/* * Copyright (C) 2004-2007 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1999-2002 Internet Software Consortium. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */ /* * $Id: tsig.c,v 1.117.18.11 2007/09/26 23:46:34 tbox Exp $ */ /*! \file */ #include #include #include #include #include #include #include /* Required for HP/UX (and others?) */ #include #include #include #include #include #include #include #include #include #include #include #include #define TSIG_MAGIC ISC_MAGIC('T', 'S', 'I', 'G') #define VALID_TSIG_KEY(x) ISC_MAGIC_VALID(x, TSIG_MAGIC) #define is_response(msg) (msg->flags & DNS_MESSAGEFLAG_QR) #define algname_is_allocated(algname) \ ((algname) != dns_tsig_hmacmd5_name && \ (algname) != dns_tsig_hmacsha1_name && \ (algname) != dns_tsig_hmacsha224_name && \ (algname) != dns_tsig_hmacsha256_name && \ (algname) != dns_tsig_hmacsha384_name && \ (algname) != dns_tsig_hmacsha512_name && \ (algname) != dns_tsig_gssapi_name && \ (algname) != dns_tsig_gssapims_name) #define BADTIMELEN 6 static unsigned char hmacmd5_ndata[] = "\010hmac-md5\007sig-alg\003reg\003int"; static unsigned char hmacmd5_offsets[] = { 0, 9, 17, 21, 25 }; static dns_name_t hmacmd5 = { DNS_NAME_MAGIC, hmacmd5_ndata, 26, 5, DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE, hmacmd5_offsets, NULL, {(void *)-1, (void *)-1}, {NULL, NULL} }; dns_name_t *dns_tsig_hmacmd5_name = &hmacmd5; static unsigned char gsstsig_ndata[] = "\010gss-tsig"; static unsigned char gsstsig_offsets[] = { 0, 9 }; static dns_name_t gsstsig = { DNS_NAME_MAGIC, gsstsig_ndata, 10, 2, DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE, gsstsig_offsets, NULL, {(void *)-1, (void *)-1}, {NULL, NULL} }; LIBDNS_EXTERNAL_DATA dns_name_t *dns_tsig_gssapi_name = &gsstsig; /* It's nice of Microsoft to conform to their own standard. */ static unsigned char gsstsigms_ndata[] = "\003gss\011microsoft\003com"; static unsigned char gsstsigms_offsets[] = { 0, 4, 14, 18 }; static dns_name_t gsstsigms = { DNS_NAME_MAGIC, gsstsigms_ndata, 19, 4, DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE, gsstsigms_offsets, NULL, {(void *)-1, (void *)-1}, {NULL, NULL} }; LIBDNS_EXTERNAL_DATA dns_name_t *dns_tsig_gssapims_name = &gsstsigms; static unsigned char hmacsha1_ndata[] = "\011hmac-sha1"; static unsigned char hmacsha1_offsets[] = { 0, 10 }; static dns_name_t hmacsha1 = { DNS_NAME_MAGIC, hmacsha1_ndata, 11, 2, DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE, hmacsha1_offsets, NULL, {(void *)-1, (void *)-1}, {NULL, NULL} }; LIBDNS_EXTERNAL_DATA dns_name_t *dns_tsig_hmacsha1_name = &hmacsha1; static unsigned char hmacsha224_ndata[] = "\013hmac-sha224"; static unsigned char hmacsha224_offsets[] = { 0, 12 }; static dns_name_t hmacsha224 = { DNS_NAME_MAGIC, hmacsha224_ndata, 13, 2, DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE, hmacsha224_offsets, NULL, {(void *)-1, (void *)-1}, {NULL, NULL} }; LIBDNS_EXTERNAL_DATA dns_name_t *dns_tsig_hmacsha224_name = &hmacsha224; static unsigned char hmacsha256_ndata[] = "\013hmac-sha256"; static unsigned char hmacsha256_offsets[] = { 0, 12 }; static dns_name_t hmacsha256 = { DNS_NAME_MAGIC, hmacsha256_ndata, 13, 2, DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE, hmacsha256_offsets, NULL, {(void *)-1, (void *)-1}, {NULL, NULL} }; LIBDNS_EXTERNAL_DATA dns_name_t *dns_tsig_hmacsha256_name = &hmacsha256; static unsigned char hmacsha384_ndata[] = "\013hmac-sha384"; static unsigned char hmacsha384_offsets[] = { 0, 12 }; static dns_name_t hmacsha384 = { DNS_NAME_MAGIC, hmacsha384_ndata, 13, 2, DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE, hmacsha384_offsets, NULL, {(void *)-1, (void *)-1}, {NULL, NULL} }; LIBDNS_EXTERNAL_DATA dns_name_t *dns_tsig_hmacsha384_name = &hmacsha384; static unsigned char hmacsha512_ndata[] = "\013hmac-sha512"; static unsigned char hmacsha512_offsets[] = { 0, 12 }; static dns_name_t hmacsha512 = { DNS_NAME_MAGIC, hmacsha512_ndata, 13, 2, DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE, hmacsha512_offsets, NULL, {(void *)-1, (void *)-1}, {NULL, NULL} }; LIBDNS_EXTERNAL_DATA dns_name_t *dns_tsig_hmacsha512_name = &hmacsha512; static isc_result_t tsig_verify_tcp(isc_buffer_t *source, dns_message_t *msg); static void tsig_log(dns_tsigkey_t *key, int level, const char *fmt, ...) ISC_FORMAT_PRINTF(3, 4); static void tsig_log(dns_tsigkey_t *key, int level, const char *fmt, ...) { va_list ap; char message[4096]; char namestr[DNS_NAME_FORMATSIZE]; if (isc_log_wouldlog(dns_lctx, level) == ISC_FALSE) return; if (key != NULL) dns_name_format(&key->name, namestr, sizeof(namestr)); else strcpy(namestr, ""); va_start(ap, fmt); vsnprintf(message, sizeof(message), fmt, ap); va_end(ap); isc_log_write(dns_lctx, DNS_LOGCATEGORY_DNSSEC, DNS_LOGMODULE_TSIG, level, "tsig key '%s': %s", namestr, message); } isc_result_t dns_tsigkey_createfromkey(dns_name_t *name, dns_name_t *algorithm, dst_key_t *dstkey, isc_boolean_t generated, dns_name_t *creator, isc_stdtime_t inception, isc_stdtime_t expire, isc_mem_t *mctx, dns_tsig_keyring_t *ring, dns_tsigkey_t **key) { dns_tsigkey_t *tkey; isc_result_t ret; unsigned int refs = 0; REQUIRE(key == NULL || *key == NULL); REQUIRE(name != NULL); REQUIRE(algorithm != NULL); REQUIRE(mctx != NULL); REQUIRE(key != NULL || ring != NULL); tkey = (dns_tsigkey_t *) isc_mem_get(mctx, sizeof(dns_tsigkey_t)); if (tkey == NULL) return (ISC_R_NOMEMORY); dns_name_init(&tkey->name, NULL); ret = dns_name_dup(name, mctx, &tkey->name); if (ret != ISC_R_SUCCESS) goto cleanup_key; (void)dns_name_downcase(&tkey->name, &tkey->name, NULL); if (dns_name_equal(algorithm, DNS_TSIG_HMACMD5_NAME)) { tkey->algorithm = DNS_TSIG_HMACMD5_NAME; if (dstkey != NULL && dst_key_alg(dstkey) != DST_ALG_HMACMD5) { ret = DNS_R_BADALG; goto cleanup_name; } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA1_NAME)) { tkey->algorithm = DNS_TSIG_HMACSHA1_NAME; if (dstkey != NULL && dst_key_alg(dstkey) != DST_ALG_HMACSHA1) { ret = DNS_R_BADALG; goto cleanup_name; } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA224_NAME)) { tkey->algorithm = DNS_TSIG_HMACSHA224_NAME; if (dstkey != NULL && dst_key_alg(dstkey) != DST_ALG_HMACSHA224) { ret = DNS_R_BADALG; goto cleanup_name; } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA256_NAME)) { tkey->algorithm = DNS_TSIG_HMACSHA256_NAME; if (dstkey != NULL && dst_key_alg(dstkey) != DST_ALG_HMACSHA256) { ret = DNS_R_BADALG; goto cleanup_name; } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA384_NAME)) { tkey->algorithm = DNS_TSIG_HMACSHA384_NAME; if (dstkey != NULL && dst_key_alg(dstkey) != DST_ALG_HMACSHA384) { ret = DNS_R_BADALG; goto cleanup_name; } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA512_NAME)) { tkey->algorithm = DNS_TSIG_HMACSHA512_NAME; if (dstkey != NULL && dst_key_alg(dstkey) != DST_ALG_HMACSHA512) { ret = DNS_R_BADALG; goto cleanup_name; } } else if (dns_name_equal(algorithm, DNS_TSIG_GSSAPI_NAME)) { tkey->algorithm = DNS_TSIG_GSSAPI_NAME; if (dstkey != NULL && dst_key_alg(dstkey) != DST_ALG_GSSAPI) { ret = DNS_R_BADALG; goto cleanup_name; } } else if (dns_name_equal(algorithm, DNS_TSIG_GSSAPIMS_NAME)) { tkey->algorithm = DNS_TSIG_GSSAPIMS_NAME; if (dstkey != NULL && dst_key_alg(dstkey) != DST_ALG_GSSAPI) { ret = DNS_R_BADALG; goto cleanup_name; } } else { if (dstkey != NULL) { ret = DNS_R_BADALG; goto cleanup_name; } tkey->algorithm = isc_mem_get(mctx, sizeof(dns_name_t)); if (tkey->algorithm == NULL) { ret = ISC_R_NOMEMORY; goto cleanup_name; } dns_name_init(tkey->algorithm, NULL); ret = dns_name_dup(algorithm, mctx, tkey->algorithm); if (ret != ISC_R_SUCCESS) goto cleanup_algorithm; (void)dns_name_downcase(tkey->algorithm, tkey->algorithm, NULL); } if (creator != NULL) { tkey->creator = isc_mem_get(mctx, sizeof(dns_name_t)); if (tkey->creator == NULL) { ret = ISC_R_NOMEMORY; goto cleanup_algorithm; } dns_name_init(tkey->creator, NULL); ret = dns_name_dup(creator, mctx, tkey->creator); if (ret != ISC_R_SUCCESS) { isc_mem_put(mctx, tkey->creator, sizeof(dns_name_t)); goto cleanup_algorithm; } } else tkey->creator = NULL; tkey->key = dstkey; tkey->ring = ring; if (key != NULL) refs++; if (ring != NULL) refs++; ret = isc_refcount_init(&tkey->refs, refs); if (ret != ISC_R_SUCCESS) goto cleanup_creator; tkey->generated = generated; tkey->inception = inception; tkey->expire = expire; tkey->mctx = mctx; tkey->magic = TSIG_MAGIC; if (ring != NULL) { RWLOCK(&ring->lock, isc_rwlocktype_write); ret = dns_rbt_addname(ring->keys, name, tkey); if (ret != ISC_R_SUCCESS) { RWUNLOCK(&ring->lock, isc_rwlocktype_write); goto cleanup_refs; } RWUNLOCK(&ring->lock, isc_rwlocktype_write); } if (dstkey != NULL && dst_key_size(dstkey) < 64) { char namestr[DNS_NAME_FORMATSIZE]; dns_name_format(name, namestr, sizeof(namestr)); isc_log_write(dns_lctx, DNS_LOGCATEGORY_DNSSEC, DNS_LOGMODULE_TSIG, ISC_LOG_INFO, "the key '%s' is too short to be secure", namestr); } if (key != NULL) *key = tkey; return (ISC_R_SUCCESS); cleanup_refs: tkey->magic = 0; while (refs-- > 0) isc_refcount_decrement(&tkey->refs, NULL); isc_refcount_destroy(&tkey->refs); cleanup_creator: if (tkey->creator != NULL) { dns_name_free(tkey->creator, mctx); isc_mem_put(mctx, tkey->creator, sizeof(dns_name_t)); } cleanup_algorithm: if (algname_is_allocated(tkey->algorithm)) { if (dns_name_dynamic(tkey->algorithm)) dns_name_free(tkey->algorithm, mctx); isc_mem_put(mctx, tkey->algorithm, sizeof(dns_name_t)); } cleanup_name: dns_name_free(&tkey->name, mctx); cleanup_key: isc_mem_put(mctx, tkey, sizeof(dns_tsigkey_t)); return (ret); } isc_result_t dns_tsigkey_create(dns_name_t *name, dns_name_t *algorithm, unsigned char *secret, int length, isc_boolean_t generated, dns_name_t *creator, isc_stdtime_t inception, isc_stdtime_t expire, isc_mem_t *mctx, dns_tsig_keyring_t *ring, dns_tsigkey_t **key) { dst_key_t *dstkey = NULL; isc_result_t result; REQUIRE(length >= 0); if (length > 0) REQUIRE(secret != NULL); if (dns_name_equal(algorithm, DNS_TSIG_HMACMD5_NAME)) { if (secret != NULL) { isc_buffer_t b; isc_buffer_init(&b, secret, length); isc_buffer_add(&b, length); result = dst_key_frombuffer(name, DST_ALG_HMACMD5, DNS_KEYOWNER_ENTITY, DNS_KEYPROTO_DNSSEC, dns_rdataclass_in, &b, mctx, &dstkey); if (result != ISC_R_SUCCESS) return (result); } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA1_NAME)) { if (secret != NULL) { isc_buffer_t b; isc_buffer_init(&b, secret, length); isc_buffer_add(&b, length); result = dst_key_frombuffer(name, DST_ALG_HMACSHA1, DNS_KEYOWNER_ENTITY, DNS_KEYPROTO_DNSSEC, dns_rdataclass_in, &b, mctx, &dstkey); if (result != ISC_R_SUCCESS) return (result); } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA224_NAME)) { if (secret != NULL) { isc_buffer_t b; isc_buffer_init(&b, secret, length); isc_buffer_add(&b, length); result = dst_key_frombuffer(name, DST_ALG_HMACSHA224, DNS_KEYOWNER_ENTITY, DNS_KEYPROTO_DNSSEC, dns_rdataclass_in, &b, mctx, &dstkey); if (result != ISC_R_SUCCESS) return (result); } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA256_NAME)) { if (secret != NULL) { isc_buffer_t b; isc_buffer_init(&b, secret, length); isc_buffer_add(&b, length); result = dst_key_frombuffer(name, DST_ALG_HMACSHA256, DNS_KEYOWNER_ENTITY, DNS_KEYPROTO_DNSSEC, dns_rdataclass_in, &b, mctx, &dstkey); if (result != ISC_R_SUCCESS) return (result); } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA384_NAME)) { if (secret != NULL) { isc_buffer_t b; isc_buffer_init(&b, secret, length); isc_buffer_add(&b, length); result = dst_key_frombuffer(name, DST_ALG_HMACSHA384, DNS_KEYOWNER_ENTITY, DNS_KEYPROTO_DNSSEC, dns_rdataclass_in, &b, mctx, &dstkey); if (result != ISC_R_SUCCESS) return (result); } } else if (dns_name_equal(algorithm, DNS_TSIG_HMACSHA512_NAME)) { if (secret != NULL) { isc_buffer_t b; isc_buffer_init(&b, secret, length); isc_buffer_add(&b, length); result = dst_key_frombuffer(name, DST_ALG_HMACSHA512, DNS_KEYOWNER_ENTITY, DNS_KEYPROTO_DNSSEC, dns_rdataclass_in, &b, mctx, &dstkey); if (result != ISC_R_SUCCESS) return (result); } } else if (length > 0) return (DNS_R_BADALG); result = dns_tsigkey_createfromkey(name, algorithm, dstkey, generated, creator, inception, expire, mctx, ring, key); if (result != ISC_R_SUCCESS && dstkey != NULL) dst_key_free(&dstkey); return (result); } void dns_tsigkey_attach(dns_tsigkey_t *source, dns_tsigkey_t **targetp) { REQUIRE(VALID_TSIG_KEY(source)); REQUIRE(targetp != NULL && *targetp == NULL); isc_refcount_increment(&source->refs, NULL); *targetp = source; } static void tsigkey_free(dns_tsigkey_t *key) { REQUIRE(VALID_TSIG_KEY(key)); key->magic = 0; dns_name_free(&key->name, key->mctx); if (algname_is_allocated(key->algorithm)) { dns_name_free(key->algorithm, key->mctx); isc_mem_put(key->mctx, key->algorithm, sizeof(dns_name_t)); } if (key->key != NULL) dst_key_free(&key->key); if (key->creator != NULL) { dns_name_free(key->creator, key->mctx); isc_mem_put(key->mctx, key->creator, sizeof(dns_name_t)); } isc_refcount_destroy(&key->refs); isc_mem_put(key->mctx, key, sizeof(dns_tsigkey_t)); } void dns_tsigkey_detach(dns_tsigkey_t **keyp) { dns_tsigkey_t *key; unsigned int refs; REQUIRE(keyp != NULL); REQUIRE(VALID_TSIG_KEY(*keyp)); key = *keyp; isc_refcount_decrement(&key->refs, &refs); if (refs == 0) tsigkey_free(key); *keyp = NULL; } void dns_tsigkey_setdeleted(dns_tsigkey_t *key) { REQUIRE(VALID_TSIG_KEY(key)); REQUIRE(key->ring != NULL); RWLOCK(&key->ring->lock, isc_rwlocktype_write); (void)dns_rbt_deletename(key->ring->keys, &key->name, ISC_FALSE); RWUNLOCK(&key->ring->lock, isc_rwlocktype_write); } static void buffer_putuint48(isc_buffer_t *b, isc_uint64_t val) { isc_uint16_t valhi; isc_uint32_t vallo; valhi = (isc_uint16_t)(val >> 32); vallo = (isc_uint32_t)(val & 0xFFFFFFFF); isc_buffer_putuint16(b, valhi); isc_buffer_putuint32(b, vallo); } 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; REQUIRE(msg != NULL); REQUIRE(VALID_TSIG_KEY(dns_message_gettsigkey(msg))); /* * If this is a response, there should be a query tsig. */ if (is_response(msg) && 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 (is_response(msg)) 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); 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_create(key->key, mctx, &ctx); if (ret != ISC_R_SUCCESS) return (ret); /* * If this is a response, digest the query signature. */ if (is_response(msg)) { 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; } /* * 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) tsig.timesigned = querytsig.timesigned; 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 the error and 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 (is_response(msg) && 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); dns_rdataset_init(dataset); RUNTIME_CHECK(dns_rdatalist_tordataset(datalist, dataset) == ISC_R_SUCCESS); msg->tsig = dataset; msg->tsigname = owner; 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; REQUIRE(source != NULL); REQUIRE(DNS_MESSAGE_VALID(msg)); tsigkey = dns_message_gettsigkey(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 (is_response(msg) && (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 (is_response(msg)) { 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); } /* * Do the key name and algorithm match that of the query? */ if (is_response(msg) && (!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 to 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_create(key, mctx, &ctx); if (ret != ISC_R_SUCCESS) return (ret); if (is_response(msg)) { 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); memcpy(header, r.base, DNS_MESSAGE_HEADERLEN); isc_region_consume(&r, DNS_MESSAGE_HEADERLEN); /* * Decrement the additional field counter. */ memcpy(&addcount, &header[DNS_MESSAGE_HEADERLEN - 2], 2); addcount = htons((isc_uint16_t)(ntohs(addcount) - 1)); memcpy(&header[DNS_MESSAGE_HEADERLEN - 2], &addcount, 2); /* * Put in the original id. */ id = htons(tsig.originalid); memcpy(&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); 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"); 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_create(key, mctx, &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); memcpy(header, r.base, DNS_MESSAGE_HEADERLEN); isc_region_consume(&r, DNS_MESSAGE_HEADERLEN); /* * Decrement the additional field counter if necessary. */ if (has_tsig) { memcpy(&addcount, &header[DNS_MESSAGE_HEADERLEN - 2], 2); addcount = htons((isc_uint16_t)(ntohs(addcount) - 1)); memcpy(&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); memcpy(&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)); 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"); 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); } isc_result_t dns_tsigkey_find(dns_tsigkey_t **tsigkey, dns_name_t *name, dns_name_t *algorithm, dns_tsig_keyring_t *ring) { dns_tsigkey_t *key; isc_stdtime_t now; isc_result_t result; REQUIRE(tsigkey != NULL); REQUIRE(*tsigkey == NULL); REQUIRE(name != NULL); REQUIRE(ring != NULL); isc_stdtime_get(&now); RWLOCK(&ring->lock, isc_rwlocktype_read); key = NULL; result = dns_rbt_findname(ring->keys, name, 0, NULL, (void *)&key); if (result == DNS_R_PARTIALMATCH || result == ISC_R_NOTFOUND) { RWUNLOCK(&ring->lock, isc_rwlocktype_read); return (ISC_R_NOTFOUND); } if (algorithm != NULL && !dns_name_equal(key->algorithm, algorithm)) { RWUNLOCK(&ring->lock, isc_rwlocktype_read); return (ISC_R_NOTFOUND); } if (key->inception != key->expire && key->expire < now) { /* * The key has expired. */ RWUNLOCK(&ring->lock, isc_rwlocktype_read); RWLOCK(&ring->lock, isc_rwlocktype_write); (void) dns_rbt_deletename(ring->keys, name, ISC_FALSE); RWUNLOCK(&ring->lock, isc_rwlocktype_write); return (ISC_R_NOTFOUND); } isc_refcount_increment(&key->refs, NULL); RWUNLOCK(&ring->lock, isc_rwlocktype_read); *tsigkey = key; return (ISC_R_SUCCESS); } static void free_tsignode(void *node, void *_unused) { dns_tsigkey_t *key; UNUSED(_unused); REQUIRE(node != NULL); key = node; dns_tsigkey_detach(&key); } isc_result_t dns_tsigkeyring_create(isc_mem_t *mctx, dns_tsig_keyring_t **ringp) { isc_result_t result; dns_tsig_keyring_t *ring; REQUIRE(mctx != NULL); REQUIRE(ringp != NULL); REQUIRE(*ringp == NULL); ring = isc_mem_get(mctx, sizeof(dns_tsig_keyring_t)); if (ring == NULL) return (ISC_R_NOMEMORY); result = isc_rwlock_init(&ring->lock, 0, 0); if (result != ISC_R_SUCCESS) { isc_mem_put(mctx, ring, sizeof(dns_tsig_keyring_t)); return (result); } ring->keys = NULL; result = dns_rbt_create(mctx, free_tsignode, NULL, &ring->keys); if (result != ISC_R_SUCCESS) { isc_rwlock_destroy(&ring->lock); isc_mem_put(mctx, ring, sizeof(dns_tsig_keyring_t)); return (result); } ring->mctx = mctx; *ringp = ring; return (ISC_R_SUCCESS); } void dns_tsigkeyring_destroy(dns_tsig_keyring_t **ringp) { dns_tsig_keyring_t *ring; REQUIRE(ringp != NULL); REQUIRE(*ringp != NULL); ring = *ringp; *ringp = NULL; dns_rbt_destroy(&ring->keys); isc_rwlock_destroy(&ring->lock); isc_mem_put(ring->mctx, ring, sizeof(dns_tsig_keyring_t)); }