📄 tsig.c
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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; 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); tsig.siglen = isc_buffer_usedlength(&sigbuf); } else { tsig.siglen = 0; tsig.signature = NULL; } rdata = 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_signature; 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_dynbuf; 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; 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); dataset = NULL; ret = dns_message_gettemprdataset(msg, &dataset); if (ret != ISC_R_SUCCESS) goto cleanup_owner; 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_owner: if (owner != NULL) dns_message_puttempname(msg, &owner);cleanup_dynbuf: if (dynbuf != NULL) isc_buffer_free(&dynbuf);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_tdns_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; 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) 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); } 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.
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