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/*
* This file is part of PowerDNS or dnsdist.
* Copyright -- PowerDNS.COM B.V. and its contributors
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* In addition, for the avoidance of any doubt, permission is granted to
* link this program with OpenSSL and to (re)distribute the binaries
* produced as the result of such linking.
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "base64.hh"
#include "dnsdist-doh-common.hh"
#include "dnsdist-rules.hh"
#ifdef HAVE_DNS_OVER_HTTPS
HTTPHeaderRule::HTTPHeaderRule(const std::string& header, const std::string& regex) :
d_header(toLower(header)), d_regex(regex), d_visual("http[" + header + "] ~ " + regex)
{
}
bool HTTPHeaderRule::matches(const DNSQuestion* dq) const
{
if (!dq->ids.du) {
return false;
}
const auto& headers = dq->ids.du->getHTTPHeaders();
for (const auto& header : headers) {
if (header.first == d_header) {
return d_regex.match(header.second);
}
}
return false;
}
string HTTPHeaderRule::toString() const
{
return d_visual;
}
HTTPPathRule::HTTPPathRule(std::string path) :
d_path(std::move(path))
{
}
bool HTTPPathRule::matches(const DNSQuestion* dq) const
{
if (!dq->ids.du) {
return false;
}
const auto path = dq->ids.du->getHTTPPath();
return d_path == path;
}
string HTTPPathRule::toString() const
{
return "url path == " + d_path;
}
HTTPPathRegexRule::HTTPPathRegexRule(const std::string& regex) :
d_regex(regex), d_visual("http path ~ " + regex)
{
}
bool HTTPPathRegexRule::matches(const DNSQuestion* dq) const
{
if (!dq->ids.du) {
return false;
}
return d_regex.match(dq->ids.du->getHTTPPath());
}
string HTTPPathRegexRule::toString() const
{
return d_visual;
}
void DOHFrontend::rotateTicketsKey(time_t now)
{
return d_tlsContext.rotateTicketsKey(now);
}
void DOHFrontend::loadTicketsKeys(const std::string& keyFile)
{
return d_tlsContext.loadTicketsKeys(keyFile);
}
void DOHFrontend::handleTicketsKeyRotation()
{
}
std::string DOHFrontend::getNextTicketsKeyRotation() const
{
return d_tlsContext.getNextTicketsKeyRotation();
}
size_t DOHFrontend::getTicketsKeysCount()
{
return d_tlsContext.getTicketsKeysCount();
}
void DOHFrontend::reloadCertificates()
{
d_tlsContext.setupTLS();
}
void DOHFrontend::setup()
{
if (isHTTPS()) {
if (!d_tlsContext.setupTLS()) {
throw std::runtime_error("Error setting up TLS context for DoH listener on '" + d_tlsContext.d_addr.toStringWithPort());
}
}
}
#endif /* HAVE_DNS_OVER_HTTPS */
namespace dnsdist::doh
{
std::optional<PacketBuffer> getPayloadFromPath(const std::string_view& path)
{
std::optional<PacketBuffer> result{std::nullopt};
if (path.size() <= 5) {
return result;
}
auto pos = path.find("?dns=");
if (pos == string::npos) {
pos = path.find("&dns=");
}
if (pos == string::npos) {
return result;
}
// need to base64url decode this
string sdns;
const size_t payloadSize = path.size() - pos - 5;
size_t neededPadding = 0;
switch (payloadSize % 4) {
case 2:
neededPadding = 2;
break;
case 3:
neededPadding = 1;
break;
}
sdns.reserve(payloadSize + neededPadding);
sdns = path.substr(pos + 5);
for (auto& entry : sdns) {
switch (entry) {
case '-':
entry = '+';
break;
case '_':
entry = '/';
break;
}
}
if (neededPadding != 0) {
// re-add padding that may have been missing
sdns.append(neededPadding, '=');
}
PacketBuffer decoded;
/* rough estimate so we hopefully don't need a new allocation later */
/* We reserve at few additional bytes to be able to add EDNS later */
const size_t estimate = ((sdns.size() * 3) / 4);
decoded.reserve(estimate);
if (B64Decode(sdns, decoded) < 0) {
return result;
}
result = std::move(decoded);
return result;
}
}
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