| // Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include <openssl/ssl.h> |
| |
| #include <assert.h> |
| #include <limits.h> |
| #include <string.h> |
| |
| #include <openssl/err.h> |
| #include <openssl/mem.h> |
| #include <openssl/nid.h> |
| |
| #include "../crypto/internal.h" |
| #include "internal.h" |
| |
| |
| BSSL_NAMESPACE_BEGIN |
| |
| DTLS1_STATE::DTLS1_STATE() |
| : has_change_cipher_spec(false), |
| outgoing_messages_complete(false), |
| flight_has_reply(false), |
| handshake_write_overflow(false), |
| handshake_read_overflow(false), |
| sending_flight(false), |
| sending_ack(false), |
| queued_key_update(QueuedKeyUpdate::kNone) {} |
| |
| DTLS1_STATE::~DTLS1_STATE() {} |
| |
| bool DTLS1_STATE::Init() { |
| // Set up the initial epochs. |
| read_epoch.aead = SSLAEADContext::CreateNullCipher(); |
| write_epoch.aead = SSLAEADContext::CreateNullCipher(); |
| if (read_epoch.aead == nullptr || write_epoch.aead == nullptr) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool dtls1_new(SSL *ssl) { |
| if (!tls_new(ssl)) { |
| return false; |
| } |
| UniquePtr<DTLS1_STATE> d1 = MakeUnique<DTLS1_STATE>(); |
| if (!d1 || !d1->Init()) { |
| tls_free(ssl); |
| return false; |
| } |
| |
| ssl->d1 = d1.release(); |
| return true; |
| } |
| |
| void dtls1_free(SSL *ssl) { |
| tls_free(ssl); |
| |
| if (ssl == NULL) { |
| return; |
| } |
| |
| Delete(ssl->d1); |
| ssl->d1 = NULL; |
| } |
| |
| void DTLSTimer::StartMicroseconds(OPENSSL_timeval now, uint64_t microseconds) { |
| uint64_t seconds = microseconds / 1000000; |
| microseconds %= 1000000; |
| |
| now.tv_usec += microseconds; |
| if (now.tv_usec >= 1000000) { |
| now.tv_usec -= 1000000; |
| seconds++; |
| } |
| |
| if (now.tv_sec > UINT64_MAX - seconds) { |
| Stop(); |
| return; |
| } |
| now.tv_sec += seconds; |
| expire_time_ = now; |
| } |
| |
| void DTLSTimer::Stop() { expire_time_ = {0, 0}; } |
| |
| bool DTLSTimer::IsExpired(OPENSSL_timeval now) const { |
| return MicrosecondsRemaining(now) == 0; |
| } |
| |
| bool DTLSTimer::IsSet() const { |
| return expire_time_.tv_sec != 0 || expire_time_.tv_usec != 0; |
| } |
| |
| uint64_t DTLSTimer::MicrosecondsRemaining(OPENSSL_timeval now) const { |
| if (!IsSet()) { |
| return kNever; |
| } |
| |
| if (now.tv_sec > expire_time_.tv_sec || |
| (now.tv_sec == expire_time_.tv_sec && |
| now.tv_usec >= expire_time_.tv_usec)) { |
| return 0; |
| } |
| |
| uint64_t sec = expire_time_.tv_sec - now.tv_sec; |
| uint32_t usec; |
| if (expire_time_.tv_usec >= now.tv_usec) { |
| usec = expire_time_.tv_usec - now.tv_usec; |
| } else { |
| sec--; |
| usec = expire_time_.tv_usec + 1000000 - now.tv_usec; |
| } |
| |
| // If remaining time is less than 15 ms, return 0 to prevent issues because of |
| // small divergences with socket timeouts. |
| if (sec == 0 && usec < 15000) { |
| return 0; |
| } |
| |
| if (sec > UINT64_MAX / 1000000) { |
| return kNever; |
| } |
| sec *= 1000000; |
| if (sec > UINT64_MAX - usec) { |
| return kNever; |
| } |
| return sec + usec; |
| } |
| |
| void dtls1_stop_timer(SSL *ssl) { |
| ssl->d1->num_timeouts = 0; |
| ssl->d1->retransmit_timer.Stop(); |
| ssl->d1->timeout_duration_ms = ssl->initial_timeout_duration_ms; |
| } |
| |
| BSSL_NAMESPACE_END |
| |
| using namespace bssl; |
| |
| void DTLSv1_set_initial_timeout_duration(SSL *ssl, uint32_t duration_ms) { |
| ssl->initial_timeout_duration_ms = duration_ms; |
| } |
| |
| int DTLSv1_get_timeout(const SSL *ssl, struct timeval *out) { |
| if (!SSL_is_dtls(ssl)) { |
| return 0; |
| } |
| |
| OPENSSL_timeval now = ssl_ctx_get_current_time(ssl->ctx.get()); |
| uint64_t remaining_usec = |
| ssl->d1->retransmit_timer.MicrosecondsRemaining(now); |
| remaining_usec = |
| std::min(remaining_usec, ssl->d1->ack_timer.MicrosecondsRemaining(now)); |
| if (remaining_usec == DTLSTimer::kNever) { |
| return 0; // No timeout is set. |
| } |
| |
| uint64_t remaining_sec = remaining_usec / 1000000; |
| remaining_usec %= 1000000; |
| |
| // |timeval| uses |time_t|, which may be 32-bit. |
| const auto kTvSecMax = std::numeric_limits<decltype(out->tv_sec)>::max(); |
| if (remaining_sec > static_cast<uint64_t>(kTvSecMax)) { |
| out->tv_sec = kTvSecMax; // Saturate the output. |
| out->tv_usec = 999999; |
| } else { |
| out->tv_sec = static_cast<decltype(out->tv_sec)>(remaining_sec); |
| } |
| out->tv_usec = remaining_usec; |
| return 1; |
| } |
| |
| int DTLSv1_handle_timeout(SSL *ssl) { |
| ssl_reset_error_state(ssl); |
| |
| if (!SSL_is_dtls(ssl)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
| return -1; |
| } |
| |
| if (!ssl->d1->ack_timer.IsSet() && !ssl->d1->retransmit_timer.IsSet()) { |
| // No timers are running. Don't bother querying the clock. |
| return 0; |
| } |
| |
| OPENSSL_timeval now = ssl_ctx_get_current_time(ssl->ctx.get()); |
| bool any_timer_expired = false; |
| if (ssl->d1->ack_timer.IsExpired(now)) { |
| any_timer_expired = true; |
| ssl->d1->sending_ack = true; |
| ssl->d1->ack_timer.Stop(); |
| } |
| |
| if (ssl->d1->retransmit_timer.IsExpired(now)) { |
| any_timer_expired = true; |
| ssl->d1->sending_flight = true; |
| ssl->d1->retransmit_timer.Stop(); |
| |
| ssl->d1->num_timeouts++; |
| // Reduce MTU after 2 unsuccessful retransmissions. |
| if (ssl->d1->num_timeouts > DTLS1_MTU_TIMEOUTS && |
| !(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) { |
| long mtu = BIO_ctrl(ssl->wbio.get(), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, |
| nullptr); |
| if (mtu >= 0 && mtu <= (1 << 30) && (unsigned)mtu >= dtls1_min_mtu()) { |
| ssl->d1->mtu = (unsigned)mtu; |
| } |
| } |
| } |
| |
| if (!any_timer_expired) { |
| return 0; |
| } |
| |
| return dtls1_flush(ssl); |
| } |