isc_result_t
dns_tsig_sign(dns_message_t *msg) {
dns_tsigkey_t *key;
dns_rdata_any_tsig_t tsig, querytsig;
unsigned char data[128];
isc_buffer_t databuf, sigbuf;
isc_buffer_t *dynbuf;
dns_name_t *owner;
dns_rdata_t *rdata = NULL;
dns_rdatalist_t *datalist;
dns_rdataset_t *dataset;
isc_region_t r;
isc_stdtime_t now;
isc_mem_t *mctx;
dst_context_t *ctx = NULL;
isc_result_t ret;
unsigned char badtimedata[BADTIMELEN];
unsigned int sigsize = 0;
isc_boolean_t response = is_response(msg);
REQUIRE(msg != NULL);
REQUIRE(VALID_TSIG_KEY(dns_message_gettsigkey(msg)));
/*
* If this is a response, there should be a query tsig.
*/
if (response && msg->querytsig == NULL)
return (DNS_R_EXPECTEDTSIG);
dynbuf = NULL;
mctx = msg->mctx;
key = dns_message_gettsigkey(msg);
tsig.mctx = mctx;
tsig.common.rdclass = dns_rdataclass_any;
tsig.common.rdtype = dns_rdatatype_tsig;
ISC_LINK_INIT(&tsig.common, link);
dns_name_init(&tsig.algorithm, NULL);
dns_name_clone(key->algorithm, &tsig.algorithm);
isc_stdtime_get(&now);
tsig.timesigned = now + msg->timeadjust;
tsig.fudge = DNS_TSIG_FUDGE;
tsig.originalid = msg->id;
isc_buffer_init(&databuf, data, sizeof(data));
if (response)
tsig.error = msg->querytsigstatus;
else
tsig.error = dns_rcode_noerror;
if (tsig.error != dns_tsigerror_badtime) {
tsig.otherlen = 0;
tsig.other = NULL;
} else {
isc_buffer_t otherbuf;
tsig.otherlen = BADTIMELEN;
tsig.other = badtimedata;
isc_buffer_init(&otherbuf, tsig.other, tsig.otherlen);
isc_buffer_putuint48(&otherbuf, tsig.timesigned);
}
if (key->key != NULL && tsig.error != dns_tsigerror_badsig) {
unsigned char header[DNS_MESSAGE_HEADERLEN];
isc_buffer_t headerbuf;
isc_uint16_t digestbits;
ret = dst_context_create3(key->key, mctx,
DNS_LOGCATEGORY_DNSSEC,
ISC_TRUE, &ctx);
if (ret != ISC_R_SUCCESS)
return (ret);
/*
* If this is a response, digest the query signature.
*/
if (response) {
dns_rdata_t querytsigrdata = DNS_RDATA_INIT;
ret = dns_rdataset_first(msg->querytsig);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
dns_rdataset_current(msg->querytsig, &querytsigrdata);
ret = dns_rdata_tostruct(&querytsigrdata, &querytsig,
NULL);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
isc_buffer_putuint16(&databuf, querytsig.siglen);
if (isc_buffer_availablelength(&databuf) <
querytsig.siglen) {
ret = ISC_R_NOSPACE;
goto cleanup_context;
}
isc_buffer_putmem(&databuf, querytsig.signature,
querytsig.siglen);
isc_buffer_usedregion(&databuf, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
}
#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
/*
* Digest the header.
*/
isc_buffer_init(&headerbuf, header, sizeof(header));
dns_message_renderheader(msg, &headerbuf);
isc_buffer_usedregion(&headerbuf, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
/*
* Digest the remainder of the message.
*/
isc_buffer_usedregion(msg->buffer, &r);
isc_region_consume(&r, DNS_MESSAGE_HEADERLEN);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
if (msg->tcp_continuation == 0) {
/*
* Digest the name, class, ttl, alg.
*/
dns_name_toregion(&key->name, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
isc_buffer_clear(&databuf);
isc_buffer_putuint16(&databuf, dns_rdataclass_any);
isc_buffer_putuint32(&databuf, 0); /* ttl */
isc_buffer_usedregion(&databuf, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
dns_name_toregion(&tsig.algorithm, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
}
/* Digest the timesigned and fudge */
isc_buffer_clear(&databuf);
if (tsig.error == dns_tsigerror_badtime) {
INSIST(response);
tsig.timesigned = querytsig.timesigned;
}
isc_buffer_putuint48(&databuf, tsig.timesigned);
isc_buffer_putuint16(&databuf, tsig.fudge);
isc_buffer_usedregion(&databuf, &r);
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
if (msg->tcp_continuation == 0) {
/*
* Digest the error and other data length.
*/
isc_buffer_clear(&databuf);
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;
/*
* Digest other data.
*/
if (tsig.otherlen > 0) {
r.length = tsig.otherlen;
r.base = tsig.other;
ret = dst_context_adddata(ctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
}
}
ret = dst_key_sigsize(key->key, &sigsize);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
tsig.signature = (unsigned char *) isc_mem_get(mctx, sigsize);
if (tsig.signature == NULL) {
ret = ISC_R_NOMEMORY;
goto cleanup_context;
}
isc_buffer_init(&sigbuf, tsig.signature, sigsize);
ret = dst_context_sign(ctx, &sigbuf);
if (ret != ISC_R_SUCCESS)
goto cleanup_signature;
dst_context_destroy(&ctx);
digestbits = dst_key_getbits(key->key);
if (digestbits != 0) {
unsigned int bytes = (digestbits + 1) / 8;
if (response && bytes < querytsig.siglen)
bytes = querytsig.siglen;
if (bytes > isc_buffer_usedlength(&sigbuf))
bytes = isc_buffer_usedlength(&sigbuf);
tsig.siglen = bytes;
} else
tsig.siglen = isc_buffer_usedlength(&sigbuf);
} else {
tsig.siglen = 0;
tsig.signature = NULL;
}
ret = dns_message_gettemprdata(msg, &rdata);
if (ret != ISC_R_SUCCESS)
goto cleanup_signature;
ret = isc_buffer_allocate(msg->mctx, &dynbuf, 512);
if (ret != ISC_R_SUCCESS)
goto cleanup_rdata;
ret = dns_rdata_fromstruct(rdata, dns_rdataclass_any,
dns_rdatatype_tsig, &tsig, dynbuf);
if (ret != ISC_R_SUCCESS)
goto cleanup_dynbuf;
dns_message_takebuffer(msg, &dynbuf);
if (tsig.signature != NULL) {
isc_mem_put(mctx, tsig.signature, sigsize);
tsig.signature = NULL;
}
owner = NULL;
ret = dns_message_gettempname(msg, &owner);
if (ret != ISC_R_SUCCESS)
goto cleanup_rdata;
dns_name_init(owner, NULL);
ret = dns_name_dup(&key->name, msg->mctx, owner);
if (ret != ISC_R_SUCCESS)
goto cleanup_owner;
datalist = NULL;
ret = dns_message_gettemprdatalist(msg, &datalist);
if (ret != ISC_R_SUCCESS)
goto cleanup_owner;
dataset = NULL;
ret = dns_message_gettemprdataset(msg, &dataset);
if (ret != ISC_R_SUCCESS)
goto cleanup_rdatalist;
datalist->rdclass = dns_rdataclass_any;
datalist->type = dns_rdatatype_tsig;
datalist->covers = 0;
datalist->ttl = 0;
ISC_LIST_INIT(datalist->rdata);
ISC_LIST_APPEND(datalist->rdata, rdata, link);
RUNTIME_CHECK(dns_rdatalist_tordataset(datalist, dataset)
== ISC_R_SUCCESS);
msg->tsig = dataset;
msg->tsigname = owner;
/* Windows does not like the tsig name being compressed. */
msg->tsigname->attributes |= DNS_NAMEATTR_NOCOMPRESS;
return (ISC_R_SUCCESS);
cleanup_rdatalist:
dns_message_puttemprdatalist(msg, &datalist);
cleanup_owner:
dns_message_puttempname(msg, &owner);
goto cleanup_rdata;
cleanup_dynbuf:
isc_buffer_free(&dynbuf);
cleanup_rdata:
dns_message_puttemprdata(msg, &rdata);
cleanup_signature:
if (tsig.signature != NULL)
isc_mem_put(mctx, tsig.signature, sigsize);
cleanup_context:
if (ctx != NULL)
dst_context_destroy(&ctx);
return (ret);
}
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);
}
static isc_result_t
tsig_verify_tcp(isc_buffer_t *source, dns_message_t *msg) {
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];
isc_uint16_t addcount, id;
isc_boolean_t has_tsig = ISC_FALSE;
isc_mem_t *mctx;
REQUIRE(source != NULL);
REQUIRE(msg != NULL);
REQUIRE(dns_message_gettsigkey(msg) != NULL);
REQUIRE(msg->tcp_continuation == 1);
REQUIRE(msg->querytsig != NULL);
if (!is_response(msg))
return (DNS_R_EXPECTEDRESPONSE);
mctx = msg->mctx;
tsigkey = dns_message_gettsigkey(msg);
/*
* Extract and parse the previous TSIG
*/
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);
dns_rdata_reset(&rdata);
/*
* If there is a TSIG in this message, do some checks.
*/
if (msg->tsig != NULL) {
has_tsig = ISC_TRUE;
keyname = msg->tsigname;
ret = dns_rdataset_first(msg->tsig);
if (ret != ISC_R_SUCCESS)
goto cleanup_querystruct;
dns_rdataset_current(msg->tsig, &rdata);
ret = dns_rdata_tostruct(&rdata, &tsig, NULL);
if (ret != ISC_R_SUCCESS)
goto cleanup_querystruct;
/*
* Do the key name and algorithm match that of the query?
*/
if (!dns_name_equal(keyname, &tsigkey->name) ||
!dns_name_equal(&tsig.algorithm, &querytsig.algorithm)) {
msg->tsigstatus = dns_tsigerror_badkey;
ret = DNS_R_TSIGVERIFYFAILURE;
tsig_log(msg->tsigkey, 2,
"key name and algorithm do not match");
goto cleanup_querystruct;
}
/*
* Is the time ok?
*/
isc_stdtime_get(&now);
if (now + msg->timeadjust > tsig.timesigned + tsig.fudge) {
msg->tsigstatus = dns_tsigerror_badtime;
tsig_log(msg->tsigkey, 2, "signature has expired");
ret = DNS_R_CLOCKSKEW;
goto cleanup_querystruct;
} else if (now + msg->timeadjust <
tsig.timesigned - tsig.fudge) {
msg->tsigstatus = dns_tsigerror_badtime;
tsig_log(msg->tsigkey, 2,
"signature is in the future");
ret = DNS_R_CLOCKSKEW;
goto cleanup_querystruct;
}
}
key = tsigkey->key;
if (msg->tsigctx == NULL) {
ret = dst_context_create3(key, mctx,
DNS_LOGCATEGORY_DNSSEC,
ISC_FALSE, &msg->tsigctx);
if (ret != ISC_R_SUCCESS)
goto cleanup_querystruct;
/*
* Digest the length of the query signature
*/
isc_buffer_init(&databuf, data, sizeof(data));
isc_buffer_putuint16(&databuf, querytsig.siglen);
isc_buffer_usedregion(&databuf, &r);
ret = dst_context_adddata(msg->tsigctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
/*
* Digest the data of the query signature
*/
if (querytsig.siglen > 0) {
r.length = querytsig.siglen;
r.base = querytsig.signature;
ret = dst_context_adddata(msg->tsigctx, &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 if necessary.
*/
if (has_tsig) {
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.
*/
/* XXX Can TCP transfers be forwarded? How would that work? */
if (has_tsig) {
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(msg->tsigctx, &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;
if (has_tsig)
r.length = msg->sigstart - DNS_MESSAGE_HEADERLEN;
else
r.length = source_r.length - DNS_MESSAGE_HEADERLEN;
ret = dst_context_adddata(msg->tsigctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
/*
* Digest the time signed and fudge.
*/
if (has_tsig) {
isc_buffer_init(&databuf, data, sizeof(data));
isc_buffer_putuint48(&databuf, tsig.timesigned);
isc_buffer_putuint16(&databuf, tsig.fudge);
isc_buffer_usedregion(&databuf, &r);
ret = dst_context_adddata(msg->tsigctx, &r);
if (ret != ISC_R_SUCCESS)
goto cleanup_context;
sig_r.base = tsig.signature;
sig_r.length = tsig.siglen;
if (tsig.siglen == 0) {
if (tsig.error != dns_rcode_noerror) {
if (tsig.error == dns_tsigerror_badtime)
ret = DNS_R_CLOCKSKEW;
else
ret = DNS_R_TSIGERRORSET;
} else {
tsig_log(msg->tsigkey, 2,
"signature is empty");
ret = DNS_R_TSIGVERIFYFAILURE;
}
goto cleanup_context;
}
ret = dst_context_verify(msg->tsigctx, &sig_r);
if (ret == DST_R_VERIFYFAILURE) {
msg->tsigstatus = dns_tsigerror_badsig;
tsig_log(msg->tsigkey, 2,
"signature failed to verify(2)");
ret = DNS_R_TSIGVERIFYFAILURE;
goto cleanup_context;
}
else if (ret != ISC_R_SUCCESS)
goto cleanup_context;
dst_context_destroy(&msg->tsigctx);
}
msg->tsigstatus = dns_rcode_noerror;
return (ISC_R_SUCCESS);
cleanup_context:
dst_context_destroy(&msg->tsigctx);
cleanup_querystruct:
dns_rdata_freestruct(&querytsig);
return (ret);
}
static isc_result_t
add_tsig(dst_context_t *tsigctx, dns_tsigkey_t *key, isc_buffer_t *target) {
dns_compress_t cctx;
dns_rdata_any_tsig_t tsig;
dns_rdata_t rdata = DNS_RDATA_INIT;
dns_rdatalist_t rdatalist;
dns_rdataset_t rdataset;
isc_buffer_t *dynbuf = NULL;
isc_buffer_t databuf;
isc_buffer_t sigbuf;
isc_region_t r;
isc_result_t result = ISC_R_SUCCESS;
isc_stdtime_t now;
unsigned char tsigbuf[1024];
unsigned int count;
unsigned int sigsize;
isc_boolean_t invalidate_ctx = ISC_FALSE;
CHECK(dns_compress_init(&cctx, -1, mctx));
invalidate_ctx = ISC_TRUE;
memset(&tsig, 0, sizeof(tsig));
tsig.common.rdclass = dns_rdataclass_any;
tsig.common.rdtype = dns_rdatatype_tsig;
ISC_LINK_INIT(&tsig.common, link);
dns_name_init(&tsig.algorithm, NULL);
dns_name_clone(key->algorithm, &tsig.algorithm);
isc_stdtime_get(&now);
tsig.timesigned = now;
tsig.fudge = DNS_TSIG_FUDGE;
tsig.originalid = 50;
tsig.error = dns_rcode_noerror;
tsig.otherlen = 0;
tsig.other = NULL;
isc_buffer_init(&databuf, tsigbuf, sizeof(tsigbuf));
isc_buffer_putuint48(&databuf, tsig.timesigned);
isc_buffer_putuint16(&databuf, tsig.fudge);
isc_buffer_usedregion(&databuf, &r);
CHECK(dst_context_adddata(tsigctx, &r));
CHECK(dst_key_sigsize(key->key, &sigsize));
tsig.signature = (unsigned char *) isc_mem_get(mctx, sigsize);
if (tsig.signature == NULL)
CHECK(ISC_R_NOMEMORY);
isc_buffer_init(&sigbuf, tsig.signature, sigsize);
CHECK(dst_context_sign(tsigctx, &sigbuf));
tsig.siglen = isc_buffer_usedlength(&sigbuf);
CHECK(isc_buffer_allocate(mctx, &dynbuf, 512));
CHECK(dns_rdata_fromstruct(&rdata, dns_rdataclass_any,
dns_rdatatype_tsig, &tsig, dynbuf));
dns_rdatalist_init(&rdatalist);
rdatalist.rdclass = dns_rdataclass_any;
rdatalist.type = dns_rdatatype_tsig;
ISC_LIST_APPEND(rdatalist.rdata, &rdata, link);
dns_rdataset_init(&rdataset);
CHECK(dns_rdatalist_tordataset(&rdatalist, &rdataset));
CHECK(dns_rdataset_towire(&rdataset, &key->name, &cctx,
target, 0, &count));
/*
* Fixup additional record count.
*/
((unsigned char*)target->base)[11]++;
if (((unsigned char*)target->base)[11] == 0)
((unsigned char*)target->base)[10]++;
cleanup:
if (tsig.signature != NULL)
isc_mem_put(mctx, tsig.signature, sigsize);
if (dynbuf != NULL)
isc_buffer_free(&dynbuf);
if (invalidate_ctx)
dns_compress_invalidate(&cctx);
return (result);
}