nghttp2/src/shrpx_quic.cc

373 lines
11 KiB
C++

/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2021 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "shrpx_quic.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/udp.h>
#include <array>
#include <chrono>
#include <ngtcp2/ngtcp2_crypto.h>
#include <nghttp3/nghttp3.h>
#include <openssl/rand.h>
#include "shrpx_config.h"
#include "shrpx_log.h"
#include "util.h"
#include "xsi_strerror.h"
bool operator==(const ngtcp2_cid &lhs, const ngtcp2_cid &rhs) {
return ngtcp2_cid_eq(&lhs, &rhs);
}
namespace shrpx {
ngtcp2_tstamp quic_timestamp() {
return std::chrono::duration_cast<std::chrono::nanoseconds>(
std::chrono::steady_clock::now().time_since_epoch())
.count();
}
int quic_send_packet(const UpstreamAddr *faddr, const sockaddr *remote_sa,
size_t remote_salen, const sockaddr *local_sa,
size_t local_salen, const ngtcp2_pkt_info &pi,
const uint8_t *data, size_t datalen, size_t gso_size) {
iovec msg_iov = {const_cast<uint8_t *>(data), datalen};
msghdr msg{};
msg.msg_name = const_cast<sockaddr *>(remote_sa);
msg.msg_namelen = remote_salen;
msg.msg_iov = &msg_iov;
msg.msg_iovlen = 1;
uint8_t msg_ctrl[
#ifdef UDP_SEGMENT
CMSG_SPACE(sizeof(uint16_t)) +
#endif // UDP_SEGMENT
CMSG_SPACE(sizeof(in6_pktinfo))];
memset(msg_ctrl, 0, sizeof(msg_ctrl));
msg.msg_control = msg_ctrl;
msg.msg_controllen = sizeof(msg_ctrl);
size_t controllen = 0;
auto cm = CMSG_FIRSTHDR(&msg);
switch (local_sa->sa_family) {
case AF_INET: {
controllen += CMSG_SPACE(sizeof(in_pktinfo));
cm->cmsg_level = IPPROTO_IP;
cm->cmsg_type = IP_PKTINFO;
cm->cmsg_len = CMSG_LEN(sizeof(in_pktinfo));
auto pktinfo = reinterpret_cast<in_pktinfo *>(CMSG_DATA(cm));
memset(pktinfo, 0, sizeof(in_pktinfo));
auto addrin =
reinterpret_cast<sockaddr_in *>(const_cast<sockaddr *>(local_sa));
pktinfo->ipi_spec_dst = addrin->sin_addr;
break;
}
case AF_INET6: {
controllen += CMSG_SPACE(sizeof(in6_pktinfo));
cm->cmsg_level = IPPROTO_IPV6;
cm->cmsg_type = IPV6_PKTINFO;
cm->cmsg_len = CMSG_LEN(sizeof(in6_pktinfo));
auto pktinfo = reinterpret_cast<in6_pktinfo *>(CMSG_DATA(cm));
memset(pktinfo, 0, sizeof(in6_pktinfo));
auto addrin =
reinterpret_cast<sockaddr_in6 *>(const_cast<sockaddr *>(local_sa));
pktinfo->ipi6_addr = addrin->sin6_addr;
break;
}
default:
assert(0);
}
#ifdef UDP_SEGMENT
if (gso_size && datalen > gso_size) {
controllen += CMSG_SPACE(sizeof(uint16_t));
cm = CMSG_NXTHDR(&msg, cm);
cm->cmsg_level = SOL_UDP;
cm->cmsg_type = UDP_SEGMENT;
cm->cmsg_len = CMSG_LEN(sizeof(uint16_t));
*(reinterpret_cast<uint16_t *>(CMSG_DATA(cm))) = gso_size;
}
#endif // UDP_SEGMENT
msg.msg_controllen = controllen;
util::fd_set_send_ecn(faddr->fd, local_sa->sa_family, pi.ecn);
ssize_t nwrite;
do {
nwrite = sendmsg(faddr->fd, &msg, 0);
} while (nwrite == -1 && errno == EINTR);
if (nwrite == -1) {
if (LOG_ENABLED(INFO)) {
auto error = errno;
LOG(INFO) << "sendmsg failed: errno=" << error;
}
return -errno;
}
if (LOG_ENABLED(INFO)) {
LOG(INFO) << "QUIC sent packet: local="
<< util::to_numeric_addr(local_sa, local_salen)
<< " remote=" << util::to_numeric_addr(remote_sa, remote_salen)
<< " ecn=" << log::hex << pi.ecn << log::dec << " " << nwrite
<< " bytes";
}
return 0;
}
int generate_quic_retry_connection_id(ngtcp2_cid &cid, size_t cidlen,
const uint8_t *server_id, uint8_t km_id,
const uint8_t *key) {
assert(cidlen == SHRPX_QUIC_SCIDLEN);
if (RAND_bytes(cid.data, cidlen) != 1) {
return -1;
}
cid.datalen = cidlen;
cid.data[0] = (cid.data[0] & 0x3f) | km_id;
auto p = cid.data + SHRPX_QUIC_CID_PREFIX_OFFSET;
std::copy_n(server_id, SHRPX_QUIC_SERVER_IDLEN, p);
return encrypt_quic_connection_id(p, p, key);
}
int generate_quic_connection_id(ngtcp2_cid &cid, size_t cidlen,
const uint8_t *cid_prefix, uint8_t km_id,
const uint8_t *key) {
assert(cidlen == SHRPX_QUIC_SCIDLEN);
if (RAND_bytes(cid.data, cidlen) != 1) {
return -1;
}
cid.datalen = cidlen;
cid.data[0] = (cid.data[0] & 0x3f) | km_id;
auto p = cid.data + SHRPX_QUIC_CID_PREFIX_OFFSET;
std::copy_n(cid_prefix, SHRPX_QUIC_CID_PREFIXLEN, p);
return encrypt_quic_connection_id(p, p, key);
}
int encrypt_quic_connection_id(uint8_t *dest, const uint8_t *src,
const uint8_t *key) {
auto ctx = EVP_CIPHER_CTX_new();
auto d = defer(EVP_CIPHER_CTX_free, ctx);
if (!EVP_EncryptInit_ex(ctx, EVP_aes_128_ecb(), nullptr, key, nullptr)) {
return -1;
}
EVP_CIPHER_CTX_set_padding(ctx, 0);
int len;
if (!EVP_EncryptUpdate(ctx, dest, &len, src, SHRPX_QUIC_DECRYPTED_DCIDLEN) ||
!EVP_EncryptFinal_ex(ctx, dest + len, &len)) {
return -1;
}
return 0;
}
int decrypt_quic_connection_id(uint8_t *dest, const uint8_t *src,
const uint8_t *key) {
auto ctx = EVP_CIPHER_CTX_new();
auto d = defer(EVP_CIPHER_CTX_free, ctx);
if (!EVP_DecryptInit_ex(ctx, EVP_aes_128_ecb(), nullptr, key, nullptr)) {
return -1;
}
EVP_CIPHER_CTX_set_padding(ctx, 0);
int len;
if (!EVP_DecryptUpdate(ctx, dest, &len, src, SHRPX_QUIC_DECRYPTED_DCIDLEN) ||
!EVP_DecryptFinal_ex(ctx, dest + len, &len)) {
return -1;
}
return 0;
}
int generate_quic_hashed_connection_id(ngtcp2_cid &dest,
const Address &remote_addr,
const Address &local_addr,
const ngtcp2_cid &cid) {
auto ctx = EVP_MD_CTX_new();
auto d = defer(EVP_MD_CTX_free, ctx);
std::array<uint8_t, 32> h;
unsigned int hlen = EVP_MD_size(EVP_sha256());
if (!EVP_DigestInit_ex(ctx, EVP_sha256(), nullptr) ||
!EVP_DigestUpdate(ctx, &remote_addr.su.sa, remote_addr.len) ||
!EVP_DigestUpdate(ctx, &local_addr.su.sa, local_addr.len) ||
!EVP_DigestUpdate(ctx, cid.data, cid.datalen) ||
!EVP_DigestFinal_ex(ctx, h.data(), &hlen)) {
return -1;
}
assert(hlen == h.size());
std::copy_n(std::begin(h), sizeof(dest.data), std::begin(dest.data));
dest.datalen = sizeof(dest.data);
return 0;
}
int generate_quic_stateless_reset_token(uint8_t *token, const ngtcp2_cid &cid,
const uint8_t *secret,
size_t secretlen) {
if (ngtcp2_crypto_generate_stateless_reset_token(token, secret, secretlen,
&cid) != 0) {
return -1;
}
return 0;
}
int generate_retry_token(uint8_t *token, size_t &tokenlen, const sockaddr *sa,
socklen_t salen, const ngtcp2_cid &retry_scid,
const ngtcp2_cid &odcid, const uint8_t *secret,
size_t secretlen) {
auto t = std::chrono::duration_cast<std::chrono::nanoseconds>(
std::chrono::system_clock::now().time_since_epoch())
.count();
auto stokenlen = ngtcp2_crypto_generate_retry_token(
token, secret, secretlen, sa, salen, &retry_scid, &odcid, t);
if (stokenlen < 0) {
return -1;
}
tokenlen = stokenlen;
return 0;
}
int verify_retry_token(ngtcp2_cid &odcid, const uint8_t *token, size_t tokenlen,
const ngtcp2_cid &dcid, const sockaddr *sa,
socklen_t salen, const uint8_t *secret,
size_t secretlen) {
auto t = std::chrono::duration_cast<std::chrono::nanoseconds>(
std::chrono::system_clock::now().time_since_epoch())
.count();
if (ngtcp2_crypto_verify_retry_token(&odcid, token, tokenlen, secret,
secretlen, sa, salen, &dcid,
10 * NGTCP2_SECONDS, t) != 0) {
return -1;
}
return 0;
}
int generate_token(uint8_t *token, size_t &tokenlen, const sockaddr *sa,
size_t salen, const uint8_t *secret, size_t secretlen) {
auto t = std::chrono::duration_cast<std::chrono::nanoseconds>(
std::chrono::system_clock::now().time_since_epoch())
.count();
auto stokenlen = ngtcp2_crypto_generate_regular_token(
token, secret, secretlen, sa, salen, t);
if (stokenlen < 0) {
return -1;
}
tokenlen = stokenlen;
return 0;
}
int verify_token(const uint8_t *token, size_t tokenlen, const sockaddr *sa,
socklen_t salen, const uint8_t *secret, size_t secretlen) {
auto t = std::chrono::duration_cast<std::chrono::nanoseconds>(
std::chrono::system_clock::now().time_since_epoch())
.count();
if (ngtcp2_crypto_verify_regular_token(token, tokenlen, secret, secretlen, sa,
salen, 3600 * NGTCP2_SECONDS,
t) != 0) {
return -1;
}
return 0;
}
int generate_quic_connection_id_encryption_key(uint8_t *key, size_t keylen,
const uint8_t *secret,
size_t secretlen,
const uint8_t *salt,
size_t saltlen) {
constexpr uint8_t info[] = "connection id encryption key";
ngtcp2_crypto_md sha256;
ngtcp2_crypto_md_init(
&sha256, reinterpret_cast<void *>(const_cast<EVP_MD *>(EVP_sha256())));
if (ngtcp2_crypto_hkdf(key, keylen, &sha256, secret, secretlen, salt, saltlen,
info, str_size(info)) != 0) {
return -1;
}
return 0;
}
const QUICKeyingMaterial *
select_quic_keying_material(const QUICKeyingMaterials &qkms,
const uint8_t *cid) {
for (auto &qkm : qkms.keying_materials) {
if (((*cid) & 0xc0) == qkm.id) {
return &qkm;
}
}
return &qkms.keying_materials.front();
}
} // namespace shrpx