_result_t result = ISC_R_SUCCESS;
dns_rdata_tkey_t tkeyin, tkeyout;
isc_boolean_t freetkeyin = ISC_FALSE;
dns_name_t *qname, *name, *keyname, *signer, tsigner;
dns_fixedname_t fkeyname;
dns_rdataset_t *tkeyset;
dns_rdata_t rdata;
dns_namelist_t namelist;
char tkeyoutdata[512];
isc_buffer_t tkeyoutbuf;
REQUIRE(msg != NULL);
REQUIRE(tctx != NULL);
REQUIRE(ring != NULL);
ISC_LIST_INIT(namelist);
/*
* Interpret the question section.
*/
result = dns_message_firstname(msg, DNS_SECTION_QUESTION);
if (result != ISC_R_SUCCESS)
return (DNS_R_FORMERR);
qname = NULL;
dns_message_currentname(msg, DNS_SECTION_QUESTION, &qname);
/*
* Look for a TKEY record that matches the question.
*/
tkeyset = NULL;
name = NULL;
result = dns_message_findname(msg, DNS_SECTION_ADDITIONAL, qname,
dns_rdatatype_tkey, 0, &name, &tkeyset);
if (result != ISC_R_SUCCESS) {
/*
* Try the answer section, since that's where Win2000
* puts it.
*/
name = NULL;
if (dns_message_findname(msg, DNS_SECTION_ANSWER, qname,
dns_rdatatype_tkey, 0, &name,
&tkeyset) != ISC_R_SUCCESS) {
result = DNS_R_FORMERR;
tkey_log("dns_tkey_processquery: couldn't find a TKEY "
"matching the question");
goto failure;
}
}
result = dns_rdataset_first(tkeyset);
if (result != ISC_R_SUCCESS) {
result = DNS_R_FORMERR;
goto failure;
}
dns_rdata_init(&rdata);
dns_rdataset_current(tkeyset, &rdata);
RETERR(dns_rdata_tostruct(&rdata, &tkeyin, NULL));
freetkeyin = ISC_TRUE;
if (tkeyin.error != dns_rcode_noerror) {
result = DNS_R_FORMERR;
goto failure;
}
/*
* Before we go any farther, verify that the message was signed.
* GSSAPI TKEY doesn't require a signature, the rest do.
*/
dns_name_init(&tsigner, NULL);
result = dns_message_signer(msg, &tsigner);
if (result != ISC_R_SUCCESS) {
if (tkeyin.mode == DNS_TKEYMODE_GSSAPI &&
result == ISC_R_NOTFOUND)
signer = NULL;
else {
tkey_log("dns_tkey_processquery: query was not "
"properly signed - rejecting");
result = DNS_R_FORMERR;
goto failure;
}
} else
signer = &tsigner;
tkeyout.common.rdclass = tkeyin.common.rdclass;
tkeyout.common.rdtype = tkeyin.common.rdtype;
ISC_LINK_INIT(&tkeyout.common, link);
tkeyout.mctx = msg->mctx;
dns_name_init(&tkeyout.algorithm, NULL);
dns_name_clone(&tkeyin.algorithm, &tkeyout.algorithm);
tkeyout.inception = tkeyout.expire = 0;
tkeyout.mode = tkeyin.mode;
tkeyout.error = 0;
tkeyout.keylen = tkeyout.otherlen = 0;
tkeyout.key = tkeyout.other = NULL;
/*
* A delete operation must have a fully specified key name. If this
* is not a delete, we do the following:
* if (qname != ".")
* keyname = qname + defaultdomain
* else
* keyname = <random hex> + defaultdomain
*/
if (tkeyin.mode != DNS_TKEYMODE_DELETE) {
dns_tsigkey_t *tsigkey = NULL;
if (tctx->domain == NULL && tkeyin.mode != DNS_TKEYMODE_GSSAPI) {
tkey_log("dns_tkey_processquery: tkey-domain not set");
result = DNS_R_REFUSED;
goto failure;
}
dns_fixedname_init(&fkeyname);
keyname = dns_fixedname_name(&fkeyname);
if (!dns_name_equal(qname, dns_rootname)) {
unsigned int n = dns_name_countlabels(qname);
RUNTIME_CHECK(dns_name_copy(qname, keyname, NULL)
== ISC_R_SUCCESS);
dns_name_getlabelsequence(keyname, 0, n - 1, keyname);
} else {
static char hexdigits[16] = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
unsigned char randomdata[16];
char randomtext[32];
isc_buffer_t b;
unsigned int i, j;
result = isc_entropy_getdata(tctx->ectx,
randomdata,
sizeof(randomdata),
NULL, 0);
if (result != ISC_R_SUCCESS)
goto failure;
for (i = 0, j = 0; i < sizeof(randomdata); i++) {
unsigned char val = randomdata[i];
randomtext[j++] = hexdigits[val >> 4];
randomtext[j++] = hexdigits[val & 0xF];
}
isc_buffer_init(&b, randomtext, sizeof(randomtext));
isc_buffer_add(&b, sizeof(randomtext));
result = dns_name_fromtext(keyname, &b, NULL, 0, NULL);
if (result != ISC_R_SUCCESS)
goto failure;
}
if (tkeyin.mode == DNS_TKEYMODE_GSSAPI) {
/* Yup. This is a hack */
result = dns_name_concatenate(keyname, dns_rootname,
keyname, NULL);
if (result != ISC_R_SUCCESS)
goto failure;
} else {
result = dns_name_concatenate(keyname, tctx->domain,
keyname, NULL);
if (result != ISC_R_SUCCESS)
goto failure;
}
result = dns_tsigkey_find(&tsigkey, keyname, NULL, ring);
if (result == ISC_R_SUCCESS) {
tkeyout.error = dns_tsigerror_badname;
dns_tsigkey_detach(&tsigkey);
goto failure_with_tkey;
} else if (result != ISC_R_NOTFOUND)
goto failure;
} else
static isc_result_t
process_gsstkey(dns_name_t *name, dns_rdata_tkey_t *tkeyin,
dns_tkeyctx_t *tctx, dns_rdata_tkey_t *tkeyout,
dns_tsig_keyring_t *ring)
{
isc_result_t result = ISC_R_SUCCESS;
dst_key_t *dstkey = NULL;
dns_tsigkey_t *tsigkey = NULL;
dns_fixedname_t principal;
isc_stdtime_t now;
isc_region_t intoken;
isc_buffer_t *outtoken = NULL;
gss_ctx_id_t gss_ctx = NULL;
/*
* You have to define either a gss credential (principal) to
* accept with tkey-gssapi-credential, or you have to
* configure a specific keytab (with tkey-gssapi-keytab) in
* order to use gsstkey
*/
if (tctx->gsscred == NULL && tctx->gssapi_keytab == NULL) {
tkey_log("process_gsstkey(): no tkey-gssapi-credential "
"or tkey-gssapi-keytab configured");
return (ISC_R_NOPERM);
}
if (!dns_name_equal(&tkeyin->algorithm, DNS_TSIG_GSSAPI_NAME) &&
!dns_name_equal(&tkeyin->algorithm, DNS_TSIG_GSSAPIMS_NAME)) {
tkeyout->error = dns_tsigerror_badalg;
tkey_log("process_gsstkey(): dns_tsigerror_badalg"); /* XXXSRA */
return (ISC_R_SUCCESS);
}
/*
* XXXDCL need to check for key expiry per 4.1.1
* XXXDCL need a way to check fully established, perhaps w/key_flags
*/
intoken.base = tkeyin->key;
intoken.length = tkeyin->keylen;
result = dns_tsigkey_find(&tsigkey, name, &tkeyin->algorithm, ring);
if (result == ISC_R_SUCCESS)
gss_ctx = dst_key_getgssctx(tsigkey->key);
dns_fixedname_init(&principal);
/*
* Note that tctx->gsscred may be NULL if tctx->gssapi_keytab is set
*/
result = dst_gssapi_acceptctx(tctx->gsscred, tctx->gssapi_keytab,
&intoken,
&outtoken, &gss_ctx,
dns_fixedname_name(&principal),
tctx->mctx);
if (result == DNS_R_INVALIDTKEY) {
if (tsigkey != NULL)
dns_tsigkey_detach(&tsigkey);
tkeyout->error = dns_tsigerror_badkey;
tkey_log("process_gsstkey(): dns_tsigerror_badkey"); /* XXXSRA */
return (ISC_R_SUCCESS);
}
if (result != DNS_R_CONTINUE && result != ISC_R_SUCCESS)
goto failure;
/*
* XXXDCL Section 4.1.3: Limit GSS_S_CONTINUE_NEEDED to 10 times.
*/
isc_stdtime_get(&now);
if (tsigkey == NULL) {
#ifdef GSSAPI
OM_uint32 gret, minor, lifetime;
#endif
isc_uint32_t expire;
RETERR(dst_key_fromgssapi(name, gss_ctx, ring->mctx,
&dstkey, &intoken));
/*
* Limit keys to 1 hour or the context's lifetime whichever
* is smaller.
*/
expire = now + 3600;
#ifdef GSSAPI
gret = gss_context_time(&minor, gss_ctx, &lifetime);
if (gret == GSS_S_COMPLETE && now + lifetime < expire)
expire = now + lifetime;
#endif
RETERR(dns_tsigkey_createfromkey(name, &tkeyin->algorithm,
dstkey, ISC_TRUE,
dns_fixedname_name(&principal),
now, expire, ring->mctx, ring,
NULL));
dst_key_free(&dstkey);
tkeyout->inception = now;
tkeyout->expire = expire;
} else {
tkeyout->inception = tsigkey->inception;
tkeyout->expire = tsigkey->expire;
dns_tsigkey_detach(&tsigkey);
}
if (outtoken) {
tkeyout->key = isc_mem_get(tkeyout->mctx,
isc_buffer_usedlength(outtoken));
if (tkeyout->key == NULL) {
result = ISC_R_NOMEMORY;
goto failure;
}
tkeyout->keylen = isc_buffer_usedlength(outtoken);
memmove(tkeyout->key, isc_buffer_base(outtoken),
isc_buffer_usedlength(outtoken));
isc_buffer_free(&outtoken);
} else {
tkeyout->key = isc_mem_get(tkeyout->mctx, tkeyin->keylen);
if (tkeyout->key == NULL) {
result = ISC_R_NOMEMORY;
goto failure;
}
tkeyout->keylen = tkeyin->keylen;
memmove(tkeyout->key, tkeyin->key, tkeyin->keylen);
}
tkeyout->error = dns_rcode_noerror;
tkey_log("process_gsstkey(): dns_tsigerror_noerror"); /* XXXSRA */
return (ISC_R_SUCCESS);
failure:
if (tsigkey != NULL)
dns_tsigkey_detach(&tsigkey);
if (dstkey != NULL)
dst_key_free(&dstkey);
if (outtoken != NULL)
isc_buffer_free(&outtoken);
tkey_log("process_gsstkey(): %s",
isc_result_totext(result)); /* XXXSRA */
return (result);
}