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Commit df84656e authored by Karel Slaný's avatar Karel Slaný
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layer/validate: signature checking moved to separate compilation unit

parent 0db970d8
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lib/dnssec.c
+ 3
− 202
View file @ df84656e
......@@ -21,7 +21,6 @@
#include <dnssec/key.h>
#include <dnssec/sign.h>
#include <libknot/descriptor.h>
#include <libknot/packet/rrset-wire.h>
#include <libknot/packet/wire.h>
#include <libknot/rdataset.h>
#include <libknot/rrset.h>
......@@ -31,7 +30,7 @@
#include "lib/defines.h"
#include "lib/dnssec/rrtype/ds.h"
#include "lib/dnssec/signature.h"
#include "lib/dnssec.h"
#define DEBUG_MSG(fmt...) fprintf(stderr, fmt)
......@@ -51,41 +50,6 @@ void kr_crypto_reinit(void)
dnssec_crypto_reinit();
}
/* RFC4035 5.2, bullet 2 */
static int authenticate_referral(const dnssec_key_t *key, const knot_rrset_t *ds)
{
assert(key && ds);
assert(ds->type == KNOT_RRTYPE_DS);
int ret = 0;
dnssec_binary_t orig_ds_rdata;
dnssec_binary_t generated_ds_rdata = {0, };
{
/* Obtain RDATA of the supplied DS. */
const knot_rdata_t *rr = knot_rdataset_at(&ds->rrs, 0);
orig_ds_rdata.size = knot_rdata_rdlen(rr);
orig_ds_rdata.data = knot_rdata_data(rr);
}
/* Compute DS RDATA from the DNSKEY. */
ret = dnssec_key_create_ds(key, _knot_ds_dtype(&ds->rrs, 0), &generated_ds_rdata);
if (ret != DNSSEC_EOK) {
ret = kr_error(ENOMEM);
goto fail;
}
/* DS records contain algorithm, key tag and the digest.
* Therefore the comparison of the two DS is sufficient.
*/
ret = ((orig_ds_rdata.size == generated_ds_rdata.size) &&
(memcmp(orig_ds_rdata.data, generated_ds_rdata.data, orig_ds_rdata.size) == 0)) ? kr_ok() : kr_error(KNOT_DNSSEC_ENOKEY);
fail:
dnssec_binary_free(&generated_ds_rdata);
return ret;
}
#define FLG_WILDCARD_EXPANSION 0x01 /**< Possibly generated by using wildcard expansion. */
/**
......@@ -155,169 +119,6 @@ static int validate_rrsig_rr(int *flags, const knot_rrset_t *covered,
return kr_ok();
}
/*!
* \brief Add RRSIG RDATA without signature to signing context.
*
* Requires signer name in RDATA in canonical form.
*
* \param ctx Signing context.
* \param rdata Pointer to RRSIG RDATA.
*
* \return Error code, KNOT_EOK if successful.
*/
#define RRSIG_RDATA_SIGNER_OFFSET 18
static int sign_ctx_add_self(dnssec_sign_ctx_t *ctx, const uint8_t *rdata)
{
assert(ctx);
assert(rdata);
int result;
// static header
dnssec_binary_t header = { 0 };
header.data = (uint8_t *)rdata;
header.size = RRSIG_RDATA_SIGNER_OFFSET;
result = dnssec_sign_add(ctx, &header);
if (result != DNSSEC_EOK) {
return result;
}
// signer name
const uint8_t *rdata_signer = rdata + RRSIG_RDATA_SIGNER_OFFSET;
dnssec_binary_t signer = { 0 };
signer.data = knot_dname_copy(rdata_signer, NULL);
signer.size = knot_dname_size(signer.data);
result = dnssec_sign_add(ctx, &signer);
free(signer.data);
return result;
}
#undef RRSIG_RDATA_SIGNER_OFFSET
/*!
* \brief Add covered RRs to signing context.
*
* Requires all DNAMEs in canonical form and all RRs ordered canonically.
*
* \param ctx Signing context.
* \param covered Covered RRs.
*
* \return Error code, KNOT_EOK if successful.
*/
static int sign_ctx_add_records(dnssec_sign_ctx_t *ctx, const knot_rrset_t *covered,
int trim_labels)
{
// huge block of rrsets can be optionally created
uint8_t *rrwf = malloc(KNOT_WIRE_MAX_PKTSIZE);
if (!rrwf) {
return KNOT_ENOMEM;
}
int written = knot_rrset_to_wire(covered, rrwf, KNOT_WIRE_MAX_PKTSIZE, NULL);
if (written < 0) {
free(rrwf);
return written;
}
/* RFC4035 5.3.2
* Remove leftmost labels and replace them with '*.'.
*/
uint8_t *owner = rrwf;
if (trim_labels > 0) {
/**/
for (int i = 0; i < trim_labels; ++i) {
owner = (uint8_t *) knot_wire_next_label(owner, NULL);
}
*(--owner) = '*';
*(--owner) = 1;
}
dnssec_binary_t rrset_wire = { 0 };
rrset_wire.size = written - (owner - rrwf);
rrset_wire.data = owner;
int result = dnssec_sign_add(ctx, &rrset_wire);
free(rrwf);
return result;
}
/*!
* \brief Add all data covered by signature into signing context.
*
* RFC 4034: The signature covers RRSIG RDATA field (excluding the signature)
* and all matching RR records, which are ordered canonically.
*
* Requires all DNAMEs in canonical form and all RRs ordered canonically.
*
* \param ctx Signing context.
* \param rrsig_rdata RRSIG RDATA with populated fields except signature.
* \param covered Covered RRs.
*
* \return Error code, KNOT_EOK if successful.
*/
/* TODO -- Taken from knot/src/knot/dnssec/rrset-sign.c. Re-write for better fit needed. */
static int sign_ctx_add_data(dnssec_sign_ctx_t *ctx, const uint8_t *rrsig_rdata,
const knot_rrset_t *covered, int trim_labels)
{
int result = sign_ctx_add_self(ctx, rrsig_rdata);
if (result != KNOT_EOK) {
return result;
}
return sign_ctx_add_records(ctx, covered, trim_labels);
}
/* RFC4035 5.3.3 and 5.3.2 */
static int check_signature(const knot_rrset_t *rrsigs, size_t pos, const dnssec_key_t *key,
const knot_rrset_t *covered, int trim_labels)
{
if (!rrsigs || !key || !dnssec_key_can_verify(key)) {
return kr_error(EINVAL);
}
int ret;
dnssec_sign_ctx_t *sign_ctx = NULL;
dnssec_binary_t signature = {0, };
knot_rrsig_signature(&rrsigs->rrs, pos, &signature.data, &signature.size);
if (!signature.data || !signature.size) {
ret = kr_error(EINVAL);
goto fail;
}
ret = dnssec_sign_new(&sign_ctx, key);
if (ret != DNSSEC_EOK) {
ret = kr_error(ENOMEM);
goto fail;
}
const knot_rdata_t *rr_data = knot_rdataset_at(&rrsigs->rrs, pos);
uint8_t *rdata = knot_rdata_data(rr_data);
ret = sign_ctx_add_data(sign_ctx, rdata, covered, trim_labels);
if (ret != KNOT_EOK) {
ret = kr_error(ENOMEM);
goto fail;
}
ret = dnssec_sign_verify(sign_ctx, &signature);
if (ret != KNOT_EOK) {
#warning TODO: proper DNSSEC error codes needed
ret = kr_error(ENOMEM);
goto fail;
}
ret = kr_ok();
fail:
dnssec_sign_free(sign_ctx);
return ret;
}
/**
* Returns the number of labels that have been added by wildcard expansion.
* @param expanded Expanded wildcard.
......@@ -448,7 +249,7 @@ int kr_rrset_validate_with_key(const knot_pkt_t *pkt, knot_section_t section_id,
break;
}
}
if (check_signature(rrsig, j, (dnssec_key_t *) key, covered, trim_labels) != 0) {
if (kr_check_signature(rrsig, j, (dnssec_key_t *) key, covered, trim_labels) != 0) {
continue;
}
if (val_flgs & FLG_WILDCARD_EXPANSION) {
......@@ -494,7 +295,7 @@ int kr_dnskeys_trusted(const knot_pkt_t *pkt, knot_section_t section_id, const k
if (kr_dnssec_key_from_rdata(&key, krr, keys->owner) != 0) {
continue;
}
if (authenticate_referral((dnssec_key_t *) key, ta) != 0) {
if (kr_authenticate_referral(ta, (dnssec_key_t *) key) != 0) {
kr_dnssec_key_free(&key);
continue;
}
......
lib/dnssec/signature.c 0 → 100644
+ 232
− 0
View file @ df84656e
/* Copyright (C) 2015 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <string.h>
#include <dnssec/error.h>
#include <dnssec/key.h>
#include <dnssec/sign.h>
#include <libknot/descriptor.h>
#include <libknot/packet/rrset-wire.h>
#include <libknot/packet/wire.h>
#include <libknot/rrset.h>
#include <libknot/rrtype/rrsig.h>
#include "lib/defines.h"
#include "lib/dnssec/rrtype/ds.h"
#include "lib/dnssec/signature.h"
int kr_authenticate_referral(const knot_rrset_t *ref, const dnssec_key_t *key)
{
assert(ref && key);
if (ref->type != KNOT_RRTYPE_DS) {
assert(0);
return kr_error(EINVAL);
}
int ret = 0;
dnssec_binary_t orig_ds_rdata;
dnssec_binary_t generated_ds_rdata = {0, };
{
/* Obtain RDATA of the supplied DS. */
const knot_rdata_t *rr = knot_rdataset_at(&ref->rrs, 0);
orig_ds_rdata.size = knot_rdata_rdlen(rr);
orig_ds_rdata.data = knot_rdata_data(rr);
}
/* Compute DS RDATA from the DNSKEY. */
ret = dnssec_key_create_ds(key, _knot_ds_dtype(&ref->rrs, 0), &generated_ds_rdata);
if (ret != DNSSEC_EOK) {
ret = kr_error(ENOMEM);
goto fail;
}
/* DS records contain algorithm, key tag and the digest.
* Therefore the comparison of the two DS is sufficient.
*/
ret = (orig_ds_rdata.size == generated_ds_rdata.size) &&
(memcmp(orig_ds_rdata.data, generated_ds_rdata.data, orig_ds_rdata.size) == 0);
ret = ret ? kr_ok() : kr_error(KNOT_DNSSEC_ENOKEY);
fail:
dnssec_binary_free(&generated_ds_rdata);
return ret;
}
/*!
* \brief Add RRSIG RDATA without signature to signing context.
*
* Requires signer name in RDATA in canonical form.
*
* \param ctx Signing context.
* \param rdata Pointer to RRSIG RDATA.
*
* \return Error code, KNOT_EOK if successful.
*/
#define RRSIG_RDATA_SIGNER_OFFSET 18
static int sign_ctx_add_self(dnssec_sign_ctx_t *ctx, const uint8_t *rdata)
{
assert(ctx);
assert(rdata);
int result;
// static header
dnssec_binary_t header = { 0 };
header.data = (uint8_t *)rdata;
header.size = RRSIG_RDATA_SIGNER_OFFSET;
result = dnssec_sign_add(ctx, &header);
if (result != DNSSEC_EOK) {
return result;
}
// signer name
const uint8_t *rdata_signer = rdata + RRSIG_RDATA_SIGNER_OFFSET;
dnssec_binary_t signer = { 0 };
signer.data = knot_dname_copy(rdata_signer, NULL);
signer.size = knot_dname_size(signer.data);
result = dnssec_sign_add(ctx, &signer);
free(signer.data);
return result;
}
#undef RRSIG_RDATA_SIGNER_OFFSET
/*!
* \brief Add covered RRs to signing context.
*
* Requires all DNAMEs in canonical form and all RRs ordered canonically.
*
* \param ctx Signing context.
* \param covered Covered RRs.
*
* \return Error code, KNOT_EOK if successful.
*/
static int sign_ctx_add_records(dnssec_sign_ctx_t *ctx, const knot_rrset_t *covered,
int trim_labels)
{
// huge block of rrsets can be optionally created
uint8_t *rrwf = malloc(KNOT_WIRE_MAX_PKTSIZE);
if (!rrwf) {
return KNOT_ENOMEM;
}
int written = knot_rrset_to_wire(covered, rrwf, KNOT_WIRE_MAX_PKTSIZE, NULL);
if (written < 0) {
free(rrwf);
return written;
}
/* RFC4035 5.3.2
* Remove leftmost labels and replace them with '*.'.
*/
uint8_t *owner = rrwf;
if (trim_labels > 0) {
/**/
for (int i = 0; i < trim_labels; ++i) {
owner = (uint8_t *) knot_wire_next_label(owner, NULL);
}
*(--owner) = '*';
*(--owner) = 1;
}
dnssec_binary_t rrset_wire = { 0 };
rrset_wire.size = written - (owner - rrwf);
rrset_wire.data = owner;
int result = dnssec_sign_add(ctx, &rrset_wire);
free(rrwf);
return result;
}
/*!
* \brief Add all data covered by signature into signing context.
*
* RFC 4034: The signature covers RRSIG RDATA field (excluding the signature)
* and all matching RR records, which are ordered canonically.
*
* Requires all DNAMEs in canonical form and all RRs ordered canonically.
*
* \param ctx Signing context.
* \param rrsig_rdata RRSIG RDATA with populated fields except signature.
* \param covered Covered RRs.
*
* \return Error code, KNOT_EOK if successful.
*/
/* TODO -- Taken from knot/src/knot/dnssec/rrset-sign.c. Re-write for better fit needed. */
static int sign_ctx_add_data(dnssec_sign_ctx_t *ctx, const uint8_t *rrsig_rdata,
const knot_rrset_t *covered, int trim_labels)
{
int result = sign_ctx_add_self(ctx, rrsig_rdata);
if (result != KNOT_EOK) {
return result;
}
return sign_ctx_add_records(ctx, covered, trim_labels);
}
int kr_check_signature(const knot_rrset_t *rrsigs, size_t pos,
const dnssec_key_t *key, const knot_rrset_t *covered,
int trim_labels)
{
if (!rrsigs || !key || !dnssec_key_can_verify(key)) {
return kr_error(EINVAL);
}
int ret;
dnssec_sign_ctx_t *sign_ctx = NULL;
dnssec_binary_t signature = {0, };
knot_rrsig_signature(&rrsigs->rrs, pos, &signature.data, &signature.size);
if (!signature.data || !signature.size) {
ret = kr_error(EINVAL);
goto fail;
}
ret = dnssec_sign_new(&sign_ctx, key);
if (ret != DNSSEC_EOK) {
ret = kr_error(ENOMEM);
goto fail;
}
const knot_rdata_t *rr_data = knot_rdataset_at(&rrsigs->rrs, pos);
uint8_t *rdata = knot_rdata_data(rr_data);
ret = sign_ctx_add_data(sign_ctx, rdata, covered, trim_labels);
if (ret != KNOT_EOK) {
ret = kr_error(ENOMEM);
goto fail;
}
ret = dnssec_sign_verify(sign_ctx, &signature);
if (ret != KNOT_EOK) {
#warning TODO: proper DNSSEC error codes needed
ret = kr_error(ENOMEM);
goto fail;
}
ret = kr_ok();
fail:
dnssec_sign_free(sign_ctx);
return ret;
}
lib/dnssec/signature.h 0 → 100644
+ 41
− 0
View file @ df84656e
/* Copyright (C) 2015 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <dnssec/key.h>
#include <libknot/rrset.h>
/**
* Performs referral authentication according to RFC4035 5.2, bullet 2
* @param ref Referral RRSet. Currently only DS can be used.
* @param key Already parsed key.
* @return 0 or error code.
*/
int kr_authenticate_referral(const knot_rrset_t *ref, const dnssec_key_t *key);
/**
* Check the signature of the supplied RRSet.
* @param rrsigs RRSet containing signatures.
* @param pos Index of the signature record in the signature RRSet.
* @param key Key to be used to validate the signature.
* @param covered The covered RRSet.
* @param trim_labels Number of the leftmost labels to be removed and replaced with '*.'.
* @return 0 if signature valid, error code else.
*/
int kr_check_signature(const knot_rrset_t *rrsigs, size_t pos,
const dnssec_key_t *key, const knot_rrset_t *covered,
int trim_labels);
lib/lib.mk
+ 2
− 0
View file @ df84656e
......@@ -11,6 +11,7 @@ libkres_SOURCES := \
lib/layer/validate.c \
lib/layer/rrcache.c \
lib/layer/pktcache.c \
lib/dnssec/signature.c \
lib/dnssec/ta.c \
lib/dnssec.c \
lib/utils.c \
......@@ -27,6 +28,7 @@ libkres_HEADERS := \
lib/generic/set.h \
lib/layer.h \
lib/kayer/rrset/ds.h \
lib/dnssec/signature.h \
lib/dnssec/ta.h \
lib/dnssec.h \
lib/utils.h \
......
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